Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 160525

Area Forecast Discussion
National Weather Service La Crosse WI
1125 PM CST Wed Feb 15 2017

.SHORT TERM...(This evening through Thursday)
Issued at 250 PM CST Wed Feb 15 2017

Deep northerly flow has brought a brief cool down closer to
average temps today. The cooler temps will be short-lived with
1000-850 mb warm advection already increasing across western
Minnesota/Iowa. The warmer air will continue to spread eastward
with 925 mb temps increasing by around 7C between this afternoon
and Thursday afternoon as surface high pressure moves east of the
area and an upper level ridge shifts eastward from the plains.
Temps will fall into the teens to mid 20s tonight before
recovering into the 30s and 40s on Thursday. Some primarily mid-
level cloud cover associated with 700 mb frontogenesis/warm
advection will stream across the area through early Thursday with
otherwise just some high cirrus at times. Although the sub-cloud
layer is quite dry, sufficient saturation may occur for some light
snow/flurries this evening in central WI for a time this evening.

.LONG TERM...(Thursday night through Wednesday)
Issued at 250 PM CST Wed Feb 15 2017

No significant changes were needed for the extended forecast, as
models remain in agreement overall with very warm temps through
the period and the primary focus for any precipitation Monday and
Monday night.

Unseasonably warm temps will be the rule through the period. 925 mb
temps spike between 10-15C by late Friday helping boost highs into
the 50s for much of the region. A weak surface high will impact the
area on Saturday as an upper shortwave moves across southern Canada.
Upper level ridging and return low-level flow will commence once
again Sunday and Monday. Expect highs to remain generally in the 50s
over the weekend, possibly near 60 in spots. Guidance has shown a
pretty substantial range in temps through early next week, so
exactly how warm it gets will be interesting to watch.

15.12Z models continue to indicate energy from a western trough
splitting with a piece of energy eventually closing off over south
Texas and another wave riding across the Canadian border region.
The overall trend with the system seems to be a bit slower, although
the 15.12Z GFS is noticeably faster than the ECMWF. With the primary
surface low passing well north, most of the showers would occur
along the progressive surface trough/cold front, which may limit
amounts, despite the anomalously high precip water values for mid-
February around an inch. Could not rule out a clap of thunder,
either, with dew points rising to near 50 and a bit of elevated
instability. Monday also may be the warmest day as strong low-level
warm advection continues ahead of the approaching low pressure
system, allowing temps to begin the day Monday possibly well into
the 40s. Temps may have a better chance of breaking 60 on Monday,
depending on exactly how the timing of low pressure system pans

It looks like temps will remain well above average through the
middle of next week with broad ridging/zonal flow. The global models
differ with timing/placment of any weaker upper shortwaves, so
confidence in precip is low Tue/Wed at this time.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1125 PM CST Wed Feb 15 2017

VFR conditions set to continue the next 24 hours with residual mid
level clouds east of the Mississippi River departing the next few
hours as some thicker bouts of cirrus push overhead at times.
Winds remain light at the moment, but will increase from the
southeast at 10-18 knots (highest at RST) through the day before
subsiding once again this evening.


Issued at 351 AM CST Wed Feb 15 2017

Well above normal temperatures Thursday through Tuesday will put a
major hurt on or get rid of whatever snowpack is left across the
area. This snowmelt combined with a frozen layer of ground is
expected to runoff into area streams and rivers. No flooding is
expected at this time but within bank rises are likely along with
the potential for a few ice jams due to ice break-up. Those with
interests along streams and rivers will want to keep up with the
latest forecasts.




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