Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 121931
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
130 PM CST Sun Feb 12 2017

.SHORT TERM...(Tonight through Wednesday)
Issued at 130 PM CST Sun Feb 12 2017

Models in lock-step with dropping a bit of upper level energy
southeast from Canada, spinning it across northern parts of the
region Monday night. Northeast-southwest running x-section across
the forecast area shows little/if any saturation to play with, and
don`t expect much impact locally from the shortwave - perhaps some
snow chances across northern WI.

Another, stronger shortwave will drop southeast across the northern
Great Lakes Tuesday, sliding east toward the New England states for
Wed. Some qg convergence in the 700:300 mb layer, along with
frontogenetic forcing on the leading edge of the wave. The bulk of
the better/deeper forcing is currently progged to move across
northern/eastern WI. Again, saturation an issue. Same x-section
shows some increase in mostly sub 850 mb moisture across the local
area, with the deeper, more pcpn-supportive rh well north-east.
Maybe some small pcpn chances along/east of I-94, but rest of the
area looks dry at this time.


.LONG TERM...(Thursday through Sunday)
Issued at 130 PM CST Sun Feb 12 2017

Its all about the heat.

Strong upper level ridging slated to build in from the Plains for
next weekend, with the ridge axis overhead by 18z Fri, slipping east
Sat. A lot of unseasonably warm air slated to accompany the ridge
with 850 mb temps progged to max out around +10 C or so. NAEFS 850
mb temp anomalies hover from +1 to +2 for the weekend. Snow cover
roughly 1 to 6 inches across the forecast area, and expect a lot (if
not most) of that to melt off over the next several days. With skies
looking mostly sunny for the weekend, and eliminating the snow cover,
the setup is ripe for highs more reminiscent of early April rather
then mid February. The EC is a lot more aggressive with its warming,
suggesting some 60 degree temps are possible. The GFS is 10 degrees
colder while also showing quiet a spread in its ensemble members
(for instance,  from 51 to 30 for highs on Sat at La Crosse).
Eitherway, much above normal. Will start with the model blend for
temps, but increase a bit toward the warm EC.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday noon)
Issued at 1133 AM CST Sun Feb 12 2017

Main concern this TAF period will be the winds. Good VFR expected
this period as dry/cooler Can high pressure builds east across the
region, with any clouds thru mid-day monday mainly sct cirrus.
Concern this TAF period is the brisk NW winds on the east side of
the high. Period starts out with NW winds around 20kt G30kts. These
winds to already start diminishing after 21z, then continue to
diminish thru the evening as the sfc ridge axis approaches, becoming
south and SW 5-8kts later tonight as the ridge axis passes. S and SW
winds to increase by later Mon morning into Mon afternoon with
diurnal warming/mixing and some tightening of the pressure gradient
over the area.

&&

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

$$

SHORT TERM...Rieck
LONG TERM....Rieck
AVIATION...DAS



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