201
FXUS63 KDVN 120536
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1236 AM CDT Sun May 12 2024

.KEY MESSAGES...

- Quiet weather through Sunday morning. Clear skies expected
  tonight.

- Sunday will be the warmest day of the next seven with highs in
  the lower 80s. Isolated to scattered storms are possible late
  Sunday afternoon into Sunday night.

- Zonal flow across the CONUS will result in active weather
  continuing through the next week.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 206 PM CDT Sat May 11 2024

Confluent flow aloft over Upper Midwest this afternoon as 500 MB
ridging builds into the area at the surface and aloft. Visible
satellite imagery is showing some areas of diurnally driven
cumulus developing across Illinois and parts of Iowa. The KDVN
sounding showed a convective temperature of 69 degrees.
Temperatures at 2 PM ranged from 69 degrees at Freeport and
Dubuque to 76 degrees at Macomb. Northwest winds have been
gusting up to 35 MPH at times this afternoon but in general
winds are gusting up to 25 MPH.

High pressure will move southeastward across the area at the
surface and aloft through Sunday morning. This will bring quiet
weather to the area overnight The HRRR and HREF have been
showing some thinning high clouds moving across the area this
evening but do not expect widespread cloud overnight with dry
air in place. Winds will diminish tonight and become light and
variable. Low temperatures will generally be around 50 north of
a Independence to Clinton to Princeton Illinois line with lower
to mid 50s south.

On Sunday, the ridge axis will push to the southeast during the
morning as one shortwave dives into Michigan. The ECWMF is the
faster and farther south of the different solutions with the
cool front approaching the area by 00 UTC Sunday. CAMs do have
isolated to scattered showers and storms developing across the
area from 20 UTC (3 PM) along the Highway 20 corridor. Model
soundings show that brief gusty winds will be the main threat
but moisture is very limited and soundings are showing
inverted-V or onion sounding characteristics. Temperatures on
Sunday will be in the lower 80s. Forecast soundings show the
potential for gusty winds once again with a few gusts especially
across northwest Illinois and far eastern Iowa near 25 MPH.

Models have slowed precipitation moving into the area on Sunday
in association with a closed upper level low moving from
Colorado into eastern Kansas by 12 UTC Monday. The better
chances of 30 to 40 percent will remain west of the Mississippi
River overnight. Rainfall amounts will be light and range from
one to two tenths.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 206 PM CDT Sat May 11 2024

The 500 MB flow will remain zonal through the upcoming week
with an active northern (polar) and southern (sub tropical)
branches of the jet streams across the continental US. This will
result in several more chances for showers and storms. High
temperatures will be in the lower to mid 70s through mid week
before a warming trend beings into next weekend.

Monday: An upper low on the northern periphery of the
subtropical jet is forecast to slowly track from the Southern
Rockies to the Lower to Mid Mississippi Valley early in the
week. This will keep the local area on the cooler and more
stable side of the surface low. Rain is likely to spread in
from SW to NE during the morning and afternoon. NBM chances for
measurable rain range from near 50% in the far NW corner of the
outlook area to ~90% south of I-80. The 24 hour probability for
0.50" or more of rain reaches 50-70% south of I-80 and drops
down to 20% near Highway 20. The NBM may still be running too
warm for max temps due to the likelihood for widespread clouds
and rain; these may need to be lowered by several degrees in
later updates.

Tuesday - Friday: There remains uncertainty with how fast the
rain moves out on Tuesday. The ECMWF lingers the rain through
the morning across the south half of the outlook area, while
the GFS/CMC shift it to the SE more quickly. Our current
forecast is leaning towards the latter scenario. Then it looks
like we will get a break from the rain later Tuesday through
Wednesday before the next shortwave trough and associated cold
front arrive by Wednesday night into Thursday. Late week temps
are forecast to be slightly above normal in the low/mid 70s.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1231 AM CDT Sun May 12 2024

VFR continues into Sunday with SW winds increasing by mid/late
morning. There is a chance for scattered showers and isolated
thunderstorms Sunday evening into Sunday night. Have low
confidence on coverage, so for now only mentioned showers in a
PROB30 at CID.

&&

.HYDROLOGY...
Issued at 833 PM CDT Sat May 11 2024

Latest forecast this evening for the Wapsipinicon River near De
Witt has a slower rise by several tenths of a foot. However,
minor flooding is still expected but a little later now on
Tuesday May 14th. Given how the initial crest was lower and
attenuation of routed flow confidence is dropping, confidence is
low in just how high above flood stage the river will get. Will
continue the Flood Warning with this issuance.

In addition, the forecasts on the Cedar and Iowa Rivers have
lowered at Conesville and Marengo. Both sites now just touch
flood stage on Wednesday. Will continue the flood watches for
now, but if trends continue in the coming days the flood watches
may need to be cancelled.

&&

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

&&

$$

SHORT TERM...Cousins
LONG TERM...Cousins/Uttech
AVIATION...Uttech
HYDROLOGY...Gross