Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 110944
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
344 AM CST Mon Dec 11 2017

.SYNOPSIS...
Issued at 344 AM CST Mon Dec 11 2017

H5 analysis from earlier this evening had a broad area of low
pressure extending from northern Quebec north into northeastern
Canada. Within this broad area of low pressure, individual low
pressure centers were located over Hudson Bay and northern Quebec.
A trough of low pressure extended south of this broad area of low
pressure, to the western Caribbean. West of this feature, ridging
extended from the Pacific Northwest, north into the Yukon of
Canada. Across the central CONUS, broad northwesterly flow was
present from the northern Rockies into the lower Missouri valley.
Within this northwesterly flow, a strong shortwave trough was
present over southern Saskatchewan. At the surface: Strong low
pressure was noted over far southeastern Manitoba with a warm
front extending south into swrn Minnesota and a cold front
extending west into Saskatchewan. A tight pressure gradient was
noted from the western Dakotas into Nebraska overnight. Winds were
already gusting in the 30 to 45 MPH range across the western
Dakotas overnight with some gusts appg 50 MPH in western South
Dakota. Further south, winds were generally lighter. Temperatures
as of 3 AM CST, ranged from 23 at North Platte to 47 at Ainsworth.

&&

.SHORT TERM...(Today and tonight)
Issued at 344 AM CST Mon Dec 11 2017

Winds and fire weather are the main weather concerns today.
Surface low pressure will track to the southeast across Minnesota
into the mid Mississippi valley today. Cold air advection and a
strong pressure gradient, will lead to gusty northwesterly winds
today across the forecast area. For the wind forecast, utilized
CONSALL for winds and tweaked these upward slightly to better
reflect NAM12 BUFKIT soundings for the forecast area. That being
said, widespread sustained winds of 25 to 35 MPH with gusts appg
50 MPH appear likely today. Winds should be strongest in the east
where cold air advection is strongest, as well as being in the
tightest sfc pressure gradient across the forecast area.
Temperatures will vary widely this afternoon as a cold front backs
into the forecast area from the east. That coupled with cloudy
skies, will lead to highs in the upper 30s to around 40 in the
east. Highs in the far southwest will be in the middle 50s as the
front will not back into these areas until late this afternoon.
Along with warm temperatures in the southwest this afternoon, very
dry air remains in place across the panhandle as evidenced by dew
points in the single digits to lower teens. The combination of
warm temps and low dew points will lead to minimum RH this
afternoon appg 15 percent in the far southwest. Given the very
windy conditions today, along with minimum RH around 17 percent,
decided to hoist a RED Flag warning for zone 210 for this
afternoon. Realize RH is marginal for a red flag warning this
afternoon, however, am more concerned about the strong winds. In
the northeastern forecast area this afternoon, the inherited
forecast had a slight chance mention for rain showers. Decided to
continue this in the current forecast given the degree of mid
level moisture and steep lapse rates. For tonight: High pressure
will build into western Nebraska overnight.

.LONG TERM...(Tuesday through Sunday)
Issued at 344 AM CST Mon Dec 11 2017

The latest long term models continue to show relatively dry and warm
conditions for the Sandhills region of Nebraska through the
extended.  The highly amplified western conus ridge will remain
largely in place through the end of the work week, but then begin to
show signs of breaking down with the approach of a trough next
weekend.  This highly amplified pattern will keep the high plains and
Sandhills in fast north northwesterly flow aloft through Thursday.
The northerly flow will usher a series of disturbances/waves across
the plains.  There is some disagreement between the GFS and EC in
regards to the available moisture with these waves.  The ECMWF
points to better moisture and thus provides for spotty QPF across
northern and north central Wednesday and again on Thursday.  The GFS
is much drier, keeping the Pacific moisture the EC is showing well
off to the west.  At this point we`re favoring the dry solution
given the pattern and recent dry period we`ve seen.  But we`re not
ready to completely pull all precipitation out of the forecast
across our north.  So will cap those chances at slight with minimal
qpf.  The GFS and EC are also at odds as to the strength and
moisture availability for the more significant trough next weekend.
It`s too early to make the call, but again as it seems now, northern
Nebraska has the best shot at seeing any precipitation and if that
occurs, it would be light.  Otherwise the active northerly flow will
keep winds breezy Wednesday and Thursday, but the guidance suggests
non-critical RHs save for possibly our far southwest.  Regardless
it`s been over 2 months since any appreciable moisture has fallen
for many areas.  Large range fire spread will be a concern when
there`s wind in the forecast, we need some moisture.  Highs in the
40s and 50s will give way to highs in the upper 30s and 40s on
Thursday behind a front, but otherwise temperatures will continue to
be above to well above normal through the extended.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1122 PM CST Sun Dec 10 2017

A cold front will move across western Nebraska early Monday
morning with winds being the main concern for aviation. Strongest
northwest winds will begin between KVTN and KONL along with some
light rain and snow mixed Monday morning. Strong northwest winds
will spread over all of western Nebraska through the day on
Monday.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM this morning to 5 PM MST this
afternoon for NEZ210.

&&

$$

SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Jacobs
AVIATION...Power



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