Saturday, December 31, 2011

Forecasters See New Years Eve Snow

There appears to be growing consensus that a windy snow event will occur from tonight into tomorrow. The National Weather Service, with an issuance of a full-fledged Winter Storm Warning, is particularly bullish on this storm with a forecast of 3-5 inches of snow.

Here's how forecasters saw things as of Saturday mid-morning, approximately 12 hours before the expected onset of snow. (More recent updates in red font.)

WCCO: 2-5 inches (2-4 per 5 p.m. news)
KSTP: 1-3 inches
FOX: no info available (3-5 per late a.m. Ian Leonard tweet) (1-3 at 5 p.m.)
KARE: 1-4 inches (2-3 per 5 p.m. newscast)
NWS: 3-5 inches (2-4 at 5 p.m.)
Strib: 1-3 inches (upped to 2-5 late morning)
MPR: 1-2 inches (1-3 per 3:30 p.m. tweet)
Weather.com: A slushy accumulation of less than one inch (2-4 at 5 p.m.)
Accuweather: A coating to an inch (1.9 inches as of 5 p.m.)
@NovakWeather: 4-7 inches

Some screenshots of morning forecasts:

WCCO

KSTP

MPR

Weather.com
@NovakWeather
Fox and Strib tweets at 11 a.m.

 A reminder that you can follow the Minnesota Forecaster on Twitter and Facebook.

Friday, December 30, 2011

Grades for Non-Storm of Late December

If you run into one of our fine local meteorologists, give 'em some love. They're probably feeling as down as anyone about our utterly uneventful winter weather, and now the majority of them have to live with knowing they predicted accumulating snow for the Twin Cities that essentially never materialized. And commuters, warned that they'd likely need extra time because of weather delays, potentially lost a little shut eye based on the forecasts. This was, by most assessments, a bust-o-rama.

Our ever-subjective grades for the non-storm of late December are as follows:

WCCO: B WCCO was the least gung ho on accumulating snow for last night and this morning. While WCCO viewers weren't lead to believe there'd be much snow, they were also lead to believe there'd be at least a little.

KSTP: D Forecast of 1-2 inches of snow meant they were 1-2 inches off. They were also slow to remove any chance of accumulating snow from the forecast, providing for at least the possibility of some as recently as mid-morning.

FOX: D- Steve Frazier's unabashed love of the "snow meter" not withstanding, FOX seemed to predict 1.5 to 2.5 inches of snow.

KARE: D- KARE predicted 1 to 3 inches, with 3 inches being the exception. In fact, 1-, 2- and 3-inches were all the exceptions.

Strib and NWS: F Predicted 1-3 inches. Need we say more.

MPR: B- MPR was on the right track with this storm, predicting a coating to an inch for the urban core. But there was no coating to be seen, at least if you lived in the shadow of MSP airport, the official measuring station. If these were awards, we might give MPR an honorable mention.

@NovakWeather: F With the most ambitious snow forecast, TMF's advising meteorologist was off on this one. But we're pleased to hear he's already dusting himself off and read to battle for another day. Keep the faith, Tom.

The Weather Channel: C- Comparatively speaking, TWC fared somewhat better than the local weather gurus, but they still predicted around one inch of white stuff that never came. 

Accuweather: F Inaccuweather. Need we say more?

Agree? Disagree? Share your thoughts on our grades in the comments section below.

A reminder that you can follow the Minnesota Forecaster on Twitter and Facebook.

Thursday, December 29, 2011

Rare December Snow Seen Headed for Twin Cities tonight


To varying degrees, Twin Cities forecasters are calling for snow to arrive in the Twin Cities late this evening. One to three inches appears to be the most common prediction. However, two notable outliers include MPR (coating to one inch) and The Weather Channel (around one inch). As of Thursday evening, here's what the fearless prognosticators see coming:

WCCO: Noncommital. Seemed to suggest that accumulations would be south and southwest of Twin Cities.

KSTP: 1-2

FOX: 1.5 to 2.5 per official snow meter

KARE: 1-3 by morning (but most areas two)

Strib: 1-3

NWS: 1-3

MPR: Coating to 1"+ of snow possible by Friday noon along the I-94 corridor including the metro

The Weather Channel: Snowfall around one inch.

Accuweather: 1-3

@NovakWeather: 2+ inches, potentially closer to 4 to the southeast

A reminder that you can follow the Minnesota Forecaster on Twitter and Facebook.

Saturday, December 24, 2011

Pattern Change, Are You Out There?

Local weather geeks and other weather-interested parties are growing restless at the continued lack of "interesting" weather in the Twin Cities. Some have suggested there are inklings of at least some sort of pattern change coming up late during the week following xmas. But, obviously, that remains to be seen.

Use this space to discuss the continued search for systems that may drop more than .2 inches of snow on the Twin Cities.

Wednesday, December 7, 2011

Scanning the Skies Moving Into Mid-December ...

The TMF host will be out of town for the next week and vowing not to check the grid (or weather in Minnesota). Here's a space to discuss any interesting weather that may materialize over the coming week.

By the way, here's where I was. A big front came through and the last two days saw considerable beach erosion along the coast in Playa Del Carmen.

Tuesday, December 6, 2011

A New Weather Grader in Town

For those interested in seeing how local forecasters perform in select areas of the country (including Minneapolis/St. Paul), there’s a new service that can tell you just that. Weatherist.com, which launched in Beta in late November, aims to assess the comparative accuracy of television forecasters and select other sources.

