‘Thundersleet’ today, ‘spring’ on Thursday as we near 60 degree record mark

Positivity

Things are looking up in the Weather Lab these days.

After one more bout of potentially winter-flavored weather later this afternoon and evening, the spring of 2013 will finally kick in starting Thursday.

This time it even looks like it might stick around, for at least a few days.

In the meantime we endure one more shot of potentially mixed precipitation later today as April attempts to hurl one more wintery insult our way: a potential rainy "thundersleet" storm around suppertime tonight?

With 70 degrees in the forecast this weekend, we can handle this.

I think.

In this Updraft we track one last wintery gasp this evening, and looks forward to the warmest days in 5 months.

Nov. 22 - Last 60 degree day in the Twin Cities (5 months ago)

Oct. 21 - Last 70 degree day in the Twin Cities (6 months ago)

More on "Thundersleet"

Our sunny morning may turn into an "interesting" weather evening.

The last incoming cold front for a while brings strong upper level support late today. The result will be strong "Upward Vertical Velocity" (UVV) between about 4 p.m. and 8 p.m.

Translation? There will likely be enough buoyancy or "lift" in the atmosphere overhead to produce a few thunderstorms in southern Minnesota and the metro as the front sweeps through around dinnertime.

Surface temperatures may reach the upper 40s or even 50 degrees in a few spots. With much colder, sub-freezing air aloft there is a chance that thunder may be mixed with sleet and small hail later today. How nice!

While we likey won't be warm enough to generate severe storms, NOAA's Storm Prediction Center found enough reason to circle southern Minnesota in the "general T-Storm" area today.

Get used to looking at this map the next few weeks. There is a small chance for our first severe weather watches of the season Sunday night into Monday. Looking at the maps with our lingering chill and rapid warm up, this has the potential be a more active spring than last year.

2013: Year of "Impact Based Warnings" in Minnesota

NOAA will trot out the new impact based warnings for all central region states this year including Minnesota, Iowa, Wisconsin and the Dakotas.

The new, graphic "enhanced wording" is designed to get your attention.

Here are the details from NOAA.

60 degrees: Better late than never

Okay, so we have never failed to reach 60 degrees in Minnesota since the last ice age. But some of us were beginning to wonder.

The last time we hit 60 degrees was 5 months ago, on Nov. 22. And no, that's not even close to a record in Minnesota.

This year it looks like we may come within 3 days of the latest 60 degrees on record in the metro.

If we hit 60 degrees as forecast on Friday, it will tie for the second latest date on record.

The details from the always timely and excellent MN Climate Working Group. (Click for a bigger view)

April 25, 2013: The day spring began for real?

Some years in Minnesota there are clear, abrupt dates of seasonal transition.

This year, it looks like we may be able to say spring began for real on Thursday, April 25.

Tomorrow our winds will shift into the southwest, and a sustained flow of midler air will blow in from the Southern Plains and Desert Southwest. That should boost temps well into the 60s and even 70s this weekend in Minnesota.

Check out the balmy NWS forecast numbers for this weekend in the metro.

All (and I do mean all) the forecast models are pushing the 70 degrees isotherm into the Twin Cities this weekend.

The large scale signals from the Arctic Oscillation are much more positive than in recent weeks. Still, there are some signs it may flip back more negative (cooler) later next week.

While the upper air pattern looks radically different (warmer) this weekend, there are some signs we may cool off (possibly significantly) again later next week.

Stay tuned as we see how the forecast models evolve on that one. In this unforgiving spring of 2013, I'm just not ready to say spring is here to stay for good -- just yet.

In the meantime this weekend: Enjoy!

Paul Huttner