Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 211121 AAA

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
621 AM CDT Wed Jun 21 2017

.SHORT TERM...(Today and tonight)
Issued at 340 AM CDT Wed Jun 21 2017

The ongoing MCS across Scntl SD may brush Ncntl Neb for a few hours
this morning. This system should cast a boundary through Holt and
Custer County which would be the focus for isolated severe storm
development this afternoon and this evening. Wind damage is the
primary concern as the shear is weak with 500mb winds near 30kt.

The temperature forecast uses the HRRR EXP model exclusively as it
has been the best performing model since Monday. The combination of
H700mb temperatures of 15-16C...northwest winds...deep mixing and
summer solstice heating is expected to send temps into the low 100s
this afternoon.

There is a chance the dew point forecast of 60+F is too high along
and east of a line from Hayes Center to North Platte...Broken Bow to
Bartlett. If it verifies then heat indices will rise to over 100F.
No heat advisory will be issued for this forecast, the vertical
mixing will be very strong which could displace the moisture. A
special weather statement will be issued instead.

Blended guidance plus bias correction produces lows in the upper 50s
to mid 60s tonight. Cooler H850mb air will be backing through the
forecast area.

.LONG TERM...(Thursday through Tuesday)
Issued at 340 AM CDT Wed Jun 21 2017

12z Thursday and beyond.  Upper level low north of the Canadian
border will force a cold front across the Sandhills on Thursday. The
front is now shown to arrive earlier and continue south well into
Kansas before stalling out.  The latest projections now favor the
better thunderstorm chances south of the forecast area, as much of
the cwa will be under the influence of post-frontal stable
conditions.  The latest SPC Day Two outlook now indicates just a
sliver of slight chance along our southern border, with marginal
expanding from southwest to north central Nebraska.  The upper
trough will swing through the northern plains on Friday with much
cooler air behind it.  Widespread highs in the 70s appear likely,
with just 60s for Saturday.  Enough forcing may remain for some
light rainshowers Saturday morning and afternoon.  The activity
seems to focus across southwest Nebraska with the newest model runs.
The atmosphere is shown to be weakly unstable, so showers and garden
variety storms would be all that is expected. Temperatures slowly
moderate Sunday and early next week as the long range models suggest
a building mid-level ridge over the southwest and high plains.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 620 AM CDT Wed Jun 21 2017

VFR is generally expected all areas today and tonight.

The isolated showers east of highway 83 should either move east or
dissipate 13-15z this morning.

Isolated severe thunderstorms are possible 21z-03z this afternoon
and evening generally along and east of a line from Stockville to
Broken Bow to Oneill.

Some models generate thunderstorms off the Laramie and Front
Ranges this afternoon. This activity is expected to weaken as it
moves east. Isolated showers may enter Wrn Nebraska 04z-08z




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