Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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381 FXUS63 KMQT 081146 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 746 AM EDT Wed May 8 2024 .KEY MESSAGES... - Rain showers mainly end this morning as the low pressure system departs. However, slight chances for light showers continue over the west into this afternoon. - Multiple passing low pressure systems will keep rain chances in the forecast into early next week along with thunderstorm chances both Sunday and Tuesday. && .SHORT TERM /THROUGH THIS AFTERNOON/... Issued at 519 AM EDT Wed May 8 2024 Current RAP analysis has the shortwave and sfc low responsible for the line of showers yesterday and the current comma head of showers lighting up the radar over the east and Lake Michigan well stacked over the Mackinac Bridge. As these two features move east today toward New England, the heavier showers will move east with it this morning. Additional accumulations this morning are expected between a few hundreths and 0.3", higher in the east half of Upper MI. Although the better precip moves out this morning, slight chances for low impact light showers/drizzle continues throughout the day. Best chances for precip (~15-20%) are over the east as PWATs show decent moisture around 0.75" and some weak q-vector convergence remains. Confidence in timing or exact location of these showers is low as PoP solutions among the CAMs were not in agreement. Best consensus was over the western half of the UP earlier in the afternoon, save for the Keweenaw. Additional accumulations after sunrise likely will only be a few hundreths at best, so no real impacts are expected. Any lingering precip should end by this evening as drier air advects in from the north. With northerly winds off Lake Superior today, highs near the lake will stay lower in the upper 40s to mid 50s. The interior and southern half of the UP are expected to see highs peak in the upper 50s to mid 60s. && .LONG TERM /TONIGHT THROUGH TUESDAY/... Issued at 452 AM EDT Wed May 8 2024 Periodic rain chances will be common throughout the extended period as a series of low pressure systems pass through Upper Michigan. Initially though, the period will start in a bit of a lull as a Northern Plains closed mid-level low continues to slide southeastward while opening up and drifting around the Lower Midwest. Meanwhile, the associated surface low ahead of it will drift through the Ohio Valley. So, what this means for much of the UP is a dry forecast Wednesday night through Friday morning. Earlier model runs were originally taking more of a northern track with the aforementioned disturbance. But, the southern track has come to fruition, thus rain chances have been removed from the south and east from Thursday. And strengthening subsidence/ridging will keep the forecast dry through Friday morning. By Friday afternoon, mid-level ridging will begin to break down as the next shortwave dives southeast from northern Saskatchewan. With an uptick in isentropic ascent after Fri 18Z, rain showers will overspread the UP from west to east through the evening, quickly tapering off after Sat 06Z with loss of dynamics. In addition, will briefly carry thunderstorm mention over the west-southwest portions of forecast area Friday evening with that sector falling under the left exit region of a weak upper level jet, but that is low to moderate confidence at this point. After some lingering 10-20% rain chances through Saturday afternoon (central and east) in association with departing shortwave, there will be a lull in activity Saturday night as brief ridging once again builds over the UP. Again though, the dry weather will be short-lived as focus turns to a series of systems traversing first northern Manitoba and then southern Saskatchewan/Manitoba. Showers and thunderstorms will accompany both systems on Sunday and again Tuesday. And, it is still a bit early, but instability and vigorous cold fronts could be enough to generate some strong thunderstorms both days. These will be targets of opportunity to monitor, especially Tuesday afternoon/evening as high temperatures climb into the low to mid 70s. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 125 AM EDT Wed May 8 2024 The low pressure system over the eastern UP departs eastward today, resulting in improving flight conditions. IWD and SAW may see some patchy fog yet in the next hour or two with light winds and ample moisture leftover from previous precip. With daytime heating, this is expected to mix out as cigs gradually improve to VFR. Downslope northeast flow will keep CMX at VFR throughout the 12Z TAF period. SAW and IWD also may see some isolated light showers/drizzle this afternoon. However, mention of afternoon precip was left out of the TAFs with low confidence in timing or location. && .MARINE... Issued at 521 AM EDT Wed May 8 2024 Northeast winds of 25 to 30 knots will prevail today and tonight mainly over western and central portions of Lake Superior. After that, despite wind shifts due to multiple low pressure systems, winds will remain below 20 knots through Sunday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Small Craft Advisory from 11 AM EDT /10 AM CDT/ this morning to 8 PM EDT /7 PM CDT/ this evening for LSZ240>242. Small Craft Advisory from 11 AM this morning to 5 PM EDT this afternoon for LSZ243-244. Lake Michigan... None. && $$ SHORT TERM...Jablonski LONG TERM...TDUD AVIATION...Jablonski MARINE...TDUD