Saturday, August 21, 2010

Foggy Start - Taste of July This Afternoon

* Dense fog this morning - shot at 90 degrees by late afternoon, more than 10 degrees warmer than average.

* Next chance of rain: Monday night (.25 to .50" rain possible, a few T-storms, nothing severe expected).

* Dry most of next week, comfortable midweek, feels like summer again by the end of next week.

* Some sun next Saturday (probably the drier day of the weekend). Heavier, steadier rain possible a week from today, first 2 days of September may be very wet across much of Minnesota.

Dense Fog Advisory. More thick fog is possible Sunday morning, the combination of relatively light winds, residual moisture (dew points in the 60s) and longer nights producing ripe conditions for fog. For the latest warnings, watches and advisories check out this map from Ham Weather, a division of WeatherNation.

18 Year Anniversary of "Andrew." Hurricane Andrew was the third most powerful category 5 hurricane ever observed in the Atlantic, producing wind gusts clocked as high as 212 mph before it slammed into the Miami area on August 22, 1992. Damage estimates ranged from $27 to 34 billion, the second most expensive hurricane in U.S. history (second only to Katrina). It also had the rare distinction of hitting the U.S. twice, making landfall just south of Miami, and then 2 days later slamming into coastal Louisiana. Good summaries of Hurricane Andrew are here and here.

The thing about trying to predict Minnesota's weather? It's not an 8 to 5 gig. You LIVE the weather, 24/7 - constantly running to the window ("why the BLEEP is it still foggy?") - you're perpetually stressed that the forecast will work out the way you said it would. ESPECIALLY on a weekend, one of the last weekends of a fleeting Minnesota summer. You can get away with a busted forecast on a Tuesday, when people are stuck in an office cubicle or at class - but on a Saturday or Sunday Minnesotans quickly lose their sense of humor when the forecast doesn't work out as planned.

Fog Season. Saturday morning's stubborn fog was the result of a). significant summer moisture, dew points near 70 and b). longer nights, allowing the temperature to fall to the dew point (creating a relative humidity of 100% - saturating the atmosphere, creating a cloud on the ground, better known as fog). Dense fog advisories were issued along Lake Superior's North Shore and across parts of western Minnesota. Graphic courtesy of the National Weather Service, which has more on Saturday's dense fog here.

Lake Effect. Water temperatures are still quite mild (most Minnesota lakes reporting readings between 68-74 F) but midday temperatures on Saturday were several degrees warmer over land. The result: cumulus and stratus clouds over land, but clear regions over Minnesota's lakes, extending several miles downwind.

"Hey dad, you said the sun would be out, what's up with that?" my oldest son, Walt, scolded Saturday morning. I was staring out the window, willing the fog and low (stratus) clouds to magically part. "Patience butterfly." The sun should be strong enough to burn this stuff away by midday. "But you PROMISED", he insisted, holding up the newspaper to remind me what I had predicted. Thanks for your faith in your old man. Yes, we've lost about 110 minutes of daylight since June 21, the Summer Solstice. The sun is now as high in the sky as it was back on April 22, believe it or not. Those low clouds can be a lot more stubborn than they are in July - it takes a few extra hours for the atmosphere to warm up (and mix up) sufficiently for the fog to burn away, but I may have been the happiest guy in Minnesota to see the sun FINALLY break through yesterday afternoon - and it did mellow into a marvelous Saturday statewide.

Saturday Stats. Even with the persistent morning fog and low cloud cover the mercury reached 84 at St. Cloud, 85 in the Twin Cities and Alexandria, a respectable 88 at Redwood Falls. Tell that to shell-shocked residents of Grand Marais, where the "high" was a meager 58, the result of a strong breeze off Lake Superior.

Paul's Conservation MN Outlook for the Twin Cities and all of Minnesota

Today: Foggy start, then sunny and very warm during the afternoon hours. Winds: SE 10-20. High: near 90 (if the fog lingers through midday we may only hit 86-88 F).

Sunday night: Clear and mild. Low: 68

Monday: Warm sunshine, windy. Showers and T-storms likely Monday night. High: 88

Tuesday: Damp start, then partly sunny, breezy and less humid. High: 78

Wednesday: Mostly sunny and comfortable (less wind). High: 77

Thursday: Blue sky, still very pleasant. High: near 80

Friday: Hazy sun, warming up again. High: 85

Saturday: Fading sun, growing chance of a shower or T-shower. High: 84

Today will bring back (good) memories of mid July: more fog early should burn off by 10 or 11 am, with enough hazy afternoon sunshine for highs in the upper 80s to near 90. Expect a bit more wind, blowing from the southeast at 10-20, a bit more chop on area lakes. Monday will be nearly as warm, highs well up in the 80s, winds gusting to 25+ mph from the south before an eastbound cool front arrives with showers and a few embedded T-storms Monday night. After a damp start the sun comes out Tuesday, winds swing around to the northwest, dew points drop through the 60s and 50s - by Wednesday it will feel like mid September with highs in the 70s and dew points dipping into the 40s - fresh air!

Next week looks mostly-dry, no rain expected between Tuesday and Friday, only a slight chance of a shower or T-shower by next Saturday (which right now appears to be the better day of the weekend). Computer models are hinting that next Saturday's cool front will stall nearby, sparking a more significant period of rain next Sunday and Monday. Roughly 1 week out we may be faced with some .5 to 1"+ rainfall amounts, but that's way out on the horizon. If you want to have a sunny (dry/pleasant) State Fair experience consider heading out Thursday or Friday - all bets are off next weekend, especially Sunday.

Oxford, Michigan "Supercell." Check out this YouTube footage of a rare, rotating "supercell" thunderstorm that went on to spawn large hail, even a few tornadoes near Motor City.

* 2 Tornadoes Touch Down North of Detroit. In the "say what?" department, check out this head-scratcher from Michigan. Big tornadoes near Detroit, in late August? Unusual to say the least.

Earthweek. For a good update on what's happening around the planet, click on "Earthweek". From vampire bat attacks in South America to swarms of locust in Australia to earthquakes in Italy - some eye-opening reports from the front lines here.

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