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

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000
FXUS63 KEAX 312358
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
658 PM CDT FRI JUL 31 2015

.DISCUSSION...
Issued at 319 PM CDT FRI JUL 31 2015

Storm chances across far northern Missouri will be the main concern
this weekend, mainly this evening and again Saturday evening into
Saturday night. A few storms have already begun to initiate across
eastern NE this afternoon, and a cu field continues to expand south
and east of ongoing storms, edging into the far NW corner of the
CWA. Moisture pooling in the local area and temperatures in the
upper 80s have resulted in 3000+ J/kg CAPE; however, model soundings
show a weak capping inversion lingering around 900-875 hPa that may
prevent widespread storm development. 0-6 km shear values remain
marginal at best with only about 20 kts of flow at 6 km, then winds
begin to increase dramatically above about 8 km, possibly causing
updrafts to shear off and making storm organization difficult. Above
all, the baroclinic zone supporting storm initiation continues to
weaken, and very weak surface winds indicate very little surface
focus and convergence to support CI; thus, storm coverage may be
isolated this evening. Storms will also be diurnally driven and any
southeastward progress into the rest of the CWA brings storms into a
less supportive environment, so do not expect any convection south
of the Hwy 36 corridor this evening, nor any overnight storm
activity.

Another round of storms is possible again in a similar setup
Saturday afternoon and evening, but initiation may occur a bit
further to the north where a shortwave trough will slide across
northeast Nebraska into northern Iowa. Southward sagging of any
convection or outflow boundaries could take storms into northern
Missouri after sunset, but have once again confined PoPs mainly to
the Hwy 36 corridor and northward, and taper chances back after
midnight when forcing for storms exits the region and diurnal
instability is eliminated. Better shear may support more organized
storms, but the possibility of storms staying completely north of
the CWA prevents any widespread concern for strong/severe storms.

For the remainder of the forecast area, the only real concern this
weekend will be heat as temperatures and moisture very slowly climb.
Highs in the lower 90s and dewpoints in the lower 70s will spell
heat indices maxing out around 100 most afternoons, which is not
enough for heat advisory concerns but will still be uncomfortable
for those with outdoor plans. Overnight lows will also linger in the
upper 60s to mid 70s, providing little relief during the night.
Surface winds will also remain fairly light as surface high pressure
drifts and expands east.

Storm chances continue to look a bit higher into next work week as a
slow-moving boundary drapes somewhere in the CWA and upper-level
flow flattens, supporting the transport of a few weak shortwave
troughs through the area. Models still differ a bit on the timing
and location of shortwave troughs, but storms are still possible in
almost any period with ample moisture and the surface boundary
present. Temperatures will be impacted by any clouds/precipitation
and also the eventual position of the boundary, but should generally
be a bit cooler in the majority of the CWA during the daytime hours.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 657 PM CDT FRI JUL 31 2015

VFR conditions expected at the terminals over the next 24 hours. High
pressure continues to affect the area and this should result in just
high level clouds and light winds throughout the forecast. The
exception is STJ which again may have some river valley fog.

&&

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

$$

DISCUSSION...Laflin
AVIATION...CDB



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