Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, 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
48
49
009 FXUS63 KGRR 180540 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 140 AM EDT Wed Sep 18 2024 .KEY MESSAGES... - Dry and warm weather continues - Slight chances for rain late this week into next week && .DISCUSSION... Issued at 328 PM EDT Tue Sep 17 2024 Short term: Persistence forecast the way to go in continued stagnant pattern with light winds and mainly clear skies. Cool overnight lows in the upr 40s to mid 50s and patchy ground fog followed by warm/dry daytime conditions with highs in the lower to mid 80s. Guidance is showing higher sfc dew pts arriving from the east on Wednesday which could support a cumulus field, but suspect daytime mixing will just lower sfc dew pts again in the afternoon. Fine viewing conditions tonight for the 1044 PM partial eclipse of the full harvest moon. Longer term: High pressure will continue to dominate the weather pattern through the work week. This high will allow for maximum temperatures to remain in the 80s through the week with a dry forecast through most of Friday. There continues to be a signal through the mid range models with all the deterministic models showing a persistent 500 mb short wave moving through the upper midwest Friday into Saturday. This negatively tilted trough should be pulling in mid level moisture that across the lakes could be enough to bring some moisture into the western half of lower Michigan. There remains some questions whether or not there will be enough moisture to overcome the dry air that has been entrenched over Michigan this past week. The cold front associated with that trough will lower temperatures into the 70s into the weekend, the slightly anomalous moisture might not be enough to create precipitation. The ridge will continue to be weathered down with a larger, deeper upper level low will move from the southwest into the central plains. There remains a bit of discrepancy on the timing of that low, but as the low from the southwest moves eastward, another short wave will be moving along the Canadian border and into the midwest. Convergence between these two system will bring a better chance of precipitation Sunday into Monday. As stated previously, there remains some strength and timing but the next best chance for rain are Sunday into Monday. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 140 AM EDT Wed Sep 18 2024 Consensus of short term guidance continues to indicate the potential for MVFR to IFR visibility with mist and patchy fog mainly between 10 and 12 Z. Air fields closer to Lake Michigan, such as MKG, have lesser potential. A few AWOS are already dipping into MVFR visibility. Fog and scattered low clouds should mix away with drier air aloft within a couple hours after sunrise, then there is high confidence in VFR for the remainder of the day. && .MARINE... Issued at 328 PM EDT Tue Sep 17 2024 Very tranquil conditions for mid Sept continuing on Lk MI with winds generally only 5-10 kts and waves a foot or less. Expect onshore lake breezes developing in the afternoon and offshore breezes occurring at night. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Meade/Ceru AVIATION...CAS MARINE...Meade