Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
FXUS63 KLBF 141802

Area Forecast Discussion
National Weather Service North Platte NE
102 PM CDT Fri Oct 14 2016

.SHORT TERM...(Today and tonight)
Issued at 355 AM CDT Fri Oct 14 2016

The main challenges in the short-term period were winds and sky
cover. The main concerns in the short-term are elevated-critical
fire weather conditions across portions of the eastern Panhandle and
western NEB Sandhills where a Red Flag Warning is in place for
portions of fire weather zone 204 today. Added this package into the
Red Flag Warning was fire weather zone 208, west of Valentine. For
details on the fire weather situation, please see the fire weather
discussion. Otherwise, a moderate-strong breezy, dry, and
unseasonably warm day is in store for western and north central NEB.
Wherein highs will be as much as 20 degrees above seasonal normals
in the eastern NEB Panhandle (mid to upper 80s) to 15 degrees above
in parts of north central NEB (mid 70s to low 80s).

Aloft, quasi-zonal flow at 500 hPa to start the forecast period will
transition and become more southwesterly beginning in the evening
with neutral to weak heights falls expected over the CWA. Southwest
flow aloft and weak height falls then continue overnight while a
weak disturbance embedded in the 500 hPa flow moves east across
western NEB late tonight. Meanwhile, there will be a deepening lee
side trough today across the central High Plains. Low-level winds
at 700 and 850 hPa will turn more southwesterly by late morning.
This will promote drying conditions and warm temperatures as
downsloping winds prevail along with warm air at low-levels as it
overspreads across western and north central NEB. 850 hPa
temperatures are expected to be 20-25 C, warmest in the eastern
NEB Panhandle. This and the overall environment should support
highs as much as 20 degrees above seasonal normal values today in
the eastern NEB Panhandle.

Also, will see breezy conditions today with gusts to 30 mph
expected, and exceeding at times possibly in portions of the NEB
Sandhills. Very good potential for upper level winds to mix down to
the surface with decent momentum transfer expected today as a well-
mixed boundary layer is expected to be established across the
forecast area. Notably, model soundings denote mean mixed-layer
winds exceeding 25 kts at sites across western NE and parts of the
NEB Sandhills  this seem very reasonable. Of note, scattered clouds
are expected to start pushing into western NEB with bases about
15,000 ft, thus by early evening scattered-broken clouds are
expected across western NEB. Winds should start to lessen in the
evening, becoming 5-10 kts in the Sandhills by the early morning.
This will coincide with increasing sky cover across north central
NEB tonight. The combination of warm air, elevated light winds, and
sky cover should result in unseasonably warm low temperatures from
mid-upper 40s in the NEB Panhandle to mid 50s in north central

.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CDT Fri Oct 14 2016

12z Saturday and beyond.  Southerly flow in advance of a frontal
boundary will work in conjunction southwest flow in the mid and
upper levels to support abnormally warm temperatures across the high
plains and adjacent Sandhills this weekend and early next week.  The
latest guidance supports highs in the 70s and 80s during the
afternoon hours with the latest bias corrected data indicating the
potential of lower to mid 80s for highs Sunday and Monday afternoon.
Pacific moisture in the upper levels may be sufficient to produce
some cloudiness this weekend, so will keep temperatures on the lower
and middle range versus the higher side of the envelope.  The warm
temperatures will allow relative humidity to fall below 25% Sunday
and Monday afternoon for location generally west of a VTN to TIF to
LBF line with the possibility of sub 20% west of a IML to OGA to IEN
line. Light winds are generally forecast as the latest guidance
suggests peak gusts of 20 mph or less Sunday.  Monday may be
concerning in terms of fire weather as a strong Pacific cold front
is progged to arrive across our western zones in the late afternoon.
West winds of 25 mph with gusts in excess of 35 mph are possible.
CONSMOS seems to have a good handle on the gust potential during the
afternoon, thus the forecast was trended in that way. Temperatures
will cool behind the front allowing highs Tuesday through Thursday
to return near seasonal norms.  Accompanying the front will be a
shortwave which rapidly progresses northeast across the Dakotas
Monday evening. Favorable upper dynamics and forcing for qpf with
the system will largely be north of the CWA.  Wednesday a secondary
shortwave will dig across the rockies and east across the central
and southern plains.  The long range models came in tonight with a
better precipitation signal for the cwa, but at that only isolated
or scattered showers would be expected with temperatures supportive
of liquid qpf.  Rainfall amounts would be minimal as moisture will
be scarce with all the fronts blocking much of the return moisture
east of the area.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1258 PM CDT Fri Oct 14 2016

High clouds continue to stream across the area and expect this
trend to continue the next 24 hours. Gusty south/southwest winds
today with decoupling to cause winds to diminish overnight,
especially in the river valley and the KLBF terminal. Models keep
winds aloft on the gusty side and have included wind shear in the
KLBF terminal. KVTN will be close but winds stay up a little more
so have kept out of the forecast for now. Otherwise weak trough
pushes across the area early in the morning with northwest winds
to increase.


Issued at 355 AM CDT Fri Oct 14 2016

Elevated to critical fire weather conditions are expected across
much of fire weather zones 204 and the western-fourth of fire
weather zone 208 (west of Valentine). Wherein gusty winds between 25-
30 mph is expected to coincide with RH in the teens (near/below 15%)
as a lee side trough deepens over the central High Plains today.
Downsloping winds and warm temperatures aloft at low-levels will
promote drying and above-normal high temperatures across the
aforementioned areas. Per the earlier discussion, fuels are
receptive for fire so there is potential for large range fire spread
to be possible in fire weather zone 204 and fire weather zone 208
east of Valentine. Added fire weather zone 208 this package as
increased confidence that the area will see dry conditions in tandem
with frequent wind gusts in excess of 25 mph. Elsewhere, we will see
very low humidity in portions of fire weather zones 210 and 206,
however, at this time do not think winds will be sufficiently high
to support critical fire weather conditions. Locally, may see
portions of fire weather zone 206 in the northwest quad that
approach 15 percent with winds near 25 mph, however, this is
anticipated to be brief.


Red Flag Warning until 7 PM CDT /6 PM MDT/ this evening for



LONG TERM...Jacobs
FIRE WEATHER...ET is the U.S. government's official web portal to all federal, state and local government web resources and services.