Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 181144

Area Forecast Discussion
National Weather Service North Platte NE
544 AM CST Sat Feb 18 2017

.SHORT TERM...(Today and tonight)
Issued at 359 AM CST Sat Feb 18 2017

Minimal sensible weather concerns across western and north central
NEB the next 24 hours. The weather highlights today and tomorrow
include: well above normal high and low temperatures (15 to 25
degrees above normal); light breezes in the afternoon (strongest
over northwest NEB), and patchy fog late Saturday Night/Sunday
morning. Partly sunny skies and unseasonably warm temperatures, in
the low to mid 60s, will prevail today across the region followed by
mild lows overnight.

Latest analysis and surface plot shows surface high pressure over
central NEB. The latest IR satellite imagery shows high clouds
upstream over CO streaming into the NEB Panhandle and western NEB.
Latest WV imagery shows a deep mid-level trough moving onshore into
the West Coast with southwest moist onshore flow impacting Southwest
US. Elsewhere, a strong positive PV anomaly is tracking east through
the Arrowhead Region and a closed low over the ArkLaTex region is
lifting into the Tennessee Valley.

The large scale pattern will feature weak 500 hPa height rises over
the region today as a ridge builds northward into the far eastern
Central Plains and the Middle Mississippi Valley. Meanwhile, the
aforementioned Pacific upper trough will move onshore into the West
Coast US and Baja California by this afternoon. Slightly cooler
highs today, albeit still well above normal, given slightly cooler
air mass in place after yesterday`s weak frontal passage. 850 hPa
temperatures about 8-10 C, coldest in far north central NEB. Partly
to mostly sunny skies are anticipated today as high clouds stream in
from the southwest. Light breezes are expected to develop this
afternoon, strongest breezes and gusts in northwest NEB where there
will be good potential for upper level winds to mix down to the
surface. In northwest NEB wind gusts up to 20 kts possible given
mean mixed layer winds as seen in BUFKIT soundings. The combination
of the mild air mass in place, elevated winds and increasing
moisture overnight will lead to mild lows Saturday Night. In
addition, there will be the potential for fog in the southeast half
of the local forecast area.

.LONG TERM...(Sunday through Friday)
Issued at 359 AM CST Sat Feb 18 2017

Sunday through Monday night...main concerns during this forecast
period is the potential for fog Sunday morning and thunderstorm
chances Sunday night into Monday. Have added patchy fog through mid
morning Sunday for areas south and east of a line from O`Neill to
Madrid. As for Sunday night current thinking is that the best
potential for thunderstorms will be after midnight when the
potential vorticity max will enter the region helping to steepen
lapse rates. We are day2 outlooked for general thunderstorms from this time it doesn`t look like the ingredients for
thunderstorms to reach severe potential are in place.

Tuesday through Friday night...Tuesday through Wednesday
temperatures will be above normal with a cool down occurring
Thursday. The main concern this period is the wind potential on
Friday along with precipitation chances. Have increased the winds
slightly to account for tight pressure gradients in association with
the surface low that will be moving across the region...didn`t want
to drastically increase as confidence is low on the track of the
system as it is still several days out. This is also true for the
precipitation potential, as the system is still more than 6 days out
there is a lot of uncertainty with the track of the system and this time it looks like any precipitation that
does occur would be in the form of snow.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 544 AM CST Sat Feb 18 2017

VFR conditions expected the next 24 hours across much of western
and north central NEB. Latest satellite imagery shows high clouds
streaming across the local forecast area. Surface high pressure
currently over central NEB will move eastward to MN and IA today
prompting southerly winds to increase. Strongest winds over
northwest NEB and the far northern Sandhills where gusts up to 20
kts are expected. Southerly winds will stay elevated overnight,
mainly between 5 and 10 kts. Increasing low-level moisture
overnight will promote the potential patchy fog across portions
of north central and southwest NEB late tonight-Sunday morning.

Looking ahead, dry conditions and breezy southerly winds are
expected tomorrow. This will be followed by increased chances for
rain showers Sunday Evening through early Monday afternoon. Also,
a few thunderstorms will be possible Sunday night, however, no
severe thunderstorms are expected.




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