Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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FXUS63 KEAX 160826
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
326 AM CDT Fri Jun 16 2017

.Discussion...
Issued at 326 AM CDT FRI JUN 16 2017

Several short term challenges with continued nocturnal convection
and increasing heat/humidity this weekend. For today, expecting
current cloud cover to retreat to the southeast throughout the
morning, allowing temperatures to climb back into the 90s by this
afternoon. Dewpoints will be similar to yesterday as a weak
frontal boundary settles north of the CWA and allows moisture to
surge back into the region in the wake of last night`s storms,
which will result in heat indices near 100 during the afternoon.
In addition, surface heating will steepen low-level lapse rates
and result in another afternoon of SBCAPE in the 3000-4000+ J/kg
range; however, a capping inversion should hold off convective
initiation during the afternoon and evening across the forecast
area.

A weak wave riding in on the nose of a jet streak across SD/NE
will override the stalled boundary, and is expected to provide
sufficient lift to break through the weaker cap across central NE
during the afternoon or early evening. Although storm coverage may
be limited initially, northwest-southeast oriented shear vectors
will steer convection into the juicy warm sector across southern
NE/IA and into KS/MO, allowing for upscale growth during the
evening and overnight hours. Deep layer shear will again top out
around 30-35 kts, but the further-north location of DCI and
orientation of the shear vector should promote a stronger, more
organized system across at least northern portions of the CWA
before the cold pool grows and has the potential to outrun the
developing system. Storm bases look a bit high for tornado
potential and a bit of a weakness in the wind profile will persist
between 700-800 hPa, but sufficient DCAPE and the environment for
very tall cores could lead to a hail and wind threat when storms
are at their peak intensity.

Moisture will pool over the region on Saturday as the thermal axis
positions directly over the center of the CWA, likely resulting in
the first advisory-criteria heat of the summer. Any lingering
convection from Friday night will push out of the region by
sunrise, allowing efficient heating and preventing any real flies
in the ointment for dangerous heat to develop by afternoon. Have
elected to issue the heat advisory now to get the word out prior
to the weekend, and extra caution will need to be taken by those
with outdoor plans.

A cold front will push through the region Saturday evening through
the early overnight hours, sparking another round of storms along
the front. The pre-frontal environment will be very reminiscent
of the last several several days with high CAPE and marginal
shear, and while the front will provide some forcing, the main
shortwave trough driving the front southward will skirt north of
the CWA. The front will be very close to, if not in our CWA by the
time convection begins to develop along it, which could mean that
most of the upscale growth occurs halfway or even two-thirds of
the way through the forecast area and coverage could be rather
limited north of the MO River. Will continue to monitor trends but
currently appears the same severe threat will exist: hail and
strong downburst winds under any robust storms that develop.

A brief break from the heat, humidity, and storm chances is
expected Sunday and Monday, then ridging will redevelop over the
High Plains and bring the 90s and on-and-off storm chances back to
the region for the remainder of the forecast period.


&&

.Aviation...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1216 AM CDT FRI JUN 16 2017

Gusty southwest winds are a very near-term concern as a wake low
moves through the KC area; however, winds should die down once
this feature moves through and will return back to the SSW at 10
kts or less by 08z-09z. Midlevel clouds based above 6-10 kft will
drift off to the southeast over the next few hours, and while a
few passing showers or perhaps a rogue lightning strike are both
possible through 08z, primarily VFR conditions are expected.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

Discussion...Laflin
Aviation...Laflin



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