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FXUS63 KTOP 201121
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
621 AM CDT Wed May 20 2026

.KEY MESSAGES...

- Cool temperatures through the workweek give way to a warming and a
  mainly dry Memorial Day weekend - highs returning to the upper 70s
  to near 80.

- Showers with embedded thunderstorm chances Thursday into Saturday
  morning likely across two separate periods. More areawide for
  Thursday into early Friday. Friday night into early Saturday mainly
  south of I-70.

- Another Pacific trough digs into the western CONUS mid to late
  next week. Could bring another storm system to the Plains by the
  middle part of next week.

&&

.DISCUSSION...
Issued at 454 AM CDT Wed May 20 2026

Surface high pressure holds firm across the central Plains through
Wednesday as a modified Canadian air mass maintains cool and dry
conditions. With quality return flow yet to develop, highs will
struggle to reach the upper 60s as the stable air mass keeps
temperatures well below normal for late May.

The first precipitation chance comes into Thursday as isentropic
ascent develops along the 295-300K surface ahead of a shortwave
trough emerging from the Intermountain West. Southerly flow returning
through the H850 level supports a deepening moisture profile with
precipitable water values near the 75th climatological percentile for
this time of year. With a fairly deeply saturated column, generally
weaker instability favors efficient stratiform rainfall over organized
convection. Peak rainfall rates and best storm chances are expected
late Thursday into Friday morning.

A secondary window for rain and storm chances sets up Friday night into
Saturday morning as the main trough axis lifts out of the Rockies with
more focused ascent just northwest of the area. At least NAM soundings
currently indicate that modest elevated instability and marginal shear
could overlap mainly across east-central areas. Seems worth monitoring
though severe weather potential appears limited at this time.

Heights rise across the central CONUS through the weekend. Expect mainly
dry conditions for much of the weekend through Memorial Day with temperatures
climbing back above normal. Memorial Day highs reach into the middle 80s
across the area.

The next potential storm system arrives mid to late next week as another
Pacific trough digs into the western CONUS. Increasing Gulf moisture return
and a more dynamic forcing mechanism warrant close attention as the period
draws closer, though spread among the ENS, GEFS and GEPS remains wide
at this range.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 618 AM CDT Wed May 20 2026

VFR for the period with mid clouds increasing into the last half of the
period ahead of the next weather system approaching from the west.
ENE winds increase to around or just above 10kts later this morning
into the afternoon as the surface ridge shifts gradually east. Should
remain dry this period with any precipitation likely holding until
sometime during the first half of next period.

&&

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

&&

$$

DISCUSSION...Drake
AVIATION...Drake