FXUS63 KLBF 192347

Area Forecast Discussion
National Weather Service North Platte NE
647 PM CDT Mon Aug 19 2019

.SHORT TERM...(This evening through Tuesday night)
Issued at 313 PM CDT Mon Aug 19 2019

South to southeast winds have developed on the backside of a surface
high that continues to move off to the east across Iowa. A
moist/humid airmass has quickly move back into the area, with dew
points climbing into lower and mid 70s this afternoon. Despite
strong instability and decent shear, a very strong capping inversion
in place this afternoon/evening should keep thunderstorm development
in check. Models have hinted though at an isolated storm or two
developing near a dry line from Sidney southward into northeast CO.
These storms attempt to move eastward, but the lack of much forcing
combined with the strong cap should keep them from getting very far.
Otherwise expect a warm night with the increased humidity, with
lows in the 60s to near 70F.

Severe weather parameters for late Tuesday afternoon into Tuesday
evening look good, but actual storm development is somewhat
conditional. A warm front will be located across northern KS or far
southern NE to the east of a surface low which will be located
across northeast CO. North of this front low-level Gulf moisture
will pool with dew points in the 70s as far west as Ogallala.
Temperatures will warm into the upper 80s to lower 90s by afternoon,
and these warm temperatures will combine with very steep mid-level
lapse rates and the moist airmass to produce strong to extreme
surface based CAPE by late Tuesday afternoon. Flow aloft is modest,
with speeds at H5 only around 15 to 25 kt, however low-level
easterly flow will increase the overall effective shear. Of concern
will be a stout capping inversion that will be in place. In addition
the overall forcing is weak, so surface based thunderstorm
development across southern/southwest NE near the warm front is
uncertain. The more favored/likely scenario would be for surface
based storms to develop very late Tuesday afternoon to the northeast
of the surface low across the central and southern Panhandle.
Persistent upslope flow will add extra upward motion to help
overcome the cap in this area. Initially large hail will be a
concern from these storms due to the very steep mid-lapse rates,
then later in the evening as the low-level jet increases, the storms
should grow upscale and track east roughly along the I-80 corridor
to the north of the warm front. Some threat for large hail may
continue, but damaging winds would also become a concern along with
locally heavy rainfall.

.LONG TERM...(Wednesday through Monday)
Issued at 313 PM CDT Mon Aug 19 2019

The warm front will remain across the area through the day
Wednesday. Appears a weak shortwave will cross the area within
westerly flow aloft. This will help maintain lift, and with the
front in the area anticipate lots of cloud cover and at least
scattered showers and thunderstorms. The easterly low-level moist
flow combined with cloud cover will likely hold highs in the 70s

Heights will rise due to ridging aloft building northward late this
week into the weekend. With the ridging building northward
through the Rockies expect northwest flow aloft to dominate across
our area on the eastern periphery of the ridge. Any weak
perturbation embedded within this flow could spark an isolated
thunderstorm or two. Otherwise look for highs to climb from the
70s Thursday to 80s for the weekend.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 646 PM CDT Mon Aug 19 2019

High cloudiness will continue to stream across western and north
central Nebraska overnight with scattered ceilings expected around
25000 FT AGL. Some low cloudiness may develop at the KLBF terminal
overnight with ceilings as low as 1500 FT AGL. These low ceilings
will be centered during the 11z to 15z time frame Tuesday.




LONG TERM...Taylor
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