185
FXUS63 KDVN 080041
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
741 PM CDT Tue May 7 2024

.KEY MESSAGES...

- There is a marginal or level 1 out of 5 risk for severe
  storms on Wednesday.

- An active pattern continues through early next week with
  chances of showers and storms every 24 to 36 hours.

- Below normal temperatures are expected Thursday through Saturday
  with a warming trend starting early next week.

&&

.UPDATE...
Issued at 733 PM CDT Tue May 7 2024

Convection in central Iowa is being supported by an upper level
disturbance in northwest Iowa and another across southern
Nebraska. Trends with the very short term models suggest that
the central Iowa convection will maintain through much of the
evening before slowly dissipating.

Based on reports from central Iowa, the convection will still
be capable of producing isolated wind gusts of 40-50 mph all the
way to the Mississippi River before the convection dissipates.

The forecast is currently being updated to reflect this
scenario.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 209 PM CDT Tue May 7 2024

Eastern Iowa, northwest Illinois, and far northeast Missouri sit
in the clear air ahead of a cold front that will move across the
area this afternoon. A prefrontal wind shift to the southwest is
near the Mississippi River. Temperatures through 1 PM are in
the mid to upper 60s. Dewpoints are in the upper 50s to lower
60s.

The cold front currently moving across the area is forecast to
move to our south and east tonight before stalling across
southern Missouri as the front becomes parallel to the flow
aloft. Models show a subtle shortwave ridge that will move
across the area tonight. A few showers and storms are possible
east of the river late this afternoon into the early evening.
Skies will remain clear overnight with light winds. Low
temperatures tonight are forecast to be in the lower to mid 50s.

On Wednesday, a closed 500 MB low is forecast o rotate into
western Iowa as a surface low rides along the old cold frontal
boundary. There is disagreement between the synoptic models
about how far north the surface low tracks and how far north the
warmer air and instability come. Forecasting soundings across
the area show the best shear and instability is in the lower
part of the atmosphere looking like the potential for low
topped convection especially south of a Fairfield to Galesburg
line. A marginal risk of severe storms is in place for the
entire area. The window for the risk is narrow and looks to be
during the late morning into the early afternoon. Large hail and
damaging winds are the main threats but there is also the
threat for a tornado or two if winds at the surface are backed.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 209 PM CDT Tue May 7 2024

Broad troughing continues across the area through the day on
Thursday with scattered showers and storms possible through the
day. After Thursday, the flow aloft becomes more northwesterly
with a series of ridges and troughs moving across the Upper
Midwest. This results in chances of showers and storms every 24
hours or so.

High temperatures are forecast to be below normal Thursday
through Saturday before a general warming trend begins next
week.

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1240 PM CDT Tue May 7 2024

A cold front is forecast to move eastward across the eastern
Iowa TAF sites early this afternoon. Conditions will quickly
improve to VFR behind the front as MVFR ceilings clear.
Showers and storms may develop in the vicinity of KBRL and KMLI
through 21 UTC before the threat shifts to the east of the
area. Southwesterly winds are forecast to diminish after 00
UTC.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 617 PM CDT Tue May 7 2024

Convection associated with the cold front will push through
northern Illinois through 06z/08. Very short term models take
the convection in central Iowa into eastern Iowa by 06z/08
before dissipating. No TSRA/SHRA were included in the 00z TAFs
as the current probability of a TAF site being impacted is 10
percent at best. Otherwise expect VFR conditions.

&&

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

&&

$$

UPDATE...08
SHORT TERM...Cousins
LONG TERM...Cousins
AVIATION...08