Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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820 FXUS63 KMQT 131143 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 743 AM EDT Thu Jun 13 2024 .KEY MESSAGES... - Gusty northwest winds are expected today along with additional chances for isolated showers and thunderstorms. There is a marginal risk (category 1/5) of severe weather for most of the UP, with the main threats being large hail in excess of an inch and damaging winds in excess of 60 mph. - Dry Friday and early Saturday before the return of showers and thunderstorms later in the weekend. - Warmer than normal temperatures frequent the forecast, with some areas approaching 90 for highs by next week. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 514 AM EDT Thu Jun 13 2024 RAP analysis shows a mid level trough over southern Manitoba with a weak low pressure trough at 1004 mb extending over Lake Superior and into the UP. A cold front drapes from western lake superior northeast into northern Ontario. Showers and lingering thunderstorms have almost made their way out of the UP, but dry weather is expected within the next hour as PVA diminishes and this sfc low pressure trough slowly moves east this morning. This dry period is only expected to be brief as mid level trough rotates east through northern Ontario, sending a stream of vorticity south across the UP today. As the sfc low pressure trough progresses east toward Quebec, it deepens and brings the cold front eastward across the UP through early this afternoon. CAMs do not have the greatest agreement on the timing of shower and storm activity today, but there does seem to be a consensus on two periods. The first one being a round progressing east across the UP with the cold front. The second period would be more PVA forced in the later part of the afternoon. The marginal risk for much of the UP seems appropriate for today as neither of these rounds is a home run. Bulk shear of ~50 kts will be sufficient for storms throughout the day, but the best instability (6/13 0z HREF mean SBCAPE to around 1000 J/kg) is expected in the earlier part of the afternoon ahead of mid level lapse rates increasing to near 7C/km. That said, some isolated stronger to severe storms are possible. If any severe storms are able to develop (5% chance), the main threats will be hail and winds. CAA and drier air behind the cold front will allow for some good mixing resulting in some gusty northwest winds. While the 6/13 0z HREF indicates only a 40-60% chance of wind gusts exceeding 30 mph, model soundings do indicate the potential for isolated gusts as high as 40 to even 50 mph. These gusts are not expected to be consistently high enough for an advisory, but it will still be a gusty day. Highs for the most part are expected in the 70s with the south central UP being warmer in the low to mid 80s. The other exception to highs in the 70s would be those near Lake Superior which may only see highs in the 60s. && .LONG TERM /TONIGHT THROUGH WEDNESDAY/... Issued at 547 AM EDT Thu Jun 13 2024 After a few lingering showers/thunderstorms (far south) this evening, high pressure will strengthen over Upper Michigan. This will bring a lull to the active weather and dry conditions for a bit. Meanwhile though, focus will be on a potent cutoff low over the Pacific Northwest and the potential for several rounds of showers and thunderstorms through the weekend/next week ahead and with it. With multiple lifting mechanisms in the pattern, there will still be much ambiguity in regard to timing and strength of storms. The first round, though, is expected to arrive late Saturday as a wave approaches just ahead of a surface low centered over central Manitoba. This disturbance will help to transport moisture from the Gulf and strong WAA ahead of the aforementioned cutoff and surface lows. And, early indications are trending toward a cold front moving through this environment on Sunday. Again, it is still tough to pinpoint the details of the dynamics, but one thing for certain is that there will be a strong warming trend through next week. And, this hints at some unstable environments in place until the timing of the dynamics come into better agreement. Temperatures will already start out above normal on Friday with highs climbing into the low to mid 70s. And, the trend will continue through the weekend with mid to upper 70s and finally mid to upper 80s across portions of the interior by Monday and through the week. So, overall a warm and wetter pattern throughout the extended period. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 743 AM EDT Thu Jun 13 2024 Mainly VFR conditions are expected at all TAF sites for the duration of the 12Z TAF period. The exception to this would be for a period of MVFR to possibly IFR cigs at CMX this morning with northwest upslope flow off Lake Superior. Daytime mixing will support gusty west becoming northwest winds with the current forecast for 25-30kt, but some guidance suggests mixing could support infrequent gusts upwards of 40kts in the afternoon. Some isolated showers and thunderstorms are possible this afternoon mainly at CMX and SAW. With low confidence in timing and coverage, opted to only include VCSH at SAW and CMX for now. Winds taper off this evening as showers diminish. && .MARINE... Issued at 324 AM EDT Thu Jun 13 2024 Southwesterly winds will become west-northwesterly and increase behind a cold front later this morning with gusts of 20 to 25 knots. By Friday, winds will return to less than 20 knots with the return of high pressure where they will stay until early Sunday morning. At that point, the next cold front will bring southerly winds of 20 to 25 knots along with 4 to 5 foot waves along the US/Canada border on Lake Superior. In addition, thunderstorm chances will return to the forecast, but it is too early to determine severity. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Jablonski LONG TERM...TDUD AVIATION...Jablonski MARINE...TDUD