Thursday, June 17, 2010

The Benefits of Whale Poo (and a pretty nice weekend outlook)

"Mamma". The view outside WeatherNation World Headquarters in lovely Excelsior (technically Shorewood) Thursday evening, a setting sun illuminating cumulonimbus mammatus clouds forming on the underside of a severe thunderstorm anvil, hail falling out of the top of this massive warm-weather-rain-machine. Quite a sight.


Vortex 2. Nice to see the professional storm chasers from NSSL in Norman, Oklahoma, trying to gather more data on tornadic thunderstorms - what you're looking at is a Doppler radar on wheels, able to get to within a few hundred feet of a tornado on the ground to get a level of resolution and accuracy not possible from NWS Dopplers around the USA. Photo courtesy of Todd Nelson (of WeatherNation fame) who was on his way to a softball game, came across the Vortex 2 convoy!


* Slight severe risk over far southeastern MN, western WI again Friday.

* Free Air. Drop in temperature/humidity Saturday - nicer day of the weekend, highs ranging from mid 70s north to low 80s far south.

* Slowly Souring Sky Sunday: sunny start, but clouds increase by mid afternoon, growing chance of showers/T-storms from late Sunday into Tuesday of next week.

* Grandma's Marathon Saturday in Duluth: early AM temperatures in the mid 50s, partly sunny, breezy and comfortably cool, morning readings rise through the 60s, peaking at a high near 70. No precipitation expected (remember sunscreen - sun as high in the sky as it ever gets).

Paul's Conservation MN Outlook for the Twin Cities and all of Minnesota

Today: Plenty of sun, slight drop in humidity. Few T-storms possible by late afternoon, a tiny percentage may turn severe over far southeastern MN and western WI. Winds: SW 5-15. High: 86

Friday night: Clearing, comfortable. Low: 61

Saturday: Probably the nicer day of the weekend. Blue sky much of the day. Winds: W/NW 10-20. High: 79

Sunday: Sunny start, PM clouds increase, a few late-day showers and T-storms. high: near 80

Monday: Humid with more numerous T-storms. High: 81

Tuesday: Partly sunny, isolated T-storm. High: 83

Wednesday: Drier with more sunshine. High: 82

Thursday: Lot's of sun, quite pleasant. High: near 80

34 separate tornado reports in Minnesota Thursday, more than half the 61 tornadoes tracked in the skies over the USA. A complete rundown on tornadoes (as well as hail and damaging straight-line winds) is here, courtesy of SPC, the Storm Prediction Center.

What a day. Nothing like tip-toeing into tornado season. All or nothing. Tornado damage reports are still coming in, before it's all said and done there may have been as many as a dozen separate tornadoes forming above Minnesota's skies Thursday afternoon and evening, from near Grand Forks to Buffalo/Wadena on south to the Albert Lea area, where a 1/2 mile "wedge" tornado caused quite a scare.

Buffalo Funnel. Here is the wall cloud that dropped a funnel and possible tornado on the north side of Buffalo, courtesy of WeatherNation meteorologist Todd Nelson.

24 hours ago I went out on a ledge and predicted that Thursday would bring the first tornado outbreak of the season for Minnesota, but I was surprised by the extent (and intensity) of some of these twisters. You know it's going to be a busy day when professional tornado chasers (from Oklahoma and Kansas) are spotted on Minnesota's major highways, converging, calculating, plotting and scheming - trying to get the "money shot" of a tornado on the ground that will earn them a few thousand bucks in one evening.

Now comes news of at least one fatality in Almora, in Douglas county, the same thunderstorm that produced GRAPEFRUIT-size (4"+ diameter) hail and a wedge tornado left at least one person dead, Minnesota's first tornado fatality of the year. I was on the air this afternoon talking about that cell, it was producing wind shear of close to 100 mph (50 mph. of spin in both directions) and hail off the scale. Again, the larger the hail, the stronger the updraft necessary to sustain millions of tons of ice in the air, the stronger the updraft, the higher the probability of spinning up nature's ultimate updraft, a tornado.

What happened? A cold wrinkle of air aloft, marking the leading edge of drier, more comfortable, lower-dew point air (that we'll be enjoying today) irritated a warm frontal boundary snaking from northwest to southeast across the state. The wind profile (veering winds with altitude) was ripe to translate horizontal wind shear into vertical wind shear, and where rising thermals of warm, moist air broke through a weak inversion, that "spin" was focused in the vicinity of violent thunderstorm updrafts, resulting in softball-size hail and tornadoes, something that happens maybe 3-5 times/summer season.

Good news: probably no quality time curled up in your basement today, Thursday's thundery frontal boundary has gotten a gentle nudge to the south/east, a southwest breeze will insure sunshine and mid 80s today as dew points drop back into the 50s, a slight chance of a late afternoon/evening T-storm over southeastern MN, from the Twin Cities on south and east to Eau Claire, Rochester and the Iowa line. That said, most Minnesotans won't have to worry about severe storms today, but we can't rule out large hail and winds.

Slight Severe Risk. Southeastern MN and western Wisconsin will be close enough to spark a few strong/severe storms again by late afternoon, the best chance just south/east of the Twin Cities, toward Rochester, Albert Lea, Winona and La Crosse.

Winds shift around to the west Saturday, meaning a more noticeable dip in temperature and dew point, highs in the 70s to near 80, plenty of sunshine statewide, although PM clouds may build up north. I still believe Saturday will be the better day of the weekend (God-willing) the first decent Saturday in just about a month. We're due for a break - right now I don't see any flies lurking in the weather ointment - no stalled fronts, rippling storms or upper-air disturbances. Is my comfort level 100%? No, it never is - I'm still pretty paranoid after the last few Saturdays, wary and weary that something may pop up (literally) at the last moment. Looking good (so far) but I want to see one more computer run before I exhale and firm up my outdoor plans.

Cautious optimism.

Sunday should start out sunny and pleasant, but clouds increase later in the day as a frontal boundary returns from the south, sparking a few random showers and T-storms late Sunday into Monday, possibly Tuesday.

No Fishing. According to NOAA 34% of the Gulf of Mexico is now closed to commercial fishing. The latest here.

* 6 Ways to Visualize the BP Deepwater Horizon Spill. An assortment of ways to keep up with what's happening in the Gulf of Mexico here.

French Flooding. At least 11 people have been killed, another dozen or more missing from 10-20" rains along the Mediterranean Sea. The story from Reuters is here.

Earthquake Monitoring. New ways to detect earthquakes in advance, an interesting story from USA Today here.

Whale Poo Helps in Fight Against Global Warming. This one had me scratching my head - to get just as confused as I am click here.

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