Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 262046
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
346 PM CDT Tue May 26 2015

.SHORT TERM...(This Evening through Wednesday)
Issued at 225 PM CDT TUE MAY 26 2015

Fcst focus is on precip chcs this evening and tomorrow.

19z sfc map shows low pressure across sw WI with a cold front
extending southwest into KS.  Another weak low center appeared to be
located across far nw MO which seems to be a reflection of a couple
of waves now moving across NE/KS border. Those are acting to produce
weak convergence across the area and along with heating and a weak
boundary I suspect we could see isolated convection late this
afternoon with some gusty winds given around 1000j/kg of cape and
unidirectional wind profile.  Additional isolated/sct convection
could also occur near the boundary later this evening as lift from
waves now across southern/western KS generate more storms across
southern KS.  As a result, we will keep low chc pops across the
south through midnight for this scenario.

Weds should be dry for the most part as weak ridging moves across
the area. The sfc front should mix back to the north bringing
dewpoints in the 60s with it by midday however it appears that the
best moisture convergence and lift will be focused across western KS
by late in the day as another upper wave emerges out of the central
Rockies.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 225 PM CDT TUE MAY 26 2015

From the period Wednesday night through Saturday morning, the
pattern continues to favor rounds of thunderstorms with warm and
humid conditions.

By Wednesday evening, the models are in good agreement concerning
the overall situation with west southwest flow aloft and surface
low pressure over the high plains of southeast Colorado and a
surface warm front into the southern plains. Thunderstorms should
develop in the upslope region during the afternoon and then move
across the plains Wednesday night. Thunderstorms should be
supported by a decent low-level jet and and moisture. It is
unclear how this will progress and at this point will forecast a
mid range POP for this potential.

The upper air pattern on Thursday and Friday is very busy. The upper
low initially over the pacific northwest drifts southeast into the
central plains by Friday evening. In the southern stream, pieces
of shortwave energy eject northeast ahead of upper low across the
southern and central plains. The airmass over eastern Kansas will
be very moist by Thursday with precipitable water values of around
1.5 inches according to both the 12 UTC GFS/NAM. With deep
moisture in place and instability, expect showers and
thunderstorms to develop with available forcing during this
period. The storms should be efficient precipitation generators
given the moisture plume.

To the north in the northern stream, a shortwave moving across the
lakes should drag a cold front south across the northern plains
and into Nebraska by Friday morning. The shortwave energy moving
into the central plains moves through Friday and Friday night and
dragging the cold front through eastern Kansas. After another
round showers and storms with this system, we should dry-out for
the the remainder of the forecast period. The combination of drier
air in association with the surface ridge and building 500 MB
heights supports a generally dry forecast which will be a welcome
relief.

Expect below normal temperatures after the frontal passage and then
rebounding by the end of the extended.


&&

.AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon)
Issued at 1209 PM CDT TUE MAY 26 2015

Expect VFR conds to prevail through the period. Only issue may be
sct -shra or isolated tsra which is possible just about anywhere
through 06z given the unstable atmosphere and proximity of the
upper system and weak boundary. Simply don`t think coverage will
be sufficient to warrant any more than vcsh at this point.


&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Omitt
LONG TERM...Johnson
AVIATION...Omitt





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