Sunrise 5:51 AM   Sunset 7:52 PM Moonrise 10:10 PM   Moonset 6:24 AM

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LMZ543 Expires:202404251300;;338548 Fzus53 Kgrb 250842 Nshgrb
nearshore marine forecast national weather service green bay wi 341 am cdt Thu apr 25 2024
for waters within five nautical miles of the shore on lake michigan
lmz542-543-251300- sturgeon bay to two rivers wi-two rivers to sheboygan wi- 341 am cdt Thu apr 25 2024
Early in the morning - SE wind around 5 kts. Clear. Waves 2 ft or less. Today - S wind 10 to 15 kts. Sunny. Waves 2 ft or less. Tonight - SE wind 10 to 15 kts. Clear. Waves 2 ft or less building to 2 to 4 ft early in the morning. Friday - SE wind 10 to 20 kts with gusts to around 25 kts. A chance of rain showers in the afternoon. Waves 3 to 5 ft. A small craft advisory may be needed. Friday night - SE wind 15 to 25 kts with gusts to around 30 kts. Rain showers and a chance of Thunderstorms. Waves 3 to 5 ft building to 5 to 8 ft.

LMZ500
No data

FXUS63 KGRB 250836 AFDGRB

Area Forecast Discussion National Weather Service Green Bay WI 336 AM CDT Thu Apr 25 2024

Forecast discussion for routine morning forecast issuance

KEY MESSAGES

- Elevated fire weather conditions are likely today due to relative humidities ranging from 20 to 30 percent. However, relatively light winds and seasonal temperatures will keep conditions from meeting critical fire weather thresholds.
Humidity readings as low as 30 percent are possible on Friday along the Upper Michigan border, combined with increasing southeasterly winds with gusts around 25 mph.

- Two systems will result in rounds of showers and thunderstorms from Friday afternoon through Sunday night. There is an increasing risk of strong or severe storms on Saturday, especially during the afternoon and evening. Large hail and damaging winds are the main risk. Storms this weekend could also produce locally heavy rain with isolated flash flooding possible.

- Conditions hazardous to small craft will be possible at times from Friday through the weekend on the Bay and Lake.

DISCUSSION
Issued at 332 AM CDT Thu Apr 25 2024

Short Term
Today
Tonight...and Friday

High pressure originating from Hudson Bay will continue to bring dry weather today. Generally a persistence forecast works, in terms of low RH and for the most part light winds though they will be slightly stronger closer to the lake (10-15 mph). High temperatures will rebound, reaching upper 50s to lower 60s most locations west of I-43. Cool exception will be along the Lake Michigan shore, where readings will struggle through the 40s.

High shifts east tonight placing our region in steadier SE flow.
This will result in a warmer night compared to the chilly start to this morning. Lowest temps just below freezing over far northeast WI toward the Upper Michigan border.

On Friday, SE flow increases further as pressure gradient tightens with advance of deep plains low pressure system tied to sharp negative tilted mid-level trough. Even the more aggressive models have come in line with slower solutions the ECMWF/Canadian were indicating. Net result is showers will gradually spread northeast into WI, but most of our area likely will not see rain until mid to late afternoon. SE winds will increase, but soundings show most of the stronger winds will remain just above the sfc so have continued to back off of gusts. Plenty of thickening clouds will keep temps mainly in the mid to upper 50s. Any thunder will hold off until after early Friday evening.

Long Term...Friday Night Through Wednesday

An active pattern is expected Friday night through the weekend as two waves of low pressure move across the region. For Friday night, the slower arrival of the rain will make into far northeast Wisconsin by mid to late evening. The better instability arrives after midnight with most unstable CAPE values of at least 200 to 700 J/KG. 0-6km shear values off bufkit soundings were from 30 to 40 kts. Wet bulb zero heights off bufkit soundings were around nine thousand feet, thus not exceptional high. Model qpf output would also suggest that discrete cells would be anticipated with the northward push of the warm front. These types of event would support storms that would produce hail. With the boundary layer only in the upper 40s to lower 50s, some of the hail stones could approach 1 inch.

The models are still insistent that the warm front will push north across much of the area late Friday night and Saturday morning. Still worried that portions of northeast Wisconsin from Oconto and Marinette counties through Door County may not see a true frontal passage into the warm air due to the southerly wind component and stronger stable layer off the colder waters of the bay and Lake Michigan. There should be scattered showers and storms around during the morning, and some of these storms could be on the stronger side with hail. Attention then turns to Saturday afternoon and evening as temperatures warm into the 70s. Bufkit soundings would support at least 1,000 to 2,000 J/KG of surface based CAPE in the warm sector along with 0-6km shear values of 30 to 45 knots. Strong or severe storms are possible with damaging winds and large hail as the cold front moves east across the area Saturday afternoon into Saturday evening. The latest SPC Day3 risk has outlined much of our area for a slight risk (level 2/5) for severe weather. Later Saturday night, the frontal boundary is expected to sag southward due to the movement of the cold front, and will likely be aided in outflow boundaries and some effects of the cooler air mass off the bay/lake will likely result in the boundary sinking further south than what the models indicate.
There will be a lull in rainfall later Saturday evening and overnight before the next round of showers and storms moves across the area Sunday.

There is still a lot of uncertainty in the risk of severe weather on Sunday depending on how far south the front sinks Saturday night.
If the models are correct, the warm front will push north across the area on Sunday which could lead to another round of strong or severe storms. Unsettled weather will continue into Monday before dry conditions return Monday night. Next system arrives Tuesday PM with a chance of showers and possibly a few storms with another system arriving on Wednesday.

AVIATION
for 06Z TAF Issuance Issued at 1005 PM CDT Wed Apr 24 2024

Dry Canadian high pressure will bring VFR conditions to the forecast area through the TAF period, with only some high clouds moving through overnight. Light and variable winds will become SE-S and increase around 10 knots on Thursday.

FIRE WEATHER
Issued at 332 AM CDT Thu Apr 25 2024

Elevated fire weather conditions are likely today as RH values are expected to drop into the 20 to 30 percent range and fuel moisture remains fairly low. Concerns are somewhat tempered with temperatures only forecast to warm into the mid 50s to lower 60s and southeast winds only increasing to around 10-15 mph this afternoon, strongest near the lake where temperatures will remain below 50. Overall, do not expect conditions to meet critical fire weather thresholds.

On Friday, elevated fire weather conditions are possible, at least for parts of the area. The arrival of rain with the next system continues to slow, only reaching central Wisconsin in the afternoon.
Thus, areas from far north-central to northeast Wisconsin closer to the Upper Michigan border could stay dry all day and may see RH values as low as 30 percent into mid afternoon with SE winds to 15 mph gusting to 25 mph.

GRB WATCHES/WARNINGS/ADVISORIES
None.

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