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National Weather Service Des Moines Iowa
issued by National Weather Service quadrant cities Iowa Illinois
102 PM CDT Tuesday Oct 6 2015

Update... issued at 1002 am CDT Tuesday Oct 6 2015

Quick update to mainly raise sky cover rest of this am based on
satellite and ob trends. Will continue with idea of at least some
partial clearing or dissipation of cloud cover this afternoon with
subsidence in wake of departing weak middle level shortwave. As
result... left maximum temperatures alone for now. Also... may be a few
sprinkles with weak returns on radar west and northwest of Des
Moines metropolitan... but too isolated for mention.


Short term /today/... issued at 252 am CDT Tuesday Oct 6 2015

Main forecast concern dealt with temperatures and cloud cover. Very
little flow in this air mass and middle to high cloud deck looks to be
very persistent through much of the day. Relative humidity between 800-600mb
remains greater than 80 percent until around 18-20z this afternoon
before cloud deck begins to thin out a little over the north and
east. Cloud cover looks to be more persistent in the west. Very weak
and subtle shortwave will exit the state late this morning which
should help dissipate some of the cloud deck. Went at or a slight
nudge above MOS guidance (ecs/met/mav) as they were in good
agreement for maximum temperatures today. Not overly concerned about precipitation
chances today...but to note the latest hrrr shows some light rain
over the west. Although cannot rule out some sprinkles today...low
confidence in mentioning with the high based cloud deck.

Long term /tonight through Sunday/... issued at 252 am CDT Tuesday Oct
6 2015

Few concerns for the extended. Timing of front and subsequent rain
chances the main challenge this period. The GFS/NAM continue to lead
the pack with a faster frontal transition through the area compared
to the Euro. Have trended slightly slower with the frontal passage
with showers/isolated thunder lingering into Thursday afternoon. Though
moisture will be on the increase from the southwest into the Central
Plains as the boundary nears...rainfall amounts with the lack of
concerted forcing should range in the tenths to half inch range as
the boundary moves out of the area. A push of cooler air will
accompany the boundary Thursday night into Friday. Though Friday
will be mainly dry...partly cloudy conditions will likely hold highs
in the lower 60s with upper 50s possible north. North northeast
winds will add to the cooler fall readings for the day. Gradually
through the weekend and into early next week h500 height rises and a
transition to more zonal flow will result in milder temperatures
through Sunday. A dry cool front is slated to cross the
Midwest/plains Sunday evening with a return to west northwest flow
on Monday. Cooler air is expected to arrive by Tuesday with
relatively quiet weather expected again into early next week.


Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 1250 PM CDT Tuesday Oct 6 2015

Surface cold front will sag southward into southern Iowa by
Wednesday morning. Light winds and ample low level moisture may
result in more patchy MVFR to LIFR conditions in fog and low
clouds overnight ahead of the boundary mainly south of I-80.
Kotm stands the best chance of seeing these lower conditions and
while middle clouds present some challenge given little airmass
change I forecasted similar conditions at kotm to what occurred
this am. Otherwise...generally VFR conditions will prevail with
bouts of cloudiness with bases mainly 5-10kft above ground level. Along/north of
I-80 anticipate light S/SW winds to veer to northerly tonight with
passage of the front... while light and variable winds expected


Dmx watches/warnings/advisories...


short term...podrazik
long term...rev

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