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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
651 am CDT Tuesday Sep 16 2014

Synopsis...
issued at 233 am CDT Tuesday Sep 16 2014

At 3 am CDT...surface high pressure was centered across the
Missouri River valley. A clear sky and light wind was resulting in
patchy fog across parts of eastern Iowa and northwest Illinois.
Early morning temperatures ranged from the upper 30s in the wapsi
valley to the upper 40s in the southern portion of the forecast
area.

&&

Short term...(today and tonight)
issued at 233 am CDT Tuesday Sep 16 2014

The main forecast challenge in the short term period is temperatures
today and tonight.

In the near term...patchy fog continues to develop early this
morning in areas with calm winds. A light northwest wind is
keeping fog development at Bay across the south. Patchy fog
remains in the forecast grids County Warning Area-wide until 13z. Early morning
lows are not expected to threaten the record lows for the
date...which range from 34 to 39 degrees at the four main climate
sites.

High pressure will be centered across the forecast area today
with a light wind and plenty of sunshine. The 850mb cool pocket is
expected to reside across the northern counties...with low 60s
forecast this afternoon...warming to the upper 60s south.

For tonight...surface high pressure will begin to slide east with
weak southeast flow developing. Am expecting a wider northeast to
southwest temperature gradient than suggested by consensus blend
guidance. The Freeport area looks to be the cool spot...and may
remain in the upper 30s early Wednesday morning. Any fog
development would be favored in the light winds across the far
eastern fringe of the forecast area...but confidence is low and
will not patchy fog in the forecast right now. Rp Kinney

Long term...(wednesday through next monday)
issued at 233 am CDT Tuesday Sep 16 2014

Wednesday through Friday...northwesterly middle level steering flow to
occupy much of the upper Midwest and western Great Lakes west of East
Coast l/west trough during midweek. Large low level backdoor type anticyclone
prognosticated by most 00z run medium range solutions to engulf the Great Lakes
through Thursday...with dry fetch east to Northeast Boundary layer flow
and even deeper influence keeping the County Warning Area dry through Friday am.
Convergent low level return flow to fester showers and storms off to the
south and west Wednesday and Wednesday night...with just maybe some higher level
debris clouds in the southwestern County Warning Area. Still though plenty of
insolation Wednesday and Thursday...highs in the upper 60s to lower 70s Wednesday to
moderate slightly into Thursday. Light east winds may allow for some
areas of fog to form in subtle convergent regions late Wednesday
night...but drying surface and boundary layer through then makes this
occurrence less probable. Longer range trends suggest large surface high
pressure complex to migrate eastward by weeks end as upstream ridging
presses out/flattens as it approaches in response to northern stream
upper wave onslaught/central Canadian phasing. Strengthening return
flow signals for Friday with adequate mixing in southeasterly to
southerly flow would make for widespread highs in the middle to upper
70s...with a return to the 80s possible in some locations. Do not
currently see much of a focus for precipitation to fire on in this regime
although low level moisture is starting to return as well. Maybe just an
isolated ambient airmass type shower or storm in the afternoon. The
local area probably to remain dry Friday night as well as freshly
energized westerlies light up the northern plains across to the
northern Great Lakes with convective clusters.

Saturday though next Monday...interesting signal on the medium range
solutions including the 00z GFS and European model (ecmwf) of suggesting remnants
of Odile to get drawn up in l/west phasing process across the upper
Midwest on Sat...with a possibly closed circulation/cyclone
propagating east-northeastward somewhere across the middle to upper MS
River Valley. The 00z run solutions suggest the low level circulation to
roll up along and just south of the dvn County Warning Area by Sat night...
effectively producing a heavy rain def zone type feature across at
least the southeastern third of the dvn County Warning Area Sat night into early
Sunday morning. Monsoonal moisture feed up along with it boosting
precipitable water/S to unseasonable levels again could mean 2-4+ inches of rain
in the heavier precipitation bands moving across the southern County Warning Area from late
Sat into early Sunday morning. A definite trend to watch in
upcoming solutions/model runs over the next 36-48 hours. With another
freshly established l/west trough and upper level cyclone across the Great
Lakes by early next week...will have to watch for another cool dump
down the upper MS River Valley by next Monday or Tuesday. ..12..

&&

Aviation...(for the 12z tafs through 12z Wednesday morning)
issued at 649 am CDT Tuesday Sep 16 2014

Brief periods of mainly MVFR fog will persist early this
morning...otherwise expect VFR conditions and light winds through
the taf period.

&&

Climate...
issued at 233 am CDT Tuesday Sep 16 2014

Record lows for September 16...

Moline.........37 in 1984
Cedar Rapids...34 in 1937
Dubuque........34 in 1984
Burlington.....39 in 1984

&&

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

$$

Synopsis...rp Kinney
short term...rp Kinney
long term...12
aviation...rp Kinney
climate...rp Kinney

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