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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
1130 am CST Wednesday Feb 10 2016

Update...
issued at 1122 am CST Wednesday Feb 10 2016

The band of light snow has shifted a bit further east since middle
morning. Very light snow is now occurring at kawg and may be
getting ready to begin at kmpz.

As a result of radar trends...the forecast has been adjusted
eastward for the snow and snow amounts. Due to the dry air in the
lower atmosphere there will still be a fairly sharp cut off
between no snow and accumulating snow. However...it does appear
that Van Buren County in Iowa...Scotland and Clark counties in
Missouri may see an inch of snow by evening.

Update issued at 931 am CST Wednesday Feb 10 2016

Adjustments have been done to the current forecast based on radar
trends and what has been implied by the rap.

It appears that the far southwest area should see anywhere from a
dusting to possibly an inch of accumulation. Scotland County
looks to have the best chance of seeing any snow accumulation.
The gradient in snowfall amounts from no snow to an inch may
occur in no more than 20 miles.

&&

Synopsis...
issued at 225 am CST Wednesday Feb 10 2016

The sky was mostly clear overnight. A northwest wind averaged 5 to
15 miles per hour. Early morning temperatures were in the single digits to
low teens...with wind chill values below zero most locations. The
coldest conditions were located along the Highway 20 corridor.

&&

Short term...(today and tonight)
issued at 225 am CST Wednesday Feb 10 2016

The main focus of the short term period is a weak clipper system
that will glance portions of the forecast area today.

In the near term...coldest wind chill values of 15 to 20 below
zero will continue early this morning along the Highway 20
corridor...not quite cold enough to warrant an advisory. Most
high resolution models keep any light snow just out of the
County Warning Area today...while synoptic models still suggest a light dusting
in the far southwest. Have cut back probability of precipitation slightly from previous
forecast and limited them mainly to the southern most 6 counties.
Any light snow should quickly move south of the area late this
afternoon or early this evening. Expect another cold day...with
highs in the low teens north to around 20 south.

For tonight...the surface ridge will nose into the area as surface
winds drop off. Expect clearing from northeast to southwest with
lows in the single digits above and below zero. At worst...wind
chills around 15 below are possible along Highway 20.

Long term...(thursday through tuesday)
issued at 225 am CST Wednesday Feb 10 2016

Thursday...near 10-15 degrees below normal. Highs in the teens north
of I-80...lower 20s to the south. Dry weather is forecast along with
partly to mostly sunny skies.

Friday...temperatures moderate a bit into the upper teens far
north...middle 20s along I-80...and near 30 f far South. West-northwest winds warm
850mb temperatures early in the day just slightly before cold air advection ramps
back up.

Precipitation...light snow chances return to the forecast area. The northwest flow
aloft will bring another Alberta clipper southeastward into the
Midwest. Probability of precipitation are only in the 20-30 percent range between midnight
Friday and noon Friday. Any snow accumulations should be very light
because this system is very weak and is moisture starved. Most areas
can expect a trace to up to a half inch.

Friday evening into Saturday morning...strong 1045mb high builds
into the upper Midwest...advecting colder temperatures into east Iowa/west
Illinois/and NE Missouri. 850mb temperatures will drop to near -20 c. Surface
temperatures will follow suit...lower single digits above and below zero
are forecast for lows...creating wind chills in the teens below
zero...but in the lower to possibly middle 20s below zero along and
north of a Cedar Rapids to Galena line.

A Wind Chill Advisory may be necessary for parts of the County Warning Area but this
event currently looks marginal as to whether the Wind Chill Advisory
criteria will be met for more than an hour or two...something to
monitor.

Saturday afternoon...current forecast high temperatures are about 20
degrees below seasonal normals...upper teens far south...middle teens
along I-80...and upper single digits over the northwest.

Sunday...SW return flow results in low-level warm air and moisture
advection and chances for precipitation...model consensus probability of precipitation have
increased into the 40-50 percent range. Thermal profiles favor
snow...but models keep the shortwave disorganized. The GFS has
the most coherent structure and steadier precipitation but nothing heavy.

Monday...signal for a significant jump in temperatures...superblend has
lower 30s north...middle 30s along I-80...and near 40 f far south. 1000-
500mb thicknesses and 850mb temperatures rise to 528-534 dam and -2 to -4c
respectfully.

Tuesday...mild and dry with highs in the 30s and 40s. Uttech

&&

Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1122 am CST Wednesday Feb 10 2016

A storm system is moving south southeast and producing a band of
snow across central Iowa into northern Missouri. In this band of
snow IFR/MVFR conditions are occurring. For most of eastern Iowa
and northern Illinois VFR conditions were prevailing. VFR
conditions are expected to continue for most of eastern Iowa and
all of northern Illinois through 00z/12 as high pressure builds
into the Midwest behind the departing storm system.

&&

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

$$

Update...08
synopsis...rp Kinney
short term...rp Kinney
long term...uttech
aviation...08

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