854
FXUS63 KDVN 161906
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
206 PM CDT Mon Sep 16 2024

.KEY MESSAGES...

- High confidence on above normal temperatures this week.

- Confidence on timing of rain chances late week into the
  weekend is low, as an upper level ridge becomes reestablished
  across the region.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 204 PM CDT Mon Sep 16 2024

This morning`s sounding showed that there is significant dry
advection from previous days in our atmosphere, with notable dry
layers found near 700, 500, and 400 mb. Measured PWAT values are
down to 1.1", a drop from 1.6" just a day ago.  Despite this drying
out aloft, the low level moisture has been slow to drop, and dew
point values remain in the lower to mid 60s in much of the CWA,
except for the far east, which is now falling into the upper 50s. As
of 1 PM, temperatures are in the lower to mid 80s, and highs of
87 to 90 look on track.

The next 24 hours will continue to see a gradual drop in moisture,
with the boundary layer eventually seeing dew points in the 50s by
tomorrow morning, which could mix down to the low 50s Tuesday
afternoon!  Temperatures will be a degree or two colder tonight than
last with the dry advection, and lows in the upper 50s to near 60
are forecast. Highs Tuesday appear to reach the upper 80s to near 90
once again.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 204 PM CDT Mon Sep 16 2024

A lingering Rex block in the eastern CONUS is progged to finally
weaken early on, which is great news for our rain prospects right?!?
Unfortunately, likely not so at least early on in the period, as the
models quickly reestablish and amplify upper ridging over the region
Wednesday and Thursday ahead of a western CONUS trough, and possibly
longer. Trends from WPC cluster analysis of the 500 hPa pattern
support the influence of the upper ridge holding on longer. NBM has
pushed back PoPs to Thursday night through the weekend, but based on
the cluster analysis and trends of the 500 hPa ridge strength and
placement I wouldn`t be at all surprised to see further
delay/slowing of the PoPs. As a result, confidence remains low with
the timing of rain chances, until possibly sometime next weekend
when there`s a signal for the ridge shifting eastward allowing for
more influence of shortwave troughing. While timing of our next rain
chances remains low confidence, what remains high confidence is a
continuation of the unseasonable late summer warmth through at least
late week.  The 12Z WPC guidance now shows this weekend rain
potential more over our CWA, but time will tell.  There are many 12Z
GEFS members that keep our area dry through the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1212 PM CDT Mon Sep 16 2024

VFR conditions and light E/SE winds will continue to dominate
through the TAF period. The only cloud cover will be a few
diurnal (afternoon) high based cumulus around 5000-7000 ft,
followed by thin cirrus aloft.

&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin/McClure
AVIATION...Ervin