Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 231739
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1239 PM CDT Sat Mar 23 2024

.KEY MESSAGES...

- Wind Advisory Sunday through Sunday night as a dynamic storm
  system brings wind gusts up to 50-55 mph.

- A few strong to severe thunderstorms also possible Sunday evening,
mainly towards central Kansas.

- Still potential for light snow across north-central Kansas
  Monday night.

&&

.DISCUSSION...
Issued at 340 AM CDT Sat Mar 23 2024

A look at water vapor imagery this morning shows one deep trough
over the West Coast and another trough approaching the East Coast,
with broad ridging in between. Despite the upper ridging, surface
ridging emanating from strong high pressure over the Dakotas is
keeping chilly temperatures in place. Today looks to stay chilly but
mostly on the dry side, despite an approaching weak vorticity maxima
currently over the central Rockies. Mid-level ascent ahead of this
feature will try to develop a few scattered showers, with wet bulb
temperatures even supporting some initial flurries north of I-70.
However with plenty of dry air near the surface, any precipitation
that does reach the ground will remain negligible - a hundredth or
two of an inch at best.

The more impactful weather still arrives Sunday, as the deep western
trough shifts east and a sub-985 mb surface low develops across
eastern Colorado and western Kansas. SLP this low is below the 0.5th
percentile of climatological values, approaching but not quite to
the level of the March 13, 2019 system. Still, such a dynamic system
will lead to a very tight pressure gradient across the area, with a
60 kt LLJ developing in response. Thick cloud cover and a lack of
deep mixing will prevent these winds from fully reaching the
surface, but nevertheless we will see a period of very strong
southerly winds. Sustained winds 25-35 mph with gusts 45 to 55 mph
are expected, with high enough confidence to go ahead with a Wind
Advisory from Sunday morning to Monday morning across the entire
area. As the LLJ strengthens Sunday morning, this will also help to
develop widespread showers across the area with perhaps a rumble or
two of thunder. By Sunday evening, the surface low will begin to
lift northeast towards the area. Thunderstorms are expected to
initially develop across central Kansas early evening. The
greatest instability and related greatest severe weather threat
will remain southwest of our area, and thunderstorms could
outrun the narrow instability axis and weaken before they make
it into our forecast area. However there is a conditional threat
(40%) that weak (~500 J/kg) surface based instability allows
more robust convection to persist into our western counties. If
this scenario occurred, the robust dynamics would support a
lingering strong/severe storm risk. Damaging wind gusts 60-65
mph would be the primary hazard, given the widespread 50-55 mph
gusts even outside of storms. Hail to around 1 inch and even a
brief tornado would also be possible as secondary hazards.

Low pressure moves off to the north-northeast Monday morning,
sweeping a strong cold front through the area. Temperatures fall
into the 30s and 40s behind the front. Guidance continues to hint
that a band of light snow develops across north-central Kansas
Monday night, in an area of enhanced lift underneath the upper low.
Ensembles show a roughly 30-60% chance of accumulating snow across
portions of north-central Kansas. However guidance sometimes
under-does the amount of dry air in these scenarios, thus
overdoing the snow potential. So not fully bought into snow
occurring, but certainly can`t rule out an inch or so of light
snow. Cooler temperatures last into mid-week as the deep upper
trough slowly shifts east. Sub-freezing temperatures look likely
each morning through Thursday, with teens even possible
(30-50%) Wednesday morning.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1232 PM CDT Sat Mar 23 2024

Strong winds and precipitation become the main concerns this
TAF period, with lowering ceilings an issue toward the end of
the period. Tonight, a strengthening LLJ will create a few
hours of LLWS before sfc winds increase around 12Z. After 12Z,
southerly winds become sustained at 18 to 25 kts with gusts to
around 35 kts. Rain showers and MVFR CIGS will move eastward
across the area into midday, impacting KMHK initially and the
Topeka airports by the end of the 18Z period.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 7 AM Sunday to 10 AM CDT Monday for KSZ008-
KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-
KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-
KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

DISCUSSION...Reese
AVIATION...Teefey


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