000
FXUS63 KTOP 011138 AAA
AFDTOP

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TOPEKA KS
538 AM CST Sun Feb 1 2015

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 302 AM CST SUN FEB 1 2015

Main shortwave trough now digging into the central high plains will
continue to move east/southeast through the day and amplify. This
will take a surface low now over central Kansas eastward into MO
this afternoon. As this occurs...one band of light snow now
expending from central KS to eastern NE will move through this early
this morning with more light snow likely wrapping southeastward
across mainly the northeast half of the cwa through midday and early
afternoon. Expect additional snowfall amounts through the daytime to
range from less than a quarter of an inch across the southern
counties to an inch and a half near the NE border. Also...as the
front moves through this morning...northwest winds will increase to
20 to 30 mph with some gusts near 40 mph which could produce some
localized blowing or drifting snow across the northern counties. The
additional snow north could leave some areas with a total of 2 to 5
inches...so have continue the winter weather advisory in the
northern cwa through the afternoon. Temperatures will also fall most
areas today as the front moves through. Portions of the north
central will fall into the teens while the later arrival of the
colder air in the east central drops readings into the 20s in the
afternoon.

Although a few flurries may linger in the far northeast corner early
this evening...tonight should be dry but bitterly cold again.
With late night lows in the range of zero north to 10 far
south...wind chills indices will range from around 2 below south to
-11 northern counties.

.LONG TERM...(Monday through Saturday)
Issued at 302 AM CST SUN FEB 1 2015

Monday and Monday night, the center of a surface ridge high pressure across
eastern KS will move east-southeast across the mid and lower MS
river valley by Monday night. After a cold start to the morning
with lows in the single digits, temperatures will moderate into
the mid 20s to lower 30s, as surface winds become southerly.
Southerly winds Monday night will only allow overnight lows to
drop into the 20s.

Tuesday, A lee surface trough will deepen across the western KS and
west central NE. Ahead of the surface trough, southwesterly winds
will advect downslope warming airmass over western KS, east across the
state. Look for highs to warm into the lower mid 50s across much of
the CWA, though the northeast counties may only see mid to upper 40
degree highs.

Tuesday Night through Wednesday night, An upper level trough across
central Canada will dig southeast into the northern plains on
Wednesday. A secondary trough rounding an H5 ridge axis across the
western US will phase with the northern stream H5 trough cross the
central plains. This will cause another surge of cold air to move
southward across the CWA late Tuesday night and Wednesday. As the
central plains trough digs southeast across eastern KS, there should
be enough frontogenetical forcing for a band of light snow to
develop. These clipper type troughs usually do not provide much in
the way of snowfall, thus most of the area will only see a dusting
up to 1 inch of snowfall Wednesday and Wednesday night. The snow
will end from northwest to southeast during the late evening hours
of Wednesday and early morning hours of Thursday. Highs on Wednesday
will be colder with highs in the mid 20s across the northern counties
and lower 30s across the extreme southeast counties. Lows
Wednesday Night will drop into the single digits to lower teens.

Thursday through Thursday Night, a surface ridge of high pressure
will move east across the CWA Thursday Afternoon. Light northeast
winds will become southerly during the evening hours of Thursday.
The weak low-level CAA will keep highs in the lower 20s across
extreme northeast KS to the lower 30s across the southwestern
counties.

Friday through Saturday, the northwesterly flow aloft will become
zonal Friday and Saturday. A lee trough will deepen across the
central high plains. South-southwesterly winds will help to moderate
temperatures into the 40s on Friday with lower to mid 50s on
Saturday.

&&

.AVIATION...(For the 12Z TAFs through 12Z Monday Morning)
Issued at 524 AM CST SUN FEB 1 2015

IFR cigs and MVFR vsbys in mainly light snow should continue 18z
before lifting to MVFR by 21z. North to Northwest winds will
steadily increase thru 14z into the range of 20-25 kts with gusts
at times over 30 kts. Gusty northwest winds of 15 to 25 kts
will then decrease to around 14 kts sustained by the 04Z-06Z
time frame as ceilings near 2500 feet scatter to VFR.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR
KSZ008>012-023-024.

&&

$$

SHORT TERM...63
LONG TERM...Gargan
AVIATION...63