Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 122333

Area Forecast Discussion
National Weather Service Topeka KS
533 PM CST Mon Feb 12 2018

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday)
Issued at 248 PM CST Mon Feb 12 2018

20Z water vapor imagery shows a closed low over northern NV with
an upper trough over Hudson Bay. At the surface, ridging remained
over the Great plains with the high centered over the upper
Midwest. Although the ridge is weakening as obs indicate pressure
falls along the lee of the Rockies.

For tonight and Tuesday, dry weather is expected to continue.
Models show some weak disturbances within the southwest flow
aloft. However limited moisture should preclude any meaningful
chances for precip. With the pressure falls out west, there is
expected to be enough of a pressure gradient force to keep winds
up through the night. This with some mid and high clouds should
keep overnight lows in the upper teens and lower 20s. Southerly
winds through the day Tuesday are expected to bring warmer air
into the region with highs reaching around 50.

.LONG TERM...(Tuesday night through Monday)
Issued at 248 PM CST Mon Feb 12 2018

The warming trend is likely to continue on Wednesday as models
warm 925mb temps to around +15C. forecast soundings support good
mixing of the boundary layer so highs in the mid and upper 60s
looks on track. The exception may be along the NEB state line
where snow remains on the ground. This could keep highs in the
upper 50s.

Models have become less aggressive with QPF on Thursday. Forcing
for precip could be better as energy from the southwest is progged
to shear out. Additionally models have tended to keep the deeper
moisture just south of the forecast area limiting available
moisture as the front pushes south late in the day. With much of
the guidance trending with little or no QPF, have lowered POPs
for Thursday and Thursday night. The front should cool temps down
for Friday as a Canadian high moves south. This looks to be short
lived as the synoptic pattern favors westerly flow aloft and
pushes the surface ridge east fairly quickly. So temps are
expected to moderate back into the 50s for the weekend.

There are some small POPs in the forecast for late Sunday and
Monday as energy digs into the southwest once again. There are
some indications for weak energy to kick out from the southwest as
another cold front pushes south. Moisture will once again be a
deciding factor on precip chances. The GFS suggests there could be
some marginal moisture advection Sunday night before the front
gets into the area. But again progs for large scale forcing are
not well organized with mainly sheared out waves within the flow.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 528 PM CST Mon Feb 12 2018

Expect moderate low-level windshear to develop later this evening
across the terminals and extend through the early morning hours
of Tuesday. The low-level windshear will be in the 25 to 30 KT
range from the surface up to 1500 feet. if winds become lighter at
the surface then the terminals may have over 30 KTS of low-level
wind shear at times. Otherwise, expect VFR conditions.




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