Wednesday, June 1, 2011

6/1/11: Wednesday's Weather Report

Issued at 4:57 PM CDT, Wednesday, June 1st, 2011

EF-0 TORNADO IN LAKE COUNTY MINNESOTA.  Source:  NWS Duluth, MN.

On Saturday, May 28th, 2011 an EF-0 tornado occurred in Southern Lake county in Northeastern Minnesota.

Location:  7.66 miles northeast of Wales Minnesota to 8.80 miles south of Whyte, Minnesota.
Estimated time:  3:07 PM-3:10 PM CDT
Path length:  1.9 miles
Max width:  350 yards
Rating:  EF-0 with estimated winds of 70-80 mph

Note:  This was the first tornado since September 16th, 1992 to touch down in Lake county, MN.

May 2011 Climate Data for some Minnesota cities:  Source NWS Duluth, MN.

Minneapolis, MN:

Average monthly temperature:  58.4 degrees/0.9 degrees below average
Precipitation total:  4.40"/0.80" above average

St. Cloud, MN:

Average monthly temperature:  55.6 degrees/0.9 degrees below average
Precipitation total:  5.51"/2.54" above average

International Falls, MN:

Average monthly temperature:  50.9 degrees/2.4 degrees below average
Precipitation total:  1.84"/0.71" below average

Duluth, MN:

Average monthly temperature:  49.7 degrees/2.1 degrees below average
Precipitation total:  2.27"/0.68" below average

June climate normals for Duluth, Minnesota:

Average high on the 1st:  68 degrees
Average high on the 30th:  74 degrees

Average low on the 1st:  45 degrees
Average low on the 30th:  52 degrees

Average precipitation:  4.25"
Average temperature:  59.9 degrees

The outlook for June:

40% chance for below average temperatures
50% chance for above average precipitation

WEATHER HEADLINES:

-Scattered frost threat late Tonight
-Scattered shower/thunderstorm chances return Thursday and Friday
-Isolated severe thunderstorm risk mainly Thursday Night/Friday?

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Deep low pressure of 996mb has moved into Eastern Canada with a ridge of high pressure averaging 1022mb passing through the Upper Midwest while the next system with a 1004-1008mb low heads into the Central Rockies.  Clouds wrapping around the system in Eastern Canada continued to affect portions of our area Today, most notably for locations north of Highway 2.  A swath of mostly sunny skies were found in Central Minnesota through Northern Wisconsin while the Rocky Mountain storm was beginning to push some clouds east out of South Dakota late Today.  High temperatures Today ranged from around 60 in the Arrowhead and far Northern Minnesota with 60s to lower 70s for the rest of us.  Winds were out of the northwest at 10-20 mph, but stronger gusts over 30 mph did occur for much of the day, especially near Lake Superior.

Today's Upper Level Analysis:

500mb troughs were found in Eastern Canada and west of the Rockies while an upper level ridge and W-SW H5 flow moves east out of the Northern Plains per RUC model analysis and water vapor satellite imagery.  The system out west is quite potent with a 120 knot speed max centered in Northern Nevada while a 110 knot upper level jet stretched from Northern Minnesota and the Upper Great Lakes to Southern Quebec Province per RUC model analysis.

Tonight:

Ridge of high pressure will be over our area most of the Evening, but it will start to push off toward the east Overnight.  Clear to partly cloudy skies with diminishing winds will allow temperatures in Northeast Minnesota to fall into the 30s with a few 20s even possible in the typical cold spots, areas of frost are expected Overnight and a *FROST ADVISORY* is in effect from 1 AM  to 7 AM CDT Thursday for Northern and Central St. Louis...Northern Lake...and Northern Cook counties in Northeast Minnesota.  Some cities included in the advisory are:  Crane Lake MN...Ely MN...Hibbing MN...Cotton MN...and Isabella MN.  Low temperatures for the remainder of our area will be in the 30s and 40s.  Winds Tonight will become easterly under 15 mph.

