000
FXUS63 KTOP 181955
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
255 PM CDT Thu Apr 18 2024

.KEY MESSAGES...

- Winds subside this evening with cooler temperatures lingering
through this weekend.

- There could be some frost Sunday morning impacting gardeners who
have plants in the ground.

- Light rain is possible towards central KS late Friday night
  into Saturday morning; better rain chances come Monday into
  Tuesday.

&&

.DISCUSSION...
Issued at 255 PM CDT Thu Apr 18 2024

The upper air pattern at 19Z depicts broad cyclonic flow across much
of the northern CONUS with an upper low centered over southern
Manitoba. While the surface cold front that passed through this
morning is now well southeast of the area, the 850mb front is still
lagging near the KS Turnpike where light returns can still be seen
on radar. High pressure is noted across western KS and NE. Any
remaining showers should come to an end within the next hour or so
as the 850mb boundary moves out. This should also help stratus to
scatter out from west to east as is already occurring based on
satellite imagery.

Heading into this evening and overnight, the pressure gradient
should relax as sfc ridging moves in, bringing an end to the gusty
north winds. There appears to be a very subtle perturbation that
ejects through the central Rockies into the High Plains, which
brings some mid to high cloud cover into the area after midnight. A
few models (namely the GFS and WRF-based CAMs) try to generate some
light QPF associated with this early Friday, but am skeptical due to
the fact there isn`t much forcing and forecast soundings are dry
below 700-750mb. Have kept a dry forecast, but the cloud cover does
lead to some uncertainty on how far temperatures drop tonight,
particularly towards central KS. HREF probabilities indicate a
low chance for temperatures to get cold enough to develop frost
anywhere in the area, whereas the NBM has probabilities for lows
<36 degrees pushing 50% in isolated locations near the KS/NE
border. This plus incoming cloud cover led to the decision to
hold off on any frost headlines for counties near the state
line, but if temperatures drop faster this evening than
currently forecast, an advisory may need to be considered.

Temperatures Friday look to reach the upper 50s to low 60s with
lighter winds in place. Another weak upper disturbance is progged to
bring light rain to mainly western locations late Friday night into
Saturday morning. PoPs are limited to 10-40% with QPF of only a few
hundredths. The cloud cover should preclude frost formation Saturday
morning, but cooler air Sunday morning looks to bring lows into the
30s across the entire area. Questions remain on how cloud cover will
impact those temperatures as well, but northern locations stand the
better chances of seeing frost/freeze conditions so this remains the
main day to watch for headlines.

Low-level flow returns to the south/southwest by Monday, resulting
in moderating temperatures with highs reaching the 70s for the first
part of the work week. A shortwave moving through the Upper Midwest
looks to bring a weak cold front through the area Monday, bringing
our next best chance (50-60%) for showers and storms. The better
upper support appears to be well north of the area, however, so time
will tell what kind of impacts we see in our CWA.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1232 PM CDT Thu Apr 18 2024

The main convection at this point is northeast of Topeka
terminals heading into MO. Will continue to monitor in case
amendments are needed, but have opted to leave out mention with
a small chance for an additional shower this afternoon.
Otherwise, MVFR stratus is expected to scatter out by 20-23Z.
Northerly winds remain gusty until early this evening, at which
point they should stay light the rest of the period. Mid to high
clouds increase overnight into Friday morning.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Picha
AVIATION...Picha