Monday, May 11, 2009

Showers blossom over central Minnesota

(Afternoon update, 2:35 pm). Doppler radar shows light to moderate showers sprouting across much of central Minnesota, popping along a warm frontal boundary. A thunderstorm can't be ruled out this afternoon, but the moisture and wind profile of the atmosphere is not ripe for a severe storm outbreak anytime soon.

Don't let the daffodils and tulips fool you. Only the brave (and foolhardy) are planting annuals this early. Last night's patchy frost was a rude reminder that frost is quite prevalent across central Minnesota through the third week of May. The general rule of thumb holds: if you want to be ABSOLUTELY safe: wait until Memorial Day to plant your vegetable patch.

The average date of the LAST 32 degree low in St. Cloud: May 12 (NWS data). That's just the average, mind you. Here is some additional data for towns across central Minnesota:
MEDIAN DATES OF CRITICAL LOW TEMPERATURE THRESHOLDS IN MINNESOTA
(Period of record 1948-2005)

DISTRICT MEDIAN DATE OF MEDIAN DATE OF DAYS BETWEEN
AND LAST MIN. TEMP FIRST MIN. TEMP MEDIAN DATES
STATION IN SPRING IN FALL
24 F 28 F 32 F 32 F 28 F 24 F 32 F 28 F 24 F

Chaska       4/11  4/22   5/2    10/2  10/10 10/27  152   173   200
Collegeville 4/10 4/22 5/2 10/5 10/18 10/29 157 177 201
Gaylord 4/9 4/17 4/29 10/4 10/16 10/24 158 181 198
Hutchinson 4/9 4/24 5/1 10/1 10/13 10/25 152 175 200
Jordan 4/13 4/28 5/10 9/28 10/6 10/20 144 164 190
Litchfield 4/11 4/22 5/5 9/30 10/10 10/23 153 171 195
Little Fls 4/19 5/3 5/12 9/25 10/5 10/18 138 158 182
Long Prairie 4/20 5/1 5/15 9/22 10/2 10/13 129 155 178
Melrose 4/13 4/28 5/11 9/25 10/5 10/17 139 162 188
New London 4/13 4/24 5/5 10/3 10/13 10/24 153 171 191
St Cloud 4/18 5/1 5/12 9/24 10/5 10/17 138 157 181
Santiago 4/18 5/2 5/16 9/22 10/1 10/13 127 152 175
Stewart 4/9 4/22 5/6 10/1 10/10 10/22 147 172 194
Wadena 4/21 5/2 5/10 9/24 10/4 10/19 138 156 179
Willmar 4/11 4/25 5/2 10/3 10/15 10/25 154 173 195

Weather Headlines

* Sunday high of 57 in St. Cloud with a trace of rain.

* Today looks significant warmer than Sunday, but the chance of bumping into a shower or thunderstorm increases later today, tonight and Tuesday.

* Windiest day of the week: probably Wednesday. Cool frontal passage whips up 30 mph+ gusts.

* Quiet, tranquil Thursday, another spirited round of showers (thunder?) Friday.

* Damp start possible Saturday, but rapid clearing expected - most of next weekend looks dry and seasonably mild.

Paul's Outlook

Monday: Sun giving way to partly cloudy skies. Slight chance of a late afternoon shower. Winds: S 5-10. High: 68

Monday Night: Better chance of showers, possible thunder. Low: 54

Tuesday: Unsettled, more humid with a passing shower or heavier T-storm. High: 69

Wednesday: Showers taper early, turning windy and cooler. High: 67 (early), falling during the afternoon.

Thursday: Bright sun, very pleasant, a bit cooler. High: 63

Friday: More showers, risk of a storm or two. High: 65

Saturday: Damp start, then increasingly sunny. High: 62

Sunday: Probably the nicer day of the weekend (again). More sun, less wind. High: 67


Paul's Column

Both boys were in town over the Mother's Day weekend, a good excuse to see the new Star Trek movie twice. I'm not a movie critic, nor do I play one on TV, but the film was superb, a perfect mix of plot, character development and special effects that did a fine job (in my humble opinion) of laying out a plausible start to the Star Trek series. It's fascinating (at least to me) that going to the moon was considered science fiction as recently as the 1940s. Creating a "cyborg", half man, half machine (aka the Terminator series) is technically science fiction, and yet every year we seem to creep a little closer to science-fact, with advanced prosthetics for amputees and military innovations centered on creating a "super-soldier" come to light.

Weather modification has always tip-toed around the edges of science fiction: stopping a tornado, steering a hurricane away from a heavily populated area, stopping global warming by spraying cooling chemicals into the upper atmosphere. A few scientists have proposed putting down a thin film of oil on warm seas in advance of a hurricane, hoping to reduce the evaporation of warm ocean water that gives hurricanes their fierce strength. Detonating bombs inside tornadoes has been suggested (although what happens if the missile misses and hits nearby homes instead?) With all our technology and advances I seriously doubt we'll ever be able to modify weather on a grand scale - the energy required is just staggering, on a scale seemingly impossible for man to duplicate. In rare cases we can enhance snowfall over mountainous areas (cloud-seeding) and clear fog from runways, but - hopefully - a mad scientist in a dark room manipulating weather or storms will always remain in the realm of science fiction.

I'm deliriously happy we salvaged a pretty nice Sunday for mom, who deserved nothing less. Winds eased a bit and temperatures recovered to 57, still cooler than average, but the lack of a stinging wind made it feel tolerable out there. Today should be noticeably milder with a shot at 70 degrees close to home, mid and high-level clouds scuffing up the sun as the day wears on, a breeze picking up from the south. This warm frontal passage, coupled with marginal instability aloft, may spark a stray shower later today; the chance of showers and storms increases tonight and Tuesday, a few towns could pick up a quarter inch or more of rain. A blustery cool front arrives Wednesday, the run cuts off (for at least 36 hours), but a fast-moving weather pattern will shove more showers and assorted storms over our heads by Friday.

The good news: any lingering puddles should dry out first thing Saturday: sunshine the rule much of Saturday and at least the first half of Sunday, before yet another fast-moving system arrives with a slight shower/thunder threat for late Sunday. At this rate watering the lawn and garden should be optional for at least the next week to 10 days. But do yourself a favor and hold off on the tender annuals for another couple of weeks, just to be safe. Nothing more annoying than frost on your tomatoes...

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