442
FXUS63 KDVN 110019
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
719 PM CDT Sat Aug 10 2024

.KEY MESSAGES...

- Below normal temperatures expected through at least early next
  week, before moderating closer to normal by the end of next
  week.

- Rain chances return late Sunday night/Monday with periodic
  chances continuing next week.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 142 PM CDT Sat Aug 10 2024

Picture perfect sensible weather is in place today, and we hope
you`re reading this AFD from a mobile device outside, because
it`s outstanding out there! Afternoon temperatures have reached
the lower 70s with dewpoints in the lower to mid 50s, while the
sky has a thin mix of cumulus and blue sky. Again, it`s picture
perfect!

The northwest winds will decrease this evening, to under 10 mph
by mid evening, resulting in another cool and nearly calm
night. A subtle ridge of surface high pressure will move over
the area by sunrise, which could allow a short period of calm
winds toward morning, with lows in the lower to mid 50s. After
this high moves south tomorrow morning, west winds will bring in
slightly warmer air, though dewpoints should remain in the 50s.
Thus, Sunday will be a touch warmer, in the upper 70s to lower
80s, but should once again feel exceptionally pleasant.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 255 AM CDT Sat Aug 10 2024

The pattern aloft begins to undergo change late in the weekend, as
a deep upper low in Ontario/Quebec begins to finally shift
eastward. This occurs as an upstream kicker shortwave trough
translates southeastward from the Northern Rockies reaching the
Upper Midwest by Monday morning. There is a signal in the model
guidance for one or more convective systems forming to our
west Sunday night, one to our southwest across portions
of the Central Plains along/north of an evolving warm front and
surface low likely tracking ESE. The other may evolve further
north into parts of South Dakota, SW Minnesota, W Iowa within
elevated theta-e advection ahead of the shortwave. The
convection should be decaying/weakening as it moves into our
area late Sunday night and Monday morning, but at least some
showers and perhaps a few embedded storms are expected with the
highest chances (40-60%) across the southwest 1/3-1/2 of the
county warning area. Between the precipitation and cloud cover
highs should be limited into the 70s on Monday across the region.

The pattern looks to be somewhat active through the rest of next
week and into next weekend, as upper level ridging builds into the
Plains. Monsoonal sub-tropical moisture will flow on the western
periphery of the ridging initially, but precipitation chances
will return/ramp up midweek as some of this moisture traverses
the northern periphery of the ridging along with several embedded
perturbations /ridge riders/ traversing north of a surface
boundary to our south. PWATs increasing over 1.5+ inches by
Wednesday into Thursday coupled with favorable jet dynamics
supporting/enhancing large-scale lift suggests this period
mentioned will be one to watch for heavy rain potential, and
while the pattern doesn`t scream severe weather it has at least
some potential which will need to be monitored.

By the end of next week into the start of next weekend there is
a lot of uncertainty in the pattern, but seeing some signal
in some of the ensemble and deterministic guidance of a trough
moving through the region. This could be progressive and bring
a 24+ hour period of PoPs late in the period, or as some guidance
hints it could develop into a closed low which could impact
the forecast in prolonging PoPs and lowering high temperatures,
so stay tuned as the details become better defined in the days
ahead.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 713 PM CDT Sat Aug 10 2024

VFR will prevail through the period with unrestricted low-level
visibility and light winds.

&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...McClure
AVIATION...Uttech