754
FXUS63 KARX 070657
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
200 AM CDT Fri Jun 7 2024

.KEY MESSAGES...

- Rain chances move in for parts of southeast MN/northeast IA later
this afternoon, but more widespread overnight/Sat morning. Only a
low end thunder threat (10-20%) with rain amounts mostly 1/4" or
less.

- Relatively cool weekend into the start of new work week (highs 60s
to low 70s for most) but turning warmer for the latter half.

&&

.DISCUSSION...
Issued at 200 AM CDT Fri Jun 7 2024

* OVERVIEW:

Upper level longwave trough over the great lakes/new england states
will persist as various shortwaves drop into the trough, re-
enforcing/carving it out. This setup will continue to funnel
relatively cool air southward from Canada while the shortwaves and
afternoon instability work inconcert to spark a few showers from
time to time. Thunder chances relatively low moving into next week.

The long range guidance remains steadfast in breaking down the
blocking pattern as we move into the middle part of the new week,
with broad upper level ridging/zonal flow taking over. Heights climb
as does low level warming. How strong the ridge becomes, and where
it moves/centers itself is not clear. WPC cluster analysis suggest a
few different ways this may play out - which could result in steamy
temps locally, or just more moderate warming. The EPS and GEFS
members don`t have much of a preference at this time, dropping
members in all 4 clusters. Will let the model members details temps
for the time being.


* WEEKEND RAIN CHANCES - most likely late tonight/Sat (60-80%). Only
  a low end thunder threat (10-20%).

A bit of upper level energy is progged by the short/medium range
range guidance to slide east out of the southern rockies today,
shifting across IA by late afternoon/evening. Some low level warm
air advection and mid level frontogenetic forcing with the feature.
Good fetch of low level moisture return into the shortwave as 30 kt
850mb jet noses into northcentral IA. Pool of instability holds
southward of the systems associated sfc warm front.

CAMS models develop a northwest-southeast running bkn line of
showers in response to the forcing/moisture interaction, but mostly
mid level variety. Higher convective threat lies south/southwest of
this band.

Moving into the overnight another shortwave trough looks to drop out
of southern Canada and move across the upper mississippi river
valley. Weak low level thermodynamics but some upper level QG
convergence to work with. Sensible weather impacts come in the form
of widespread showers, move favored across parts of MN and WI.

Other, small bits of upper level energy and weak afternoon
instability could continue spotty shower chances from time to time
Saturday afternoon through Sunday, but not a lot of consensus in the
models on how this will play out.


* RAIN CHANCES FOR NEW WORK WEEK? mixed messages in the models,
  lower confidence

How the rain potential plays out for next week is unclear as the
upper level ridging works in. Some of the GEFS and EPS bring rain
chances to the region while other members favor dry conditions. Not
a clear signal eitherway in movement/track of any upper level
disturbances, and confidence isn`t high in any particular period
over another. Will hold with the blend for the details for now.


* COOL THIS WEEKEND INTO EARLY NEXT WEEK - but looking warmer by
  week`s end

The cool low level air that settled across the region Thu looks to
hang around through the upcoming weekend and into the early part of
the new week. Still looking at highs approx 5 to 10 degrees below
the early June normals - mostly topping out in the upper 60s to
lower 70s.

With broad ridging building in as we move into the middle part of
the new week, increasing heights with corresponding bump in temps
promises a return to the seasonable normals, if not exceeding them
by 5 to 10 degrees. Consistent signal in the long range guidance to
warm back into the 80s while the GEFS and EPS suggest a 5 to 10%
chance to push 90 for a few locations by the new weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1040 PM CDT Thu Jun 6 2024

VFR expected across the local forecast area from southeast
Minnesota, northeast Iowa, and western into central Wisconsin.
Increased winds through Friday, albeit not as strong as Thursday.
Subsequent flight impacts and precipitation overnight Friday into
Saturday morning.

&&

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

&&

$$

DISCUSSION...Rieck
AVIATION...JAR