Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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281 FXUS63 KGRR 291450 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1050 AM EDT Mon Apr 29 2024 .KEY MESSAGES... - More Showers and Storms Today - Main chance for rain in the Wed-Sun time frame is Thurs Night-Fri - Temperatures remain on the warm side of normal this week && .UPDATE... Issued at 1043 AM EDT Mon Apr 29 2024 We updated to marine forecast to add fog for today. Webcams and high res model visibility forecasts support a risk for fog out on the lake. The risk for some severe weather this afternoon is not zero. We have a warm front around and decent deep layer effective shear. High res models generally show one round of convection early this afternoon and another later this afternoon. We will be monitoring trends closely. Overall they are supporting the most vigorous convection on the east side of the state. We will continue to monitor trends closely. && .DISCUSSION... Issued at 343 AM EDT Mon Apr 29 2024 - More Showers and Storms Today Surface analysis as of 2am shows a surface low centered over eastern IA with a warm front draped across southern WI into the I-96 corridor in southern MI. A few warm frontal rain showers have initiated just north of the surface boundary, but otherwise most areas across the CWA remain dry this morning. Surface based instability diminished shortly after sunset yesterday evening, so mainly rain is expected with any showers. As the low slides northeastward into eastern MN / western WI, the warm front will lift northwards and a steadier batch of showers currently moving through central IL will enter southern MI. More widespread showers can be expected during the mid to late morning hours. A few storms will be possible across the eastern CWA during the afternoon as a cold front moves through, but there`s still a question on storm strength. Instability looks limited with MLCAPE under 1000 J/kg, but bulk shear will be supportive (40 to 50 knots) alongside an elevated 850mb jet to 30 to 40 knots. Currently thinking non-severe given the expected afternoon cloud cover, but if any breaks occur we could see some decently strong storms develop across the eastern CWA. The front works its way east by this evening with dry weather to start Tuesday. Surface ridging moves in place Tuesday leading to the return of dry weather. Sunny skies are expected with highs in the 60s. - Main chance for rain in the Wed-Sun time frame is Thurs Night-Fri The main chance for showers and storms will come late in the work week from Thursday night into Friday. A strong shortwave will eject out of a Plains trough and move through the Great Lakes region during this time frame. A cold front will sweep through Thursday night and provide the main focus for showers and storms. Most unstable CAPE values are forecast to reach the 1000-2000 j/kg range so there will be solid chances for convection. Otherwise, there is a weak front that approaches and washes out over the area Tuesday night into Wednesday. The chance for precipitation is generally low given the weakening front. - Temperatures remain on the warm side of normal this week Temperatures through the forecast period are expected to remain near to above normal. Highs will generally be in the middle 60s to lower 70s. Normal highs are in the lower to middle 60s for this time of year. Given fruit trees and flowers are in or moving too full bloom it is good we are not looking at cold weather in the short term. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 750 AM EDT Mon Apr 29 2024 A warm remains to be situated just south of the Interstate 96 corridor this morning which has allowed LIFR and VLIFR conditions to remain in place at places like GRR and LAN. Further south VFR conditions are occurring south of the warm front along I-94. We expect the warm front to nudge northward this morning and all areas should trend to VFR as we head into and through the afternoon. An area of rain showers continues to work northward across Lake Michigan from portions of IL/IN. This shower activity should press into at least the western TAF sites of AZO, GRR and MKG this morning. Scattered rain showers are expected this afternoon as a cold front presses in from the west. VFR weather is expected tonight as the front sweeps east. Gusty southwest winds of 15-25 knots are expected this afternoon ahead of the front. && .MARINE... Issued at 343 AM EDT Mon Apr 29 2024 Winds and waves increase slightly this afternoon, though conditions should stay below Small Craft Advisory thresholds. Waves to 2 to 3 feet are expected this afternoon with southerly winds at around 15 knots gusting to 20 knots. Dewpoints will still be elevated enough for some fog formation, but winds should be high enough to prevent any dense fog from developing. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...MJS/Hoving DISCUSSION...Duke/Thielke AVIATION...Duke MARINE...Thielke