A sample "Leaderboard" of Minneapolis/St. Paul forecasters from Weatherist.com

The site features a number of interesting features including the ability of individuals to post their own forecasts and have them analyzed alongside the pros. The site also develops a “most probable forecast” that’s derived from the performance of “hot” forecasters.

According to Dave Chung, co-founder at Weatherist, the goal is to bring accountability to the weather forecasting industry and to provide a critical voice for consumers in an industry that has never had one. We applaud Weatherist’s ambitious goal and hope it’s successful.

If you’re curious to see an approach that’s far more scientific than ours, do check it out. And, as a new startup, Weatherist.com is interested in gathering as much feedback as possible. Feel free to leave your comments below.

Sunday, December 4, 2011

Grades for the Dec. 3-4 Snow Event


Here is our assessment of the Dec. 3-4 storm along with a few thoughts.

Overall
We think if most forecasters are honest with themselves, they’d say that this storm slightly exceeded predictions and had more energy in the second half of the storm than many expected. Although our perspective is intensely Twin Cities-focused, the storm was generally well predicted from an overall regional perspective with regard to storm timing and general trends.

Forecast Summary
As of Friday evening, approximately 24 hours before storm onset, the vast majority of forecasters predicted 1-3 inches. The only exceptions were the national forecasters, who predicted less. For our assessment purposes, we base the majority of our grading on forecasts made 24 hours before a storm. Once the storm is underway, it becomes more an exercise in nowcasting, which is an art in and of itself.

The Result
Snowfall at the Minneapolis/St. Paul airport was 4.4 inches and from a graphic provided by the National Weather Service, the best assessment would be to call this a 2-5 or 3-5 inch storm, depending on how wide you want you want to define the metro area.

Grades
On the whole, we’d tend to give most forecasters a B with perhaps an A-/B+ to the National Weather Service who noted the possibility of 3-5 inches on Saturday morning, when all other forecasting outlets remained at 1-3 inches. Accuweather would rate a D for predicting .8 inches of snow.

A Note on Self Aggrandizement
Nobody can fault forecasters for making mistakes. They’re human and meteorology is an inexact science. While we try to provide a record of their predictions (against actual results), we also emphasize the communication aspect of weather forecasting and how forecast presentations fall on the eyes and ears of the average viewer drawing “reasonable man” conclusions to what they’ve heard.

While it doesn’t thrill us to watch a forecast where the met manages to avoid saying something that shows a connection to the viewer such as “if you watched us earlier, you know that we thought there’d only be one more inch to fall… but obviously, we ended up receiving more than that,” we can live with that. But what we find credibility-damaging is when the met falls over himself (or herself, should that be the case) patting himself on the back when in reality he missed the forecast!

On Saturday night, Fox9’s Steve Frazier commented over and over how the storm played out exactly as he’d expected (he even excused himself for patting himself on the back numerous times on the forecast). His presentation included snowfall amounts that he admitted were gathered when snow was still falling steadily and were likely to go higher. He noted that a measurement at the Fox 9 studio in Eden Prairie (where one would expect totals to be lower than in places like the airport, St. Paul and points east) revealed that about three inches of snow had fallen. The amounts he displayed reflected a 1-3 range of snow across the metro area. Blithely ignoring his comment that the totals were likely to go higher, he went on to use the incomplete estimates to make his case that he nailed his 1-3 inch forecast.

Minutes after his presentation, an official measurement from the airport came in at 4.2 inches, providing indisputable proof that Frazier’s 1-3 inch conclusion was off. Ensuing snowfall reports suggested that a truer metro-wide forecast would have been something like 2-4 or 2-5 inches. We find his presentation – sloppy at best and disingenuous at worst – the kind of thing that doesn’t sit well with viewers who watch faithfully.

Follow The Minnesota Forecaster on us on Twitter and Facebook for updates. 

Friday, December 2, 2011

One to Three Seems To Be the Consensus

Note: As of Saturday morning, some forecasters were revising expected snowfall amounts. The NWS now calls for 3-5 inches, WCCO now calls for 2-4 inches, while KARE, Strib and KSTP remain at 1-3 inches. MPR (6:30 a.m. update) says Twin Cities remain on the northern fringe of the snow band (indicated as 2-6 inches) with northern suburbs like Blaine expecting one inch. Accuweather still calling for "a bit of snow" totaling .8 inches.

Most Twin Cities weather prognosticators were singing the same tune on Friday evening, about 24 hours before the expected onset of what appears to be a relatively minor snow event. Here's a summary we put together from the mid-evening news segments.

WCCO: 1-3 (but used model showing no snow)
KSTP: 2
FOX: 1-3
KARE 1-3
NWS: 1-3
Strib: no update since last night
MPR: "For the Twin Cities metro, snow will be heaviest toward Lakeville, where three inches look to be a good bet for now."
Novak: 1-3
Weather Underground: 1-4
Accuweather: .9 inches
Weather.com: "Less than an inch" Saturday and another "less than an inch" Saturday night.

Check on us on Twitter and Facebook for updates.

Wednesday, November 30, 2011

Is Interesting Weather on the Way?

Forecasters are finding the weather pattern to become more active. Use this space to talk amongst yaselves!

Sunday, November 27, 2011

While We Wait for Interesting Weather....Share Your Weather Links

As snow lovers and winter weather enthusiasts wait for "interesting" weather to come through the region, it's been suggested that we use this break in the action for followers and weather enthusiasts to post their favorite weather sites, links, etc. If you're inclined, provide some of your bookmarked favorites so we can share the weather love.

