782
FXUS63 KTOP 072345
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
545 PM CST Fri Feb 7 2025

.KEY MESSAGES...

- Near average temperatures continue through Saturday before colder
  air arrives by Sunday, and colder still by Tuesday.

- There is a slight chance of drizzle tonight into early Saturday,
which could be freezing drizzle near the Nebraska border, but
confidence overall is low (15-20%).

- Two systems bring snow chances during the first half of next
  week, which look to result in at least some accumulations.

&&

.DISCUSSION...
Issued at 246 PM CST Fri Feb 7 2025

At mid afternoon, a nearly zonal flow was noted across the Rockies
and into the Plains. A short wave was moving across Montana and
Wyoming. Further upstream a trough wave moving into the Pacific
Northwest. At the surface low pressure was developing in the lee of
the Rockies while a warm front was noted across northern Oklahoma.

Moisture continues to move northward into Kansas this afternoon as
clouds have overspread much of eastern Kansas. Low level southerly
flow will advect moisture northward this evening over the frontal
boundary. Models show isentropic lift in the 925-850mb layer and
very low condensation pressure deficits. Forecast soundings show
potential for some periods of light drizzle to develop later this
evening and tonight. Isentropic downglide commences after 08Z which
will bring an end to the drizzle. Areas along the Nebraska border
may have a period of freezing drizzle tonight, but is not expected
to have widespread hazards. A cold front will move south later
tonight and Saturday morning. Dry air advection behind it will scour
out clouds by afternoon with some sunshine in the afternoon hours.
Cold air advection Saturday night will drop lows into the teens and
highs on Sunday will only top out in the 30s.

For next week there are a couple of periods of light snowfall that
are forecast. A zonal to southwesterly flow across the Plains is
forecast Monday into Tuesday with energy ejecting out of the Rockies
into the Plains. Frontogenetic forcing at mid levels increases
Monday afternoon and lift increases within a saturated dendritic
snow growth zone. Forecast soundings support all snow for this
event. There are some model differences in the deterministic models
and in the ensembles so amounts and location of snow bands will
likely be more defined over the next few days.

The second period is Tuesday night into Wednesday night as a mid
level trough moves out across the Plains. The column will be
favorable for all snow once again with this system. Good lift is
forecast in the dendritic snow crystal zone and frontogenesis within
a deep layer develops across the area. Between the two systems there
is a 60 to 90 percent probability that we will see at least 4 inches
of total snow. WIll continue to monitor these events over the coming
days.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 545 PM CST Fri Feb 7 2025

Degrading conditions are expected this evening and overnight
with lowering cigs and reduction to VSBY from drizzle/BR. IFR
cigs and drizzle appear likely by 08z or so with the potential
for periods of LIFR cigs and VSBY in the 1-3SM range, especially
at KTOP/KFOE. Conditions slowly improve Saturday morning with
VFR conditions favored to return by early afternoon. Southeast
winds to begin the period become northerly around 10z and increase
by 14-15z with gusts of 20-25kts through the day Saturday.

&&

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

&&

$$

DISCUSSION...53
AVIATION...Flanagan