Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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417 FXUS63 KMQT 290545 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 145 AM EDT Wed May 29 2024 .KEY MESSAGES... - Dry air mass will support borderline elevated fire weather conditions across parts of the interior west today. - Below normal temperatures through Wednesday night, then warming up through early next week. - Areas of frost expected Thursday morning. && .SHORT TERM /THROUGH TONIGHT/... Issued at 145 AM EDT Wed May 29 2024 Surface trough moving south into Upper Michigan has supported a couple isolated patches of light rain here and there in the past few hours. This should end in the next hour or so as the trough continues to drop south. Temps so far have been in the 40s and 50s. Otherwise, surface high building south and east out of Ontario will increasingly influence our weather through this period. The increasing dry air and clearing skies may support efficient radiational cooling in parts of the interior west this morning and I wouldn`t be surprised if some spots drop into the upper 30s by sunrise. Today, the dry air will dominate as high pressure continues building into the region. The cooler airmass should keep highs in the 50s by Lake Superior and low-mid 60s elsewhere. Dinural heating should promote healthy mixing and enable drier air aloft to mix down to the surface. RH values are largely expected to fall to 25-30% away from the lakeshores but isolated pockets of the interior west could see RH in the 20-25% range. With this same area potentially climbing to near 65F today, borderline elevated fire weather conditions will be met. Winds are expected to be northerly at 10 mph or less in these areas though, which should mitigate fire weather concerns. Across the east, winds may build to 15-20 mph in some locations, but temps are expected to remain in the low 60s. && .LONG TERM /WEDNESDAY THROUGH TUESDAY/... Issued at 431 PM EDT Tue May 28 2024 The extended forecast starts off with a quiet and dry period through Thursday night thanks to sfc high pressure and mid level ridging moving through the region. This is followed by precip chances for the weekend into early next week as we track out shortwaves into the Upper Great Lakes. Temperatures are expected to be cooler than normal through Wednesday night, warming through the early part of next week as ridging shifts toward the Atlantic coast and WAA increases. Starting on Wednesday, mid level ridging will be centered over the Northern Plains with a trough over the Pacific Northwest and a closed low over northern Quebec. A shortwave departing southeast from the area early in the morning with sfc high pressure building in over the Upper Great Lakes will result in sunny skies for the entire UP by mid morning. This sfc high pressure extending from James Bay will also yield dry north flow to the UP with PWATs dropping to around 0.25" to 0.3" by the end of the day. The 5/28 0Z NAEFS indicates PWATs of these values are below the 10th climatological percentile for our region. With model soundings indicating mixing up to 800 mb in the interior and around 900 mb by the lakeshores and in the east, min RHs Wednesday afternoon are expected around 25-30%. This means the UP flirts with borderline elevated wildfire conditions as the west is warmer with highs in the mid 60s, but gusts stay mainly below 15 mph. Slightly cooler temps are expected over the east in the 50s near Lake Superior to low 60s in the interior with gusts approaching 15-20 mph. That being said, the wet pattern we have observed over the last few days leaves little fire weather concerns at this time. PWATs continue to drop for Wednesday night (nearing the minimum of the NAEFS climatology of 0.15" to 0.25") with sfc high pressure continuing to build over the Upper Great Lakes. Good radiational cooling will bring lows below normal into the 30s, coldest in the interior. With near calm conditions, a dry airmass, and colder temps, areas of frost are likely away from the Great Lakes lakeshores late Wednesday night into Thursday morning. Thursday sees more mixing and dry conditions similar to Wednesday as mid level ridging builds in. While mixing is not expected to be as high, temps are expected to be warmer in the upper 60s to mid 70s in the interior with cooler temps by the lakeshores. This brings min RHs in the interior into the 20% range, higher near the lakeshores (30-50%). Winds are expected to be lighter (gusts mainly below 15 mph save for the Keweenaw), so wildfire conditions stay low. Thursday night brings lows mainly in the 40s under mostly clear skies. PoPs return to the forecast on Friday as a weak cold front moves into the west. With minimal instability (highest CAPE below 100 J/kg) and a weakening frontal boundary, mention of thunder was removed from the forecast through Friday night. Chances for showers and thunderstorms increase on Saturday as a shortwave moves from the Northern Plains Friday night over just north of Lake Superior late in the day Saturday with ridging shifting toward the Atlantic coast. An additional shortwave lifts northeast from the Southern Plains Friday into the lower part of the Great Lakes Basin for late in the weekend. Another shortwave tracks east from the northern Rockies Sunday night through the Great Lakes region Monday/Tuesday ahead of a deeper trough for late next week. The rapid shortwaves progressing through the region this weekend into next week yields a wetter pattern for the weekend into early next week. That said, accumulations are not expected to be high as NBM probabilities of at least 0.1" of QPF in a 24 hour period for the most part stay below 50%. With spread in the guidance among timing and track of the shortwaves, opted to leave NBM PoPs as is. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 126 AM EDT Wed May 29 2024 Expect VFR conditions to prevail in this forecast period at all TAF sites under surface high pressure. VFR cigs should clear out by late morning with mostly clear skies thereaafter. Expect mostly lake breeze winds of 10 knots or less during the day on Wednesday. && .MARINE... Issued at 431 PM EDT Tue May 28 2024 High pressure builds southeast into the Great Lakes through tonight, slowly continuing southeast over the Great Lakes Basin into this weekend. This leaves light northerly winds through tonight, mainly below 20 knots; variable winds around 5 to 15 knots are expected for Wednesday and Wednesday night. With probabilities of winds exceeding 22 knots below 20% through this weekend, winds are expected to mainly remain below 20 knots into the early part of next week with no major systems in the vicinity of Lake Superior. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JTP LONG TERM...Jablonski AVIATION...JTP MARINE...Jablonski