Friday, 11:55 a.m.
Severe weather has been largely absent over the past month or so. That's another indication of how dominant the cold weather has been. With water temperatures in the northern and western Gulf of Mexico running below average, the return flow of moisture from off the Gulf ahead of any storms has been somewhat reduced, making it that much harder for severe weather to get organized. Here's the most recent sea surface temperature anomalies:
Finally yesterday a few severe thunderstorms erupted, and from them a few tornadoes touched down in northern Missouri. The severe weather reports over the past 24 hours:
Now look at the current dew point temperatures across the Gulf Coast:
Even though the upper-level trough of low pressure coming across the southern Plains isn't terribly strong, it's enough when combined with the greater abundance of low-level moisture to generate lots of strong thunderstorms, some of which will be severe this afternoon and tonight:
As with most any spring storm, especially early spring, there is a cold side to the storm, and on the cold side of the storm tonight and tomorrow into Sunday, there will be some snow. That snow could break out in parts of central and northeastern Illinois and the northern half of Indiana, then become an issue tomorrow afternoon in northern Ohio and far northwestern Pennsylvania. That continues tomorrow night across upstate New York, then over to northern Vermont, northernmost New Hampshire, and parts of central and northern Maine. For these latter areas, its not all that unusual for snow, potentially heavy snow, at the end of March.
Another aspect of this one-two punch of storms will be the excessive rains. Look at the latest NAM forecast of total precipitation from 12z Friday through 12z Monday:
The heart of the heavy precipitation in the Northeast is 2 to 3 inches or more, and that does raise the worry of flooding.
Behind the storm, the good news is that there will be a period of mild, spring weather next week from the southern Plains to the Ohio and Tennessee valleys to the East Coast. Many places will get at least two days with highs in the 60s, and the farther south you go, the warmer it will be. There is still a lot of cold air to the north, but for at least those few days, it will be held at bay.
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.
A major spring storm will move from Texas tonight to the eastern Great Lakes Wednesday night, producing heavy rain and severe thunderstorms, with a swath of heavy, wet snow on its western flank.