Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

FXUS63 KARX 240452

Area Forecast Discussion
National Weather Service La Crosse WI
1152 PM CDT THU JUN 23 2016

.SHORT TERM...(This evening through Friday night)
Issued at 154 PM CDT Thu Jun 23 2016

Main forecast concerns are on cloud trends tonight and the potential
for some patchy dense fog.

High pressure will build into the region this evening into the
overnight hours.  Clouds are expected to gradually decrease as
cyclonic flow aloft shifts southeast and the high moves in, they
will be stubborn to clear though.  With the cloudy skies across much
of the areas today limiting mixing, temperature/dew point spreads
will be rather low.  This combined with the clearing skies should
lead to radiational fog which could be locally dense in spots.
Thinking areas that received heavy rainfall over the last 48 hours
would be most susceptible to the fog.

Dry and quiet weather is expected across the area during the day on
Friday with high pressure in control. This will change Friday night
as a warm front lifts into the region as a trough and cold front
approach from the west. 850 MB moisture transport increases across
the area and we should see some elevated thunderstorms develop
Friday night along this moisture transport. NAM forecast soundings
suggest elevated CAPE of around 2000 J/kg when lifting from 850 MB.
If this moisture is real in the model we may see some stronger
storms develop Friday night into early Saturday morning.  These
would be capable of heavy downpours and possibly some hail.

.LONG TERM...(Friday night through Thursday)
Issued at 154 PM CDT Thu Jun 23 2016

A warm and muggy airmass will be in place across the region on
Saturday ahead of a cold front approaching from the west. A few
showers and thunderstorms could be ongoing through the day, mainly
north of interstate 90. We should see a break in the activity from
late morning through about mid afternoon. Then more thunderstorms
are expected to develop along the cold front near the Interstate 35
corridor. Before more storms move in late in the day, we should see
highs climb into mid to upper 80s. With dew point values in the
upper 60s to around 70 making it feel on the humid side.  Showers
and storms are then expected to move into areas along and west of
the Mississippi River late Saturday afternoon into Saturday
evening. These storms then look to spread east into western and
central Wisconsin during the evening hours. Afternoon surface bases
CAPE values look to climb to around 2000 J/kg. Initially shear is
fairly weak but then is expected to increase through the afternoon
hours into the evening, mainly in the 0-3 km layer. 0-3 km bulk
shear values look to increase to around 25 to 30 kts.  We are
expecting multicell storms with the potential for a few line
segments. Main threats look to be damaging winds, perhaps some large
hail, and heavy downpours. Shear values look stronger over northwest
Wisconsin and much of the guidance is convecting in this area.
The thunderstorms will then sweep through the area from west to
east across the area through the evening hours and exit overnight.

Breezy westerly winds are expected across the region on Sunday in
the wake of the cold front. It looks to be another warm day with
drier dew points in the 50s and 60s. Cooler air then moves in for
Monday with highs falling back into the 70s to around 80. Dry and
pleasant weather looks to be the rule for much of next week with
northwesterly flow in place. Highs temperatures are expected to
remain in the 70s through much of the week.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1152 PM CDT Thu Jun 23 2016

With clearing skies and winds becoming light/calm overnight as
high pressure settles over the region, focus is on fog potential
at both KRST/KLSE. Dew point depressions of 2 to 3 degrees as of
24.05Z are also favorable for fog development. As a result, added
TEMPO groups at both TAF airfields from 24.09Z to 24.12Z with LIFR
ceilings/IFR visibility. If dense fog can develop, visibility to
1/4 mile is likely, but confidence not high enough to include at
this time. Once fog dissipates Friday morning, expect mostly sunny
skies with some scattered afternoon cumulus. Winds will increase
slightly from the southeast.


.ARX Watches/Warnings/Advisories...


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