Thursday and Thursday Night:

High pressure will be centered to our east while low pressure heads into the Western High Plains.  Warm front attached to that low will extend northwest to southeast from Central North Dakota to Southern Minnesota.  Strong warm and moist advection pattern will occur during this period with PWS climbing to between 1.00-1.50" with 850mb td's of +8 to +14 degrees C.  Surface dewpoints will reach the 50s away from Lake Superior with a few 60s even possible toward the Brainerd Lakes area.  A strengthening southerly low level jet of 40-55 knots will develop out ahead of this system and this combined with increasing amounts of elevated instability with MU CAPES of 500-1500 j/kg will give way to scattered showers and thunderstorms in our area for Tomorrow and Tomorrow Night...But, the greater risk for thunderstorms may actually hold off until Thursday Evening/Overnight when the better instability makes it up this way.  Winds in the mid and upper levels will be quite strong across the Upper Midwest and this plus favorable shear in place could result in a few severe thunderstorms Thursday night with large hail the main threat due to a cap which is forecast to spread E-NE out of the Western High Plains...This layer of warm air aloft should prevent surface based thunderstorm development.  Highs Tomorrow will be in the 50s and 60s with 40s near Lake Superior.  Lows Tomorrow Night will be in the 40s and 50s.  Winds during this period will be out of the east or southeast at 10-20 mph with a few higher gusts.

Extended Forecast:

Friday, June 3rd:  Strong low pressure will pass well to the northwest of Minnesota, although there will be a secondary low that will track E-NE through the Upper Midwest.  A warm front will push east through Northern Wisconsin on Friday with a cold front dropping E-SE across our area Friday Afternoon/Evening.  Very warm temperatures consisting of 850mb temperatures > +20 degrees C and 700mb temperatures of +12 to +14 degrees C will be found in our area on Friday and this should cap off the atmosphere meaning that any thunderstorm that may develop should remain elevated with the potential for some large hail.  Based on latest model data it would appear that the greatest risk for a few showers and thunderstorms for Friday and Friday Evening would be in Northwest Wisconsin and Eastern Minnesota with mainly dry conditions for Northern Minnesota.  Highs on Friday will be in the 70s and 80s but it will be cooler near Lake Superior.  Lows Friday Night will be in the 50s.

Note:  Dewpoints will climb into the 60s in Northwest Wisconsin and Eastern Minnesota on Friday with PWS over 1.00"

Saturday, June 4th:  Mild temperatures with less humidity can be expected as a cold front exits to our south/east with a drier westerly wind developing in it's wake.  Highs will be in the 60s and 70s with lows in the 40s to lower 50s.

5 DAY FORECAST FOR DULUTH/SUPERIOR

.Tonight...  Mostly clear.  Low 40 to 45.  Wind becoming east to northeast at 5 to 15 mph.

.Thursday...  Considerable cloudiness.  Breezy.  Scattered showers mainly during the Afternoon.  High 58 to 63 but cooler near Lake Superior.  Wind east at 10 to 20 mph.

.Thursday Night...  Scattered showers or thunderstorms.  Mostly cloudy.  Low 45 to 50.  Wind east at 10 to 20 mph.

.Friday...  A few showers or thunderstorms.  Partly sunny.  High 60 to 65 but cooler near Lake Superior.

.Friday Night...  Becoming partly cloudy.  Low 50 to 55.

.Saturday...  Partly cloudy.  High 70 to 75.

.Saturday Night...  Partly to mostly cloudy.  Low 48 to 53.

.Sunday...  Partly sunny.  High 67 to 72.

Normal temperatures for Tomorrow

High:  68 degrees
Low:  45 degrees

Sunrise Tomorrow:  5:18 AM CDT
Sunset Tomorrow:   8:56 PM CDT

Thursday's Pollen Forecast

Tree:    None
Grass:  None
Weed:  None

Duluth/Superior Harbor water temperature as of June 1st:  45.5 degrees

Tim