900
FXUS63 KDVN 040525
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1225 AM CDT Sat May 4 2024

.KEY MESSAGES...

- Upper level pattern remains active, with periodic chances for
  showers and storms through next week.

- The Storm Prediction Center has a Marginal Risk (level 1 of 5)
  for severe storms on Saturday for portions of the area.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 145 PM CDT Fri May 3 2024

This Evening and Tonight: High pressure will remain in control
leading to light winds and mainly clear skies with lows in the
40s to low/mid 50s far southwest.

Saturday: A cold front is forecast to track across eastern Iowa
and northwest Illinois during the morning and afternoon. A
stronger line of showers and storms moving through western into
central Iowa tonight (Friday night) is expected to gradually
weaken into Saturday morning as it pushes into a more stable
air mass across our western outlook area (with surface
dewpoints only in the 40s early in the day). However, some rain
is likely as this first wave moves through and have 50-70%
chances west of the Mississippi River for the morning hours.
Low-level theta-e advection coupled with diurnal heating will
allow for the build up of SBCAPE into Saturday afternoon for
locations along and east of the Mississippi River. This will
coincide with the passage of the cold front and could result in
redevelopment of scattered showers and storms between 2 PM to
7 PM, right now favored for eastern counties. Per HREF surface-
based CAPE near 1000 J/kg and deep layer shear around 30 kts,
the environment may be supportive of a few strong to severe
storms which is in line with SPC`s Marginal Risk (level 1 of 5).
The primary threats are hail and gusty winds.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 145 PM CDT Fri May 3 2024

Another chilly night is expected Saturday night, with lows in
the 40s to lower 50s, but Sunday, much like today, appears to be
seasonally pleasant in the lower 70s.

Global models are in good agreement that a large upper trof will
build into the Midwest in the Monday through Wednesday time frame.
This should sweep another dynamically supported warm advection band
of showers and storms through our area centered on Monday night
into Tuesday. The quick flow aloft, and progressive boundary
should keep QPF totals from being problematic, with most spots
well under 1 inch in the NBM/WPC mean.

There is potential for storms to redevelop Tuesday afternoon,
but confidence is low on this scenario. SPC has outlooked the
area for a slight severe risk, but again confidence regarding
the details is low as it will depend on timing and placement of
a cold front moving through the Midwest. Stay tuned.

Seasonally pleasant temperatures are forecast through Wednesday,
with a bit of a cool down by late week, as the upper trof deepens
over the Midwest.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1221 AM CDT Sat May 4 2024

A locally quiet and clear night of VFR weather will see an
approaching area of showers and thunderstorms moving east
through western Iowa tonight. These will be in a dissipating
stage as they enter eastern Iowa this morning, which is now
included as a temporary condition at CID and DBQ. Increasing
south winds will bring moisture into the area, but looking
upstream, MVFR cigs are not found outside of rainfall, as
dewpoints remain low until the convergence of the front arrive.
Thus, I`ve cut back on the MVFR cigs through the day, and
focused more on the two periods of rain/thunder potential, one
in the morning west, and the other in the mid to late afternoon
along and east of the Mississippi River. Some of the afternoon
storms could offer a strong wind gust, and brief IFR conditions.



&&

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

&&

$$

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