647
FXUS63 KDVN 031713
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1213 PM CDT Wed Jul 3 2024

...Late Morning Hydrology Update...


.KEY MESSAGES...

- Showers and storms are possible on Independence Day as a warm
  front lifts north through the area followed by a cold front.
  There is a Marginal Risk for severe weather for the western
  third of the CWA.

- Active pattern remains through the long term, with near daily
  chances for precipitation somewhere in our forecast area.
  Saturday may be the best chance at a dry day, with slight-
  chance PoPs daily from there.

- Moderate to Major River Flooding continues, with further
  changes to river forecasts expected as we transition from
  predicted rainfall to observed rainfall over the next 36 hrs.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 249 AM CDT Wed Jul 3 2024

As the cold front that brought the severe weather yesterday slowly
moves out, we may continue to see remnant showers and storms,
especially in our southeast this morning. Much of this activity
should be out of the area by 7am-10am.

Weak high pressure will move through the area today, which should
allow for a brief break in the weather. Much of the day should
remain dry, as dry advection works into the area behind yesterdays
system. A weak upper wave will pass through the area today, but we
are not expecting much precipitation from this, due to lacking
moisture. The best chance will be late tonight, where we introduce
slight-chance PoPs to the area, mainly focusing in the south. This
is the area in which the best forcing and moisture will be found,
but confidence remains low on overall coverage of shower activity.
Plus, much of this will be seen well after dark, so you may not even
notice it rained. Any area that receives rain tonight will be
overall low on the accumulation-side. Rather, enough to wet the
pavement for most, with maybe upwards to a quarter of an inch
for some. If we manage to get some embedded thunderstorms, we
may see some higher amounts up to a half inch. Although,
confidence in that is quite low.

Thus, enjoy this brief period of calm weather, as an active
pattern continues throughout the midwest. Temperatures today
will be in the mid-80s, thanks to some sun, cooling off into the
60s once again tonight. There will be a nice mix of clouds/sun
through the day today, with more cloud cover moving in this
evening and tonight.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 249 AM CDT Wed Jul 3 2024

July 4th...Unfortunately, it looks like we will have the potential
to see more showers and storms on Thursday, July 4th. Wave digs
south towards the area through the day, with a weak leading wave
passing through during the morning. The wave moving through that
morning is the remnant wave from the prior night, which may bring
light precipitation to the area. This will fade out through the day,
leaving the focus on the deeper wave pushing towards us. Moisture
return is relatively weak through much of the day, limiting the
coverage until later in the day, when the deeper wave brings a bit
more moisture into the area. Temperatures will be in the mid 80s
through the day, with surface dew points increasing into the mid-
upper 60s, yields upwards to 1000-2000 J/Kg CAPE. This will couple
with 40-50+ KTs of shear, resulting in the potential for some
strong to severe storms. Cold front is expected to come through
that evening, which will be the focus for the strong storms.
Thus, we should get through much of the day without much of a
severe chance. Currently, the SPC highlights our area in a
Marginal Risk (level 1/5) for severe weather. The overall
confidence in the severe threat is low, as it will be
conditional on how much instability we build through the day.
So, the more sun that we get, the more instability we can build.
Although, if we are left with clouds and showers/storms through
much of the day, that will limit destabilization, along with
the severe threat. Will watch this closely, but be prepared for
the potential of a damp cookout!

Friday...Longer range projections suggest upper low complex to
meander eastward acrs WI, with cool pool aloft effects making for
isolated to wdly sctrd instability showers possible acrs the area,
especially north of I-80. Ambient cumulus, a few showers and the
cool pool itself may keep temps in the 70s to around 80, so a below
normal day for July.

Saturday and Sunday...Medium range ensemble patterns hint at rather
broad upper troffiness establishing or more accurately getting re-
established acrs much of the upper midwest by another digging
northern stream upper wave into the upper MS RVR Valley. Hopefully
most of Saturday will be dry ahead of this incoming process with
moderating temps back into the 80s. There may be a few showers and
storms in the north Sat night, but as the upper trof axis slides
overhead, Sunday afternoon and evening may be a better chance for
isolated to sctrd showers and storms to occur. Seasonable temps in
the low to mid 80s Sunday.

Early next week...Upper jet and synoptic scale feature progs suggest
the longer wave upper trof to linger and even deepen acrs much of
the mid to upper MS RVR Valley this period. This would allow for
wdly sctrd shower and storm development in the afternoon heating
under this feature. The unorganized buoyancy pop up type precip
warrants only low CHC POPs at this juncture in time. Near seasonable
to somewhat below normal temps this period.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 527 AM CDT Wed Jul 3 2024

Low stratus and patchy fog continue to pass through the area
this morning, dropping cigs to 300-600 ft and vis down to 1-3 SM
at times. These conditions have been covered by TEMPOs at all
terminals. By 15z, much of these conditions should improve.
Thus, VFR conditions will prevail beyond then, with clouds
continuing to scatter out and lift by 18z. Winds will remain out
of the west-northwest, generally between 5-10 KTs. After 00z
this evening, winds will go light and variable, as high pressure
passes overhead.

&&

.HYDROLOGY...
Issued at 1211 PM CDT Wed Jul 3 2024

The forecasts along the Mississippi River havn`t changed much from
the previous ones, with many forecast points cresting into the
weekend. Locations from Dubuque to Keokuk are still expected to
crest over their respective Major Flood Stage levels. At Gregory
Landing, a crest in the Moderate category is forecast. The crest is
forecast near Dubuque and Bellevue on July 4th and 5th, with sites
from Fulton to Keokuk seeing a crest between July 6th and 8th.

On the Maquoketa at Manchester, the heavy rains and training
thunderstorms to produce them did not materialize and shifted to the
south of that basin. Thus it is no longer expected to reach the
minor flood stage and the warning has been cancelled.

Also with the rainfall amounts not being quite as high or widespread
as earlier anticipated in some of the more northern basins, several
tributary forecasts have been toned down some. Ongoing river flood
watches and warnings on the Cedar, Iowa, Wapsi, Skunk, and Maquoketa
Rivers have been adjusted accordingly to the rainfall reports from
this morning. But with a few other areas indeed receiving torrential
rainfall a bit further south, the river flood watches for the North
Skunk River near Sigourney and English River at Kalona have been
upgraded to river flood warnings.

Current projections for additional rainfall over the next few days
through the end of the week look more spotty with widespread heavy
rain not likely. This should help maintain the current forecasts
from deviating too much from the most recent forecasts.

&&

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

&&

$$

SHORT TERM...Gunkel
LONG TERM...Gunkel/12
AVIATION...Gunkel
HYDROLOGY...12