Issued at 3:28 PM CDT, Monday, June 18th, 2012
Tonight: A few showers/t’storms early in far NE MN and again Overnight in Southern areas.
Tuesday: Huge temperature gradient. Showers/t’storms. (Heavy rain/severe threat)
Wednesday: Lingering showers/t’storms.
-15z SREF significant tornado forecast for late Tuesday Afternoon. A value of 1 is considered high enough for tornadoes. Late Tuesday, there are values of 2 to 4 in parts of Central/Eastern MN and Northern Wisconsin. Extremely high numbers for tornadoes. Lots of questions remain, however, capping issues, the placement of the warm front, will skies clear for a bit, will storms stay elevated (no tornado threat) or can they become surface-based (higher chance for tornadoes) More details below.
Rainfall report for June 17th, 2012
Source: National Weather Service Duluth, Minnesota
Duluth, MN: 0.71″
Brainerd, MN: 0.32″
Grand Marais, MN: 0.44″
Hibbing, MN: 0.38″
Ashland, WI: 0.69″
Hayward, WI: 0.21″
Butternut, WI: 1.32″
Gile, WI: 0.50″
Gurney, WI: 0.89″
Embarrass, MN: 0.28″
-Rainfall map for June 17, 2012.
Weather Tidbits:
*88 severe weather reports in the U.S. on Sunday with the bulk of the reports in Minnesota and Eastern South Dakota (SPC)
*2 tornadoes in Western Minnesota on June 17th, 2012*
6:52pm: 5 E of Wheaton, MN (Traverse County)
6:52pm: 11 NE of Wheaton, MN (Traverse County)
-Storm reports map from Sunday per SPC.
red dots=tornado reports
blue dots=damaging wind reports
green dots=large hail reports
Weather History:
On this date in 1995: A record high temperature of 94 degrees occurred at Duluth, MN.
Today’s Weather Summary for Northeast Minnesota and Northwest Wisconsin
Low pressure of 994mb was over Southwest Ontario as of 3pm. A cold front extended from far Northeast Minnesota to Western Wisconsin to Western Iowa. Numerous supercell thunderstorms erupted Today in far Northern St. Louis County in Northeast Minnesota, these supercells extended into Southern Ontario. Several severe thunderstorm warnings have been issued This Afternoon by the NWS, even had 1 tornado warning around 2pm Today. The setup for severe weather is a good one with wind shear on the order of 50-70 knots in the Arrowhead with CAPE around 1500 j/kg. The area that saw the severe storms was very small, however, as the rest of our area stayed generally dry Today with just a few brief showers in spots. Highs Today were in the 70s with middle 80s from Siren and Hayward, east to Park Falls. Dewpoints were in the 50s and 60s and winds were out of the south, west or east at 5 to 15 mph.
-GR3 radar image from earlier This Afternoon when a tornado warning was issued for a small part of Northern St. Louis County in Northeast Minnesota. This was a doppler radar indicated tornado.
-Doppler radar velocity at the time the tornado warning was in effect. This supercell had broad rotation, but didn’t tighten up enough to put down a tornado.
Today’s Upper Level Analysis:
A west-southwest mid/upper level flow was in place across the Upper Midwest per water vapor satellite imagery. Unusually strong jet stream winds continued Today with wind speeds from 110-130 knots stretching from the Pacific Northwest to Northwestern Minnesota per RAP model analysis. An upper level trough was digging S/SE through the Northwest U.S. with height falls of 60-90 meters. 850mb temperatures as of 2pm ranged from +8 to +14C in Northern Minnesota to +16 to +20C in Central and Southern Minnesota.
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
Tonight (June 18th)
Isolated strong to severe thunderstorms will be possible in extreme Northeast Minnesota, affecting parts of Northern St. Louis, Northern Lake, and Northern Cook Counties. Hail and strong winds would be the main hazards if severe weather develops thru 7pm. The rest of our area, as well as the Arrowhead will then have a period of dry weather during the Evening hours.
By late Tonight, scattered showers and thunderstorms should begin to redevelop, mainly along and south of Highway 2 as warm and moist air begins to lift back to the north. The cold front analyzed in Western Wisconsin and Iowa will stall out and turn into a warm front Tonight, this boundary will make it into the Southern half of Minnesota by dawn.
Partly to mostly cloudy skies are expected Tonight with lows in the 50s and 60s. Winds will be out of the southwest, north, or northeast at 5 to 15 mph.
-Tonight’s low temperature forecast
Tuesday and Tuesday Night (June 19th)
***Heavy rain and severe weather possible during this period***
A deep area of low pressure will move out of Nebraska and into Westcentral Minnesota while a warm front lifts north into Central Minnesota and Northern Wisconsin with a cold front moving east out of the Dakotas. Very strong winds aloft on the order of 90-110 knots in the upper levels with a 75 knot mid level jet streak across the Northern Plains will provide a good deal of lift throughout our area, this combined with the approaching low, warm front, and cold front should result in multiple waves of showers and thunderstorms in the Northland.
-Deep moisture will surge north on Tuesday with dewpoints reaching the 60s and 70s away from Lake Superior with 850mb dewpoints from +12 to +18C and PWS of 1.50-2.00″. With all this moisture in place, the potential is certainly there for very heavy rainfall amounts which could lead to some flash flooding.
