178
FXUS63 KTOP 010613
AFDTOP

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

.KEY MESSAGES...

- Showers and thunderstorms move across the area overnight into Monday
  morning with best chances (50-70%) north of I-70.

- Heat Advisory has been issued for parts of north central KS Monday.
  Heat becomes more widespread on Tuesday.

- Periodic chances for storms for much of the week, though greatest
  risk for organized severe weather appears to be Tuesday
  afternoon/evening.

&&

.DISCUSSION...
Issued at 254 PM CDT Sun Jun 30 2024

Upper ridge remains dominant over the southern CONUS with two
troughs noted over the northern half, one heading towards New
England and the other moving through the Pacific Northwest. Sfc high
pressure in the Upper Midwest has kept cool easterly winds with
drier air filtering into the area throughout the day. As such, the
better moisture has remained west of the area, preventing showers
from materializing in north central KS where dew point depressions
remain rather large. Will maintain slight chances this afternoon in
case these manage to make it farther east, though confidence is
pretty low at this point.

Better rain chances come overnight into Monday morning, with
isentropic lift increasing across the area after midnight. CAMs
aren`t exactly in agreement on how widespread any thunderstorms will
be, as some depict the entire area seeing rain while others suggest
this activity looks confined to the I-70 corridor northward. In any
case, not expecting severe weather with MUCAPE of less than 1000
J/kg and weak vertical shear. That said, the moisture axis with Pwat
between 2-2.25" could result in some heavy downpours. The good news
is this system should be fairly progressive, so there doesn`t appear
to be a widespread flooding concern, but the increasing moisture in
the column could bring a quick inch or more of rainfall to isolated
locations. Isentropic lift weakens by midday, which should bring an
end to the rain from west to east through the morning, exiting the
area around 18Z.

North central KS areas will have more time to clear out and see
greater insolation with increasing humidity area-wide. More cloud
cover in far eastern locations should keep highs in the 80s, but
north central KS is still forecast to reach the mid 90s to near 100.
This should bring heat indices between 105-109, so have gone ahead
with a Heat Advisory for Cloud, Ottawa, Dickinson, and Clay
Counties. If it looks like these conditions could spread to
surrounding counties, more could be added to the advisory but think
this highlights the area of greatest confidence for now.

Heading into the evening hours, the main upper trough looks to be
far enough northwest of the area with the associated sfc front and
trough progged to develop thunderstorms in central NE. The LLJ
strengthens and is stronger to the north, which should keep the
majority if not all of the storm activity north of the area. Have
kept low PoPs along the KS/NE border Monday evening/night, but
confidence in these areas being impacted by severe weather is low.

By Tuesday, the upper ridge holds strong near the Gulf states with
the aforementioned northwestern trough slowly moving closer to the
area. The cold front should be the focal point for thunderstorms to
develop in the afternoon/evening as it crosses the area. There looks
to be sufficient shear and instability to support organized severe
weather, with all hazards possible, although wherever any tornado
risk exists would depend on where exactly the sfc low and triple
point set up.

The frontal boundary should push south of the area to bring some
relief to the heat by Wednesday with highs back into the 80s. The
baroclinic zone looks to hang around the area through Thursday with
embedded vort maxima keeping storm chances around through at least
the 4th of July holiday with mainly evening/nighttime periods
highlighted at this time. The end of the week looks quieter before
another system perhaps at the beginning of next week.

&&

.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.

&&

$$

DISCUSSION...Picha
AVIATION...Drake