Sunrise 6:37 AM   Sunset 8:45 PM Moonrise 1:50 AM   Moonset 10:39 AM

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LMZ845 South Haven To Holland Mi- 405 Pm Edt Tue Apr 30 2024
.small craft advisory in effect from late tonight through Wednesday afternoon - .
Through early evening - South winds 5 to 10 knots. Sunny. Waves around 1 foot. Tonight - Southeast winds around 10 knots increasing to 10 to 15 knots late at night, then veering south 15 to 20 knots toward daybreak. Partly cloudy in the evening, then mostly cloudy with a slight chance of rain showers overnight. Waves 1 foot or less building to 2 to 3 feet toward daybreak. Wednesday - Southwest winds 15 to 25 knots decreasing to 10 to 15 knots late in the day. Mostly Sunny. Waves 2 to 4 feet.Wednesday night - Southwest winds 5 to 10 knots veering northeast late at night, then veering east toward daybreak. Partly cloudy with a slight chance of rain showers. Waves 1 to 2 feet. Thursday - East winds 10 to 15 knots veering southeast late in the day. Partly Sunny with a chance of rain showers. Waves around 1 foot. Thursday night - Southeast winds 15 to 20 knots. Rain showers likely. Waves 1 to 2 feet. Friday - South winds around 15 knots veering northwest late in the day. Rain showers likely. Waves 1 to 2 feet. Saturday - East winds around 10 knots backing northwest. Mostly Sunny. Waves 1 foot or less. Sunday - Northwest winds around 15 knots. Mostly Sunny. Waves 1 to 2 feet.

LMZ800
No data

FXUS63 KGRR 301937 AFDGRR

Area Forecast Discussion National Weather Service Grand Rapids MI 337 PM EDT Tue Apr 30 2024

KEY MESSAGES

- Gusty winds and a shower risk later tonight into Wednesday morning

- Warmer than normal temperatures ahead

- Several Chances for showers and storms ahead

DISCUSSION
Issued at 255 PM EDT Tue Apr 30 2024

- Gusty winds and a shower risk later tonight into Wednesday morning

A 40 knot low level jet moves into the region late tonight into Wednesday morning. This feature advects in a moist air mass with PWAT values progged to reach around an inch based off of the ensemble guidance. Given the moisture and lift, some shower activity is expected to track in from the west as this the low level jet arrives. If the upstream convection that develops this evening diminishes slower than expected, a few thunderstorms could make it across the lake, mainly around daybreak. SPC HRRR MU CAPE values is still struggling to show much if any instability so we will keep the precipitation as showers for now. Any heavier downpour could lead to gusty winds. A better shot for gusty winds will be as mixing develops Wednesday morning. Base on projected heights and the winds at those levels, we should see gusts topping 30 mph at times.

- Warmer than normal temperatures ahead

Overall zonal flow will continue through the rest of the week and into next week. The positive height anomalies favor continued warm air advection through this period. Latest Ensembles and anomalies continue to show a prolonged period of +1 or greater anomalous warmth into next week. That should keep daytime highs 5 to 10 degrees above normal. This correlates to Highs in the 70s through the weekend.

- Several Chances for showers and storms ahead

A strong frontal boundary in between a retreating high and a large upper level low moving along the Canada border should provide enough moisture and instability for showers and storms late Thursday night into Friday morning. The bulk of the cold air associated with that system should remain north. There is a strong short wave associated with that system and given the current gradient there should be some mid to low level winds should provide enough shear for convection.
Latest mid range models continues to downplay the moisture associated with it through there remains PWATS of an inch to 1.25 inches.

Another opportunity for precipitation will come in the form of a tertiary trough on the back side of the above mentioned upper level low. As that low exits to the northeast it will swing an elongating trough through the Great Lakes. Behind that trough is some cold air that though above freezing, current 850 mb temps have it +2 to +3C which is should allow for a decent cold frontal boundary that could aid convection. So isolated storms are possible at this point, however it is a ways ahead so confidence is low.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
Issued at 139 PM EDT Tue Apr 30 2024

VFR conditions will dominate for the most if not all the forecast period. Expect the winds to slacken this evening and then increase and mix out early Wednesday morning. A front will bring gusty winds beginning around 09Z with a strong LLJ which will cause Low level wind shear 2KFT and below until around 13 to 14Z. The timing for this shear is reflected in the TAFs. As the LLJ exits expect lower cigs, after 15Z.

MARINE
Issued at 255 PM EDT Tue Apr 30 2024

A low level jet will be moving into the nearshore zones overnight and Wednesday morning. This feature will support increasing winds and building waves. The flow will initially be south southeast later tonight but it will veer to the southwest during the morning. We will issue a small craft advisory for most marine zones as a result.



GRR WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...Small Craft Advisory from 5 AM to 4 PM EDT Wednesday for LMZ845>849.

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