Saturday, June 18, 2011

A Case of Dew Point Inflation?

There have been occasions this spring/summer where a few forecasters have rather casually tossed around 70-degree dewpoints, the levels at which most agree things feel pretty steamy and tropical. The skeptic in us thinks that exaggerated dew point temperatures are used to grab attention in the same way that exaggerated wind chill temperatures are used in the winter. Today seems to be one of those days.

This morning's blog from the Star Tribune states that today's (Saturday's) dew points will be in the tropical 70s per below:


However, dew point forecasts obtained from Weather Underground and sourced from the National Digital Forecast Database (NWS) predict dew points will go no higher than 65 today:


In the world of dew points, a dew point difference of five or more degrees from 65 to 70+ is significant. It's the difference between "rather muggy" and "really muggy/oppressive."

14 comments:

  1. You usually don't see Tds in the 70s that far north until July/August when the evirotranspiration really kicks into gear as crops reach maturity across the plains and moisture advection from the Gulf of Mexico reaches a seasonal peak.

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  2. Bill anyway you slice it dew points above 60 suck,who likes to be muggy unless your sitting on a beach with a cold one,and PD wasn't far off current dew points at this time is 67 at MSP and 70 at Flying cloud(Eden Prairie)

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  3. Bill I have to agree with big daddy,dew points in the 60's are uncomfortable,when you hit 70 its tropical,to bear it sit in AC till the north winds blow.

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  4. Bill to answer you question on the previous thread...CWA = County Warned Area, and is the area that each of the nws office's are responsible for

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  5. Where the heck is the sun???!?!?!?! I can't believe how crappy this spring, and now summer is - my friend recently called it "sprummer". All the forecasts had "clearing skies, a sunny Father's Day, and high in the low 80's." I haven't seen a ray of sun and it is 4:22 pm, another wasted weekend day. The boaters and outdoors people have had it - how about an old fashioned sunny and hot summer weekend? This weather pattern is getting really old and it seems the forecasting is equally as bad lately, time after time it not doing anything like what is forecast. And now I see that there are a few 60's forecast for HIGHS? in late June? La Nina can go to ****, that or whatever it is that is causing the absent of heat can equally and likewise hit the road to Hades. I'd take dew points in the 60's and 70's and temperatures in the 80's and 90's any day, absolutely any day over this depressing cloudy cool garbage. We wait all year here for a nice spring and summer, sometimes an occasional nice fall, and two years running, this is what we get. It is time for a change.

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  6. Hmmm Anon: Seems to me we had a warm very humid summer last year with dew points being up, that caused the greatest severe out break last year on record, give me 75-80° temps, with mid 50's dew points any day...as a mater of fact I would take 85° if the DP's we in the mid 50's

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  7. BTW that reminds me...keep a heads up tomorrow, things could get interesting south of the metro.

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  8. Feel your pain Anom. That flashy 103 may end up being summer.

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  9. On the day it was 103, I actually told people, "Enjoy it. This is probably your summer." We had 7 months in a row with snow, and that snow was on the ground solidly for over 4 of those months of those months. That was followed by a cloudy, cold, rainy spring, which is being followed by an equally cloudy, cold, rainy summer...sans two days above 90. This is what we get for spring coming on March 1st in 2010.

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  10. Obviously weather doesnt make everyone happy and cant please everyone(i.e. Anonymous from 6/19 4:27),but if there is a perticular weather your after Minnesota is not the state to be in,because its constantly changing,doesnt stay the same for awhile,thats why I say move to San Diego if you want boring or Texas if you want warmth or dew points,Randyinchamplin I couldnt agree more 70's for highs and 50's for dew points is perfect summer day,maybe 80s if no humidity or if your near a body of water. BTW....SOME HEAVY RAINS COMING!

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  11. for those of you that want heat, it appears to be on it's way, I know Paul Douglas showed the ECMWF on his blog for today, looking for confirmation of a warming trend I looked at the GFS ensembles for the next 15 days. I want to point out Jul 1st. The large map is the mean ensemble the smaller maps are each ensemble member, on the lst there is one ensemble member that shows us -6 to -9 from normal, and one that is pretty much normal, all the rest are well above normal. I think we may see a day or two around that time of +9 to +12 temps above normal, so it really does look like a warming trend is in the future.

    Map is provided courtesy Of the Penn State University e-Wall site.

    http://www.meteo.psu.edu/~gadomski/ENSTDEP2_6z/tloop.html

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  12. Anyone want to give me their best forecast for Wisconsin Dells for this Monday(6/27),going there with the kids,need some great weather,I've heard/seen anywhere from sunny skies to thunderstorms the last 3 days of looking. Thanks!

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  13. Big Daddy: it looks a bit unsettled to me

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  14. Another nice, sunny weekend they predicted huh? It was CLOUDY when I got up this morning and now it's RAINING. Unbelievable...

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