Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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994 FXUS63 KMQT 171722 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 122 PM EDT Tue Sep 17 2024 .KEY MESSAGES... - Extended stretch of well above normal temperatures continues through at least Thursday with highs mainly in the upper 70s and 80s. - Next credible chances of precipitation arrive Thursday night and continues through Friday night. More rain is possible early next week. && .SHORT TERM /THROUGH TODAY/... Issued at 121 PM EDT Tue Sep 17 2024 Dry and warm airmass continued to sit over the Upper Great Lakes today. Outside of some mid-high clouds here and there, and some recently developing diurnal cumulus in the west, the forecast area has been mostly clear which enabled many to easily break into the 70s before noon. In fact, many locations were beating hard on the 80 degree door at that point. As of publishing this discussion, most surface observations were in the upper 70s to low 80s, which is approximately 10 to 15 degrees above normal for mid-September. Under mostly light southerly flow, daytime mixing has supported dewpoints in the mid 50s to low 60s. This is yielding RH values mostly in 50s and 40s in areas removed from Lake Michigan`s influence. Some drier locations have fallen into the 30s as well. As we progress through the remainder of the afternoon, I expect temps to climb a little more and RH values in the 40s to be more widespread with some 30s here and there before recovering with the waning heat. Expecting clear skies to continue through tonight, which will yield overnight lows in the 50s and 60s, save the interior portions of south-central and east, which could slip into the 40s. Patchy overnight fog will be possible as well, particularly in the interior spots of central and eastern Upper Michigan. && .LONG TERM /TONIGHT THROUGH MONDAY/... Issued at 328 AM EDT Tue Sep 17 2024 Expect the dry and very warm weather to remain over the area early in the extended period before a cold front moves in Thursday night through Friday night and brings some much needed rainfall to the Upper Peninsula. After a quick dry spell early this weekend, expect additional rain chances early next week as a low pressure lifts from the Southern Rockies into the Upper Midwest. High pressure ridging persists over the U.P. tonight into Thursday as a vertically-stacked low continues to lift from the Intermountain West into the Canadian Prairies. The ridging will allow sunny skies and the very warm temperatures to continue through the middle of this week; we could still flirt with tying or breaking the max temperature record in several spots on Wednesday and Thursday, even though we aren`t expected to be as warm as we have been the past couple of days. In addition, with the lack of rainfall over the area, especially over the central and east over the last several days, some fire weather partners may be concerned about some of the fuels continuing to dry-out. Nevertheless, with the high pressure ridging persisting overhead, winds are expected to remain fairly light from the south, and min RHs are expected to remain above 30%. While some shortwave action over northern Ontario may bring some showers and storms to Isle Royale and maybe (10% chance or less) to the Keweenaw Wednesday, outside of that the next couple of days will be perfect if you need to get any outside work done; just be sure to take your water breaks given the sun and heat. Some rainfall looks to return to the forecast Thursday night as a cold front looks to meander it`s way into the western U.P. late overnight. The front continues through the rest of the U.P. Friday and Friday night, bringing showers and some storms across the area. While a sharp drop in temperature isn`t expected with this front, with the additional cloud cover overhead, expect high temperatures to drop a little closer to normal (i.e. the 70s). That being said, we could see some record high min temperature records broken Thursday night and possibly even Friday night over the east given the antecedent warm air ahead of the front and the associated cloud cover. In addition, the rainfall along the slow moving front may bring some much-needed relief to our area, particularly because we haven`t had much rainfall over the past week and we are already experiencing abnormally dry conditions (D0) according to the drought monitor. As for severe weather, none is currently expected given the relatively modest lapse rates and wind shear. While model guidance begins to noticeably spread this weekend and continues increasingly so early next week, we should see a short dry period at least early this weekend as some ridging scoots through the Upper Great Lakes. Nevertheless, the differing model suites do bring a stacked low pressure from the Southern Rockies up into the Upper Midwest by early next week. This low looks to bring some much- needed additional rainfall across the U.P. via a front or two. However, the rain chances and timing are still dependent on the low`s placement and timing. In addition, temperatures look to continue decreasing early next week, with highs now projected to only get into the 60s. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 121 PM EDT Tue Sep 17 2024 Dry airmass over the region will continue VFR conditions at KIWD/KCMX/KSAW in this TAF period. Winds will be mostly southerly save for the afternoon lake breeze at KCMX. There may be 15 to 20 kt gusts at KIWD and KSAW this afternoon. && .MARINE... Issued at 328 AM EDT Tue Sep 17 2024 Light winds of generally 20 knots or less continue for the next several days has high pressure ridging this week finally gives way to a cold front moving through Thursday through Friday night. This front could bring some showers and storms over Lake Superior, as well as some stronger winds above 20 knots as it slowly crawls from west to east. Moving into this weekend, there is some model spread on when a low pressure lifting from the Southern Rockies will arrive over the Upper Midwest (as well as it`s placement). However, we may see winds increase above 20 knots again come late this weekend/early next week as the low approaches. Otherwise, the only other thing we might see is some showers and storms over the northern and western lake tonight into Wednesday as a shortwave lifts across northern Ontario. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JTP LONG TERM...TAP AVIATION...JTP MARINE...TAP