569
FXUS63 KDVN 170051
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
751 PM CDT Thu May 16 2024

.KEY MESSAGES...

- Fog appears to be a growing threat heading into the overnight
  hours.

- Highs temperatures warming into the 80s Friday through
  Monday.

- Depending on where a developing storm track lays out, it could
  be a potentially wet pattern across the region next week with
  several rounds of heavy rain possible.

&&

.Update...
Issued at 751 PM CDT Thu May 16 2024

Looking at radar and observations, the front which was supposed
to be moving southeast tonight, is actually become stationary,
and perhaps is lifting a bit north. Dewpoint temperatures
remain in the lower 60s over our southeast 1/2, and without dry
advection tonight, we are looking at a potential dense fog
event, beginning near the front, and settling southeast into
Illinois with time. For now, I`ve updated grids and the HWO, as
well as graphics, to include a more significant threat for dense
fog.


&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 209 PM CDT Thu May 16 2024

At 2 PM, scattered showers and isolated storms were located east
of a line from Ottumwa to The Quad Cities to Freeport Illinois.
A cold front sits along a line from Ottumwa to Fairfield to
Dubuque. Temperatures ranged from 71 degrees at Burlington to 77
degrees at Monticello with dewpoints in the upper 50s to lower
60s.

In the near term, a cold front will push to the east of the area
and into eastern Illinois by 00 UTC on Friday. The threat for
scattered showers and storms will continue ahead of the front
but will quickly come to an end by 00 UTC Friday. There may be
an uptick in thunderstorms late this afternoon and into this
evening. Think that the severe threat has been diminishing with
weak mid level lapse rates. Skies will clear from west to east
this evening with winds becoming light variable. This may lead
to the development of fog with some low level moisture in place
but confidence is low in this occurring.

On Friday, a 500 mb shortwave trough will pass to our south and
east through the day. Models have continued to trend southward
with chances of precipitation with 20 percent chance of showers
in the southern third of McDonough County. Expect partly sunny
skies south of Interstate 80 in northwest Illinois with mostly
sunny skies elsewhere. High temperatures will generally be in
the upper 70s to around 80 degrees.

&&

.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 209 PM CDT Thu May 16 2024

The Upper Midwest will remain under the influence of the northern
jet stream as trough swings across the northern Plains with
downstream ridging in place across the region. This is leading
to a drier forecast through the weekend with warmer
temperatures. High temperatures on Saturday and Sunday will be
in the lower to mid 80s with lows in the upper 50s to lower
60s.


Sunday night through the remainder of the period, the flow aloft
will transition to southwesterly flow as troughing in the northern
and southern streams phase. This will allow a series of embedded
shortwave energy to lift across the area and bring chances for
showers and storms each day.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 611 PM CDT Thu May 16 2024

Rain and thunderstorms have ended/moved east of all TAF sites
this evening, with a VFR evening in store for all locations. A
slow moving front will wash out over the area tonight, with
light winds in all locations after sunset. The remaining higher
dewpoint air near BRL will lead to potential morning fog. There
are chances 20-40% that this could be dense fog there in the 10z
to 14z window. We will watch that carefully this evening, for a
LIFR period to include in future forecasts. For now, will opt
for a temporary 1SM IFR period at BRL and a 3SM period at MLI.

&&

.HYDROLOGY...
Issued at 1051 AM CDT Thu May 16 2024

Changes: None.
Discussion...

Most tributary rivers in eastern Iowa have crested and are
slowly dropping. The exception is the lower Iowa River where the
crest is currently working its way through Wapello and Oakville.

On the Mississippi, Gladstone and Burlington will begin a broad
crest just above flood stage that will continue through Friday.

After a relatively dry weekend, the active weather pattern will
return next week with the potential for several rounds of rain.
While rainfall amounts continue to be somewhat uncertain, any
heavy rainfall would prolong the high river levels on tributary
rivers in eastern Iowa, northern Illinois and on the Mississippi
River.

The longer range outlook through the end of the month has a
40-42 percent probability of above normal rainfall. This outlook
suggests the potential for additional improvement with the
severe drought conditions across eastern Iowa. Unfortunately,
this outlook would also suggest that river levels could remain
higher than normal.

&&

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

&&

$$

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