In the meantime, we'll all keep scanning the horizon for something, anything that's interesting.

Sunday, November 20, 2011

For Central MSP, Snowfall Surprises Twin Cities Forecasters


Whether or not you think this was a well-predicted storm probably depends on where you live. For purposes of The Minnesota Forecaster and our assessment, we consider what happens at our urban St. Paul headquarter location, approximately three miles south of 94 and two miles east of the Mississippi. The official snowfall recorded by the MSP airport was 3.0 inches, which was essentially the same amount received at TMF.

In the big picture, this storm was fairly well predicted. However, upon closer inspection – specifically the snowfall in the close-in metro – the performance was lacking. MPR’s Paul Huttner provides a very good synopsis of the general forecast performance and challenges here. Due to the on-again, off-again nature of the storm, we didn’t track each and every forecast leading up to the storm as we might have. Here’s our subjective assessment of the performance of local forecasters.

Essentially, all weather prognosticators missed the band of heavier snow that set up over the south metro. As of Friday night, most forecasters were calling for 1-2 inches of snow at best for the Twin Cities. All forecasters also stated that metro snowfall amounts would be higher on the northwest side; some, such as KARE11’s Jerrid Sebesta, even suggested that southern suburbs like Burnsville might not receive any snow (Burnsville recorded 3 inches).

We felt that Fox9’s Ian Leonard minimized this storm a little too much. His mantra for the storm in the days leading up to the storm was “more wet than white” and he attempted to distance himself from others’ storm hype that he felt was unwarranted. While in the end this was clearly not a megastorm, we think the large number of metro-area traffic accidents reflects that it was a legitimate storm that justified solid warning if not hyping.

On Saturday morning, the Star Tribune’s Paul Douglas, while rightfully declaring that he thought snow amounts would be toward the upper end of the 1-3 inch range, forecast that the snow would not stick to roads until closer to 5 p.m. as darkness descended. This, in fact, was wrong, and was no small error given the number of people relying on his information.

As late as early morning Saturday, MPR maintained an expectation of a coating to an inch. MPR upgraded forecasts amount by early afternoon to reflect higher snowfall projections.

We also believe the National Weather Service was inexplicably slow in issuing a snow advisory. While one can argue that the first snow of any kind justifies the issuance of an advisory, the band of heavier snow that began to set up over the south metro shortly after noon should have triggered an advisory. This seemed a missed opportunity for public awareness about deteriorating road conditions. The advisory was issued close to 3 p.m.

As we said, we didn’t watch every forecast from every media outlet leading up to the storm. Did you see any forecasts or official comments that you thought were especially on or off for this storm forecast?

Friday, November 18, 2011

MSP Forecasters Place Their Bets on Season's First Snow


As of Friday night, most forecasters were predicting a minimal snowfall for the Twin Cities of 1 to 2 inches. The Weather Channel predicts 2-4 inches.  The following are forecasts from most of the major outlets. Note there are some differences among forecasters as to where the region's largest snowfall will occur. For new visitors, Minnesota Forecaster can be found on Facebook and Twitter.

AccuWeather


MPR Weather

Weather.com
NWS
WCCO
KSTP
Strib/Paul Douglas
Novak Weather
KARE

Wednesday, November 16, 2011

At Last, Something to Talk About

As of Wednesday evening, there remains great uncertainty about what will actually happen on Saturday. Weather.com reflects "up to 6 inches of snow" whereas some of the local outlets are thinking it will be more wet than white. And is this really much of a storm at all or is it just that Minnesota weather enthusiasts are starving for something to talk about?

Monday, November 14, 2011

The Boring November Continues ... Storms, Cold in Sight?

Minnesota's weather enthusiasts haven't had much to cheer about in several months. Through mid-November, it's been dry and mild. Some think the weather may get interesting the weekend of Nov. 19-20; others think the boring weather will continue through at least Thanksgiving. What says you?

Friday, November 4, 2011

Snow Possiblities for Next Week?

The local weather Twittersphere has been filled with talk about a possible snowstorm for the middle of next week. As of this writing, most forecasters seem to think it will pass southeast of the Twin Cities. What do you think/hope will happen?

Saturday, October 29, 2011

The Winter Forecast Collection

The much awaited winter forecasts are coming in from various local forecasters. As best we can determine, these are the various forecasts to date:

KSTP's Dave Dahl released his forecast on October 27 and predicts 75 inches of snow for the Twin Cities. Even better, Dave laid out his snowfall projection by month. We're inclined to think he nailed the October snowfall forecast.


MPR's Paul Huttner weighed in with his forecast on October 26. He forecasts average temperatures for the December through February period and a seasonal snowfall total between 50 and 60 inches.

The Star Tribune's Paul Douglas calls for winter temperatures to average 3 degrees cooler than normal and snowfall to total between 50 and 55 inches.

As a group, the average snowfall prediction of those taking the Minnesota Forecaster poll was
61.9 inches. Please take the poll at right to tally your guess as to how winter's temperatures will fare.

Minnesota Forecaster, whose predictions are based on the amount of shedding experienced by the family dog, predicts temperatures averaging .6 degrees above normal with seasonal snowfall of 43.1 inches breaking down as follows: October: 0, November: 4.1, December: 10.7, January: 9.2, February: 4.1, March: 11.2 inches, April: 3.8.