-Severe thunderstorms are also possible, although much of the instability looks to be elevated in our area with CAPE from 1000-2500 j/kg with Lifted Indices of -3 to -8C. Large hail and damaging winds appear to be the main hazards if storms become severe.
-An isolated risk for tornadoes is also possible, from the Brainerd Lakes, Hinckley and Pine City areas in Eastcentral Minnesota, into Northwest Wisconsin…These areas stand the best chance for seeing surface-based thunderstorm development later in the day, but there will also be a warm layer of air in the mid levels with 700mb temperatures around +12C and 850mb temperatures of +20 to +24C…This could keep the tornadic threat at bay, instead thunderstorms wouldn’t develop until after sunset Tuesday, once the temperatures aloft cool enough.
-There should be a tremendous amount of wind shear over our area on Tuesday with Effective Bulk Shear and 0-6 KM Shear of 40-60 knots. 1 KM Helicity near the warm front should be around 200 m2/s2 which certainly warrants a tornado risk, if the cap can weaken before sunset.
-If you live in Northeast Minnesota and Northwest Wisconsin you may wanna keep a close eye on the weather Tuesday and Tuesday Night. There’s a threat for flash flooding as well as some strong to severe thunderstorms. Elevated supercells with a hail and high wind threat could develop with at least a small chance for tornadic supercells for southern parts of our area from Brainerd to Hinckley, east into Northwest Wisconsin.
Highs Tomorrow will range widely with 50s and 60s in Northern Minnesota and near Lake Superior with 80s and maybe even a few 90s in Southern areas. Lows Tomorrow Night will be in the 60s and 70s with 50s near Lake Superior. Winds during this period will be out of the south, north, or east at 10 to 20 mph.
-15z SREF calibrated severe weather probability forecast for late Tuesday Afternoon. Maxed out numbers showing up from Southwest to Eastern MN, including far Northwest Wisconsin.
-Storm Prediction Center has all of Northwest Wisconsin and the Southern parts of the Northland, including Duluth and Superior in a Slight Risk for severe thunderstorms Tuesday and Tuesday Night.
-12z Hi-Res NAM rainfall forecast for Tuesday and Wednesday. This model run really hits Northern Minnesota with a lot of rain! Perhaps 3-6″+ Note: It’s tough for the models to pin down the exact location where thunderstorms will setup and train over and over again…Thus the axis of heaviest rain could shift somewhat more to the south than what this model is showing. Stay tuned!
-Tuesday’s high temperature forecast
-HPC’s rainfall forecast valid thru 7pm Tuesday
-HPC’s rainfall forecast valid from 7pm Tuesday thru 7pm Wednesday.
-Surface map for 7pm Tuesday per HPC. Always get concerned when you see a boundary stall out with hot/very unstable and humid airmass south of the front lifting up and over the surface boundary in Central Minnesota.
Extended Forecast, Wednesday-Friday (June 20th-22nd)
Wednesday: A cold front will continue to move east and should exit our area later in the day. Showers or thunderstorms are possible during the day with dry weather moving in for Wednesday Night. Highs will be in the 60s and 70s with lows in the 40s and 50s.
Thursday: Could see a few pop-up showers or thunderstorms in the Northland on Thursday with dry weather Thursday Night. Highs will mainly be in the 70s with lows in the 50s.
Friday: Dry with highs mainly in the 70s.
Long Range Forecast (June 23rd-29th)
A low pressure disturbance could track west-south of our area on Saturday (23rd) this system could bring some showers or thunderstorms to parts of the Upper Midwest. The remainder of this period should be controlled by a west or west-northwest upper level flow, this type of pattern can be unsettled at times as disturbances drop southeast out of the Northern Rockies. Any of those disturbances could spark off a round of showers and thunderstorms. Temperatures will be near normal levels during this period.
5 DAY FORECAST FOR DULUTH/SUPERIOR
*Flash Flood Watch*
Valid: Tuesday Afternoon until Wednesday Afternoon.
.Tonight… Partly cloudy This Evening. Becoming mostly cloudy Overnight. Scattered showers or thunderstorms possible after Midnight. Low 59 to 64. Wind west to southwest at 10 to 20 mph, becoming east at 5 to 15 mph late. Chance of rain 40%.
.Tuesday… Occasional showers or thunderstorms. Locally heavy rain possible. High 64 to 69 but in the 50s near Lake Superior. Wind east at 10 to 20 mph. Chance of rain 70%.
.Tuesday Night… Occasional showers or thunderstorms. Locally heavy rain possible. Low 55 to 60. Wind east at 10 to 15 mph, becoming southwest. Chance of rain 70%.
.Wednesday… Considerable cloudiness. Showers possible. High 65 to 70. Chance of rain 40%.
.Wednesday Night… Partly to mostly cloudy. Low 50 to 55.
.Thursday… Partly cloudy. High 70 to 75.
.Thursday Night… Partly cloudy. Low 50 to 55.
.Friday… Partly cloudy. High 70 to 75.
Normal temperatures for Today
High: 72
Low: 50
Sunrise Tuesday: 5:14 AM CDT
Sunset Tuesday: 9:06 PM CDT
Tim
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