095
FXUS63 KDVN 161930
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
230 PM CDT Sun Jun 16 2024

.KEY MESSAGES...

- A thunderstorm complex will continue to translate through the
  southern portions of the area this afternoon, which will
  support the continued threat for isolated strong to severe
  storms

- Hot and humid conditions will continue through Tuesday before
  some relative relief arrives for Wednesday

- Periodic chances of showers and storms remain with us for
  Wednesday through the end of the week

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 221 PM CDT Sun Jun 16 2024

We continue to keep an eye on a complex of showers and thunderstorms
that have developed over our southern forecast area early this
afternoon, caused by an MCV that developed over eastern Kansas early
this morning. Given the hot and humid conditions, characterized by
observed temperatures in the upper 80s to near 90 and dew
points in the upper 60s to lower 70s, SBCAPE values per the RAP
are progged around 2500 to 3500 J/kg, which is quite
substantial. The latest CAM guidance has the MCV convection
remaining along and south of I-80, but with a northeastward
track, points north of I-80 in northwest Illinois and far east-
central Iowa will be under the gun for strong to severe
convection over the next few hours. The main threat continues
to be locally strong wind gusts to around 60 mph, with large
hail and an isolated tornado being a secondary threat. SPC
continues to have most of the area in a Marginal Risk (level 1
of 5) for severe weather, with much of northwest Illinois in a
Slight Risk (level 2 of 5).

This afternoon, heat indices have increased to the middle to upper
90s, so the heat and humidity have arrived. Expect this to continue
Monday, and even into Tuesday (more on Tuesday in the long-term
forecast discussion). Monday still looks to be the hottest day of
this stretch of heat, with high temperatures in the middle to upper
90s, and heat indices in the middle/upper 90s, near 100 for
some isolated areas. We will have to watch closely for the
potential for Heat Advisory headlines as the latest guidance
indicates a period of at least 6 hours or more of 100+ degree
heat indices, mainly for our west-central Illinois/far
southeastern Iowa counties. Although the guidance has come into
better consensus on these values, there is still at least some
noticeable spread among the CAMs for dew point temperatures,
with a spread of around 2 to 5 degrees F between the 25th and
75th percentiles on the 16.12z HREF, so confidence is a bit
lower on how high the heat indices will reach. Regardless, it
will be a hot day all-around, so anyone that will be outdoors
for a period of time should take extra precautions to protect
themselves from the heat!

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 221 PM CDT Sun Jun 16 2024

Monday night through Tuesday night will remain quite warm for this
time of the year, with yet another day of high temperatures into the
lower to middle 90s and heat indices into the middle to upper 90s
for Tuesday. Overall, Tuesday`s heat appears to be similar to what
we are experiencing today, so heat headlines aren`t expected at this
time for Tuesday. As we`ve been mentioning, new record highs aren`t
expected with this stretch of heat, but we are more confident
for record warm low temperatures to be broken, especially for
tonight, Monday night, and Tuesday night. See the Climate
section below for the list of records that could be tied or
broken.

A pattern change is expected to occur by Wednesday, as the upper-
level ridging over the eastern US breaks down, and a longwave trough
develops over the Intermountain West region. As the trough
approaches, an attendant cold front will sweep through the area,
which will bring widespread chances (30 to 60%) of showers and
storms. This should bring at least some relative relief to the
heat and humidity, although high temperatures in the upper 80s
to lower 90s south of the Highway 20 corridor will remain
possible for Wednesday through Friday. A few additional mid-
level shortwaves are expected to overtop the ridge into our
area, so additional chances of precipitation will be in place
through the end of the week. Chances for strong to severe storms
remains low, which is evident in the CSU severe weather
probabilities indicating either very low probabilities or none
at all for this period.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1225 PM CDT Sun Jun 16 2024

Mostly VFR conditions are expected to continue for this TAF
period. We are tracking a cluster of showers and storms that is
currently moving through our southern areas early this
afternoon. MVFR, possibly IFR, ceilings and visibilities will
be possible with this cluster, which should impact the BRL and
MLI TAF terminals over the next few hours. There was measured
wind gusts to 40 knots at KMPZ with the leading thunderstorm,
with weaker winds elsewhere under the precipitation. We have
used TEMPO groups to highlight the most likely timing of this
activity. This cluster will continue to slowly move
northeastward this afternoon, moving out by late this afternoon.
Otherwise, gusty southerly winds will remain with us today,
weakening after sunset.

There is a low potential for low-level wind shear as the
nocturnal low-level jet returns. However, it isn`t expected to
be as strong compared to last night, so we have left out of TAFs
for now. CID and DBQ appear to be the most likely locations to
see any LLWS, if it develops at all.

&&

.CLIMATE...
Issued at 300 AM CDT Sun Jun 16 2024

Record High Temperatures:

June 17:
KBRL: 98/1944
KMLI: 98/1897


Record Warm Minimum Temperatures:

June 16:
KMLI: 77/1918

June 17:
KDBQ: 74/1921
KMLI: 78/2018

June 18:
KDBQ: 74/1921
KMLI: 77/2018

June 19:
KDBQ: 76/1931
KMLI: 78/1953

&&

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

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz/Uttech
AVIATION...Schultz
CLIMATE...Schultz/Uttech