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 46 47 48 49 50
FXUS63 KARX 161118

Area Forecast Discussion
National Weather Service La Crosse WI
618 AM CDT Wed Oct 16 2019

.SHORT TERM...(Today and Tonight)
Issued at 317 AM CDT Wed Oct 16 2019

At 3 AM, cyclonic flow, associated with the closed low pressure
area over Lower Michigan, kept skies mainly cloudy across the
Upper Mississippi River Valley. In addition, there were scattered
rain showers across central Wisconsin. The rain will be moving
east of the area this morning as the upper level low moves east
into Lake Huron. While the low will be exiting the area, moisture
will remain trapped underneath the subsidence inversion. As a
result, we will remain mainly cloudy until the 950 to 850 mb
ridge moves east of the area. This will not occur until tonight.
High temperatures will be mainly in the 40s today. Lows on
Thursday morning will be in the lower to mid-30s.

.LONG TERM...(Thursday through Tuesday)
Issued at 317 AM CDT Wed Oct 16 2019

On Friday, the combination of a tight surface gradient and
sunshine will allow mixing to occur. The main question is the
depth of this mixing. The NAM would suggest up to 900 mb.
Meanwhile, the GFS soundings are showing that it will be up to
800 mb. For now, opted to mix up to 900 mb which would generate
high temperatures in the 60s. This is about 5F warmer than MOS
guidance. If we happened to mix even deeper, these temperatures
may be too conservative and we could over perform.

From Friday night into Saturday, the models are currently
indicating that the Pacific cold front will move to the east much
faster. This could potentially result in much of Saturday
remaining dry. Due to this, started lowering the rain chances east
of the Mississippi River and removed them across the remainder of
the area on Saturday afternoon.

From Sunday night into Monday, a stronger shortwave trough will
move through the region. Unlike yesterday, the models are in much
better agreement that the upper level low will move northeast
across northwest Minnesota. In addition, they are better in
agreement that the best moisture transport will be well east of
the area, thus, the rainfall amounts (maybe up to a half inch)
look less for the area. With 0-1 km CAPES up to 500 J/kg, kept the
mention of scattered thunderstorms in the forecast for Sunday
night and Monday morning.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 618 AM CDT Wed Oct 16 2019

Fairly widespread stratus remains in place across the area this
morning and is in no hurry to leave today. We have seen a few
holes in the clouds at times, though expect those will fill in
over the next few hours after the sun rises, leaving mainly MVFR
ceilings in place by late morning into early afternoon before
gradually lifting back to VFR into the evening as high pressure
approaches. Based on current conditions, we`ll likely even see a
brief window of IFR ceilings at RST, though don`t expect that will
last any longer than 15Z. Otherwise, gustier northwest winds 10-20
knots today will give way to lighter conditions tonight as high
pressure builds into the region.




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