Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 150520

Area Forecast Discussion
National Weather Service North Platte NE
1120 PM CST Tue Feb 14 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 250 PM CST Tue Feb 14 2017

Light westerly downsloping winds will rule overnight as the
pressure gradient relaxes from west to east. Under clear skies,
a good radiational cooling event is forecast with the latest
guidance indicating lower to mid 20s across much of the CWA by
dawn. The downsloping winds will back to southwest and increase
slightly through the afternoon as a lee trough develops over the
high plains. The downsloping component will combine with strong
WAA to promote a strong warm up Wednesday afternoon. Highs will
run some 10-12 degrees Fahrenheit warmer, generally in the lower
to mid 60s. We did consider the dense snowpack across our northern
zones where highs will still rise into the mid to upper 50s.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 250 PM CST Tue Feb 14 2017

The primary weather highlights in the long term period continue to
revolve around unseasonably warm temperatures Thursday through the
weekend and possible precipitation chances Sunday-Monday. Main
concerns are dry conditions/lower humidity Thursday and Friday
given the warm temperatures, downsloping winds, and low moisture
in the lower troposphere. The region will see highs largely 25
degrees above normal Thursday and approaching 30 degrees above at
some locations. Temperatures then trend slightly cooler Friday
into the weekend.

Large scale pattern will remain amplified and will feature a ridge
initially over Southwest US into the Northern High Plains at the
start of the period. The upper level ridge will continue to
dominate the sensible weather across western and north central
NEB early on in the long term. The ridge slides eastward to the
Northern Plains Thursday then to the Upper Mississippi Valley by
late Friday. The ridge will undergo some deamplification as it
moves eastward Thursday and Friday as a shortwave trough lifts
northeast into the Northern Plains. Though east of the shortwave
trough there will be height rises as ridging occurs Friday over
the northern Intermountain West. As mentioned previously, dry
conditions and unseasonably warm temperatures are expected as
westerly downsloping flow prevails into Friday. Above average
confidence in the forecast of well above normal temperatures
occurring Thursday and across portions of north central NEB
Friday. Deterministic guidance remains in fair agreement with
their anomalously warm 850 temperatures aloft with forecast values
exceeding those over the 90% moving average for these dates based
on the SPC sounding climatology for LBF. Furthermore, a favorable
signal remains present in the NAEFS mean 850 hPa temperature
forecast with the NAEFS forecast placing significantly above
climatology across NEB.

Looking ahead beyond Friday, generally quiet sensible weather is
anticipated through Sunday. Guidance continued the trend seen the
last two days of decreasing precipitation chances this weekend
with chances now confined to the Sunday Night-Monday time period.
Another upper level trough is expected to come onshore to the West
Coast Saturday. This upper trough is anticipated to affect the
region and bring increased precipitation chances to the area
Sunday Night-Monday. Deterministic guidance appear to be in fair
agreement with said trough moving quickly in the amplified flow.
The upper trough is expect to move to Sonora Mexico-Central Great
Basin-northern Intermountain West by Sunday then to the Central
and Northern Plains by Monday. Ahead of the disturbance, moisture
is expected to be sufficient with low-level moisture expected to
be transported into the region from the Gulf Sunday into Monday,
more so across north central NEB. A surface low pressure system is
expected to develop and be positioned in the Northern Plains or
in the northern Southern Plains before lifting out of the area
late Monday. While there remain differences in amplitude and phase
with the large scale pattern, slight chance-chance PoPs appear
reasonable in this time period.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1120 PM CST Tue Feb 14 2017

VFR conditions will persist the next 24 hours across western
Nebraska. Winds will be light westerly overnight into Wednesday
morning, then southwest with gusts up to 15 kts in the afternoon.
Skies will range from skc to few250.


Issued at 250 PM CST Tue Feb 14 2017

Abnormally warm high temperatures will combine with a dry airmass
to increase the threat of large range fire spread Wednesday and
Thursday afternoon. The latest guidance has trended warmer with
the airmass, now promoting highs in the 60s on Wednesday with
upper 60s to lower 70s possible for Thursday. A limiting factor to
large range fire growth is that despite the downsloping
(westerly) component of the wind, it is forecast to remain less
than 20 mph with most locations expected at 15 mph or less. In
addition, a fairly significant snow pack, or at least partial
drifts remain over much of our Sandhills and points north. I80 and
south, snow is largely absent. Will continue to closely monitor
over the coming days/weeks if the dry and warm conditions
continue. It won`t take much before we lose the protection of our
ever dwindling snowpack, but for now, we are not anticipating the
need of fire weather headlines.




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