


Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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054 FXUS63 KDTX 140752 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 352 AM EDT Mon Jul 14 2025 .KEY MESSAGES... - A sunny and warm start to the week with less humidity today and Tuesday. - Showers and thunderstorms return Wednesday through Thursday. Heavy rainfall becomes the primary weather hazard during this time. - A cold front sweeps through the area early Friday followed by cooler and less humid air next weekend. && .DISCUSSION... Great Lakes high pressure is weak but established enough to maintain dry weather and slightly less humid conditions compared to recent days. Larger scale subsidence follows the eastward 500 mb trough departure this afternoon leaving zonal northern stream westerlies displaced well north across Canada. The resulting excellent prospects for full sun support leaning high temperatures toward the warm end of the guidance range, in the upper 80s with a few reports touching 90. Relatively comfortable temperature and humidity conditions continue tonight as surface Td holds below 70, and this is now projected to be the case for most of Tuesday. HREF mean surface Td available out into Tuesday evening holds in the 60s as does the usually bullish NBM guidance. This makes a slight uptick in temperature easier to take with a few more 90s expected for afternoon highs. Tuesday ends up being the transition day into increasing SW flow ahead of the next Plains frontal system that is set to return an active late week period of showers and thunderstorms to SE Mi. The 14/00Z deterministic solutions are in good general agreement on the large scale pattern by 12Z Wednesday. The mid time range projections bring the current Ohio valley front and associated moisture transport back into Lower Mi Wednesday morning. Strong 850-700 mb theta-e advection quickly lifts PW back to about 1.75 inches and sustains numerous showers and thunderstorms across the area during the day. This phase helps fully establish the large scale moisture axis out ahead of the impressive frontal system stretching from Quebec to the upper Midwest and into the central Plains. There is abundant model QPF and vorticity evidence of convective clusters occurring along and ahead of this system as it advances eastward Wednesday night and Thursday, and across Lower Mi centered on Thursday night into Friday morning. At this point in the forecast, heavy rainfall is set to be the primary hazard vs severe thunderstorm potential. Consensus of extended time range projections then bring the front through SE Mi Friday morning for a chance to start off next weekend with cooler and less humid conditions. && .MARINE... A high pressure system will bring light winds and mostly dry weather today into Tuesday, outside for a very low chance of a stray shower across northern Lake Huron this afternoon and evening. The next chance for showers and thunderstorms will enter Wednesday through early Friday as a series of upper-level disturbances and cold front pass over the Great Lakes. This brings the chance for some localized stronger wind gusts with any thunderstorm development, but otherwise winds remain light given the weaker pressure gradient in place. && .PREV DISCUSSION... Issued at 1202 AM EDT Mon Jul 14 2025 AVIATION... VFR conditions expected through this TAF period. Winds will remain light and generally out of the west to southwest becoming light and variable at times tonight. High clouds will clear out through the morning hours leaving clear skies for much of today. Pockets of hazy skies from Canadian wildfire smoke will remain over the area through today, especially to the north. This may bring the occasional reduction in VSBYs to MVFR. For DTW/D21 Convection...No thunderstorms expected this TAF period. THRESHOLD PROBABILITIES... * None. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...BT MARINE.......AM AVIATION.....AA You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.