Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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006 FXUS63 KGRR 010737 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 337 AM EDT Wed May 1 2024 .KEY MESSAGES... - Lingering showers this morning, then again Thursday - Best Rain Chances are Friday and Next Tuesday - Warm Pattern Persists through Middle of Next Week && .DISCUSSION... Issued at 337 AM EDT Wed May 1 2024 - Lingering showers this morning, then again Thursday There is a broken line of light showers over Lake Michigan as of 07z this morning that is trying to make its way over the area. This rain activity is out ahead of a low level jet that is pushing 50 knots, and bringing a temporary surge of some moisture and warmth aloft. Drier air at the sfc is eating away at the leading edge of the rain. Over the next 2 to 4 hours, the moisture aloft will be low enough and some low level moisture arrives to bring our best chance of rain, which is still not great. After the next 2 to 4 hours, the nose of the low level jet translates east quickly, and we lose moisture aloft quickly. Other than the early morning light showers and clouds, we will see clearing take place by mid-late morning from West to East. Temperatures will not really be affected as the air is not really different behind the system than ahead of it. Highs will be in the 70s. Dry weather will hold on then from this morning through Thursday morning with upper ridging building in and amplifying a bit. Our next threat of rain will be Thursday afternoon. This will be somewhat of a similar setup as this morning as a low level jet to our west noses in here late Thursday. The majority of the rain should stay off to our west through Thursday afternoon as the best convergence at the nose of the low level jet is located out there. We do see a portion of the warm and moist nose clip the area, which will bring a low chance of the rain showers at that time. - Best Rain Chances are Friday and Next Tuesday A shortwave pivoting northeast on the ern periphery of the nrn Plains trough on Thursday night and Friday helps send a warm front then cold front through the region. Pops ramp up late Thursday night in mainly wrn sections as the warm front lifts northward and brings in PWATs around 1.25 and mid 50 dew points although at this time the low level jet looks unfavorable for more widespread convection. On Friday as the sfc cold front drags eastward across the area we see likely pops for showers and storms. The severe wx threat looks low since the best deep layer shear stays to our west and degree of instability is questionable as well. Only small pops are warranted on Saturday and Saturday night as another weakening sfc frontal boundary slips through then it looks like we end up mainly dry for Sunday/Monday as the main baroclinic zone slips south of MI thanks to sfc ridging building in. Our next good chance of showers and storms after Friday comes next Tuesday when the sfc high slips away and the frontal zone comes back north as a warm front. Deep layer shear is progged to be better on Tuesday since the Plains upper trough is positioned a bit farther east by that time, so there could perhaps be some stronger storms. - Warm Pattern Persists through Middle of Next Week Persistent troughing aloft from the northern Rockies to the northern Plains/south-central Canada through the middle of next week keeps positive height anomalies over the Great Lakes Region. The upshot is for several days in a row with highs temperatures in the 70s which is about 10 degrees above normal for early May. Frequently cooler near Lake Michigan however as is always the case this time of year. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 158 AM EDT Wed May 1 2024 A brief period of MVFR cigs is possible through mid morning as a band of weakening rain showers passes through the region. Otherwise VFR weather will prevail the next 24 hours with winds being the primary aviation impact. Initially a period of LLWS can be expected through daybreak as sfc winds increase out of the southeast to 10-15 kts yet winds just above the sfc sfc ramp up considerably out of the southwest to near 40 kts. After 12-13Z deeper mixing behind a sfc cold frontal passage will promote strong gusty west-southwest sfc winds to 30 kts which become west-northwest in the afternoon. Winds diminishing late in the day and especially after sunset. && .MARINE... Issued at 337 AM EDT Wed May 1 2024 We will be able to let the Small Craft Advisory continue as is this morning, and allowing it to expire this afternoon. The core of best winds is moving through right now. Winds will diminish as conditions over the more stable cool waters improve. The next wind event that might necessitate another Small Craft Advisory looks to begin Thursday afternoon and continues through Thursday night ahead of the next system that will approach the area. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 4 PM EDT this afternoon for LMZ845>849. && $$ DISCUSSION...NJJ/Meade AVIATION...Meade MARINE...NJJ