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fxus63 kdvn 221913 

Area forecast discussion
National Weather Service Quad Cities Iowa Illinois
213 PM CDT sun Sep 22 2019

issued at 159 PM CDT sun Sep 22 2019

The circulation which are likely the remnant of Imelda, are
moving through our southern County Warning Area as of 2 PM. This will be the back
edge of the persistent light to moderate rains we've seen the
past two days. The rates never really got very heavy in this
activity, thus, the flash flood risk seems not to be
materializing, but none the less, a 1 to 3 inch event over 2 days
has occurred.


Short term...(this evening through monday)
issued at 159 PM CDT sun Sep 22 2019

As rains end from southwest to northeast, we will clear the Flash
Flood Watch this afternoon and evening. A distance/speed tool on
the radar loop shows the event backside reaching the Quad Cities
by 4 PM. Thus, the evening will be mainly a scattered convection
to dry evening. The cold front will provide some threat for
storms, but these should be progressive and not a widespread

There will be good chance for clearing later tonight, with
dry advection and radiational cooling dropping lows to the lower
to mid 50s. A dry and pleasant day in the lower to mid 70s is
expected Monday.

Long term...(monday night through sunday)
issued at 159 PM CDT sun Sep 22 2019

Monday night and Tuesday, more Fall like weather is expected this
week with much lower humidity and cooler temperatures. 12z Sunday
run of the GFS/European model (ecmwf) build an upper level ridge over the center of
the country as a deep trof develops over the Desert Southwest and a
upper closed low moves northeast to near Quebec. Surface high
pressure will build into the Mississippi and Ohio River valleys
bringing mainly clear skies. Low temperatures Monday night will be
in the mid 50s with high temperatures on Tuesday in the mid 70s.

Tuesday night and Wednesday, a short wave trof will push through the
quasi-zonal/northwest flow aloft. A surface cold front associated
with this trof will move across the forecast area bringing a chance
of showers and thunderstorms Tuesday night into Wednesday. Skies
will clear Wednesday evening after the front moves east into the
Ohio Valley. Over night low temperatures on Tuesday night will be
around 60 with daytime highs on Wednesday in the mid 70s.

Thursday, surface high pressure will once again build into the
center of the country under a northwest flow aloft. Skies should be
mainly sunny. Daytime high temperatures will be in the mid 70s with
overnight lows in the mid 50s

Friday into next weekend, the weather will be unsettled late in the
week as a shortwave trof, ejects out of the trof/close upper low
over the Desert Southwest, and moves toward the mid Mississippi
Valley. This system will bring a chance of rain Friday into
next weekend.


Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1223 PM CDT sun Sep 22 2019

Variable cigs exist in a general IFR to MVFR environment ahead of
a cold front in central Iowa. Widespread rains will continue,
heavy at times, through late afternoon, before the cold front
effectively shuts this down. Visibilities will range from 1 to 4
miles in rain then should improve to VFR by 00z, with cigs
climbing to VFR by around 00-03z tonight. Northwest winds of 10 to
15 kts are expected behind the front with dry conditions after


Hydrology... issued at 1230 PM CDT sun Sep 22 2019

While flash flooding has not yet resulted from the significant
rainfall of 1 to 3 inches in this two day event, the widespread
rain is causing New River forecast rises over flood stage or to
moderate flood stage on several river basins.

The Mississippi is seeing rises due to routed flow, and forecast
quantitative precipitation forecast in the day 1. Thus far, that quantitative precipitation forecast seems over forecast and run
off may be overcalculated due to the slow rate of rain accrual.
Never the less, minor flooding is now forecast from Camanche
downstream through Burlington. A watch has been issued for
Camanche due to a chance run off is over forecast, and the
forecast for Rock Island has been adjusted (ncrfc coordinated), to
just under 16 feet for this same reason.

The rock and Pecatonica are forecast to see sharp rises to
moderate flooding. Warnings are out, but these are not
particularly high confidence crests due to the possibly over
estimated run off of the "slow rain".


Dvn watches/warnings/advisories...
Iowa...Flash Flood Watch until 1 am CDT Monday for Benton-Buchanan-
Cedar-Clinton-Delaware-Des Moines-Dubuque-Henry Iowa-Iowa-
Muscatine-Scott-Van Buren-Washington.

Illinois...Flash Flood Watch until 1 am CDT Monday for Bureau-Carroll-
Hancock-Henderson-Henry Illinois-Jo Daviess-McDonough-Mercer-
Putnam-Rock Island-Stephenson-Warren-Whiteside.

MO...Flash Flood Watch until 1 am CDT Monday for Clark-Scotland.




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