Showing posts with label Chris Shaffer. Show all posts
Showing posts with label Chris Shaffer. Show all posts

Tuesday, January 14, 2014

Grading Jan. 13-14 Storm (and what was Chris Shaffer thinking?)

It’s been a while since we’ve graded forecasters. In truth that’s because there hasn’t been much interesting weather (i.e., snowstorms) and because there’s been little forecaster variance. This time, however, we feel compelled to highlight the particularly poor forecast by WCCO’s Chris Shaffer.

Here’s an excerpt from Shaffer’s forecast on the 6 p.m. news last night on WCCO. He said that “most of us will see less than an inch.” He went against all others and consistent model data. It seems he looked at one rogue model solution and ran with it. With the 4.4” of snow that fell, we think that most viewers would call this a poor forecast.

Chris Shaffer forecast from 6 p.m. WCCO newscast.

While a bad forecast is one thing, coming out 24 hours later and implying it was just what you expected is harder to swallow. Here’s a video capture from a segment of his 6 p.m. weathercast from Tuesday night. There’s the clear implication that the storm was what he expected (“just a little snow) yet he actually brings forth reported totals that are in excess of the totals he’s trying to validate. And how can he continue to call this “not much snow” when it caused snow emergencies in both major metropolitan cities? The fact is that we received one of the biggest snowfalls of the season with 4.4” and much of the metro received 3-5”. That’s a solid snowstorm in most peoples’ books.

Not surprisingly, we have to give Chris Shaffer’s forecast an F. Here are our grades for the efforts of other local forecasters:

WCCO: F. A poor forecast and an even poorer follow-up self assessment.
KSTP: B. More aggressive than most with a 2-4” forecast, but not aggressive enough. Also emphasized 2-3" with "spots seeing 4".
KMSP: C. Too conservative at 1-3 inches.
KARE: C. Same as KMSP
NWS: B+. They were consistent in forecasting 2-4” and, appropriately, issued an advisory.
Strib: C. Todd Nelson’s 1-3” forecast was too conservative.
MPR: C. While noting forecast volatility, was too conservative at 1-3”
Novak Weather: A. Refer to this video (beginning at 11:45).

Wednesday, June 1, 2011

Forecasters Foresee Friday Firecracker

On this first day of meteorological summer (June 1), mother nature seems poised to produce the hottest day of the year thus far on Friday. Here's the forecast high for the various weathercasters in the Twin Cities as of 7 p.m. on Wednesday.

WCCO: 89*
KSTP: 92
Fox: 91
KARE: 88
NWS: 90
Strib: 90 (mid-day update)

*On the 6 p.m. forecast, WCCO's Chris Shaffer chose to show the forecast temperatures estimated by "one of the models." The model, presumably the one that showed the hottest temperatures, depicted a temperature of 94 for the Twin Cities, but, Shaffer added, "I don't think it'll get that warm." Our question is simply this: Why show a model with a temperature that's a full five degrees greater than what you are forecasting? WCCO has done a similar thing with snowfall forecasts in the winter. It seemed irresponsible then and it seems irresponsible now.

Chris Shaffer provides a visual of one model's forecast high temperatures.

Enjoy the heat, as at least one major national weather provider is forecasting a cooler than normal summer. Here's Accuweather's forecast for summer temperatures:

Wednesday, March 23, 2011

Grades for the (Mostly) Unwanted Storm of March 22-23


Our standard disclaimer: The grades we provide are not scientific. However, they represent our best effort to assess the performance of Twin City weather outlets. Our grades are based on established grading criteria and we maintain forecast histories for each event. It might also be helpful to read our “Weather Watcher’s Bill of Rights” to get a sense of our perspective.

Over the last several weeks, it seems, the ferocity of a storm seems inversely related to the amount of media hype. This storm was no exception. For the progressive forecast by weather outlet for this storm, click here.

In general, the rain/sleet/snowstorm of March 22-23 was tough to forecast. Until about 12 hours before the onset of the storm, most forecasters believed the heaviest snow would fall well north of the Twin Cities and that the storm’s calling card would be a small, slushy nuisance accumulation. In the end, the inner core of the Twin Cities was significantly affected as evidenced by the huge number of accidents reported (although the highest amounts of snow did fall just north of the central cities).

