Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 182052

Area Forecast Discussion
National Weather Service North Platte NE
352 PM CDT Tue Oct 18 2016

.SHORT TERM...(This evening through Wednesday)
Issued at 345 PM CDT Tue Oct 18 2016

The main challenge in the short-term period was precipitation
chances tonight through tomorrow; otherwise, overall sensible
weather concerns revolved around temperatures and said chances.
Latest satellite imagery and surface plot shows few-scattered mid
clouds with bases around 10 kft with broken-overcast across the
southern NEB Panhandle. Very dry air in place in the boundary
layer with dew point depressions near or greater than 35 degrees
across much of western Nebraska.

Elongated broad high pressure aloft extends across the Southern
Plains to Mid Atlantic at 500 hPa and across the Pacific offshore
near far southern CA to northern Mexico at the beginning of the
period. Elsewhere, broad low amplitude westerly flow is present
across the Western CONUS to Central Rockies to the Lower Great
Lakes. A disturbance and associated vort max in the embedded flow
will move eastward across the Central Rockies into the NE
Panhandle tonight. Wherein mid-level frontogenesis is anticipated
to increase and become positioned across western NE and the
western NEB Sandhills. The trough then continues to advance
eastward across the Central Plains tomorrow. Overall, the pattern
aloft becomes more amplified with a ridge building across the
Intermountain West into the Northern Rockies Wednesday. Mid-level
forcing then advances eastward early tomorrow into tomorrow
evening across north central NE.

Deterministic guidance are in fair agreement with QPF and
placement, however, the latest 12Z cycle of the GFS has it`s
placement a bit farther south compared to the 12Z NAM12. Of which,
appears this could be attributable to differences in location of
forcing. In terms of thermodynamic environment, precipitation type
is expected to be all rain as a considerable warm layer would have
to be overcome near the surface, with a depth exceeding 2500 ft
AGL based on soundings. Further, 850 hPa temperatures stay more or
less above 5C across western and north central NE overnight.
Tomorrow, ptype is expected to be all rain as well. Further,
precipitation chances will persist through the day also. The
combination of a weak surface cold front advancing southward
tomorrow, showers, and ample sky cover will result in tomorrow
being one of the cooler days this work week. Highs are forecast
to be mainly mid to upper 50s, four to six degrees below their
seasonal normal values.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 345 PM CDT Tue Oct 18 2016

Tomorrow Night through Friday: Pattern aloft becomes more
progressive in this period. Weak mid-level height rises spread
across western and north central NEB tomorrow night followed by
more modest height rises on Thursday. Wherein the 500 hPa ridge
will be over the Intermountain West into the western Northern
Plains by Thursday. While slight chances to chances will be
present across the local forecast area to start (Wednesday
Evening) attributable to a disturbance aloft, chances will then
taper off through early Thursday morning. A drier air mass will
then take hold under the building ridge. Despite clearing skies
Thursday, cool air entrenched across the area will result in high
temperatures staying cooler than normal (and similar to Wednesday)
with highs in the mid to upper 50s.

500 hpa ridge then continues to build eastward and will be
centered roughly near the Southern to Northern High Plains
Friday. The building ridge aloft will then begin a warming trend
with dry conditions expected across western and north central NEB.
Wherein Friday low-level temperatures will increase with 850 hPa
temperatures ranging from about 11-15 C. Highs Friday are forecast
to be in the lower 70s from southwest NEB to mid-upper 60s in
north central NEB.

Friday Night through Tuesday: The upper level ridge will continue
to influence the sensible weather across western and north central
NEB this weekend and Monday. Ultimately, warm and dry conditions
are expected to continue through this portion of the period. The
local forecast area will see above normal temperatures persisting
through Monday wherein highs are forecast 8-14 degrees above
normal. This will go in tandem with dry conditions with no
precipitation forecast.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1240 PM CDT Tue Oct 18 2016

Main concern will be the threat for rain showers overnight into
early morning. Showers are expected to begin after 06z for KVTN
and after 10z for KLBF terminals. There is a possibility showers
could linger after 12z across north central Nebraska...but
confidence is not high at the moment so have left the mention of
rain after 12z out of the TAF for KVTN. Precipitation type should
be all rain. Skies will be mostly clear remainder of the day today
and will then become broken to overcast this evening, then
continuing through tomorrow. Low-end VFR ceilings expected with
precipitation overnight/tomorrow.




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