Area Forecast Discussion
Issued by NWS Gaylord, MI
Issued by NWS Gaylord, MI
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569 FXUS63 KAPX 141338 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 938 AM EDT Wed Aug 14 2024 .KEY MESSAGES... - Potential for storms with heavy rain Thursday into Friday && .UPDATE... Issued at 937 AM EDT Wed Aug 14 2024 A little smoke/haze is well aloft across the region. A bit of marine/fog stratus on far northern Lakes MI/Huron is impacting some beaches, especially on US-2. Otherwise a quiet morning. 12Z APX observed sounding had 20C temps just 400ft off the surface, so we will warm up quickly. Minimal changes to max temps today, which will range thru the 80s. Enjoy...because changes arrive tomorrow and beyond. && .SHORT TERM /THROUGH TONIGHT/... Issued at 232 AM EDT Wed Aug 14 2024 Continued warm and dry today... High Impact Weather Potential...None. Large area of strong high pressure remains parked over most of the eastern half of the US early this morning...centered squarely over Michigan. Clear skies and light/calm winds are again lending to some patchy late night/early morning fog development across portions of our CWA...as temps cool into the 50s. High pressure center will gradually shift east of our state over the next 24 hours. Strong subsidence and dry air thru the column will continue to dominate our wx...lending to continued clear skies and warm mid August temps. Persistent light wind regime will again allow for lake breeze development this afternoon. High temps this afternoon will warm into the low to mid 80s...with overnight lows cooling into the upper 50s and lower 60s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 232 AM EDT Wed Aug 14 2024 PATTERN SYNOPSIS/FORECAST: Anomalous ridge centered over northern Canada/Hudson Bay. Ridge axis building across the central US toward the Great Lakes. General N-S line of troughing marching across the western US...though northern stream segment over Alberta is a bit ahead of the troughing over the Rockies. Ridge center over the Mid MS Valley with an upper trough over northern Mexico resulting in good return flow off the Gulf into the Lee of the Rockies, where the bulk of the convective activity is located as of 4-5z...along a BCZ generally stretching from Alberta down into the Lower MS Valley and Gulf Coast. Warm advection into the Upper Midwest...though upper flow is still northwesterly into the Great Lakes/Northern Michigan...with a little bit of moisture advection into the region attm. (Nowhere near as good of moisture as upstream, though.) Expecting ridge axis to move overhead today, with upstream troughing quickly shoving its way into the Upper Midwest going into Thursday. Ahead of this...expecting warm advection precipitation to develop over WI into parts of MI ahead of the primary surface low for Thursday. Better shot at widespread precipitation looks to be Thursday night...with the trough axis and upper jet more favorably poised over the region. Attendant surface low to slowly meander across northern Michigan Friday into Saturday, finally departing eastward going into Saturday night/Sunday...with a longer-duration rain and embedded thunderstorms to contend with in the meantime. Beyond this...some uncertainty in how quickly broader troughing departs the region...as the pattern begins to turn blocky, with ridge axis over the central US going into the weekend and beyond. Think some of this uncertainty will be related to how T.C. Ernesto ends up getting absorbed into the flow later this week. Additional uncertainty lies in how far south additional northern stream niblets are able to get to reinforce the troughing over our region for early next week. While there is at least some minor potential for a bit of unsettled activity early next week, think the primary difference will be how cool we remain, particularly if we end up with Canadian high pressure overhead (or not). Primary Forecast Concerns: Heavy rain potential Thursday into Friday...do have concerns with the anomalous moisture plume in the vicinity (likely overhead) combined with more synoptic forcing for a change with that trough and attendant surface low. This being said...think there is still a good chance the heaviest rainfall ends up being to our southwest Thursday afternoon/evening where the environment should be a little more favorable....though we should still see some warm advection activity, especially over our SW CWA toward TC, Manistee, Cadillac, as it slowly lifts northeastward through the night. Do have some concerns with the LLJ becoming a little more parallel to the boundary Thursday afternoon, with respect to training potential...so will have to keep an eye on this. In fact, this general idea of the warm front being in the vicinity through the period as the surface low likely tracks across northern Michigan suggests a concern for a swath of steady, more synoptic rainfall (rather than straight-up convective) to remain focused over parts of the area along and north of the low track over a longer duration (Thursday night into at least Friday afternoon, if not longer)...which could certainly lead to some hydro concerns if this verifies. Attm, do have some moderate confidence in this idea...with some probabilistic guidance suggesting a greater than 40 percent chance for an E-W swath of at least an inch in 24 hrs somewhere across northern MI. Guidance has been hinting at this idea for the last couple days, though the position of this swath has shifted from closer to the Straits last night to closer to M-32 attm...so will have to keep an eye on this. Storm potential Thursday into Friday...guidance derived soundings show the presence of elevated instability, particularly Friday morning into Friday afternoon. Even some potential that the instability (perhaps 500-1000 J/kg CAPE?) could become surface based over parts of the area, particularly in the warm sector, Friday afternoon. Signals are not impressive with regard to deep layer shear up here, which is fortunate...but certainly think we could have some storms around through the day. Even if we never break out of the clouds (and especially if we do break out of the clouds). && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 645 AM EDT Wed Aug 14 2024 Strong high pressure center will slowly drift eastward out of Michigan today and tonight...but strong subsidence and dry air thru the column will maintain mostly clear skies and prevailing VFR conditions thru 12Z Thursday. Persistent light wind regime will again allow for lake breeze development by this afternoon. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...JZ SHORT TERM...MLR LONG TERM...FEF AVIATION...MLR