204
FXUS63 KTOP 222341
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
641 PM CDT Thu Jun 22 2017

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Friday)
Issued at 250 PM CDT Thu Jun 22 2017

A compact MCV from early morning convection over north central
Kansas rolled along the NE/KS border this morning and brought some
isolated showers along with some mid clouds to NE KS. Meanwhile, the
outer fringes of decaying tropical cyclone Cindy began pushing into
east central/southeast Kansas in the form of a stratocu cloud deck.
Also at the surface, a weak surface cyclone was located near the
central KS/central NE border with a cold frontal boundary arching NE
and a dryline extending to the SSW. This front will slide SE in
response to an amplifying upper level trough digging SE across the
Northern Plains.

Scattered showers and thunderstorms are expected to develop along
and behind the front with adequate buoyancy and effective shear to
support strong to severe thunderstorms. Steep low-level lapse rates
will promote a wind threat while ample CAPE in the -10 to -30 C
layer will support large hail. CAMs have struggled to lock on to a
solution for convective initiation and trends over the course of the
evening and overnight, so did a broad-brushing of POPs from 00-12Z,
with a general clearing trend after 12Z from north to south.
Increased QPF values slightly above the blends given the proximity
of Cindy and the possibility of an interaction with tropical
moisture in increasing rainfall rates. Much cooler air pushes
southward for Friday behind the front with H850 temps falling to +13
C and surface temps likewise falling to the upper 70s to around 80.

.LONG TERM...(Friday night through Thursday)
Issued at 250 PM CDT Thu Jun 22 2017

Area remains under the influence of a cooler airmass Saturday,
although a late day passing wave may bring clouds across in the
afternoon, possibly a shower, but chances are low enough not to
include in the forecast at this time. Chances are a bit better on
Sunday for showers, as a secondary front pushes southward into
the state. Very little CAPE to work with and will carry showers as
a result. Rain chances through Sunday night shift to the
southwestern counties along with the boundary, then retreat back
to the north later overnight Monday night into Tuesday as the
southwesterly flow returns and lifts the front back north. Along
with it comes more instability and will reintroduce thunder into
the forecast. Another shortwave moves through the plains
Wednesday, with the next front forecast to move in on Thursday.

This pattern keeps cooler temperatures around for the weekend into
early week with highs in the upper 70s to low 80s, with a warm up
as the south winds and warm advection return late Tuesday and
into Thursday, although a faster frontal passage on Thursday would
cool highs down that day as well. Intensity of the storms late
week will depend on the amount of moisture return to the plains
ahead of the incoming systems.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 634 PM CDT Thu Jun 22 2017

For the 00Z TAFs, TS and showers slow to develop along and behind
a slow moving cold front over the next 6-12 hrs. Some guidance
suggests that CIG/VIS may reach below MVFR, but low confidence
precludes going much lower than MVFR at this point. Dry air moving
in behind the departing showers should give way to rising CIGS by
mid morning and improve through the day.

&&

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

$$

SHORT TERM...Skow
LONG TERM...67
AVIATION...Drake