Tuesday, June 15, 2010

6/15/10: Tuesday's Weather Report

Issued at 3:12 PM CDT, Tuesday, June 15th, 2010

Weather History:

On this date in 1989... A record low temperature of 35 degrees occurred at Duluth, MN.

Here are some rainfall totals across Northern Minnesota and Northwest Wisconsin from 7 AM CDT Monday through 7 AM CDT Today... Source: NWS Duluth, MN.

Duluth MN: 0.23"

Hayward WI: 0.22"

Cass Lake MN: 0.50"

Bruno MN: 0.27"

Dixon Lake MN: 0.37"

Floodwood MN: 0.15"

Hinckley MN: 0.27"

Butternut WI: 0.20"

Sarona WI: 0.18"

Weather tidbits for Duluth, MN...

*Average Monthly temperature through the 14th: 56.0 degrees
Departure: 2.0 degrees Below Normal

*Precipitation total through the 14th: 2.85"
Departure: 0.97" Above Normal

*12/15 days so far in June has had at least a trace of rainfall.

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

It's been a fairly wet day across our local area thanks to a surface and upper level low pressure system which has been moving east through the Upper Midwest Today. Cold temperatures aloft (-14/-15 degree C 500 mb temperatures) combined with some instability with Afternoon CAPES around 500 j/kg and most unstable Lifted Indices from -1/-6 degrees C has been helping to trigger scattered showers and thunderstorms around parts of our area Today. The main threats out of these storms so far Today has been very heavy downpours and dangerous lightning strikes. High temperatures were mainly in the 60s across Northern Minnesota and Northwest Wisconsin Today with 50s near Lake Superior. 850 mb temperatures as of 3 PM ranged from +9/+12 degrees C. Winds Today were out of the south, east, or north generally under 20 mph.

Today's 500 mb analysis:

(570 meter) upper level low was centered in Westcentral Minnesota This Afternoon per water vapor satellite imagery with movement toward the east. A southwest flow aloft continued Today across the Great Lakes out ahead of this system. Upper level ridging was moving into the Northern Plains This Afternoon per RUC model analysis while another strong upper level trough digs south/east through Western Canada and the Pacific Northwest Today.

Tonight:

Scattered showers and thunderstorms will continue through the Evening hours across Northern-Eastern Minnesota and Northwest Wisconsin. Heavy rain and occasional lightning strikes will be the main hazards from these storms with localized flooding possible especially from Brainerd and Moose Lake down through Hinckley and Pine City and also affecting portions of Northwest Wisconsin, mainly west of a line from Port Wing to Shell Lake.

...CONCERNING TONIGHT'S SEVERE RISK...

There is also an isolated risk for severe thunderstorms through 7 PM CDT This Evening for Pine, Carlton, Southern Aitkin Counties in Eastcentral Minnesota and for Burnett and Douglas Counties in Northwest Wisconsin. Hail to 1" in diameter and damaging wind gusts to 60 mph are possible, there is also a threat for an isolated tornado in these same areas due to the added vorticity near the path of the surface and upper level low early This Evening. 0-1 KM and 0-3 KM Helicities up to 100 m2/s2 was in place in Eastern Minnesota/far Northwest Wisconsin late Today per SPC meso-analysis which is certainly enough in this type of pattern to cause brief tornadoes.

Mostly cloudy skies are expected across all of our area Tonight with areas of fog which could be dense, the threat for rain will end by late Evening across our entire area as the surface/upper low exit to our east. Lows Tonight will be in the 40s and 50s with winds out of the north, west, or east under 15 mph.

Wednesday and Wednesday Night:

A brief break from all the crummy weather as of late will take place during this period as an upper level ridge of high pressure passes east through the Upper Midwest. Areas of fog which could be dense early Tomorrow Morning will give way to partly-mostly sunny skies across Northern Minnesota and Northwest Wisconsin on Wednesday with highs in the 60s and 70s. Partly-mostly cloudy skies with lows mainly in the 50s are expected Tomorrow Night. Winds Tomorrow will be out of the south, east, or north under 15 mph. Winds Tomorrow Night will be out of the south or east under 15 mph.

Extended Forecast:

A strong area of low pressure averaging 992 mb is forecast to move northeast across the Northern Rockies/Northern Plains on Thursday, which will then pass by to our northwest-north on Friday. A warm front and cold front which will have (some dry-line characteristics) will surge N/NE through all of our area from late Thursday through Friday Morning. A 30-45 knot S/SE 850 mb jet is forecast to be in place out ahead of this system on Thursday which will bring higher amounts of humidity north into our area. By Thursday Afternoon/Evening, dewpoints will be in the 60s with PWS increasing to between 1.25"-1.75" while 850 mb td's climb to between +10/+15 degrees C.

...CONCERNING THURSDAY'S SEVERE RISK...

The latest set of forecast models continue to show ample instability developing around our area Thursday/Thursday Evening with CAPES ranging from 1000-2500 j/kg with Lifted Indices of -2/-5 degrees C.

S/SE winds at 850 mb with more of a SE wind at the surface combined with a SW wind at 500 mb will also be in place and this combined with around 30-40 knots of 0-6 KM Bulk Shear and Effective Bulk Shear along with Helicities around 150m2/s2-300 m2/s2 could lead to the development of severe weather Thursday Afternoon or Thursday Evening.

There still appears to be a risk for isolated tornado development late Thursday Afternoon-Evening...(5PM-9PM time range) in the Southern parts of our area...Including Pine, Southern Aitkin, and Crow Wing Counties in Eastcentral Minnesota, then south through the Interstate 94 corridor in Central Minnesota.

Large hail and damaging winds will also be possible across our area with any severe thunderstorm that develops Thursday Afternoon-Thursday Evening.

High temperatures on Thursday will be in the 70s and 80s but it will be cooler near Lake Superior. Lows Thursday Night will be in the 50s and 60s.

Friday will be a windy day across our area as winds swing around to the southwest with gusts up to 35 mph possible. Deep low pressure will be tracking through Central Canada on Friday with a cold front attached to that low pushing east out of Northwest Wisconsin and the Arrowhead of Minnesota Friday Morning. High temperatures on Friday will be in the 70s and 80s...even near Lake Superior thanks to the strong off-shore wind that will develop. Lows Friday Night will be in the 50s to lower 60s.

5 Day Forecast for Duluth/Superior

.Tonight... Overcast with areas of fog and drizzle. The fog could be dense at times. Scattered showers and a possible thunderstorm through 9 PM. Low 48 to 53. Wind east to northeast at 5 to 15 mph.

.Wednesday... Areas of dense fog early, otherwise partly to mostly sunny. High 68 to 73 but cooler at times near Lake Superior. Wind north at 5 to 15 mph.

.Wednesday Night... Partly cloudy. Low 50 to 55. Wind east to southeast at 5 to 15 mph.

.Thursday... Showers or thunderstorms possible. Partly sunny. High 67 to 72 but cooler near Lake Superior. Chance of rain 30%.

.Thursday Night... Showers or thunderstorms possible. Variable cloudiness. Low 50 to 55. Chance of rain 30%.

.Friday... Windy and warmer. Showers or thunderstorms possible early. Partly cloudy. High 80 to 85. Southwest winds could occasionally gust to 30 mph.

.Friday Night... Mostly clear. Low 55 to 60.

.Saturday... Partly cloudy. High 73 to 78.

Normal High Temperature Today 71 degrees

Normal Low Temperature Today 48 degrees

Tim