Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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674 FXUS63 KDLH 021734 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 1234 PM CDT Tue Jul 2 2024 .KEY MESSAGES... - Areas of heavy rain has occurred over portions of far northern Minnesota, mainly across parts of Koochiching, northern St. Louis, and far northwest Lake Counties. The Flood Watch continues there as runoff works its way into rivers and streams. - Showers and a few thunderstorms this morning will end from southwest to northeast with additional isolated to scattered showers/storms this afternoon and early evening. - More rain expected later Thursday into Friday and it could be heavy, especially over southern portions of the Northland. && .DISCUSSION... Issued at 342 AM CDT Tue Jul 2 2024 A southerly 45 to 50 knot jet continued this morning and was aiding in producing showers and a few thunderstorms. Instability was meager at best and only a few thunderstorms are expected this morning. Heavy rainfall has occurred over portions of Koochiching, northern St. Louis, and far northwest Lake Counties. Observations show amounts from 1 to 2.5" as of 3AM. Showers continued across much of the Northland but were ending over southwest portions. Additional rainfall this morning will be up to a half inch. We cancelled the Flood Watch for all but Koochiching, Northern St. Louis, and inland Lake/Cook Counties. Runoff from the heavy rain will be working through rivers and streams today. The low level jet will shift east and veer to southwest through this morning. Prior to that, isolated higher gusts of 30 to 40 mph will be possible, mostly likely over northwest Wisconsin. A frontal boundary extended south out of low pressure in southern Manitoba through the Red River Valley into Nebraska this moving. After the showers move off or diminish in coverage this morning, additional development will occur this afternoon, especially ahead of the frontal boundary. CAPE will increase to 400 to ~1000j/kg so a few thunderstorms will occur as well. Coverage of the showers/storms are not expected to be widespread so additional widespread heavy rain is not expected. Showers/storms will end tonight and it should be dry into Wednesday morning for most. There is a chance for a few showers/storms to develop Wednesday afternoon over much of the Northland and we have 20-30% POPS going over all but far southern portions. Highs Wednesday will be from the lower seventies to around eighty. A stronger shortwave will arrive on Thursday with a surface low forming. There is general consensus among the deterministic models that the upper wave and surface low will move through southern Minnesota or northern Iowa and Wisconsin Thursday into Friday. ECMWF ensemble members show a significant spread in low track. There is potential for heavy rain over portions of the Northland, with southern areas favored at this time. There is some instability to work with too although PWAT values are a bit lower, around 1.4", compared to the current system. The NBM has 30-50% chance for rainfall of 1" or greater Thursday into Friday night from east central Minnesota into northern Wisconsin. An upper ridge will build over the western CONUS/western Canada over the weekend with north/northwest upper flow over the Northland. A couple more shortwaves will dive southeast and bring rain chances but these system will be more progressive. Temperatures will be seasonal through much of the period with cooler temperatures occurring Friday over southern areas which will see the highest chances for rain. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1226 PM CDT Tue Jul 2 2024 An area of LIFR to IFR sky cover exits north-central Minnesota over the next hour or two, while lasting into northeast Minnesota and northwest Wisconsin through 00Z today. Showers increase again from west-central Minnesota into the Brainerd Lakes around 21Z and into northeast Minnesota through 05Z. Isolated thunderstorms are most likely near HIB and INL this evening. Overnight mist may setup to create MVFR to IFR visibility at some terminals. West-northwest winds create gusty conditions daytime Wednesday. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 342 AM CDT Tue Jul 2 2024 Southerly winds are expected today, from 10 to 15 knots with gusts to 20 knots for most areas. However, stronger winds aloft may mix down at times creating stronger winds with gusts to 30 knots. This is most likely from the Twin Ports and South Shore and we issued a Small Craft Advisory there into this afternoon. A few thunderstorms will be possible today, mainly this afternoon and evening. The wind will veer to southwest tonight and be at 15 knots or less. West or southwest winds will strengthen Wednesday to 10 to 20 knots with higher gusts and Small Craft Advisories will likely be needed over portions of the nearshore waters. 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...Melde AVIATION...NLy MARINE...Melde