This roller coaster of a winter shows no signs of letting up as we head through the opening days of 2017. We have sleet, wind chills in the teens, a widespread freeze…and 80° weather to discuss. Here’s how it will unfold.
Friday & Weekend
Cold weather has now settled into the region.
6 AM temperatures are cold enough for perhaps some sleet or ice pellets to mix in, mainly north of Houston. (NOAA)
Expect a chilly, raw day today. We’ll have a stiff north wind, coupled with temperatures not getting much warmer than they are on the map above. In addition, we’ll have clouds and occasional light rain and drizzle throughout the day. Temperatures will be cold enough for perhaps some sleet or ice pellets to mix in over the area. Fortunately, the precipitation looks light enough and temperatures just warm enough that this shouldn’t be anything more than “conversational” wintry precipitation.
HRRR model forecast radar for today shows potential for some sleet to mix in at times, but probably no travel problems or ice accumulation. (Weather Bell)
But don’t be shocked to see or hear some ice pellet pings today.We’ll clear skies out, and actually, the weekend is going to be an absolutely beautiful winter one for Southeast Texas.
Oh, my fellow runners, if you want to be depressed then take a look at the GFS ensembles that came out this afternoon. I’ve annotated the forecast, which takes into accout about 50 different runs of the GFS model based upon observed conditions this morning.
GFS ensemble model forecast. (Weather Bell/Space City Weather)
What’s depressing is that the range of lows forecast by the GFS model for Sunday morning, January 15th, runs from about 63 to 73 degrees, and the corresponding dewpoints are nearly as high, meaning we’d be looking at a humid race day too. This is about the worst-case scenario, barring fire-and-brimstone-type thunderstorms with tornadoes thrown in.
Good morning. Temperatures have generally fallen into the upper 40s to low 50s across Houston this morning, and this is actually quite warm compared to what is ahead, as it will get downright cold this weekend, with a real winter feel.
Today
We should see highs around 60 degrees today as winds return from the south. Skies will probably remain overcast most of the day, and there’s a chance of some light, misty rain later this afternoon and evening, especially along the coast. Winds will shift back out of the north tonight, marking the beginning of a really cold three-day period for the region as cold air moving in will drive lows on Friday morning into the low 40s.
Friday
Cold. Gray. Gloomy. Possibly some light rain. All this and more describes conditions on Friday, when highs will struggle to rise out of the low 40s. Oh, and there will be a stiff northerly breeze that will add an additional burst of cold. You wanted winter in Houston? You got it.
Temperatures on Friday night will fall likely fall just below freezing in the city of Houston, and likely into the upper 20s north of the city. While that would be cold enough to produce some frozen precipitation, it looks like any rain chances will end by Friday evening, which means the region shouldn’t see sleet or any other type of wintry mix to complicate driving conditions.
Estimated freeze line for Saturday morning. (National Weather Service/Space City Weather)
Good afternoon. Here’s another update on weather for the Houston Marathon, and unfortunately the outlook at this time still favors warm conditions for the morning of January 15.
The GFS model
The North American model is downright warm. According its ensemble output, the GFS model forecasts a 0 percent chance of low temperatures 40 degrees or below on Sunday morning, which would be ideal for long-distance running. Conversely, the model predicts a 60 to 70 percent chance of a high temperature of 70 degrees or above that day. This still leave some wiggle room, but the outlook is not good. Essentially we’d be looking at start-time temperatures in the 60-65 degree range with high dewpoints.
The European model
The European solution is slightly more optimistic. The graphic below is busy, but instructive, so let’s take a moment to explain it. The bottom panel shows “minimum” temperature forecasts for a given six hour period. I’ve indicated the period for Sunday morning’s low temperature, and the range of 50 ensemble outcomes peg it anywhere from 30 degrees to 70 degrees.
However the highlighted green area shows the most likely range of temperatures that morning, from the upper 40s to the upper 60s (the model average is 59 degrees). Similarly the model’s most confident range of high temperatures on Sunday afternoon runs from 60 to 75 degrees.
15-day European model ensemble output. (Weather Bell)
My take on the European model is that it’s forecasting about a 50 percent chance of significantly warmer than normal temperatures, 60 degrees or higher at race time. There’s probably a 25 percent chance of lows from 55 to 60 degrees, and a 25 percent chance of lows below 55 degrees (fingers crossed!).
The only positive thing I can say is this: We’re still nearly 11 days away from marathon day. That is a long time in weather forecasting, and predictions this far out are simply not locked in, even when the models seem pretty consistent. While a warm race day is certainly most likely, it is far from certain. But damn, I have to say the prospect of running a race in the 60s and moderate to high humidity is very, very far from enticing.
Tomorrow I’ll start looking at rain chances as well.
