Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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144 FXUS63 KDLH 072111 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 411 PM CDT Tue May 7 2024 .KEY MESSAGES... - Thunderstorms will occur this afternoon with isolated strong thunderstorms mainly south of US Highway 2. The stronger storms could produce nickel-sized hail and wind gusts to 50 mph. - Fog is expected to form tonight. - Frost is possible (60% chance) in the Arrowhead Wednesday night. A freeze is likely in NW WI Thursday night. - Two weak clippers cross over the area bringing light rain Friday and Sunday. && .DISCUSSION... Issued at 410 PM CDT Tue May 7 2024 A fairly large and dynamic low pressure to our west is rotating bands of rain and thunderstorms north into our forecast area this afternoon. Clearing behind a warm front this morning and the subsequent heat loss from precipitation and lack of insolation due to cloud cover has set up a baroclinic zone with a secondary warm front lifting north this afternoon. A sliver of MUCAPE sneaks northward into the southern portion of our forecast area peaking out around 1500 J/kg per the latest RAP analysis in concert with 20 kts of 0-6 km shear. This gives a bit of a stronger thunderstorm threat albeit isolated to our southern border which is pretty close to where the SPC marginal risk is for this afternoon though I may have extended that line a bit more west into Aitkin County. Most storms should be run of the mill, but there may be some overachievers. Luckily the window for good convection isn`t too large and the stronger storm threat decreases greatly after 00Z. The rain that does or has fallen will saturate the BL overnight causing fog to form though it may be just a low stratus deck as the waves of precipitation that rotated north over us today sag back south again overnight bringing low clouds and possibly drizzle in concert with the fog. High pressure builds Wednesday with skies clearing overnight causing temperatures to plunge and this will give the potential for frost in the MN Arrowhead on Wednesday night. An even deeper plunge into sub-freezing temperatures across NW WI occurs Thursday night and will likely need some frost/freeze headlines. Afterwards, it`s active, but not too bad with clipper systems expected Friday and Sunday. Each of these are warm enough for just plain rain, but also not a lot of rain <0.5" per system and probably less than 0.25" for most places. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1231 PM CDT Tue May 7 2024 A smattering of just about every flight category out there. While a wave lifts north, the same wave is expected to return tonight leaving a band of IFR or lower conditions over the forecast area. Thunderstorms are possible (60 percent chance) with afternoon convection, but will only extend as far north as 30 nm north of Duluth with the highest chances between 21Z and 03Z. Winds will be gusty to start with but will decrease tonight leading to potential fog formation. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 410 PM CDT Tue May 7 2024 Still expecting some occasional gales along the North Shore this afternoon so keeping the gale up there, but did trim off the southern portion of it. Small crafts follow with a little break early Wednesday before winds and waves build again. We may flirt with gales near the Twin Ports again Wednesday afternoon in strong northeasterly flow. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...Gale Warning until 6 PM CDT this evening for LSZ140>142. Small Craft Advisory until 4 AM CDT Wednesday for LSZ143>146. && $$ DISCUSSION...Wolfe AVIATION...Wolfe MARINE...Wolfe