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
500 FXUS63 KDTX 140709 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 309 AM EDT Wed Aug 14 2024 .KEY MESSAGES... * Stretch of dry and seasonable weather conditions expected today as daytime highs approach the mid 80s. * Increasing cloud cover and shower potential arrives Thursday evening and lingers through the weekend. * Chance of thunderstorms Friday and Friday night. && .DISCUSSION... An upper level ridge (582-585 DAM at 500 MB) will be building into the Central Great Lakes through tonight. Any shallow radiation fog this morning will burn off quickly, and with 850 MB temps of 14 to 15 C advertised, highs in the 80 to 85 degree range can be expected. Dry mid levels and little to no cape should result in dry day. But with the weak surface flow and lake breeze interaction there is technically a non-zero chance a weak shower/sprinkle could develop. A slow evolving pattern then kicks in for the end of the work week into the weekend as the copious amount of upper level energy/PV over the Pacific Northwest/northern Rockies leads to a closed 500 MB low tracking through the Great Lakes region. This system does look to tap into some good moisture over the Southern Plains/Gulf of Mexico, with the moisture plume/850-700 MB Theta-e Ridge arriving Thursday Night, but the deeper moisture (PW values 2+ inches) looks to be south of the border and then tracking east. Regardless, plenty of forcing/ascent Thursday night and Friday to support showers and possible thunderstorms. Wrap around moisture and surface low slowly moving through Lower Michigan on Saturday will also lead to additional numerous-widespread showers, likely lingering into Sunday. 00z Euro ensembles showing a wide range of QPF outcomes for this Thursday night-Sunday time frame, but appears like we should see total amounts at least around 1 inch, with substantial amount of members indicating 2+ inches. && .MARINE... Area of high pressure holds over the region for one last day today maintaining light winds and dry conditions. Pattern change occurs Thursday as upper Midwestern low pressure reaches the Great Lakes resulting in strengthening southeast winds in advance. Peak gusts looking to occur late Thursday night into Friday with gusts between 20-25kts. Low pressure slowly tracks over the central Great Lakes Friday through Sunday supporting periods of showers and storms across the area. With the cooler accompanying airmass and upper trough overhead, there will be a chance for waterspouts with this system. Modest (10-20kt) winds shift to north-northwest by late Saturday on the back side of the low before eventually weakening Monday with the departure of low pressure. && .PREV DISCUSSION... Issued at 1200 AM EDT Wed Aug 14 2024 AVIATION... Favorable radiative cooling conditions with evapotranspiration will bring the potential of light br/hz at daybreak Wednesday. Surface high pressure and daytime heating will allow for persistence boundary layer cumulus by midday. For DTW/D21 Convection...No thunderstorms will occur through the TAF period. DTW THRESHOLD PROBABILITIES... * None. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...SF MARINE.......KDK AVIATION.....CB You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.