676
FXUS63 KTOP 161921
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
221 PM CDT Fri Aug 16 2024

.KEY MESSAGES...

- Showers and storms may persist across east central Kansas this
  evening.

- There is a small chance (10 to 20 percent) for precipitation
  Saturday night into Sunday night.

- Relatively quiet weather is forecast for next week with mild
  temperatures continuing.

&&

.DISCUSSION...
Issued at 221 PM CDT Fri Aug 16 2024

19Z water vapor imagery showed a broad upper level ridge across
the southwestern U.S. with the mean westerlies remaining across
the northern tier of the country. A closed upper low was noted
over northern WI, a shortwave trough lifting north through the
northern Rockies and another upper trough off the coast of the
Pacific Northwest. Surface obs had a low pressure system just
west of the Great Lakes with weak surface ridging extending from
the northern plains into central KS. An area of showers and
thunderstorms that were ongoing over northwestern KS this
morning have moved into central KS within a warm air advection
regime.

Mid level warm air advection is progged to persist through much of
the night tonight into eastern KS. Because of this will keep a
chance POP going in spite of the lack of convection from the CAMs.
It may just be the current shower activity festering through the
evening. But the NAM forecast soundings show potentially some
elevated instability for renewed convection this evening as the low
level jet increases over the southern plains. There isn`t a lot of
cold air advection with the surface ridge so lows tonight are
expected to be in the middle 60s.

Models show for Saturday through next week an amplifying ridge
building over the central Rockies with the potential for
disturbances to crest the ridge and move over northeast KS. Perhaps
a subtle shortwave comes across the area on Sunday. Lift is better
seen on isentropic surfaces with mid level warm air advection
redeveloping late Saturday night and through the day Sunday. The NBM
generally has POPs less than 20 percent which may be a little
underdone given the similar prog from the NAM and GFS. If later
versions of the blend continue to keep POPs low, we may need to
adjust chances a little higher. After Sunday the predictability
of these shortwave details gets lower. So there isn`t a lot to
change from the blend which has some slight chances Tuesday
night.

Temps next week are forecast to be in the 80s which would generally
be a little below normal. This looks to be influenced in large part
by the 00Z ECMWF which maintains a stronger surface ridge over
eastern KS through mid-week. Think if the forecast is going to need
adjustment it may be towards a warmer forecast given the amplitude
of the upper ridge. For now the GFS which is notorious for having a
warm bias, shows the surface ridge breaking down sooner so have not
made significant changes to the forecast.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1149 AM CDT Fri Aug 16 2024

A warm air advection pattern may allow for scattered SHRA this
afternoon, but forecast soundings keep inhibition to surface
based storms. The CAMs are mixed in terms of whether SHRA will
impact the terminals. With storms out west, will keep a mention
of SHRA and VCTS but expect the more intense storms to remain
south of the terminals. VFR conditions should prevail unless a
SHRA passes overhead. Lingering cloud cover tonight raises
doubts about ground fog formation so will let later shifts
monitor trends.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters