Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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350 FXUS63 KDTX 020421 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1221 AM EDT Sun Jun 2 2024 .KEY MESSAGES... - Showers continue overnight. Rainfall totals generally range between 0.25" to 0.75". - A warming trend continues today and Monday with highs in the lower 80s expected Monday afternoon. - Unsettled weather returns Tuesday and lasts through mid-week with periods of showers and thunderstorms. && .AVIATION... MVFR to IFR ceilings will spread across the terminals within the next few hours along with brief reductions to MVFR visibility at times as rain showers continue to move across the terminals through the early morning hours. The influx of low level moisture will hold the lower stratus and possibly support some fog/drizzle past sunrise as surface low pressure moves through southeast Michigan. There will be a chance for some isolated to possibly scattered showers in the afternoon, but confidence in any showers affecting an airport is low at this time. Conditions gradually improve into the evening with potential for a return of MVFR/IFR ceilings late tonight. For DTW/D21 Convection...Thunderstorms are not expected through this forecast period. DTW THRESHOLD PROBABILITIES... * Low for thunderstorms tonight. * High for ceilings at or below 5,000 feet through at least this afternoon. && .PREV DISCUSSION... Issued at 313 PM EDT Sat Jun 1 2024 DISCUSSION... A plume of showers extends from the Gulf coast to the upper Midwest this afternoon as a southern stream short wave circulation phases with the larger northern stream/Canadian mid level trough/low. Model analysis fields indicate a broad moisture axis/theta-e ridge extending south to north along and ahead of the associated surface pressure system tapping plentiful Gulf moisture. Model fields match up well with afternoon hourly mesoanalyses that measure 1.5 inch PW reaching up to the Chicago area at forecast issuance. The foundation of moisture transport is responsible for the sizable footprint of showers with localized enhancement in and around the southern stream mid level circulation projected to move across southern Lower Mi tonight. So far, the absence of thunderstorms is a notable aspect of the pattern commensurate with mesoanalysis of sub 6 C/km 700-500 mb lapse rate and surface based CAPE hovering around 500 J/kg. Some recovery of instability is likely south of the Ohio valley this afternoon but remains an issue northward across Lower Mi through the evening. Some elevated/nocturnal recovery is possible across the area late tonight as moisture transport remains strong enough to be a destabilizing factor into Sunday morning. This, along with forcing tied to the mid level circulation, otherwise contribute to widespread showers while keeping a stray rumble of thunder possible. A model trend materializing for Sunday is slower exit timing on the surface pressure system from SE Mi in the afternoon. Hi-res and regional models are latching on to this idea as a source for redevelopment or maintenance of scattered showers, especially during peak heating similar to the response in the MO/IL/IA area today. Larger scale forcing does increasingly become an opposing factor mainly in terms of mid level subsidence in the downstream vicinity of the short wave ridge. Opted to hold on to a low end chance POP toward the eastern border region, very dependent on daytime heating, considering upstream observations today. The influence of the inbound mid level ridge and surface high pressure gain traction Sunday night for dry weather Sunday night and Monday. Mixed high clouds are the dominant sky cover Monday which allows afternoon temperatures a chance to reach the lower 80s under the broader long wave ridge to zonal flow transition. Today`s models then show a reasonable consensus on continuing a pattern change toward mid week. Pacific upper jet energy digging into the west coast initiates Plains height falls Tuesday into an impressive affecting the Great Lakes by Wednesday. MARINE... A slow moving low pressure system will move across southern Lake Michigan this evening, then will advance toward southern Lake Huron on Sunday before weakening. This system will drive an area of rain across the lakes tonight through Sunday morning. As the low pressure system weakens, high pressure will develop across the region Sunday night into Monday. Winds will generally remain light given the weak gradient across the eastern lakes. An approaching warm front will bring a chance of showers and thunderstorms to the region on Tuesday. Southeast wind gusts approaching 20 knots are possible as the gradient increases ahead of this front. The warm front will then be followed by a strong cold front on Wednesday, sustaining the chances for thunderstorms. HYDROLOGY... Showers and a stray thunderstorm in the Midwest and Ohio valley today are on schedule to move across Lower Michigan tonight and Sunday. The activity is fueled by Gulf moisture feeding into low pressure and a weakening front moving across the region. Rainfall amounts between 0.25" to 0.75" are expected, although localized higher amounts around 1 inch are not out of the question. Brief and minor flooding of prone urban and low-lying areas, ponding of water on roadways, and rises in area rivers are possible in this scenario until the pattern becomes scattered and exits eastward Sunday afternoon. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....AA DISCUSSION...BT MARINE.......SC HYDROLOGY....BT You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.