000
FXUS63 KDVN 240518
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1218 AM CDT Wed Apr 24 2024

.KEY MESSAGES...

- Isolated showers and thunderstorms remain possible in far
  eastern and southeastern portions of the region.

- Colder air returns midweek with frost and a brief light freeze possible
  Wednesday night in northern IL.

- Turning warmer and active by the end of the week through the
  upcoming weekend, with potential for rounds of showers and
  storms. Severe weather and heavy rain are possible.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 306 PM CDT Tue Apr 23 2024

A sharp dewpoint gradient exists from southeast to northwest
across the forecast area this afternoon. The primary frontal
wind shift runs from west of KVYS to near KEOK as of 20Z. Along
and southeast of the front isolated showers and thunderstorms
will be possible. The front should clear the area by 6 PM. The
latest CAM data is not showing much, if any, thunderstorm
activity, but with dewpoints hanging in the 50s, we will keep
the mention going.

Behind the front, gusty northwest winds and low relative
humidity will create an elevated fire danger through sunset.

Northwest flow aloft will continue through the short term
period. Surface high pressure will build southward over the
region tonight and then shift eastward Wednesday and Wednesday
night. Temperatures will be near or a bit below normal levels
with the coldest highs Wednesday and coldest lows Wednesday
night. The NBM has temperatures dropping to and just below
freezing in northwest Illinois. We maintained the mention of
areas of frost over northwest Illinois and adjacent portions of
Iowa, but with winds expected to stay up above 5kts all night,
frost seems a like a stretch at this time.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 306 PM CDT Tue Apr 23 2024

High pressure aloft will briefly build over the forecast area
Thursday, and then continue east, allowing southwest flow to
develop Thursday night. An occluded storm system will lift from
the central Plains Thursday night to western Ontario by
Saturday. Anomalously low surface pressure will lead to strong
warm, moist advection Friday into Saturday.

Elevated showers and thunderstorms will spread northeast across
the region Thursday night into Friday. Surface-based
instability may develop late Friday and Friday night as a warm
front approaches and eventually passes. Good chances of showers
and thunderstorms will continue and a few strong to severe
storms cannot be ruled out, especially over the southwest half
of the forecast area.

The associated surface front will likely be draped somewhere
across the region Saturday through Sunday, when another storm
system lifts northeast along the same path as the previous
storm. Good chances of showers and thunderstorms will continue
through Sunday night. Severe storms will be a good possibility
east of the effective frontal boundary on Sunday. The other
concern will be heavy rainfall and some flooding issues.
Stormtotal QPF will generally range from 3-4" from Thursday
night through Sunday night. Flooding concerns would generally
grow through the period, maximizing as the second system passes
Sunday.

Temperatures will be well above normal over the weekend, and
then cool down to more seasonable values early next week, as we
try to dry out.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1218 AM CDT Wed Apr 24 2024

A secondary cold front will move south through the area prior to
daybreak, turning winds more north-northeast at 9-12 kt. Within
this slight enhancement of cold advection, scattered 2-3 kft
clouds will at least get close to DBQ and MLI through 14Z or
so, with confidence fairly high that any broken cigs at that
level will be temporary. Northeast winds will gradually east
through the afternoon and veer to light easterly this evening.

&&

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

&&

$$

SHORT TERM...PAH
LONG TERM...PAH
AVIATION...Friedlein