007
FXUS63 KDVN 171020
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
520 AM CDT Sat Aug 17 2024

.KEY MESSAGES...

- Cyclonic flow aloft, along with wrap around moisture, and a wave
of channeled vorticity will help bring another round of diurnally
driven showers and storms this afternoon/early evening.

- A remarkably quiet stretch of weather is forecast for Sunday
  through Friday, with seasonal temperatures.&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 208 AM CDT Sat Aug 17 2024

Today will be more directly impacted by the upper low pressure over
the Great Lakes than yesterday, or any day ahead. We will be
advecting in cloud cover from the north to start the day, which will
initially help keep the north cool through the morning, while
partial to mostly sunny skies are found over our south this morning.
By afternoon, enough heating is expected to combine with the weak
forcing, and PWATs over 1 inch to bring scattered showers and storms
to our northeast 2/3. Unlike yesterday, when we built enough CAPE
ahead of shower chances that they become strong, today we should see
less available CAPE, -weaker- but potentially a bit more
widespread area of convective development. QPF is forecast to be
very low, however, with PWATs over 1 inch, some heavy downpours
are certainly expected with any afternoon shower/storm. The
weak lift should move southeast/east of the area by 6-8pm, and
with some dry advection toward evening, we should see a quick
end to any shower/storms in that period.

Highs today, should eventually climb to the upper 70s north to the
lower 80s south, with some fluctuations back to the low 70s any time
a shower passes through.

Tonight, with cloud cover thinning out through the evening, lows in
the lower to mid 60s are expected.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 208 AM CDT Sat Aug 17 2024

Today will be more directly impacted by the upper low pressure over
the Great Lakes than yesterday, or any day ahead. We will be
advecting in cloud cover from the north to start the day, which will
initially help keep the north cool through the morning, while
partial to mostly sunny skies are found over our south this morning.
By afternoon, enough heating is expected to combine with the weak
forcing, and PWATs over 1 inch to bring scattered showers and storms
to our northeast 2/3. Unlike yesterday, when we built enough CAPE
ahead of shower chances that they become strong, today we should see
less available CAPE, -weaker- but potentially a bit more
widespread area of convective development. QPF is forecast to be
very low, however, with PWATs over 1 inch, some heavy downpours
are certainly expected with any afternoon shower/storm. The
weak lift should move southeast/east of the area by 6-8pm, and
with some dry advection toward evening, we should see a quick
end to any shower/storms in that period.

Highs today, should eventually climb to the upper 70s north to the
lower 80s south, with some fluctuations back to the low 70s any time
a shower passes through.

Tonight, with cloud cover thinning out through the evening, lows in
the lower to mid 60s are expected.


&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 208 AM CDT Sat Aug 17 2024

Sunday through Thursday, we will see an extended period of stable
seasonal weather, with highs in the upper 70s to lower 80s each day,
and lows in the mid 50s to low 60s each night.

Towards the end of the period, (Friday and beyond), there is very
good agreement in ensemble and deterministic models showing the
strong upper high pressure in the southern Plains shifting/expanding
northward.  This lends to high confidence on warm/hot weather
towards the end of the week.  Just in time for schools to start!

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 519 AM CDT Sat Aug 17 2024

An upper low over the Great Lakes will send moisture
southeastward from Minnesota into our area early this morning,
lingering through Noon, before cigs will rise to VFR during the
afternoon hours Saturday. This will be a period of 700 to 1800
ft cigs, with the lowest found in northeast Iowa, near DBQ
through 17z. The afternoon will feature lifting cigs, but also a
few small showers/storms moving through. These are expected to
move over northeast Iowa and northwest Illinois during the 18Z
to 00Z time frame, followed by clearing and VFR dry conditions
into Saturday night.
&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin
AVIATION...Ervin