Thursday, July 2, 2009

Update: 4th of July Outlook (latest)

O.K. I just got a look at the latest model, what is (allegedly) the most accurate weather model, the WRF/NAM. There are some changes to the weekend outlook I feel compelled to share: most of the weekend still looks dry and lukewarm, but there will be a nagging thunder risk late each day tomorrow and Saturday (the 4th). Sunday now appears to be the driest day, except for some lingering showers over the Minnesota Arrowhead. There's no question that the heaviest showers and thunderstorms will pass well south of Minnesota, soaking Iowa, Missouri and Illinois. We will (once again) be on the northern fringe of any shower activity. In general: the earlier in the day you plan your outdoor events the safer you'll be. The best chance of a few random showers/storms late Friday and Saturday will come between 4 and 8 pm, affecting maybe 20-25% of the state, at most. The farther north/east you go the next couple of days the sunnier/drier the weather should be. The closer you get to the Iowa line the greater the chance of late-day T-storms. A few headlines:

Friday: Sunny start, clouds build in the afternoon with a few late afternoon and evening showers and thunderstorms, mainly over the southern third of Minnesota - the best chance of a couple hours of late-day rain coming south of Willmar and the Twin Cities. Highs: 77-81. Winds: North 5-10.

Saturday (4th): Sunny start, still unsettled with a few scattered late-afternoon and evening showers and T-showers popping up. Once again the best chance of an hour or two of rain around the dinner hour will come over the southern third of Minnesota, generally south of St. Cloud and the Twin Cities. Highs: 77-82. Winds: Southeast 5-10.

Sunday: In something of a computer flip-flop Sunday now appears to be the driest day, with sunny, dry weather most of the day across most of Minnesota. Computer models are hinting at a few lingering showers over far northeastern MN, over the MN Arrowhead, keeping temperatures in the 60s to near 70 near Duluth, Grand Rapids and Tower. Highs: 77-82. Winds: Southeast 5-10.

Summarizing: 90-95% of the holiday weekend still looks dry, the best chance of late-afternoon thunder should be over southern Minnesota, winds will be fairly light, daytime highs near 80 each day, pretty close to average for early July. All in all I give the weekend weather a B+ (better than average for a major holiday!)

WRF/NAM Outlook for Friday morning at 7am, hinting at an isolated shower south of the Twin Cities, but generally dry, sunny weather for most of Minnesota and Wisconsin.

Outlook for 7 pm Friday evening, showering scattered showers and T-storms, most widespread south of St. Cloud and the Twin Cities. The northern lakes region will probably stay dry.

Outlook for 7 am Saturday morning, showing a few lingering showers over far southern counties, dry weather prevailing across most of the state. The earlier in the day you plan your outdoor event, the greater the odds of dry weather.

Forecast for 7 pm Saturday evening, hinting at light, isolated rain showers, mainly south/west of St. Cloud and the Twin Cities. Although it may be a close call, odds still favor generally dry weather for fireworks over central and northern Minnesota.

Sunday morning at 7 am, showing leftover showers and storms over far southern counties, and a few isolated rain showers up north. Again, no steady, all-day rains are expected.

WRF/NAM Outlook for Sunday evening at 7 pm. This outlook shows accumulated rain for the previous 12 hours, during the daylight hours Sunday, suggesting dry weather over most of central and southern Minnesota, but cooler, showery weather over the MN Arrowhead. If the sun is out most of the day (expected) highs should reach 80 degrees.

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