Issued at 12:51 PM CDT, Tuesday, July 24th, 2012
At 12 PM: Low pressure of 1007mb was centered on the South Dakota-Nebraska state line with a stationary front south of Minnesota.
Through Wednesday Morning: The surface low will track E-NE, moving across Southern, Central, and Eastern Minnesota. The stationary front currently south-southwest of Minnesota will lift N/NE as a warm front later Tonight.
There should be a tremendous amount of moisture feeding into this system Tonight with PWATS of 1.50-2.00″ spreading into Northeast Minnesota and Northwest Wisconsin. This will lead to a potential for heavy rainfall. A low level jet increasing to 30-45 knots will help to pull some instability north into especially the Southern portions of our area later Tonight with elevated CAPE possibly reaching 1000 j/kg Overnight. This may lead to a few stronger thunderstorms with a hail and gusty wind threat, mainly from the Brainerd Lakes and I-35 corridor in Minnesota, east through Northwestern Wisconsin, but general thunderstorm activity may occur as far north as the Iron Range and North Shore areas after Midnight Tonight.
Some rain showers may get going around 7 PM (+/- an hour) This Evening around the Cass Lake, Brainerd, Aitkin, Pine City areas with the shower threat increasing in coverage and spreading farther north around Midnight. At this time, it appears that the heavier rainfall would occur in the 1 AM-8 AM time frame (Tonight/Wednesday Morning)
Overall it’s been pretty dry as of late across Northeast Minnesota and Northwest Wisconsin, so there shouldn’t be a major flood threat, but if thunderstorms begin to move over the same location for a couple hours, then there certainly could be some flood issues.
12z 7.24.12 WRF model. Rainfall totals of 0.50-1.00″ for much of Northern Minnesota and Northwest Wisconsin Tonight and Wednesday Morning with localized heavier amounts of 1.00-2.00″.
12z 7.24.12 GFS model. Not a whole lot of difference between the NAM and GFS at this time, both models show the heaviest corridor of rain setting up north of Duluth. Personally, I think both of these models are too far north with the heaviest rainfall, I still think it may favor areas south of Highway 2.
12z 7.24.12 High-Res NAM rainfall forecast, again pretty good agreement with the other 2 models. Although this model has some 3-6″ rainfall totals, note the darker red-white colors!
But, look it here, found a model that is farther south…This 1 is the Duluth WRF model (12z run) This model has the bulk of the rain generally along and south of a Grand Rapids-Two Harbors, MN line.
09z SREF model from Today. This shows where rainfall amounts could exceed 0.50″ Tonight-Wednesday AM. 50-70% chance.
And where rainfall amounts could exceed 1.00″ for Tonight and Wednesday AM. A 50% chance for parts of our area.
Tim
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