Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 201145

Area Forecast Discussion
National Weather Service North Platte NE
645 AM CDT Fri Oct 20 2017

.SHORT TERM...(Today and tonight)
Issued at 400 AM CDT Fri Oct 20 2017

Latest satellite imagery shows a mix of mid and high level clouds
streaming northward over western and north central NEB. Water
vapor imagery shows cyclonic flow across California spreading east
to the Northern and Central Plains with an amplified trough
moving onshore the West Coast. Highs will be similar to a few
degrees cooler than yesterday with values 14-18 degrees above
seasonal normal values  largely mid-upper 70s.

Decent moisture delivery today via Gulf moisture transport with
surface dewpoints rising to the 50s outside extreme western NEB
with mid 50s expected in portions of north central NEB. Large
scale trough moves east to the Northern Rockies to Central Great
Basin-Central Rockies today. Meanwhile, modest 500 hPa ht falls
persist today and tonight overhead. Increasing southerly breezes
today as surface trough sharpens with breezy winds east of the
trough, outside the eastern Panhandle and far southwest NEB.
Strongest gusts across north central NEB peaking largely 35 MPH.
Favorable setup for momentum transfer with upper level winds
mixing down. Mean mixed-layer winds of 25+ kts covering an
appreciable portion of the forecast area outside the
aforementioned areas near the trough. Overnight, a surface cold
front will advance east across the area mid-late evening through
early morning tomorrow. Meanwhile, winds stay elevated overnight.
Increasing northwest winds are expected over the western-third of
the local forecast area through the small hours. Increased
precipitation chances largely after midnight with the best chances
over northeast NEB and the northeast Panhandle. Of which,
instability sufficient for mention of thunder in portions of north
central NEB.

.LONG TERM...(Saturday through Thursday)
Issued at 400 AM CDT Fri Oct 20 2017

More wind expected Saturday in the wake of the cold front. NAM
indicates 30 to 40 kt H85 winds behind the front during the morning
hours, gradually weakening during the afternoon. Well mixed boundary
layer and CAA should lead to breezy or locally windy conditions for
at least the first half of the day. Showers are also possible,
especially across northwest Nebraska during the morning, where
favorable jet dynamics will be located. Have increased pops a bit,
as soundings indicate enough moisture to allow any precipitation to
make it to the surface. Some lingering mid level instability across
far eastern north central Nebraska, where a few rumbles of thunder
are possible with any shower during the morning.

Skies quickly clear and winds rapidly decouple Saturday night. Drier
air in place, along with the clear calm conditions will allow for a
chilly night as lows drop into the lower 30s. Could be some isolated
upper 20s in river valleys etc.

Downslope warming winds expected Sunday with highs climbing back
into the upper 60s to near 70 degrees. Then cooler Monday as a cold
front moves across the region. A secondary cold front will usher in
even cooler air Tuesday with highs only in the 50s. A brief warm up
Wednesday followed by a strong cold front and much cooler again for
Thursday. Not much chance for precipitation with northwest to north
flow aloft due to deep upper trough across the Great Lakes region.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 625 AM CDT Fri Oct 20 2017

Latest satellite and surface plot shows mid and high level clouds
streaming northward across western and north central NEB. Main
concerns revolve around winds this TAF package. There is potential
again for LLWS affecting some terminals tonight, along with
chances for precip late tonight onward.

Southerly winds increasing this morning with breezy conditions
continuing through the afternoon. The strongest wind gusts will
be outside the eastern Panhandle and far southwest NEB wherein
gusts exceeding 25 MPH will be common. Winds lessen some this
evening but remain elevated. An advancing cold front tonight-early
morning tomorrow will prompt winds to shift and become
northwesterly. LLWS conditions develop tonight towards central
NEB on east and will affect the KLBF terminal. Winds at the top of
the wind shear layer forecast about 45 kts with an upper height
of about 1500 ft AGL. Otherwise, increased precipitation chances
late tonight with the best chances over northeast NEB and the
northeast Panhandle. Still some uncertainty with respect to
possible impacts at KVTN thus will continue to fine-tune.




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