Gary McManus joined the Oklahoma Climatological Survey in May 1999 and currently serves as the State Climatologist for Oklahoma.
It’s Thanksgiving Week (you’re welcome for the reminder), so that means lots of folks will be traveling here and yonder for Thanksgiving dinner, traveling even faster away from said Thanksgiving dinner when they’ve had enough of Uncle Ed’s jokes, or even waiting in long lines for that Black Friday (Thursday night) deal. So obviously the weather forecast for this week is important. We’re still several days out, so the forecast is STILLLL a bit iffy here and there on specific details, but there are a few things that appear to be a sure bit (if still a bit fuzzy).
1. It’s going to rain, and probably a lot, starting in some locations on Wednesday night, especially into Thanksgiving, and then over the next several days in coughs and fits.
2. It’s going to get cold thanks to a strong cold (duh!) front on Thanksgiving night.
3. With the presence of the chance for precipitation (remember, the coughs and fits and whatnot) and the presence of cold air, it appears there will be a chance of some period of wintry precipitation over the weekend, in fact starting late Thursday night up in the northwest part of Oklahoma.
First, the moisture amounts associated with this system will be tremendous. The atmosphere appears primed to go nuts on us. The National Weather Service (NWS) Norman Office’s forecast discussion on Sunday afternoon had this little gem to spring on us (I’m going to paraphrase the forecaster here a bit to make it a bit more digestible):
“PRECIPITABLE WATER AMOUNTS (the amount of water vapor in the air available to be turned into precip, basically) FROM THE GFS (a forecast model) of around 1.7 INCHES! FOR THUR SUGGEST AN INCREDIBLY MOIST ATMOSPHERE WILL BE IN PLACE. THIS AMOUNT WOULD BE ~0.2 INCHES ABOVE THE HIGHEST EVER RECORDED DURING THE MONTH OF NOV FROM AROUND 1950 TO PRESENT BASED ON SOUNDING CLIMATOLOGY FROM SPC.”
Well that’s not good, unless you’re taking a boat to Grandma’s house. The 7-day precipitation forecast is off the charts for this time of the year. Again, notice the southeast bias towards higher precipitation amounts in the image below.
Holy cranberry sauce but that’s a lot of water for November! The 3-4 inch amounts extend all the way up into northwest Oklahoma. Here are a few graphics detailing what the local NWS offices that cover our state think of the holiday forecast, with complete understanding and transparency that this can and probably will change to some degree as we go through the week. In fact, it will probably change during the event itself, so be sure to stay advised of the weather if you’re traveling at all.
Notice the mention of flooding, then some slick travel concerns. The key here is the location of the cold air coincident at the time of the precipitation, and right now the forecast models just don’t have a complete consensus right now. We showed this on our Facebook page yesterday, but it’s worth showing again today. It comes from the NWS office in Ft. Worth, and it shows the difficulty of making a forecast when the models don’t show much agreement.
And the NWS Norman forecast discussion from on Monday morning says the same thing, but in words:
“...SITUATIONS LIKE THIS ARE VERY FLUID AND CONFIDENCE IS STILL NOT HIGH THAT MODELS ARE HANDLING THE EVOLUTION OF THE UPPER LOW AND LOW LEVEL THERMAL FIELDS WELL.”
All that means that you need to stay tuned to the weather on a day-to-day and even hourly basis if you’re going to be traveling because it doesn’t take a lot of ice to cause a lot of problems.
RIGHT NOW, it looks like we’ll get warm enough each day for things to stay liquid during the most important travel times, but also it appears each night has the capability to get cold enough to cause some icing. Again, I turn to the NWS Norman Office for some elucidation.
RIGHT NOW this doesn’t look like a serious winter event for most of the state, but it could be a bit more serious across the northwest part of the state. And again, that could expand to the southeast depending on the temperature profiles of the atmosphere. Remember points 1-3 above which are pretty high on the confidence level right now: it’s going to rain (a lot), it’s going to get cold, and there will be some frozen precipitation that could impact travel somewhere in the state late Thursday into the weekend.
In light of that, here is a preliminary BRAUM’S EMERGENCY BREAD AND MILK DEF-CON map for the state for Thursday night into Saturday. Very preliminary, very much geared to daytime travel risks. If you’re out at 3 a.m. making a run to Braum’s, you’re not only in for some possibly risky travel conditions, but a long wait until Braum’s opens!
Will we update this DEF-BRAUMS Map? Ask the atmosphere. If you get an answer, let us know!