Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 130551

Area Forecast Discussion
National Weather Service Topeka KS
1151 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 06Z TAFS through 06Z Tuesday night)
Issued at 1137 PM CST Mon Feb 12 2018

A low-level jet at 1500-2000 feet from the southeast at 35 to 40
KTS will veer more to the south during the early morning hours.
Surface winds will continue to be 5 to 10 KTS from the east-
southeast. The wind vector difference between the surface and
2000 feet will provide for 30 to 35 KTS of low-level windshear in
the lowest 2000 feet of the atmosphere through 13Z TUE. Otherwise,
expect VFR conditions. There may be a few snow flurries from 6Z
through 9Z TUE as well.




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.