479 FXUS63 KAPX 101917 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 317 PM EDT Thu Sep 10 2020 .NEAR TERM...(Through Friday) Issued at 316 PM EDT Thu Sep 10 2020 ...Clearing tonight with some frost possible... High Impact Weather Potential: Minimal, some inland frost possible...if we can get rid of the clouds. Pattern Synopsis/Forecast: Larger scale troughing is across central/eastern Canada and northern Great Lakes and deep cutoff low over the four corners region of the CONUS. Upper jet core stretches from the northern lakes eastward across Quebec, while confluent flow axis stretches from Iowa across southern Lower Michigan. Strong upper level divergence and deformation continues to produce a widespread area of rainfall across Iowa into Wisconsin and Illinois, some of which has/is getting drawn eastward across central Lower Michigan, just south of the M-55 corridor and along the confluent flow axis and tight lower level thermal gradient that is still in place through Lower Michigan. At the surface, elongated high pressure spans much of the Midwest and across the northern lakes with associated deep layer dry air continuing to slowly build across northern Michigan. Low level moisture/cloud cover lingers across northern Michigan bolstered by daytime heating and NNE flow off the relatively warm lakes...as well as some thinker mid and high cloud cover also streaming across Lower michigan. Surface high pressure and deep layer dry air will continue to build into the state tonight into Friday bringing overall quiet weather. Details: As mentioned, cloud cover has remained entrenched across most of the forecast area today, bolstered by heating of the day and flow off the lakes and thicker mid/high cloud cover also streaming through the region. But with loss of heating and high pressure/dry air continuing to build east/south into the region, we should be able to thin/clear out a good amount of the cloud cover as we go through the evening particularly across the northern part of the forecast area. But that said, with the lack of mixing today, damp boundary layer conditions and thinning clouds tonight, fog/stratus development is a strong possibility as we go through the night. Frost potential: Lower to middle 30s low temps and some frost development are possible across our inland cold areas later tonight, although that will of course depend on the degree of clearing we see as well as any fog/stratus development. I will continue with patchy-areas of frost in the forecast, but just not confident enough on widespread frost development to warrant a headline at this time. Friday: Surface high pressure/dry air should finally take hold on the region leading to a good amount of sunshine (after any morning fog/stratus) and high temps clawing back through the 60s. && .SHORT TERM...(Friday night through Sunday) Issued at 316 PM EDT Thu Sep 10 2020 ...Rain showers Late Saturday into Early Sunday... High Impact Weather Potential: Minimal. Synopsis: Current main feature is still the big cut-off low hanging out near the four corners. Closer to home an 80-90 kt jet is overhead as a shortwave passes through southern Ontario. We still have a frontal boundary in the Ohio Vally that is pushing slowly off to the south as high pressure works into the Great Lakes. By Friday night into Saturday the cut-off starts getting reabsorbed into the main flow and treks toward the Great Lakes, spurring showers late Saturday into Sunday. Details: Surface high pressure pushes east Friday evening, and clouds return from the southwest as moisture pushes north ahead of the next system. The cut-off low weakens and becomes an open wave overnight across the northern Plains...the attendant surface reflection will be a broad weak area of low pressure with an occluded front pushing through the northern Mississippi Valley. Weak broadscale lift nudges into our region Saturday morning, and PWATs rise through the day (up to 1.4" in the afternoon, and possibly even more overnight) as warm moist air surges north over the stationary/psuedo warm front. Widespread rain chances remain on the low side through the morning and early afternoon, but ramp up heading into the evening and especially overnight as the center of the occluded low passes Michigan, -DivQ strengthens, and bulk shear increases to 40-50 kts with the arrival of the upper level wave moves in. Even with meager instability (couple hundred Joules) there's potential for some stronger updrafts, and at the very least some thunder through the overnight hours. Isentropic lift and some wrap around moisture will lead to additional shower chances through Sunday morning. This will be helped along by a narrow corridor of moisture ahead of another cold front sweeping across Michigan through the day. Behind this front temperatures would be cool enough over the water to produce light scattered showers downwind of the lakes if they can overcome the dry low levels in the early afternoon. At the very least we should have some lingering clouds off the lakes in the afternoon. Otherwise we enter a dry period heading through the evening and overnight into the next work week. High temperatures through the weekend will be mainly in the mid to upper 60s. && .LONG TERM...(Sunday night through Thursday) Issued at 316 PM EDT Thu Sep 10 2020 Early next week the jet becomes more zonal and lifts to our north. At the surface high pressure dominates the region into Tuesday, leading to dry and mild conditions with temperatures returning to near normal, with highs near or slightly above 70. The next system moves to our north Tuesday night, dragging a cold front through Michigan late Tuesday/early Wednesday...bringing our next chance of showers midweek. Plenty of uncertainty beyond this regarding surface features late next week, ranging from a strong high over the upper Mississippi Valley to a surface low. As it stands, seems reasonable to keep low chance pops in. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 316 PM EDT Thu Sep 10 2020 Pesky MVFR cloud cover remains draped across much of northern Lower Michigan this afternoon despite high pressure and deep layer dry air building into the region. Will have to wait until this evening and loss of heating to finally further thin out the cloud cover and improve things back to VFR. But with that, some fog development is possible later tonight into Friday morning. Solid VFR weather is anticipated for Friday. && .MARINE... Issued at 316 PM EDT Thu Sep 10 2020 Light winds/waves anticipated tonight through Friday night. Some gustiness returns on Saturday, although winds/waves are expected to remain below headline criteria. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ NEAR TERM...BA SHORT TERM...STJ LONG TERM...STJ AVIATION...BA MARINE...BA