680
FXUS63 KDVN 161741
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1241 PM CDT Thu May 16 2024

.KEY MESSAGES...

- Scattered showers and a few storms late tonight and Thursday.

- Highs warming into the 80s for several days ahead.

- Depending on where a developing storm track lays out, it could
  be a potentially wet pattern across the region next week with
  several rounds of heavy rain possible.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 250 PM CDT Wed May 15 2024

Weak area of high pressure was centered across eastern Missouri
early this morning, with a cold front just off to our west
across northwest Iowa and southeast Nebraska. This front was
just ahead of a weak shortwave, which per water vapor imagery
was over eastern South Dakota. Scattered showers and storms were
noted ahead of the shortwave and front per KDMX/KMPX, but had
showed a decreasing intensity trend as they were moving east
into more stable air across our CWA.

Heading through today, we will begin to see shower and storm
coverage increase as the front and shortwave move across the area.
Look for more scattered activity during the morning hours to become
more pronounced mainly along and east of the Mississippi during
the afternoon with increasing instability and moisture
interacting with the wave. SBCAPE, depending on degree of warmth
with clouds in place, should get up to around 1000-1500 J/kg by
early afternoon with increasing deep layer shear around 30-35
kts. This is especially favored across northwest Illinois where
there is some potential for storms to become strong. SPC
maintains a Level 1 (marginal) risk for severe weather in this
area, with the risk mainly focused across southwest Wisconsin
nearer to better surface convergence. The primary threats would
be large hail and damaging winds. Elsewhere, showers and storms
could produce some heavy rain as PWATs ahead of the front climb
to around 1.00-1.20".

Tonight, another round of weak high pressure will bring quiet
weather to the area. Weak CAA and low-level flow with keep temps
from falling too much, with lows in the mid to upper 50s
expected.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 250 PM CDT Wed May 15 2024

Friday through Saturday...

A stretch of quiet weather is expected during this period as mid-
level ridging builds over the Midwest and Great Lakes. Though some
deterministic guidance paints a weak shortwave moving overhead
Friday into Saturday, they have backed off on POPs with weaker
overall forcing and moisture. Therefore, we should remain dry
with warm temps. Look for highs each day in the 80s, with
overnight lows in the 50s/60s.

Saturday Night on...

Ridging will shift southeast of the area and open the door for a
shortwave train to set up across portions of the Midwest and upper
Midwest. Guidance places us either pretty close to the track or
within the track itself, which would increase potential for clusters
of showers & storms/MCSs to impact the area at times beginning early
next week. There remains quite a bit of uncertainty in storm tracks,
severity and timing at this time, as models do not handle these
features well several days out. Regardless, will run with the
NBM which has all of eastern Iowa, northwest Illinois and
northeast Missouri in at least a chance (20-50%) of
precipitation Sunday on. Please continue to monitor the latest
forecast information, especially over the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1227 PM CDT Thu May 16 2024

A cool front has shifted to the east of KCID early this
afternoon and will move through the remainder of the TAF sites
by 00 UTC on Thursday. Ahead of the front, scattered showers and
storms are possible at KDBQ, KMLI, and KBRL with lower
confidence that a thunderstorms will directly impact any TAF
site and added a tempo group for showers at each of the sites.
MVFR visibilities and ceilings are possible in the strongest
showers. Winds will switch from southwest to west with the
passage of the cold front before becoming light and variable.

&&

.HYDROLOGY...
Issued at 1051 AM CDT Thu May 16 2024

Changes: None.
Discussion...

Most tributary rivers in eastern Iowa have crested and are
slowly dropping. The exception is the lower Iowa River where the
crest is currently working its way through Wapello and Oakville.

On the Mississippi, Gladstone and Burlington will begin a broad
crest just above flood stage that will continue through Friday.

After a relatively dry weekend, the active weather pattern will
return next week with the potential for several rounds of rain.
While rainfall amounts continue to be somewhat uncertain, any
heavy rainfall would prolong the high river levels on tributary
rivers in eastern Iowa, northern Illinois and on the Mississippi
River.

The longer range outlook through the end of the month has a
40-42 percent probability of above normal rainfall. This outlook
suggests the potential for additional improvement with the
severe drought conditions across eastern Iowa. Unfortunately,
this outlook would also suggest that river levels could remain
higher than normal.

&&

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

&&

$$

SHORT TERM...Speck
LONG TERM...Speck
AVIATION...Cousins
HYDROLOGY...08