Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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492 FXUS63 KMQT 250858 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 458 AM EDT Wed Sep 25 2024 .KEY MESSAGES... - Patchy fog ends within an hour or two after sunrise. Some areas of fog may be dense at times, reducing visibilities to 1/2 mile or less. - Dry weather is expected this week into the weekend. - Temperatures trend well above normal into next week. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 414 AM EDT Wed Sep 25 2024 Current RAP analysis shows the 1006mb low centered over Lower MI underneath a shortwave. This is currently lighting up the radar returns over northern Lower MI and the far eastern UP as light showers lift through Luce County. The stronger mid level features include mid level trough over northwestern Ontario, an additional trough over the Mid Mississippi Valley, and a strong ridge over the Rockies. The showers over the east will continue to lift north through Sunrise as the low moves toward Lake Huron. These showers alongside the low cloud deck are keeping temps warmer in the east in the mid to upper 50s. In contrast, a drier airmass to the west has limited mid level clouds ahead of the trough to the northwest. Thus, radiative cooling under these clear skies has allowed for temps to fall into the low 40s. With the strong inversion in place and light winds, this set up has resulted in patchy fog development across the west half. Some of this fog has been dense at times, particularly along the WI/MI state line where visibilities have periodically dropped down to 1/2 miles or less. While a few spots may dip into the mid to upper 30s ahead of sunrise, fog may limit cooling. Patchy fog is likely to prevail through a hour or two of sunrise. As the low pressure lifts north over Lake Huron to northern Ontario this morning and low level winds turn northwest, showers diminish and are forced east out of the CWA. Some scattered low level clouds may accompany the eastward progressing trough to the north, but mostly sunny skies and dry weather is expected today as the mid level ridge progresses east toward the Great Lakes. Temps warm above normal today, peaking in the mid 60s to mid 70. Also, mixing this afternoon may result in some west winds gusting up to 20 mph in the Keweenaw. && .LONG TERM /TONIGHT THROUGH TUESDAY/... Issued at 432 AM EDT Wed Sep 25 2024 Synoptic setup across the CONUS early in the extended period consists of strong ridging shifting from the Rockies into the Plains and mid-level troughing extending into the Great Lakes Region. Farther south, a closed low is centered over the western Tennessee Valley, while Tropical Storm Helene spins in the Gulf of Mexico. Elsewhere, broad troughing is influencing the west coast. So, essentially, this omega block pattern will keep the forecast dry across Upper Michigan for the majority of the long term period. Therefore, the main focus through the weekend and into next week will be the above normal temperatures and the fluctuation between summer and fall that comes around this time of year. Daily high temperatures will generally be in the 70s and even near the 80 degree mark from Thursday through Saturday in the southerly surface flow. Meanwhile, overnight lows will elude any freezing marks with widespread 40s/low 50s through Monday night. By Tuesday, however, long range ensemble models trend toward the shift back to Fall and normal high temperatures in the 60s and overnight lows dipping back into the upper 30s. Outside of the dry weather and above normal temperatures, there will be a few drawbacks. First, with the mostly clear skies and light winds, radiational fog will pretty much be a nightly possibility throughout the extended period. Then further out, the pattern will finally shift as the ridge axis shifts and is replaced by the next low pressure system over northern Manitoba on Monday. This will likely be the UP`s next chance at rain showers, but ensembles do seem to be overdoing the precipitation chances a bit with probabilities up to 50%. Due to it still being days 5 and 6 though, will not deviate from Pops at this time until confidence increases with evolution of the associated cold front. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 141 AM EDT Wed Sep 25 2024 VFR is expected to prevail thru this fcst period at CMX. At SAW, radiational fog should develop under mostly clear skies and little to no wind. IWD is already seeing patchy fog down to LIFR/IFR levels, which likely will persist until around sunrise. As with previous fcst, kept a mention of MVFR at SAW overnight. While there is some potential for IFR or even LIFR, light northwesterly low- level flow is not typically favorable for such development. If fog does develop, it will dissipate within 2 hrs after sunrise. Light winds under 5kt overnight will become W to NW to around 10kt today, but wind will become NNE at SAW in the aftn. && .MARINE... Issued at 457 AM EDT Wed Sep 25 2024 Upper Michigan will remain under high pressure for the duration of the forecast period. Therefore, winds will remain at or below 20 knots through Sunday. The next chance for 20 to 25 knot winds will not be until Monday when the next system enters the region. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Jablonski LONG TERM...TDUD AVIATION...Jablonski/Rolfson MARINE...TDUD