Wednesday, September 23, 2009
A September for the record books
What you need to know....
Today: Intervals of sun, mid to upper 70s (10+ degrees above average). Last lukewarm, shirtsleeve day in sight for the next week or so.
Friday: Half an inch of badly needed rain possible - wettest day in sight.
Saturday: Unsettled, lot's of clouds, passing shower (dry most of the day).
Sunday: Gusty, turning colder with more showers, winds top 35 mph, falling temperatures.
Monday: Feels like mid October! Temperatures stuck in the 50s, wind chill in the 30s, first flurries possible up north?
What a month. Temperatures are averaging close to 7 degrees warmer than normal - statistically very significant (by comparison July/August temperatures were 1-2 degrees cooler than average). Much of July jet stream winds, the prevailing winds 4-6 miles overhead, were howling from the northwest, a pattern more typical of September. Only now that it's September winds aloft are light and erratic, storms stalling, meandering, stalling - producing copious/flooding rains. That's what you'd expect to see in mid summer, July, when winds aloft tend to be lightest, storms most likely to stall (and flood). So let me get this straight: we had September in July, and now we're having July in September. Makes sense to me.
But try explaining our wacky weather to dazed residents of Madison, WI, still drying out from nearly 4" of rain on Monday, the 8th wettest day in Madison history. Conditions in Georgia are considerably worse, with more widespread flooding - some towns have picked up 12-18" of rain so far in September, about half a year's worth of rain falling in little more than 2 weeks. Very strange. Yes, weather is often extreme & unpredictable, but I can't remember a summer season that turned out to be this big a head-scratcher. Just when you think you've seen everything....along comes a year like this. Kind of makes you psyched for the winter huh?
Let me do my San Diego weather-dude impersonation: "fog and stratus will burn away between 10 and 11 am, plenty of midday and afternoon sunshine, enough for highs in the upper 70s." A few optimistic bank thermometers (receiving direct sunlight) may flash 80 degrees in the shade. Not too shabby for September 24, considering we could be scraping fancy designs into frosty windshields and tracking snowflakes up north by the 4th week of September.
Friday Puddles? The latest WRF/NMM model shows significant rain surging into Minnesota from the south/southeast on Friday. Some 1-3" amounts are possible close to home - right now it's premature to know where the heaviest rain bands will set up, but Friday may bring the best chance of rain we've seen yet this month. Considering we've picked up a whopping .18" so far in September it would be great to look out at a landscape covered in puddles, especially if we're stuck at work and school. Friday appears to be the wettest day, the latest model prints out just over half an inch of rain - we dry out a bit on Saturday; the next cold front sparking another outbreak of scattered, spotty showers on Sunday.
Another Solution. A variation of the WRF model is printing out less rain across Minnesota by Saturday morning, keeping the heaviest (1-2") amounts over far southeastern Minnesota and eastern Iowa.
Speaking of the s-word: a few of the computers are adamant that the jet stream, the high-speed river of air that pushes weather systems around the globe, will BUCKLE by Sunday, plunging a rude blast of Canadian air into Minnesota. We'll be lugging around hefty jackets from late Sunday into Tuesday as winds gust to 40 mph. Sunday night and again Monday night (after dark) it may be chilly enough aloft for a few snow flurries to reach the ground. Not sure about accumulation (ground temperatures are still very warm - not sure anything will be able to pile up downwind of the Great Lakes) but it will FEEL cold enough to snow by Monday evening across much of Minnesota and Wisconsin. I could say something pithy and profound like "we're overdue" or "you KNEW this was going to happen" but I have more respect for you than that. Look, we've gone the entire month of September without shivering. The sun is as high in the sky now as it was back on March 20 (!) so yes, we're due for a change in the weather. If it's any consolation a rapid warming trend is likely next week (back into the 60s) and the long-range GFS model is hinting at 70 the first week of October.
It's just a taste, a refreshing slap across the face, an omen of what's to come. Go ahead and bring some of the longsleeve shirts, sweatshirts and jackets out of cold storage. Put away the lawn chairs, get the dock out of the water (now!) while it's still relatively pleasant. Put this expanded/extended summer to good use - you'll thank yourself with the snow is falling (horizontally) and that annoying guy down the hall greets you with the latest wind chill reading. Something to live for....
Paul's Outlook for greater St. Cloud
Today: Partly sunny, unseasonably warm for late September. Winds: SE 5-10. High: 78
Tonight: Mostly cloudy, slight chance of a shower late. Low: 55
Friday: Mostly cloudy, period of rain, possible thunder. High: 66
Saturday: Lot's of clouds, unsettled, passing shower or sprinkle. High: 63
Sunday: More showers, then gusty, turning cooler. Winds gust to 35+ High: 65 (falling into the 50s PM hours).
Monday: Blustery and cold with clouds and sprinkles. Winds gust from 20-40 mph. High: 56
Tuesday: Partly cloudy, winds ease a bit. High: 62
Wednesday: Fading sun, milder. High: near 70
Thursday: Showers possible. High: 63
Friday: Showers taper, turning breezy and cooler. High: near 60