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

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FXUS63 KEAX 261730
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1230 PM CDT Tue Aug 26 2014

.DISCUSSION...
Issued at 347 AM CDT TUE AUG 26 2014

Today:

A stationary front can be found this morning along a (just
north of) Kirksville to St Joseph to Manhattan line. Thunderstorms
have developed north of this front across southeastern Nebraska and
southwestern Iowa in response to a strengthening southwesterly LLJ.
These storms have been progressing eastward tracking north of the
area however, they have started taking a slight jog the ESE which
would allow these storms to clip extreme northern Missouri this
morning and as such have left chance POPs across the northern CWA.
These storms will dissipate this morning but may leave some residual
clouds across the northern CWA keeping temperatures cooler across the
northern CWA with highs in the mid 80s to near 90. Further south (of
the stationary front), the heat will remain entrenched for another
day with highs in the low to mid 90s. Dewpoints will also be slightly
higher than in the past couple of days as moisture pools along and
south of the front. With expected dewpoints in the lower 70s this
afternoon, expect heat index values along and south of the Missouri
River ranging in the 100-105 range. Have left slight chance POPs in
for this afternoon across northern Missouri in the vicinity of the
surface boundary because although convergence is non-
existent...moisture pooling and instability could spark an afternoon
thunderstorm.

Tonight through Tomorrow night:

The main concern during this time frame will deal with thunderstorm
chances. Tonight another nocturnal LLJ will develop will develop and
again bring the chance for thunderstorms along and north of the
surface boundary. As such have left chance POPs in the across
northern Missouri. Wednesday will bring more cloud cover than in
previous day knocking temperatures down a few degrees into the mid
80s to lower 90s. There will be a chance for ongoing convection
during the morning hours on Wednesday however, the afternoon should
remain dry. However, thunderstorm chances will again increase
Wednesday night as yet another nocturnal LLJ gets ramped up. Again
the focus for storm looks to be across northeastern Kansas and
northwestern Missouri where chance POPs are located.

Thursday through Sunday:

The next main storm system in the form of an upper level trough will
affect the area during this time frame leading to a period of
unsettled weather. The upper level trough in question is evident on
water vapor imagery digging through Nevada this morning. An upper
level low is expected to develop in the base of the trough across
Nevada today. This will slow the system down and as such will only
move into the eastern Rockies by Thursday. This will force a cold
front into the Western Plains on Thursday as thunderstorm develop
west of the local area. Model timing has been the challenge in
previous forecasts as to when this front will move into the area.
Models have come into better agreement in recent runs and are now
depicting the front to reach into eastern Kansas late Thursday night
or Friday morning. As such thunderstorms should move into the
western CWA Thursday night and overspread the area on Friday as the
cold front stalls across eastern Kansas in response to the slowing
and weakening upper level trough. The upper level trough finally
does push through the region Saturday finally force the cold front
through the CWA continuing thunderstorm chances. By Sunday the upper
level trough will be exiting the region. There may be a few residual
showers across the eastern CWA early Sunday but otherwise conditions
should remain dry with seasonable highs in the low to mid 80s.

Monday:

Models depict another shortwave moving through the region however
the spread of timing and placement of this feature leave much to be
desired. The GFS is much faster and further south with this feature
than the EC. Given vast model difference have opted to keep what was
inherited by the initialization...which is chance POPs.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1229 PM CDT TUE AUG 26 2014

Broad upper ridging prevailing over the region this afternoon.
Despite the presence of a weak frontal boundary across northern
Missouri...fcst going forward should largely be dry for all
terminals. Main concern heading into the overnight period will be
radiational fog/low cig potential during the predawn hours. Models
continue to offer this suggestion and have offered a tempo IFR
mention at STJ...and MVFR mention at MCI after 8z. Possible caveats
may be cloud cover and wind direction...however later fcsts can
adjust based on latest trends. Winds generally from the southeast
between 5-10 kts this afternoon before going nearly calm overnight.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 7 PM CDT this evening FOR KSZ057-060-103>105.

MO...HEAT ADVISORY until 7 PM CDT this evening FOR MOZ028>033-037>040-
     043>046-053-054.

&&

$$

DISCUSSION...73
AVIATION...32






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