Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 132035
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
335 PM CDT Thu Mar 13 2014
.SHORT TERM...(This Evening through Friday)
Issued at 240 PM CDT THU MAR 13 2014
An upper level trough across west central Canada will dig southeast
across the northern plains into the great lakes region. This will
cause a weak cold front to push southward across the CWA during the
morning hours of Friday. Winds will switch to the north behind the
front and high temperatures will be about 5 to 10 degree cooler than
Today, with highs in the lower to mid 60s.
This afternoon deeper mixing has caused dewpoints to mix down into
the lower 20s to upper teens at 200 PM. Winds were beginning to pick
up to 15 to 20 MPH with gusts of 20 to 25 MPH across the CWA. The
wind and wind gusts will continue to increase through late afternoon
hours. Most areas will reach red flag warning criteria after 300 PM.
Towards sunset, the mixed boundary layer will decrease and wind
gusts should diminish as dewpoints rise into the lower to mid 20s.
Therefore, the red flag warning should be allowed to expire by 700
Tonight, winds will continue to be from the south-southwest at 15 to
20 MPH. The surface winds may decrease ahead of surface cold front
after midnight then pick back up to 15 to 20 MPH behind the cold
front. Overnight lows will only drop into the mid 40s across the
east central KS, with mid to upper 30s across north central KS.
Friday, Northwest winds of 15 to 20 MPH during the morning will
diminish to under 10 MPH through the afternoon hours as a surface
ridge of high pressure builds southeast across the state of KS.
Highs will reach the lower to mid 60s.
.LONG TERM...(Friday Night through Thursday)
Issued at 240 PM CDT THU MAR 13 2014
Friday night and Saturday...Short range models quite consistent in
moving weak high pressure ridge across eastern KS and MO Friday
night and developing minor low pressure area across southern
Nebraska by mid day Saturday. The low/inverted trough then
traverses well into eastern KS by Saturday evening. Moisture
should surge northward with 50 degree dewpoints making it to the
KS Turnpike by 00Z Sunday. The NAM keeps the richer low-level
moisture and precip chances farther south Saturday
afternoon/evening and was an outlier, so disregarded in this time
period. Thus, precip chances with possible thunder increase
Saturday afternoon in EC KS.
Saturday night and Sunday...This is kind of a messy forecast with
models differing some on timing and phasing potential of southern
and northern stream shortwave troughs. Despite these timing
differences, best chances for precip will be in the eastern 2 to 3
tiers of counties in our forecast area, with precip ending in all
but our far southeastern forecast area on Sunday afternoon. Temps
will be cold enough for a rain/snow mixture, or a changeover to
all snow for awhile late Saturday night/early Sunday morning. Do
not expect any accumulation at this time, although the 12Z ECMWF,
with the stronger, closed off upper low, does produce a couple
tenths of an inch of QPF Sunday morning with temperatures cold
enough for snow. This could result in a change in the forecast if
other models come into line with ECMWF with a stronger closed
After that, the next chance for precipitation could be Tuesday
with another upper trough and low pressure area coming through in
WNWLY flow aloft. Considerable model differences in forecast timing
and location of surface low lend low confidence to prediction of
precip chances. Despite that, there is enough of a signal over
far northeastern KS to introduce low POPs at this time.
For Wednesday and beyond, northwest flow aloft sets up and precip
chances should be negligible.
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1234 PM CDT THU MAR 13 2014
Expect VFR conditions through the next 24 hours. Strong low-level
wind-shear will be possible at the terminals, as winds at 1500 feet
above the surface increase to 55 to 65 KTS between 6Z and 12Z FRI,
and surface winds decrease to 10 KTS to 12 KTS after midnight. A
weak front will shift winds to the north-northwest after 12Z FRI.
RED FLAG WARNING until 7 PM CDT this evening FOR KSZ008>012-