Readers, are there any other forecasts out there that we may have missed?

Thursday, October 20, 2011

A Statistician Weighs In On the Upcoming Twin Cities Winter

One of TMF’s followers, Rigil Kent, is a weather enthusiast and statistician. He provided a prediction of winter snowfall and temperatures based purely on statistical analysis and the historical effect of La Ninas. He has compiled datasets over the years from weather records from a variety of different sources, including NWS, Accuweather, etc

“I thought I would try a systematic approach to this,” says Rigil. “I took the average snowfall of the La Nina winters, plus a random correction taken from the statistical distribution that best approximates winter snowfall in the Twin Cities since records started.” Rigil came up with a result of 62.1 inches of snow.

We asked Rigil to take a shot at predicting temperatures as well. “Temperatures are a bit trickier as the official NWS means are updated every 30 years or so. To keep things simple, I used the current averages and looked at the discrepancies observed during La Nina winters plus some random corrections.”

The results were enough to send chills down the spine of even the most hardy winter Minnesotans. Based on the statistics, Rigil predicts February and March to be far colder than average with December, January and April temps running slightly below normal. Here are his monthly temperature predictions for November to April:

November. Minimum temps .9 above average; maximum temps .4 above average
December: Minimum temps .5 below average; maximum temperatures 1.1 below average
January: Minimum temps .8 below average; maximum temperatures 1.0 below average
February: Minimum temps 3.8 below average; maximum temperatures 2.9 below average
March: Minimum temps 4.4 below average; maximum temperatures 5.3 below average
April: Minimum temps .4 below average; maximum temperatures 2.2 below average

Rigil’s quick to point out that his model is a purely statistical one and does not take into account any meteorological variables for now. He’s currently working on a model to predict snowfall for the Twin Cities year by year that takes into consideration several indices like ENSO (La Nina/El Nino), the Pacific Decadal Oscillation (PDO), the NAO, etc.”

Weather/statistical geeks may be interested in attending an upcoming lecture at the University of Minnesota. The lecture, conducted by Professor Adrian E. Rafferty from the University of Washington, is titled Probabilistic Weather Forecasting Using Ensemble Bayesian Model Averaging and takes place on Thursday, Oct. 27 at Ford Hall 115 at 3 p.m. The lecture will look at ways to post process numerical model ensembles (GFS, etc.) to obtain better calibration. As Rigil points out, “To a Bayesian statistician with a passion for weather like myself, you really can’t ask for more.”

A reminder that you can follow The Minnesota Forecaster on Facebook and Twitter.


Thursday, October 13, 2011

What Will Winter Bring?

The answer, of course, is how the heck do we really know? Ah, but that won't keep the weather-obsessed populace that is Minneapolis/St. Paul from wondering. And with that, we were wondering what your thoughts were regarding the upcoming winter. Please take the poll at the right.

What does the NWS say about this winter?
Given the talk of another La Nina forming -- and Accuweather's already infamous prediction of another brutal winter for these parts -- we were curious to know exactly how strong the correlation is between La Nina and a cold, snowy winter for Minnesota. We checked with the Twin Cities branch of the National Weather Service and this is what they told us:

It is true that there are signs of a La Nina returning for this winter out in the equatorial Pacific. About 70-80% of the time there is a La Nina, temperatures in MN for the Dec/Jan/Feb 3-month season are below normal (with about 60-70% of those winters experiencing above-normal snowfall). The Climate Prediction Center shows the historical correlation to the ENSO phase and temp/precip patterns across the US at this site.

Our own guess -- based on gut, not science -- is for average temperatures, slightly below normal snowfall and one to two short tropical getaways.

What are your gut thoughts on the winter ahead. Will it take a while to get going? Will it start with a vengeance? Will it feel like a St. Louis winter?

Sunday, September 11, 2011

Forecasters Predict Weather Whiplash

The National Weather Service forecasts a high of 90 on Monday ... and a low of 39 for Wednesday night. Yowser....How do you feel about this sobering development?

Sunday, August 28, 2011

Hurricane Irene: In Her Own Words


It all started when my boss informed me that the U.S. hadn’t sampled our cyclonic wrath in three years. Indeed, the last of our brethren to strike the Big 48 was Ike, who pushed Texas around in 2008. But since then, nada.

“Irene,” he uttered in hushed tones, “the world’s most powerful country has all but forgotten about us. We can’t have this. Would you consider becoming a major hurricane?”

I considered the tall task. Did I really want to drag myself through the little Caribbean islands and the always-risky voyage through the Bermuda Triangle? I’d heard of so many brothers and sisters who got sheared to bits there or were otherwise destined to “merely affect shipping lanes,” a euphemistic death sentence that no hurricane worthy of its salt ever wants to hear. And besides, were I to choose a path of widespread destruction, I’d bring dishonor to my pacific name.

As I began to mull things over, calls came in to the corporate office in our secret location on the coast of West Africa (where we also do much of our manufacturing). A CNN media relations rep pleaded with our CEO. “Bachman’s gaffes get us a little attention and the “Libya thing” helped, but we really need a megastorm to get us back on the cable radar.” Evidently, he was desperate. “Look, we’ll even give you the foreboding death march music to lead in and out of the story – the music we usually leave for deaths and wars.”

I was tempted, but I was still on the fence. Who really wanted to endure the suffocating detailed analysis and examination that would go with the territory? After all, I wasn’t about to run for president.

