FXUS63 KDVN 232317

Area Forecast Discussion
National Weather Service Quad Cities IA IL
617 PM CDT Tue Oct 23 2018


Issued at 312 PM CDT Tue Oct 23 2018

Latest sfc analysis was indicating a large ridge complex continuing
to occupy much of the northern plains over to the western GRT LKS,
while aloft an omega ridge was sliding eastward to the lee of the
Rockies and the stretch of the plains. This system to continue to
provide a fair wx pattern locally through mid week, before a
portion(or portions) of the western trof break loose and try to
migrate acrs the central CONUS by Thu night-Friday and into the
weekend for the next round of precip chances.


.SHORT TERM...(This Evening through Wednesday)
ISSUED AT 312 PM CDT Tue Oct 23 2018

Tonight...As the sfc ridge slides into the GRT LKS, it will continue
to squeeze down drier source north to northeasterly flow into the
local area through Wed morning. With this in mind under clear skies
and ongoing dry airmass rule of cooler at night/milder than most
guidance during the day, will side with the coolest of guidance or
even undercut. But ongoing low temp grids from the previous shift
already handling this and will make little change. Several upper 20s
possible especially in the normal low lying cool air drainage

Wednesday...Sfc ridge axis slated to slide eastward acrs the western
GRT LKS making for east to southeast sfc winds locally, as the upper
ridge axis migrates overhead toward the MS RVR valley. After a
chilly start to the day, expect another dry airmass rather large
diurnal swing by Wed afternoon. Will side with warmer of guidance
highs that suggest widespread mid to upper 50s, but would not be
surprised by a few 60+ degree readings like what is currently going
on acrs far eastern NE. ..12..

.LONG TERM...(Wednesday Night through next Tuesday)
ISSUED AT 312 PM CDT Tue Oct 23 2018

Long term period will begin with quiet weather and end with an
active pattern and precip chances returning to the area. Overall
pattern remains in a blocking pattern before the jet stream moves
across the area. The jet stream brings the storm track across the

Quiet weather is expected through early Friday when the first wave
moves into the central CONUS. Current trajectory of this wave will
take it south of the area. The best chances for precip on Friday
into Saturday appear to be across the central Mississippi River
valley. The current forecast has precip chances across the area for
Friday and Saturday, that said, if the current low track maintains,
it appears the chance for pops will not be in our area. After this,
models diverge. The ECMWF has a second wave Saturday and a final
wave on Sunday. The other models only have a final wave on Sunday.
If you like a wet weekend, you want the Euro to win. If you want a
dry Saturday, then you favor the other models. Overall certainty in
forecast solutions for this weekend is low. We will need more
stable run to run consistency before a better idea of this weekend
can be ascertained.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
ISSUED AT 614 PM CDT Tue Oct 23 2018

Very quiet VFR weather will continue through Wednesday evening.
Skies will be clear to mostly clear, with excellent visibility,
except for perhaps localized farm harvest dust. Winds will switch
from north to southeast through the next 24 hours, but will remain
below 5 kts, so a variable 3kt wind group has been used throughout.


Issued at 312 PM CDT Tue Oct 23 2018

Minor to Major flooding continues on several rivers in eastern Iowa
and northwest Illinois. Little appreciable rainfall is expected over
the next 7 days with just light amounts over the weekend, and river
forecasts are expected to remain relatively unchanged through the
end of the week.

The long duration of flooding on the Wapsipinicon River near De Witt
has finally ended, as the river fell below flood stage there last
night. Other forecast locations on the Iowa and Cedar Rivers
continue to show down trends/falling levels over the next several
days, with a few locations like Conesville likley to eventually drop
below flood stage during that period.

Coralville Lake Reservoir was at 710.2 feet and slowly falling this
morning. It will continue to slowly fall through the weekend,
possibly reaching 707 feet by Monday night October 29th.

On the Mississippi River, the routed flow resulting from rainfall
earlier this month upstream over portions of WI and MN that produced
a broad and lower amplitude secondary crest, is progressing through
and south of the Camanche-through Quad Cites-Muscatine stretch, thus
slowing falling river level trends should continue at most sites
through the upcoming weekend. As earlier mentioned along this
stretch, the advancing flow will mainly prolong the on-going higher
levels and flooding than what normally would occur during this drier
weather regime of the past week or so. Otherwise, falling levels
upstream has allowed the river at Dubuque to fall below flood stage
last night, with Camanche the next to go by Thursday morning.




Back to Main Forecast Discussion Page