Area Forecast Discussion
Issued by NWS Gaylord, MI
Issued by NWS Gaylord, MI
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929 FXUS63 KAPX 231438 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 1038 AM EDT Mon Sep 23 2024 .KEY MESSAGES... - Rain chances return late tonight into Tuesday - Mild and quiet weather mid and late week && .UPDATE... Issued at 1037 AM EDT Mon Sep 23 2024 Disturbance from yesterday now largely off to our east...though PV strand drapes back over us in its wake...extending back to IA where the next niblet is currently located...as yesterday`s boundary gets strung out to our south: surface low over northern Lake Erie with cold front extending back to OK/MO...and warm front from this low outlining the eastern side of the Appalachians through the Mid Atlantic region...with another cold front stretching northward to Hudson Bay. Moisture trapped south/east of this boundary; cool and dry advection in its wake...as surface high pressure settles in here beneath confluence aloft. 850mb temps here between 5 and 10C this morning; some lingering boundary layer moisture present as well...with a stratus deck/fog starting to mix out into more of a diurnal convective rolls look...particularly off the waters of Lake Huron and even GT Bay, where overlake instability is playing a role in cloud cover as well. Weak PV strand stretching by north of Lake Superior this morning...with much better PV noted even further north (cool bowling balls of PV energy through Ontario, training back into Manitoba). Otherwise...surface high pressure encompasses the bulk of the central US attm...with some disturbances between it and an upper high focused just off the Pac NW coast; potent 120-140kt upper jet cresting this ridge into central Canada. Expecting things to remain largely quiet and slightly lake-cloudy in a few spots today...with high pressure hanging out overhead. Looking at much more seasonable temps today for late September (normal highs in the mid to upper 60s; we should be somewhere in this vicinity for a change). && .SHORT TERM /THROUGH TONIGHT/... Issued at 339 AM EDT Mon Sep 23 2024 Pattern/synopsis: 1009mb low pressure is near the St Clair River. Most precip is east thru north of this low; synoptic precip has largely exited northern MI. There could be a touch of lingering DZ or a sprinkle where low clouds still linger (in northern lower MI). Forecast: High pressure will s and sw-ward into northern MI, as the low departs to the e and se. This will push drier air into the region. Widespread cloud cover is already se of a ROgers-CAD line. Our pressure gradient is reasonably tight, but that hasn`t stopped some inland locales from decoupling and seeing some fog. And a few lake streamers are noted as well. Once we get past sunrise, diurnal heating may allow for some stratocu, especially where the lakes are contributing moisture. But we will mix up into increasingly drier air today, and cloud cover should decrease with time. Tonight, a shortwave trof lifts ene-ward toward the sw Great Lakes. As it does, cyclogenesis occurs a bit south of lower MI. Our low-level flow becomes easterly, and will start tap into a moisture plume present over the far eastern lakes. Truly deep moistening will remain downstate (though edging northward). But we look to become cool and moist enough for the lakes to become more active. Cloud cover will generally increase from se to nw. Ne lower MI will likely see some rain showers move in off of Lk Huron overnight. There are also signs in guidance of an inverted surface trof developing northward into nw lower MI, with associated moisture pooling. A few showers could also be generated here, especially very late. Max temps today mid 60s to lower 70s. Lows tonight 40s to near 50f. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 339 AM EDT Mon Sep 23 2024 Pattern Synopsis and Forecast: Current split flow pattern over North America with northern branch flow over the Great Lakes region will continue another day of cool fall-like temperatures. Embedded troughing along both north and southern branch flow will keep us somewhat active early in the period, before things quiet. Embedded shortwave troughing currently over the central plains will progress easterly and make its way to the Mid-Mississippi/Ohio Valley by Tuesday. While the majority of energy will be south of the CWA, scattered showers can still be expected on Tuesday. Upstream ridging currently over the northern Pacific will make its way to the midwest by the Thursday timeframe, resulting in surface high pressure and quiet weather for the remainder of the forecast period. Primary Forecast Concerns/Key Messages: Scattered showers return this Tuesday. Surface high pressure and quiet weather builds this Wednesday: No impactful weather is expected through the entirety of the long term period. Only active weather will be at the start as aformentioned troughing settles into the Ohio Valley. Relatively weak forcing dynamics along with a lack atmospheric moisture will keep rainfall amounts low. A general tenth or so of QPF can be expected this Tuesday before ridging begins to build around the Wednesday timeframe. Midlevel southern branch riding will keep conditions quiet and dry for the remainder of the long term. Temps are expected to return to above average for late September with highs in the low to mid 70s for most locations. Looking ahead towards the end of the week, ensembles do depict chances of precip returning to the Great Lakes region, but discrepancies in guidance will keep chances along with messaging pretty minimal at this time. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 637 AM EDT Mon Sep 23 2024 Early morning fog and lower clouds will quickly burn off (by 14Z), with VFR conditions for the rest of the day and evening. Clouds increase late tonight ahead of our next system. MVFR cigs are expected at APN very late tonight, and a few showers are possible at MBL/TVC/APN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 2 PM EDT this afternoon for LHZ348- 349. && $$ UPDATE...FEF SHORT TERM...JZ LONG TERM...SJC AVIATION...JZ