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Area forecast discussion 
National Weather Service Des Moines Iowa
538 PM CST Wednesday Jan 28 2015

Short term /tonight/...
issued at 323 PM CST Wednesday Jan 28 2015

Low pressure over eastern Nebraska will move east and pass east
of the County Warning Area by later tonight. Strong northwesterly winds will overspread the
state tonight as the isallobaric couplet moves through. Will
begin with a Wind Advisory over the west part of the County Warning Area around
06z...with it reaching the eastern part before 11z. Precipitation will be
limited with limited moisture...but to expect some light precipitation
over the northeast...with patchy drizzle over the central
counties. Feel the drizzle threat will end before the sub-
freezing temperatures get into the central counties and did not play with
any freezing precipitation other than the northeast. Even so...do not
expect there to be enough to cause major issues.

Long term /Thursday through Wednesday/...
issued at 323 PM CST Wednesday Jan 28 2015

Model soundings continue to indicate low end advisory gust
potential through middle morning Thursday with 42-48kts at top of
mixed layer in forecast soundings in much of central Iowa.
However...the biggest push of cold air and strongest winds off the
surface will occur near 12z with winds weakening slowly through
the day. With the potential gusts lowering through the morning and
a gradual decline in sustained winds...will let the advisory go at
15z. Clouds also look to remain in place for much of the morning
although drying in the soundings occurs by afternoon with some
partly sunny conditions after midday in many locations.

Focus really then shifts to the weekend system and associated
precipitation potential. 00z/06z model runs were extremely bullish
with this system in regards to heavy precipitation this weekend.
The concern with this system is the strength of the northern
system and the phasing with large upper low in the southwestern
United States. The older runs were stronger with this northern
system and with the subsequent phasing as well. This pulled much
more moisture northward along and inverted trough and produced a
large amount of snowfall across Iowa. In contrast...the current
12z runs have a quicker northern wave with little phasing and
subsequently a much drier solution in Iowa. There still exists a
large spread in GFS ensemble members and therefore uncertainty
remains high. Have cut back on probability of precipitation substantially during the day
Saturday and kept the highest probability of precipitation in the south and east on
Saturday night into Sunday. At this point...light accumulations
are anticipated before the snow ends on Sunday. Thereafter...much
colder air overspread the state with readings below normal into
next week. There will also be low chances for probability of precipitation returning from
time to time as weak system pass through the fast northwest flow.

&&

Aviation...29/00z
issued at 538 PM CST Wednesday Jan 28 2015

Cold frontal passage overnight will bring strong and gusty northwest
winds that will continue Thursday. A period of widespread IFR ceilings
also anticipated overnight with some visibility restrictions due to fog.
Ceilings should gradually lift to MVFR by the afternoon.

&&

Dmx watches/warnings/advisories...
Wind Advisory from 4 am to 9 am CST Thursday for Butler-Cerro
Gordo-Clarke-Decatur-Franklin-Grundy-Hardin-Jasper-Lucas-Madison-
Marion-Marshall-Polk-Ringgold-story-Union-Warren-Worth.

Wind Advisory from midnight tonight to 9 am CST Thursday for
Adair-Adams-Audubon-Boone-Calhoun-Carroll-Cass-Crawford-Dallas-
Emmet-Greene-Guthrie-Hamilton-Hancock-Humboldt-Kossuth-Palo Alto-
Pocahontas-SAC-Taylor-Webster-Winnebago-Wright.

&&

$$

Short term...MS
long term...cogil
aviation...donavon

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