The late change in the storm’s track clearly had forecasters scrambling and ensured that a top grade was not attainable (except in one case). In addition, it seemed that some forecasters embraced late model changes while others seemed to discount them.

Here are the grades for what many hope will be the last significant snow of the season:

WCCO: C+ From a presentation standpoint, we have issues with WCCO’s visual depiction of what a certain model says when the forecaster goes on to say he doesn’t believe it and that it just provides an idea. The fact is that television news is all about visuals and we think that if people see 6.9” printed out for the metro and 18” totals for parts of northern Minnesota that that’s what they’re going to take home with them. We think that viewers are far better served by the meteorologist creating a fresh, non-model produced graphic that reflects what he/she thinks will really happen. OK, off our soapbox. TMF readers, do you agree? Beyond the presentation matter, WCCO did pick up on the final twists and turns of the storm, correctly predicting 4-6 inches as of the 10 p.m. newscast. However, as with most other prognosticators, they underestimated the magnitude of the storm in the days leading up to the event.

KSTP: A- This was a very good performance by KSTP. They were the first to latch on to the possibility of more than 1-3 inches of snow (on Monday night) and they were steady in their predictions from that point on. And, they were generally accurate with predictions of 3-5 inches of snow for the south metro and 6-10 inches on the north side. Our one complaint with KSTP was that they dropped the use of their confidence ratings, a tool we thought would have served viewers particularly well in this storm, particularly given the high uncertainty of the timing of the changeover to snow.

FOX: B- FOX was generally in the middle of the pack on this one. They were in the 1-3” boat like most others until the final bell, when their final forecast was for 3-5 inches. To their credit, FOX made a clear and unequivocable case for the bad road conditions that would greet commuters in the morning.

KARE: D It’s always a little hard to assess KARE given the cautious way they state their predictions, but it seems pretty evident they never got a good handle on this storm. On Friday evening, when all other weathercasters were allowing for the possibility of accumulating snow, KARE said it was “looking like mostly rain Tuesday night into Wednesday.” On Tuesday’s evening, KARE predicted 1-3 inches, a prediction they stayed with through Wednesday night’s 10 p.m. forecast, a time at which virtually all other outlets predicted higher, and more accurate, amounts. It seemed to us that KARE was asleep at the wheel.

Star Tribune: B The interesting situation with the Strib column this past week was that the regular blogger was on vacation during much of the time the storm was evolving, leaving one to wonder what might have otherwise been predicted in the days preceding of the storm. Nonetheless, the Strib’s blog was generally in the weather forecaster mainstream until yesterday evening, when readers were put on alert that there was an unmistakable change occurring. We give credit to the Strib for putting out the timeliest update (6:30 p.m.) of the important forecast change, one that seemed to turn the storm from a nuisance storm to something with considerably greater impact. The updated snow estimate of 4-8 inches was generally on target.

MPR: B- As we’ve mentioned before, evaluations of MPR must take into consideration that for the most part it’s a one-man operation. It also emphasizes statewide weather given the nature of its readers and listeners. So we’re never sure whether to include it with our grading. That said, MPR blended with most other weather outlets for this storm. We applaud the alert as to the general escalation of snow totals; however, it was issued at 11:10 p.m., likely a little late for most people to plan accordingly.

NWS: B+ It’s challenging to assign a grade for the NWS this time around. The weather discussions and early forecasts suggested that the storm would be more than a nuisance. They called for a 70 percent chance of snow as early as Friday evening and included accumulation totals of one sort or another from that time forward. This was all good. However, they were late in issuing warnings and advisories. And the eventual declaration of a Winter Storm Warning when there was never a prior Winter Storm Watch can’t be the way they draw things up at the NWS. Then again other media outlets aren’t burdened with the duty to declare watches and warnings.

Agree or disagree with our forecaster grades? Let us know what you think (that includes our beloved forecasters whose performance we judge).