077
FXUS63 KDVN 021459
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
959 AM CDT Sun Jun 2 2024

.KEY MESSAGES...

- An active, summer-like pattern will be found through early
  week, with warm/muggy conditions and multiple rounds of
  showers and storms. Monday PM and Tuesday PM/night will be
  monitored for strong to severe storms.

- Mainly dry mid week to late week with seasonal temperatures.

&&

.Update...
Issued at 1000 AM CDT Sun Jun 2 2024

We cleared out the dense fog advisory around 830 AM this
morning as the fog had lifted in all areas except for northern
valley sites. The stratus may continue to plaque our forecast
through early afternoon in the wake of the fog event, and I`ll
be looking at potentially lowering highs today...which might
actually make it a more pleasant afternoon.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 325 AM CDT Sun Jun 2 2024

Surface to 850 hPa ridge is building in early this morning. The
light to calm surface winds, low level moisture aided by recent
rainfall, and clearing stratus has allowed fog to form near and
especially west of the Mississippi River, which has become
dense in areas. Further east into northwest Illinois, still
hanging on to weak cyclonic flow with satellite and obs showing
more in the way of stratus than fog. However, as the ridge
builds in we could see more in the way of fog develop in these
areas around daybreak should the stratus decrease. Little in
the way of mixing for much of today and a little cirrus atop may
allow the fog and/or stratus to hang around into the late morning.
Following the lifting of the fog, a partly cloudy and seasonable
conditions are on tap with highs in the upper 70s to lower 80s and
moderate humidity.

Late this afternoon into evening, we can`t rule out some spotty
convection in portions of E Iowa and NE Missouri as remnant AM
Central Plains activity and possible attendant MCV shifts east.
This potential currently looks isolated (<20%) for mention given
mid level ridging still largely in control. However, pending
convective trends out west if a stronger MCV were to occur then
will need keep an eye out for possibly needing low mentionable PoPs
into our western service area.

Better prospects for showers and some storms will occur overnight
into Monday AM, with a veering nocturnal LLJ and attendant warm/
moist advection and elevated convergence coupled with lift from low
amplitude shortwaves in zonal flow aloft.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 325 AM CDT Sun Jun 2 2024

A potential MCV tied to the early Monday convection could foster
some potential for redevelopment of showers/storms by afternoon,
especially in the south/east portions of the service area. Any
Monday PM convection would need to be monitored for organized
multicell clusters capable of strong gusty winds and small hail.
This threat is conditional upon timing of the wave, and notable
augmentation to the deep layer shear in the presence of moderate
instability (MLCAPE progged around 1500+ j/kg).

Otherwise, largely south/southwest low level flow/ warm advection
will foster above normal warmth, which coupled with increasing
humidity will make it feel very summer-like through early
week.

Toward mid to late next week the guidance continues to support
a pattern change with an eventual deepening northern stream
trough shifting into the eastern CONUS. An initial shortwave
driving this pattern change will evolve eastward across the
Northern Rockies and along the International border with ND/MN
Tuesday into Wednesday. This will drive a cold front through
the area Tuesday night into Wednesday bringing the potential
for strong storms in the presence of above normal warmth and
pooling low level moisture and instability. The deterministic
ECMWF has stayed fairly consistent over the past several
nights painting in the QPF the look of a mature MCS developing
to our northwest on Tuesday, and then propagating E/SE into
the reservoir of instability and deeper moisture across
the region Tuesday night. This would most certainly harbor
strong wind potential given ramping deep layer shear. However,
there is a lot of uncertainty as well and this is largely
attributed to the fact that we`re seeing more of a signal that
showers and storms could be around the area for much of the
day on Tuesday, which if occurs could limit instability and
temper subsequent strength of any convection Tuesday night with
the cold front. Bottom line, there is at least some potential
for strong storms Tuesday/Tuesday night that we`ll continue to
re-evaluate in the next couple of days. Stay tuned!

The cold front will begin the process of ushering in a cooler
airmass, which will be reinforced by an upper trough evolving
over the Great Lakes and eastern CONUS by late in the week
and heading into next weekend. This is likely to result in
mainly dry conditions, and below normal temperatures with pleasant
days (highs mainly in the 70s) and cool nights (lows in the 50s
to possibly a few 40s).

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 528 AM CDT Sun Jun 2 2024

MVFR to VLIFR conditions in fog and/or low clouds will give way
to VFR conditions by late morning and early afternoon. There
is a low chance (15-30%) for a shower or storm west of the
Mississippi River 22z-03z. Better chances (40-70%) for showers
and some storms will occur late tonight with a veering nocturnal
LLJ. MVFR to IFR conditions can be expected with the storms.

&&

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

&&

$$

UPDATE...Ervin
SHORT TERM...McClure
LONG TERM...McClure
AVIATION...McClure