647
FXUS63 KDVN 310452
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1152 PM CDT Thu May 30 2024

...Updated for 06z Aviation...

.KEY MESSAGES...

- Quiet and dry through much of Friday, with rain chances
  increasing Friday night into Saturday morning.

- Active pattern returns next week, with near-daily chances for
  showers and storms. Threat for severe weather remains low at
  the moment.

- Temperatures remain above normal, with long term guidance
  trending below normal by the end of next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 209 PM CDT Thu May 30 2024

Shortwave has ejected off of the Rockies this morning, with this
wave and associated energy slowly shifting east. This will help push
the upper ridge east of the Mississippi River Valley tonight and
through tomorrow. Ahead of this, winds will shift southeasterly
around H85 late tonight and into tomorrow morning, increasing
moisture throughout the area. Bulk of the shortwave energy remains
south of our area tomorrow, with stronger bouts of energy working
their way into the forecast area by late afternoon/evening
Friday. This will allow for precipitation chances to increase
into the evening, especially south of Interstate 80. Have opted
to push back precipitation onset though, as we will have a lot
of dry air to work through. Thus, the best chances for
precipitation will be Friday night. Little to no instability
will be seen, leaving us with mainly rain, aside from a few
isolated rumbles of thunder. With the best forcing in our south,
that will be where we see the highest rainfall amounts.
Although, the forecast remains less than an inch in those areas.
Currently, guidance favors areas along/south of a line from
Carthage to Princeton IL for 0.50-1.00" of rain, with the
remainder of the forecast area seeing 0.25" or less. Some
guidance is hinting at bringing slightly higher amounts north
and west, bringing between 0.25-0.50" roughly north to the Quad
Cities Area. Confidence is low on that at this time.

With gradually increasing moisture tonight, especially in the mid-
upper levels, we will see an increase in cloud cover. Thus, a mix of
moon and clouds will be seen, with temperatures in the low-mid 50s
for most. Tomorrow, we will warm up quite a bit again, but the
overall cloud cover may limit surface heating for some. Overall, we
are forecasting the mid-upper 70s, but will remain dry until the mid-
late PM hours.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 209 PM CDT Thu May 30 2024

As was mentioned above, rain will continue into Saturday morning,
especially for areas south of Interstate 80 and east of the
Mississippi River. After this passes, the remainder of the weekend
will be dry. Upper level flow will generally go zonal through Sunday
and the start of the work week. Although, weak impulses ahead
of a potent wave will shift the flow back to northwesterly by
the middle of next week. These impulses will bring periods of
showers and storms next week, with nearly daily chances for
precipitation. Temperatures will be unseasonably warm through
the middle of next week, with much of the area in the mid-upper
80s. Fortunately, overall moisture seems to remain low, which
should keep the humidity lower. While we will promote daily
chances for precipitation, this is not expected to be a wash-out
to start the week. Rather, sporadic chances of light-moderate
rain and storms. It is too soon to discuss severity, but will
continue to monitor for any chance.

Mid-late week, we see a bit of a pattern change. We see the upper
level flow shift strictly northwesterly again, owing to the deep
ridge building over the Rockies. This will lead to cooler
temperatures moving in, cooler than what we have seen over the last
couple of weeks. CPC currently favors near normal rainfall, with
temperatures below normal. Some guidance is more aggressive with the
cool air compared to others. This is generally due to the fact that
guidance still differs quite a bit on the overall pattern for next
week. Thus, will opt to refrain from too many details at this
time.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1150 PM CDT Thu May 30 2024

VFR conditions are expected to persist into this evening. Can`t
rule out a stray shower mainly west of CID to BRL this afternoon
with low to mid level theta-e advection, but SE flow advecting
dry air from Ohio Valley high pressure will keep this potential
too low for mention and preclude impacts. Tonight, shower chances
will further develop, especially south and west of DBQ to MLI
ahead of a mid level wave and strengthening isentropic ascent.
Conditions look to remain predominantly VFR tonight with a chance
(20-40%) for pockets of MVFR mainly for visibility in any stronger
showers. Winds will veer slightly from ESE to SSE on Friday while
becoming sustained around 10 kts with occasional gusts 12-19 kts
by afternoon, then back slightly to ESE and diminish to 5-10 kts
tonight.

&&

.HYDROLOGY...
Issued at 209 PM CDT Thu May 30 2024

No changes in flood categories on area rivers this morning.
Flooding continues on the Wapsipinicon, Iowa, Cedar, and lower
portions of the Mississippi River.

Major flooding will continue on the Wapsipinicon River near De
Witt until the middle of next week. The river will remain
between 13.1 and 13.3 feet through Monday. Additional rainfall
is forecast Friday night and again early next week, but model
trends have been lower with QPF through the next 7 days.
Significant changes to the river forecast is not expected in the
coming days.

The crest on the lower portion of the Iowa River is near
Oakville this morning. On the mainstem Mississippi, Minor
flooding will continue from New Boston LD 17 downstream to
Burlington and also at Gregory Landing. Crests will occur late
this weekend and early next week.

&&

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

&&

$$

SHORT TERM...Gunkel
LONG TERM...Gunkel
AVIATION...McClure
HYDROLOGY...Gross