Winter Storm Coming
A WINTER STORM WARNING IS IN EFFECT STARTING 6:00 AM THRU NOON ON MONDAY FOR THE METROPLEX AND MOST OF NORTH TEXAS.
This is our first winter weather event of the season and it continues to look like a significant event in regards to our roads. As any winter event of this type, there is an uncomfortable margin of uncertainty on where sleet will fall and where freezing rain will occur. Many areas will have both. Here’s the headlines:
THE DOUBLE PUNCH
Old Man Winter delivers a classic (for the southern plains at least) double punch of weather. The left cross if you will is a second surge of cold air currently making its way into north Texas. This is courtesy of a dome of high pressure moving from the Dakota’s into the Ohio Valley tomorrow.
Not only does it sweep away the meager warm-up we had this afternoon (officially at DFW Airport at high of 43°: the typical LOW this time of year) but this shot of cold air is also extremely dry. We expect dewpoints to drop from the 30′s right now down to the upper-teens by morning tomorrow. More on that in a moment.
The right upper cut is the powerful upper-level low that will move right over the top of this pool of cold air:
This will be snow for Childress and to the west and up into the Panhandle. For us it will be sleet and freezing rain with some snow falling across our northwest and Red River counties. The western counties of Comanche, Eastland, Stephens and Young will start getting frozen rain/sleet in the morning. It’ll be moving east as the day continues.
Dry air started moving in overnight from the north as dewpoints dropped down to the teens. This dry air is the fly in ointment in regards to our forecast.
For the metroplex, the first wave of precipitation will come in around noon. Temperatures started around freezing this morning and will warm to the mid-30′s by mid-day. As this precipitation moves overhead it’ll start dropping the temperatures as the winds start swirling around a bit. What’s happening is that the precipitation that is falling (snow and ice above the ground) is evaporating. This of course is a cooling process (that wind is the colder air falling down to the surface). As the air column starts to cool the rain quickly changes over to sleet. Temperatures will drop a few degrees over the metroplex, hopefully staying at or just above freezing the rest of the afternoon and evening. THIS MEANS SLEET NOT FREEZING RAIN FOR THE METRO. THE FREEZING RAIN THREAT WILL BE OVER OUR WESTERN COUNTIES FROM COMANCHE UP TO MINERAL WELLS TO BOWIE. This is only the first wave. The forecast models don’t handle this evaporational cooling very well. A few degrees of extra cooling could make this a major ice storm (with snow) for the metro area.
Overnight another, heavier round of winter weather moves in. The air column is not going to warm any of course, there is almost 14 hours of nighttime so they’ll continue to drop. This round starts as sleet for the metroplex. The area of freezing rain will be larger in the second round but mostly just to the west of Fort Worth up Hwy 199 to Decatur. Mineral Wells to Gainesville might have a significant icing event from this wave as some snow will also be in the mix. The metro area will likely see heavy sleet with occasional freezing rain. This will go on all night into Monday morning. In summary, here is the winter threat:
Here is a sequence of snapshots of the weather from our FutureSky forecast. By noon the first wave of winter weather will be arriving into the metro area. It will go on the rest of the afternoon. Just to the west and north of the pink line (freezing or below at the surface) is where the threat of freezing rain is the highest. If the evaporational cooling is greater that freezing line will be south of the metro area and an icing event will be in progress. Fingers crossed!
This wave will move out by evening. There will be a short break in the action. Notice temperatures try to inch up a little. The next, heavier winter precip. arrives just after midnight:
Keep in mind that the green that you see on Monday morning will mostly be sleet; this is the forecast model not handling the atmosphere cooling very well and having us too warm. I think we’ll actually be in the upper 20′s on Monday morning so freezing on the road surfaces will be going on in earnest. This will be the peak of the HAZARDOUS ROAD CONDITIONS:
This will go on most of the morning before moving to the east. It’ll likely end as a little bit of rain:
One of the other things that is changing in the forecast is the movement of the upper level low. Most of the models are moving it deeper south and moving it slower. As it passes over us it’ll wrap around some cold air and winter weather. We are putting in a higher chance of precipitation on Tuesday. This time the odds are good this is mostly snow, especially in our eastern counties. There could be some minor accumulation from Greenville down to Corsicana and east.
This will be another thing we’ll be watching. If the forecast models continue the trend of making the backside of this upper-level low more of a player we could end up with a surprise snow in the metroplex on Tuesday.
The good news in the forecast is the nice warm-up in store after all of this. For Thanksgiving we should be in the mid-50′s. Next weekend back into the 60′s: