Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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908 FXUS63 KDLH 241744 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 1244 PM CDT Fri May 24 2024 .UPDATE... Issued at 957 AM CDT Fri May 24 2024 A Wind Advisory has been issued through 4 PM today for southern St Louis County, especially for those strong northeast winds into the Twin Ports around 45 mph, extending west and northwestward into northern Itasca County. The Arrowhead / Central & Northern St Louis Advisory is in effect through 8 PM for that wind hazard threat lingering into the evening longer further northeastward. While widespread gusts to 45 mph are not expected in the Advisory (closer to 30-35 mph, locally 40 mph), a strong low- level jet just off the surface may (10-20% chance) mix down very localized gusts to 55 mph today (seen at Detroit Lakes Airport surface observation within the last hour). The strongest jet winds exit the Arrowhead from 8-9 PM this evening. && .KEY MESSAGES... - Windy with rain showers today. Chances for some strong storms in northwest Wisconsin this afternoon. - Another round of showers and storms will be possible Saturday late afternoon and evening. - Active weather continues for the Northland as a low pressure system moves into southern WI for Sunday. && .DISCUSSION... Issued at 339 AM CDT Fri May 24 2024 Current conditions: A surface low pressure is currently along the border of the North and South Dakota this morning with it`s associated warm front edging its way north into our CWA. Light rain showers can be seen on radar moving north across north central MN. This rain activity is expected to dissipate over the next few hours before the next wave associated with the warm front pivots in from the south. Today: The aforementioned low pressure is expected to deepen as it continues its northeast track towards Manitoba. GEFS climatology is giving a return interval of 1 in 5 years for the pressure anomaly so I opted to increase the winds a bit with this forecast package. The strongest winds will be across northern MN closet to the Low in the afternoon hours. High res guidance is giving the area a 40-50% chance of reaching Wind Advisory criteria. There still remains some discrepancies with how much can mix down to the surface. This is due to the low maturing as a robust low level jet (winds in excess of 50kts at 2000 ft) throttles in from the southeast. Rain chances will increase through the late morning hours and persist into the evening as the warm front surges north. Some embedded thunderstorms will be possible at times. The better chances for storms will be in NW WI. The warm sector out ahead of the cold front is expected to brush NW WI this afternoon and evening and could generate some strong to severe storms. With the strong low level jet in place we will already have ample amounts of bulk shear. The main ingredient in question will be how much instability will the area generate before the cold front sweeps through. A few of the deterministic models suggest a couple hundred J/kg of MLCAPE will be possible. Meanwhile, the RAP is advertising over 1000 J/kg, certainly and outlier, but some of the CAMs do show some rather strong returns. SPC has a marginal threat (1 out of 5) outlined across a small portion of our SE counties. All modes of severe remain possible. Primary threats would be large hail up to 1 inch in diameter, 70 mph, and a possible tornado. Friday night/Saturday: The cold front will exit to the east this evening with most of the precipitation tapering off. The exception to this will be across far northern MN where wrap around moisture from the parent low now over Manitoba will lead to some persistent showery activity. The first half of Saturday looks to be quiet with increasing clouds through the day and highs in the 60s and 70s. A baroclinic zone over the region could see rain and storm chances return in the late afternoon and evening (20-40%). SPC has the area in a general risk for thunderstorms but this may need to be increased to marginal if trends hold. Some of the 00Z guidance is showing a corridor of instability within the baroclinic zone with strong bulk shear in excess of 40 kts. Sunday/Early next week: Sunday continues active weather for the Northland as a low pressure moves across southern WI. Our region will stay on the northern periphery of this system allowing NW WI to see another round of moderate rain. Current estimates are around 0.25-0.50 inches of rain with the bulk of it falling Sunday afternoon and evening. The progression of this low into next week shows some variance among ensembles but in general we can expect some additional wrap around showers to impact portions of the Northland through the early portions of the work week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1239 PM CDT Fri May 24 2024 A warm front lifting northward this afternoon bringing a line of moderate rain showers and isolated thunderstorms to far northern Minnesota over the next two hours. IFR ceilings trail in behind the warm front with drizzle and rain showers producing MVFR visibility. Over in northwest Wisconsin later this afternoon, there remain indications for a few stronger thunderstorms to fire near HYR lasting into 01Z Saturday. Kept the thunderstorm mention to only HYR for now due to confidence on the storm general locations, but DLH and BRD may have to introduce those in subsequent amendments. East-southeast winds through 00Z Saturday shift southwesterly and then westerly behind a passing cold front from 00-06Z this evening. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 339 AM CDT Fri May 24 2024 A strong low pressure moving from the Northern Plains into Manitoba today will increase the pressure gradient throttling northeast winds across Lake Superior. Gale Warnings are out for the North Shore and there is potential that they may need to be expanded to the Outer Apostle Islands depending on how the winds ramp up this morning. A few of the high res models are hinting at stronger winds by 11 AM. Gales are not expected to last for long but Small Craft Criteria will still remain until Saturday due to increased winds and waves. Additionally, rain showers will enter from the south this afternoon with the chances for some thunderstorms. Severe weather is not anticipated for Lake Superior at this time. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...Wind Advisory until 8 PM CDT this evening for MNZ011-012- 019>021. Wind Advisory until 4 PM CDT this afternoon for MNZ018-025-026- 035-037. Beach Hazards Statement until 10 PM CDT this evening for MNZ037. WI...Beach Hazards Statement until 10 PM CDT this evening for WIZ001. MARINE...Small Craft Advisory until 4 AM CDT Saturday for LSZ121-148. Gale Warning until 7 PM CDT this evening for LSZ140>145-150. Small Craft Advisory until 1 PM CDT Saturday for LSZ146-147. && $$ UPDATE...NLy DISCUSSION...Britt AVIATION...NLy MARINE...Britt