Weather Headlines:
* Another pleasant day in the Twin Cities area, but a wind shift (more to the north/northeast) cools things off a bit.
* Latest computer run keeps most of the rain to our south/east on Sunday, but .10 to .20" of rain possible, with 4-6 hours of rain for the metro area.
* Clouds, sprinkles may linger much of Monday due to a weak storm aloft.
* More sun next Tuesday and Wednesday as temperatures mellow.
* GFS computer model hinting at temperatures near 80 (!) by next Friday.
* Conditions coming together for possible severe T-storm outbreak a week from today.
Paul's Weather Column
Do you realize we've gone nearly two weeks without a drop of rain in the Twin Cities and across much of the rest of Minnesota? This is how I imagine weather forecasting to be in Palm Springs or Las Vegas or San Diego in the summer. Day after relentless day of blue sky, hardly a cloud in the sky, magically monotonous. I realize many of those cities have professional meteorologists, but my big question is: what do they do? How many times can you say "sunny and hot" before losing your mind? There are exceptions, of course. A strong El Nino can push the jet stream, the storm track, to the south during the winter months, producing a parade of wild, sloppy storms. Then meteorologists in L.A. and Phoenix actually have something to talk about - they can show off their shiny new Dopplers! Rarely do we have the boredom problem here in Minnesota. We usually gyrate from one extreme to the next, for good reason. Cities near the center of large continents tend to experience the wildest weather extremes, while towns close to water tend to have their weather and climate moderated/neutered, if you will, by proximity to large oceans. When I tell my colleagues who live in other (duller) cities what goes on in Minnesota I can see their eyes getting bigger, their mouths agape, yes - it's the "big leagues" of meteorology. If you go to school for weather one hopes to someday work in a place with THIS MUCH WEATHER! So I'll take this little weather-intermission for what it is: a gift from on high, knowing full well that it's just a matter of time before Mother Nature throws a tantrum close to home.
Severe storms, hail and tornadoes are most likely in late spring and early summer here in Minnnesota. Why? A higher sun angle is rapidly warming the ground, and the air immediately above the ground. Meanwhile the upper atmosphere is still chilly, suffering from something of a wintry hangover. This imbalance: cold air above, warm air near the surface, leads to the "instability" that can allow an innocent "parcel" of warm rising air to mutate into a spinning, sprawling cumulonimbus cloud, that from a distance, resembles an atomic blast. May and June are primetime for tornadoes across central Minnesota - if this is an average year about 25-30 tornadoes will form over the Gopher state. There really is no way to tell, weeks in advance, how bad a season it's going to be for nature's most violent wind. I don't see any potential for anything severe until (possibly) next Saturday, a week from today, when there may be just enough warmth and moisture at low levels of the atmosphere, coupled with cold air aloft, and enough "shear", or spin in the sky to focus spinning into a vertical column of rapidly rising air, a severe thunderstorm. A tornado is more of a "process" than an "object", the rotation visible on Doppler radar in the mid-levels of the atmosphere a tip-off that violent rotation may be present on the ground. Thankfully we have hundreds of professional Skywarm volunteers, storm spotters, activated during severe and tornado watches, who provide the ground-truth we need to be absolutely certain a spinning thunderhead on Doppler is really producing a wall cloud, funnel or tornado.
The latest storm looks like it's heading south of us (what's that old adage, "when in a drought don't forecast rain?") It's technically a moderate drought for much of the Twin Cities. Severe drought is gripping far southeastern MN, along the Mississippi River. If this dry pattern were to hang on the rest of the month (doubtful) then I'd start to get concerned about implications for farmers. It's a little early to be jumping the gun, tossing around the "D-Word" in mid April.
Sunday looks gray and a bit foul with temperatures holding in the 40s, a stiff north wind making it feel like 30s. Periods of light rain are expected here in the Twin Cities, where .25" of rain may fall. Skies remain gray much of Monday, but a clearing/warming trend returns by Tuesday and Wednesday. More 60s are likely by the middle of next week. One model (GFS) is insisting we'll be near 80 by Thursday or Friday. I think that may be a bit overdone and optimistic, but certainly we'll sample 70s by the end of next week. Not bad at all for mid April. The chance of showery rains will increase late next week with a 1 in 3 chance of a severe storm outbreak a week from today. Many of the factors will be present - but it's still way too early to know if we'll really see hail and high winds.
Hope you salvaged a fine Saturday. Sunday looks like a good indoor day, a chance to catch up on the dreaded honey-do list, homework, reading, fumbling with your remote control, or maybe offering up a Tweat or two? Are you Twittering yet? I just started, and I'm starting to see the power of this new platform, a great way to be introduced to not only new friends but stories and web sites you might not otherwise find. It's worth checking out. I see Twitter as a very powerful way to get weather reports, and specifically storm reports, in real-time. The way we gather raw weather data is changing, and Twitter, or something similar, is going to be an important part of the reinvention of weather. BTW my Twitter name is pdouglasweather. Tune in, I'll be happy to keep you in the loop with weather updates, interesting stories/URL's, web sites, and maybe send up a flare when I'm flossing. I know you want that kind of stuff, right?
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