872
FXUS63 KDVN 060851 CCA
AFDDVN

Area Forecast Discussion...CORRECTED
National Weather Service Quad Cities IA IL
351 AM CDT Sat Jul 6 2024

.KEY MESSAGES...

- Turning unsettled once again with periodic showers and storms
  tonight through at least Monday.

- Near normal temperatures through much of next week.

- Could Beryl have an impact on our weather next week? Time
  will tell.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 331 AM CDT Sat Jul 6 2024

Fairly tranquil conditions and seasonable temperatures are being
found early this morning and will persist throughout today, as
heights aloft undergo a bit of amplification between a Great
Lakes upper trough and an approaching shortwave diving into the
Northern Plains. Highs today should top out from near 80 to 85F
with a SCT-BKN cumulus deck. PoPs are not zero with building
instability and steepening lapse rates this afternoon, but the
lack of a coherent trigger and rather shallow moisture profiles
keep PoPs below mention.

Tonight, cyclonic vorticity advection ahead of the approaching
Northern Plains shortwave and moisture advection attendant to a
veering 30+ kt low level jet will lead to chances (40-60%) for
showers and storms by late evening and especially overnight,
mainly north and west of the Quad Cities. Severe weather is not
anticipated, but some gusty winds may be possible from a waning
cool pool off decaying remnants of more organized convection to
our west, as hinted at by some of the CAMs.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 331 AM CDT Sat Jul 6 2024

A quasi-omega block is forecast through early next week, with
a series of shortwaves traversing along the SW to NE
oriented mid/upper flow ahead of a mean upper trough over the
Upper Mississippi Valley. This will keep the pattern unsettled
owing to periodic showers and storms through at least Monday
and possibly into Tuesday. PoPs will be high at times (60+%),
but placement will vary pending the track of the shortwaves and
location of a wavering surface frontal boundary. Deep layer
shear looks generally marginal as typical for July and thus
any organized severe weather threat appears low at this time.
However, will have to keep an eye out for any augmentation of
the deep layer wind fields by any shortwaves, which could
foster a severe weather threat if juxtaposed with favorable
diurnal timing and sufficient instability. The threat for
widespread heavy or excessive rainfall also appears low at this
time, with 00z GEFS indicating probabilities of >1 inch of total
QPF through 12z Tuesday at 30-50% and ECE at just 20-30%. This
would be good news for area rivers. We are monitoring the track of
Tropical Storm Beryl, which is currently moving into the south
central Gulf of Mexico. According to the latest NHC forecast it is
expected to intensify into a Hurricane before reaching the lower
and middle Texas coast late Sunday and Monday, then weaken to a
Tropical Depression while reaching the Lower Mississippi Valley by
Wednesday evening. The GFS Vertically Integrated Water Vapor
Transport (IVT) plots does suggest the potential for at least some
connection of moisture from the remnants of Beryl poleward into
the existing moist conveyor ahead of the front in the region. That
being said, the strongest IVT does show to remain disconnected
and closer to remnant low center, but nonetheless this will be
worth monitoring for any potential for a deeper connection leading
to a more widespread heavy rain threat ahead of the frontal
boundary draped across the area. Otherwise, the general consensus
of the ensemble guidance beyond mid next week keeps the remnants
of Beryl well south/east of the area into the Ohio/Tennessee
Valleys. It is possible being on the northwest flank of this
system that subsidence could increase enough to give us several
days of dry weather from Wednesday through Friday and possibly
deeper into next weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1210 AM CDT Sat Jul 6 2024

VFR looks to be predominant through the TAF cycle, although periods of
MVFR ceilings and/or visibility is possible toward daybreak and
through Saturday morning mainly at KDBQ between valley fog and
some advective potential of stratus from southern Wisconsin.
Can`t also rule out a very brief MVFR ceiling at KMLI mid to late
morning before mixing promotes lifting of cumulus bases. Late in the
period we may see some convection approach eastern Iowa, but the
better potential exists primarily after 06z-12z Sunday for portions
of the area. Winds will remain light throughout generally favoring from
a W/NW direction today, then becoming southerly tonight.

&&

.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...McClure
LONG TERM...McClure
AVIATION...McClure
HYDROLOGY...Cousins