491
FXUS63 KDVN 170545
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1245 AM CDT Wed Jul 17 2024

.KEY MESSAGES...

- Cooler and drier air will continue to spread across the area
  through mid week.

- Dry pleasant weather will continue into the first half of the
  weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 223 PM CDT Tue Jul 16 2024

We are looking at a dry period of weather tonight through
Wednesday night as lower dew point air works south across the
area due to high pressure building over the northern Plains and
Upper Midwest. Lows will be down into the 60s tonight, with
cooler 50s Wednesday night. Highs Wednesday 75 to 80 with dew
points about 10 degrees lower than today.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 223 PM CDT Tue Jul 16 2024

The aforementioned high pressure system will continue southeast
through the end of the work week, with temperatures a bit below
average and dry weather continuing. The overall pattern will be
one where a strong upper level ridge will be set up over the
Four Corners region, with a persistent upper trof over the
eastern CONUS. The dry weather should continue into Saturday.
The forecast will be low confidence one for next Sunday and
Monday. There are some model members suggesting a limited chance
of precipitation Sunday into Monday. Confidence is very low at
this time given the overall high amplitude pattern, and low
confidence in the models ability to resolve smaller scale
features that might drive precip chances.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1236 AM CDT Wed Jul 17 2024

Latest surface analysis has the cold front well south of the
area. Latest 0506Z IR satellite has a few mid level clouds
across parts of southern Iowa and a pocket of broken mid-level
clouds across north central Iowa. Expect the pocket of mid-level
broken clouds to move southeast and impact TAF sites for a few
hours. Otherwise, expect VFR conditions to prevail through the
TAF period. Winds will be light northwest-north and become 10 to
15 KTs during several hours during the TAF period. No
significant weather is expected at this time.

&&

.HYDROLOGY...
Issued at 939 PM CDT Tue Jul 16 2024

Swaths of heavy rain and resultant run-off produced by severe
thunderstorms Monday and Monday night across the area are
aggravating ongoing river flooding or producing new flooding
situations.

The Mississippi River has crested at all sites now, but several will
experience stalled falls or steady trends over the next several days
due to recent bouts of heavy rain, local run-off, and tributary
input. L&D 19 at Keokuk and Gregory Landing will even experience
secondary rises into the weekend.

Tributary Rivers:

Very heavy rainfall on the upper reaches of the Rock River basin
over the past several days, as well as some localized run-off may
produce Major Flooding near Joslin and at Moline by Friday. The
river flood warnings for this have been posted, but there is some
uncertainty that they will actually get that high and Moderate
flooding may be more in line for these sites. The Rock at Como will
be in Minor flood through Saturday evening.

The Pecatonica River basin also received heavy rain, and the site
at Freeport IL is expected to rise well into Minor flood by Friday.

The lower Wapsipinicon River near Dewitt, IA is experiencing
localized run-off from the heavy rainfall last night of 1-2 inches.
It is actually jumping back above flood stage due to this process
and a new warning for that site has been issued this morning. Water
levels are expected to fluctuate around the flood stage through
Thursday night before falling off and maintaining the fall.

Backwater effects from the Mississippi River will keep the lower
Iowa River just below flood stage for the remainder of the week.

Further south, torrential rainfall and run-off from last night may
produce a large rise to action stage on the La Moine River near
Colmar in west central IL. But the extent and speed is still
somewhat uncertain and will have to watch river rise trends through
Thursday.

&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin
AVIATION...Gunkel/Holicky
HYDROLOGY...Gunkel