722
FXUS63 KDVN 272328
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
628 PM CDT Thu Mar 27 2025

.KEY MESSAGES...

- There is a Marginal Risk (level 1 of 5) for severe weather
  late this evening/early Friday, with large hail the main
  hazard.

- Warm and windy Friday, with near record highs and wind gusts
  nearing advisory levels. In addition, there is an elevated
  fire danger risk Friday afternoon.

- Warm start to the weekend, then turning colder Sunday and into
  next week.

- Active weather returns early next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 235 PM CDT Thu Mar 27 2025

Much of the shower activity has diminished, but still lingers
in our far east and south attendant to a passing weak wave
and a veered LLJ and elevated moisture transport. The
westerly LLJ and moisture transport linger into this evening,
thus we could keep festering a few showers particularly south
this evening. Later this evening and especially overnight/early
Friday, expect a burgeoning of showers and storms with the
ramping LLJ atop a northward lifting surface warm front. Deep
layer shear of 30+ kts and modest elevated instability in the
growth zone will support a hail risk possibly to the size of
quarters or a little larger in isolated instances, and we
remain in a Marginal risk or level 1 out of 5 for severe
weather from SPC.

On Friday, any residual shower/storm activity should depart by
mid morning as the surface warm front lifts north. We`ll
be thrust into the warm sector with a strong H85 southwesterly
flow advecting in an anomalously warm airmass with temps around
16C (near the daily max for the day per SPC climatology). This
combined with decreasing cloudiness/increasing solar insolation
will boost temperatures into the mid 70s to lower 80s, which will
be near high temp records for the day. Please see our climate
section below. In addition, a strong pressure gradient combined
with mixing down strong winds at the top of the mixed layer in
the afternoon (40+ kts) will bring strong southwest winds
gusting up to 45 mph at times. This is near wind advisory
criteria, and may necessitate a headline. Also, the warm temps
and windy conditions combined with the very dry fuels will bring
elevated fire danger. GFDI values top out in the high to very
high category for a few hours in the afternoon. We could need
headlines for the fire danger as well.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 235 PM CDT Thu Mar 27 2025

Friday Night...Sub 997mb surface low to track from southern MN
to northern MI and weaken. This combined with BL decoupling will
allow the strong winds to subside. Showers and storms are
favored mainly to our northwest along a cold front, but some
weakening activity could move in late Friday night/early
Saturday morning (20-30% chance) for areas north/west of the
Quad Cities. It will be a rather mild night with lows only
dropping into the 50s.

Saturday an Sunday, despite 00z deterministic and ensemble
model differences in surface low tracks, southwest flow aloft
and warm 850mb temps will bring another warm and mostly dry day
to the CWA on Saturday before fropa Saturday night. Highs in the
upper 60s/low 70s are forecast. A strengthening LLJ and
convergence along surface front Saturday night to support
shower/storm activity across the MO RVR valley that tracks east
across IA overnight in a weakening phase as it approaches the
CWA. Still, some precipitation is expected to reach eastern IA
early Sunday and with steep mid level lapse rates and 35-45kt
deep layer shear can`t rule out some cells producing some large
hail/near-severe winds. As a result, SPC has a Marginal Risk
for severe weather for most of the area on Saturday. Behind the
fropa, much cooler temperatures and breezy north winds are
expected Sunday. With the main front and baroclinic zone
expected to our south and east, the severe risk has also shifted
south out of our CWA. In fact, the ECMWF shift of tails for
CAPE-Shear would suggest the area of concern would be southern
MO/northeast AR and into the OH RVR valley on Sunday. So the
main story Sunday will be some lingering showers in the AM, with
CAA occurring making for a brisk day and challenging
temperature forecast.

Sunday Night, considerable uncertainties exist on whether or
not enough moisture and forcing will remain with incoming cold
air to produce any snow on the back side of the system. 12z
deterministic ECMWF is suggesting a secondary deepening low
rippling up to our east that would bring more moisture and an
increased potential for at least light snow accums to portions
of E Iowa and NW Illinois. Still a ways out but this potential
is something to monitor.

Early Next Week, broad upper level ridge and surface high to
pass overhead bringing a period of dry and cooler conditions.
Two upstream trofs to move across the Pacific northwest and
western CONUS to induce another strong surface low to the lee of
the Colorado Rockies late Tuesday and Wednesday bringing more
precip chances, warmer temperatures, and strong winds to the
Midwest.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 619 PM CDT Thu Mar 27 2025

A mainly VFR cigs can be expected this evening with south to
southeast winds at 8 to 12 kts. In 3Z to 9z window later
tonight, a warm front aloft will sweep through the area with a
chance around 30-50% for scattered thunderstorms with temporary
MVFR conditions. Also overnight, increasing strong winds aloft
will create a long period of LLWS, as winds are southeast 10
kts, and around 2000ft AGL, are southwest around 40 kts. This
condition will diminish towards daybreak, as surface winds
couple with winds aloft and increase into the 20 to 30 kt
range. This warm south/southwest wind will last from 14Z Friday
through sunset Friday evening.

&&

.CLIMATE...
Issued at 235 AM CDT Thu Mar 27 2025

Record High Temperatures:

Friday March 28:
KBRL: 84/1910
KCID: 81/1968
KDBQ: 78/1910
KMLI: 81/1910

Record High Minimum Temperatures:

March 28:
KMLI: 53/1879

March 29:
KMLI: 60/1910

&&

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

&&

$$

SHORT TERM...Gross/McClure
LONG TERM...Gross/McClure
AVIATION...Ervin
CLIMATE...Gross