000
FXUS63 KTOP 080535
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1135 PM CST Fri Mar 7 2014

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Saturday)
Issued at 231 PM CST FRI MAR 7 2014

Active weather pattern across the Central and Western US has brought
an afternoon of warm temperatures across much of the forecast area
today.  A smaller scale shortwave trough is moving across eastern KS
at this time, advecting warm spring like temperatures near 60 from
Manhattan eastward. Meanwhile an upper trough across the northern tier
states has sent a coldfront southward into the Central Plains, and
is now nosing into the NW corner of the forecast area. Winds there
have shifted to the north northeast and become increasingly gusty as
you go north.  NW areas made it into the 40s before cloud cover and
cooler air started to move back in.  A stronger more amplified trough
is moving across the Central Rockies this afternoon and will aid in
bringing some light precipitation to the area tonight and
tomorrow.

For tonight, expect light precipitation to develop as the front
moves through and deepens with time.  Race between the colder
surface temperatures as well as time it takes to saturate aloft as
to what precipitation type to expect. Soundings indicate drizzle for
the evening with the NW tier becoming freezing drizzle around 03z.
Around midnight this area transitions to a chance of light snow
while areas along and southeast of Manhattan may see light freezing
drizzle or snow through 12z.  The precipitation area ends slowly
from north to south by tomorrow evening, with light snow possible in
the morning and a rain snow mix possible in the east for the
afternoon. Could see some light accumulations in the southern zones
as better lift comes across with the main wave, but less than an
inch of snow anticipated.  Some of the areas to the north may see
some slick spots on elevated surfaces and roadways in the overnight
hours.  Highs on Saturday much cooler than today with highs in the
40s northwest where it clears sooner, and middle to upper 30s to the
east.

.LONG TERM...(Saturday Night through Friday)
Issued at 231 PM CST FRI MAR 7 2014

Sunday and Monday continue to look like days in between systems
with temps gradually trending warmer. The models have started to
show a weak boundary trying to back door into the forecast area
for Monday which may hamper the warming trend. At this point it
looks to remain mainly to the north of the forecast area so have
continued with mid 60s to near 70 for highs Monday.

For Tuesday there remains some differences between the
GFS/ECMWF/GEM with the handling of the surface wave, although the
GFS has trended a little towards the ECMWF. The ECMWF remains the
deepest with a surface low Tuesday night and is also the coldest,
while the GEM and GFS have a hard time saturating the airmass over
northeast KS and are more progressive with the system. Given the
uncertainty, have continued with 20 to 30 percent chance pops for
rain or snow. The ECMWF would have mostly snow late Tuesday night
as it advects colder air into eastern KS. Since it is the more
bullish on QPF and the POPs in large part are derived from its
solution, have mentioned only snow in the forecast after midnight
Wednesday morning. Frontal timing will play a significant role in
what afternoon highs turn out to be Tuesday so have stayed with
the consensus here.

Am not to excited about POPs after 12Z Wednesday as most solutions
have the system east of the Mississippi by this time. But if the
solutions slow down a little more there could be some light snow
linger into Wednesday morning across far eastern KS so have kept a
slight chance here. The area should start to see westerly winds
advect warm air back in by Wednesday afternoon and this looks to
continue through the end of next week. With this in mind the
forecast has temps trending warmer with highs around 60 by Friday.

&&

.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1127 PM CST FRI MAR 7 2014

Low level dry is complicating the taf forecast this evening
especially over MHK. The chances for any drizzle overnight is
looking less likely. Have kept the mention at TOP/FOE where there
is more low level moisture and smaller dew point depressions. The lift
associated with this system may be too weak and short lived to
fully saturate. With increasing mid level lift later this morning
there is a slight chance for a light snow shower although it
appears several dry layers may be present. Have adjusted the the
taf sites to clear out much earlier.

&&

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

$$

SHORT TERM...67
LONG TERM...Wolters
AVIATION...Sanders