Sunrise 5:50 AM   Sunset 8:03 PM Moonrise 12:26 AM   Moonset 8:38 AM

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FXUS63 KARX 291035 AFDARX

Area Forecast Discussion National Weather Service La Crosse WI 535 AM CDT Mon Apr 29 2024

KEY MESSAGES

- Cooler weather today, with a rebound to above average temperatures for Tuesday and Wednesday. Seasonal temperatures for the remainder of the week.

- Several more rounds of showers and storms are lined up for Tuesday and late Wednesday through Friday. Overall severe threat looks low at this time, however the likelihood of widespread rainfall is high (between 60 and 90%) with these systems.

DISCUSSION
Issued at 337 AM CDT Mon Apr 29 2024

Today through Tuesday:

The surface low continues to move off to the northeast during the day. The progression of the low slows a little bit, allowing for some showers to be possible for areas along and north of I-94 through the day. Shortwave ridging will move over the area, however with low stratus hanging around for most of the day, temperatures will be on the cooler side. Heading into Tuesday, a compact shortwave trough will dip down into the Central Plains.
This will be our next chance at seeing some precipitation.
Accompanying this shortwave will be dewpoints ranging from around 50F to the low 50s, especially in northeast Iowa and southeast Minnesota, a 50kt low- level jet, and good shear. The one ingredient that is missing is instability. The greatest instability lies west of the area in northwestern Iowa. There is still some uncertainty in how far north the instability and moisture transport gets. This will help in determining if severe weather will be possible across the area. Combining the above ingredients with recent model guidance that has a few hundred joules of SBCAPE across northeastern Iowa and southeastern Minnesota, SPC has gone with a Marginal risk (level 1 of 5) in this area. Even though the severe threat is low, general showers and thunderstorms seem likely during the evening and early overnight hours on Tuesday into Wednesday.

Active Pattern Continues:

By Wednesday, a longwave trough shifts eastward. This will allow for deeper moisture transport and warm sector spreading northward.
Periodic precipitation will be possible given this regime through the end of the week. It is too early to tell if severe weather will be possible, however the current guidance gives the Central Plains the best chance at seeing severe weather through the week. That being said, rainfall probabilities continue to increase. They have increased slightly from the previous forecast. The Grand Ensemble gives a 50% to 70% chance of at least 0.5" and 25% to 40% of at least an 1" occurring Thursday into early Friday.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
Issued at 535 AM CDT Mon Apr 29 2024

LIFR/IFR ceilings and patchy fog will give way to slowly rising ceilings today into the MVFR range, although low (20-30%)
chances for IFR ceilings persist at KRST even into tonight. Some clearing of the broad stratus shield may occur overnight, but with lower confidence in timing of clearing, held onto MVFR for now. Winds will shift to the southwest today, with some gusts up to 25 kts, especially at KRST, before winds slacken this evening.

ARX WATCHES/WARNINGS/ADVISORIES
WI...None.
MN...None.
IA...None.

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