Friday, April 29, 2011

4/29/11: Friday's Weather Report

Issued at 4:22 PM CDT, Friday, April 29th, 2011

Weather tidbits:  Source:  TWC.  Paul Douglas/St. Cloud Times

-Preliminary tornado count from Wednesday April 27th, 2011 is up to 211
-Death toll from Wednesday's historic tornado outbreak is up to 318 which surpasses the 307 fatalities from the Super Outbreak of 1974
-The tornado that hit Tuscaloosa, Alabama late Wednesday Afternoon may have been on the ground for 200 continuous miles! The all time record is 219 continuous miles during the Tri State tornado outbreak of 1925 which resulted in over 600 deaths

Above average tornado season ahead for Minnesota?

Source:  NWS and Paul Douglas/St. Cloud Times

An April that finished in the top ten for most tornadoes in the country has led to an above average season for both Minnesota and Wisconsin in 6 of those 10 years.

In years with La Nina (cooler than normal waters in the Eastern Pacific) of similar strength and a similar trend of gradual waning had an equal amount of active and non-active tornado seasons for Minnesota and Wisconsin.

*2.5 magnitude earthquake early This Morning at Alexandria, Minnesota.  This earthquake happened at 2:20 AM CDT This Morning, Friday, April 29th, 2011.  Source:  USGS

Distance from the epicenter of the earthquake from a few other Minnesota cities:

39 miles southeast of Fergus Falls, Minnesota
55 miles north-northwest of Willmar, Minnesota
127 miles west-northwest of St. Paul, Minnesota

Precipitation update for Duluth, Minnesota for April 2011, thru the 29th:

Total precipitation:  2.68"
Departure from average:  +0.75"

21 days have had at least a trace of precipitation.  15 days have had at least a trace of snow.

Note:  3 day precipitation total at Duluth, MN (April 26th-29th, 2011)  0.64" with 1.2" of snow

Weather headlines:

-Clouds increase Tonight, rain threat goes up Overnight
-Rainy Saturday ahead
-Isolated thunderstorm risk late Tonight thru Saturday
-Windy and colder Saturday Night and Sunday
-Frozen precipitation possible for Northern Minnesota late this weekend?

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

High pressure pushed off to our east Today with low pressure of 992-994mb stretching from the Northern Plains to Central Plains.  Broad southerly flow was occurring in our area behind the high and east of the low.  Temperatures Today were above average in most areas with highs in the 60s, but a lake wind kept temperatures in the 40s and 50s near Lake Superior.  Partly cloudy to sunny skies covered our area Today with south or east winds at 10-20 mph with a few higher gusts.  Note:  Temperatures This Afternoon were in the middle 70s as far north as Eastern Nebraska with 90 degree temperatures in extreme Southwest Kansas with low 100s in Northwest Mexico.

Today's Upper Level Analysis:

500mb trough was digging south across the Northcentral Rockies per water vapor satellite imagery with an area of 60-90 meter 12 hour H5 height falls accompanying this latest storm.  Southwest flow aloft was in place across the Upper Midwest Today out ahead of this storm with an upper level ridge pulling off to our east late Today.

Tonight:

Low pressure of around 995mb will be centered to our west.  A strengthening low level jet from the south of 50-65 knots will lead to a warm/moist advection pattern in our area.  Late Afternoon PWS around 1/4" will increase to 0.75" Overnight.  Look for showers to become more widespread late Tonight due to the low level jet, warm/moist advection pattern.  Isolated thunderstorms are also possible with elevated CAPE at or below 100 j/kg.  Lows Tonight will be in the 40s, but some 30s are expected near Lake Superior.  Winds will be out of the south or east at 10-25 mph.

Saturday:

Deep low pressure of around 994mb will lift through the Eastern Dakotas/Northwestern Minnesota.  Southerly winds and a strong low level jet of 40-65 knots will continue ahead of this low on Saturday with plenty of moisture in place with PWS around 0.75" and dewpoints in the 40s.  A strong cold front attached to this low will swing northeast and through our local area Tomorrow while a potent disturbance moves east out of the Dakotas.  Rain looks to be fairly widespread in Northern Minnesota and Northwest Wisconsin on Saturday with isolated thunderstorms possible as well, especially during the Afternoon as a dry slot surges E-NE out of Western Minnesota.  Latest forecast models indicate that CAPE values will increase to around 100-200 j/kg Saturday Afternoon which combined with the strength of this system would allow a few thunderstorms to fire up, this threat would only increase if we get some some sunshine Saturday Afternoon, but that potential continues to look low.  Note:  Another weather problem on Saturday may be the formation of some fog near Lake Superior.  Mostly cloudy skies are forecast Tomorrow with highs in the 40s and 50s.  Winds will be out of the south, east, or southwest at 10-25 mph.

Note:  Total rainfall amounts of 0.25"-0.50" can be expected in Northern Minnesota and Northwest Wisconsin late Tonight through Saturday with localized greater amounts approaching 0.75".

The same storm which will give us rain Tonight and Saturday will produce heavy snow and blizzard conditions Saturday into early Sunday in parts of North Dakota with snowfall accumulations possibly exceeding 6" in some areas.

Saturday Night:

Low pressure of around 993mb will reach Western Ontario Province with a strong cold front exiting our area to the east.  Strong cold air advection will kick in behind the low and cold front as 850mb temperatures tumble to -4 to -12 degrees C.  Variably cloudy skies are expected Tomorrow Night with a few rain showers which could mix with or turn to snow showers in Northern Minnesota late Tomorrow Night.  Lows Saturday Night will be in the 20s and 30s with southwest or west winds at 15-30 mph.

Extended Forecast:

Strong low pressure will track through Central Canada on Sunday with a continued threat for lingering rain and or snow showers for Northern Minnesota and Northwest Wisconsin.  Highs on Sunday will only reach the 30s and 40s.  Clearing skies can be expected Sunday Night with lows in the 20s to lower 30s.  Dry weather is in the forecast for Monday, May 2nd with highs in the 40s and 50s with lows Monday Night in the 20s and 30s.

5 Day Forecast for Duluth/Superior

.Tonight...  Increasing cloudiness.  Occasional showers after 3 AM.  Low 38 to 43.  Wind east to southeast at 10 to 20 mph.

.Saturday...  Occasional rain.  Isolated thunderstorms also possible during the Afternoon.  Mostly cloudy with areas of fog.  High 45 to 50 but cooler near Lake Superior.  Wind east to southeast at 10 to 20 mph becoming south away from Lake Superior.

.Saturday Night...  Breezy.  Considerable cloudiness.  A few rain showers possible.  Low 30 to 35.  Wind southwest at 15 to 30 mph.

.Sunday...  Breezy.  Partly sunny.  High 40 to 45.

.Sunday Night...  Mostly clear.  Low 27 to 32.

.Monday...  Partly cloudy.  High 50 to 55.

.Monday Night...  Partly cloudy.  Low 30 to 35.

.Tuesday...  Partly cloudy.  High 55 to 60.

Normal temperatures for Today

High:  56
Low:  34

Sunrise Tomorrow:  5:56 AM CDT
Sunset Tomorrow:   8:17 PM CDT

Tim