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Long cool soaking

20 degrees at Embarrass, Minnesota Wednesday morning: coldest in the state

Soaking rain on tap, 1+” rainfall amounts seem likely, heaviest amounts come this afternoon through early tonight.

Plan on a much slower evening commute later today because of the rain.

Showers linger for Friday evening football games, temperatures range from 48-50; expect raw and fairly uncomfortable conditions.

Better news for Saturday games. Odds favor peeks of sun and dry weather most of the day, temperatures from 57-62. Slight PM shower risk over eastern MN, Wisconsin.

Sunday: sunnier, nicer day of the weekend to close up the cabin, take in the dock, rake some leaves (or just watch football on TV).

Twin Cities Marathon: Partly sunny, cool an dry (nearly perfect conditions). 8 am temperature: 45. Noon temperature: 54. 3 pm temperature: 59. Low humidity, winds under 15 mph.

No more 70s, warm fronts nowhere to be found on the weather map. Temperatures run 5-10 degrees cooler than average through most of next week.

Umbrella. Noun. A screen or shade, usually of cloth stretched over a folding radial frame, carried for protection against the rain or sun.

Rummage around the house and see if you can track down one of these handy devices. Brush the cobwebs off the kid’s waterproof jackets while you’re at it. Rain is in the forecast, the most significant soaking in 5-6 weeks, going back to mid August (the last time it really poured). The heaviest, steadiest rains should arrive this afternoon and linger into the nighttime hours. The most reliable computer model (what meteorologists call the “NAM”, for North American Model) is printing out a whopping 1.23″ of rain over the next 84 hours – most of that coming from lunchtime Thursday through midnight Thursday night.

Stating the obvious: we need the rain. We need it bad. A meager .46″ of rain fell in September, 2.16″ less than average for the month. Weather systems were in a holding pattern much of the month: record floods for Atlanta and the southeastern U.S. while high pressure loitered over the Great Lakes and Midwest for the first 3 weeks of the month. Pretty extraordinary. By the way, September wound up 5.9 degrees warmer than average, almost as if Mother Nature was trying to compensate for a cool July and August.

We’re rapidly transitioning into an autumnal pattern, one where precipitation goes from showery “convective”, hit-or-miss – to more of a steady, heavy, widespread pattern where EVERYONE gets wet. During the summer we rely on small, 5-10 mile diameter thunderstorms, intense, localized updrafts, for most of our moisture. But during October and November the air is drier and cooler, less favorable for T-storms. A significant north-south temperature variation sets the stage for broad areas of low pressure, storms that pull Gulf moisture northward, rising up and over cool air over Minnesota, a process known as “overrunning”. As air rises it cools, and can’t hold as much water vapor – moisture condenses out into visible cloud droplets. When these microscopic droplets combine they grow larger, until they get so big and heavy that gravity pulls them to the ground – and we say “it’s raining”. Frankly, it’s easier to predict (with confidence) if a specific town is going to see rain in October than in July, when showers are totally random and fickle: one town will get a 5″ soaking, while 3 miles down the road the sun is out and people are mad because it’s not raining! Talk about frustrating.

WRF/NMM (NAM) Model Output valid 7 pm this evening. Note the heaviest/steadiest rains are forecast to set up over western and central Minnesota, .75″+ (just between 1 pm and 7 pm today!) Let’s hope the models are right. They’ve been pretty consistent, calling for significant rain, so I’ll be shocked if we totally miss out on the puddles later today. Prepare for a longer, slower drive home after 3 pm with moderate rain.

I’m reasonably confident that everyone will see rain by midday, heavy at times this afternoon and evening. Showery rains will linger into Friday as a strong storm tracks just south of St. Cloud, keeping us in a raw, moist east/northeasterly flow. If it were early November (and about 15 degrees colder) we’d be looking at somewhere between 12-24″ of snow, by the way. While you contemplate that scenario, some better news for the weekend. Yes, we’re scheduling soaking rains for workdays, when we’re cooped up indoors at work, home and school, saving the cool, refreshing sunlight for weekends whenever possible. The sun should peek through Saturday, although a stray PM shower can’t be ruled out, especially across eastern Minnesota and Wisconsin. Sunday looks sunnier and a bit milder statewide before the next round of showers arrives Monday-Tuesday of next week. Yes, we are sliding into a wetter pattern, and frankly, it’s about time. I’m looking forward to pressing my face up against a rain-splattered window, maybe sloshing around in a few puddles on my way out to start the car later on.

Your lawn, your garden – shrubs and trees (not to mention farmer’s fields) will be LOVING this long, cool drink – it’s just what we needed, a chance to recharge soil moisture before the ground begins to freeze up, roughly a month from now. A few more storms like this would put us in pretty good shape going into the winter. The drought is still hanging on (latest update tomorrow) but I’m hopeful that the pattern is shifting, we are getting wetter, I just hope we can benefit from this moisture before the ground freezes up solid as a rock.

Paul’s Outlook for the Twin Cities

Today: Cloudy, rain developing by midday, getting steadier/heavier this afternoon (slow drive home later today). Winds: East 15-30. High: 55

Tonight: A soaking rain, heaviest before midnight. Low: 48

Friday: Cloudy, periods of rain (not quite as heavy). Still cool, raw and damp. High: 54

Saturday: Step in the right direction. More clouds than sun, brief PM sprinkle but definitely drier. High: 57

Sunday: Nicer day, plenty of sun, few degrees milder. High: 61

Monday: Clouds increase, chance of showers late. High: 58

Tuesday: Mostly cloudy, showery rains likely. High: 57

Wednesday: Still unsettled and rather damp, a stray shower or sprinkle. High: 56

Comments (1)

  1. Submitted by Mike Nagell on 10/01/2009 - 09:45 am.

    If we are going to start getting rain, it’s important for homeowners to check their gutters and sump pumps. Make sure your gutters are clear of debris and your downsount extentions are secure. Manually activate your pump now. Make sure it can do the job when the rains come.

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