Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 170544 AAB

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
1144 PM CST Thu Nov 16 2017

.SHORT TERM...(This evening through Friday)
Issued at 328 PM CST Thu Nov 16 2017

The main weather concerns through Friday afternoon concern strong
southerly winds this evening and an approaching cold front tomorrow.
A surface low developing near the Black Hills will slowly trek
southeast through the forecast period, dragging a cold front across
the Sandhills. The sfc front is accompanied by a mid-level
shortwave, adding to the forcing.

This evening, breezy south winds continue as the sfc pressure
gradient tightens across the state with the high slowly moving east.
As of 21z, MSLP ranged from 1002mb far NW to 1018mb far SE. H85 flow
is rather strong at 30-40 kts ahead of the low/mid level trough
approaching the panhandle. Winds relax overnight, especially across
SW Neb, allowing for some decoupling toward the pre-dawn hours.
Potential for some patchy fog exists near the GLD/GID borders as
noted by SREF and HRRR. Dew points hold nearly steady overnight with
some weak isentropic upglide. A prefrontal sfc trough works through
the area around 12z, switching winds to westerly and should quickly
dissipate the fog. Meanwhile, the actual front begins working into
far northern Neb. Low/mid level saturation is slow to occur except
for the panhandle/far NW, so held PoP off until after 00z Sat.

Temperature-wise, kept tonight`s lows fairly mild in the upper 30s
to lower 40s, which is on the high end or slightly above guidance.
In addition to the breezy south winds, an H85 thermal ridge crosses
the area preceding the trough. Temps reach 15C for much of the area
between 06z and 12z. Made little change to Friday highs in the south
(pre-frontal), but dropped slightly along/north of Hwy 20. High
cloud cover starts the day with ceilings gradually lowering through
the afternoon as the front comes through.

.LONG TERM...(Friday night through Thursday)
Issued at 328 PM CST Thu Nov 16 2017

Rain and snow chances during the next 7 days continue to revolve
around an event Friday evening. The NAM showed the the strongest
midlevel frontogenesis and produced the highest rain totals. The
forecast leans on the NAM for likely rain chances. A period of wet
snow is indicated in both the NAM and GFS but accumulations are
uncertain as the duration could be short-lived. The model consensus
of QPF plumes at North Platte, Broken Bow and Stockville suggested a
median QPF around 0.10 inches for this event. Just a few hundredths
was indicated at Valentine.

The temperature forecast continues to use is a model blend plus the
previous forecast plus a blend of bias corrected model and guidance
data. This strategy lowered temperatures Tuesday when 1030 mb arctic
high pressure will build through the upper Missouri basin and back
into wrn and ncntl Neb. This high will move quickly south and east
Wednesday and Thursday.

The upper level pattern is progressive for the next 7 days favoring
fast moving weather systems. The models are in good agreement
maintaining a deep upper level low across ern Siberia. This will
favor mild weather across Neb with low pressure systems tracking
well north of the area. A cool temperature forecast continues in
place Saturday as 1034 mb Pacific high pressure builds through the
Rockies. Warmer air returns Sunday and Monday and again Wednesday
and Thursday after Tuesday`s arctic high moves south and east.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1138 PM CST Thu Nov 16 2017

Mid and high clouds will continue to move east across western
Nebraska through the early morning. Southerly winds will continue
over night becoming north Friday morning. Scattered rain will
begin over western Nebraska Friday afternoon and become more
widespread after sunset.




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