488
FXUS63 KDVN 210010
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
710 PM CDT Sat Jul 20 2024

...Updated for 00z Aviation...

.KEY MESSAGES...

- Pleasant summer weather is forecast this weekend with low
  chances for isolated showers and storms. Much of the area
  should stay dry through Sunday.

- Increasing humidity next week will lead to occasional chances
  for scattered showers and storms Monday through Wednesday.

- Moderate to major river flooding continues on the Mississippi
  River. Moderate flooding on the Rock River at Joslin and
  Moline.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 232 PM CDT Sat Jul 20 2024

At 2 PM, surface high pressure sits across the area. Isolated
showers been occurring west of a Cedar Rapids to Mount Pleasant
line today with the rain showers quickly diminishing, as they
encounter dry air evident on the 12z DVN sounding this morning
as they move to the east. Winds are light and variable.
Temperatures ranged from 73 degrees at Mount Pleasant to 80
degrees at Moline.

A 500 mb shortwave trough moving through a longwave trough to our
northeast will move into eastern Iowa and northwest Illinois
and rewmain through the day on Sunday. This will result in
isolated showers or sprinkles and thunderstorms this afternoon
into the early evening northwest of Cedar Rapids. On Sunday
there are low chances of showers and storms across most of the
area along and west of the Mississippi River. There will be a
slight uptick in low level moisture on Sunday as dewpoints climb
into the lower to mid 60s areawide. Severe thunderstorms are
not expected with weak wind shear across the area. Rainfall
amounts are expected to be light with a tenth of an inch or less
expected. High temperatures on Sunday will be in the upper 70s
to lower 80s across the area.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 232 PM CDT Sat Jul 20 2024

Temperatures next week are forecast to be closer to normal for
mid to late July with high each day in the lower to mid 80s. Low
temperatures each day will be in the lower to mid 60s.

Eastern Iowa, northwest Illinois, and far northeast Missouri are
forecast to remain on the southwestern edge of 500 mb longwave
trough with a closed upper level low sitting over southeastern
Canada through the week before high pressure builds in on Thursday
and Friday. This will result in chances of scattered showers and
thunderstorms each day with chances in the late morning through
early evening hours before instability dissipates with the loss of
daytime heating. The best chances of showers and storms in the
next 7 days looks to be on Wednesday. Chances of severe storms
remains low as deep layer shear remains week.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 700 PM CDT Sat Jul 20 2024

Shower chances and visibility restrictions from fog will be the
main concerns this TAF cycle. A mid/upper level low pressure
system over north central Iowa is forecast to meander slowly
into southern portions of the service area by Sunday evening.
Weak lift associated with this feature will keep some spotty
shower potential through the period. Probabilities appear to
be too low (10-20%) for any mention. Sunday afternoon, a
backdoor cool front may approach from Wisconsin and provide
additional focus for showers and storms particularly at the
northern sites (DBQ and CID), however there`s a lot of
uncertainty on the location of the boundary that precludes any
higher probabilities and mention at those sites for now.
Aside from that, very weak flow and increasing low level
moisture will bring the potential for MVFR to IFR fog at the
terminals overnight into Sunday morning (06z-13z). The greatest
potential appears to be at CID within a corridor of higher dew
points in the mid 60s. At CID, a period of visibility of
LIFR/VLIFR 09z-13z is possible, however potential for cloud
cover lends to lower confidence on going near minimums for
visibility at this time.

&&

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

&&

$$

SHORT TERM...Cousins
LONG TERM...Cousins
AVIATION...McClure