Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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510 FXUS63 KMQT 011903 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 303 PM EDT Sat Jun 1 2024 .KEY MESSAGES... - Spotty shower activity continues especially across the western half of the UP through the evening hours, ending late. Some thunder is possible. - Patchy fog, possibly dense at times, is expected to develop tonight across much of the UP. - Frequent opportunities for showers and thunderstorms over the next 7 days, with a break expected on Sunday and Tuesday. - Above normal temperatures through the first half of next week, then turning cooler. && .SHORT TERM /THROUGH TONIGHT/... Issued at 302 PM EDT Sat Jun 1 2024 A couple features of interest will keep in spotty shower activity the rest of the afternoon and into the evening. Quite apparent on water vapor imagery and RAP analysis is a deep midlevel low moving into northern Ontario. This is currently dragging a weak cold front through northern MN. To the east, a weak wave rippling from NE WI into northern lake Michigan has brought in some hit and miss, light rain showers to the south-central UP. With dry lower levels across the eastern UP, little by any way of accumulations are expected east of hwy 41. Dry midlevel air is apparent on water vapor imagery behind this wave, and more breaks in the clouds are apparent across the western UP on satellite. However, additional convection is firing ahead of a weak boundary that has been draped somewhere over western Lake Superior today. Though some higher cloud tops are apparent on visible imagery, they still remain fairly warm. Still, though we haven`t had any thunder just yet, will not totally rule this out given several hundred j/kg of SBCAPE analyzed over the western UP. Heading into the evening hours, as the cold front over MN works eastward, the spotty convection over the western UP may organize more into a broken line of showers and storms, reaching the central UP by 00Z and largely falling apart while continuing its eastward trek through the first half of the night. With quite a bit of clearing throughout northern MN behind the front, would expect skies to likewise quickly clear out from west to east across the UP tonight. Winds turn calm, and with clearing skies and plenty of ambient moisture closer to the surface, not to mention a sharp temperature inversion apparent in model soundings, we could be looking at a good night for patchy fog across the UP. This would be most likely in areas where we will have picked up some rain. Otherwise, expect a quiet night while temperatures fall back into the lower 50s and perhaps upper 40s in some of the typically cooler spots. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 259 AM EDT Sat Jun 1 2024 Expect dry conditions to return to the U.P. Sunday as the cold front leaves the far east during the early morning hours and weak sfc ridging returns to the area. With sfc ridging and zonal flow in the mid-levels over the area during the day Sunday, expect a diurnal cu field to develop over Upper MI by the afternoon hours as troughing and warm air advection begins to make its way back over the area by early Sunday evening. With PWATs around 0.75 inches, there is an outside chance (around 10%) that we could see a stray lake breeze induced rain shower or two over the central and east late in the day. However, given the high pressure ridging at the sfc, the dry air in the PBL should eat away any moisture that falls out of the cu field. Should anything make it to the sfc, expect short-lived sprinkles to light rainfall. Moving into Sunday night, expect the mostly clear skies to progressively give way to clouds as a cold front bringing showers and storms approaches from northern MN. The most recent NBM run has pushed back the timing of the showers and storms arriving over the western U.P. late Sunday night and Monday morning. In addition, the model consensus shows little, if any CAPE to work with and 0-6 km bulk shear values generally less than 30 kts. Therefore, severe weather is not expected at this time over the western U.P. Monday and Monday evening. The cold front will slowly crawl from west to east early this week across our area before weak high pressure ridging returns to the U.P. Tuesday. As this occurs, expect rain showers and thunderstorms across our area from Monday into early Tuesday morning. The low behind the cold front early this upcoming week will lift towards Hudson Bay with time before being phased with an amplifying Clipper low by the middle of next week. Strong warm air advection from the Gulf is brought over our region ahead of the cold front of the low`s arrival Tuesday and Tuesday night. Therefore, expect high temperatures Tuesday to break into the 80s across the interior areas. I could see dewpoints and RHs being lower than what`s currently being predicted by the NBM for Tuesday; if there is less cloud coverage than what`s currently predicted (partly cloudy skies at the moment), then mixing in the boundary layer will be greater, and thus dewpoints and RHs will be lower (I would wager their is around a 50% chance of this occurring at this time). As it stands now though, RHs are not expected to dip below 50%. The cold front of this low begins moving into the area late Tuesday afternoon/early Tuesday evening over the far west, with showers and thunderstorms moving over the rest of the U.P. Tuesday night through Wednesday. Once the cold front passes through, the vertically- stacked low sits over northern Ontario and brings cold air advection across our area. As this occurs, expect additional weak shortwaves rotating around the parent low to move across the Upper Great Lakes, bringing additional rain showers and possibly (15% chance) a thunderstorm or two back across the area to finish out the work week. Thus, along with the scattered rain chances, expect to see below normal high temperatures late next week; this is reflected well in yesterday`s 12z run of the EFI for the daytime Friday, with some of the ensemble runs showing highs in the 10th percentile or cooler of climatology. Therefore, we could see some unseasonably cool daytime temperatures come late next week. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 133 PM EDT Sat Jun 1 2024 Scattered light rain showers continue across the UP this afternoon and evening with a couple weak disturbances moving through this afternoon ahead of a weak cold front. VCSH continue at SAW, but a broken line of showers is beginning to work into the western UP with impacts most likely at IWD and CMX. This may drop ceilings to MVFR, and some thunder will not be ruled out at IWD over the next couple of hours. Rain showers and associated restrictions end this evening with clearing skies behind the cold front. However, as winds turn light, patchy fog is expected to develop late. This is most likely at CMX and SAW, with MVFR to IFR visiblity developing after 06Z. There is around a 20% chance for patchy fog and associated restrictions at IWD as well. Fog lifts after 12Z, then expect VFR the rest of the forecast period with light winds. && .MARINE... Issued at 259 AM EDT Sat Jun 1 2024 Light winds of 20 knots or less continue across Lake Superior until a cold front crawling eastwards across the lake brings southeasterly winds of 20 to 25 knots over the higher elevation platforms and the Lake Superior southerly nearshores Monday. Behind this, expect a return to light winds Tuesday, before stronger winds could possibly return with the coming of a second cold front Tuesday night into Wednesday; expect gusts to around 20 knots from the southwest over the western half. Moving into the latter half of next week, we could see higher winds from the northwest as cold air advection from Canada works in tandem with weak shortwaves dropping down across the area to mix stronger winds aloft to the lake`s sfc. Thunderstorms are possible across the south central and eastern portions of Lake Superior this afternoon and evening as a weak cold front moves through. Thunderstorm chances return from Sunday night to early Tuesday morning as a second cold front slowly makes its way from west to east across the lake. Additional thunder chances return late Tuesday and continue through Wednesday as yet another cold front pushes through from west to east across the lake. No severe weather is expected from these storms. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Dense Fog Advisory until 11 PM EDT /10 PM CDT/ this evening for LSZ162-263-264. Lake Michigan... None. && $$ SHORT TERM...LC LONG TERM...TAP AVIATION...LC MARINE...TAP