048
FXUS63 KDVN 311006
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
506 AM CDT Fri May 31 2024

...Updated for 12z Aviation...

.KEY MESSAGES...

- Mainly dry and continued pleasant today.

- Chances for showers (30-70%) tonight (and possibly a few
  storms) lingering into Saturday.

- Active pattern next week, with near daily chances for showers
  and storms. May have to watch Tuesday into Wednesday for a
  chance of stronger storms.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 316 AM CDT Fri May 31 2024

Another pleasant day is in store for the area today with lower
humidity compliments of low level E/SE flow advecting in drier
air from Ohio Valley high pressure. There are very low chances
(10-15%) for a stray shower/sprinkles in our far west with some
glancing low/mid level theta-e advection, but the brunt of any
measurable precipitation potential will reside to our west/south
during the daylight hours. We`ll see some mostly filtered
sunshine at times with high level clouds, and potentially
transitory bouts of opaqueness in some mid clouds especially
south/west closer to the theta-e advection. Highs will be
modulated by the cloud cover and extent of solar insolation,
but overall look to be seasonable and range from the mid 70s to
lower 80s.

Tonight into Saturday, the area looks to be split between
stronger forcing attendant to a passing mid level shortwave to
the south across portions of the Mid-Mississippi and Ohio
Valleys, and a stronger wave traversing the International
border with MN/ND. Despite this, sufficient mid level forcing
and moist isentropic ascent overspreads the area to aid
increasing precipitation chances (30-70%). Instability looks
rather limited but sufficient for perhaps a few rumbles of
thunder, but largely anticipate showers. As such, rain amounts
should be mostly light and both GEFS and ECS probabilities for
0.5 inch or more of rain this evening to Saturday evening are
10-40%. Better coverage of precipitation Saturday looks to be
the first half of the day, with chances lowering to 15-30% in
the afternoon and possibly lingering early evening pending the
timing of a secondary weaker mid level wave.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 316 AM CDT Fri May 31 2024

A brief bout of 850 hPa ridging builds in Sunday making for
largely dry conditions. However, by Sunday night the high
will quickly retreat and isentropic lift will rapidly
strengthen ahead of an emerging shortwave in the Central Plains.
The brunt of the low level jet and attendant advection and
convergence looks to focus mainly to our west, but nonetheless
will expect shower and storm chances to ramp up late Sunday
night through Monday AM with a veering jet and passing shortwave.

For much of early to mid next week the pattern looks to become
predominantly fast zonal. This will keep the weather active
across the region, as multiple disturbances are shuttled quickly
in the flow. There is considerable differences in timing,
strength and placement of these waves in deterministic and
ensemble guidance, as to be expected given many of these are low
amplitude. As a result, we continue to have many days of broad-
brushed and higher PoPs while in reality it favors smaller
windows or time periods of high PoPs with still many dry hours.
A stronger mid level shortwave by mid next week may provide the
opportunity for some stronger storms Tuesday into Wednesday.

Beyond that, it looks to turn cooler while remaining unsettled
heading into late next week and next weekend, as the
preponderance of the deterministic and ensemble guidance
supports a cut-off low traversing the Midwest and Great Lakes
regions. This will foster continued periodic chances for
showers, as spokes of energy rotate around the low. The clouds
and eventual northwest flow aloft will favor cooler conditions.
The Climate Prediction Center (CPC) Week 2 temperature outlook
for June 7-13 has probabilities (40-50%) leaning toward below
normal temperatures.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 500 AM CDT Fri May 31 2024

VFR conditions are expected to persist into this evening.
Later this evening and overnight, an approaching weather
system will bring chances (30-60%) for showers. An isolated storm
can`t be ruled out (20% chance). Predominantly VFR conditions are
expected with the showers, with a chance (30-40%) for MVFR conditions
(mainly for visibility) in the stronger showers and isolated storms.
Easterly winds will turn more from SSE and increase to 10-15 kts
by late morning and afternoon, with locally higher gusts near 20 kts
possible. Tonight, winds will be from ESE at 5-10 kts.

&&

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

&&

$$

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