012 FXUS63 KAPX 111043 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 643 AM EDT Thu Oct 11 2018 .NEAR TERM...(Today through Tonight) Issued at 252 AM EDT Thu Oct 11 2018 High impact weather potential: None. Pattern synopsis and forecast: Sfc low pressure was crossing eastern upper/eastern Lake Superior early this morning, with it's deep moisture and forcing continuing to peel eastward as a strong cold front was blasting through nrn Michigan. The heavier showers have transitioned to scattered light rains, and temperatures have started their road to a dramatic drop from the very warm readings over the last few days. The pressure gradient has been tightening with time, and SW/WSW winds have started to gust, and the low level cooling was trapping remnant moisture underneath a strengthening inversion, resulting in a large area of stratus/stratocumulus sweeping over the region. The low pressure will lift NE and head into Quebec today through tonight, and the low level cold advection will not stop from now all the way through tonight. Current temperatures in the upper half of the 50s and lower half of the 60s will fall into the mid and upper 40s for most areas this afternoon, then down into the middle to upper 30s most areas tonight. H8 temperatures will fall to 1c to -1c this afternoon and then to -4c to -6c tonight as winds shift from SW to NW. Moisture strips out sufficiently through daybreak to where all light rains will come to an end, but the deeper moisture on the backside of the departing low pressure will increase through the day and night. Inversion heights reach 5500-6000kft as the temperatures reach readings sufficient enough for deep overlake instability and the development of periodic and mainly light lake effect rains. This will primarily kick in this afternoon and continue through tonight. The pressure gradient will be tightening further over this time as well, with gusts of 30-35 mph being quite common later today. Although speeds will be dropping off tonight, it will still be gusty through the night. All-in-all...quite the transition from very warm and humid to windy damp and somewhat raw. && .SHORT TERM...(Friday through Saturday) Issued at 252 AM EDT Thu Oct 11 2018 ...Remaining much cooler with lake effect... High Impact Weather Potential...None expected. It remains plenty cold enough for more lake effect showers off of Lake Superior/Michigan through early Saturday. Lake/850 mb delta ts run in the upper teens to near 20. The mean 1000-850 mb winds average out between 280 and 290 degrees. Mean 850-700 mb relative humidity is close to 60 percent which isn't too bad. With 850 mb temperatures bottoming out at around -6 C could even see a few wet snow flakes in the higher terrain. Slightly milder air from an Alberta Clipper moving by to our north should put an end to the lake effect Saturday morning but there could be a few warm advection driven rain showers that creep in late in the day. .LONG TERM...(Saturday night through Wednesday) Issued at 252 AM EDT Thu Oct 11 2018 ...Unsettled and cool... High Impact Weather Potential...None expected. The pattern appears to remain rather active through the extended period with a continued train of short waves moving through the flow. This pattern will likely generate more lake effect/lake enhanced showers and it still looks marginally cold enough for rain showers to mix with or even change over to snow showers at times (especially at night). && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 636 AM EDT Thu Oct 11 2018 Low pressure and an associated strong cold front with it's deep moisture and forcing have exited east of nrn Michigan. This has resulted in better rains transitioning to some occasional drizzle early this morning, with MVFR CIGS overtaking the region. The MVFR CIGS will be the prevailing condition for primarily the NW lower airports through the forecast period, as well as periodic lake effect rain showers which ultimately develops via cold advection. The pressure gradient has tightened with gusty WSW winds in place, and the gradient will continue to tighten through today and this evening, before things relax a little overnight. Winds will be shifting from WSW to NW through the period with gusts to 30 kts being quite common at the airports today. In addition, scattered light lake effect rains will continue through the night.No VSBY restrictions foreseen. && .MARINE... Issued at 252 AM EDT Thu Oct 11 2018 Low pressure and it's deep moisture and forcing were all lifting NE and out of nrn Michigan, while a strong cold front was blasting through the region early this morning. The heavier rains have transitioned to spotty light rain, and the pressure gradient was tightening with time. The gradient continues to tighten through today and this evening before things relax a little overnight into Friday while high pressure dominates the Central Plains and inches our way. The strong cooling will lead to deepening overlake instability, and combined with the tightening gradient, gale strength wind speeds and periodic, mainly light lake effect rain showers will be common today into tonight. The higher pressure to our west will slowly take more hold on the Great Lakes Friday into Saturday, weakening winds, with the spotty lake effect light rains gradually diminishing. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY until 11 AM EDT Friday for LHZ348-349. GALE WARNING until 2 AM EDT Friday for LHZ345>347. LM...GALE WARNING until 2 AM EDT Friday for LMZ323-341-342-344>346. LS...SMALL CRAFT ADVISORY until 11 AM EDT Friday for LSZ322. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY until 11 AM EDT Friday for LHZ348-349. GALE WARNING until 2 AM EDT Friday for LHZ345>347. LM...GALE WARNING until 2 AM EDT Friday for LMZ323-341-342-344>346. LS...SMALL CRAFT ADVISORY until 11 AM EDT Friday for LSZ322. GALE WARNING from noon today to 2 AM EDT Friday for LSZ321. && $$ NEAR TERM...SMD SHORT TERM...AS LONG TERM...AS AVIATION...SMD MARINE...SMD