Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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350 FXUS63 KDTX 141924 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 324 PM EDT Tue May 14 2024 .KEY MESSAGES... - High pressure brings mainly dry weather and near normal temperatures for Wednesday. - Scattered to numerous showers and possible embedded thunderstorms return Thursday night and Friday. - Warming temperatures to close out the work week and carry through the weekend, when highs likely reach into the lower 80s on Sunday. && .DISCUSSION... 700 MB moisture axis (5.5 g/kg of specific humidity)/right entrance upper level jet forcing triggering showers around M-46 to Saginaw Bay finally waning as low level northeast dry air also continues to undercut. Upper level low over the western Ohio Valley with associated low along the Ohio River, sliding east through tomorrow, with 500 MB ridge axis (568-570 DAM) building over the Central Great Lakes by Wednesday evening. Higher low level moisture content and still backed low level southeast flow this evening near the southern Michigan border will support a chance of light showers up to the I- 94 corridor, with a slight chance of weak thunderstorm right near the border. But otherwise, the low level dry air will continue to make further inroads tonight as low level northeast winds increase further. Still just enough residual moisture and modest cold advection around tomorrow to support decent amount of clouds, but highs still likely making a run aoa 70 degrees south of I-69, farther removed from the cool flow off Lake Huron. Upper level energy over the northern Rockies to get booted off to the east-northeast as 140 knot upper level jet tracks through southern British Columbia. Lead height fall center to track through Minnesota Wednesday night-Thursday, but additional weaker height falls/weak surface reflection to track through Central Great Lakes on Friday, supportive of unsettled/chance of rain showers to end the work week with the isentropic ascent/moisture advection. Marginal instability and modest instability will promote a slight chance of non-severe thundestorms as well. Large upper level ridge off the Pacific Northwest coast will sink south and become more west-east elongated, with some of the warm air over the Central Rockies breaking off and arriving over the Weekend, as 850 MB temps progged to exceed 15 C by Sunday, supportive of lower 80s for highs with favorable southwest winds. && .MARINE... Shower chances will remain possible into the early evening as high pressure continues to build in over the northern Great Lakes and pushes the frontal boundary south. There will continue to be a chance for rain and thunder overnight into Wednesday, mainly over Lake Erie, as low pressure moves eastward across the Ohio Valley. This low pressure system will reinforce northeast flow across all of the Great Lakes, building wave heights into Saginaw Bay and across the Lake Huron shoreline on Wednesday. Small Craft Advisories may be needed across Saginaw Bay and portions of the Lake Huron shorelines given wave heights building slightly above four feet. High pressure will continue to settle in over the Great Lakes on Thursday, relaxing wind speeds and subsequently wave heights. && .PREV DISCUSSION... Issued at 202 PM EDT Tue May 14 2024 AVIATION... Frontal boundary across Lower Michigan just south of the terminals bring east-northeast winds this afternoon of 6-10 knots. Pocket of clearing across the metro terminals has brought mostly clear skies prior to 18Z with lower VFR ceilings present across central Michigan and KMBS. Some diurnal cu are starting to develop in the clearing, which will also be where the best chances for scattered rain showers will be this afternoon. Have left any prevailing or TEMPO for rain showers out of the TAFs for now as latest guidance and observational data point toward activity possibly holding to the south/west. Any lower clouds should clear out later this evening with mid/high clouds remaining. Some lower clouds may return tonight, but have moderate confidence ceilings remain VFR. For DTW/D21 Convection...Little to no chance for thunderstorms with any showers developing near the I-94 corridor this afternoon given instability holding further to the south. May see scattered sub 5kft clouds both this afternoon and again early tomorrow morning. DTW THRESHOLD PROBABILITIES... * Low confidence in cigs aob 5000 feet this afternoon and early tomorrow morning. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...SF MARINE.......SS AVIATION.....AA You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.