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
825 FXUS63 KDTX 060707 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 307 AM EDT Mon May 6 2024 .KEY MESSAGES... - Dry weather with some high clouds today. - There is a risk for isolated strong to severe storms Tuesday evening southwest of a FLint to Detroit line. - There is another chance for showers on Thursday. && .DISCUSSION... Surface high pressure will become centered over Lake Huron today, tucked under a mid level ridge axis over Lower Mi. Easterly flow circulating around this anticyclone will sustain ample dry air in the low to mid levels today. A short wave impulse over the Mid Mississippi Valley early this morning is however driving an abundance of high level clouds across southern Michigan. Model RH probs indicate these high clouds will remain in place through the afternoon as this short wave feature tracks across the Ohio Valley. These clouds and the easterly sfc winds associated with the high will keep afternoon highs in the 60s, with cooler readings along Lake Huron. The high clouds are expected to exit to the east late this afternoon and evening as the short wave feature weakens as it heads toward the Mid Atlantic. Clearing skies with an expected weakening of the sfc gradient as the high expands across the eastern lakes will support ideal radiational cooling conditions tonight given the dry boundary layer. Nighttime mins will drop into the 40s accordingly. An deep upper low will evolve from a highly amplified long wave trough over western NOAM and is forecast to become centered over the northern high plains by Tuesday. The associated occluded sfc low will have a warm front extending eastward all the way to the Ohio Valley. An intense mid/upper level jet lifting out of the southern plains will take aim on Lower Mi Tuesday afternoon/evening. A ribbon of enhanced isentropic ascent along the nose of the mid level jet is forecast to traverse Se Mi roughly in the 21Z to 00Z time frame late Tuesday. Latest hi res guidance indicates the axis of forcing narrowing as it lifts across southeast Michigan, which may only support a band of scattered to broken showers. Some degree of instability is then forecast to advect into Se Mi during the evening along the sfc warm front. Given the late day timing, sfc based instability may struggle to make inroads too far into the forecast area. Ample elevated instability amidst steepening mid level lapse rates will still support a chance of thunderstorms area wide, with hail being a concern, Given 0-6km bulk shear values of 60-70 knots, a marginal risk for severe storms is in the current day 2 soutwest of a Flint ot Detroit line, which has the better potential to see some late day surface based instability. Mid level dry air will expand across Se Mi by Wednesday. Model soundings indicate respectable mixing depths by afternoon, which will warrant warm afternoon highs from the mid 70s to near 80. Ensemble spread increases markedly with respect to timing/amplitude of short wave energy forecast to lift out of the central high plains and across the Ohio Valley/southern lakes region Wednesday night/Thursday. The latest 00Z model suite is at least supportive of a chance of rain and continue to hold the better instability south of the state. && .MARINE... High pressure built over the region overnight and will hold into Tuesday. During this time, variable winds under the high will generally hold under 15 knots with low wave heights. Next chance of showers and thunderstorms comes Tuesday afternoon through Tuesday night as a warm front gets pulled up through the Great Lakes. Winds will become easterly Tuesday with gusts 15 to 20 knots. After a possible lull in precipitation on Wednesday, a low pressure system will then target the area on Thursday bringing another chance for showers and thunderstorms. At this time winds and waves are likely to remain below marine headline criteria through the forecast. && .PREV DISCUSSION... Issued at 1157 PM EDT Sun May 5 2024 AVIATION... High pressure settling across the northern Great Lakes supplies SE Mi with cool and dry air late tonight through Monday evening. This eliminates concern for low level clouds while a generous supply of cirrus spreads in from the TN valley low pressure system. High pressure becoming centered over northern Lake Huron sets up a steady east wind across the region by mid morning. Lake breeze augmentation leans wind direction toward the NE at MBS and SE at DTW by mid afternoon into Monday evening. For DTW/D21 Convection... thunderstorms are not expected late tonight through Monday evening. DTW THRESHOLD PROBABILITIES... * None. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...SC MARINE.......DRK AVIATION.....BT You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.