394
FXUS63 KTOP 222338
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
638 PM CDT Sat Jun 22 2024

.KEY MESSAGES...

- Isolated storms, some severe, are possible through early
  evening. Damaging wind gusts are the main hazard.

- After a brief reprieve from the high humidity Sunday, heat
  indices from 105 to 110 are expected Monday and Tuesday
  afternoons.

- Cooler temps and late evening storm chances return midweek
  onward.

&&

.DISCUSSION...
Issued at 220 PM CDT Sat Jun 22 2024

Water vapor imagery this afternoon highlights the upper ridge
anchored over the southern plains while weak southwesterly flow and
an embedded shortwave trough push eastward through the northern
plains. Current analysis shows the frontal boundary entering north
central portions of the CWA while a mostly uncapped upstream
environment has sfc CAPE values exceeding 3000 J/KG at the current
hour. Limiting factors for more widespread storm development are the
poor midlevel lapse rates and lack of strong convergence along the
boundary. Nevertheless, CAMs are persistent in widely scattered
convection developing in the 4-5 PM time frame, pushing southeast
along the front through early evening. Steep low level lapse rates,
effective shear values less 30 kts, and DCAPE approaching 1500 J/KG
signals damaging wind gusts from collapsing storms being the primary
hazard. There is a lower possibility for hail and would only be
confined to cells that maintain a strong updraft.

Winds weaken from the north tonight behind the front with a low
possibility for valley fog to develop around sunrise. With the
temp/dewpoint depressions around 3F and possibility for winds to
stay up near 5 mph, confidence was not high for mention in the
forecast. Sfc ridge axis crosses through the region Sunday, bringing
slightly cooler and less humid conditions with highs in the low 90s
in the afternoon.

Unfortunately this is short lived as southerly sfc flow returns
Monday, as the region wedges between the midlevel ridge to the south
and the northern stream jet. Heat indices up to 110 are likely
Monday, while Tuesday`s indices approach 107 potentially as
dewpoints rise back into the lower 70s. Heat headlines are
anticipated for early next week. Both ensembles from GFS/ECMWF are
advertising an embedded shortwave trough making its way southeast
Monday evening into Tuesday, bringing storm chances through the day
Tuesday. This would remove the excessive heat concern, highly
dependent upon the timing of the wave, looking to be closer to the
Tuesday evening period. Upper ridge axis shifts to the east by
Wednesday, causing more uncertainty in where overnight MCSs track -
from Nebraska to possibly northern Kansas each evening through
Saturday morning. A stronger, cold front may track through the
region by Friday evening, providing much needed heat relief
next weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 638 PM CDT Sat Jun 22 2024

Isolated thunderstorm activity remains possible at TOP and FOE
for the next hour or two before a cold front moves through.
Given sparse nature of convection so far and little cloud
development upstream, have removed TS mention however. North-
northwest winds behind the front veer to the southeast late in
this forecast.

&&

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

&&

$$

DISCUSSION...Prieto
AVIATION...Poage