183
FXUS63 KDVN 051931
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
231 PM CDT Fri Jul 5 2024

.KEY MESSAGES...

- Isolated to scattered showers ending this evening. A brief
  funnel cloud may occur in any strong updraft of a developing
  shower or thunderstorm.

- Moderate to major river flooding continues.

- Periodic rain chances late this weekend and into early next
  week with temperatures slightly below normal.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 228 PM CDT Fri Jul 5 2024

The upper level disturbance producing the showers and possibly a
couple of rogue thunderstorms will move into the Great Lakes
tonight. The loss of forcing means that the showers will quickly
dissipate with sunset leaving a dry overnight for the area.

While not certain, brief funnel clouds could occur late this
afternoon in any strong updraft of a developing convective cell.

Saturday will be dry with temperatures slightly below normal as high
pressure quickly moves through the Midwest.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 228 PM CDT Fri Jul 5 2024

Saturday night through Tuesday
Assessment...medium confidence

Return flow develops Saturday night but moisture is initially
lagging. The moisture associated with the upper level disturbance
should be enough to generate isolated to scattered showers late
Saturday night into Sunday along with a few thunderstorms. Coverage
looks to be in the 30-40 percent range so some areas will probably
remain dry.

A secondary upper level disturbance arrives Sunday night into
Monday. Interestingly a couple of the global models are attempting
to connect the moisture from this disturbance with the tropical
moisture of Beryl. If this scenario occurs, then the Sunday night
into Monday time frame would hold the better chance of rain (50-60
percent) for the area.

Monday night into Tuesday is more in question regarding the rain
chances. From the large scale picture the better moisture is shunted
off to the east which would indicate little if any rain occurring as
an upper low drops into the Midwest. However, there are several
ensemble members from the various global models generating
precipitation for the area.

The model consensus does carry a risk of rain (generally 20-35
percent) for Monday night and Tuesday. However, unless there is
additional moisture for the upper low to work with, the overall
areal coverage of any rain could be much lower. Thus the message is
that while there is a risk of rain Monday night into Tuesday, the
probability of dry conditions for much of the area is much higher.

Tuesday night through Friday
Assessment...medium to high confidence

The model consensus has mainly dry conditions through the period
with the exception of Wednesday.

On Wednesday another upper level disturbance will move through the
area. If sufficient moisture is available, the overall forcing will
induce diurnal showers and thunderstorms. There are some ensemble
members suggesting dry conditions on Wednesday but a majority
indicate some rain is possible. The overall coverage will be on the
light side (20-30 percent) so much of the area may remain dry.

The wildcard in all this is the remnants of Beryl and its associated
tropical moisture feed.  Right now the global models are indicating
that the tropical moisture will pass well south of the area.
&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1232 PM CDT Fri Jul 5 2024

An upper level disturbance rotating through eastern Iowa and
northern Illinois will bring isolated to scattered SHRA through
00z/06. A rogue TSRA cannot be ruled out but the probability of
that occurring is 10 percent and thus was not included in the
18z TAFs. Outside of the SHRA VFR conditions can be expected.
After 01z/06 VFR conditions will be seen as high pressure builds
into the Midwest.

&&

.HYDROLOGY...
Issued at 1141 AM CDT Fri Jul 5 2024

The forecast crests along the Mississippi River have been
delayed and are now showing a longer duration crest at several
locations due to some rainfall and forecast rainfall upstream.
Most of the crest values have been steady or only minor changes
in timing. Major flooding is forecast along most of the
Mississippi River. Mississippi River with long duration crests
occurring after July 7th. Keokuk is expected to get to the Major
Flood stage near the 7th or 8th, and Gregory Landing is
expected to crest in its Moderate flood category.

Tributary Rivers:

Over the next 7 days, Moderate flooding will continue on the
Wapsipinicon River at Dewitt and minor flooding will continue
at Conesville on the Cedar River. A flood watch remains in
effect for the Cedar River at Cedar Rapids due to rises from
routed flow and forecast rainfall.

Wapello on the Iowa River is expected to drop below minor flood
stage this afternoon. At Oakville, backwater from the
Mississippi will keep the level high, in minor flooding, through
July 11.

Within banks rises are occurring on the English River at Kalona
and on the North Skunk River at Sigourney.

Over the next seven days widespread heavy rain is not expected.

&&

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

&&

$$

SHORT TERM...08
LONG TERM...08
AVIATION...08
HYDROLOGY...Cousins