632
FXUS63 KDVN 312322
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
622 PM CDT Sun May 31 2026

.KEY MESSAGES...

- There is a 20 - 30 percent chances of showers and isolated
  storms through Monday with the better chances at night.
  Widespread rainfall is not expected.

- The blocking across the CONUS is forecast to break down late
  this week with a return of low chances of showers and storms.
  Once again, widespread rainfall is not expected.

- The lack of rain and overall low chances of rain during the
  coming week is expected to result in an expansion of the
  abnormally dry conditions with increased probability of
  moderate drought developing.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 154 PM CDT Sun May 31 2026

Convection will persist along another theta e gradient running from
northeast Iowa into central Illinois through sunset. Slightly higher
low level moisture combined with differential heating will allow
isolated to low end scattered (15-25%) diurnal convection to develop
across the remainder of the area. Once sunset occurs the diurnal
convection will quickly dissipate as the support for it moves into
Wisconsin.

The very short term models differ on the prospects of seeing late
night nocturnal convection. The better signal for this is in central
and southern Missouri. However, there is a weak disturbance coming
out of Nebraska that has a low (20%) probability of developing
nocturnal convection that moves through the area well after
midnight and into the morning commute.

If this scenario does occur, the convection would be in a decaying
phase as it reaches eastern Iowa as it outruns the better moisture
across western Iowa.

Any nocturnal convection across the area after sunrise Monday will
quickly dissipate during the morning commute. Weak boundaries left
over from the nocturnal convection would provide the focus for
diurnal convection to develop Monday afternoon.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 154 PM CDT Sun May 31 2026

Thursday through Sunday
Assessment...a certainty (>95%) of above normal temperatures

The new model runs quickly break down the omega block the second
half of the week leaving a relatively flat ridge over the central
CONUS. The net result will be a continuation of the above normal
temperatures.

As expected the model consensus is slowing down the arrival of
precipitation. Thursday is now dry and there is a negative delta on
pops for Thursday night given the dryness of the atmosphere. Several
deterministic runs suggest a dry Thursday night. Given the lack of
moisture I expect pops for Thursday night to continue dropping as
the week progresses.

Integrated Vapor Transport really does not begin increasing until
Friday and especially Friday night. The best chances for rain look
to be Friday night when the IVT is progged to be maximized. The
model consensus concurs with a 40-60% chance for rain Friday night.
Outside of Friday night, the model consensus has 20-40% chances for
rain from Thursday night through Sunday. HOWEVER, not everyone will
see rainfall. Convection would have a diurnal trend to it with the
higher pops occurring during the afternoon into early evening hours.

Although there are chances for rain late this week, the abnormally
dry conditions have a high (>80%) probability of continuing with a
low (15-30%) probability of moderate drought conditions developing
over the next 10-14 days.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 614 PM CDT Sun May 31 2026

Light east flow will trend northeast overnight, but remain under
10 kts. Scattered to broken mid and high clouds will continue,
with a very low (10-20%) chance of an isolated shower this
evening, overnight and again Monday. There does appear to be
enough signal for showers/storms over Missouri late tonight,
that BRL could be brushed by some showers 09z to 13Z.

Otherwise, the dry air should again win out over rainfall the
next 24 hours in general, and TAFs will be VFR predominantly.

&&

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

&&

$$

SHORT TERM...08
LONG TERM...08
AVIATION...Ervin