Monday, July 20, 2009

Tuesday AM Soaking?

Sunday morning lows (minimum temperatures) around the state of Minnesota:

53 Twin Cities (normal low is 63).

43 St. Cloud (new record low for July 19).

37 International Falls (new record, old record was 43 F, set in 1958)


Paul's Outlook


Today: Warm sun much of the day, breezy. Winds: south 10-20, gustier PM. High: 81

Tonight: Clouds increase, growing chance of showers and heavy thunderstorms. Locally heavy rainfall possible with a few of these storms. Low: 63

Tuesday: Lingering showers and T-storms early, then partial clearing. High: 78

Wednesday: Mix of clouds and sunshine, warmer. High: 82

Thursday: Plenty of sunshine, a nice dose of summer! High: 85

Friday: Ample sun, chance of late-day T-showers. High: 84

Saturday: Cooler under a partly sunny sky. T-storms possible far southern MN. High: 79

Sunday: Mostly cloudy with showers, windy and cool again. High: 75

Monday: Stalled pattern once more....Mostly cloudy and showery, a damp wind. High: 72

 TEMPERATURE IN F:       :PCPN:  
=================================
1 2 3 4 5 6A 6B 7

DY MAX MIN AVG DEP HDD CDD WTR
=================================

1 73 56 65 -7 0 0 0.04
2 80 57 69 -3 0 4 0.00
3 80 62 71 -1 0 6 0.00
4 78 63 71 -1 0 6 0.15
5 84 58 71 -1 0 6 0.00
6 85 62 74 1 0 9 T
7 83 65 74 1 0 9 T
8 79 64 72 -1 0 7 0.00
9 81 60 71 -2 0 6 0.01
10 89 67 78 5 0 13 0.02
11 79 62 71 -2 0 6 0.00
12 79 63 71 -2 0 6 0.00
13 82 60 71 -2 0 6 0.00
14 80 65 73 0 0 8 0.04
15 78 62 70 -3 0 5 0.00
16 71 56 64 -9 1 0 0.00
17 65 57 61 -13 4 0 T
18 67 56 62 -12 3 0 0.00



July Data for the Twin Cities from the National Weather Service.

* 3.2 degrees F. cooler than average so far.

* 14 of 18 days: cooler than average, largest extremes came third week of July.

* Only 5 days with more than a trace of rain reported. Only .26" of rain so far in July (running a 2.11" deficit just this month).

* 6 mornings so far in July waking up to metro temperatures in the 50s.

* Historically, this is just about the hottest weekend of the year, on average, across most of Minnesota.




WRF/NMM Precipitation Outlook for Tuesday morning. This is what the computer model is predicting for rainfall amounts between 1 am and 7 am Tuesday morning. Some very impressive amounts are possible over central Minnesota, especially just north of St. Cloud, where the models are hinting at some 3"+ amounts (in 6 hours, mind you!) which would imply some very heavy, slow-moving thunderstorms moving through. I'm skeptical that rainfall amounts will be anywhere close to that amount, but some .25 to .75" rainfall tallies seem realistic, a few farms and lawns may soak up close to an inch of rain Tuesday.

Another frontal boundary arrives with potentially heavy showers/thunderstorms late tonight into part of Tuesday, the timing is still tricky, but Tuesday morning's "rush hour" may be anything but. Several inches of rain is expected over parts of central Minnesota, less amounts closer to the Twin Cities, Duluth and Rochester. Remember we're in a moderate/severe drought, down anywhere form 2-4" of rain since June 1, closer to 6" since April 1, so bring it on!

GFS Prediction for 7 pm next Sunday evening. This graphic shows predicted rainfall from 7 am to 7 pm next Sunday, with almost "spiral" bands of showers setting up around yet ANOTHER upper level, "cut-off" low forecast to spin up - AGAIN (!!) over Hudson Bay, Canada. This is unbelievable - incredible - almost supernatural! Some sort of blocking pattern or strange oscillation is preventing this "block" from transitioning into a new phase. This is the same pattern that sparked 60s, record chill and long faces from last Thursday into Saturday, and if - IF this model is accurate, we may be in for another round of cool, wet and windy from next weekend into the last few days of July. A far cry from a week ago when the GFS was hinting at 90s for the last few days of July. Just goes to show how fast the (long-range) forecast can go south.

The next clipper-like disturbance dropping southeastward out of Canada may rile up a shower or storm anytime late Friday, before a drier, cooler, lower-humidity breeze whips up behind the front Saturday, temperatures probably stunted in the 70s once more. It's hard to fathom, but that same GFS model is painting another unusually vigorous, another chilly, rainy, stormy swirl over the Great Lakes and Upper Midwest from next weekend into the first few days of next week. Maybe it's El Nino, perhaps it's something else, but it's just uncanny how the atmosphere wants to keep getting locked in a pattern that favors almost autumnlike weather from the Dakotas to New England, while much of the south, west (and oddly enough: Alaska) bakes under record heat. Enough speculation, just know that no 90s are shaping up, quite the opposite with temperatures quite a bit cooler than average for late July. Wait, how the heck did it get to be late July?


Is it just me, or have you noticed that every summer seems to fly by just a little bit faster than the one before?



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