723
FXUS63 KDVN 050531
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1231 AM CDT Sat Oct 5 2024

.KEY MESSAGES...

- Unseasonably warm (possibly near record highs for some)
  Saturday and breezy/windy owing to elevated fire danger for
  unharvested crop fields.

- Low chance (20%) for showers Saturday evening north of Hwy 30.
  Any showers could enhance wind gusts possibly over 50 mph.

- A prolonged period of mainly dry weather is still on track
  through next week. This could worsen the ongoing drought in
  some areas and also result in larger than normal diurnal
  temperature swings.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 312 PM CDT Fri Oct 4 2024

The cold front, which brought welcomed rainfall to portions of
SE Iowa and WC Illinois (where pockets of 0.5 to over 1" were
observed) and also a few marginally severe storms with hail,
is becoming stationary near the I-70 corridor. This front will
lift back northward as a warm front late tonight and Saturday,
ushering in unseasonably warm air. This will likely be
accompanied by a period of low/mid cloudiness. Can`t also
rule out a brief light shower or some sprinkles with the
isentropic ascent. A few CAMs do show some lower 20-30 dbz in
their reflectivity depiction, but when looking at soundings the
moisture layer looks rather shallow and feeling this is mostly
clouds although will need to monitor for any changes in moisture
depth that could allow for some mention. Otherwise, lows tonight
are a bit challenging and will be modulated by cloud cover and
timing of their arrival. In general the milder lows (upper 50s
to around 60) are expected south where clouds out there already in
some areas are anticipated to expand/develop first tonight.
Cooler lows should be found north (upper 40s and lower 50s)
where clouds will arrive here last. Winds may also turn gusty
at times from the E/SE to 20 kts or so late this evening and
overnight.

On Saturday, the warm front will lift through during the morning
sweeping the clouds out with its passage. This will usher in
unseasonably warm air and it`s still looking like the warm air
advection will produce values well up in the 80s for highs.
Progged 925 hPa temperatures remain in the general range of 22C
to 25C by 00z Sunday, which mixed dry adiabatically to the
surface would yield highs of 84-89F and possibly near records
for some (see Climate section below). If we were to mix deeper
then more widespread upper 80s to lower 90s would be likely, and
this is possible especially with full solar insolation during
the afternoon and a favorable warming S/SW wind that will be
gusty at times of 30 to 40 mph.

The last few runs of the NBM continue to back off on rain
chances Saturday evening, as a stacked low pressure looks to
track north of Canadian border along with the main dynamics
or forcing. That being said, we`ve held onto some low PoPs
(20%) north of the Hwy 30 corridor for Saturday evening with
convergence along an attendant cold front and a glancing shot
of mid level vorticity advection. Something to keep an eye on
is the potential for any elevated showers to mix down some
stronger winds potentially over 50 mph given near 50 kts atop
the mixed layer and presence of an inverted V signature in the
soundings with considerable sub-cloud dry-air.

This unseasonably warm and breezy/windy day will lead to a
very high fire danger day in cured unharvested crops, but there
remains a signal of some surface dew point advection/increase
and higher RH that may limit the potential for true Red Flag
Warning criteria. Nonetheless, any adjustments to temps
(warmer), dew points (lower) and winds (higher) can push us more
into RFW criteria, so we`ll want to pay close attention to obs
and trends for any changes.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 312 PM CDT Fri Oct 4 2024

Behind this frontal passage, cooler and breezy conditions look on
tap for Sunday with ongoing field fire potential remaining,
especially with lower humidity that day despite the cooler
temperatures.

Beyond that, much if not all of next week looks to be quiet and
dry governed by initially a large expanse of surface high
pressure early week followed by strengthening mid level ridging
mid to late week. This should also foster large diurnal swings
with cool nights, many in the 40s, and above normal highs in the
70s to near 80 on a few days.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1231 AM CDT Sat Oct 5 2024

VFR conditions are expected to prevail throughout the TAF
period. The main focus for today will be on the winds, which
will start out from the southeast early this morning but
gradually turn more southerly with time. During the daylight
hours, winds will strengthen with a very favorable environment
to mix down stronger winds from aloft to the surface. Gusts
today will likely reach between 25 to 35 knots, peaking this
afternoon to coincide with the best mixing. A largely dry cold
front will then sweep through the area this evening, which will
turn the winds more from the northwest in its wake. Just ahead
of the front, a stout 50+ kt southwesterly low-level jet will
develop, which will support a brief period of low-level wind
shear for some.

&&

.CLIMATE...
Issued at 302 PM CDT Fri Oct 4 2024

Record High Temperatures October 5:

Burlington   89/2007
Cedar Rapids 89/1963 and previous years
Dubuque      87/1922
Moline       89/1922

&&

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

&&

$$

SHORT TERM...McClure
LONG TERM...McClure
AVIATION...Schultz
CLIMATE...McClure