738
FXUS63 KDVN 141640
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1140 AM CDT Sun Jul 14 2024

.KEY MESSAGES...

- Scattered to numerous storms prior to 9 AM; some gusty but
  expected to be sub-severe

- The heat continues for today and Monday with peak heat
  indices between 100 to 110 F...slightly offset by winds of 10
  to 20 mph.

- Strong scattered thunderstorms are possible this evening and
  overnight again, with low confidence on them occurring.
  Another organized round of heavy rain and severe weather is
  forecast Monday PM into Tuesday as a strong cold front
  arrives.

- Moderate to major river flooding continues on the Mississippi
  River with most sites crested or cresting in the coming days.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 204 AM CDT Sun Jul 14 2024

Our local area was brushed by strong convection late in the evening,
affecting Stephenson co with heavy rain and gusty winds, while areas
just east were greatly impacted by torrential rains.  This ring of
fire zone just to the northeast is forecast to be active again
today, but could be a bit farther northeast than the past 24 hours.

At the start of today, area wide, some very high based showers
and storms could be ongoing on top of the LLJ position aimed
into Wisconsin. This could bring some scattered activity for a
few hours, with limited impacts to brief downpours. Otherwise,
we`re closely watching the convective cluster moving through the
Twin Cities this morning, as that could again brush the
northeastern counties with stronger thunderstorms.

Otherwise today will be hot and breezy!  Like yesterday, a moist air
mass, combined with peak crop evapotranspiration will help dew
points rise to the 72 to 77 range, and with temperatures in the 90
to 94 range, heat indices will reach 100 to 105 in many areas.
A heat advisory will be issued for all counties, from 1 PM to 8
PM.

Tonight, a low chance exists that strong to severe storms can again
brush our northeast is there, but most models continue to keep the
action well northeast of our CWA. CAPE over 4000 will ensure any
activity will be strong of it happens.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 204 AM CDT Sun Jul 14 2024

The hot weather will continue on Monday with chances for scattered
showers and storms as a cold front gradually drops in from the
north. Models continue to show a strong EML, but the frontal
position could serve to erode that with time, especially after dark.
The ample CAPE over 4000 J/KG would support strong storms, as would
the increasing shear from the westerly flow aloft. For now, pops are
in the 40-60% range by Monday night into Tuesday morning.

The main threat for Monday night`s storms will be damaging winds,
but another threat is heavy rainfall over 2 inches. We`ll advertise
some heavy rain threat through the night Monday night, as the front
timing has slowed, with less northwest flow establishing itself
until later Tuesday.

Tuesday night through the weekend ahead continue to appear cooler
than normal, and extremely pleasant. Overnight lows well into the
50s are forecast on several nights, giving our air conditioning a
bit of a break.

ERVIN

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 630 AM CDT Sun Jul 14 2024

Through 14Z, storms will at least be near the TAF sites, and
likely passing over MLI and BRL. The storms over far eastern
Iowa and northwest Illinois are gusty and 30+ kt gusts are
probable with these as long as they persist in a semi-organized
fashion. This episode of storms should be weakened/out of the
area by 14-15Z. The disrupted surface winds will turn around
southwesterly and be gusty at times this afternoon.

Confidence is starting to nudge upwards that there will be mid-
afternoon through early evening storms in the region, renewing
on the lingering disturbance from storms in far western Iowa
early this morning. If indeed storms do regenerate this
afternoon, they will have the potentail to be scattered severe.
The weather pattern favors a domino-like effect where current
rounds of storms influence later rounds, and so its tough to say
if later tonight will have additoinal storms.

Apart from storms and any immediate aftermath, conditions will
otherwise be VFR through the TAF.

&&

.HYDROLOGY...
Issued at 1126 AM CDT Sun Jul 14 2024

A broad crest on the Mississippi River is occurring from
Gladstone, IL (L/D 18) down through Gregory Landing, MO. This
crest will last up to two days. Upstream of Keithsburg, IL
river levels are falling.

Tributary Rivers:

The Cedar River near Conesville, IA fell below flood stage last
evening and will continue falling over the next week.

The lower Wapsipinicon River near Dewitt, IA is expected to fall
below flood stage around sunrise Monday morning. The rate of
fall on the river has slowed down due to locally heavy rainfall
overnight.

Backwater effects from the Mississippi River continue to lessen
on the lower Iowa River. The Iowa River at Oakville, IA is
forecast to drop just below flood stage this evening but then
remain near flood stage through the remainder of this week.

Very heavy rainfall occurred late Saturday afternoon and night
over the middle and upper parts of the Rock River basin. Ground
truth reports indicate a large swath of 2 to 5 inches of rain
occurred in the basin. Thus the Rock River will begin rising
with river levels approaching flood stage. There is a 50
percent probability that portions of the lower Rock River could
rise above flood stage in the next 24 to 48 hours.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Heat Advisory until 9 PM CDT this evening for IAZ040>042-
     051>054-063>068-076>078-087>089-098-099.
IL...Heat Advisory until 9 PM CDT this evening for ILZ001-002-007-
     009-015>018-024>026-034-035.
MO...Heat Advisory until 9 PM CDT this evening for MOZ009-010.

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin
AVIATION...Friedlein
HYDROLOGY...08