200
FXUS63 KDVN 012334
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
634 PM CDT Wed May 1 2024

.KEY MESSAGES...

- The upper level pattern is forecast to remain active with
  periodic chances of showers and storms through early next
  week.

- There is the risk for heavy rain and a Marginal risk for
  severe weather Thursday into Thursday evening.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 152 PM CDT Wed May 1 2024

High pressure sits across southeast South Dakota and northern
Iowa early this afternoon. There are some weak returns on radar
across the Middle Missouri Valley into central Iowa this
afternoon. Rain is being reported at Spencer Iowa as well as
Omaha with several sites reporting mid level cloudiness. Closer
to home, there are northwest winds with gusts of 20 to 25 mph.
Temperatures at 2 PM ranged from 63 degrees at Independence to
73 degrees at Moline.

Moisture and warm air advection is forecast to develop this
evening over central Iowa with the low level jet then veering
into eastern Iowa, northwest Illinois and far northeast
Missouri after 06 UTC. This would bring rain and potentially
embedded thunderstorms into the area after midnight but more
likely between 3 and 7 AM.

Several rounds of showers and storms are possible through the
day on Thursday as a weak surface low lifts a warm front across
the area. Depending on how the morning convection evolves,
there may be little in the way of CAPE across the area but
models do show a surge in instability behind the warm front.
There is 30 to 40 knots of 0 to 6 km shear which may be enough
for at least isolated severe storms late tomorrow afternoon
into the evening with a little bit of instability. The main
threat would be damaging winds. High temperatures will be
dependent on how long the rain is in the area but for now have
highs ranging from the upper 60s northwest of Cedar Rapids to
the lower 80s in west central Illinois.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 152 PM CDT Wed May 1 2024

A shortwave trough is forecast to lift northeastward and into
southern Canada to start the period. The NBM continues to
linger showers and storms across northwest Illinois counties on
Friday morning as the cold front exits the area. However, recent
model runs have continued to move the front and its associated
precipitation quickly out of the area on Friday. The remainder
of the day on Friday is forecast to be dry.

Southwesterly flow aloft will continue through the remainder of
the period until a deep trough moves across the CONUS late in
the period. This will allow several shortwave trough to lift
across the area through early next week and bring several
chances for showers and storms to the area about every 24 to 36
hours. These will be followed by periods of ridging and quiet
weather.

Temperatures are expected to be near to above normal through the
period. High temperatures the first week of may are in the lower
to mid 70s.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 634 PM CDT Wed May 1 2024

VFR conditions will eventually become MVFR as rain showers
overspread the area after 06z. There are some questions on when
this will start as there is a lot of llvl dry air, nonetheless,
rain will likely be falling near daybreak Thursday with chances
for storms. There could be a lull in the late morning before
more showers and storms affect the TAF sites. Have gone with
prob30s to handle thunder as timing and chances for thunder
overall are 20-40%.

&&

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

&&

$$

SHORT TERM...Cousins
LONG TERM...Cousins/McClure
AVIATION...Gibbs