032
FXUS63 KDVN 192349
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
649 PM CDT Sat Apr 19 2025

.KEY MESSAGES...

- A strong storm system will cross our area on Sunday and Sunday
  night bringing widespread rainfall and possibly a few severe
  storms south of I-80.

- Seasonal temperatures are expected this weekend with a warm
  up next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 200 PM CDT Sat Apr 19 2025

High pressure has set up across the Upper Midwest into the
Great Lakes, north of a nearly stationary front draped from the
Southern Plains into the Ohio Valley. Therefore we can expect
quiet conditions across eastern Iowa and northwest Illinois this
evening into tonight with light winds and dry conditions. An
area of low pressure organizing across north Texas into Oklahoma
will quickly pull to the north late tonight into Sunday
morning. This system will bring widespread rain to the area,
first moving into southern sections between 3 - 6 AM and then
spreading to the north through the morning to early afternoon on
Sunday.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
Issued at 200 PM CDT Sat Apr 19 2025

Sunday and Sunday night: A longwave upper-level trough is
expected to move out of the Rockies and approach our region for
Easter Sunday, becoming more negatively-tilted with time. A
potent mid-level vort max should pivot through the area,
supporting large-scale forcing for ascent. An attendant surface
low pressure system will lift northward from the southern Great
Plains towards eastern Iowa by Sunday evening. This will support
widespread rain (80-100% chance) and a few thunderstorms. Heavy
downpours at times will be the main story with this system, as
instability will be more limited. However, abundant moisture is
expected, with Pwat values progged around 1 to 1.5 inches, as
well as integrated water vapor transport per the ECWMF ensemble
percentiles giving values over 97% of climatology. NBM
exceedance probabilities of one inch of total rainfall for
Sunday through Sunday night range from 40 to 80% (east to west
through the outlook area), so around an inch of total rainfall
appears likely for portions of the forecast area.

Severe potential: SPC has a Marginal Risk (level 1 of 5) for
strong to severe storms up to almost I-80, and a Slight Risk
(level 2 of 5) is in place along and south of Highway 34. Even
an Enhanced (3 of 5) is not that far to the south of the
forecast area. These outlooks may be adjusted more so continue
to monitor the latest trends. The main threats as of now appear
to be damaging wind, large hail and a few tornadoes, with the
greatest threat farther to our south. CAM`s depict a broken line
of thunderstorms, possibly some severe, quickly moving
northeast across the forecast area between 6 pm and midnight
Sunday evening.

Monday through Friday: the pattern remains somewhat active
despite zonal flow aloft. Periodic shortwaves will translate
through the region, which could spark off some additional
showers and storms, but exact timing and location details remain
uncertain this far out. Temperatures are expected to gradually
warm up into the 70s for much of this time-frame.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 649 PM CDT Sat Apr 19 2025

VFR conditions are expected to continue through at least 12z
Sunday morning before an area of low pressure lifts from the
south, bringing widespread MVFR to IFR ceilings. Increasing
chances of showers and even some thunderstorms late in the day
will accompany this low pressure system, which could also result
in MVFR to IFR visibility reductions. Models are generally in
good agreement with the onset time of the initial showers Sunday
morning, but there remains some uncertainty on the exact timing
of a break in the shower activity by the afternoon, around 2-4
hours in duration, before the heaviest wave of showers and
storms moves in for Sunday evening.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

$$

SHORT TERM...Uttech
LONG TERM...Haase
AVIATION...Schultz