Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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284 FXUS63 KMQT 271733 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 133 PM EDT Mon May 27 2024 .KEY MESSAGES... - Below normal temperatures for the first half of the week, followed by a drying trend midweek. Areas of frost expected Thursday morning. && .UPDATE... Issued at 1021 AM EDT Mon May 27 2024 The forecast remains largely on track this morning. With deep low pressure centered over the central LP expected to slide ENE over Lake Huron today, widespread rain showers continue to pivot across the eastern UP. So far, these are staying mainly east of the eastern Marquette and Menominee county borders. Still, per simulated reflectivity the rest of the day, will not rule out a stray shower moving through the central UP, a bit more to the west. PoPs and QPF have been updated to reflect current radar trends. Under cloudy skies, cool onshore flow, and rain, temperatures closer to Superior in the eastern half of the UP may struggle even to reach the mid 50s, so temperatures have been undercut slightly as well. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 234 AM EDT Mon May 27 2024 Upper air pattern consists of a 500 mb closed low in eastern Manitoba with a shortwave over the upper Great Lakes with another shortwave over the northern plains. The northern plains shortwave heads east and helps the trough amplify over the Great Lakes region 00z Tue. 850-500 mb q-vector convergence and deeper moisture remain over the eastern half of the cwa today while the west is drier. This will continue to be where the highest pops will be while the west remains mostly dry. Overall, did not make too many changes to the going forecast. && .LONG TERM /TONIGHT THROUGH SUNDAY/... Issued at 316 AM EDT Mon May 27 2024 Recent deterministic and ensemble guidance packages are continuing to handle the up coming pattern consistently for Upper Michigan. The long term pattern for Upper Michigan will start off with broad mid- level troughing overhead as today`s surface low pulls away through Ontario into Quebec. Within this flow, a shortwave will press east through MN/WI into this evening followed by a weakening closed low pressing through the Upper Great Lakes Tuesday. Afterwards, ridging builds into the region for the latter half of the week followed by a cold front for the weekend. In terms of sensible weather, weak ridging will sit atop the shortwave moving south of the region today, supporting a dry evening across the west. After midnight though, the leading edge of the next shortwave moves in, potentially supporting showers in the west by early Tuesday morning. Rain showers in the east should continue their slow diminishing trend as the surface low to the northeast pulls away to night into Tuesday. A cooler airmass will build into the region tonight and Tuesday alongside the closed mid-level low. While the better synoptic forcing appears to be south and west, increasing instability through the day coupled with the possible morning shortwave, could support increasing coverage of showers through the day in the west, possibly a thunderstorm as well. Ridging and an increasingly dry airmass will build into the region late Tuesday night and then persist through at least Friday. This, alongside the cooler airmass will continue Tuesday`s daytime highs of 50s and 60s into Wednesday. Frost may be a concern for portions of the interior west Tuesday night and will be for most interior locations Wednesday night. Confidence is high (>75%) for patchy to areas of frost Wednesday night. While our internal model certainty tool and NBM probabilities suggest a 50% chance of falling below 35F for interior portions of Upper Michigan, both EC and GEFS ensemble suggest PWATS of 20-30% of normal. Given this, subsidence overhead, and the weak winds, I suspect a freeze may even be on the table. At this point, a Frost Advisory seems likely (>75% chance) Wednesday night but will continue to monitor model trends. While frost is also possible Tuesday night, the timing of the drier air and potential for continued winds above 5 mph suggest radiating out may be more difficult. Guidance also continues to suggest the dry and well-mixed boundary layer will support plummeting dewpoints and RH falling below 30% away from the lakeshores Wednesday and Thursday. A mitigating factor for the fire weather risk, in addition to fairly light winds, will be the widespread rain in the preceding days. Ridge axis builds into the region Thursday night while another trough presses out of the Rockies. Guidance consensus continues to suggest the surface high and dry conditions will win out through at least Friday night, with increasing rain chances Saturday with the passage of a cold front. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 133 PM EDT Mon May 27 2024 Low pressure continues to move eastward through the Lower Peninsula, which is maintaining widespread rain showers and low cloud cover over the eastern UP. SAW remains on the NW edge of the rain shield, under NNE upslope flow that is keeping in IFR ceilings at least for the next couple of hours. These low clouds are likely to persist until this evening when VFR should return as winds turn more to the NW and drier air begins to work in. At IWD and CMX, meanwhile, VFR prevails for the rest of the forecast period. There is a chance for some -shra into Tuesday morning, particularly at IWD, with another weak disturbance moving through. Coverage and timing of showers is uncertain, so only vcsh has been included in the TAF. Restrictions are unlikely with only around a 20% chance for ceilings to drop to MVFR at IWD. Otherwise, expect NNE winds to turn more NNW through hte forecast period at all terminals. && .MARINE... Issued at 316 AM EDT Mon May 27 2024 A surface low will track northeast across Lake Michigan and northern Lower Michigan today. As the low transits, expect primarily northeast winds to become northerly this morning, and then northwesterly by evening. Winds are mostly expected to be 20 to 30 knots across the east half while the west remains below 20 knots. Wave heights of 4 to 7 feet should be expected across the east half. The low will pull away tonight with these elevated northwest winds continuing into Tuesday night across the east. High pressure builds across the lake on Wednesday supporting light and variable winds and decreasing waves until Thursday midday, when light easterly to southeasterly flow at 5-15 kt re-establishes itself across the western lake, along with waves 1-3 ft. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ005-006. Lake Superior... None. Lake Michigan... None. && $$ UPDATE... SHORT TERM...07 LONG TERM...JTP AVIATION...LC MARINE...JTP