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afdtop

Area forecast discussion
National Weather Service Topeka Kansas
534 PM CST Tue Nov 19 2019

..update to aviation forecast discussion...

Short term...(this evening through thursday)
issued at 301 PM CST Tue Nov 19 2019

A few bands of high clouds were moving through eastern Kansas this
afternoon in modest isentropic upglide between an upper ridge
over The Rockies and a surface ridge along the Kansas/Missouri
border. Water vapor imagery clearly shows two upper lows along the
California and baja coasts. Gusty south winds were noted from
southwest Kansas into southwest Texas with 50 f dewpoints along
Interstate 10.

Some periods of high cloud should continue to be the case tonight
into early Wednesday. An increasing pressure gradient brings winds
to the southeast to south under an overnight/early Wednesday low-
level jet of around 50 knots and will likely be enough to keep
temperatures fairly steady during this period. Mixing into the
warm air into early afternoon Wednesday should again bring
temperatures back into the 60s though a much windier and cloudier
daytime period is anticipated with increasing potential for
showers and a few thunderstorms in the afternoon and overnight as
the baja wave quickly moves through and dewpoints push into the
50s. With precipitable water values near 1.5 inches late
Wednesday (near record values for the date), precip chances are
quite high, though am reluctant to go beyond 90% given the
expected showery nature of the precipitation. Evening conditions
should remain quite mild though windy in the warm sector with the
passage of a modified cold front in the overnight hours dropping
temperatures into the 40s and lower 50s with steady temps through
much of Thursday via moderate cold air advection and some lingering cloud.

Long term...(thursday night through tuesday)
issued at 301 PM CST Tue Nov 19 2019

Guidance is similar with the California wave moving east into The
Four Corners area Thursday night while another modest low forms to
its east along the Colorado/Kansas border. The strength and impact
of the secondary low remain quit variable but a rather dry lower
troposphere is the rule as the weak surface anticyclone remains in
place. Given this and the confluent upper flow, it still appears
at most a modest precip event could occur with chance pops still
in order Thursday night into Friday evening with temperature
profiles supporting wintry precip phases.

The weekend periods feature modifying temperatures under zonal
flow aloft as another upper low develops off the southwest Continental U.S.
Coast. There continues to be decent agreement in an upper wave
digging southeast into The Rockies Monday into Monday night and
swinging into the plains around Tuesday. The interaction of this
wave with the cutoff low is one complicating factor but
precipitation chances do return with this system. Have kept most
precip as liquid at this point but more phases are certainly
possible.

&&

Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 528 PM CST Tue Nov 19 2019

VFR continues through late afternoon Thursday before increasing
stratus west to east brings categories down to MVFR. Main concern
overnight is the low level wind shear as a strong low level jet develops near 1
kft. Winds aloft are stronger this evening with speeds up to 50
kts from the south aft 04z at kmhk and 06z at ktop/kfoe. Some
uncertainty with timing of the MVFR stratus thereafter,
especially at kmhk where models vary on time of arrival. Coverage
of showers being scattered coupled with good model consistency
lead to a prevailing showers mention. Confidence, however, in
thunder impacting sites is low at this time.

&&



Top watches/warnings/advisories...
none.
&&

$$

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