Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
000
FXUS63 KARX 251938
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
238 PM CDT Mon Mar 25 2024

.KEY MESSAGES...

- Precipitation transitioning to all snow Tuesday. Brief period
  of wintry mix before changing to all snow. Snow accumulation
  is expected to be less than an inch.

- Fog is possible tonight

- Temperatures will remain below normal Tuesday into Wednesday.

- Periodic rain and snow chances Friday into next weekend.

&&

.DISCUSSION...
Issued at 223 PM CDT Mon Mar 25 2024

Tonight into Tuesday

Latest 18z surface analysis shows low pressure over western Iowa.
Out ahead of the low pressure...decent moisture
transport/convergence has produced rain across much of the forecast
area...per latest mosaic radar. Surface low will lift northeastward
into central Wisconsin tonight into Tuesday. Latest 25.12z
deterministic GFS/NAM and hi-resolution models show decent 925-850mb
moisture convergence and forcing associated with the surface low.
Based on bufkit soundings...precipitation should remain all rain
tonight across the forecast area. With saturated boundary
layer...due to snow melt and influx of moisture near the surface.
There is potential of fog formation late this evening and overnight.
Have introduced patchy fog across the forecast area.

Surface cold front extending south from the surface low will track
across the forecast area Tuesday. Colder airmass advects into the
area along and behind the cold front. The rain will transition over
to all snow just behind the cold front. Latest bufkit soundings
indicate there could be a brief period of freezing rain/ice pellets
before changing to all snow along the cold front. Ice accumulation
are expected to be a couple of hundredths. As surface low/cold front
tracks north and east of forecast area...a frontogenetical band
develops and rotates around the southern periphery of the surface
low. Latest hi resolution models suggest this band to move rather
quickly across the northern half of the forecast area and can expect
less than an inch of snow accumulation into Tuesday evening.

Wednesday into Thursday

With the colder airmass filtering into the region Wednesday...expect
temperatures to be well below normal. The 25.12z GFS/NAM show 925mb
temperatures falling to minus 3 to minus 10 degrees celsius by 00z
Thursday. High temperatures will rise into the upper 20s to upper
30s. Slightly warmer airmass advects into the area Thursday...as a
shortwave ridge builds into the Northern Plains States. Temperatures
are expected to warm back up into the middle 30s to upper 40s.

Thursday night through Monday

Main forecast concerns Thursday night through Monday are
precipitation chances through the period. West to east zonal flow
develops across the northern tier United States through the
forecast period. Ensemble members and latest 25.12z
deterministic models show differences in strength of shortwave
ridges/shortwave troughs embedded in the west to east zonal flow
aloft. This will have impacts on timing of precipitation
chances through the period...though given west to east zonal
flow pattern...pieces of energy will track over the forecast
area Thursday night into Monday. This will provide periodic rain
snow chances across the forecast area. Temperatures through the
period are expected to be near or slightly below normal...with
high temperatures climbing into the middle 40s to middle 50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1146 AM CDT Mon Mar 25 2024

Expect periods of showers through the period, with a transition
to snow Tuesday morning from the west. A brief period of a mix,
including freezing rain/sleet is possible during this transition
at KRST, but confidence is low at this time. An isolated
thunderstorm (10-20% chance) could also occur through this
evening.

Otherwise, expect deteriorating conditions through tonight with
ceilings ranging from LIFR to MVFR and IFR/MVFR visibility at
times. Given the moist low-levels and lighter winds overnight,
some potential for fog exists, perhaps dense in spots.

East to southeast winds will swing around to the west to
northwest on Tuesday with some gusts of 20 to 30 kts by Tuesday
morning west of the Mississippi River.

&&

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

&&

$$

DISCUSSION...
AVIATION...JM


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.