It was hard not to notice that the NWS office of the Twin Cities stood tall with the issuance of an Excessive Heat Watch some 60 hours before the time it went into effect. On Monday evening, the NWS advised us that excessive heat levels might be reached during the day on Thursday. It may not have been an unprecedented amount of warning, but it’s not something we don’t see often. One would guess that the issuance of a watch so far in advance would suggest the likelihood of serious heat, but that does not appear to be the case based on the “regular” hot forecast in effect as of this writing (6 p.m. Wednesday)
Something seemed amiss about this watch from the start. When the watch went into effect the only counties within many miles (five states perhaps) of the Twin Cities were Hennepin and Ramsey. This suggested it was a marginal at best. And even while the forecast temps at that point were close to 100, the dew point forecast did not go above 60—hardly oppressive.
We understand that a watch does not always mean a warning will follow. But for the NWS to trumpet the heat watch so many hours in advance suggested a certainty and confidence that didn’t bear out. In the end, the NWS/Twin Cites looks a little silly.
Good write-up. Thursday's forecast high is now 91, which would be not even as warm as today.ReplyDelete
I've noticed that, with the exception of those few days in early July, very few of these ultra high temps predicted this summer have panned out. I think it's partly because they apparently cannot predict cloud cover to save their lives. But there must be other reasons why we still can't accurately forecast something as basic as temperature a few days in advance.
I can agree with you on the cloud cover. I like astronomy and have lost count of how many times the models (particularly the Canadian) have said a clear night only for it to be cloudy.Delete
Sadly Isaac is an example of the overuse of the Saffir-Simpson scale by people. But its only a category 1, I'm not going to evacuate even though I'm in a flood prone area.ReplyDelete
Yep. Very few lay people (including most of the media) took into account that Isaac was an extremely slow-moving storm. It doesn't need 180 mph winds to destroy things. All it needs to do is sit over New Orleans and there'll be floods.Delete
Forecast high is 95 today but low dew points as you note will keep things below criteria level, however, it will still feel mighty warm especially those at the State Fair walking around the concrete/tar streets where temps will be another several degrees warmer. Hopefully, folks will be hydrating with water (not just pop and beer) as they tool around and eat all the great food! Wish I were there!ReplyDelete
Meteorological Note: The dry air across the Central Plains from the long-lasting drought has made for fairly bearable weather for heat-index (i.e. "feels like")since the antecedent moisture in the ground is so low thus air that advects from the SSW to Minnesota is drier than normally would be this time of year. Models don't always handle this best and can make forecasts tough including the Excessive Heat Watch issued the other day. Conditions began to show that drier air was going to be king and that allowed NWS forecasters to drop the watch and not need a warning or advisory, but to still promote hot temperatures. A blowtorch day, as they call it in the Plains ahead of a cold front, as temperatures will shoot up sometimes exceeding forecast guidance as compressional warming takes place just ahead of the front moving in. A little bit of that today.
Not as silly as a blog that only features posts complaining about a forecast without making ANY effort to understand it or the process.ReplyDelete
Clearly the focus was the Twin Cities Metro area and the urban heat island. As your commenters have posted previously, concrete and air conditioning contribute to warmer temperatures and more dangerous conditions within metropolitan areas than without. To me, it seems that the forecasters were intent on highlighting a potential threat in a period that is generally perceived as being "after" the main heat threat period, late July and early August. The excessive heat watch may have been warranted based on the forecast trends and mid-range guidance on Monday and Tuesday. By Wednesday the guidance began to indicate the passage of a cool front before max afternoon temps could be reached, thus diminishing the threat.ReplyDelete
Bill, your posts on this topic are often an attempt to belittle forecasters rather than an attempt to either "understand the forecast" or "rate forecasters". I, for one, expect a bit more, especially given the thoughtful comments you receive from most of your posters. Isn't it time to start putting more effort into your posts, or are you merely interested in criticizing something you don't understand?
