Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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449 FXUS63 KDLH 172054 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 354 PM CDT Fri May 17 2024 .KEY MESSAGES... Key Messages: - Scattered showers and some storms through the rest of today - Marginal Risk for severe storms on Saturday with large hail up to quarter size and gusty winds being the biggest concern - Quick dry spell before our active weather pattern returns next week with multiple shots for rain && .DISCUSSION... Issued at 326 PM CDT Fri May 17 2024 Short Term: As of early afternoon, some weak reflectivity returns can be seen on radar across the Minnesota Arrowhead. This is tied to a weak vorticity maxima swinging through the region which is causing some weak ascent ahead of it. This has led to showers and drizzle in areas close to the Canadian Border. This should continue to push northward and out of the area in the next few hours. Following this, clear skies should be present with highs topping off in the mid to upper 70s across much of the region. Areas closer to the lake will stick in the 50s and 60s due to the presence of a lake breeze slowly moving inland. Through this afternoon and evening, there is a low end chance (30-40%) of some showers and storms refiring across our CWA. Some of these showers could be a bit stronger than the ones we saw this morning with some lightning possible and stronger gusts at times. Some scattered showers will persist overnight as we get strong isentropic advection from the south. Mid-Range: Our eyes turn to tomorrow and the threat of storms across our CWA as a cold front sweeps through the area. As it stands right now, the SPC has put the eastern half of our CWA in a Marginal Risk (Level 1/5) for severe weather tomorrow. The main threats would be large hail up to quarter size and gusty winds up to 60mph within the stronger convection. A trough swinging through the Canadian Prairies tonight will reach our area late Saturday Afternoon. Itll induce cyclogenesis of a surface cyclone thatll advect moisture into the area pushing dewpoints into the upper 50s and even lower 60s by mid afternoon. The result of these two things is anywhere from 500-1500 joules of MUCAPE to form by afternoon with 40-50kts of Bulk Shear in our vicinity. This will lead to organized convection forming in the early afternoon near the I-35 Corridor before overspreading further east through the rest of the evening. Following the cold front, Sunday should be mostly dry with high topping off in the low to mid 70s with a light westerly wind to top it off. Extended Range: The quick dry spell will quickly end as we begin the workweek with a quick moving shortwave moving through the Northern Plains on Monday. While nothing too substantial is expected out of it, we could see some scattered showers and thunderstorms across the CWA during the daytime on Monday. As that moves out of the region Monday afternoon, a more notable and impactful system will ride into the Northern Great Lakes by Tuesday morning. While we wont see many convective storms being north of the surface low, we will mainly see a prolonged period of rain. The rain which could be heavy at times will lead to QPF totals in excess of 0.5-1.5 in a 24 hour time frame. We should see quieter conditions arrive following this storm to close out the work week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 100 PM CDT Fri May 17 2024 It`s looking like we should see a nice break from any showers/storms for the rest of the afternoon and early evening, aside from a shower or two passing through HYR within the next hour. While the air following behind this initial area of clouds and showers is warm, it is also dry, and thus there isn`t much to support additional showers/storms this afternoon. There may be a 10-15% chance that a stray shower/storm could develop, but not enough confidence to put in any TAFs. Later this evening, warm air advection continues out ahead of an approaching cold front from the west. We will likely see some scattered showers/storms developing and passing by overnight. In addition, periods of fog may be possible away from any showers/storms, so expect occasional MVFR to potentially briefly IFR ceilings and visibility tonight. LLWS is also expected overnight with a potent low-level jet developing. The shower/storm chances will continue through about mid-day at Minnesota terminals, ending after the cold front passes through. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 326 PM CDT Fri May 17 2024 Issued a 6-hour Small Craft Advisory from Duluth to Sand Island as winds have gusted to around 25 kt at Port Wing the past couple observations. Winds are expected to lessen gradually this evening, but some higher waves up to 4 ft could linger. Otherwise, northeast winds lessen tonight, then gradually shift to southwest on Saturday as a cold front passes through. Some stronger wind gusts approaching 20-25 kt may be possible around the head of the lake Saturday afternoon. A Small Craft Advisory may be needed. Scattered showers and thunderstorms are possible overnight (30% chance), then some strong to low- end severe storms are possible through Saturday afternoon (50-70% chance of storms and 5-10% chance for strong to severe storms capable of producing strong winds to 50 kt and large hail up to quarter size). 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...None. && $$ DISCUSSION...KP/JDS AVIATION...JDS MARINE...JDS