397
FXUS63 KTOP 031954
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
254 PM CDT Wed Jul 3 2024

.KEY MESSAGES...

- Thunderstorms are forecast across the area late this evening and
overnight, which could bring strong winds to central KS and heavy
rainfall particularly across east central KS.

- A few severe thunderstorms are possible in eastern KS for the late
afternoon and early evening hours of Independence Day.

- Another chance for storms Saturday night into Sunday,
  otherwise slightly below normal temperatures continue into
  next week.

&&

.DISCUSSION...
Issued at 254 PM CDT Wed Jul 3 2024

Upper air pattern hasn`t changed a lot in the last 12 hours with
broad cyclonic flow over the northern tier of the US and the ridge
over the southeastern US leaving us within southwesterly flow aloft.
Sfc ridge has been slowly moving southeast from NE into KS today,
while the frontal boundary from yesterday has remained stationary
across southeastern KS. Scattered showers are still more robust
southwest of the area with light rain slowly moving northward. Lapse
rates are rather meager over the area, so thunderstorms should be
pretty isolated the rest of this afternoon into the early evening
with perhaps some dry time before the main round of storms comes in
late tonight.

A vort max passing through the flow aloft should initiate storms off
the High Plains later this afternoon into the early evening, and
CAMs remain in good agreement on those moving east into our area
late tonight. Most places should stay dry until after midnight,
except perhaps far western locations in the CWA. Generally speaking,
these storms should also weaken as they move east as MUCAPE looks to
remain under 1000 J/kg, but still can`t rule out a few damaging wind
gusts toward central KS if storms remain strong enough when they
enter the area.

Heavy rainfall looks to be the bigger concern for most of the area.
At this time, the moisture axis is progged to set up just south of
the forecast area where PW is forecast to be 2+ inches. This area in
southeast KS to southwest MO is also where the HREF shows the
strongest signal for rainfall amounts exceeding FFG, with the 90th
percentile having totals of 2-3". That said, the HRRR has not been
nearly as aggressive on this as some other individual CAMs have. If
more guidance starts to show some of these higher amounts creeping
north just a little bit, a Flood Watch may be warranted for our far
southeast counties.

The overnight batch of storms should push east of the area around
sunrise or shortly thereafter. A few additional showers and storms
may develop in central KS mid to late morning before moving out or
dissipating by afternoon. The main storm chance comes with a frontal
boundary crossing the area during the day, although lingering cloud
cover does lead to some questions about how well the atmosphere will
be able to recover and destabilize ahead of that boundary. Assuming
there is enough instability, thunderstorms look to develop near the
KS Turnpike around 4pm and then move east/southeast. Damaging wind
and heavy rainfall are again the main threats. Think the main time
frame for this activity should last until around 8pm, so most can
hope to see dry weather by the time fireworks celebrations begin.

By Friday, the main upper trough is progged to be in the Upper
Midwest and Great Lakes regions, leaving the area in northwest flow.
Another shortwave ejecting through that looks to bring our next
chance for storms Saturday night through Sunday. Otherwise,
temperatures are forecast to remain slightly below average
throughout the next 7 days with highs in the 80s and lows in the
60s.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1245 PM CDT Wed Jul 3 2024

Low clouds at TOP/FOE have scattered with mid/high clouds
remaining over all sites. Have removed mention of VCTS for this
afternoon, as scattered showers across the entire state have had
very little lightning observed with them and with weak
instability, would expect any TS to be too isolated to mention
in TAFs for the next several hours. Better chances for
convection are with storms coming in from western/central KS
overnight, so have added VCTS associated with that. The signal
for heaviest rainfall is well south of terminals, so any vis
reductions should be brief if any. Restrictions expected to come
with MVFR cigs during the morning following the storms. Some
guidance shows IFR may be possible during that time, but
confidence isn`t high enough to go that low with cigs just yet.

&&

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

&&

$$

DISCUSSION...Picha
AVIATION...Picha