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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
659 am CDT Wednesday Sep 2 2015

issued at 235 am CDT Wednesday Sep 2 2015

Warm and humid conditions are entrenched over the Midwest with a
weak disturbance producing a slowly decaying ribbon of showers and
storms over western Iowa moving slowly east. Upstream analysis
shows the remnants of this to slide across the region today. Area
temperatures are similar to last night with ranging from 68 to 73
degrees. Upper air analysis shows little change the next 36 to 48


Short term...(today and tonight)
issued at 235 am CDT Wednesday Sep 2 2015

Today...little change to forecast. Weak disturbance suggests area
highs in some places may be a degree or two less than Tuesday with
a bit more clouds. Have very low probability of precipitation far northwest and north today which
may need to be upped this am if decaying line holds together into
middle morning which often is the case. Either forcing
and heating in the daytime suggests this precipitation should end
by late morning. Next question is if convective temperature is reached
around 3 PM with this weak disturbance middle to late afternoon. Have
taken a conservative or low end on this risk since area is under
upper ridging and will pass to day shift to reassess. Area highs
should top out in the 87 to 92 degree range with heat indices
rising into the middle 90s for a few hours.

Tonight...persistence again with fair skies and lows generally in
the upper 60s to around 70f. Some patchy light fog also possible
well after midnight with very low probability of precipitation far north as weak disturbance
is suggested may skirt far NE. This is predicated on if any PM convection
fires. Key is any probability of precipitation should be spotty and generally light on amounts.

Long term...(thursday through tuesday)
issued at 235 am CDT Wednesday Sep 2 2015

Main forecast concern for the long term forecast is the next frontal
system moving through the area the beginning of next week. Recent
runs have shown run to run variability. Regardless I think it is
safe to say that there will be some precipitation producing system
affecting the County Warning Area next week.

Models have been consistent with the system entering the County Warning Area late
Sunday and overnight into the beginning of the work week. The European model (ecmwf)
is slightly faster than the GFS and as such has more quantitative precipitation forecast. Since the
front looks to be passing through the County Warning Area during the overnight
hours...the intensity of convection and precipitation will be lower than it
would be earlier like the European model (ecmwf) solution. Regardless both models
have a signal for rain and possibly heavy rain. With summertime
moisture in the area it is likely that convection will be relatively
effective rain producers. Specifics past this are too soon to

Temperatures will remain above average until this system moves through the
area. At this time temperatures should drop to near normal.


Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 650 am CDT Wednesday Sep 2 2015

Surface and upper air ridging to keep terminals fair with VFR conditions
the next 24 plus hours. Some patchy light fog possible toward sunrise
but risk too low and coverage too spotty to add to terminals at this time.


Dvn watches/warnings/advisories...


short term...Nichols
long term...Gibbs

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