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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
330 am CDT Wednesday Oct 7 2015

issued at 301 am CDT Wednesday Oct 7 2015

At 2 am CDT...region under partly to mostly cloudy skies of middle
level clouds with a very weak wind shift line passing south.
Trends suggest passage will allow for some clearing skies later
today as winds shift to the north most areas. Upstream analysis
indicates short wave over British Columbia on track to arrive late
Thursday with vorticity maximum track to north of area for best forcing.
This with marginal moisture suggest limited risk of significant
rains...if at all.


Short term...(today and tonight)
issued at 301 am CDT Wednesday Oct 7 2015

Short term forecast confidence assessment...poor or below average. Main
issue is clouds and wind shift line suggestive of cooler temperatures
risk today for highs. If clouds are slow to clear and slightly cooler
air does arrive...highs may be 3 degrees or so too high for day shift
to monitor.

Today...decreasing clouds expected...especially north 1/2 to 2/3 of
the area by middle day. Highs of 71 to 77 are based on mostly sunny skies
in middle to late afternoon. Local tools suggest highs could be 3 to 4
degrees cooler many laces with more clouds and a bit stronger north
wind bringing in cooler air. Otherwise...another nice October day.

Tonight...partly cloudy skies and winds shifting to the south ahead
of digging upper wave diving southeast from the Dakotas. Most locations should
see lows of 55 to 60 degrees with clouds possibly keeping mins closer
to 60f in many locations.

Long term...(thursday through tuesday)
issued at 301 am CDT Wednesday Oct 7 2015

Forecast focus on rain chances on Thursday with the remainder of the
extended dry with above normal temperatures for the most part.

Thursday and Thursday night...GFS/ECMWF indicated upper level trough
moving through the upper Midwest with a trailing cold front moving
across the County Warning Area. Forcing looks better to our north but in the dvn County Warning Area
the forcing and deep layer shear is weak. As a result the models the
past several runs have also indicated less quantitative precipitation forecast with each run. The
main time frame for the bulk of the showers appears to be during the
afternoon and probability of precipitation reflect this...while maintaining the 40-60
percent range. Forecast soundings indicate sbcapes of at or below 1000 j/kg
and showalters are -1 which indicates marginal instability. I will
maintain the isolated thunderstorms in the grids but mainly this is
scattered showers. Storm Prediction Center also has the County Warning Area in a marginal severe risk
but with forcing and shear on the weak side there seems to be a low
risk of large hail. If any hail does occur the time around peak
heating seems to be the window of opportunity. Rainfall amounts of
less than 1/4 inch will be common but may be somewhat higher in any
storms. Maximum temperatures will be in the middle 70s to lower 80s as
the cold front will not be arriving until late in the afternoon.

Friday through Saturday...northwest flow aloft and surface high
pressure will bring a delightful fall airmass to the region. Maximum
temperatures will be in the 60s with lows dipping into the 40s early
Saturday morning.

Sunday through Tuesday...zonal flow briefly returns on Sunday with
afternoon temperatures rebounding into the 70s. GFS/European model (ecmwf) have
backed off on the heat for Monday as a strong short wave and cold
front arrive already Monday morning. This would keep highs in the
70s for Monday and Tuesday. Operational models also indicate a dry
frontal passage on Monday.


Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 1145 PM CDT Tuesday Oct 6 2015

VFR conditions are expected through 09z/07 as high pressure moves
across the area. The light winds and any clearing should allow
patchy MVFR conditions to develop that may become a bit more
widespread around sunrise. All taf sites have MVFR conditions
developing prior to sunrise with only kbrl expecting any IFR
conditions. After sunrise Wednesday...any MVFR/IFR conditions will
slowly improve to VFR.


Dvn watches/warnings/advisories...



short term...Nichols
long term...haase

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