000
FXUS63 KTOP 042350
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
550 PM CST Tue Mar 4 2014

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Thursday)
Issued at 309 PM CST TUE MAR 4 2014

Temperatures have warmed nicely under the early March sunshine even
across the areas with snow cover. There has also been a decent
amount of snow melt this afternoon which is evident on a loop of the
visible satellite. There have been a few high clouds well ahead of
the approaching shortwave which is forecast to progress eastward
over the central and southern plains during the day tomorrow. An
inverted sfc trough pushes southward through the forecast area
tomorrow morning. Before the sfc trough moves through winds will go
calm for a few hours. With some extra moisture in the boundary layer
due to recent snow melt haze and or fog could develop especially in
the favorable locations. High clouds will increase this evening
which should inhibit strong cooling and the development of dense
fog. Low temperatures overnight drop down into the low to mid 20s.As
the shortwave ejects the Rockies tomorrow morning marginal lift
increases along and behind the boundary. A band of light snow should
move into north central KS around sunrise and traverse east and
southeastward through the forecast area. Forecast soundings indicate
that the a warm layer may be present therefore could not rule out
sleet. The warm layer appears to cool through out the day leading to
mostly snow as the main precip type. Amounts will be light and any
snow accumulations will be around half an inch or less. Precip
chances diminish during the late afternoon and evening hours from
northwest to southeast. Northerly winds behind the boundary and
cloud cover keeps highs tomorrow in the low to mid 30s. Tomorrow
night a sfc ridge of high pressure settles across the area likely
giving way to partly cloudy skies and light winds. Low temperatures
manage to drop into the upper 10s to low 20.

.LONG TERM...(Thursday Night through Tuesday)
Issued at 309 PM CST TUE MAR 4 2014

Friday looks to have a warm start as south winds will persist
through Thursday night along with warm advection. A cold front
will be poised to move into the area on Friday as well in the wake
of a northern stream trough that will be quickly moving through
the Great Lakes. The timing of frontal passage will depend largely
upon the strength of the trough, but the front currently appears
to be a bit weaker than other recent fronts with the upper flow
remaining nearly zonal...and should be slower to progress south.
On this note, trended toward the warmer end of temperature
guidance for Friday along with a slower wind shift. Some models,
particularly the NAM and SREF appear to be adversely affected by
perceived snow cover which will likely not exist, and have very
cool temperatures forecast.

All model guidance is then consistent in the development of a
trough over the four corners region which should then fill a bit as
it ejects east and southeast into the Plains. This weather maker
would potentially impact the local area from Friday night into
Saturday evening. Eventual evolution of this system is again
uncertain, and it shows some similarity to the past weekend`s
storm in that one of the main lifting mechanisms will be
frontogenesis (although much weaker) in between two storm systems
with some cold advection at the surface. However, it is quite
different in that this cold front is much weaker, as is the low
level dry advection, and the stronger upper level forcing with the
incoming trough has potential to be a bit more organized locally
if the track brings it relatively close to the area. The
temperature profile suggests a possible mix of precip types, but
mainly a mixture of rain and snow. All told, could see some
accumulating winter precipitation but current indications suggest
that it should NOT be a major storm.

For Sunday and beyond, expect a return to nearly zonal flow aloft
with warm advection in the low levels and occasional weak cold
frontal passages. Temperatures Monday and Tuesday are on track to
be near or above normal in the 50s...with some potential for 60s.
The next potential precipitation maker seems to be targeting the
middle to end of next work week.

&&

.AVIATION...(For the 00Z TAFs through 00Z Wednesday Evening)
Issued at 525 PM CST TUE MAR 4 2014

Vfr conditions will persist through 06z before some mvfr vsbys in
fog may develop ahead of advancing front with the light winds.
Lower vsbys and mvfr cigs in post frontal stratus should then
occur across the terminals through the remainder of the forecast
with light north winds. Although there is the potential for a
brief round of -SNPL at the TAF sites in the 19z-00z time
frame...confidence remains too low to include in the TAF fcsts at
this point.

&&

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

$$

SHORT TERM...Sanders
LONG TERM...Barjenbruch
AVIATION...63