138 
FXUS63 KTOP 292141
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
341 PM CST Sat Dec 29 2018

.SHORT TERM...(This evening through Sunday)
Issued at 325 PM CST Sat Dec 29 2018

This afternoon an upper low was located along the southeast AZ and 
Mexico border. A shearing out positive tilt upper trough extened 
northeast into the upper Midwest. Weak ascent ahead of positive tilt 
H5 trough across KS has resulted in mid level cloud cover across the 
eastern half of the state. The western edge of the mid clouds 
extended from Hiawatha, southwest to Herington early this
afternoon. The clearing line will gradually shift east across the
CWA through the afternoon hours as the weak positive tilt upper 
trough shift east across the central plains.

Tonight through Sunday, the upper low across southeast AZ will dig 
southeast into northern Mexico, then lift northeast into southwest 
TX late Tonight. A lee surface trough will deepen across the 
southern high plains and will cause southerly low-level winds to
develop across the CWA Tonight through Sunday evening, which will
result in WAA and highs reaching the mid to upper 40s on Sunday. 
Cloud cover will begin to increase through the afternoon hours as
residual moisture begins to advect northward.

.LONG TERM...(Sunday night through Saturday)
Issued at 325 PM CST Sat Dec 29 2018

Sunday night through Monday, the upper trough across southwest TX 
will lift northeast into AR and southern MO by Monday afternoon. 
Most numerical models continue show a light precipitation region to 
the northwest of the upper trough moving northeast across east 
central KS after midnight and through the morning hours of Monday. 
Modified moisture return along with weak isentropic lift will cause 
light rain to develop south of I-35, and temperatures may remain 
above freezing keeping the precipitation in the form of light rain 
southeast of I-35 through Monday morning. Temperatures may web 
bulb cool to freezing or a degree or two below freezing, allowing
the light drizzle to change over to freezing drizzle northwest of
I-35, northward through the I-70 corridor. Areas west of a 
Hiawatha to Council Grove will remain dry during the early morning
hours of Monday. The light freezing drizzle may cause slick roads
along the KS turnpike Monday morning but temperatures will warm 
above freezing during the mid morning changing the freezing 
drizzle over to drizzle during the late morning and early afternoon
hours.

A more amplified upper trough will dig southeast across the central 
Rockies into the northern high Plains early Monday morning. 
Strong low-level CAA across the northern and central high Plains 
will cause a surface cold front to move southeast across the 
northern counties during the mid and late morning hours and across
the remainder of the CWA through the early to mid afternoon hours.
The 12Z NAM forecast soundings show saturated soundings up to 
850mb behind the front along with some weak isentropic lift. 
Therefore, directly behind the front there could be some patchy 
freezing drizzle across north central KS during the late morning 
hours and southeast across the remainder of the CWA during the 
afternoon hours of Monday. As the colder air deepens the patchy 
freezing drizzle will change over to snow flurries before ending 
during the evening hours. 

Monday evening (New Years Eve) through Tuesday (New Years), expect 
cold conditions, with temperatures dropping through the 20s into the 
teens by Midnight. Northwest winds of 15 to 20 MPH with higher gusts 
will cause wind chill indices to fall into the single digits to 
below zero along the NE border. During the early morning hours of 
Tuesday, low temperatures will fall into the single digits along 
the NE border with lower to mid teens across the remainder of east
central KS. Minimum wind chill indices will drop to 10 to 12 
degrees below zero along the NE border to around 5 below zero 
across east central KS. The winds should gradually decrease 
through the afternoon hours of Tuesday but remain in the 10 to 15 
MPH range through most of the afternoon. Highs will only reach 
the upper teens along the NE border to the mid 20s across east 
central KS. Wind chill indices will range from the single digits 
to lower teens through the afternoon hours.

Tuesday night through Wednesday night, the center of a 1036 mb 
surface ridge axis will move southeast across eastern KS late 
Tuesday night into Wednesday. The trough across the central 
Rockies and northern plains will continue to shear apart with the 
more amplified portion of the southern stream H5 trough digging 
southeast into west TX Wednesday afternoon, then moving east- 
northeast across north central TX and eastern OK. The residual 
moisture and ascent ahead of the southern stream H5 trough will 
remain south of the CWA, so expect dry but cold conditions. 
Overnight lows Tuesday night will drop into the single digits and 
lower teens. Highs on Wednesday may moderate a bit with lower to 
mid 30s expected.

Thursday through Saturday, a broad upper level ridge across the 
western US will slowly shift east into the plains by Saturday. 
Expect a warming trend as zonal flow across the central Rockies 
will cause a lee surface trough to deepen. Southerly winds and WAA
will cause highs to warm into the mid 40s Thursday afternoon and 
lower 50s Friday and Saturday afternoon.


&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1143 AM CST Sat Dec 29 2018

Expect VFR conditions through the next 24 hours. West-northwest
winds under 10 KTS will gradually veer to the southwest this
afternoon and diminish to under 5 KTS this evening.


&&

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

$$

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