Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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744 FXUS63 KGRR 040556 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 156 AM EDT Sat May 4 2024 .KEY MESSAGES... - Increasing Chance for Showers/Storms Later Saturday into Saturday night - Dry end of the weekend - Many chances for rain next week && .UPDATE... Issued at 1101 PM EDT Fri May 3 2024 Nighttime microphysics imagery shows low clouds beginning to fill in across Southeast Lower Michigan this evening. Observations confirm the low clouds with bases below 1,000 feet at several sites. This stratus should expand and roll into Southwest Lower Michigan from the east overnight as easterly winds advect the clouds in. So, quite a bit of the area will be mostly cloudy at daybreak. Some fog is expected as well, especially near and north of I-96. Visibilities below 1 mile are expected. Maximum extent of the stratus and fog should be around 700am. We expect clearing to take place by midday. && .DISCUSSION... Issued at 231 PM EDT Fri May 3 2024 - Increasing Chance for Showers/Storms Later Saturday into Saturday night Southerly winds ahead of an approaching cold front will draw up moisture from the south Saturday into Saturday night. Instability increases as well later Saturday afternoon into Saturday night, but overall remains weak. Aloft some upper level divergence is seen Saturday night over the CWA so that may enhance the lift. Thus the combination of moisture, lift and instability will likely lead to showers and a few storms. Ensemble QPF values, while low, have been trending up with the precipitation for this period. - Dry end of the weekend High pressure over the upper Mississippi Valley will produce plenty of sunshine Sunday. Highs will climb to a couple of degree either side of 70. - Many chances for rain next week The persistent upper trough over the western US is progd to cut off over the northern High Plains during the middle of the week. The result will be several short waves that move in our direction and bring chances for showers and storms. Tuesday night through Wednesday night will be a time frame that will see increased chances for precipitation. An occluded front will lift north toward Lower MI Tuesday afternoon and this will produce some showers/storms. Present indications are that the strongest instability will remain south of the state. However, that could changed this far out. SPC has already highlighted areas to the southwest of the state for the potential of severe storms. Another chance of showers/storms will come Thursday and Thursday night, when the surface low over the northern Plains moves east. Accompanying short waves and a feed of moisture rich air from the south will spur convective development during this time. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 156 AM EDT Sat May 4 2024 Areas of IFR/LIFR cigs and vsbys expected through mid morning Saturday due to fog and low stratus patches drifting westward from the east side of the state. Conditions turning VFR again by Saturday afternoon with a scattered to broken cumulus deck lifting to around 4500 ft. An isolated shower or tstm cannot be ruled out inland from Lk MI in the late afternoon but the potential (and the coverage) looks too low to include in the TAFs. The primary risk of showers and storms holds off until after 06Z Sunday with perhaps the exception of MKG which may see that threat materialize by 04Z. && .MARINE... Issued at 231 PM EDT Fri May 3 2024 Southerly flow will be on the increase Saturday into Saturday night as a front moves in from the west. This will be warm air advection and overall the values are expected to remain under 20 knots. Thus we don`t plan on needing headlines a this time. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ UPDATE...Duke DISCUSSION...MJS/04 AVIATION...Meade MARINE...MJS