Sunrise 5:45 AM   Sunset 7:50 PM Moonrise 12:00 AM   Moonset 7:35 AM

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LMZ643 Sheboygan To Port Washington Wi- 105 Am Cdt Sat Apr 27 2024
.small craft advisory in effect through Monday evening - .
Rest of tonight - South wind 10 to 20 knots. Gusts up to 25 knots. Chance of showers and Thunderstorms. Waves 6 to 8 feet.Saturday - South wind 15 to 25 knots veering southwest late in the afternoon. Gusts up to 30 knots. Slight chance of showers through the day. Slight chance of Thunderstorms in the afternoon. Waves 6 to 8 feet subsiding to 5 to 7 feet in the late morning and early afternoon, then subsiding to 4 to 6 feet late in the afternoon. Saturday night - Southwest wind 10 to 20 knots becoming 10 to 15 knots late in the evening, then becoming west 5 to 10 knots after midnight becoming north 10 to 15 knots early in the morning. Rain showers likely and a chance of Thunderstorms. Waves 3 to 5 feet subsiding to 1 to 3 feet. Sunday - Northeast wind 10 to 15 knots rising to 15 to 20 knots in the late morning and early afternoon, then becoming northeast 15 to 20 knots late in the afternoon. Rain showers and slight chance of Thunderstorms. Waves 3 to 4 feet.

LMZ600
No data

FXUS63 KMKX 270243 AFDMKX

Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 943 PM CDT Fri Apr 26 2024

KEY MESSAGES

- Multiple rounds of showers and thunderstorms are expected tonight through the weekend, with storms possibly lingering into early Monday. Locally heavy rainfall will be possible, especially south and west of Madison.

- A few thunderstorms may be severe during this active pattern, particularly later Saturday through Sunday.

- Additional chances for showers and storms mid to late week next week.

UPDATE
Issued 940 PM CDT Fri Apr 26 2024

Continue to monitor for thunderstorm potential tonight as the surface low lifts into MN lifting a warm front across southern WI. Trends continue to slow this northward progression of the warm front as it is currently draped across southern IA through central IL. Latest 00z models coming in have the front lifting in later than previous forecast around 04z-06z. However there is still a question on if anything develops along this frontal boundary as it moves into a more stable environment. Thus the later the arrival of the surface warm front the less likely to see thunderstorms develop along this boundary as hinted at by the 00z ARW. However most of the other incoming 00z models such as the HRRR and NAM Nest have at least a few showers and storms developing after 04z and quickly moving through the area as LLJ lingers paired with low-level WAA and an approaching warm front.
00z Rap still tries to bring in a nose of 250-500 J/kg of instability, thus still can't rule out a few storms to produced some small hail. Otherwise, with a stronger, 45-55 kt LLJ, cannot rule out some gustier winds with any thunderstorms as well.

Overall, the best thunderstorm chances remain along and west of the I-39/90 corridor tonight, but the later arrival trends continues to limit the potential for any stronger storms. This activity should diminish by 09z as the warm sector settles into the region. Drier, warmer conditions look to persist into Saturday before the cold front moves into the region and triggers another round of showers and storms.

Wagner

SHORT TERM
Issued 356 PM CDT Fri Apr 26 2024

Tonight and Saturday:

Rain showers continue to push in from the south, with some rumbles of thunder embedded throughout the system. Current low level profiles remain drier while the upper levels moisten with the oncoming rain, helping to keep rainfall values around light to moderate across the area. This rain will continue to push in throughout the afternoon and evening, before a brief reprieve as it traverses towards the northeast.

Behind this initial band of rain, more rain follows the warm frontal boundary with an associated low pressure currently over Nebraska. With this line of rain, some embedded thunderstorms are anticipated, with greater lift along the boundary and more energy following warm air advection into the region. As the low pressure exits towards the northern Great Lakes region by Saturday morning, temperatures will climb with stronger southwesterly winds prevailing. Isolated thunderstorms are possible in the afternoon hours, although most regions are expected to stay dry. Going into the evening on Saturday, a greater severe threat begins to take shape.

