Updated 11:51 a.m.: 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.
The pressure’s on. If you look carefully you can see my fingers tremble as I point to the weather map (no, it’s not the bad coffee at the office). Sleepless nights spent tossing and turning, an underlying fear to turn on my laptop and have a look at the latest weather models.
Here is the ultimate source of my paranoia: in 1977 I was a freshman at Penn State, studying meteorology. I had a little company on the side, “Total Weather”, providing updates to radio stations out of my dorm room. So as not to wake my roommate I’d drag a chair, notebook scribbled with weather verbage and a specially wired telephone/microphone into my closet (so as not to wake up my slumbering roommate, who was – in retrospect – a very good sport). I’d spend a couple hours in there, doing weather for 11 FM and AM radio stations, one after another, then stumble out of the closet to shower and get ready for (ugh) first period classes. Yes, it gives new meaning to “coming out of the closet.” Sorry. An aside: strange but true. Some of the Penn State football players used the bathroom, conveniently located right next to our little dorm room. Several of these 300 lb linebackers and fullbacks started circulating rumors that the bathroom was haunted – they swore they heard disembodied voices echoing off the walls at 5 am. Turns out it wasn’t a ghost, ghoul or warlock. No, it was me, next door, babbling about a threat of thunderstorms in Williamsport, Pennsylvania. I never had the heart to tell them it was me. No, chalk that one up to self-preservation. Back to my long-winded story. On July 4, 1977 I predicted “partly sunny with a few sprinkles” for Williamsport. I was confident, not cocky. Two days later I was slumped over the weather maps, peering out the weather station at Penn State at a driving, horizontal rain. The town of Williamsport picked up several inches of rain, minor flooding, washed out picnics, fireworks were cancelled. For 15 years after that forecast I couldn’t go to Williamsport without someone giving me an earful about my “crappy little 4th of July forecast.” Yes, when it rains on holidays locals have LONG memories. That is, perhaps, the worst weather sin you can commit. Predict a nice holiday weekend, only to have it POUR for 10 straight hours. It was a humbling experience to say the least, underscoring my theory that one can’t learn how to predict the weather out of a college textbook. The only way to learn how to forecast the weather? Trial and error. Error and error. In theory: you (slowly) learn from your mistakes, although it’s inevitable you’re going to create NEW mistakes over time. Yes, it’s a very painful learning curve.
That’s why I (secretly) dread the 4th of July. It still conjures up some very embarrassing memories of forecasts gone bad.
WRF/NAM computer model prediction for 7 pm Saturday, the 4th of July, hinting at generally dry weather for the eastern half of Minnesota, including St. Cloud, the Twin Cities, Duluth and Rochester, with scattered T-showers over western counties, maybe some strong/severe storms over the Red River Valley.
So, with all humility and caution I can predict a fairly nice holiday weekend for us, not “perfect”, but pretty darn good for the biggest holiday weekend of summer. The weak ridge of high pressure floating overhead will keep us sunny and beautiful today with light winds, highs in the upper 70s to near 80. No complaints at all. Tomorrow an area of showers/storms over the Dakotas will brush far southwestern Minnesota, spreading high clouds into St. Cloud and the Twin Cities, dimming the sun, but any rain will probably stay south of the Minnesota River.
On Saturday, the 4th the sun should be out much of the day, but computer models are still hinting at a few PM showers and T-showers, most likely north/west of St. Cloud, toward Detroit Lakes, Cross Lakes and Bemidji – maybe some strong/severe storms up in the Red River Valley. The computer models keep much of central and southeastern Minnesota dry, with highs in the mid 70s to near 80 once again.
Sunday, the 5th, looks more unsettled, with more numerous showers and T-storms, affecting more than 50% of the state with a few hours of rain. The models print out .30 to .45″ of rain Sunday. Where it rains temperatures will hold in the low and mid 70s. Where the sun is out most of the day the mercury may hit 80, with more humidity, winds still fairly light on area lakes.
4th of July Weather Details
Friday: Partly sunny skies (high clouds dimming the sun by afternoon).
Percentage of Minnesota seeing rain: 15% (best chance far southwestern counties)
Highs: 77-81 (cooler south/west of the MN River, where clouds/showers will keep temperatures near 70)
Winds: NW 5-10.
Saturday (4th): Mix of clouds and sunshine. Clouds building in the afternoon, slightly higher humidity levels. Widely scattered showers/T-showers over western and northern MN by mid afternoon (best chance north/west of a line from Wheaton to Detroit Lakes, Cross Lake and Grand Rapids).
Percentage of Minnesota seeing rain: 25%
Highs: near 80 over most of central/southern Minnesota, mid 70s north, 5-8 degrees cooler where it does rain.
Winds: SE 5-10
Sunday: More clouds, unsettled, humid. More numerous/widespread showers and T-storms. The best chance of a few hours of rain should come during the afternoon/evening hours, when the atmosphere is most unstable.
Percentage of Minnesota seeing rain: 60% (rainfall amounts of .25 to .50″ possible)
Winds: light/variable, generally under 7 mph.