Thursday, May 27, 2010

5/27/10: Thursday's Weather Report

Issued at 2:58 PM CDT, Thursday, May 27th, 2010

Weather History:

On this date in 2008... A record low temperature of 31 degrees occurred at Duluth, MN.

Weather tidbits:

*Today marks the 13th day in a row with an above normal high temperature at Duluth, MN.

*12 out of the last 13 days has featured a maximum temperature of 70 degrees or higher at Duluth, MN.

*Average monthly temperature thru the 26th at Duluth, MN: 52.2 degrees which is 1.2 degrees Above Normal.

*2 days during the month of May has recorded a rainfall total >1.00" at Duluth, MN. 5/13/10: 1.03" and on 5/23/10: 3.96"

*The series of thunderstorms that tracked through Duluth, MN on Sunday May 23rd, 2010 dropped 3.96" of rain at the Duluth National Weather Service which erases the precipitation deficit that we were in prior to Sunday. All it took was a matter of an hour or so for a precipitation surplus to happen.

Precipitation total since 1/1/10: 9.15"
Normal: 8.10"
Departure: 1.05" Above Normal

Precipitation total since 3/1/10: 7.64"
Normal: 6.15"
Departure: 1.49" Above Normal

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

Another beautiful late Spring day across our local area with low humidity (dewpoints generally in the 40s to around 50 degrees) with Afternoon PWS ranging from 0.40"-0.60" across Northwest Wisconsin and Northeast-Eastern Minnesota, to 0.70"-0.90" in Northern Minnesota. High temperatures Today were in the mainly in the mid 70s to around 80 degrees with 60s close to Lake Superior. 850 mb temperatures as of 2 PM ranging from +10/+13 degrees C in Northern Minnesota and Northwest Wisconsin. Winds Today were out of the north, east, or west under 15 mph. Mostly sunny-sunny skies covered our local area Today with just some high level clouds moving across Northwest parts of our area. Surface map late Today featured high pressure of 1023 mb centered in Eastern Minnesota with a stationary front running west to east in Northern Minnesota while a cold front was centered over Central Lake Superior.

Today's 500 mb analysis:

Upper level ridge (582-588 meters) was re-developing from the Upper Midwest south through the Central Plains Today per RUC model analysis. Southwest H5 flow covered most of the Western U.S. Today with an upper level low (552-558 meters) in place over the Pacific Northwest. An axis of strong winds aloft (90-130 knots) extended from Central California northeast to Southwestern Montana late Today per RUC model analysis.

Tonight through Friday Night:

Little change in the weather is expected through this period with high pressure slowly pushing off to our east while the stationary front currently in Northern Minnesota sinks a little south Tonight and Friday before retreating back north as a warm front Friday Night. Mostly clear skies will be found across Northern Minnesota and Northwest Wisconsin Tonight and Tomorrow Night with partly cloudy-sunny skies on tap for Friday. Lows Tonight will be in the 40s and 50s, but some 30s are possible in the typical cold spots. Highs Tomorrow will be in the 70s and 80s with cooler temperatures near Lake Superior. Lows Tomorrow Night will be in the 40s and 50s. Variable winds will turn to the south/east Friday and Friday Night with wind speeds under 20 mph during this period.

Extended Forecast:

Saturday will be dry across our local area with high temperatures mainly in the 80s with a few locales possibly inching toward the 90 degree mark! It will be cooler though especially along the North Shore of Lake Superior. An area of low pressure will be tracking east-northeast across the Northern Plains on Saturday and will move into Central Canada or the Northern parts of Lake Superior (depending on the model) for Sunday Night and Monday. The forecast models Today are slowing the progression of this system with the EUROPEAN model the slowest of them all.

It now appears that the cold front will be tracking through Northern, Northeast, and Eastcentral Minnesota Sunday Afternoon-Evening with the cold front passing through Northwest Wisconsin Sunday Night.

The airmass along and ahead of this boundary will become somewhat moist and unstable this weekend with dewpoints climbing into the 50s-60s while H85 td's increase to +10/+14 degrees C with PWS of 1.00-1.30".

Instability will be on the rise as well for Sunday with CAPES generally around 1000 j/kg. Shear doesn't look too impressive at the moment with a weak low level jet in place <25 knots, strongest winds aloft are expected to remain post-frontal, with generally 25-35 knot 500 mb wind speeds found in Eastcentral Minnesota-Northwest Wisconsin Sunday Afternoon-Evening. There will, however, be a rather strong upper level jet edging east into Western Minnesota on Sunday with an area of 70-100 knot winds across the Northern Plains and adjacent areas of Western Minnesota late this weekend.

A few showers or thunderstorms could move into Northwest parts of our local area for Saturday Night with locations from International Falls to Northome, south to Cass Lake possibly seeing a few showers at that time.

The risk for showers or thunderstorms will then overspread the rest of our area Sunday and Sunday Night although right now it doesn't look like it'll be a steady all day rain, but any thunderstorm that develops could drop some heavier downpours. The risk for severe weather isn't the greatest, but an isolated severe storm could develop late Sunday Afternoon-Evening, mainly in Eastern Minnesota and Northwest Wisconsin based on the latest model projections.

Low temperatures Saturday Night will be in the 50s and 60s with highs Sunday in the 60s and 70s, but some 80s are possible mainly in Northwest Wisconsin. Lows Sunday Night will be in the 40s and 50s. High temperatures for Memorial Day will be in the 60s, but some Northern areas could hold in the 50s as a fairly strong push of cold advection (850 mb temperatures from -4/+2 degrees C) drops south behind Sunday's low/cold frontal passage Lows Monday Night will be in the 30s and 40s. The risk for a few showers will continue on Monday, especially in Northern Minnesota, the remainder of our area should be dry on Monday.

5 Day Forecast for Duluth/Superior

.Tonight... Mostly clear. Low 47 to 52. Wind east at 5 to 15 mph.

.Friday... Mostly sunny. High 75 to 80 but cooler near Lake Superior. Wind east to southeast at 10 to 15 mph.

.Friday Night... Mostly clear. Low 50 to 55. Wind east to southeast at 5 to 15 mph.

.Saturday... Partly cloudy. High 78 to 83.

.Saturday Night... Partly cloudy. Low 55 to 60.

.Sunday... Variable cloudiness. Showers or thunderstorms possible. High 70 to 75. Chance of rain 20%.

.Sunday Night... Partly to mostly cloudy. Showers possible. Low 45 to 50. Chance of rain 20%.

.Memorial Day... Partly sunny. High 60 to 65.

Normal High Temperature Today 67 degrees

Normal Low Temperature Today 44 degrees

Tim