614
FXUS63 KTOP 270737
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
237 AM CDT Thu Jun 27 2024

.KEY MESSAGES...

- Thunderstorms tonight may pose a wind risk as they move in
  from the west.

- Chances for severe storms look to be higher Friday afternoon
  and evening with supercells presenting an hail, wind and heavy
  rain risk.

- Hot and humid conditions Friday are forecast to make it feel
  like it is between 103 and 109 degrees Friday afternoon.

&&

.DISCUSSION...
Issued at 237 AM CDT Thu Jun 27 2024

An upper ridge was centered over northern Mexico per the 07Z
water vapor with an upper low over the Pacific Northwest and
shortwave energy lifting into the northern Rockies. At the
surface, weak ridging over the upper Midwest had nosed into
northeast KS. This had displaced the deeper moisture south along
the Red River valley and Gulf Coast.

The main change to the forecast today was to delay POPs for eastern
portions of the forecast area until the late afternoon or evening.
Models show the better moisture return developing through the high
plains with some influence from the surface ridge hanging on over
northeast KS. This keeps the deeper moisture axis to the west with
model progs developing little if any instability over the forecast
area and in fact show dewpoint temps mixing out a little. This
should make it feel a little cooler, but increasing mid and high
clouds from the west could limit insolation through the afternoon
also keeping highs in the mid and upper 80s. For thunderstorm
potential, think this should mainly be driven by what convection
develops off the high plains. Forecast sounding show some mid level
saturation with a weak vort max passing west to east. This may be
enough for some isolated rain showers in the afternoon. But with the
lack of instability, the severe risk is going to have to come from
the storms developing to the west. A developing warm air advection
pattern into north central KS could bring in some elevated
instability that could sustain convection moving in from the west
with mainly a damaging wind risk. Forecast soundings are not as
aggressive with the elevated instability advecting into eastern KS
and the risk for severe storms may be quite a bit lower as storms
move from west to east tonight.

For Friday, think there should be a pause in precip chances through
mid day as subsidence from overnight storms works east. This is
expected to allow for a very hot and humid airmass to develop by
Friday evening as a shortwave trough propagates east over the
northern plains and brings a weak boundary into northern KS Friday
night. Wind fields are forecast to be better for organized
convection and with MUCAPE between 4000 and 5000 J/kg. This could
lead to a few supercell storms developing along the boundary with a
damaging wind and hail risk. PWs are also forecast to be very high
at over 2 inches. This should lead to the potential for torrential
rainfall and localized flash flooding should storms train over a
location. Forecast highs in the 90s combined with dewpoints in the
lower and middle 70s looks to create heat indicies in the 103 to
109 range for a good portion of the forecast area.

Models show little change in the pattern through the middle of next
week with upper ridging remaining just south of the forecast area
and the mean westerlies staying north. Some amplification in the
ridge could bring hot temperatures back to the area to start off the
work week. Another frontal boundary looks to slip south by
Wednesday. With this potential focus, the forecast has higher chance
POPs (40 to 50 percent) Tuesday night and Wednesday. Otherwise
precip chances look to be driven more by mesoscale features on the
fringes of a surface high that is forecast to nose into the central
plains through the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1204 AM CDT Thu Jun 27 2024

The latest models are slow to return the deeper moisture into
northeast KS and the RAP and NAM actually show surface dewpoints
mixing out in the afternoon. So instability looks to be limited
through the afternoon for convection. A weak shortwave thursday
night is forecast to bring higher probabilities for SHRA and TS,
mainly towards the end of the forecast period and beyond. Think
VFR conditions will prevail with just some mid and high clouds
increasing from the west.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters