189
FXUS63 KDVN 151730
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1230 PM CDT Sun Sep 15 2024

.KEY MESSAGES...

- Mainly dry with a continuation of late summer warmth (highs
  5-10+ degrees above normal) for much of the week ahead.

- Low chance (15-25%) for showers/storms again later today into
  early evening.

- Low confidence with rain prospects and timing heading into
  next weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 245 AM CDT Sun Sep 15 2024

The weather pattern remains stagnant due to an upper level Rex
Block to our east, formed by eastern Great Lakes to Mid-
Atlantic ridging and weakening remnants of TC Francine over
portions of the Mid-South. Meanwhile, south to southwest flow
prevails aloft across the region with upper troughing along
the West Coast.

A moisture axis (PWATs around 1.5+ inches) lingers across the
region on the western periphery of the Great Lakes ridge, and
may once again foster isolated/widely scattered convection
later today into early evening with aid of convective temps
(mid 80s) being breached and weak mid level vorticity advection.
These low rain chances (15-25%) would appear to favor near and
especially west of the Mississippi River within a mid level
theta-e gradient. Severe weather is not expected, but there
could be some gusty winds.

With more solar insolation today and little change thermally
I would anticipate similar highs to those of Saturday or even
a bit warmer in some areas, with more widespread mid/upper 80s
and even a couple sites possibly touching 90 degrees yet again.

Any convection should gradually diminish with sunset, leaving
behind mainly clear to partly cloudy skies. Slightly drier
air advection on light easterly winds and good radiational
cooling should get lows down into the range of 60-65 with a few
upper 50s possible.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 245 AM CDT Sun Sep 15 2024

Not seeing a whole lot of change in the pattern throughout the
week ahead, as we continue to see a blocky pattern to our
east with a Rex Block lingering early in the week that will keep
ridging influence over the region. That said, isolated
diurnally driven convection can`t be totally ruled out,
particularly again on Monday PM west of the Mississippi River
within the residual mid level theta-e gradient. Beyond, another
warm core low (potential tropical cyclone formation) is expected
to develop off the Mid-Atlantic coast. This will reinforce the
Rex Block and keep the pattern stagnant, with mainly dry and
summer warmth conditions heading into late week. There is some
potential for the Rex Block to break down by next weekend, which
would allow for rain chances to return as a western trough makes
inroads. However, confidence is low on just when rain chances
may make a return due to 1) blocky nature of the pattern and
uncertainties on when it will break down and 2) indications of
a more meridional jet configuration ahead of an ejecting waves
from the western trough, which would tend to favor more widespread
precipitation staying well to our west and decaying/weakening
further eastward toward our area being under the influence of more
subsidence.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1227 PM CDT Sun Sep 15 2024

Diurnal convection is again expected through 01z/16 across
mainly eastern and southeast Iowa. No SHRA/TSRA were included in
the 18z TAFs as the probability of a TAF site being impacted is
5 percent at best. Another round of even more isolated SHRA/TSRA
is expected after 18z/16 in southeast Iowa. Otherwise VFR
conditions will continue.

&&

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

&&

$$

SHORT TERM...McClure
LONG TERM...McClure
AVIATION...08