428
FXUS63 KDVN 150555
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1255 AM CDT Sat Jun 15 2024

.KEY MESSAGES...

- A quiet start to the weekend, with overall dry conditions and
  seasonal temperatures

- Chances of showers and a few storms are possible Saturday night
  and Sunday morning, mainly for our northwestern areas

- Hot conditions expected for Sunday through Tuesday before some
  relief from the heat comes by mid-week

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 213 PM CDT Fri Jun 14 2024

The weekend starts off on a quiet note in our region as an area of
high pressure builds across the western Great Lakes. Upper-level
ridging will build across the upper Midwest Saturday, translating
eastward with time. A mid-level shortwave will ride the apex of the
ridge and translate across areas to our northwest. The general
consensus among the high-resolution model soundings indicate plenty
of dry air in place, which suggests dry conditions will prevail
through the daylight hours Saturday. The shortwave will at least
result in partly to mostly cloudy skies Saturday, with highs in the
lower 80s north to the middle 80s south. Also, expect some breezy
southeast winds, with gusts around 20 to 25 mph.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 213 PM CDT Fri Jun 14 2024

The long-term forecast period starts off on a bit more of an active
start, with chances of showers and storms (20 to 50% chances per the
NBM ensemble), mainly for areas north of Highway 30 and west of the
Mississippi River. A secondary mid-level shortwave trough will
translate across our northwestern areas, but the bulk of the large-
scale forcing for ascent will be north of our region. An attendant
southwesterly 40 to 50 knot nocturnal low-level jet will aid in the
forcing for our area. The question remains on the amount of
available moisture to support precipitation, and there is quite a
bit of spread among the high-res guidance on the spatial coverage of
any showers/storms. We are not expecting any strong to severe storms
with this activity at this time, given the location of the strongest
convergence from the LLJ and fairly modest deep-layer shear.
However, most-unstable CAPE values on the order of 500 to 1500 J/kg
will provide some fuel for any convection that does develop, which
will be more elevated in nature.

Once any lingering showers/storms taper off Sunday morning,
attention quickly turns to building heat and humidity for Sunday
through Tuesday. The overall synoptic pattern will support this,
with the jet stream lifting northward and a large upper-level high
pressure system building over the southeastern CONUS. Prolonged
southerly flow around the large area of high pressure will support
enhanced theta-e advection into our region, increasing temperatures
and dew points. 850 mb temperature anomalies are quite impressive,
with values around 3 to 6 degrees F above average, with the ECMWF
ensemble mean indicating even higher values than the GEFS ensemble
mean. The greatest temperature anomalies still appear to be over the
northeastern CONUS near the eastern Great Lakes. The ECMWF EFI
values for high temperatures Monday have increased to around 0.7 to
0.8 for Monday, which indicates a fairly strong signal for warmer
than usual temperatures. The latest NBM high temperatures for Sunday
through Tuesday are in the lower to middle 90s across the area, with
heat indices in the upper 90s to near 100 degrees! However, these
values are around the 80th percentile of the model spectrum, so the
NBM might be a tad on the warm side. Additionally, analysis of the
combined GEFS, EPS, and ENS ensembles indicate a dew point
temperature spread between the 25th and 75th percentiles of these
ensembles to be 5 to 8 degrees F, so there remains some uncertainty
on just how hot and humid we will get. In the end, confidence
remains high for some of the hottest conditions we`ve experienced so
far this year, with a 90+ percent chance of high temperatures Sunday
and Monday of 90 degrees or warmer per the NBM probabilities, so the
heat is coming! Although record highs are likely a stretch with this
upcoming warmth, we are more likely to tie or break record warm low
temperatures Monday and again Tuesday. Please see the Climate
section below for a list of the records that are in play to be
tied or broken!

By mid-week, the pattern will change to bring in a few mid-level
impulses over our area, which will help modulate temperatures a bit
by Wednesday and Thursday and also bring in increasing chances of
showers and storms. Exact timing is a bit more uncertain this far
out, but confidence is a bit higher that it will bring some relief
to the heat.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1244 AM CDT Sat Jun 15 2024

VFR to prevail through the period with light winds overnight,
increasing out of the SSE on Saturday to 10-20 kts. There is a
slight chance for isolated showers and storms mainly near CID
and DBQ through the day on Saturday into Saturday night.
However, confidence is too low on direct impacts at the
terminals to mention thunder in the TAFs with this update.

&&

.CLIMATE...
Issued at 213 PM CDT Fri Jun 14 2024

Record High Temperatures:

June 16:
KMLI: 98/1918

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

June 18:
KBRL: 97/1953


Record High Minimum Temperatures:

June 16:
KBRL: 75/1922
KCID: 76/1922
KDBQ: 74/1918
KMLI: 77/1918

June 17:
KBRL: 75/2018
KCID: 76/1897
KDBQ: 74/1921
KMLI: 78/2018

June 18:
KBRL: 76/2018
KCID: 74/2012
KDBQ: 74/1921
KMLI: 77/2018

June 19:
KBRL: 76/1953
KCID: 77/1953
KDBQ: 76/1931
KMLI: 78/1953

June 20:
KBRL: 76/1997
KDBQ: 74/1923

&&

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

&&

$$

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