Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 151113

Area Forecast Discussion
National Weather Service La Crosse WI
513 AM CST Thu Feb 15 2018

.SHORT TERM...(Today through Tonight)
Issued at 305 AM CST Thu Feb 15 2018

Surface map early this morning has a cold front extending  from Lake
Superior through northern MN, and then along the ND/SD border.
Meanwhile, a weak area of low pressure was along the NE/KS border
and was spreading high clouds into areas along and south of I-90.
Otherwise, southwest surface flow was keeping temperatures quite
mild as of 2 am with readings in the 30s.

For today, we`ll see the cold front slip southeast through the
region with that weak area of low pressure rippling northeast
through IL. Push of moisture ahead of the low and the advancing cold
front will increase cloud cover across the area but any
precipitation should remain south. Despite cold frontal passage, warm
start today should yield highs in the middle 30s to the lower

Models still show a weak mid-level trough passing through the
region this evening for a small-end chance of light snow or
scattered snow showers. Maintained a 20-40 pop to cover this.
Stronger cold air advection and clearing skies behind this wave
will drop lows into the single digits above zero.

.LONG TERM...(Friday through Thursday)
Issued at 305 AM CST Thu Feb 15 2018

Friday will be sunny but colder as high pressure builds southeast
from the Northern Plains. Plan on highs in the teens to lower 20s.

Next chance of precipitation in the form of snow showers will be
late Friday night into Saturday as a cold front slips southeast
through the area. Look for lows Friday night in the single digits
and teens with highs Saturday in the upper 20s to the middle 30s.

Sunday looks quiet/dry as high pressure drifts across the region.
with highs topping off in the upper 20s to the middle 30s.

A storm system ejects northeast out of the Rockies into the region
Monday through Tuesday. Precipitation types/impact on the area a bit
uncertain at this time due to differing temperature profiles between
the models. Right now, will have to call it a wintry mix and dial in
more detail over the next couple of days.

Wednesday through Thursday looks dry with slightly below normal


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 513 AM CST Thu Feb 15 2018

As an area of low pressure over Kansas moves into Missouri early
this morning, will have to monitor an area of very light winds on
the northeast side of the low where fog has formed. MVFR/IFR
visibility reductions have primarily stayed south of both
airports, but there is the potential for these to briefly form
this morning until the gradient starts to pick back up again. The
winds should swing around to the west and start to increase early
this morning once a trough of low pressure moves through, so think
it is a very short period when fog could impact the airports and
do not plan to include it for now. A cold front dropping south
across Minnesota will move through early this afternoon and swing
the winds around to the northwest. The front will be closely
followed by MVFR/IFR ceilings and possibly a little bit of light
snow/flurries. With the lower clouds already occurring behind the
front, fairly confident that the lower ceilings will impact both
airports. Confidence in the light snow/flurries is too low to
include at this time. Good low level lapse rates develop in the
mixed layer behind the front for some gusts through the night at
both airports.




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