Gertonson

LONG TERM
Issued 356 PM CDT Fri Apr 26 2024

Saturday night through Friday:

Frontal feature hanging over central Wisconsin will slowly sink southward as low pressure approaches from the central Great Plains once again Saturday night. With surface dewpoints in the lower 60s and temperatures in the lower 70s, surface based CAPE values close to 2000 J/kg in the evening hours are possible, with CAPE above 1500 J/kg likely. Mid level lapse rates of 6.5 to 7 degrees C/km lends credence to continued concern for 1 inch or larger hail with the initial convection within the unstable layer. Gusty winds are also possible with this activity as dry air intrudes in the 700 to 500 mb layer and PGF increases ahead of the next low pressure pushing eastward. Increasing helicity ahead of the front (200 to 300 m2/s2) may result in an isolated tornado, although confidence in this hazard remains low.

Frontal convection continues through Saturday night into Sunday, with any individual cells continuing to be capable of producing hail. However, increasing stability in the boundary layer will keep storms elevated and reduce any severe winds or lingering tornado potential. Sunday morning, low pressure begins to sweep northeastward toward Minnesota, bringing better bulk shear (40 to 50 kt) to the area as southerly winds continue to increase.
Cloud cover through the morning may prevent warming, and location of the frontal feature may produce a 10 or more degree F difference in temperature from central Wisconsin to southern Wisconsin. Still, temperatures in the lower 70s and dewpoints in the lower 60s lend credence to another round of thunderstorms in southern Wisconsin Sunday afternoon and evening as WAA and an 850 mb jet act as the main trigger and MUCAPE producers.
Potential for hail and gusty winds are once again in play.

Trends have been slower with the progression of the main cold frontal feature, leading to continued concerns for thunderstorms into Monday. Southerly to southwesterly flow continues throughout Monday morning, with frontal passage currently forecast early Monday afternoon. Temperatures are expected to rise to near 70 degrees across all of southern Wisconsin, with westerly component allowing for warming all the way to Lake Michigan. Uncertainty remains in intensity of convection on Monday due to uncertainty in precursory convection and impact of previous days convection on the propagation of the low.

A brief period of quiet, dry weather on Tuesday, then an additional shortwave comes through the region Tuesday night, with additional shortwaves and perhaps a stronger low pressure system developing and impacting southern Wisconsin through the end of the week.

MH

AVIATION
Issued 940 PM CDT Fri Apr 26 2024

Some light scattered rain is working its way across the area late this evening with another round of scattered showers possible between 04z-09z as a warm front is progged to lift into the southern WI overnight. Cannot rule a rumble of thunder or two with the overnight activity, especially for MSN and JVL terminals. However this window will be brief. Lower ceilings are lingering across southwest and south central WI bring lower ceiling around IFR to MVFR levels, while VFR are more present closer to the Lake. Can see lower visibilities and ceilings drop with and shower that passes over the terminals. Otherwise, will continue to see gusty southeasterly winds tonight turning a bit more southerly more into Saturday morning as warm front lifts north. Flight conditions are expected to improve as ceilings lift with the drier conditions. However, another round of showers and storms, potential strong to severe return later Saturday as a cold front slides across the region bringing back the lower flight conditions.

Wagner

MARINE
Issued 356 PM CDT Fri Apr 26 2024

Low pressure over the central Great Plains will lift into Minnesota tonight, with gusty southeasterly winds expected. A few gusts late tonight into Saturday morning may approach gale force, especially in the northern half of the Lake, as the low continues to lift into Lake Superior. Winds will then become light and northeasterly Saturday night into Sunday morning as the low exits and a weak cold front drapes across central portions of the lake. Sunday into Sunday night, winds will become breezy and southerly south of the front and will become breezy and easterly to northeasterly north of the front. A Small Craft Advisory is in place through Monday for gusty winds and elevated wave conditions. A lull may occur late Saturday night into Sunday, with increased gustiness once again Monday.

A few thunderstorms are possible this evening into tonight across the southern half of the lake, lifting into the northern half Saturday morning. Additional rounds of showers and thunderstorms are expected Saturday and Sunday. A few storms in the afternoon hours could produce locally gusty winds.

MH

MKX WATCHES/WARNINGS/ADVISORIES
WI...None.
LM
Small Craft Advisory
LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM Monday.

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