Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 240422 AAC

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
1122 PM CDT Sun Oct 23 2016

Issued at 306 PM CDT Sun Oct 23 2016

H5 hand analysis this morning had a continuation of the
broad ridging across the western and central portions of the CONUS.
Ridging aloft extended north into northern British Columbia and was
amplified by an upstream low off the coast of British Columbia.
The pattern across the western and central CONUS remains stagnant
this morning as little or no ht rises or falls were noted west of
the Mississippi river. Further east, a closed low was located over
southeastern Quebec with a trough of low pressure extending south
into New England. Ht. falls of 50 to 200 meters were from Maine
into the Canadian Maritimes. Further south, 50 to 100 meter rises
were noted over the Ohio Valley into the Carolinas. At the surface,
a cold front had passed through western and north central Nebraska
overnight and currently extended from southwestern Kansas into
northwestern Missouri. Skies were generally clear this afternoon
across the forecast area, with the exception of some mountain wave
cirrus across the southern third of the forecast area and some low
cloudiness trying to back into northeastern Nebraska from eastern
South Dakota. Afternoon temperatures as of 3 PM CDT ranged from 62
at Ainsworth to 67 at North Platte and Broken Bow.


Issued at 554 PM CDT Sun Oct 23 2016

The ARW...NMM....HRRR and RAP models show some fog by morning
along highway 281. This would form near sunrise and lift mid to
late morning. The RAP model sounding seems conceivable so a new
forecast is in place for this feature.


.SHORT TERM...(This evening through Monday)
Issued at 306 PM CDT Sun Oct 23 2016

Upper level ridging continues across the Rocky Mountain region as
high pressure slides slowly eastward across the upper Midwest.
Similar to the previous several days, quiet and dry conditions will
prevail. Clear skies tonight will allow temperatures to fall into
the mid to upper 30s across the forecast area.

On Monday, will continue to see dry weather, however, skies will
slowly become more cloudy throughout the day in advance of the
shortwave trough moving off the front ranges. This filtering in of
clouds from the west combined with cooler air filtering in on the
western side of the surface high will keep high temperatures across
the eastern forecast area a few degrees cooler than the last couple
days. Expect highs in the low to mid 60s across the eastern CWA.
Areas to the west across the eastern panhandle will still see highs
in the low 70s.

.LONG TERM...(Monday night through Sunday)
Issued at 306 PM CDT Sun Oct 23 2016

Monday night through Wednesday...In the mid range, the
main forecast challenges deal with the development of low clouds
and fog Monday night, along with the threat for precipitation
development Tuesday afternoon and Tuesday Night. For Monday night:
Thanks to increasing southeast winds, strong low level moisture
advection will commence across the forecast area, mainly east of the
Nebraska Panhandle. Dew points will increase into the middle and
upper 40s overnight which will lead to lows in the mid and upper 40s
Monday night-some 10 to 15 degrees above normal. Coverage of low
cloudiness will increase as well and as this cloudiness moves west,
fog will develop along the leading edge of the stratus. NAM12 BL RH
progs, as well as SREF fog probabilities indicate a high potential
for fog Monday night into Tuesday morning east of the panhandle and
west of a line from Valentine to Broken Bow. Ongoing forecast has
this mentioned right now and will be increasing coverage especially
over southwestern Nebraska based on the latest NAM12 and SREF visby
products which do indicate a high probability for fog development.
For Tuesday, fog and stratus will be slow to burn off from west to
east as a surface trough will track slowly from western into
central portions of the forecast area on Tuesday. The latest NAM12
is slightly faster with the track of the surface trough Tuesday
while the GFS20 is slower. This will limit any clearing along and
east of highway 83 Tuesday, leading to cooler temps in the eastern
forecast area given the expected cloud cover. Later in the
afternoon and evening, precipitation chances will increase in the
eastern forecast area, as a shortwave trough aloft, approaches the
surface trough. The models this morning are much weaker with the
capping inversion Tuesday afternoon/evening than yesterday`s runs,
which increases the confidence in thunderstorm development in the
east Tuesday night. Did make some changes to precipitation chances
in the east Tuesday afternoon/evening, mainly to draw pops further
west, however, they are still east of the highway 83 corridor.
Overnight, Tuesday night, the surface trough and upper level
disturbance will track slowly east-stalling across eastern
Nebraska. Boundary layer moisture will remain prevalent in the
northeastern forecast area, so low clouds are expected to persist
into Wednesday morning and possibly Wednesday afternoon in eastern
portions of the forecast area.

Wednesday Night through Sunday...Ridging will build back into the
central CONUS for Wednesday Night into Thursday Night. Temperatures
on Thursday may hit the lower 80s in far southwestern Nebraska as
H85 temps surge into the lower 20sC. This ridging will be short
lived however as a northern stream shortwave trough suppresses the
ridge-forcing a cold front into the forecast area later in the week.
There are some timing differences between the EC and GFS solutions
with their timing of this feature. The EC is 24 to 36 hours slower
with the front, so warm temperatures will carry over into Friday and
Saturday. Given the differences between the model solutions,
utilized the forecast blend for highs. As for lows, with a dry
airmass in place, blended lows were undercut 2 to 4 degrees to
better reflect the statistical guidance as well as climatology.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1122 PM CDT Sun Oct 23 2016

The ARW...NMM....HRRR and RAP models continue to show patchy fog
by morning along and east of highway 281. This would form near
sunrise and lift mid to late morning. Local IFR/LIFR is expected
with the fog and confidence is moderate for this event.

Otherwise VFR is expected all areas from 17z onward through 06z
Monday evening. Mid and high cloudiness will spread through
Western and North Central Nebraska. These clouds are associated
with an upper level disturbance moving through the Central




LONG TERM...Buttler
AVIATION...CDC is the U.S. government's official web portal to all federal, state and local government web resources and services.