Winter 2010-11 for the Southern Plains

[somethingfunny]

I'll mark my calendar. October 18!

Sorely disappointed.

[Extremeweatherguy]

As expected, the snowy model solutions for the southern plains to end the month have disappeared. However, the latest run of the GFS does continue to indicate a big (and welcomed) pattern change on the way starting in about 6-7 days. Beginning early next week it shifts us into a much more active front pattern, with several stronger cold fronts moving into the area through the end of the month and into November. If this pattern does indeed pan out, then it might finally begin to feel more like mid-autumn, and frost and freeze threats into northern parts of the southern plains (Oklahoma, N. Texas) could be possible in the day 7 to 16 range.

The 00z ECMWF also seems to agree with this pattern change idea, sending a large trough into the central and eastern United States between October 27th and 29th.

Update: The 12z ECMWF now has the trough centered more over the western/central United States by the end of the month, with a strong front pushing down the plains and into our region (OK/TX) by October 28th/29th.

[Extremeweatherguy]

Today's GFS and ECMWF runs continue to be supportive of a shift to a cooler weather pattern starting mid/late next week.

Below is a look at both model's depictions of the first in a series of decent troughs to move into the region during the late October/early November time period (assuming the general idea from the guidance holds). This one in particular is depicted as arriving in 7-8 days, and while some changes are still likely, the models are surprisingly in fantastic agreement right now:

GFS (12z)

168 hrs - Wed 10/27


192 hrs - Thurs 10/28


216 hrs - Fri 10/29



ECMWF (12z)

168 hrs - Wed 10/27


192 hrs - Thurs 10/28


216 hrs - Fri 10/29

[Ntxw]

^ I think it's not totally out of the question that much of Oklahoma could be experiencing the first widespread freeze at the end of this month and early Nov. Until then looks like warm/somewhat humid north and warmer humid south conditions should continue per GFS/EC.

[Extremeweatherguy]

Well unfortunately both the GFS and ECMWF have backed off on the intensity of the cold airmass arriving later next week, now just showing a weak/moderate late October cold front. If the models don't start trending colder again over the next few days, then it looks like we might have to wait a little while longer before we see our first widespread freeze threat across the southern plains.

[amawea]

Well unfortunately both the GFS and ECMWF have backed off on the intensity of the cold airmass arriving later next week, now just showing a weak/moderate late October cold front. If the models don't start trending colder again over the next few days, then it looks like we might have to wait a little while longer before we see our first widespread freeze threat across the southern plains.
Well unfortunately both the GFS and ECMWF have backed off on the intensity of the cold airmass arriving later next week, now just showing a weak/moderate late October cold front. If the models don't start trending colder again over the next few days, then it looks like we might have to wait a little while longer before we see our first widespread freeze threat across the southern plains.

Yep Extremeweatherguy, the discussion out of Springfield, Mo. actually talks about a slight warm up at the end of next week. Two days ago they were talking a freeze.

[Extremeweatherguy]

The 12z and 18z GFS and the 12z ECMWF have trended back slightly cooler today for the late week front. Still not as cold as it once looked, but at least the warming trend in the models seems to have ended for now. All in all, this is shaping up to be a moderate October front. Enough to knock temperatures to near or slightly below normal for a few days, but nothing unusual or overly cold (compared to averages). Could see a frost threat for areas north of Red River if a night of good radiational cooling develops, but for late October such a scenario is not really too uncommon.

[Extremeweatherguy]

[TwisterFanatic]

Watching the weather today and they said possibly major cold blast next Tuesday or Wednesday. Highs might not get into the 50's.

[Extremeweatherguy]

Watching the weather today and they said possibly major cold blast next Tuesday or Wednesday. Highs might not get into the 50's.

There are some indications of a more significant cold shot next week, but details are still not tied down on exactly how/when (or even if) it will play out. The ECMWF, for instance, brings down a moderate shot of cold early in the week ( http://i43.photobucket.com/albums/e371/ ... PUS144.gif ), followed by a much stronger shot of cold for the eastern 1/2 of the USA by the end of the week ( http://i43.photobucket.com/albums/e371/ ... PUS216.gif ). The brunt of this later cold wave is centered more to our east, but if the ECMWF depiction of the surface high settling right over Oklahoma is correct ( http://i43.photobucket.com/albums/e371/ ... PUS240.gif ), then the first widespread freeze/hard freeze of the season could be possible across the area under favorable nighttime radiational cooling conditions.

The (18z) GFS looks warmer than the ECMWF, showing fairly mild conditions across most of the country during the same period that the ECMWF looks chilly. If it is correct, then temperatures would be much closer to average late next week.

Update - Unfortunately, the 00z ECMWF has trended warmer for late next week.

[Extremeweatherguy]

We're expecting the coldest morning so far this season here in the OKC vicinity tomorrow morning. The forecast is currently calling for mid 30s around the area with frost likely, which would beat the previous coldest reading of 37F experienced earlier in the month.

[Extremeweatherguy]

Today's 12z run of the ECMWF is back to a very chilly look for mid to late next week. In fact, for the southern plains in particular, this is the coldest run we have seen so far. If something like what is depicted actually plays out, then we could easily be looking a period of below normal temperatures to end next week, with a widespread freeze threat (several degrees colder than tonight) for the northern half of the southern plains.

ECMWF 850mb temperature/sea-level pressure maps for mid/late next week:

WED MORNING (144 hrs)


THURS MORNING (168 hrs)


FRI MORNING (192 hrs)


SAT MORNING (216 hrs)


Well the ECMWF keeps going back and forth. The 00z run is back to showing most of the cold air heading to our east.

[NY NJ PA Weather]

The models are having problems because of the convection around 180 to 160E, this is causing issues with the various long range models handling the position of the ridge around the Aleutian Islands and thus the changes from run to run on the models. Also, an interesting note is the problem the models are having with forecasting the MJO phases. One goes into PHASE 5, the other PHASE 7/8 which are two completely different patterns.

The key is that convection. The little things DO matter. BTW, snow cover growth is rapidly building over NH, big key indicator for Arctic Air Masses for late November on.

[amawea]

I had 26.8 on my digital weather station here in the boonies of North Arkansas this a.m.

[CaptinCrunch]

I had 26.8 on my digital weather station here in the boonies of North Arkansas this a.m.

36 this morning at the house in rural Tarrant Co. even had a light frost on the rooftops.

[TwisterFanatic]

Had a killing freeze this morning. 24 degrees.

[Texas Snowman]

Upper 30s here in Grayson County. Light frost on the rooftops. Gosh I hope it was enough to end the ragweed season here!

[Extremeweatherguy]

Low temperatures this morning across Oklahoma:



Coldest night of the season so far in my location (33-36F). Enough for frost to cover the cars around sunrise.

[Ntxw]

Today's EC and GFS says BRR next weekend for the southern plains and deep south. 40s for highs anyone?

[Extremeweatherguy]

The 12z ECMWF run is definitely pretty chilly, and while the GFS is a bit warmer; it too has trended colder recently. I like the idea of a decent cold airmass coming into the nation next week, with the brunt staying to our east, but with a nice taste down the plains. The ECMWF scenario actually looks quite possible, IMO. If such a scenario actually plays out, with the 0C 850mb line dipping all the way to the Gulf Coast, then many from central TX and OK eastward could be in for their coldest readings of the season (so far) by late next week.

I have posted the 12z ECMWF run below for those interested:

Hour 96 - 168 of the 12z ECMWF run (SLP/850mb Temps):

WED MORNING (96 HRS)


THUR MORNING (120 HRS)


FRI MORNING (144 HRS)


SAT MORNING (168 HRS)