Necedah, Wisconsin Weather Forecast Discussion

794
FXUS63 KARX 180859
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
359 AM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Scattered showers and thunderstorms through the weekend with
  potential for higher coverage Friday afternoon/evening and
  Saturday afternoon.
- Warmer temperatures continue through Thursday with highs
  mainly in the 80s, then drop into the 70s through early next
  week.
&&
.DISCUSSION...
Issued at 358 AM CDT Thu Sep 18 2025
Rain potential through the weekend:
Through Sunday, upper ridge to our east will break down with
multiple waves aloft passing over the CWA as an area of persistent
troughiness finally breaks eastward. Most favorable periods for
precip will unsurprisingly focus on when these waves pass - at this
time, this appears to be tonight, Friday afternoon and evening,
Saturday afternoon, and during the day Sunday. However, with a moist
airmass in place - 18.00z MSP RAOB measured 1.5" PWAT and the 18.00z
HREF has mean PWATs hovering around 1.4" through Sunday - coupled
with cooling temperatures aloft may lead to sporadic convection over
the entirety of the next 3 days. Available moisture may also lead to
localized heavy rainfall as storm motions remain around 15 mph or
less over the next 2 days are favored with motion ticking upward as
flow aloft ramps up for Saturday and Sunday. This may also introduce
a highly conditional low-end potential for a severe storm this
weekend provided a daytime break in the showers/sky cover and
destabilization occur as sfc-6km bulk shear does increase to around
30 knots. However, this seems like a very doubtful possibility given
likelihood of lingering showers and sky cover through Sunday.
For the first half of next week, guidance suggests a longwave trough
will slide over the central CONUS. While there is broad agreement on
this, finer scale timing and location details remain quite
uncertain. Have therefore retained NBM PoPs and multiple days of
precip mentions through the extended with a view to hopefully focus
on shorter periods for mentions down the road.
Temperatures take a small step downward starting Friday:
With the break down of the ridge to our east underway, today looks
to be our final day with widespread highs in the 80s for the next
week. 18.01z NBM interquartile ranges remain around 4-5 degrees
through Tuesday so confidence is high most locations will see
temperatures in the 70s with the usual warm spots in the Mississippi
Valley potentially touching 80 Friday, Sunday, and Monday.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1231 AM CDT Thu Sep 18 2025
Low confidence TAF due to persistent scattered shower/storm
potential through the 18.06Z period. Radar imagery at 18.06Z TAF
issuance shows an arc of showers quickly progressing north
through southeast Minnesota and western Wisconsin into west-
central Wisconsin. KLSE ASOS registered a Trace with these
passing showers from 0515-0540Z.
The persistent weather pattern causes transient IFR visibility
potential from scattered storms primarily during the daytime
hours today. Higher, widespread storm chances progress east
across the forecast area tonight, as early as the 18-24 forecast
hour. Initial local higher storm chances primarily affect
smaller airports in southeast Minnesota (KAUM, KTOB) and
northeast Iowa (KCCY). Initial timing and eastern extent limits
overall confidence, below mentionable for KRST TAF, and will
need to be further investigated in coming TAFs (12-18hour
forecast).
FRIDAY THROUGH MONDAY.. Widespread, high storm chances Friday
and Friday night (60-80%). Low to moderate storm chances
(20-50%) Saturday through Monday.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Ferguson
AVIATION...JAR

NWS ARX Office Area Forecast Discussion