Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 141800

Area Forecast Discussion
National Weather Service Quad Cities IA IL
100 PM CDT Fri Oct 14 2016


Issued at 238 AM CDT Fri Oct 14 2016

06Z surface data had high pressure over the Great Lakes with a weak
low in southeast Colorado. Dew points were in the 30s from the Great
Lakes into the northern Plains with 40s and higher from the Ohio
valley into the southern Plains.


.SHORT TERM...(Today and Tonight)
ISSUED AT 238 AM CDT Fri Oct 14 2016

Quiet and dry conditions will be seen today and tonight as high
pressure moves into the eastern Great Lakes. Temperatures will be
close to normal.

Low clouds in the Plains will slowly move north through central Iowa
and may get into the western third of the area prior to sunset.
After sunset, the low clouds will slowly move east through sunrise

.LONG TERM...(Saturday through Thursday)
ISSUED AT 238 AM CDT Fri Oct 14 2016

Strong warm advection with plentiful low level moisture will be
streaming northeastward at the onset of the day Saturday, likely
resulting in copious amounts of low clouds, especially over
northwestern sections of the CWA. Forcing is broad and unfocused,
but with a pronounced EML just above the stratus layer, drizzle
should be the weather type seen Saturday morning, possibly even into
early afternoon. This is most true over the northwest where the
moist layer is deepest and the cooler boundary layer exits. The
southeast half should recover to the mid to even upper 70s Saturday
under mostly cloudy skies and strong waa. Saturday evening, the
approaching front will make a push through through the area, as a
short wave aloft pushes east. This is expected to weaken the EML,
and with CAPE values of 200 to 800 forecast, combining with shear to
produce 0-1km bulk shear values of ~30 kts a low confidence forecast
for severe storms is in place(storms could be well elevated above
this layer). If the weak forcing does not break the EML, we could
just have drizzle along and behind the front, but should storms fire
they could organize to produce a wind and hail threat. If locally
backed winds could occur, a weak tornado may become possible. This
threat will be addressed in the HWO. Again, this is not a likely
severe weather threat, but one that marginally possible.

After Saturday night, a prolonged dry and mild period is in store,
as the main energetic frontal zone sets up north of Iowa, resulting
in sustained broad warm advection from Sunday through Tuesday. Highs
in the 70s and 80s are expected, with reasonably high confidence as
there is no moisture convergence expected over the CWA to bring
widespread cloud cover forecast. The forecast does bring a cold
front down Tuesday night in the model blend, along with another
rather strong capping inversion with it. Thus, a dry forecast
continues through Friday, with cooler temperatures at the end of the
work week.


.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
ISSUED AT 1240 PM CDT Fri Oct 14 2016

Main challenge will be timing MVFR stratocu deck from the west at
the TAF sites, with CID and possibly BRL being the first to get
under the deck this afternoon, and DBQ/MLI tonight. South to
southeast sfc winds this afternoon gusting to 20 KTs where the sun
lasts the longest or on edge of incoming cloud deck. Some IFR
decks possible under brunt of the cloud deck overnight into early
Sat morning, with 4-6SM VSBY around sunrise. Winds overnight to
maintain from the south at 8-12 KTs. With southwesterly winds at
30+ KTs projected aloft at around 2000 FT AGL toward 12z Sat, not
that far off of LLVL wind shear set up. Low MVFR cloud deck
expected for much of Sat morning with southerly SFC winds picking
up to 10-20 KTs by late morning.     ..12..




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