014
FXUS63 KTOP 120551
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1251 AM CDT Sun May 12 2024

.KEY MESSAGES...

- Rain chances increase through the day Sunday into the 85 to 98
  percent range Sunday night into Monday morning. Showers may be
  more hit or miss in the morning and early afternoon hours of
  Sunday.

- Total rainfall is forecasted to range between 0.8 to 1.78
  inches

- Another system expected to bring chances for showers and
  storms Wednesday through Friday morning.

&&

.DISCUSSION...
Issued at 234 PM CDT Sat May 11 2024

Early this afternoon an upper level trough was located across the
southwestern US. A down stream H5 ridge was shifting east across the
southern Plains and KS. An upper trough across the eastern Great
Lakes was digging southeast into the New England and the Mid Atlantic
States.

At the surface ea broad surface ridge of high pressure was
centered across western AR and extned northward across western
MO. Surface winds were light and variable along and just west of
the surface ridge axis. Winds were become southerly across
north central KS.

Tonight through Tuesday:

The upper trough across the southwestern US will lift east-northeast
across the central Rockies, then east across KS and the southern
Plains Sunday night into Monday night.

Residual moisture return across the southern and central Plains will
result into isentropic lift, that will provide enough ascent for a
few to scattered rainshowers to develop across north central KS
after sunrise on Sunday. These showers will gradually shift east
through the morning hours into northeast and east central KS. Later in
the afternoon the DCVA ahead of the upper trough will improve the
large scale ascent and richer moisture will begin to advect
northward into the Plains. The stronger ascent will cause widespread
showers along with scattered thunderstorms to develop in western and
central KS and push east into north central late Sunday afternoon,
then east across the CWA Sunday night into Monday morning, with
the greatest PoPs occurring late Sunday night into Monday
morning, with a 85-98 percent chance of rain. MUCAPE is expected
to be under 1000 J/KG and effective shear should remain in the
20 to 25 KTS range. Point forecast sounding show any
thunderstorms to remain elevated across the CWA Sunday night
into Monday morning. The chances for any strong or marginally
severe thunderstorms look to be very low.

A surface front will pass southward across the CWA late Monday night,
as a surface low deepens over south central KS and tracks east-
northeast into western MO. by Noon on Monday. The heavier rainfall
and thunderstorms should shift east and exit the CWA Monday
afternoon, with residual showers rotating around the 850mb low
across mainly the eastern half of the CWA. The showers should
end early Monday evening as the H5 trough axis shifts east-
northeast into the upper Midwest.

Total rainfall from Sunday through Tuesday morning will range
betweeen 0.8" to 1.8" across the CWA. It should be a gradual
moderate rainfall but there could be heavier rainfall with any
thunderstorms Sunday night. I don`t expect any flooding, though
a few rivers may rise to near flood stage.

Highs on Sunday should reach the mid 70s to around 80 degrees before
the rain moves in. Monday will be cooler with northeast to north
winds, cloud cover, and occasional rain showers. Highs on
Monday will only reach the mid 60s to around 70s degrees.

Tuesday through Friday:

An upper trough will move onshore across the Pacific northwest, then
dig southeast across the Great Basin Tuesday afternoon. Tuesday we
will see a break in the rain chances with some insolation. Highs
will reach the lower to mid 70s.

The upper trough across the Great Basin will shift east into the
high Plains late Tuesday night. Residual Gulf moisture will advect
northward across the Plains. The combination of isentropic lift and
ascent from DCVA ahead of the H5 trough axis will cause showers and
thunderstorms to develop Tuesday morning. The scattered to numerous
showers and thunderstorms will continue into Saturday, as the lead
H5 trough amplifies across the Plains and a secondary H5 trough
digs southeast into the Plains from the Pacific northwest. It
is too early to forecast any strong to severe thunderstorms on
Friday into Friday evening. The effective shear increases but
the MLCAPE remains below 1000 J/kg the LREF ensemble cluster
mean.

Saturday: The upper air pattern transitions to a zonal flow pattern
across the northern and central Plains. A southern stream cut off
low remains stationary across the eastern Pacific, off the Baja CA
coast. there may be a few morning showers and thunderstorms during
Saturday morning but the afternoon hours look dry and
temperatures will warm into the lower to mid 80s.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1250 AM CDT Sun May 12 2024

The main impact to aviation this period will be rain moving into
terminals this afternoon with precip chances increasing into the
evening hours. This may bring some cig/vis restrictions into the
MVFR category toward the tail end of the period, and will be
something to consider adding for the next forecast. The vast
majority of guidance hangs onto VFR conditions until then. For
now, have decided to add mention of VCTS during the time period
when precip is expected to become more widespread over the area,
therefore increasing the chance of thunder impacting terminals.
However, TS could still be more scattered in nature so will
continue to evaluate the need for inclusion in TAFs with future
issuances.

&&

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

&&

$$

DISCUSSION...Gargan
AVIATION...Picha