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Area forecast discussion 
National Weather Service Des Moines Iowa
1251 PM CDT Tuesday Oct 21 2014

Synopsis....high pressure ridge from Ontario through Iowa into Texas
will move east with flow becoming southeasterly. Frontal system will move
through The Rockies and pass through the upper Midwest Wednesday
night and Thursday.


Short term /today/...
issued at 355 am CDT Tuesday Oct 21 2014

High pressure ridge over Iowa this morning will drift to the east with
winds gradually becoming southeasterly this afternoon. Morning lows will
start out lower than yesterday. That in combination with lower 1000-
925 mb thickness values and southeasterly flow out of the high pressure ridge
will yield cooler temperatures than yesterday...especially over the northestern
zones kept highs in the upper 50s and 60s today vs the 65 to 75
degree readings of yesterday. Skies will remain mostly clear today
with no real moisture return and only weak warm air advection aloft.

Long term /tonight through Monday/...
issued at 355 am CDT Tuesday Oct 21 2014

Main focus was on rain chances Wednesday night into Thursday and
temperatures Friday through the weekend. Leaned toward the slower
European model (ecmwf) 21.00z solution with respect to to the front moving through the region middle-
week and also over the weekend as well as it was the slightly warmer
of the extended models.

Tonight through Thursday...upper level ridge moves overhead with a
surface high shifting east tonight into Wednesday allowing for some
fairly strong warm air advection aloft tomorrow ahead of next shortwave trough
ejecting out of the northern rockies. European model (ecmwf)/GFS have slowed system
down entering the forecast area but still looks to be a quick moving
system across the state. Impressive moisture transport into the
state and precipitable water values rise to 1.00 to 1.25 inches for
much of the central Iowa. This is about two Standard deviations
above normal for this time of year. Strongest forcing and deepest
moisture move across the forecast area from 03z to 12z
Thursday...with some lingering rain across the eastern sections of
the forecast through 18z Thursday. Thunderstorm potential as well as
severe potential look minimal with very limited instability
available...but anything present will be confined over southern
Iowa. Kept the thunder mentioned in this location.

Friday into Monday...upper level ridge builds into the central U.S.
By Friday with Iowa placed west of a weak surface high. Looks to be
enough mixing and warm air advection on the backside of the surface high to put maximum
temperatures into the 70s. 850mb temperatures rise to +14c to +17c
across Iowa by the afternoon. As a result...warmed maximum temperatures
up 1-3 degrees over much of the forecast area. Even stronger warm air advection and
mixing on Sunday as 850mb temperatures rise to +16 to +18c. Tweaked
maximum temperatures up Sunday as well.


issued at 1234 PM CDT Tuesday Oct 21 2014

Skies will remain VFR at sites through 10z Wednesday...followed by
low VFR. Winds will continue to shift from east-southeast towards the south
through taf period. Possibility for MVFR visibilities in the
couple of hours near 12z at all sites...especially kmcw.


Dmx watches/warnings/advisories...


Synopsis...MS Oct 14
short term...MS Oct 14
long term...klp

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