Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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573 FXUS63 KDTX 020758 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 358 AM EDT Tue Jul 2 2024 .KEY MESSAGES... - Seasonable conditions today as clouds thicken through the day. - Potential for showers to develop tonight, mainly across the Saginaw valley and thumb region. An isolated non-severe thunderstorm also possible. - Chance of showers and thunderstorms will continue into Wednesday as conditions turn more humid. An isolated strong to severe storm will be possible during the afternoon, capable of producing strong wind gusts. - Typical heat and humidity for the 4th of July holiday. && .DISCUSSION... Low and mid level ridging entrenched locally early this morning. This pattern effectively solidifying a profile characterized by a rising thickness field, dry ambient environment particularly below 700mb and a high degree of stability captured through a deep layer. Upstream satellite trends lend support for a steady increase in mid level cloud with time today, as mid level southwest flow yields better moisture transport above 700 mb. Some hints within recent model guidance for some sprinkles or very brief light showers to materialize late today as this advective process gets a boost from shortwave energy, possibly convective induced, lifting toward northern lower. Very low confidence that any activity actually leads to a measurable amount of rain, so tentatively plan to hold with a mainly dry forecast. General moderation of the thermal profile despite the inbound cloud nets a return to seasonable temperatures today. Highs around 80 degrees. Low amplitude mid level wave shearing through the mean southwest flow will track into the northern great lakes overnight into Wednesday. Steering flow generally ensures greater precipitation potential tied to the main area of dcva/height falls remain northwest of the area through the night, with some potential mainly across the Saginaw valley. Trailing cold front arrives Wednesday. Frontal convergence remains weak as the boundary becomes parallel to the mean flow, but interaction with a moistening boundary layer condition provides a window for convective development. Higher precip chance with eastward extent, with overall pace of the front relative to daytime destabilization dictating whether a more organized convective episode can manifest locally or remain to the east/southeast. Targeted conditional marginal risk offered by the SPC Day 2 outlook for the eastern zones highlights the isolated stronger wind gust potential in this environment. Drying conditions within veering low level post-frontal flow from northwest to southeast late in the day. A seasonably warm/moist and unstable thermodynamic profile maintains residence for the 4th of July holiday. Model consensus offers a high temp forecast of mid 80s. Maintenance of an energetic lower amplitude southwest flow complicates the precipitation forecast this period, as there remains some potential for a still ill-defined wave to engage this profile favorably during the peak heating cycle. Forecast outlines a more conservative/drier stance overall at this stage, simply offering a lower end mention focused across southern sections. An upward revision remains possible should a more definitive signal emerge. A much better convective signal exists for the Friday period, anchored by the arrival of organized forced ascent associated with a deeper mid level wave/low. Typical summertime conditions then expected for the upcoming weekend, with temperatures near or just above average and some shower/t-storm potential within broad mid level troughing. && .MARINE... A high pressure system will depart into the continental northeast today while a low pressure system arrives into Lake Michigan late tonight into early tomorrow morning. This will veer wind direction from the southeast to the southwest. Wind speeds and gust potential will increase slightly with the departure of high pressure, with gusts increasing to around 20 to 25 knots across Lake Huron. A cold front is then expected to move over the Great Lakes tomorrow, which will bring increasing chances for showers and thunderstorms both ahead and along the front. The southwest fetch across the Saginaw Bay will also bring a window to see gusts around 25 knots tomorrow afternoon and evening. Small Craft Advisories for the bay may be needed. A weak area of high pressure will then build in Thursday, relaxing wind speeds and decreasing gust potential. && .PREV DISCUSSION... Issued at 334 AM EDT Tue Jul 2 2024 AVIATION... High pressure will continue to provide VFR conditions as it shifts off to the east overnight into Tuesday. As this occurs, mid to upper level moisture will increase aoa 15kft. Light east/southeast winds tonight will become more south-southeast on Tuesday with wind speeds peaking around 10 knots (a bit stronger for MBS?) by midday. For DTW/D21 Convection...Thunderstorms are not expected during the upcoming forecast. DTW THRESHOLD PROBABILITIES... * None. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...MR MARINE.......AM AVIATION.....MR You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.