028 FXUS63 KAPX 191737 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 137 PM EDT Tue Oct 19 2021 .UPDATE... Issued at 1059 AM EDT Tue Oct 19 2021 Not a whole lot to update with high pressure to our south keeping the region mostly sunny and unseasonably warm today. Southwest winds will pick up some and should average between 10 and 15 mph with gusts to near 20 mph this afternoon. Highs of well into the 60s to the low 70s. && .NEAR TERM...(Today through Tonight) Issued at 351 AM EDT Tue Oct 19 2021 ...Very Mild Mid-October Day... High Impact Weather Potential: None. Pattern Synopsis/Forecast: Sharp mid level ridge in the process of building into the area early this morning. Per the usual, surface reflection running just a bit ahead of its mid level parent, with high pressure extending from the southeast states north into northern Michigan and eastern Lake Superior. Attendant deep layer subsidence regime and dry atmospheric column has resulted in a mostly clear and somewhat chilly night...with current readings dropping into the 40s, and even a few of our typical colder locations falling into the 30s (still at least a few degrees above normal however). Mid level ridge expected to remain centered across the area today and tonight...although heights will slowly lower tonight as troughing digs across Ontario. Weak cold front tied to this latter feature will make slow southeast progress, likely pushing across eastern upper Michigan later tonight. Primary Forecast Concerns/Challenges: Main focus centered on temperature trends (or more precisely...just how warm to go today). Details: Mid level ridge and attendant subsidence regime/dry atmosphere will result in mostly sunny skies today. Bigger story will be temperatures, with increasing southwest winds on north side of slowly retreating surface high advecting an unseasonably warm airmass into the Great Lakes. Dry low level environment and sun-filled skies easily support mixing to at least H9 level...where temperatures will be in the lower teens Celsius. This supports highs well up into the upper 60s and lower 70s...with those warmest readings expected across northeast lower Michigan where downslope influences will be maximized. For a comparison, normal high temperatures for today's date are in the lower to middle 50s. However, highs today will fall well short of any records, which are mostly in the upper 70s to near 80 for a climate locations. Weak cold front slowly works southeast out of northern Lake Superior tonight, likely reaching vicinity Tip of the Mitt counties by sunrise Wednesday. All deep layer forcing is well removed to the north, and atmosphere only partially moistens ahead of the front. Both of these support dry conditions prevailing, although will likely see some increasing clouds...particularly across the north. Again, bigger story will be the continuation of well above normal temperatures...with those increasing clouds and maintenance of pre- frontal southwest winds likely keeping at least portions of northern lower Michigan from dropping out of the 50s. && .SHORT TERM...(Wednesday through Thursday night) Issued at 351 AM EDT Tue Oct 19 2021 High Impact Weather Potential: Minimal attm... Pattern Synopsis/Forecast: Wednesday morning...complex upper level pattern will still be in place...with troughing to the west, north, and east of us. Ridging will continue to fade southeastward as the upstream trough over the northern Plains progresses in our direction with time...allowing an anomalously moist airmass to flood into the region yet again on southwesterly flow through the column. Meanwhile...strong troughing to our north will continue to dive southward and perpetuate a zonally-oriented surface boundary across our northwoods...keeping us in the focus for precipitation through much of the short term. That Plains shortwave should move through during the day Thursday...and as it passes through...will look for cold advection (generally associated with the upper low to our north as it begins to pivot down our way a bit) to bring a much cooler airmass into the region. Falling temps aloft Thursday night may even support lake effect shower development in some locations. Primary Forecast Concerns: Rain/thunder potential Wednesday into Thursday...lake effect Thursday night.... Surface cold front extending from near Hudson Bay on the Manitoba/Ontario border as of 3z/19 southwestward into the northern Plains will become a focal point going into the short term portion of the forecast...as it looks to drape into the Straits area by Wednesday morning or so. As this front continues to slowly sink southward through the day, reinforced by cold advection to its north thanks to a 100+ kt upper-level jet max and surface high pressure...will look for it to stall out in the presence of southwesterly flow and warm, moist advection both at the surface and aloft ahead of the system in the Plains. The Plains low looks to progress eastward, more or less along this boundary, through Wednesday night and into Thursday...allowing the boundary to stall out in the vicinity of Northern Lower until such a time as the winds begin to turn more northwesterly again on the backside of the surface low and cold advection is allowed to proceed into the region unfettered...which looks to happen through the day Thursday into Thursday night. North of this zonally-oriented boundary on Wednesday...it should be cooler, though potentially with some mid-low clouds overhead (makes sense given some mid-low level moisture in place behind the same