Moline, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

122
FXUS63 KDVN 282314
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
614 PM CDT Sun Jun 28 2026

.KEY MESSAGES...

- A prolonged period of hot and very humid conditions will
  expand area-wide Monday, highlighted by day-to-day peak heat
  index values of 100 to 110 and nighttime low temperatures no
  cooler than the mid 70s. Increasing potential to extend the
  Extreme Heat Warning through midweek.

- Thunderstorm chances will be limited tonight through midweek,
  with increasing chances Wednesday night onward (including the
  July 4th weekend), with the resultant cloud cover potentially
  having an impact on how high of temperatures but at least
  will remain very humid.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 240 PM CDT Sun Jun 28 2026

After thunderstorms depart the area by sunset, we will settle
into a true midsummer hot and very humid pattern. This is
characterized by an expansive and slightly retrograding 500 mb
high pressure ridge just to our southeast (591+ dm center), and
channeled low-level thermal ridge directly over the area (850
mb temps of 21-24C). Confidence is high in convective cloud
cover being limited over the area, though there is some model
signature for some cirrus Monday afternoon. The setup is also
not supportive of storms in the CWA through Wednesday morning,
and if they were to occur they would likely only be in the
northwest portion of the CWA (near/north and west of Cedar
Rapids) and during nighttime hours. In addition, confidence is
high in very warm nighttime lows, with NBM membership
probabilities over 70 percent of 75+ degree lows for most of
the CWA through Wednesday night. So their seems little that
would work against the going Extreme Heat Warning, issued
especially for persistence, and an increasing likelihood that
some or all of the CWA will see it extended through Wednesday.

The warm nighttime lows start tonight, thanks to 70-75 degree
dew points and a more southerly wind direction. That theme looks
to be consistent during the upcoming nights. For dew point
adjustments, have capped some of the NBM upper 70s to 80 dew
points to more mid 70s, which are more consistent with upstream
trusted observations. Also in line with that is the fact we are
still a little ahead of the peak evapotranspiration season (mid
July into early August). On the note of the winds, these will
be breezy again on Monday, with gusts of 20-25 mph, maybe
slightly higher at times. While that can nudge heat effects a
bit down when near thresholds, we are comfortably into the
multi-day extreme heat values (heat index of 105+). So that
should only offer a slight reprieve.

For Wednesday and even Wednesday night, the chances for
thunderstorms continue to ease, with the convective breeding
ground likely being the western Corn Belt region to Minnesota,
and steering vectors still favoring more of a northeast movement.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Issued at 240 PM CDT Sun Jun 28 2026

For this time period, confidence is high in continued very humid
air especially through Saturday. However, convective effects may
influence temperatures as the upper pattern flattens a bit over
the Upper Midwest and Corn Belt. Using ensemble means and
deterministic guidance, the current best convective potential
looks to be over the weekend as a short wave trough approaches.
That said, predictability at this distance is low, and some
noteworthy shifting such as MCS effects prior or a change in
trough passage timing certainly can occur. Otherwise,
synoptically the pattern of 850 mb temperatures of 20-22C
support high temperatures at least in the lower 90s, which would
mean heat index values into the 100+ range, and potentially
105-110.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 611 PM CDT Sun Jun 28 2026

Thunderstorms have departed to the east of the region, though in
the wake of northern storms, strong southeast winds continue
early this evening, along with some MVFR cigs. This period of
MVFR cigs and strong winds will lift north of the area by 02-04Z
this evening, leaving south winds and mainly VFR conditions into
Monday.

Through 02Z, expect some gusts to 30-35 kt. While gusts abate
after sunset, sustained winds should hold around 10 kt, maybe
higher at times. The setup also favors a 35-40 kt low-level jet
AOA 1.5 kft, and that is borderline for true LLWS development
given those sustained surface winds. If it occurs atop area
airports, 03Z-09Z is the most favored time.


&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Extreme Heat Warning from noon Monday to 9 PM CDT Tuesday for
     IAZ040>042-051>054-066.
     Extreme Heat Warning until 9 PM CDT Tuesday for IAZ063>065-067-
     068-076>078-087>089-098-099.
IL...Extreme Heat Warning from noon Monday to 9 PM CDT Tuesday for
     ILZ001-002-007-009-016>018.
     Extreme Heat Warning until 9 PM CDT Tuesday for ILZ015-024>026-
     034-035.
MO...Extreme Heat Warning until 9 PM CDT Tuesday for MOZ009-010.

&&

$$

SHORT TERM...Friedlein
LONG TERM...Friedlein
AVIATION...Ervin