174
FXUS63 KDVN 291646 CCA
AFDDVN

Area Forecast Discussion...CORRECTED
National Weather Service Quad Cities IA IL
1146 AM CDT Sat Jun 29 2024

...Updated for 18z Aviation and Hydrology...

.KEY MESSAGES...

- After a brief period of quiet weather this weekend, an active
  pattern sets up once again next week, with plenty of chances
  for showers and storms. Heavy rain is possible, but it is too
  soon to determine the severe threat.

- Moderate to Major flooding is expected on several area rivers.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 227 AM CDT Sat Jun 29 2024

Today, the system that brought widespread rainfall to the area will
move out. Aside from some residual showers on the back end of the
system, we are expecting dry conditions for the remainder of the
day. Overall, zonal flow will dominate, becoming more northwesterly
tonight and tomorrow. This will allow for surface high pressure to
move into the area tonight and into tomorrow. With this pattern in
place, we will remain quiet through the short term forecast.
Northwest flow will allow for cold advection to kick in, mainly
tonight and tomorrow, where clear skies and lighter winds tonight
will allow for us to cool off a bit. Daytime temperatures today will
be in the low-mid 80s for most, with the nighttime temperatures
dropping into the 50s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 227 AM CDT Sat Jun 29 2024

Sunday into Monday, high pressure will dominate the area,
bringing below normal temperatures to the area. Current guidance
brings widespread mid-upper 70s throughout the area. Aside from
an increase in clouds on Monday, this will be a beautiful and
dry stretch of weather. The increase in clouds will be a result
of the moisture return needed ahead of the next system, which is
expected to bring showers/storms to the area.

Monday night and into Tuesday, we see our first wave that is set to
impact the area this coming week. Much of the action with this seems
to be late Monday night, moreso during Tuesday morning, as the LLJ
takes much of the night to shift east over our area. This action
will be associated with the leading shortwave trough, with the bulk
of the energy in our northern forecast area. Thus, this will be the
focus for higher precipitation amounts and thunderstorm
potential. Latest trends have been showing that showers/storms
may continue into the daytime hours, with some dry time in the
mix. There remains some uncertainty on this, but will continue
to update accordingly. It is too soon to discuss deterministic
amounts of rainfall, but we will see the potential for heavy
rain. Guidance continues to highlight the potential for high
moisture content once again, with PWATs near 2.00-2.50".
Ensemble guidance remains low on rainfall probabilities on the
first round of precipitation, with and increase to 40-60%
chances for at least an inch of rain with the second round on
Tuesday night into Wednesday, as the larger wave passes through.
This increase in precipitation will result from the increase in
moisture seen, as the highest moisture content is expected on
Tuesday into Wednesday. Localized areas of higher rainfall will
be possible, especially where storms are seen.

Beyond that, guidance starts to diverge on the next system, with
large differences in timing and placement. While guidance seems to
favor the Thursday night into Friday timeframe for more
precipitation, will opt to refrain from any more details, as there
is plenty of time for this to change. In either case, it would seem
that we will approach the end of the work week with multiple rounds
of showers and storms for the area. All guidance highlights much of
the end of the week and into the weekend as an active period for
rainfall. Unfortunately, all of this rainfall will lead to further
fluctuations on the projected flooding along area rivers. Be sure to
stay up to date on local flood headlines!

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1143 AM CDT Sat Jun 29 2024

VFR conditions are expected through the TAF period. There is a
low chance (20-30%) for a brief MVFR ceiling at KMLI, KBRL at
the beginning of the TAF period with abundant low level moisture
lingering ahead of a cold front. Another low chance for a brief
MVFR ceiling will re-focus back north at both KCID and KDBQ
toward late afternoon into early evening associated with cold
air advection, ahead of an upper trough and secondary cold
front. Winds may back to the SW for a brief time early in the
TAF period ahead of a secondary cold front, but overall look to
be predominantly from the W/NW around 10-15 kts and become gusty
to 20-25 kts before dropping off later this evening/overnight.
Northerly winds are expected Sunday at around 10-15 kts.

&&

.HYDROLOGY...
Issued at 1143 AM CDT Sat Jun 29 2024

No significant changes for the tributary rivers from this
morning`s new forecasts. The crest on the Cedar River has gone
through Cedar Rapids and should reach Conesville by Monday
morning. The Iowa River forecast has come in a little lower, but
minor flooding is still forecast at Wapello and Oakville. The
Rock River continues to fall and have just cancelled the flood
warning at Joslin.

On the mainstem Mississippi, the new forecasts have resulted in
flood category changes for Dubuque, Camanche, and Le Claire LD14
to Major flood and Keokuk LD19 and Gregory Landing to Moderate
flood. Overall, rises are still expected through the next 7 days
and beyond for most sites. Broad crests are beginning to show
up in the last day of the forecast for Dubuque LD11 downstream
to Bellevue LD12. However, with additional rain expected Monday
night through Tuesday, these crests may be delayed or change
depending on where the rain falls.

&&

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

&&

$$

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