boundary at 0z/19 across the western Canadian Prairies) while areas south of the boundary will be in the warm sector of this system and should remain at least somewhat above normal for this time of year. With that anomalously moist atmosphere advecting in through the day (pwats again surging into the ~1" range, which is near the high end of climo for this time of year)...will look for top-down saturation to progress through the day...resulting in precipitation beginning towards the middle of the day at the earliest...though can't entirely rule out some stray stuff moving in during the morning hours. Better chances for rain, however, should arrive later in the afternoon/evening and so on as better synoptic forcing moves into the area with the approach of that shortwave aloft from the Plains. Suspect this will be more of a stratiform rain environment, given the lack of instability (save for some marginally steeper lapse rates aloft as the air aloft begins to cool with the approach of the upper level troughing)... though some guidance would like to bring in a few hundred joules of MUCape in the form of elevated instability, thanks to a stable layer in the mid-levels (beneath the aforementioned steeper lapse rates) given that warm advection ahead of the surface low/shortwave aloft. Will look for the best rain chances to be along and north of the front, where warm and moist air would be rising up over the cooler air near the surface. The overall idea of stratiform precip with potential for a rumble of two should continue to be the case through the night Wednesday into Thursday, until the surface low passes by at some point Thursday afternoon. Wrap-around moisture behind the low...in combination with 850mb temps falling below zero over sufficiently warm lake waters...should allow things to switch over to a more showery, lake- effect regime Thursday into Thursday night...though some heavier stratiform precip may be possible right behind the low itself Thursday afternoon. Will have to keep an eye on this. Despite cooler and drier air funneling into the region Thursday night, thanks to a reinforcing cold front associated with the trough to our north...with the lake as a source of moisture and instability...will be looking for that lake effect potential to start to pick up through the night. Thursday into Thursday night may be the first taste of real cold that we've seen thus far this season...with breezy conditions behind the departing and deepening surface low only adding to the chilly punch. .LONG TERM...(Friday through Monday) Issued at 351 AM EDT Tue Oct 19 2021 High Impact Weather Potential: Minimal attm... Pattern Synopsis/Forecast: A decent amount of uncertainty is in place for the coming weekend and beyond...as there is a lot of model spread (and intra-model spread) in the handling of an anomalously strong trough over the eastern Pacific (which should be fed by a strong East Asian jet, stretching from Japan all the way to the West Coast of North America). It appears that between that trough, our trough, and the anomalous ridge that is progged to develop across Northern Canada...an omega block type pattern is ahead for the weekend. This should keep us on the cooler side of things for the most part, thanks to the downstream troughing side of the block hanging out over us. Various niblets passing through the flow would act to enhance any lake effect chances that occur (an idea with some merit, given the cool air aloft over the region and potential for over-lake instability)...though there is still some uncertainty in these little niblet-y details. Model solutions quickly diverge going into Saturday/Saturday night, in just how the pattern shifts (or doesn't) going forward. Even so...if everything lines up correctly (niblets pass through the region late in the day into the overnight, allowing for precipitation to take place during the colder nighttime period)...wouldn't be shocked to see the white stuff start to fall in some areas...though attm...suspect we'd be hard pressed to accumulate much at all, with the soil still warm (soil temps this evening at the office were in the low 50s 2" below the surface). && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 134 PM EDT Tue Oct 19 2021 High pressure will move slowly off to our east through tonight. A weak, moisture starved cold front will then drop down from the north Wednesday morning. Low pressure is expected to bring showers just beyond the taf period late Wednesday into Wednesday night. VFR cigs/vsbys through the period. Southwest winds of 5 to 10 knots through tonight shifting into the west behind the front Wednesday morning. && .MARINE... Issued at 351 AM EDT Tue Oct 19 2021 Southwest winds will be on the increase today as surface high pressure slowly retreats to our southeast. Increasingly stable over- water conditions within an unseasonably warm airmass will likely negate small craft advisory conditions from developing. Weak cold front slowly drops southeast across Lake Superior and eastern upper Michigan later tonight, swinging the winds around to northwest as it passes. Otherwise, sub-advisory level southwest winds will continue. Front essentially stalls/washes out across lower Michigan on Wednesday...resulting in mostly light winds. Dry weather is expected today and tonight, with increasing rain chances Wednesday and Wednesday night as low pressure pushes toward the region. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...AS NEAR TERM...MB SHORT TERM...FEF LONG TERM...FEF AVIATION...AS MARINE...MB