Then came Jim Cantore, the Jim Cantore from The Weather Channel, who could make a sprinkle sound torrential. He asked to speak with me personally. He told me in no uncertain terms that as long as I could show a little potential – “just give us a little purple convection south of the Carolinas” were his words – he’d make me a star.

And so I took the dive. I signed the papers in a humid conference room on August 14, and by the next day, I was kicked off into the Atlantic in the dark of night and into the great unknown, a lonely tropical wave set on making something of myself. I played Joe Jackson’s “Steppin Out” over and over in my head to psych myself up.

Early on, I established a singular goal: Gain the glory for myself (and the cable stations) but spare the good people of any real, extensive damage. To accomplish this I’d need to exhibit both atmospheric prowess and a magician’s deception.

Initially, the trek westward was uneventful. After cruising past the Cape Verde Islands, I was slow to develop thunderstorms and showers in my proximity. At that juncture, the weather geeks called me unorganized and “broad in appearance” – to which I always wanted to say, “Well, I am a broad!” All kidding aside, however, broadness was a distinguishing quality of mine that would stay with me to my dying days.

By August 19, I started exhibiting what meteorologists call a convective structure, which basically meant I was ready to rock and roll as a tropical force. The next day, they flew an aircraft into my inner core and found I had a circulation. I had arrived, and I was getting some serious attention. Soon after, they started calling me by my official first name.

Initially, the experts had me slated to take my talents to South Beach. But while passing the island of Saint Croix, I decided a curve northward might allow me – with the help of CNN and TWC – to terrorize the millions in the big megalopolis.

Now that I was on the big stage, I had to get dolled up. To this point, I’d been chastised for having a “ragged eye” and so I improved my appearance. For a short time at least, I wore the classic look of a well-defined eye with “good outflow on all sides.” I even caused a little havoc on North Carolina’s Outer Banks, but that was mainly for show.
I’d accomplished the goal of looking menacing, which, in so many ways, was all I ever really wanted.

The pressures and trappings that go with being a major hurricane can be overwhelming. Once you begin to ascend the Saffir-Simpson hurricane scale, there’s really only one place to go. The media pressure to become a Cat 4 or Cat 5 can be immense. Katrina, while good for our industry, raised the bar impossibly high.

I followed orders to a tee, maintaining a dead-on track to New York and forcing the city to take extreme and unprecedented precautionary measures. This kept the doomsday scenario alive – and television ratings high. I’d already achieved a modicum of success, and regardless of what happened from this point forward, the boss would be thrilled.

Sadly, I began to lose interest and commenced a slow limp to the finish line. I was praised for my impressive wingspan, even compared in size to the state of Arizona. But my girth not withstanding, there was little gas left in the tank. For all intents and purposes, my own batteries died, ironically enough, as I approached New York’s Battery Park.

In all, I’d made three landfalls and caused considerable inland flooding, a rather estimable accomplishment. However, the media trashed me, saying I never delivered on my forecasted wallop. That’s what happens when you’re unfairly compared to truly legendary hurricanes.

Still, it’s amazing how quickly they forget about you. By Sunday afternoon, mere hours after I’d arrived in New York, Cantore called headquarters, asking, “Who else can you send us?”

But I’ll always hold on to one thing: If you can scare them in New York, you can scare them anywhere.

===
Remember,  you can follow The Minnesota Forecaster on Twitter and like us on Facebook

Friday, August 26, 2011

How Will Hurricane Irene Affect Minnesota?

Misleading headline. It won't. But keeping with our mission of evaluating weather forecasters, this can be a space for comments about forecasting for Hurricane Irene.

Tuesday, August 16, 2011

Early Prognostications For State Fair Weather

Dave Dahl appears to be the first local forecaster to put out a forecast for the state fair. The following appeared on the KSTP weather blog in the late afternoon of Tuesday, August 16.
Highs will probably climb quickly through the 80s and into the 90s by the start of the Minnesota State Fair.  Right now it looks as though we'll have the average amount of rainy days during the Fair, which means we can plan on around 3 of the 12 days to be a little wet.
Thanks to the always-brave national weather outlets, we can report the following forecast for the opening day of the fair:
Intellicast: Sunny, 80
Weather.com: Sunny, 81
Accuweather: Sunny, 86
Weathertrends360.com: Sunny, 82
Anyone else have an educated guess on the state fair weather?

Friday, August 12, 2011

Does Minnesota Really Have the Most Jekyll and Hyde Weather?


We’ve been wearing our part-time weather consulting hat, working with ForecastAdvisor, a leading provider of information and accuracy assessment for the weather geek/enthusiast, to help present information that shines light on the most weather-changeable cities in the U.S. They've created an analysis of weather variability along with individual city listings that you might find interesting. The listing, which includes the Twin Cities, can be found here.

If you’re inclined to provide feedback on what you find there, we’d love to hear it:
  • Does the analysis make sense to you?
  • Do the results surprise you?
  • What other information would be interesting to know?

Thanks for any feedback!

Tuesday, August 9, 2011

Weekend Forecast Analysis for Aug. 6-7 - No Clear Winners

We did another extended weekend forecast analysis for this past weekend's weather (Aug. 6-7) as predicted on the night of Sunday, July 31. There were no clear winners for the forecast and what seems most noteworthy is that none of the weather outlets latched on to the 6-degree decrease in temps that occurred from Saturday to Sunday.

