301
FXUS63 KTOP 010957
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
457 AM CDT Mon Jul 1 2024

.KEY MESSAGES...

- Heat returns over western zones today and along and southeast of a
modified cold front working into the area on Tuesday. Heat
advisories in effect.

- Several storm and rain chances set up across the area this morning
and increasing into Tuesday afternoon along the modified cold front.

- Storm chances may linger off and on through the 4th of July week
with repeated storm chances through at least Thursday with little
change to the weather pattern across the area.

&&

.DISCUSSION...
Issued at 455 AM CDT Mon Jul 1 2024

Only gradual changes to the overall upper air pattern lead to an
active week ahead for off and on rain and storm chances through
through the 4th of July holiday. The main belt of the Westerlies
remain positioned over the northern tier of the CONUS. An
anticyclone is set up over the southern Plains region with
subtropical moist plume returning into the central Rockies and
working around the apex of the dome of high pressure. Surface high
pressure has continued to exit the region with deeper moisture now
returning into western Kansas areas setting the stage for heat to
return to the area. Also, storm chances generally increase beginning
this morning into Tuesday and tend to persist through the week.

Showers have been spreading across the area this morning with a few
embedded thunderstorms. These should remain non-severe as mid level
lapse rates are around 6 C/km and thus lower overall MUCAPE is set
up across the area. Shear is also best off to the southwest of the
area where the LLJ is strongest. The weak isentropic ascent
advecting across the area this morning should allow for showers to
and embedded thunderstorms to remain through at least part of the
morning hours. Have increased POPs to 60-70 percent to account for
more scattered to widespread coverage.

As these storms exit the area, insolation resumes today over western
areas with increasing moisture in place. A heat advisory remains in
effect this afternoon over portions of north central Kansas. The
heat expands on Tuesday with consensus solutions not moving the
modified cold front into the area from Nebraska until around midday.
This should allow for H85 temps to rise into the mid to upper 20C
range ahead of the boundary. Mixing heights deepen prior to the
boundary working through the area, which should allow most areas
south of the Hwy 36 corridor to meet or exceed heat advisory levels
with heat index values as high as 108 degrees for at least part of
the afternoon. A heat advisory has been issued for Tuesday as well.

Regarding the overall severe weather threat, a few storms may be
possible later tonight as a vort max works north of the area through
Nebraska. A storm or two could still kick off along over northern
portions of the area. The probability for this appears low overall.
The best severe threat sets up Tuesday along the modified cold front
as the heat increases and moisture transport magnitude increases
bringing PWs up to around 2 inches, MUCAPES could reach 4000-5000
J/kg. Even though the better shear appears to be well behind the
frontal boundary, marginal shear could still allow for development
along the boundary. Mostly parallel flow favors stright-line
hodographs and possibly splitting storm modes or more interactions
which could allow for at least some flooding threat to set up. Hail
could be a threat if storms can remain semi-discrete. Wind appears
to be a primary hazard with inverted-v type forecast soundings and a
mixed layer top around 5-6kft. Higher LCLs would appear to limit the
potential for tornadoes but still not ruling the potential out. So
all typical sever hazards will need to be watched for come Tuesday
afternoon in the vicinity of the boundary.

After this, some uncertainty exists on timing and intensity of
repeated shortwaves streaming from west to east around the base of
the upper trough which looks to remain set up across the central
CONUS for much of the holiday week. Keep up-to-date with forecast
changes and have safety and backup plans in place as needed.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1232 AM CDT Mon Jul 1 2024

No significant changes for the 06Z forecast. Showers have been
developing SW of KMHK so adjustments to timing may be necessary
but current motion is tracking to the south of the terminal.
Marginal VFR cigs still expected to be in place may linger into
afternoon but strength of the inversion will depend on how
quickly they are eroded.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM this afternoon to 8 PM CDT this
evening for KSZ020-KSZ021-KSZ034-KSZ035.
Heat Advisory from noon to 8 PM CDT Tuesday for KSZ021-KSZ022-
KSZ023-KSZ024-KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-
KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

DISCUSSION...Drake
AVIATION...Drake