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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
304 PM CST sun Nov 29 2015

issued at 302 PM CST sun Nov 29 2015

Light rain showers did in fact spread north over our
southern counties early this past morning...and as expected...the
marginally cold temperatures did support a brief window of freezing
rain...but no reports of significantly slick roads were reported as
the ice formation mainly occurred on untreated sidewalks and
elevated surfaces like cars and fencing. This is important to
note...since a similar event is possible tonight.

Light showers continue to spread northeast from Missouri today...and
analysis shows at least some branch of the moist plume veered into
the Ohio Valley will interact with the upper low as is moves up over
Iowa and Minnesota. Temperatures as of 2 PM are in the middle to upper
30s over western Illinois and Iowa...all of which is covered by
clouds. This again will set the stage for a marginal environment for
any freezing rainfall.


Short term...(this evening through monday)
issued at 302 PM CST sun Nov 29 2015

Warm advection will continue to
assist saturation over the region tonight...with ascent increasing
ahead of the approaching upper low. The main thrust of lift seems
to come through in two this evening...and another
towards middle day Monday. The wave this evening will fight to
saturate as it moves northeast...thus quantitative precipitation forecast should be rather
light...under 0.15 in most cases. The continuous coverage of
opaque middle clouds and dewpoints slowly increasing to around 30 to
35...will help keep our temperatures nearly isothermal...near 35
most of tonight. The northwest will see the best potential for
spotty freezing rain mixed in with the light rain...and we will
maintain some mention there. The hazard of icy roads seems to be a
low threat tonight given the marginal temperatures and for
now...will hold off on any advisory. This past morning...pavement
temperatures in southeast Iowa were in the middle 30s...which likely
abated any problems on highways...and we expect the Road
temperatures tonight to be similar.

Warm advection will continue to pump temperatures up through middle 30s
to lower 40s Monday...ending any localized freezing rain threat
northwest before dawn. Rainfall will be intermittent Monday...but
the best coverage appears to be in the late morning through
afternoon...where we will use categorical probability of precipitation for light rain.
Afternoon quantitative precipitation forecast appears to be around 0.25 or less...resulting in
amounts totaling 0.10 to 0.50 through 00z Tuesday.


Long term...(monday night through sunday)
issued at 302 PM CST sun Nov 29 2015

Forecast focus on storm system early in the week then dry with
temperatures near to above normal the remainder of the extended.

Monday night...with the storm system tracking somewhat farther west
than earlier model runs indicated this will keep the dvn County Warning Area on the
warmer side longer. Therefore...I have removed the mention of sleet
and snow for Monday night...keeping it all rain. By the time
temperatures get to freezing early Tuesday the rain will mix with or
change to snow in our far northwest counties. After midnight Monday night
the deeper moisture lifts well to the north of the County Warning Area as a dry slot
works it's way northeast across the area. Rainfall amounts will be
less than 2 tenths of an inch.

Tuesday and Tuesday night...the occluded system will track slowly
eastward across the Midwest with chilly temperatures and some very
light snow showers or flurries. Moisture will be limited so any
accumulations should be less than one-half inch and confined
primarily to our northern counties. Maximum temperatures on Tuesday
should range from the middle 30s north to the lower 40s south.

Wednesday through Sunday...generally a split flow which will keepa
rather quiet pattern for the dvn County Warning Area. Dry weather is expected with
temperatures trending above normal as the week progresses and into
next weekend.



Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1114 am CST sun Nov 29 2015

A storm system approaching Iowa from the Southern Plains will
continue to spread mainly middle level clouds...and light showers
over eastern Iowa and northwest Illinois through middle day Monday.
With temperatures holding between 33 and 40 today...this should
not be a problem for aviation interests through sunset. The dry
air should also keep visibilities at or above 6 miles in dry
weather and in showers through tonight. The widespread rain and
snow will likely lift through central Iowa tonight...but eastern
Iowa will see increasing coverage of mainly light rain especially
after 00z tonight. Ceilings should be mainly 3500 feet or higher...but
I have trended downward to MVFR later tonight as the forcing for
rain grows stronger. Some spotty freezing rain is possible toward
morning in locations northwest of Cid...thus that is the only taf
with freezing rain as a weather type. This will be watched carefully to see
if temperatures warm enough to alleviate that threat.


Dvn watches/warnings/advisories...


short term...Ervin
long term...haase

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