Area Forecast Discussion
Issued by NWS North Platte, NE
FXUS63 KLBF 302333 AAA
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
533 PM CST Wed Nov 30 2016
.SHORT TERM...(This evening through Thursday)
Issued at 327 PM CST Wed Nov 30 2016
The large upper trough that has been nearly stationary over the
Dakotas and Minnesota over the last 72 hours will finally shift
eastward tonight toward the Great Lakes region. This will bring an
end to scattered flurries/light snow that we have seen through the
last couple days. Gusty winds will also relax after dark as the
local surface pressure gradient weakens. Expecting temperatures
tonight to fall off into the teens and 20s, with the warmer readings
in north central Nebraska where overcast skies will hold through
most of the night. A few lows in single digits are possible in the
Pine Ridge area of northwest Nebraska due to clear skies, fresh
snow cover, and light drainage winds.
An area of high pressure slides south into the forecast area for
Thursday under zonal flow aloft. This will lead to a quiet day with
light northwest winds. Most of western Nebraska will see more
sunshine as drier air pushes into the Central Plains, although the
stratus clouds will be stubborn to vacate north central Nebraska as
moisture continues to wrap around the departing upper level low. H85
temperatures remain relatively unchanged, so still expecting near to
below average high temperatures over the CWA.
.LONG TERM...(Thursday night through Wednesday)
Issued at 327 PM CST Wed Nov 30 2016
Thursday night through Saturday...the model consensus has backed off
on the warming trend expected to develop Saturday such that highs
would only be a few degrees above normal. The problem appears to be
mid and high clouds associated with a storm system moving through
the desert Southwest. This cloudiness would most likely affect
temperatures across Southwest Nebraska.
Bias correction continues to indicate lows in the teens and 20s
which might be too cold given the expected cloud cover. Highs Friday
and Saturday rise into the 30s and 40s.
Winds are light in this forecast time frame. No significant high or
low pressure systems will be operating to produce strong winds. Wind
speeds should be 10 mph or less until Saturday. On Saturday a weak
disturbance will be moving through the Nrn Plains and Canada setting
up southwest winds near 15 mph in the afternoon. The forecast is dry.
Saturday night through Wednesday...weak thermal ridge develops
Sunday and Monday. The models are a bit slower with the timing of an
arctic cold front. The latest solns show just a portion of a 1050mb
high across northern Canada dropping through the High plains
Tuesday. The model consensus shows light snow developing with the
passage of the arctic front. The GFS is 6 to 12 hours faster with
the frontal passage than the ECM.
The GFS indicates a brief period of freezing drizzle Monday night as
the front moves through north central Nebraska. Highs Monday may
still rise into the 40s...especially if the slower ECM verifies. The
latest guidance indicates highs in the 20s to around 30 Tuesday and
teens and 20s Wednesday which could translate to wind chill readings
of 0F to -15F Wednesday morning if lows fall into the single
digits. H850mb temperatures fall to -15C to -20C.
A second area of snow may develop Tuesday or perhaps Tuesday night.
The GFS is fast once again beginning snow Tuesday morning while the
ECM shows snow late Tuesday afternoon. This is related to upper
level dynamics which are faster in the GFS. Both models indicate
powerful dynamics moving through the srn Rockies. The experimental
FIM is similar.
The forecast is for a 30 to 40 POP Tuesday-Tuesday night and note
there has been a lot of wobbling with the storm track for this
system which could be related to a lead short wave moving through
the Nrn Plains Monday which is the driver for the arctic cold front.
The stronger model solns send the cold air and focus for snow
farther south. The best soln for snow is a weak lead short wave. The
latest forecast from WPC suggests around 0.25 inches of QPF across
Srn Neb with lighter amounts north. This is also close to the
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 530 PM CST Wed Nov 30 2016
Northwest winds will become light and variable tonight. Stratus
east of a line from LIEN to KBBW will continue to move east over
night with mvfr ceilings at KVTN lifting into VFR categories early
Thursday morning. VFR categories will continue to the west and
southwest through Thursday afternoon.