907 FXUS63 KAPX 190209 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 909 PM EST Wed Nov 18 2020 .UPDATE... Issued at 909 PM EST Wed Nov 18 2020 Southerly winds continue to strengthen across the Western Great Lakes region late this evening between strong high pressure centered along the Eastern US and a complex area of low pressure developing to the lee of the Canadian and US Rockies. Surface winds are gusting to 20 to 30 kts per several local and regional surface obs. Breezy conditions will continue thru the overnight hours and into Thursday. Dry low and mid level air will lend to a dry forecast...with only some thicker cirrus drifting overhead thru the night. Temps will only drop a few degrees overnight thanks to gusty winds and persistent mixing...with expected lows in the 30s. && .NEAR TERM...(Through Thursday) Issued at 329 PM EST Wed Nov 18 2020 High Impact Weather Potential: Lakeshore flood potential. Pattern Synopsis/Forecast: Early afternoon surface analysis shows a 1035mb high centered along the upper Ohio River...and a broad area of low pressure from Saskatchewan south into the northern Plains. Tight pressure gradient is in place in between these features over the Midwest and upper Great Lakes. Broad ridging aloft is advancing eastward from the Midwest...with strong low/mid level warm advection developing into Michigan. Plenty of high clouds spilling over the upper ridge and into northern Michigan at mid afternoon. Winds are starting to pick up with gusts to 20+ kts near Lake Michigan. Surface gradient will remain in place into Thursday with weakly anticyclonic flow aloft. Late in the day Thursday a cold front will approach from west ahead of height falls moving into the Dakotas. Primary Forecast Concerns: Winds will be the primary concern tonight into Thursday along with lakeshore flood potential. Strongest winds should be along the immediate shorelines where there is an onshore component. Inland areas with loss of heating will see some decoupling from the southwesterly low level jet (40-50+ kts) but there will still be gustiness due to mechanical turbulence. Inland wind gusts across northern Lower are expected pick up again Thursday with increased mixing...with gusts around 30 mph (a little higher near Lake Michigan and adjacent to Saginaw Bay). As far as lakeshore flooding issues will leave the headlines as currently configured. Don't see the need to extend the Lakeshore Flood Advisory into northern Lake Huron based on Great Lakes water level forecasts...best water level displacement should be occur from the Mackinac County Lake Michigan shoreline and from Grand Traverse Bay to the Straits in northwest Lower Michigan. Expecting a return to highs in the 50s for most areas Thursday afternoon. && .SHORT TERM...(Thursday night through Saturday) Issued at 329 PM EST Wed Nov 18 2020 High impact weather: None is expected. Primary forecast concerns/challenges: Pops late Friday into Saturday. Gusty winds Thursday evening will slowly diminish as we get into a looser pressure gradient (due to low pressure continuing to track well northeast of the region). A moisture starved cold front then moves across the region overnight into Friday morning. Steady cold air advection follows behind the front mainly later Friday into early Saturday. Perhaps a few showers with the front far north, otherwise increasing over lake instability may generate a few showers in northwest flow Friday night into early Saturday. High pressure builds in during the day Saturday so lake activity (if any) should come to an end. Mild Thursday night with lows in the upper 30s to mid 40s. Highs Friday ranging from the low 40s north to the mid 50s south, though temperatures will likely start to fall in the afternoon. Lows Friday night in the mid 20s to low 30s. Highs Saturday close to normal for once with the mid 30s to low 40s expected. .LONG TERM...(Saturday night through Wednesday) Issued at 329 PM EST Wed Nov 18 2020 High impact weather: Uncertain if there will be at this time. Extended models are in good agreement that low pressure passes by to our south Sunday into Monday (likely across the central Ohio Valley). This track would limit impacts on northern Michigan but it's still a few days away yet so that could change. Otherwise, another moisture starved cold front moves through the region on Monday. Models are then showing low pressure moving up from the south heading toward mid-week. This system could end up impacting the region but it is way too far out there into the future to have much confidence in any given track. Something to monitor for sure though. Forecast temperatures will be near normal through the period. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 627 PM EST Wed Nov 18 2020 Strengthening southerly low level flow between high pressure to our east and developing low pressure to our west will lead to LLWS across all Northern Lower Michigan TAF sites tonight into Thursday morning. Surface winds will remain from the south at 15 to 25 kts tonight into Thursday morning...shifting to the SW by Thursday afternoon. Solid VFR conditions can be expected for the next 24 hours. && .MARINE... Issued at 329 PM EST Wed Nov 18 2020 Winds and waves are increasing on Lake Michigan at mid afternoon as pressure gradient tightens up...with gales expected within Lake Michigan and Lake Huron nearshore zones south of Presque Isle Light tonight into Thursday. Small Craft Advisories have been posted for all nearshore zones outside of the warnings. Winds will diminish Thursday evening. && .APX WATCHES/WARNINGS/ADVISORIES... MI...LAKESHORE FLOOD ADVISORY until 4 PM EST Thursday for MIZ016-020- 025-031-095-096-098-099. LH...GALE WARNING until 11 AM EST Thursday for LHZ348-349. SMALL CRAFT ADVISORY until 7 PM EST Thursday for LHZ345>347. LM...GALE WARNING until 7 PM EST Thursday for LMZ323-341-342-344>346. LS...SMALL CRAFT ADVISORY until 5 PM EST Thursday for LSZ321-322. && $$ UPDATE...MR NEAR TERM...JPB SHORT TERM...AS LONG TERM...AS AVIATION...MR MARINE...JPB