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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
1218 am CDT Sat Aug 23 2014

Synopsis...
issued at 235 PM CDT Friday Aug 22 2014

The ring of fire is well established today...as hot and humid high
pressure controls the deep south through central Missouri...and
periodic thunderstorm clusters roll slowly east from northeast
Kansas through Iowa and down through Indiana and West Virginia.
Temperatures are now pushing into the lower end of advisory criteria
this afternoon in our west. It is no doubt a hot and sticky day
despite our current temperatures in the middle 80s. Dewpoints are
solidly middle 70s.
Ervin

&&

Short term...(this evening through saturday)
issued at 235 PM CDT Friday Aug 22 2014

A transition from storms to heat is on tap Saturday...but our focus
will be on storms in this issuance as they are the more immediate
threat. While surface based storms are forming in many
locations...there is currently a line of storms from Des
Moines...eastward to just west of Iowa City. These are tied to the
850 mb front...and found in the axis of highest precipitable water moisture.
While wind flow is currently weak along this front...convergence is
forecast to increase later tonight...as it had each of the past 4
nights. This should place our County Warning Area into a favorable place for
training storms...with a slowly growing threat for flash flooding.
Metropolitan areas...will certainly need to be watched most carefully...as
precipitable water of 2.2 inches combine with uncapped 4000 to 5000 j/kg cape.
That/S a lot of energy to use up in narrow swaths of storms!

Saturday should see the boundary and remaining convection lift
northeast...with highs in the upper 80s northeast to 93 to 94
southwest. Dewpoints in the lower to middle 70s will boost heat index
readings to 95 to 103 during the afternoon. An advisory is likely
to be needed for this...but with storms in the short term...will
leave this for the next shift overnight....as the onset of advisory
levels should not be until afternoon Saturday...and there remains some
threat for debris clouds Saturday as well.

Ervin

Long term...(saturday night through friday)
issued at 235 PM CDT Friday Aug 22 2014

Sunday...well...that ones pretty obvious for heat headlines...as the
upper high becomes very amplified over our County Warning Area. Highs in the lower
to middle 90s are possible. Heat indexes of 100 to 105 are likely.

From out of The Frying Pan into the fire we go! Monday night
through Thursday...the European model (ecmwf) and GFS both show a slow moving
moisture and cape rich frontal passage...with rounds of thunderstorms with
possible heavy rainfall and severe. Probability of precipitation are placed accordingly on
many days.

Friday models are quite varied from a closed upper low to a high
behind the slow moving front. Either way...cooler weather is
forecast both Thursday and Friday with highs in the 70s.

Ervin

&&

Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1119 PM CDT Friday Aug 22 2014

Overnight thunderstorms most likely at kcid based on recent radar
trends. Condfidence low in timing/coverage at other taf sites.
Hi-res models suggest potential for a complex moving into the
forecast area from the west after 12z...and have this covered with
morning thunderstorms in the vicinity groups at kbrl/kcid/kmli. IFR fog/stratus favored at
kdbq during the early morning provided there is enough clearing.

&&

Dvn watches/warnings/advisories...
Iowa...none.
Illinois...none.
MO...none.
&&

$$

Synopsis...Ervin
short term...Ervin
long term...Ervin
aviation...rp Kinney

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