![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
748 FXUS63 KDTX 061903 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 303 PM EDT Sat Jul 6 2024 .KEY MESSAGES... - Isolated to widely scattered showers will be possible this afternoon and evening, generally north of I-94. Some rumbles of thunder cannot be ruled out. - The holiday weekend closes out with dry weather Sunday under partly sunny sky. - Hot Monday with highs in the upper 80s. Shower and thunderstorm chances return Monday and Tuesday. && .DISCUSSION... A cold front has cleared the state as of early this morning, and outside of spotty showers over central Michigan, most locations are dry in the wake of the front with temperatures presently in the mid- 60s. Residual moisture and humidity will hold on today across SE MI, which will aid in the production of isolated to widely scattered shower activity. The inherited forecast looks reasonable, holding PoP chances generally north of I-94, with highest PoP chances (30- 35%) located along and north of I-69, tied to the greater moisture and subsequently better instability. Instability and bulk shear are not favorable for sustainable activity today, holding at 500 J/kg and around 15-20 knots respectively. Additionally, a cap just under h600 will limit convective depth and coverage. However, steep low level lapse rates with the passage of multiple upper-level waves do justify the PoP potential. Cannot rule out some embedded thunderstorms, but LI values of 0 to 1 and very poor mid-level lapse rates favor rain showers. Shower and storm potential will wane with the loss of daytime heating, with lingering potential lasting through 10PM- Midnight. Highs hold in the upper 70s in the wake of the front. A weak shortwave ridge will fill in behind the departing shortwave and will bring a day of dry weather with temperatures returning into the mid 80s for a high. The return of warmer weather is a result of multiple upper-level waves that fill in over the Plains with trough amplification taking place across the greater Plains through the early week period. Initially, this directs heat and moisture from central US downstream into the Great Lakes noted by h850 temperatures increasing from 16C Sunday evening to 18C by Monday evening. This brings daytime highs in the upper 80s, possibly reaching 90 across urban areas on Monday. Rain and thunderstorm chances are also possible Monday with the improved moisture and support from glancing shortwaves ahead of the main trough axis. The better chances for numerous to widespread showers with embedded thunderstorms will enter late Monday into Tuesday tied to the better connection with the trough, with the axis swinging over Michigan late Tuesday night. Medium range models are more muddled through the midweek period given subtleties with shortwave passages and interactions. One major consideration that models will struggle with this far out will be the upstream impacts of Tropical Storm Beryl. The latest ECMWF is much less progressive relative to the 12Z model run and pushes the system into the Ohio Valley, clipping portions of SE MI. Even less progressive is the ICON (and ICON-EPS), which pushes the center of the low right over Michigan. Regardless, not much credence is given into any one particular model solution at this time factoring in limited sampling from the upper-air network, but it is worth noting as several deterministic runs display a much less progressive solution for the 00 cycle. Closer attention will be given to the path of the system as it makes landfall somewhere over southeast TX by early Monday. && .MARINE... Light winds and low waves accompany the weak pressure gradient in place through this weekend. Apart from a stray shower this afternoon or early evening, dry conditions will prevail through Sunday as an area of weak high pressure builds in over the Ohio Valley. Southerly wind of around 10 knots then develops on Monday ahead of the next frontal system moving in from the Midwest. This system will bring scattered showers and storms late Monday into Tuesday as it tracks through. Slightly cooler northerly flow follows for the mid-week. && .PREV DISCUSSION... Issued at 214 PM EDT Sat Jul 6 2024 AVIATION... Early day stratus lifted and mixed out leaving mostly VFR cu around for the afternoon. Could see a few cigs still dipping to 2500- 3000ft for a bit before finally mixing out for good here in the next hour or two. We then look to this afternoon into the evening hours where the trough draped across Mid MI tries to initiate showers and thunderstorms. There have been some very small isolated showers popping up already but all very short lived as the upper levels of the atmosphere are not favorable for longer lived cells. I left any mention of showers/thunderstorms out of the tafs as there isn`t a clear signal for any taf site to make a mention. Best chances appear to be PTK and FNT due to the current activity, when models showing MBS having better chances this evening. We`ll monitor and amend when necessary. Chances of thunderstorms appear low due to short duration of the showers and unfavorable upper levels of the atmosphere. Dewpoints hanging around 60 degrees and any rain that occurs will make fog possible again tonight. For DTW/D21 Convection...Widely scattered showers and a thunderstorm or two will be possible this afternoon/evening, but best chance will hold north of KPTK. DTW THRESHOLD PROBABILITIES... * Low for thunderstorms this afternoon. * Medium for ceilings at or below 5000 ft this afternoon. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...BC MARINE.......TF AVIATION.....DRK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.