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

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000
FXUS63 KEAX 212005
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
305 PM CDT Thu Aug 21 2014

.SHORT TERM...(This Evening through Saturday night)
Issued at 300 PM CDT THU AUG 21 2014

Tonight through Friday morning...No wholesale changes to the
forecast in the short-term. Upper level high pressure remains
centered over the Lower Mississippi Valley, with its broad influence
reaching much of the forecast area. The pattern is fairly amplified,
with a shortwave trough approaching the Four Corners region, and a
belt of stronger upper flow stretching from the shortwave trough
into the Northern Plains. Weak ascent below H7 has helped generate
some convection along the weakness of the upper ridge from southern
Nebraska towards the Iowa/Missouri border. Little change to the
overall pattern is anticipated over the next 24 hours. The primary
forecast challenge will be to determine chances for convection
across portions of the forecast area tonight into tomorrow. Models
have hinted at sliding convection southward compared to the
frequented path observed today. Cross sections show the
aforementioned weak ascent to persist and move southward overnight,
although models diverge on the southern extent. A notable nocturnal
increase in wind speeds between 1-4kft are expected, with winds
gradually veering during the night, perhaps limiting aggressive
southward convective growth. Current forecast for convection
reflects a roughly 50 mile southward shift compared to areas that
noted the most frequent precipitation today. Areas along and north
of Highway 36 have the highest probability for overnight and Friday
morning showers/thunderstorms, with a sharp drop off in
probabilities south of that line.

Friday afternoon through Saturday night...The shortwave trough lifts
into the central and northern Plains during this period, but little
in the way of height falls are noted for our forecast area. Hot
afternoon temperatures will continue, with similar conditions
anticipated on Friday as today. That said, will continue the heat
advisory as similar heat index values between 100 and 105 are
expected Friday afternoon, assuming convective cloud debris from
morning storms can clear with sufficient time for strong insolation.
Models have been persistent in mixing the surface dewpoints more
aggressively on Saturday, and while it may not be as aggressive as
models indicate, the lower Td will allow for heat index values to
fall below 100 for much of the afternoon hours. Therefore unless
forecast conditions warrant, no plans currently exist to extend heat
advisory beyond Friday afternoon. Still, with afternoon temperatures
reaching the middle 90s, precautions should be taken and heat safety
rules followed. Another slight chance of thunderstorms will be
possible Friday night into Saturday morning north of Highway 36, but
most areas should remain dry during the period.

.LONG TERM...(Sunday through Thursday)
Issued at 300 PM CDT THU AUG 21 2014

Main upper ridge axis shifts eastward by Sunday as an upper level
trough moves along the US/Canada border. Warm mid-level temperatures
are expected continue to inhibit convective development for much of the
early part of the week.

Latest ECMWF run appears to be coming into agreement with GFS
regarding the medium range forecast for the early-middle part of
next week.  Still some questions regarding timing and run to run
consistency however it does appear that a surface boundary will work
south into the region by Wednesday of next week.  This feature
should bring an end to the above normal temperatures along with an
increase in the threat for precipitation.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1214 PM CDT THU AUG 21 2014

VFR conditions expected through the period. Current gusty southerly
winds will decrease in speed by sunset. Some chance of convection
nearing STJ overnight, with lesser chances as far south as MCI/MKC.
Otherwise, outside of a few diurnally-driven cumulus, a few periods
of mid-level cloud cover is expected.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 8 PM CDT Friday FOR KSZ025-057-060-102>105.

MO...HEAT ADVISORY until 8 PM CDT Friday FOR MOZ001>006-011>015-
     020>023-028>033-037>040-043>046-053-054.

&&

$$

SHORT TERM...Blair
LONG TERM...Mitchell
AVIATION...Blair






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