Area Forecast Discussion
Issued by NWS North Platte, NE

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117
FXUS63 KLBF 112121
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
321 PM CST Mon Dec 11 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 320 PM CST Mon Dec 11 2017

Surface high pressure will build into the region tonight with winds
rapidly decreasing. Dry airmass remains in place across western and
southwest Nebraska, and low temperatures in these areas will drop
quickly into the upper teens and lower 20s. Airmass farther east
across north central Nebraska is a bit more moist, and lows should
reflect that in the mid 20s.

Very nice day expected Tuesday, with light westerly downslope winds
around 10 mph. Warmer air aloft will advect in from the west, with
850mb temperatures rising in the 7C to 11C range. Highs will be very
mild in the 50s, with perhaps lower 60s across western portions of
the area.

.LONG TERM...(Tuesday night through Monday)
Issued at 320 PM CST Mon Dec 11 2017

The morning model runs presented a "surprise" for Thursday
suggesting a disturbance across the Gulf of Alaska will ride up and
over the Wrn U.S. ridge and dive south through the Great Plains.
Heights lower and the system carries moisture south producing light
snow Thursday, mainly across northern Nebraska. Although h10-5KM
thicknesses fall to 530 DM, the models still advertise highs in the
upper 30s. 500m AGL temperatures fall to around 0C which supports
highs in the 30s. Thus road surfaces may not fall below the freezing
mark and QPF in the models is generally 1/10 of an inch or less
supporting light snow.

Strong winds are expected both Wednesday and Thursday with winds in
the 850-700mb layer increasing to 40-65 kt. The 500m AGL winds
increase to 20 to 30 kt each day supporting sfc winds in the 20 to
30 mph range gusting to 40-45 mph. The wind forecast uses consensus
of model output statistics for the wind forecast.

Tuesday and Friday are quiet interludes to cold fronts moving
through the region. Another front will arrive Saturday or Sunday.
Model timing differences increase to 18-24 hours by next weekend.
The forecast keeps this frontal passage dry but the models appear to
be trending toward a wetter pattern as the GFS, ECM and Canadian
models are advertising a period of light snow with this frontal
passage.

The temperature forecast uses the model blend plus the previous
forecast plus bias corrected guidance for highs mostly in the 40s
and 50s. Bias correction had tended to nudge forecast highs and lows
up or down a degree or two.

None of the models indicate any kind of direct arctic air moving
into ncntl and wrn Neb. Thursday will be the coolest day with highs
rise in the upper 30s to mid 40s. This is still above normal.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1240 PM CST Mon Dec 11 2017

MVFR ceilings have moved south into northern Nebraska. Expect
these ceilings to remain until the early evening hours, when they
will lift and skies begin to clear. Otherwise strong gusty
northwest winds this afternoon, with sustained speeds 20 to 25 kts
and gusts to 40 kts possible.


&&

.FIRE WEATHER...
Issued at 320 PM CST Mon Dec 11 2017

Critical fire conditions appear to be underway across the Frenchman
basin this afternoon with several weather stations reporting
humidity below 20 percent and winds gusting to 30-40 mph. Patches of
cloud cover have developed and this will act to lessen the potential
for stronger wind gusts. It would appear gusts to 35-40 mph could
still develop until 3 or 4 pm MST.

Rain or snow liquid totals are expected to remain near or below 1/10
of an inch during the next 7 days.

Opportunities for range fire development occur Tuesday and Friday.
The area of concern both days is Southwest Nebraska, generally along
and south of Interstate 80 where humidity will fall to around 20
percent. Winds on both days should be light at 10 to 15 mph.
Otherwise, cool weather will cause humidity to remain above 25
percent across all of western and north central Nebraska.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 5 PM MST this afternoon for NEZ210.

&&

$$

SHORT TERM...Taylor
LONG TERM...CDC
AVIATION...Taylor
FIRE WEATHER...CDC



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