The forecasts:(Sat/Sun)
KARE: mid 80s nice/low 80s chance of t-storm
KSTP: 86/86, 30% each day
FOX: 86/86, chance t-storm Saturday night
WCCO: 86/85 (chance t-storm on Sunday)
NWS: 84/86, slight chance of t-storm each day
Accuweather: 84 nice/85 t-storm possible
Weather.com: 83 partly cloudy/81 scatter t-storms
Intellicast: 82 partly cloudy/80 (scattered t-storm)
Strib: 85/84 scattered pm storms each day

What actually happened:
Saturday: Partly cloudy, high 88, t-storms
Sunday: Partly cloudy, high 82

Is Summer Over?

Minnesota heat lovers have reason to think that the good stuff is over. Thoughts?
Photo taken in the evening of Aug. 9.

Tuesday, August 2, 2011

Followers Beware: Tweets on Seemingly Inevitable Storms Often Wrong

This morning provided another reminder that, in our eyes at least, tweeting meteorologists are putting too much predictive emphasis on emerging radar echoes and, in their efforts to be precise, forgetting that storms die out, rebuild and change directions. At a minimum, they'd be wise to at least use more cautionary wording like "may" or "if it holds together" when discussing the movement of storms seemingly headed for the metro.

This morning, Sven Sundgaard detailed with seeming certainty the arrival of morning storms per the graphic below. With our hopelessly untrained eye, we looked at the radar shortly after 7 and wondered if that would actually happen. For one, the storms were a relatively long way away (though moving very quickly) and it seemed puzzling that one could speak with such certainty given the distance the storms still had to travel. For the fun of it, we tweeted close to 8 a.m. that we had our doubts. But it wasn't until close to 9 a.m. that Sven acknowledged that the storms indeed were going to miss the most of the metro.


Tweet issued at 7:07 a.m.



Amateur tweet at 7:59 a.m.
Tweet issued at 8:44 a..m.

Conversely, we did note that Jonathan Yuhas, whose tweets were off the mark during the day and evening of the U2 concert employed wording that acknowledged merely the possibility of storms arriving in the metro.


 It's baffling to us why many forecasters continue to make pronouncements of impending storms in such certain terms, particularly when storms are still a decent distance away. Why not use tweets to put us on alert and then communicate with more certainty when storms are truly on the doorstep. Doesn't that make more sense?

Remember,  you can follow The Minnesota Forecaster on Twitter and like us on Facebook

Monday, August 1, 2011

The First of August Brings a Summer Bust

By this time, everyone knows that this was one of the bigger weather busts in a while. And, it was unanimous, so there's no point in comparing the performance of individual forecasters. No weather outlet suggested anything close to what happened today -- both in terms of forecast temperatures and the timing and coverage of the storms. It even seemed that the morning nowcasts somewhat missed the boat. When it became apparent that storms loomed with greater significance than expected, several forecasters anticipated a mid-morning arrival of the storms, when in fact it seemed they held back a bit to produce a stronger punch shortly after noon.

No mention of today's forecast evaluation could go without noting the irony of the coolest day in the last week being the one where an official heat advisory was issued. For that matter, it seems the NWS really should have issued a heat advisory for yesterday, when heat indexes were truly oppressive.

Any professional mets out there have any thoughts on what happened from an informed, meteorological perspective? Did the warm front take longer to come through? What materialized that wasn't anticipated by the beloved models?

Tuesday, July 26, 2011

Weather.com Nails Last Weekend's Extended Forecast Temps; KSTP Best of Local Forecasters

If you're like most people, you like to start thinking about your next summer weekend just about the time the current weekend winds down (at least that's how we like to think!). That's the approach we took on Sunday, July 16. That evening, we gathered the temperature forecasts for the ensuing weekend (July 23-24) and plotted them on our handy Excel spreadsheet as follows (note: KARE11 does not formally forecast beyond five days, but Sven Sundgaard suggested that "90s were quite possible for the weekend"):


We thought that this forecast had a fair amount of challenge because there was a major heat wave that was about to hit high gear early in the week for a somewhat uncertain duration. The following table summarizes the forecast error for each of the weather oulets (we arbitrarily used 92 as the predicted temperature for Saturday and Sunday for KARE).

 
Amazingly, Weather.com (The Weather Channel) was exactly right for both days' forecasts. Based on our analysis, the rank order of all outlets was:

#1: Weather.com
#2: KSTP
#3: Intellicast
#4/#5: NWS/WCCO
#6: Fox
#7: Accuweather
#8: Star Tribune
#9: KARE

There's not all that much to take from this. It is, after all, just a one-weekend extended forecast sample. Were we do to this for every weekend over the course of a longer time -- months to a year -- the results would be a lot more meaningful. Also, and just as importantly, we didn't record the forecast as it related to sky conditions/storms, etc.

Sunday, July 24, 2011

A Case of Nowcasting Gone Terribly Wrong

We've been meaning to post a small philosophical essay about the pros and cons of nowcasting, the practice of giving short-term updates on weather activity that's generally not considered forecasting. While that post will have to wait for another day, today's weather forecaster analysis wouldn't be complete without reviewing today's "nowcast" tweets of @JonathanYuhas. We're not trying to pick on Jonathan, but it sure seemed like everything he said turned out to be completely wrong. The following chronicles a night of forecasting-challenging weather juxtaposed with Jonathan's nowcasting tweets.

We begin tracking Jonathan's tweets about 4:45 p.m. as the Twins game was moving into the later innings.


