Area Forecast Discussion
Issued by NWS La Crosse, WI
Issued by NWS La Crosse, WI
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730 FXUS63 KARX 140823 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 323 AM CDT Tue May 14 2024 .KEY MESSAGES... - Wildfire smoke continues to impact the area with some hazy/milky skies overhead today. - Rain chances increase late Wednesday night into Thursday (35-55% probs for 24-hr QPF >=0.25"). - Additional periodic shower and storm chances forecast through the weekend. && .DISCUSSION... Issued at 323 AM CDT Tue May 14 2024 Hazy/Milky Skies & Low Precip Chances South (Early) Today: GOES satellite imagery and RAP progs around 07Z showed an upper level low generally over Missouri, with a few showers still spread across portions of Iowa into Missouri and Illinois. Latest hi-res guidance would continue to keep the majority of showers south of the local forecast area, but have noticed some echos developing along portions of southwestern Wisconsin. Have maintained some small precipitation chances along our south to reflect current observations and guidance from latest hi-res models. The aforementioned system is expected to continue to slowly shift eastward. With winds turning more northeast/east latest HRRR/RAP- Smoke guidance suggests highest concentrations of near-surface smoke will continue to push southwest/west of the local area for today. Though, increased concentrations of smoke aloft will still keep some milky skies around. Mid-week Precipitation Chances: Model guidance suggests shortwave ridging may be in place for the early part of the day Wednesday before shifting eastward. A shortwave trough is forecast to move behind it across the Northern Plains as shortwave energy moving out from the Southern Plains ejects towards the Mid Mississippi Valley. With some increasing moisture and limited instability ahead of the associated surface front, scattered showers and storms are forecast to move across the area. Latest blended model guidance has slightly slowed down the arrival of the showers and storms into the overnight hours Wednesday, with increasing chances (40-70%) into the day Thursday. Right now the risk for severe storms continues to be low for the local forecast area, but will continue to monitor conditions. Additional Precip Chances End of Week - Weekend: The upper level pattern appears to remain progressive through the period as various shortwaves move through. However, significant differences in details are still noted between ensemble solutions, lowering overall confidence in timing and location of any shower and storm chances. In turn, the NBM maintains broad rain chances (20-40%) over the region through the period and we will hold with these for now until details can be refined further. There is also some signal in ensemble guidance for a slight increase in temps across the region for the start of the weekend, with perhaps some potential to see highs into the mid/upper 70s to near 80. However, temperature spread does increase into the weekend as well. Overall, will continue to iron out the details in the coming days as confidence increases. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1037 PM CDT Mon May 13 2024 VFR conditions are expected through the TAF period with some high cirrus and some smoke aloft. Any remaining surface smoke will move out of the region early in the TAF period with increasing easterly surface winds into the morning and afternoon hours to around 10 kts. A disturbance passing to our south may bring in a shower or two into portions of northeast Iowa and southwestern Wisconsin overnight and into the morning hours on Tuesday however both TAF sites are expected remain dry. Winds will begin to diminish during the evening on Tuesday to around 5 kts as diurnal mixing begins to wane. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...EMS AVIATION...Naylor