Thursday, 11:15 a.m.
Spring IS coming. It's just not ready to burst upon the scene and wipe out all of the remaining snow cover and give rise to all of the beauty of spring - green grass, colorful flowers, budding trees. Plain and simple, there's just too much cold air in the pattern.
The warmup will be enjoyable the next few days. You're experiencing it today along the Front Range with sunshine, some clouds and temperatures recovering into the 50s and 60s. It will be even milder tomorrow and will remain mild through the Easter weekend. Tomorrow, that warmup will start to spread into the Plains, though there will be some resistance to that warming. There will be a lot of clouds from Texas all the way to the Dakotas, some spotty showers and even a few thunderstorms in the afternoon and evening.
By Saturday, some of that warming will slip into the Midwest and try to cross the Mississippi Valley. Here's the projected temperature anomalies for Saturday:
At this point, there will be two features to track over the weekend. The first of these will move into the northern Plains, rotating southeastward around an upper-level low over Hudson Bay. You can see this feature on the NAM 700mb forecast for Saturday evening:
The actual disturbance will be back in the Dakotas, but the effect of it will be felt across Minnesota into Wisconsin, Iowa and Illinois with some rain. There can be a little snow and ice in northern Minnesota and northern Wisconsin, but to the south it will be all rain.
This disturbance will drive a cold front across the Great Lakes into the Ohio Valley late Saturday night and Sunday morning, pushing rain ahead of it. By the end of the day Sunday, that feature will send clouds and rain across upstate New York, with some snow in the Adirondacks. There will also be some rain in the mid-Atlantic states, and some of that rain with some thunderstorms will also be felt from the Carolinas back into parts of Texas. This isn't likely to result in a big outbreak of severe weather, thankfully.
If you look more closely at the NAM forecast for Sunday evening, though, you'll see there is a second disturbance trailing the first:
The air mass between the two won't be cold at all, and where there is some sunshine on Sunday, it will be pretty mild from Chicago south and east. That's likely to be the case east of the Appalachians on Monday. However, with that second disturbance there will also be some clouds and perhaps a few showers. The main impact of that second disturbance won't be so much the shower chance with it, but the blast of cold that follows. Study closely the thickness packing behind that second feature Monday afternoon:
That's another brutally cold air mass for so late in the winter season. Just look at the projected temperature anomalies on Monday:
That's probably not going to be the last push of arctic air, but here's hoping it's the last one of its strength! There are some indications that may be the case, but I'll look at that in more detail next week.
Two systems will delay the onset of warm weather in the Ohio Valley and the East over the next week or so, but then it should get warm all across the country heading into the Memorial Day weekend.
A turn to much colder air over the Northeast and mid-Atlantic states will set the stage for a rain and snow storm later this weekend before it turns much warmer later next week.
It's warm now, but will turn much colder this weekend, with a storm threat later Saturday into Sunday. Warmth will return by the second half of next week.
Though it is cold now east of the Mississippi, with a couple of opportunities for snow into the weekend, a blast of warmth is due for much of the country east of the Rockies next week.
Warm air will once again surge eastward from the Plains to the East Coast this weekend and early next week. A strong storm next Tuesday and Wednesday will then be followed by colder air later next week.
A storm in Southeast Texas will generate severe thunderstorms this afternoon and tonight, and some wet snow on its western flank as it heads into the Ohio Valley tomorrow.