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
50
995 FXUS63 KGRR 281402 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1002 AM EDT Sun Apr 28 2024 .KEY MESSAGES... - Showers and Storms Continue into Sunday and Monday - Multiple chances for rain exist from Monday night and beyond - Near to above normal temperatures continue this week && .UPDATE... Issued at 1001 AM EDT Sun Apr 28 2024 The POPs/Weather grids have been updated per the latest radar trends and HRRR forecast. Steadier rain will lift north this morning but the wavering surface front will remain across the central forecast area as it has been reinforced by outflow from this mornings showers. Partial clearing this afternoon across the southern half of the forecast area could create enough sfc-based instability to pop some storms, as indicated by the HRRR during the late afternoon. This would most likely occur along the residual outflow boundary/sfc front across the central forecast area in the general vicinity of GRR to LAN. && .DISCUSSION... Issued at 356 AM EDT Sun Apr 28 2024 - Showers and Storms Continue into Sunday and Monday A surface low ejecting out of the southern plains will carry a warm frontal boundary into lower Michigan today. This front will stall over central lower this afternoon keeping showers mainly north of I- 96. Though the bulk of the instability will be mainly south of the frontal boundary and convection, storms will be possible. Severe weather does not look likely. HREF probability matched mean values continue to advertise local patches of 1 to 1.5 inches of rain from now to Monday morning, suggesting some training of storms may be possible. The upper trough associated with the surface low to our west moves into Ontario providing better upper support for an approaching cold front. Widespread showers encompass the CWA Sunday night and Monday. Storms will be possible as modest instability ahead of the front builds with bulk shear values up to 35 to 45 knots. Showers exit east late Monday leading to a dry Tuesday. - Multiple chances for rain exist from Monday night and beyond The upper system responsible for our chances for rain this weekend exits the Great Lakes into Canada Monday night. The rain will end Monday evening and we will be dry the remainder of the night and through Tuesday. A vort lobe pivots through the Great Lakes Tuesday night into Wednesday morning with another chance for rain. This chance for rain appears to be quite light as the upper system is located well west of the area. Another active weather period looks to be Thursday into Saturday as an upper trough moves into and through the area. Showers and thunderstorms are both in the forecast during this time frame as surface dew points surge into the 60s F. Most unstable CAPE values reach the 1000-2000 j/kg range on Thursday which could be the most active weather day of the upcoming work week. Bottom line the 7 day forecast remains active and wet with WPC QPF values through next Sunday morning on the order of 1.00 to 2.00 inches. - Near to above normal temperatures continue this week Normal highs are in the lower 60s this time of year and we are forecast to be above that through the the 7 day forecast. The warmest day of the period will be Thursday where we could hit 80 along I-94. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 750 AM EDT Sun Apr 28 2024 A warm front will be situated across the area today. Lower clouds (MVFR) will be in place much of the next 24 hours at the I-96 TAF sites closer to the front. Some IFR will even occur this morning. The I-94 TAF sites will improve as we head into the afternoon to VFR. Periods of showers and storms will occur over the next 24 hours with the most confident batch of showers/storms being this morning. Another round is possible this afternoon, but it is a lesser confidence event. && .MARINE... Issued at 356 AM EDT Sun Apr 28 2024 A moist airmass remains in place today and Monday with dewpoint values into the mid to upper 50s. This moist air over cold water will produce dense fog along the lakeshore, therefore a Marine Dense Fog Advisory is in effect. Meanwhile, winds and waves should stay low through today and much of Monday. A cold front will approach the area late Sunday into Monday and may bring hazardous wind gusts as well as showers and storms. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Dense Fog Advisory until 8 PM EDT this evening for LMZ844>847. && $$ UPDATE...Ostuno DISCUSSION...Duke/Thielke AVIATION...Duke MARINE...Thielke