While the quantification of a possible "25-minute rain" seemed overly precise, particularly since there was no guarantee the rain would even arrive, it was a nice little heads up, both for fans watching on TV and fans attending the game.

About 15 minutes later, Jonathan issued his next tweet, delaying the possible arrival time of a 25-minute rain to 5:30.


As 5:30 approached, Jonathan determined that the rain was breaking up, and called off the possibility of rain for Target Field. Notably, he stated that the storms WILL fire up over the next 7 hours (not "might" fire up):


Next, Jonathan decided it would no longer be a stormy night, mentioning the possibility of only light showers.


By approximately 8:45, Jonathan minimized the threat of rain even further, calling for the possibility of sprinkles at worst for the U2 concert-goers. He pronounced that the cooler airmass over the Twin Cities precluded the possibility of any severe storms.


But just as Jonathan seemed to kiss any chance of significant rain goodbye, things started to change. Shortly after that, the radar began to blossom. Light green echoes turned to dark green, and then quickly to yellow, orange and red.



Jonathan took note of the changing radar and alerted concert-goers about the possibility that some rain and thunder could "graze" the U2 concert.


At about this time, 1" hail estimates were coming in from Brooklyn Park. The line of storms began to sag southeast and back-build to the west. At 9:49 p.m. the National Weather Service issued this special statement noting significant storm activity for the University of Minnesota, site of the U2 concert:
GUSTY WINDS OF 30 TO 40 MPH ORIGINATING FROM THIS STORM ARE LIKELY TO BE EXPERIENCED IN MINNEAPOLIS...ST. PAUL...AND LOCATIONS IN BETWEEN THE DOWNTOWNS...INCLUDING THE UNIVERSITY OF MINNESOTA.
Shortly thereafter, reports of torrential rain and cloud-to-ground lightning were reported at the University of Minnesota's TCF Bank Stadium. At 10:19 p.m, here was the Weather Underground radar depiction:



Unfazed by his missteps that seemed to occur with every tweet, Jonathan, the consummate professional, plowed forward, giving his followers one last concert update:


A final tweet, five minutes before 11 p.m., pronounced the storm still sitting over the U of M:


In fairness, other forecasters noted some of the same general trends, but their tweets weren't quite so precise or quite so wrong. We do think Jonathan deserves credit for actively tweeting in the first place, as it reflects his passion for what he does (and an understanding of the emerging importance of social media in weather communication).

Still, tonight's events raise a few questions: Is nowcasting, particularly in a convective summer environment, really such a good thing? And is too much credence given to every turn of the radar, sometimes at the expense of seeing the big picture of possibilities?

Friday, July 22, 2011

Severe Saturday?

Twin Cities forecasters are talking about the possibility of severe storms on Saturday, which means Twins fans and U2 fans can't rest easy. Weigh in with your thoughts here.





Tuesday, July 19, 2011

How Legitimate Are All These Heat Index Readings?

How Reliable Are Weather Stations?
With higher and higher heat index reports coming in from parts of the state (mostly western MN) like competing bids at a Sotheby auction, we wondered how reliable such readings might be. We asked a National Weather Service meteorologist for an opinion on the legitimacy of such readings and how often the NWS might review or approve weather stations beyond the larger ones such as the Minneapolis/St. Paul airport. Here's what he had to say:
The first-order stations with ASOS (Automated Surface Observing System) instruments (such as the MSP airport) are rigorously monitored and maintained by NWS technicians. They undergo at least routine maintenance, and when errors are detected non-routine maintenance is performed. As for all the other stations out there -- FAA, AWOS (Automated Weather Observing System), MNDOT system, etc. -- I am not aware of the maintenance they undergo, but based on my experience I believe it is less rigorous than the NWS maintained stations.

If a record high dew point is observed in the state (which may have happened I believe) there will be a much closer look done, likely by the state climate office consulting with the local NWS office and possibly some other folks at national climate centers.

Why Isn't Wind Factored Into the Heat Index Calculation?
If you're like us (which is to say weather enthusiasts with very little scientific knowledge), you might wonder why wind conditions don't factor into the heat index. At some level, it would seem that wind -- even a warm, humid wind -- would slow the effect of heat on the body. Of course a scientific explanation trumps a misinformed hunch. Thanks to Nick Benson (@Ottergoose on Twitter), we received a well-reasoned explanation:
The heat index doesn't take wind into effect because heat loss at high temperatures comes from perspiration, not convection. Only air cooler than you can actually cool you down; sweating only works if the air has capacity to absorb your perspiration. Think of air as a mop; if it's saturated, the floor will stay damp no matter how quickly you scrub it. Likewise, saturated air blowing over you will have a minimal impact on absorbing perspiration (cooling).
And so ends a Simply Science version of TMF.

Will Wednesday Provide the Century Icing to the Heat Wave Cake?

Tuesday's 119 heat index
OK, "icing" may not be the right word, but you get the drift. Will Wednesday delivery the coup de grĂ¢ce for this record-setting heat wave? The majority of local forecasters are predicting that Wednesday will indeed be the hottest of the current heat wave. (The national forecasters, not so much.) As of late afternoon on Tuesday, here's how the weathercasters saw Wednesday:

WCCO: 100
KSTP: 100
FOX: 97
KARE: 100
NWS: 97
Weather Channel: 96
Accuweather: 96
Intellicast: 95
Star Tribune: 99

Monday, July 18, 2011

Widely Predicted Heat Wave Finally Arrives in Earnest. Eighties or 90s Next Weekend?

