170
FXUS63 KDVN 172331
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
631 PM CDT Tue Sep 17 2024

.KEY MESSAGES...

- High confidence in above normal temperatures continues into
  Saturday.

- There continues to be lower confidence in the timing of rain
  chances late week into the weekend due to differences between
  the models.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 153 PM CDT Tue Sep 17 2024

Persistence forecasting as high pressure surface and aloft
remains anchored across our area.

Clear skies are forecast tonight with low temperatures ranging
from the lower 50s in far northwest Illinois to the lower 60s in
southeast Iowa and northeast Missouri.

Expect sunny skies again on Wednesday with highs in the mid to
upper 80s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 153 PM CDT Tue Sep 17 2024

The 500 mb pattern will transition from southwesterly flow aloft
as 500 mb ridging over the area finally breaks down allowing
for a transition to more zonal flow across the CONUS for late
week into early next week. This will usher in more active
weather Thursday night into early next week. A shortwave
passing to our northwest on Wednesday night into Thursday will
allow for increasing clouds on Thursday morning, but think that
the best lift and moisture will be well to our northwest leaving
the forecast dry. Thursday evening SPC has a Marginal Risk for
severe storms (Level 1 of 5) for portions of eastern IA.

Late week 500 mb ridging across the Plains begins to break down
resulting in amplified zonal flow across the CONUS with a
series of shortwave moving across the area Friday night into
early next week. However, there are timing and placement
differences between the different model runs as well as between
the GFS, ECWMF,and Canadian. This is resulting in daily chances
of showers and storms through the weekend into early next week.
Additionally temperatures cool to near normal by Sunday and
Monday with high temperatures in the 70s.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 628 PM CDT Tue Sep 17 2024

VFR conditions will prevail through the TAF period, with light
southeasterly winds between 4-8 KTs. No sig wx is expected at
this time.

&&

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

&&

$$

SHORT TERM...Haase
LONG TERM...Haase
AVIATION...Gunkel