Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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672 FXUS63 KDTX 150736 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 336 AM EDT Wed May 15 2024 .KEY MESSAGES... - Few lingering light showers south of I-94 this morning. Otherwise dry weather returns as clouds gradually clear north to south today. - Scattered to numerous showers and possible embedded thunderstorms return Thursday night and Friday. - Active pattern holds this weekend into the beginning of next week with warmer temperatures and shower/storm chances most days. && .DISCUSSION... Surface low pressure and parent mid-level trough remain over the Ohio Valley today before shortwave energy shifts east to reorganize into a mid-Atlantic coastal low. Locally, the slow departure supports continued a low chance (~15-25%) for scattered showers over areas along/south of I-94- greatest potential focused over Lenawee/Monroe counties. For the rest of the CWA, dry air advection amidst NE flow lends to a gradual though steady north-to-south clearing of cloud cover with areas north of I-96/I-696 likely experiencing mostly sunny-partly cloudy skies by late this afternoon (sunniest north). Seasonably average day for inland areas today as high top out in the low to mid 70s. Areas down wind of Lake Huron, ie Tri-Cities/Thumb, hold cooler in the 60s with areas closest to the shoreline likely struggling to get out of the 50s. Mid-level ridging in advance of another mid-upper trough ejecting out of the Rockies slides across the central Great Lakes Thursday. Pleasant day as winds shift to the southeast in response allowing most areas to see temperatures reach the mid 70s even with increasing clouds through the day. These clouds mark the lead edge of height falls tied to the aforementioned Rockies trough that will fully expand over southern lower MI Thursday night and Friday. Weakening surface low pressure lifting through the upper Midwest sends a washing out cold front toward the region supporting shower chances overnight into Friday morning. Thunder chances are low but non-zero as mid-range solutions advertise a few hundred J/kg of elevated instability attempting to creep into the state. Mid-level trough settles over the Great Lakes daytime Friday providing upper level support for afternoon shower and thunderstorm redevelopment. Muddled pattern going into this weekend as separate northern and southern stream waves traverse the central CONUS. Southern stream wave tracks through the Ohio/Tennessee valleys Saturday maintaining weak mid-level troughing over the southern Great Lakes. This offers a shot for diurnal pop-up showers/storms Saturday afternoon with long range models suggesting a few to several hundred J/kg of MLCAPE to develop during peak heating. Northern stream wave flattens the western ridge and largely prevents its significantly warmer airmass over the Southwest/Plains from reaching into the Great Lakes as the trough`s associated weak cold front is instead driven through the Great Lakes Sunday. Weak frontal forcing and lack of upper support with the parent shortwave/PV residing over the northern Great Lakes looks to limit precip chances locally with northern areas having the best shot at seeing rain. Near zonal northern jet is then progged to set up for the early week period allowing a series of shortwaves to track into the central Great Lakes maintaining our more active recent pattern. && .MARINE... Low pressure lingers over the Ohio Valley today supporting continued shower chances over Lake Erie, at least for the first half of the day. Modest gradient and sunnier skies in the north promote better mixing supporting an uptick in northeast flow into the Thumb nearshore waters this afternoon. This is especially true for the Saginaw Bay as favorable wind direction funneling down the bay is expected to support gusts between 25-30kts. Small Craft Advisories are in effect today for the all the Bay as a result as well as the Port Sanilac-Port Huron nearshore zone due to higher wave action. High pressure then briefing slides across the region Thursday bringing favorable marine conditions. Active pattern with showers and perhaps a couple thunderstorms return Thursday night into Friday as weakening low pressure lifts in the upper Midwest. && .PREV DISCUSSION... Issued at 1153 PM EDT Tue May 14 2024 AVIATION... Mid/upper clouds will persist across the area around low pressure circulation to the southwest. A lobe of this low will pivot closer to the region overnight with cigs 4-6kft thickening into I-94 and possibly KPTK. There is some chance of MVFR cigs. Lower VFR cigs will be erode/pivot away from area by midday Wednesday, and expect gradual clearing from north to south into the end of the forecast. Northeast winds will prevail throughout the forecast. For DTW/D21 Convection...Thunderstorms are not expected during this forecast period. DTW THRESHOLD PROBABILITIES... * Low confidence in cigs aob 5000 feet late tonight into Wednesday morning. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory from 8 AM this morning to 8 PM EDT this evening for LHZ421-422. Small Craft Advisory from 4 PM this afternoon to 11 PM EDT this evening for LHZ443. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...KDK MARINE.......KDK AVIATION.....DG You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.