Heat wave update as of 4 p.m.
Until today, the heat wave that was so universally predicted for so many days didn't pack the punch we were led to believe. Today, the forecasts came true. For the first time in many days, the forecast high temperature and heat indexes were reached, and even exceeded. By late afternoon, the heat index of 112 in Minneapolis was the highest of any major city in the U.S. Take a bow, y'all.

Here's a summary of how the heat wave is "performing" against forecasts made on Friday night.



Here's a summary of the over (under) prediction of the heat wave to date for the period since Friday night. At this juncture (and assuming the 98-degree high for Monday holds), KARE has the best forecast record for the period measured; Fox, the worst.


80s or 90s for Next Weekend?
Finally, in another test of the extended outlook forecasting ability of the weather mavens in our midst, here's next weekend's forecast temperatures as of last night's (Sunday night) evening forecasts. (Note: KARE does not provide specific forecasts beyond day 5. The "90s" information was provided anecdotally.)

Saturday, July 16, 2011

"Massive Heat Wave" Off to Tepid Start

The 90 Run Has Yet to Begin
A funny thing happened on the way to that streak of 90s ... it hasn't yet begun. Despite universal forecasts of temperatures above 90 today, the temperature reached "only" 87. The highest heat index for the Twin Cities today was a not-off-the-charts 97. It seems questionable at best as to whether an excessive heat warning was really necessary.

The 80-81 degree dew point predicted by the Star Tribune weather columnist also never materialized. While the dew point did reach a tropical 77, it did not approach the record to near-record high dew point predicted in several recent Star Tribune blog posts.

A Forecasting Slump?
Perhaps you've noticed, but the weather gurus haven't been at the top of their game the last three days. The original prediction for heavy rain (to be measured in inches) was for Wednesday night into Thursday. Yet, Thursday saw only .13 inches of rain. The Friday forecast generally (and yes, we're generalizing about the forecasts) called for the chance of a few spotty storms and a high in the upper 80s. However, Friday saw the first bout of torrential rain (more than two inches) and a high of only 77. And as of Friday night, most forecasters called for only a small chance of rain overnight on Friday. In fact, more torrential rain fell in the early a.m. hours of Saturday. It all serves as another reminder that forecasting, particularly amid the chance of convective storms, is a tough task.

Weather.com Seems a Little Nuts
Weather.com is displaying an odd range of forecast temperatures for Sunday. It forecasts 96 for Minnetonka, 101 for St. Paul and 104 for Minneapolis, including the zip code for the Mpls/St. Paul airport. The official weather.com forecast is: Intervals of clouds and sunshine. Record high temperatures expected. Heat index near 120F. High 104F. Winds S at 10 to 20 mph.

Recapping the Original 7-Day Heat Wave Forecast
Here's an updated comparison of heat wave predictions made on Friday night to the actual temperatures reached so far. Note that all predictions for the first two days of the period have been well above actual.

Friday, July 15, 2011

File Under: Things That Don't Seem Logical

Here is a depiction of the latest heat watches and warnings. The red-shaded areas represent Excessive Heat Warnings; the lighter-colored shading represents Excessive Heat Watches. It makes some sense that the always-cooking urban core could be under a warning when surrounding areas are under watches. But what makes less sense to us is why there would be a warning for two counties (one in Minnesota, one in Wisconsin) that are midway between the Twin Cities in Duluth. Is the heat really expected to arrive in such an unusual arc pattern? Or is the thinking that the two counties didn't receive much rain today and thus will heat up faster? Hmm.... Professional meteorologists, what can you tell us?

Read It and Weep - Your Universal Heat Wave Forecast

Interestingly enough, the greatest amount of variability in the 7-day forecast is for today. Blue outline marks forecasts that (sort of) stand out as being cooler than others; red outline marks forecasts that stand out for heat. If you're not desiring a heat wave, you should be rooting for the Intellicast forecast, which "only" forecasts five consecutive days in the 90s.

The following information is based on forecasts collected this Friday morning.


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Wednesday, July 13, 2011

National Forecasters Outperforming Locals for This Week

Last Friday night, temperature trends varied by forecast outlet in a rather interesting way. Virtually all national forecasters (weather.com, accuweather and intellicast) saw the current week as being cooler than the local prognosticators. The national weather providers envisioned several days in the 70s, whereas the hometown studs maintained temps in the 80s throughout. Given the rather odd dichotomy in temps, we captured the forecast for later review. Our thinking -- our guess, really -- was that the locals would be better at forecasting local weather than the nationals. However, as this week has played out, and given the forecast for Thursday, that's not been the case. If you had your money on Weather.com, you were a winner.

Tuesday, July 12, 2011

Summer in the City: All Forecasters Predict Major Heat Wave

Start getting ready to hear the heat wave classics on the radio ... according to virtually all weather forecasters in the Twin Cities, a major heat wave is expected to arrive by the end of the week. For Sunday, no forecaster is going lower than 95. At this point, KSTP is most bullish on a persistent heat wave, forecasting a high of 98 next Tuesday. As of Tuesday evening, here's how both the local and national weather outlets saw the steamy forecast (Strib forecast is as of Tuesday morning):


Update: As of Wednesday night, here's how forecasters saw the upcoming heat wave (Saturday through Wednesday). Note that KSTP, as it often seems to be, forecasts the highest temperatures, with an average heat wave temperature of 97.4 for the five-day period.