Sunrise 6:15 AM   Sunset 9:06 PM Moonrise 4:22 PM   Moonset 3:20 AM

  Print   HELP   Reset   Save   Recall  New

LMZ845 South Haven To Holland Mi- 1105 Am Edt Sun May 19 2024
Rest of today - Northwest winds 10 to 15 knots. Sunny. Waves 1 to 3 feet. Tonight - North winds 5 to 10 knots veering southeast after midnight. Partly cloudy. Waves 1 to 2 feet. Monday - South winds 10 to 15 knots. Mostly Sunny with a chance of rain showers and a slight chance of Thunderstorms. Waves 1 to 2 feet. Monday night - South winds 10 to 15 knots. Rain showers likely and a chance of Thunderstorms. Waves around 1 foot. Tuesday - South winds 10 to 15 knots. Partly Sunny with a chance of showers and Thunderstorms. Waves around 1 foot. Wednesday - Southwest winds to 30 knots decreasing to 15 to 20 knots late in the day. Mostly Sunny with a chance of rain showers. Waves 4 to 6 feet. Thursday - West winds 15 to 20 knots. Sunny. Waves 2 to 4 feet.

LMZ800
No data

FXUS63 KGRR 191649 AFDGRR

Area Forecast Discussion National Weather Service Grand Rapids MI 1249 PM EDT Sun May 19 2024

KEY MESSAGES

- Very warm and mainly dry today

- Continued warm and more humid with scattered storms Monday

- Stormy Monday night through Wednesday

- Hot Tuesday, then cooler

DISCUSSION
Issued at 330 AM EDT Sun May 19 2024

- Very warm and mainly dry today

It will be very warm again today with high temps reaching the low to mid 80s. The exception to this will be near the Lake MI shoreline where winds becoming onshore will keep it cooler. A weak cold front will bring isolated showers early this morning nw of KGRR.

Dry wx is expected for the majority of our area today. However a few showers and storms will redevelop along and just ahead of the weak cold front this aftn over our se fcst area where sb cape values will potentially reach around 2k j/kg as suggested by the 00Z HRRR.

Svr wx is not expected given weak sfc convergence/forcing from the front and weak shear. However an isolated stronger pulse type storm in the vicinity of KJXN seems possible by late aftn coincident with peak diurnal heating and instability. This notion is supported by a consensus of 00Z HRRR convective parameters.

- Continued warm and more humid with some showers/storms Monday

It will become increasingly warm and noticeably more humid Monday as winds become south to southwesterly and waa/moisture advection occurs. SB cape values will build through the day and reach around 1k-2k j/kg. Some stronger to marginally severe convective development is expected in the afternoon and evening in an increasingly humid and unstable airmass with deep ssw flow and as the llj ramps up to around 35 kts late in the day.

- Stormy Monday night through Wednesday

Several rounds of showers and thunderstorms are expected through mid week. The first round arrives Monday night when a short wave tracks across northern Lower. There will likely be storms ongoing Monday evening north of the cwa. However, convection earlier in the day may leave some unattended boundaries that may interact with convection that could fire along the trailing cold front; NAMNest shows a flareup of convection after midnight Monday night over the central cwa where it may take advantage of MUCAPE around 600-700 j/kg. Shear values less than 20 knots suggest severe storms won't be a player Monday night.

That could change Tuesday. A much stronger storm will emerge from the Plains and push a warm front north through the cwa late in the day. We could see some activity along the warm front Tuesday afternoon when SBCAPE climbs to 2k+ j/kg, but the higher likelihood is Tuesday night and Wednesday along the trailing cold front. Model trends have slowed the advancement of the front and if trends continue, early Wednesday could be a favored time to see storms develop. If that occurs, the southeast cwa would realize the most instability Wednesday morning as the front arrives.

Bulk shear climbs to 45-50kts Wednesday ahead of the front and so given the instability already in place, we could see strong/severe storms develop, especially over the southeast cwa. This bears watching.

Once the front clears later Wednesday, we'll see several days of dry weather at the end of the week.

- Hot Tuesday, then cooler

Highs in the lower to mid 80s are expected Tuesday with temperatures falling into the 70s Wednesday with clouds and precipitation along the frontal boundary. Thursday will be the coolest day with highs from the upper 60s north to lower 70s elsewhere. Highs in the lower to mid 70s are expected next weekend.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/
Issued at 1249 PM EDT Sun May 19 2024

VFR conditions ongoing as few cirrus move overhead this afternoon. A few showers/storms are possible this afternoon and evening mainly for LAN/JXN but confidence in terminal impacts is low enough to preclude any TAF mention. Passing cirrus tonight provide the only sensible weather to the terminals after sunset.
Tomorrow, an increase in moisture will lead to the development of scattered cu in the 3.5-6 kft range and the development of scattered showers mainly near and north of I96. Given scattered coverage have included a PROB30 group after 14z for LAN/MKG/JXN.
West winds of 5-10 knots today become northwest around 5 knots tonight before becoming southerly at 5-10 knots Monday.

MARINE
Issued at 330 AM EDT Sun May 19 2024

Winds and waves will remain well below sca criteria through the rest of the weekend into early next week. Potential for marine fog looks minimal today but may increase again a bit on Monday as a more humid airmass begins to move in. Thunderstorms will pose a hazard to mariners early to midweek.

GRR WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...None.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Grand Rapids/Muskegon, MI,