Here are experimental radar forecasts that show the development of the winter storm and the potential thunderstorms.
The graphic below is valid at 6pm CST:
The forecast below (courtesy of the NWS) is valid at 10pm this evening:
The above forecasts do not differentiate rain versus snow. From a separate forecast model (hat tip: Dr. Ryan Maue) is the rain versus snow for 6pm this evening:
11:59pm this evening:
6am Friday morning:
This set of graphics should give you a good idea of the timing of the storm.
While the snowfall forecast below still looks good, some preliminary guidance from the new model runs indicate more than a foot of snow may fall farther south in eastern Nebraska and far western Iowa from Grand Island to Lincoln to Omaha to Council Bluffs. While still preliminary, keep this in mind if traveling.
AccuWeather regional radar shows the line of thunderstorms continues to move gradually east across Louisiana and Mississippi but the threat of tornadoes, according to the NWS, had ended. So, they allowed the watch to expire. Strong winds are still possible with some of the stronger storms as the move east the next few hours.
Here is the AccuWeather regional radar at 5:04pm CST. The storms are developing in Arkansas about where expected (see posting below). I’d estimate we’ll see the first warnings in the 6 to 6:30pm time frame as the upper atmospheric low catches up to the unstable air in the Mississippi Valley.
Tornadoes and very high winds are the main threats. Stay tuned.
Right now the airports with delays are LaGuardia and Newark with averages of 16 and 45 minutes, respectively. That will likely change as strong thunderstorms approach Atlanta. A tornado watch has been issued for the area:
Below is AccuWeather’s regional radar at 4pm EST. There is a small thunderstorm just north of the Atlanta airport with strong thunderstorms moving in from the west. Expect major delays when the storms move in.
Nate is the impressive weather producer for WRAL TV in Raleigh. His blog posting here. Nate talks about pilots, weather, and smartphones. I’d like to relay an experience of my own from just last week.
There were thunderstorms occurring around Wichita’s Mid-Continent Airport and I noted the captain looking at his smartphone at the gate. I asked which program he was using for radar. I knew it was one that had a built-in delay of 5 to 7 minutes which could be critical in a thunderstorm situation. I also gave him some additional apps that might be helpful. While I’m not fully comfortable with flight crews using smartphones for radar, if they are going to use it, the radar should be as timely and detailed as possible.
As we taxied out, I could see cloud-to-ground lightning striking the ground. It was one of the few times I have been nervous before a take-off. We got into position at the end of the runway, paused a few minutes (yes, minutes)… and pulled off the runway. It was an hour and forty minutes before we took off, which was exactly the right thing to do.
To what extent my suggestions might have assisted, I don’t know. But, I thanked the crew for a great job when we landed in Houston and they seemed appreciative.
I try not to make this too much of Plains-centric blog but there is a fairly high chance of a thunderstorm event with damaging winds and large hail, especially in the hatched area later today and tonight.
The experimental radar forecast shows the storms just starting to develop in central and western Kansas around 4pm and moving rapidly east or southeast after that time (don’t take this forecast too literally). It is a good idea to bring in lawn chairs, the kids’ trampoline and put the car in the garage.
Note that there is a pretty good chance of thunderstorms around Atlanta and a lesser chance around Chicago, Cleveland, and NYC. LaGuardia already has 15 minute delays as does Washington Reagan. You might want to see if you can get an earlier flight if you are traveling to or changing planes in these areas.