045
FXUS63 KDVN 101041
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
541 AM CDT Fri May 10 2024

.KEY MESSAGES...

- Patchy dense fog is possible early this morning north and west
  of the Quad Cities.

- Gusty winds are possible in scattered showers and isolated
  thunderstorms late this evening and tonight (Friday night).

- Warm weather is expected on Sunday with highs near 80 F!

- The wet pattern will continue with occasional chances for
  showers and storms from Sunday into Tuesday AM. There may be a
  break in the rain later Tuesday through Wednesday before the
  next system arrives late next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 300 AM CDT Fri May 10 2024

Early This Morning: GOES nighttime microphysics imagery showed
an area of low clouds covering most of eastern Iowa and
northwest Illinois, coincident with a sharp SW to NE oriented
500mb trough axis across the local area. Radar trends continue
to show isolated (less than 20% coverage) shower activity in the
outlook area, slowly drifting from north to south. Much of the
area will stay dry into early this morning, but a few locations
could receive a brief period of light to moderate rain. Light
winds and low dewpoint depressions may result in areas of
shallow fog where skies clear out.

Mid Morning through Afternoon: A shortwave trough extending
from the western Great Lakes into Illinois and Iowa will shift
into the Ohio Valley by early to mid morning, taking any
lingering isolated showers with it. Seasonable temps are
expected today with afternoon highs near 70F.

This Evening and Tonight: Another shortwave trough and
associated cold front will drop in from the NW, kicking off
scattered showers and possibly a few thunderstorms mainly
between 7 PM - midnight. A few of the showers/storms could
produce gusty winds over 40 mph. The late timing of the front
should limit the wind gust potential and models are showing
minimal MLCAPE (few hundred J/kg) across the outlook area by
tonight. Skies will quickly clear from NW to SE between about
10 PM - 1 AM, giving us a chance to see the Northern Lights
(Aurora)!

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 300 AM CDT Fri May 10 2024

Saturday: A nice day is expected with breezy NW winds and highs
near 70 F.

Sunday: Low pressure passing across Minnesota and Wisconsin
will pull warm and more moist air northward into the local area
with forecast highs in the upper 70s to lower 80s. However,
surface dewpoints holding in the 50s will limit instability to
near 1000 J/kg (MLCAPE) or less during the afternoon/evening,
and deep layer shear looks low too. For these reason, do not
anticipate severe weather but scattered showers and storms could
develop during peak heating and last into Sunday night.

Monday: A cut-off upper low is forecast to track from the Four
Corners region through the Lower to Mid Mississippi Valley
early in the week. Model consensus keeps the local area on the
cool northern side of this system, which would limit the severe
potential and could lead to colder highs than currently
forecast. The latest NBM has max temps close to 70 F and the
highest rain chances south of I-80 (60-80%).

Tuesday On: There is uncertainty on how fast the rain moves out
with most of the models lingering it across the south through
Tuesday morning. Generally, we`ll be looking at a more tranquil
pattern later Tuesday into Wednesday as a backdoor cold front
advects in a cooler and drier air mass from the NE. NBM highs
may be too warm for Wednesday, and latest trends in the
deterministic models is to delay the next round of showers and
storms until Wednesday night into Thursday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 531 AM CDT Fri May 10 2024

Shallow fog is possible mainly at CID and DBQ early this
morning, leading to brief IFR/LIFR conditions. Otherwise,
periods of MVFR ceilings will persist at all the terminals
through the mid morning before improving to VFR. Scattered
showers and isolated storms are possible late this evening into
tonight along and ahead of a cold front. Gusty winds could
accompany the showers and storms, but no severe weather is
expected.

&&

.HYDROLOGY...
Issued at 846 PM CDT Thu May 9 2024

Changes...

The flood watch for the Wapsipinicon River near De Witt
has been changed to a flood warning.

Discussion:Active period again with periodic rounds of showers
and thunderstorms as another deep trough comes out of the
Rockies and into the middle of the country. However, way too
early to determine severe threats or rainfall amounts. Highs
will be well into the 70s to around 80.

The Cedar, Iowa and Wapsipinicon Rivers continue to rise as a
result of the rainfall over the past 30 hours. The forecast for
De Witt has not changed much over the past 24 hours, thus
confidence has increased that it will reach flood stage within
the next 24 hours.

The overall situation with the Cedar and Iowa Rivers is more
uncertain. While there is a better accounting of the overall
runoff compared to 24 hours ago, the forecast for Marengo on the
Iowa river is just barely above flood stage. Since the flood
crest will gradually attenuate due to gravity as it moves
downstream, there is a 30 to 40 percent chance that the crest at
Marengo may occur just below flood stage.

On the Cedar River near Conesville the flood crest will also
attenuate as it moves downstream. However, the crest is further
above flood stage which means there is a 50 percent chance of
reaching flood stage.

Rainfall over the next 72 hours and where it occurs will be the
deciding factor as to whether or not the Cedar and Iowa Rivers
will reach flood stage near Conesville and at Marengo
respectively. If the rainfall is lighter than expected then
river forecasts may be lowered. However, if rainfall is heavier
than expected then river forecasts may be raised.

&&

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

&&

$$

SHORT TERM...Uttech
LONG TERM...Uttech
AVIATION...Uttech
HYDROLOGY...8