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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KDVN 211313
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
813 AM CDT Sun Apr 21 2024

.KEY MESSAGES...

- Another possible freeze/frost night tonight before we warm
  back up.

- Active pattern into the week with additional rounds of rain
  and thunderstorms Monday into Tuesday and to end the week.

&&

.UPDATE...
-- Changed Discussion --
Issued at 812 AM CDT Sun Apr 21 2024

Area temperatures have climbed at or above freezing, and so the
Freeze Warning has been allowed to expire.
-- End Changed Discussion --

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 317 AM CDT Sun Apr 21 2024

It should be nicer today than yesterday as ridging builds into
the area leading to clear skies. NW flow will continue today,
however downsloping and warmer temperatures north of the area
will advect into the area leading to H85 temps above 0. With the
clear skies and deep mixing expect temperatures to reach into
the upper 50s to low 60s. Winds should be lighter than yesterday
but still noticeable with gusts 10-20 MPH.

Tonight, clear skies are expected. While have a warmer airmass
in place, dewpoint temps are expected to be near to below
freezing across the area. This should help temps drop off
tonight again. With winds dropping off after sunset, expect
frost and even some more freezing temperatures. It is likely
that we will need additional frost/freeze headlines again
tonight.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 317 AM CDT Sun Apr 21 2024

Shortwave is still forecast to move through the area Monday into
Tuesday. A leading wave may actually bring some showers to the
area before 00z Tuesday. CAMs that have solutions that far keep
the bulk of the precip before 00z Tuesday north of the area,
however the Hires-FV3 does have some showers I-80 and north
Monday afternoon. Looking at RH progs, it looks like the llvl
moisture doesn`t really make its way into the area until after
00z Tuesday. At this time, have not added pops for this chance,
later shifts will need to keep an eye on this. After 00z
Tuesday, chances for precip increase. Llvl forcing is weak with
this system so elevated Fgen seems to be producing most of the
precip. As the cold front moves south during the day on Tuesday,
it becomes slightly better defined across the southern CWA. This
may increase the shower potential. As earlier shifts noted,
there are strong winds in the low levels. CAPE is rather paltry,
however we could mix down some gusts with the showers,
especially with any showers near the cold front in the
afternoon. Most of the area will see light precip. NBM
probabilities for greater than 0.25 inches is only 30-50%.
Greater than 0.5 inches is 10-20%. This is an increase from the
day shift, however, I think that most of the area will see under
0.25 and more like a tenth of less due to the weaker forcing.
Better chances for accumulation are across the southern CWA.

Guidance continues to show the deep trof for the weekend. A
leading wave is still forecast to move into the area for Friday.
In fact, it is forecast to swing negative as it moves into the
area. SPC day 7 forecast yesterday had the area in a 15% chance
for severe weather. The CSU machine learning had a further
south severe weather threat area. I think what is clear is that
system will likely bring some severe weather to the central
CONUS on Friday. The exact placement of the better moisture
and warm sector is unknown. This unknown is the biggest key for
us to get strong to severe storms. We have 5 days until we get
to Friday, so a lot can change.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 533 AM CDT Sun Apr 21 2024

VFR conditions are expected through the period as clear skies
are expected. Winds will stay around or below 10 kts through the
period, decreasing to less than 5 kts tonight as the sun sets.
No sig wx impacts to aviation expected.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
IA...None.
IL...None.
MO...None.
-- End Changed Discussion --

&&

$$

UPDATE...McClure
SHORT TERM...Gibbs
LONG TERM...Gibbs
AVIATION...Gibbs