000
FXUS63 KTOP 240550
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1150 PM CST Mon Feb 23 2015

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Tuesday)
Issued at 303 PM CST MON FEB 23 2015

Surface high pressure was located over northwest Missouri with the
surface ridge axis extending southwest into northeast Oklahoma. On
the back side of the high winds have come around to the southwest
across central and north central Kansas this afternoon. Nearly zonal
flow will continue through the night before shifting back to a
northwest flow aloft on Tuesday in response to an upper level trough
moving southeast into the Great Lakes late tonight and Tuesday.
Southwest winds will overspread the rest of northeast and east
central Kansas and continue through the night. Soundings suggest
that the lower boundary layer will be mixed through the night. That
said expect temperatures to cool into the teens tonight for lows.

A more westerly downslope flow is expected on Tuesday as well as
mixing down from around 900 MB which will send temperatures back to
around normal for late February in the mid to upper 40s. Winds will
shift to the west and northwest as a surface trough moves west to
east across eastern Kansas.

.LONG TERM...(Tuesday Night through Monday)
Issued at 303 PM CST MON FEB 23 2015

There continues to be a chance for mainly snow Wednesday night
across northeast and east central KS. Models continue bringing a
subtle shortwave across northeast KS. It appears that in general
the forcing for precip is relatively week as progs of omega are
not that strong, especially in mid levels of the atmosphere. But
there is still some Q vector convergence along with mid level
frontogenesis and plenty of saturation to warrant chance POPs.
The models have trended warmer during the day Wednesday and
perhaps slightly slower in bringing precip into northeast KS.
Because of this, chances for accumulating snowfall appear to
increase once the sun has set. However the GFS bufr soundings
remain aggressive with the wet bulb cooling and bringing surface
temps down below freezing once precip begins. Because of this have
maintained a mix of rain and snow across far northeast KS
Wednesday afternoon with highs in the upper 30s. Elsewhere over
the forecast area, temps are likely to be warm enough that any
precip should be rain through the afternoon. The general track of
the weak surface low still appears to be across north central KS,
generally from CNK to EMP. The GFS is slightly further west while
the GEM tracks the system further east. Concerns that the system
could track further east have precluded increasing precip chances
above 50 percent at this time. But the areas west of a Council
Grove to Westmoreland line look to have the better chances for
snow Wednesday night. Models are quick to bring the cold air back
in Wednesday evening and increase snow to water ratios pretty
quickly. Because of this, there is the potential for a quick
accumulations of a couple inches by Thursday morning if the system
does not move further east.

Thursday into Friday should remain cold and dry as another arctic
airmass moves through the area. Have only made some minor tweaks
to the previous temp forecast. The more complicated weather looks
to affect the area through the weekend. The GFS and ECMWF continue
to show the cold air initially over the area through the day
Saturday, lifting north with warm air advection causing a change
to the precip type Saturday night and Sunday. There are minor
differences in the thermal profile in the models today from
yesterday. However the GFS remains the warmer solution while the
ECMWF shows a tighter gradient between cold air over the northwest
and warm air southeast. Since this is still a fair ways out, have
maintained a chance for snow Friday night and Saturday with a mix
possible over east central and parts of northeast KS Saturday
night and Sunday. Precip could even change over to all rain Sunday
morning over east central KS with the models bringing 925 MB temps
of +5 into the area. There remains quite a bit of uncertainty in
the temps for Saturday night and Sunday so there is a wide range
of possibilities for precip. By Sunday night, another front is
expected to push southeast switching any remaining precip back to
snow. I expect precip to be winding down Sunday night as Dryer air
works its was south.

&&

.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1148 PM CST MON FEB 23 2015

Expect VFR conditions for the next 24 hours. VFR or MVFR scattered
to broken stratus may form Tuesday evening. West-northwest winds
will increase to 8 to 12 KTS with some gusts Tuesday Afternoon.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...53
LONG TERM...Wolters
AVIATION...Gargan