Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 120531
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1131 PM CST THU FEB 11 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 226 PM CST THU FEB 11 2016
Active northwest flow pattern continues through the central plains
this afternoon. Water vapor imagery shows an embedded shortwave
trough developing light snow across eastern Nebraska. These snow
showers may possibly clip Brown county as the wave pushes into MO
this evening, however given the high cloud bases and lack of deep
moisture should only result in a few flurries at best. Better
frontogenetical forcing lies over Missouri with light snow expected
just east of the CWA.
With the low stratus lifting northward this afternoon, the next wave
will force the stratus shield further south again Friday morning.
Increased mixing of dry air behind the cold front will help to
clear some of the cloud cover over far eastern Kansas, while mostly
cloudy skies are likely for the central and north central areas of
the CWA. Highs are once again likely to remain below normal in the
mid to upper 30s given the persistent cold advection from the north.
.LONG TERM...(Friday Night through Thursday)
Issued at 226 PM CST THU FEB 11 2016
This weekend...Friday night through Sunday...
Northwest upper flow continues this weekend with fast moving,low
amplitude, shortwave troughs moving through the central U.S. All
of the 12 UTC models are in fair agreement with the mass fields
concerning the strength and timing of one shortwave which crosses
the upper midwest Saturday night and Sunday. The NAM appears to be
more pronounced with moisture return in advance of the wave much
more coverage of light QPF across eastern Kansas Saturday night
and Sunday morning. The GFS/ECMWF/GEM are all drier and have
little or no QPF. It seems reasonable given the speed of the
shortwave and the relatively short duration of the return flow,
that it will be difficult to saturate to the point of producing
much precipitation. We are planning on keeping small POPS going
Sunday morning over the eastern counties with very low QPF
amounts. Precipitation type is difficult. The NAM has some ice in
the sounding, but the GFS shows very little or no ice. Will go
with a small chance of mixed precipitation Sunday morning.
Saturday will be cold with the center of a cold Canadian high to
the east of Kansas and easterly flow over northeast Kansas. After
the surface trough passes Sunday morning, northeast Kansas should
be in modified Pacific air and significant warmer.
Sunday night through Thursday...
Northwest flow aloft will continue to dominate through the period. A
secondary wave is expected to deepen across the central plains in
the Sunday-Monday time-frame. GFS deepens the trough across the area
while the EC is further east. Have at least slight chance pops
across much of the area Sunday night and Monday morning. Both the EC
and GFS suggest 850 temperatures will be near 2 to 5 degrees C,
minimizing the possibility for snow. GFS maintains surface
temperatures above freezing for both Sunday night and Monday while
EC hovers surface temperatures right at freezing. Went with a GFS
bias and just rain as a precipitation type. Quiet weather is then
expected through the end of the period as an upper level ridge will
move across the plains. Temperatures will warm into the upper 50s
and 60s for Wednesday and Thursday as WAA increases ahead of the
trough located across the western US.
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1127 PM CST THU FEB 11 2016
For the 06z TAFs, light winds will continue to veer to the northwest
overnight with increasing winds by sunrise. Some wind gusts of
around 20kts will be possible at KTOP/KFOE mid morning through the
afternoon. Short-range models along with the latest satellite
imagery have shown increasing confidence in MVFR cigs skimming
over the TAF sites for a few hours early this morning, however
there is still some uncertainty with regards to how long these
MVFR cigs will remain in place over the TAF sites. Winds will
diminish some during the evening with mid-level clouds moving into