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Area forecast discussion 
National Weather Service quadrant cities Iowa Illinois
551 am CST Sat Nov 28 2015

..updated aviation discussion...

issued at 345 am CST Sat Nov 28 2015

Coldest surface temperatures in the Midwest at this time are
underneath a surface high over SC Minnesota/southeast South Dakota/northwest Iowa.
In this region...temperatures are in the upper single digits to lower
teens. Locally over east Iowa/west Illinois/NE Missouri scattered-broken clouds
and light northerly winds have held temperatures up into the upper
20s/lower 30s for most areas. Although where some clearing has
occurred along and north of Highway 20...temperatures have fallen into
the lower to middle 20s.


Short term...(today and tonight)
issued at 345 am CST Sat Nov 28 2015

Today...quiet weather is forecast. The surface high positioned across
the upper Mississippi Valley will not move much through the day.
Therefore...the cool northerly flow will continue at the surface.
Even though the air is becoming quite dry between 950-800mb...mid-
level warm air advection via westerly flow atop the temperature inversion should
maintain at least middle-level broken sky cover through the day. Areas
along and north of a Vinton-Iowa to Mount Carroll-Illinois line
stand the best chance to have some clearing today. Highs will be a
few degrees below average...ranging from the middle 30s far north to
lower 40s over the southeast dvn County Warning Area.

Tonight...most locations will be cold and dry. I do have a mention
of slight chances for light rain/light freezing rain mainly south
of a Keosauqua-Iowa to Burlington-Iowa line. Forecast soundings
suggest a high degree of saturation between 800-600mb coincident
with a layer of increasing isentropic lift. However...low-levels
are dry and will be difficult to saturate. Forecast lows are in
the lower 20s far north to lower 30s far south. Uttech

Long term...(sunday through friday)
issued at 345 am CST Sat Nov 28 2015

Precipitation timing/type/coverage late Sunday through Tuesday...and Hydro
concerns are the main focus of the long term period.

On Sunday...there may be some very light rain during the
day...possibly freezing rain early...across the far south...but the
more favorable forcing is expected to arrive Sunday night into
Monday. Have continued chance probability of precipitation southwest for light rain or a
light mix. The main precipitation will occur Monday and Monday night
as the surface low and upper diffluent flow move through the region.
There are still considerable differences among the latest synoptic
scale models regarding the evolution of this system...lending poor
confidence two days out in details such as snowfall accumulation and
freezing rain amounts. Overall quantitative precipitation forecast amounts should be generally in
the 0.25 to 0.50 inch range. There is some potential for a several
hour window of freezing rain/sleet...mainly early Monday along/north
of I-80...possibly enough to cause some travel issues.
However...confidence remains very low for specific
amounts...timing...and impacts. Have stayed close to wpc guidance
for snowfall with perhaps an inch or two across the northwest
counties Monday night into Tuesday. As the system heads northeast
Tuesday...lingering light snow or a rain/snow mix will be favored
across the north before tapering off Tuesday night. Wednesday
through Friday...expect a gradual warming trend with dry


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 544 am CST Sat Nov 28 2015

VFR conditions will continue through this taf period. Low-level
dry air advection has caused the lower ceilings to become few to scattered
in coverage. Broken middle-level clouds near 10 kft above ground level will last
through tonight and will continue to stream in from the west-
southwest. No precipitation is forecast into early Sunday
morning. Uttech.


issued at 345 am CST Sat Nov 28 2015

An active Hydro situation continues following the latest widespread
moderate to heavy rainfall on top of fairly saturated soils. Flood
warnings continue over parts of the Iowa river well as at
DeWitt...St. Francisville...Joslin...and Sigourney. Additional
points could be headed above minor flood stage later tonight...and
more warnings may be forthcoming at Columbus
Junction...Oakville...and Moline. The additional quantitative precipitation forecast early this week
should not have a significant impact...although the fall in river
levels may be delayed.


Dvn watches/warnings/advisories...


short term...uttech
long term...rp Kinney
hydrology...rp Kinney

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