The only thing that is silly is me for coming to this website thinking it was legit and had credibility.ReplyDelete
Well, they've big-time expanded the SLGT area on the convective outlook, though not the tornado risk area. The western boundary moved way west to cover most of MN and IA.ReplyDelete
Will there be another big bust like the last two times we've been in SLGT? I would be surprised to see one drop of rain the way this summer has gone.
1st off all I was surprised when I saw the afternoon update, I didn't see much guidance showing the change before I left for work this morning at 10am.Delete
Now another drastic change and they have taken the metro out of the slight risk area.
Dew points over the Metro dropped from 62 to 53 between 2 and 3pm. Observed sounding from MPX at 7pm showed zero instability.
The Nam 05/0z run shows the low level jet setting up just se of the metro, thus I don't think that will bring in any instability thru the early morning hours. It also shows some rain is possible over the metro, less than .25", However from 5000ft down it also shows the relative humidity to be quite low,(ie dry).
Therefore expect the heaviest rain south and east of the Metro, far southern metro could see some. For those in the north metro, chances for a dry night look good at this time. And based on the 04/12z run of the ECMWF, this was our best chance of beneficial rains.
Yeah I know, up here in Champlin it is very dry.
NAM is interesting for Saturday morning. Shows lower to mid 30s over central MN.ReplyDelete
Interesting that a remenent piece of Issac has dropped back into the gulf. Of course, it would be named different because it was not part of the original circulation, but it is unusual for that to occur. The system could be dubbed as "the ghost of Issac". Whatever happens, I wish good luck to the folks down south.ReplyDelete
Here's an excerpt from Jeff Master's blog regarding the hurricane naming convention for remnants:ReplyDelete
According to NHC naming rules, "if the remnant of a tropical cyclone redevelops into a tropical cyclone, it is assigned its original number or name". Since "the remnant" refers to the primary remnant, and 90L does not fit the definition of a "primary remnant", the storm will be given a new name should it develop into a tropical storm, according to information posted on the NHC Facebook page. Esau or Jacob--the names of the sons of the biblical Isaac--would be fitting names for 90L, but the next storm on the list of Atlantic storms is Nadine.
It won't due much besides develop into a sheared tropical storm. If you look at the water vapor loop you can see an upper level low near the Bahamas putting some strong shear on it. Once that shear dies down, it will have a short window to develop before the cold front that we just experienced kicks it NE.ReplyDelete
On a side note. The GFS has been fixed and is now handling the drought much better.ReplyDelete
Last May it got a upgrade to do a better job with forecasting hurricane tracks, however it caused the above mentioned problem.
Here is the link.
I'm sure our local mets will love this fix. As a matter of fact the weekend of 8/15 looks blow torch warm with both the Euro and the GFS hinting at temps close to 90° It's a long ways out but at least now their is some agreement.
@Randyinchamplin I think you meant to say 9/15(not 8/15)also accuweather(our favorite website to hate)after your said blowtorch weekend has us going the opposite direction with several days in a row of 50's and even upper 30's for lows,any truth to that Randy......would love to see some cool weather moving in just in time for fall and football and tailgating weather.ReplyDelete
modeling is now showing the ridge getting flattened next week which will put us into a zonal flow for Sat and Sun we may just see a nw flow, but the source region is fairly warm. Looks more like a weekend of near normal high temps.Delete
Wunderground is predicting 95 for Tuesday. What a joke. On the other hand, my favorite weather actress (Belinda Jensen) was damn sure we wouldn't make it out of the 60s today. It's 70 right now.ReplyDelete
FOX 9: 87
CBS shows 89 as I look at it right now (4:10 p.m. on Friday). I also do see 95 for wunderground (their BestForecat). I haven't checked the others. Might try to do a recap later on.Delete
If it was a joke, Weather Underground is nailing today's heat. Props to them.Delete
Seems like temps all week have been higher than forecast...ReplyDelete
Yeah. As rough as the forecasting has been lately, I wouldn't be surprised to see snow or 115 on Tuesday :)Delete
For amusement purposes, I just posted the Tuesday predicted high temps in an updated post. Go summer!ReplyDelete