Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 210509 AAA

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
1109 PM CST Thu Feb 20 2020

Issued at 309 PM CST Thu Feb 20 2020

H5 analysis from earlier this morning had a closed low
over northern Quebec. Immediately west of this feature, a ridge
extended from western Montana into eastern portions of the NW
Territories of Canada. In between these two features, a shortwave
trough extended from southern Iowa into eastern Colorado. A closed
low was noted off the coast of northern California. High pressure
aloft was anchored over western portions of the Gulf of Mexico. At
the surface, high pressure was anchored from SE Nebraska into NE
Kansas. Southwesterly winds had developed on the back side of the
exiting high this afternoon. Clear skies were present everywhere
across western and north central Nebraska. Visible satellite imagery
showed a broad area of snow cover across the sandhills into portions
of central and north central Nebraska, as well as along Interstate
80 from Brady to Chappell. Over the past couple of hours, the snow
field has shrunk some on the northern and southern portions.
Temperatures remain cool however, especially over the snow field.
Temperatures as of 2 PM CT ranged from 29 at O`Neill and Thedford to
42 at Valentine.


.SHORT TERM...(This evening through Friday night)
Issued at 309 PM CST Thu Feb 20 2020

Temperatures will be the main
forecast challenge in the first 36 hours of the forecast period.
Much warmer air will push into the forecast area behind a surface
trough tonight. Winds behind this feature will swing around to the
west and southwest. The Hi res models including the NAM12 soln
develop some stout winds just off the surface tonight. Some of these
stronger winds, should mix down to the surface tonight. This will
give a boost to overnight lows compared to this morning`s lows. Lows
will be warmest in the east tonight, where winds are expected to be
stronger. Winds will be lighter in the west and southwest, thus the
cooler lows in these areas. As for fog potential tonight, wouldn`t
be surprised to see some develoment in river valleys tonight where
winds will be lighter. However, the latest Hi res model solutions,
do not indicate fog development whatsoever. That being said, will
leave out a mention of fog in the forecast for river valleys and
have the evening forecast crew watch this closely tonight. Winds
will remain light from the west on Friday. With lighter winds
forecast and limited mixing, trended temps toward the cooler end of
guidance and undercut guidance further in the Sandhills where snow
cover is expected to remain in place Friday. Highs will be in the
mid to upper 40s in snow covered areas with highs in the lower to
middle 50s over non snow covered areas.

.LONG TERM...(Saturday through Thursday)
Issued at 309 PM CST Thu Feb 20 2020

The pattern will become much more
active during the latter half of the weekend. This active pattern
will carry over into the middle of next week as a tandem of weather
systems cross the central and northern plains. Conditions will be
tranquil on Saturday, thanks to a low amplitude ridge which builds
into the central plains. This is in advance of a closed low which
will cross southern California Saturday. Highs Saturday will reach
well into the 50s. Across the central Sandhills, highs may need to
be modified down in these areas if snow can`t totally melt off on
Friday. Believe total snowmelt is possible on Friday though, given
the low water content of the snow which fell yesterday. On Saturday
night, the H5 low will cross the Four Corners, entering southern
Colorado. Beyond Saturday night, there are some subtle differences
in the track of the H5 low with this system. The NAM12 soln is
farther north, tracking the H5 low over Central Kansas. The GFS is a
compromise between the NAM12 and ECMWF/Canadian solutions.
Regardless, based on the latest model trends, the bulk of
precipitation with this system favors the far southern portion of
the forecast area. As for snow or rain with this system: There is no
northern stream influence with this system, so it will be a "warm"
system by February standards. This may limit the snow threat on the
northern side of the low and keep the threat tied into the non
daylight hours. That being said, the snow forecast is limited in the
south and confined mainly to Saturday night with a rain threat for
Sunday. On the heels of this system, a northern stream system will
drop southeast across the northern and central plains Monday night
into Wednesday. This system has a better potential for Snow as it
has an arctic tap of cold air with it. There are still some model
differences with the track and associated forcing for precipitation.
ATTM, this remains a fairly low confidence forecast for pcpn. Monday
night through Wednesday. One aspect that remains fairly constant is
the sharp cooldown for next week.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1109 PM CST Thu Feb 20 2020

VFR is expected throughout wrn and ncntl Nebraska overnight,
Friday and Friday evening.

Very dry air aloft and near the sfc will promote clear skies
during this time.




SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...CDC is the U.S. government's official web portal to all federal, state and local government web resources and services.