Area Forecast Discussion
Issued by NWS Topeka, KS

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798
FXUS63 KTOP 141720
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1120 AM CST SUN FEB 14 2016

.UPDATE...
Issued at 511 AM CST SUN FEB 14 2016

The latest RAP and NAM isentropic progs continue to show the
better saturation and lift focusing to the east of the forecast
area. With the HRRR handling the shower activity earlier and
taking it out of the area, have reasonable confidence that precip
is pretty much over. Will be sending out an update to the forecast
to reflect this.

&&

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 324 AM CST SUN FEB 14 2016

08Z water vapor imagery shows a shortwave moving east across NEB and
SD and a weaker wave across AZ and NM. There also appears to be a
shortwave over British Columbia moving towards ID and MT. Surface
observations show a general trough of low pressure across the Great
Plains from west TX to the Canadian boarder as the arctic high
pressure system continues to move east. Locally, surface winds have
generally remained from the east with shallow dry air remaining over
the forecast area noted by the dewpoints still in the single digits.

For today, models show the best forcing and isentropic upglide
occurring now with the shortwave just north of the forecast area.
Once it passes to the east, the warm air advection pattern becomes
focused to the east of the forecast area and should bring an end to
precip chances for the rest of the day. Radar is starting to show
some shower activity developing over eastern KS similar to the HRRR.
RAP forecast soundings hint at some weak elevated instability but
the low level moisture has been slow to move into east central KS.
Will increase chances for precip and mention freezing rain in the
forecast. This activity should be short lived and be moving east of
the area by 8am. Think there should be some sunshine by the
afternoon behind the shortwave. So with some insolation and warm air
moving in from the west, high are forecast to be around 50 to the
mid 50s.

Tonight models show another low amplitude wave moving across the
forecast area with the GFS most aggressive in generating a couple
hundredths of precip. Model progs of forcing are rather disorganized
and continue to show deep layer moisture lacking. Because of this
think any precip is likely to remain a trace event. Precip type is
somewhat uncertain in that both the GFS and NAM forecast soundings
show a decent warm nose of +3 to +5 C. So snow is unlikely, and with
the dry air in place within low levels of the atmosphere and a
westerly wind this afternoon and evening unlikely to advect low
level moisture into the area, drizzle does not look much more
likely. The GFS would suggest temps are warm enough for any precip
to be liquid. Meanwhile the NAM has surface temps around freezing
but a lot more dry air to overcome. Think the NAM is probably
handling the thermal profile within the boundary layer better than
the GFS so have lows in the lower 30s for tonight. As for precip
type, will stick with sprinkles which possible could freeze on
elevated surfaces if there is not to much low level dry air.

.LONG TERM...(Monday through Saturday)
Issued at 324 AM CST SUN FEB 14 2016

Another shortwave in the northwest flow aloft is forecasted to track
over the area Monday morning, but should be mostly dry. The next in
the parade of shortwaves will pass over the area Tuesday morning,
and like the previous waves will lack any appreciable low level
moisture. Also, the better mid level moisture will be centered over
IA. There is a chance there may be enough precipitation falling into
this dry layer for rain to reach the surface. The better chances for
this light rain will be mainly over far northeast KS, and amounts
look to be rather minor. Luckily there is a deep enough layer of
above freezing temperatures even after saturation therefore frozen
precipitation should not be an issue. Beyond that an upper ridge
will build eastward over the central US causing temperatures to warm
well above normal. By Thursday the guidance shows highs around 70,
but given the models tendencies to underestimate these situations
have increased the highs by a few degrees. There will be some
concern for elevated fire danger on Thursday and Friday given the
warm temperatures and gusty winds.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1120 AM CST SUN FEB 14 2016

VFR conditions are expected through the period.  Mid-level clouds
will move through the area overnight before skies begin to clear
tomorrow morning.


&&

.TOP Watches/Warnings/Advisories...
NONE.
&&

$$

UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...Sanders
AVIATION...Heller



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