Area Forecast Discussion
Issued by NWS Gaylord, MI
Issued by NWS Gaylord, MI
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943 FXUS63 KAPX 291715 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 115 PM EDT Wed May 29 2024 .KEY MESSAGES... - Chances of frost tonight and possibly Thursday night. - Slowly increasing chances for showers and thunder later this upcoming weekend into next week. && .SHORT TERM /THROUGH THURSDAY/... Issued at 313 AM EDT Wed May 29 2024 Pattern Synopsis / Forecast: While the upper-level flow is trending more neutral overall, forecast area remains slightly under the influence of the mean troffing over eastern North America. The better forcing and moisture within the trof has shifted east of the area, leaving cooler than normal temperatures as the primary impact. The upstream upper-level ridging will stay west of the area through the short-term forecast period, but an associated area of surface high pressure will start pushing into the area by late tonight. Northerly low-level flow to the east of the approaching surface high is tapping a very dry air mass over central Canada. This drier air mass supports RH values during peak diurnal mixing this afternoon to fall to around 25%. RH values this low would normally spark fire weather concerns, but winds will be light enough and the significant rains earlier this week have fuels relatively moist (especially post green-up). A more immediate concern with the dry air mass is the potential for cold overnight lows tonight given the good radiational cooling conditions (light wind and clear skies). At this point overnight lows look likely to stay above freezing but overnight lows inland are expected to fall into the mid 30s and produce areas of frost. Plan to hold off on any Frost Advisory at this time per coordination with surrounding offices, but an advisory is certainly a possibility later today. Temperatures today are expected to top out in the 60s, with overnight lows falling into the mid-upper 30s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Issued at 313 AM EDT Wed May 29 2024 Pattern Synopsis / Forecast: 500mb ridge axis (driven by troughing over the Canadian prairies) set to move overhead over the course of Thursday and Friday, with surface high pressure set to bring about dry conditions to close out the work week. Highs expected to be in the upper 60s to mid 70s Thursday, moderating to the lower to upper 70s by Friday. Large differential heating between the warmer land and the colder Great Lakes will generate a prime setup for lake breeze processes to commence, thus locally cooler on the immediate lakeshores both days. The larger trough will stall out and flatten over the Prairies, with surface high pressure being forced to the east, drumming up warmer southerly surface flow for the weekend. 500mb ridge axis will be forced well to our east as more of a WSW to ENE zonal flow beneath the aforementioned flattening trough commences. Though moisture return will be rather slow to start the weekend, potential for weak convective waves to ride this flow into the upper Great Lakes will provide perhaps a shower or thunder chance, though most spots probably hold dry much of the weekend as highs spike into the 70s and 80s by Sunday. Warmth really kicks in on Monday as another ridge axis moves into the Great Lakes ahead of another trough riding the zonal flow regime. With 850mb temps spiking potentially as high as 16C, could result in highs well into the 80s Monday. Aforementioned second trough will advance into western Lake Superior, lifting northward and flattening out as it interacts with the ridge axis. Proximity of this feature likely brings the best chance for showers and thunder over the duration of the forecast period Monday into Monday night. Primary Forecast Concerns: Thursday Night Frost: Confidence in widespread frost potential Thursday night lowering somewhat at this juncture. Daytime temps in the 60s and 70s on Thursday, coupled with shorter nights will force diurnal processes that can tank temperatures to work rather quickly... and despite decoupling winds and clear skies, most spots outside of perhaps the more typical icebox locales (Raco, Trout Lake, Grayling, Mio, etc) in the interior will largely remain in the upper 30s. Weekend Shower / Thunder Chances: Rather unimpressive wave progressions along the zonal flow regime to begin with, coupled with the core of forcing being kept north into western Lake Superior and northern Ontario does not conjure up much in the way of hope for widespread showers and thunder across the region for the weekend. Dewpoints will increase some (into the 40s and lower 50s), which could be just enough to drum up a few hundred joules of instability Sunday. Overall lack of forcing probably limits convection on Sunday to lift generated from additional lake breeze processes owing to overall weak surface flow / more strong differential heating. Deeper moisture (dewpoints in the upper 50s) will arrive Monday and Tuesday, and with the passing wave to the north, a semblance of somewhat better forcing could drum up better shower and storm chances. Will have to see how the convective charge within this wave evolves to get a better grasp on timing and intensity of any resulting showers and storms across northern Michigan, which will be examined in the coming forecast cycles considering this is 5-6 days out from now. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 114 PM EDT Wed May 29 2024 VFR through the period (and likely the next several periods) with high pressure at the surface and aloft. Light winds. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ SHORT TERM...PBB LONG TERM...HAD AVIATION...JHV