Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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652 FXUS63 KMQT 160531 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 131 AM EDT Sun Jun 16 2024 .KEY MESSAGES... - Dry through today before the return of showers and thunderstorms tonight with next system. - Possible strong to severe thunderstorms Sunday and Monday. - Warmer than normal with frequent chances for showers and thunderstorms through next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 121 PM EDT Sat Jun 15 2024 Clouds pressed into the forecast area this morning, accompanied by some light rain/sprinkles, thanks to a weak impulse emanating out of a more vigorous shortwave lifting northeast through Minnesota. Despite this cloud cover many locations were able to warm into the upper 60s and low 70s across the west half by 12 EDT while the east, Keweenaw, and areas near the Lake Michigan only topped out in the low 60s. Both areas should continue warming this afternoon, with mid 70s in the west and low 70s in the interior east/Lake Superior lakeshores. Lakeshore areas near Lake Michigan should remain in the 60s given the prevailing off-lake flow. Expect cloud cover to persist as well, with increasing cloud cover expected across the interior west as the aforementioned shortwave upstream presses closer to the region. && .LONG TERM /SUNDAY THROUGH SATURDAY/... Issued at 335 PM EDT Sat Jun 15 2024 Expect an active period starting this evening across our area as troughing deepens over the western U.S. and ridging amplifies over the Eastern Seaboard next week. This pattern will cycle very warm and moist air over us early next week, in addition to many chances for showers and thunderstorms throughout. With strong shearing and abundant CAPE in the atmosphere, some severe weather could occur early this week. More details follow below. Showers and a few thunderstorms begin making there way into the U.P. this evening as a shortwave low lifting from the Northern Plains into northern Ontario tonight brings isentropic ascent across our area. Given the lack of shear and CAPE across the area during the overnight hours, thunderstorms will have a hard time forming and staying together. That being said, with ensemble guidance showing PWATs exceeding 1.50 inches (which is just below the 99th percentile of modeled climatology), we could see some heavy rainfall tonight. The heavy rainfall threat continues over the area Sunday while the showers and thunderstorms look to slowly leave our area from west to east by the afternoon hours. Looking at the newest 12z guidance, the chance for severe weather Sunday seems to have gone down as the much better CAPE comes into the region behind the showers and thunderstorms due to the cloud cover breaking up behind them. However, with a 45 to 65 kt LLJ still moving across the east half Sunday, we could see a strong or severe storm or two pop up over the east if there is enough forcing with the shortwave`s passage. Behind this initial wave of showers and storms, expect mostly sunny skies and muggy conditions, with high temperatures getting into the low to mid 80s in the interior west to low to mid 70s in the interior east. With cloud cover sticking around until the afternoon hours over the west and late afternoon in the east, the high temperatures have likewise been reduced by a few degrees in this forecast package. More showers and thunderstorms could make there way into Upper Michigan come Sunday night as a secondary shortwave moves through Lake Superior. With a strong and supportive hodograph for updraft tilting, sufficient 0-6 km bulk shear, and ample MUCAPE, some elevated strong to severe thunderstorms are possible. However, there is some doubt that thunderstorms and showers will fire over our area, with some CAMs showing the convection too far to our south and west to effect our area. In addition, given that the severe weather would happen during the overnight hours, this somewhat limits the severe potential given the lack of daytime heating. Should any severe weather occur, the primary threat would be hail. The west has the best chance for seeing severe weather Sunday night. Rain and thunderstorm chances continue across Upper Michigan next week as very warm and muggy conditions also continue across the area via the troughing over the western U.S. slowly crawling eastward. Expect to see dewpoints get above 70 degrees in some spots Monday and Tuesday, with highs getting into the 80s Monday and possibly the 90s Tuesday; it`s not out of the question that we could set a heat record or two come Tuesday as ensemble guidance shows temperatures around the 99th percentile of modeled climatology. Severe weather chances continue into Monday and possibly Tuesday of next week too, as there will be plenty of CAPE and shear to work with given that we will still be under the influence of the warm, moist Gulf of Mexico airmass and with synoptic-scale frontogenesis setting up shop just to our west in the Upper Mississippi Valley and Northland/Duluth CWA. Models have us possibly being drier and warmer next Tuesday as the convection becomes more focused over Duluth`s CWA atop the synoptic-scale frontogenesis zone. As this frontal boundary crawls eastward over us Tuesday night through possibly Thursday, expect additional rain shower and thunderstorm chances, with temperatures cooling close to normal. As more zonal flow moves over us with weak high pressure setting up shop over northern Ontario and the Northern Plains, expect to see the rain and thunderstorm chances continue as shortwaves continue to ride the upper-level flow across our area. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 130 AM EDT Sun Jun 16 2024 Conditions will deteriorate overnight into Sunday morning as a system spreads rain into the region. Expect all sites to fall to MVFR by morning, possibly IFR at KSAW by late morning/early afternoon. Wind shear will also be likely at all terminals overnight into Sun morning and could last through the period at SAW. Gusty winds will develop by morning at all sites. && .MARINE... Issued at 335 PM EDT Sat Jun 15 2024 Some southeast becoming southerly winds of 20 to 25 knots over the central lake this afternoon and evening eventually dies down to 20 knots or less before ramping up to 30 knots from the southeast to south Sunday morning to afternoon over the central lake once again. In addition, some southerly gusts up to 30 knots will be possible along the south Lake Superior nearshores throughout the day, with a few gale force gusts up to 35 knots being possible near Grand Marais and Munising during the afternoon hours. Winds weaken to 20 knots or less by late Sunday afternoon/evening and remain that way until possibly next Tuesday, when some southerly winds of 20 to 25 knots could be seen along the south nearshores. Light winds of 20 knots or less returns Tuesday night and could remain through the rest of the week. Thunderstorms are possible across the lake beginning late tonight, with chances continuing through the middle of next week. Some severe weather is possible over the lake, particularly the west, from Sunday through Tuesday as a zone of frontogenesis sets up near Duluth; the primary severe threat is hail, followed by winds. In addition, while significant wave heights look to be generally 4 feet or less over the next several days, we could see wave heights get up to 4 to 6 feet over the eastern half Sunday given the stronger southeast to southerly winds. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JTP LONG TERM...TAP AVIATION...Voss MARINE...TAP