702
FXUS63 KILX 092357
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
657 PM CDT Sun Jun 9 2024

.KEY MESSAGES...

- Breezy northwest winds with gusts up to 30 mph north of I-70
  could lead to blowing dust in open areas into early evening.

- Comfortable temperatures will persist through Tuesday night
  before things turn very warm and more humid Wednesday through
  early next week.

- Next best chance of thunderstorms is Thursday night, with 20-40%
  chance from I-70 north. Slight chance of severe storms Thu
  evening over the IL river valley north of I-72.

&&

.DISCUSSION...
Issued at 315 PM CDT Sun Jun 9 2024

Mid afternoon surface map shows 1027 mb high pressure over central
Saskatchewan and riding southward across the Central Plains. Cold
front had pushed into the southern TN river valley and into
central AR. Radar mosaic shows convection was generally south of
I-64 in southern IL into central/sw KY, southeast MO and into
northern parts of AR/TN. Cirrus shield was along and south of a
Flora to Robinson line and retreating southward. Scattered cumulus
clouds were over northern CWA with high bases above 7k ft. Breezy
NW winds gusting to around 30 mph over central IL. Temps were in
the upper 70s and lower 80s, with mildest temps from I-57 west and
coolest temps in cloudier areas from Clay, Richland and Lawrence
counties south. Much drier air advecting into central IL with
dewpoints ranging from upper 30s and lower 40s from Lacon and
Pontiac north to the mid 50s along and south of highway 50 in
southeast IL.

Latest CAMs shows a short wave trof shifting southward across the
Great Lakes tonight. Diurnally driven cumulus clouds north of
I-72 to dissipate at sundown as breezy NW winds diminish and turn
north by overnight. Though a band of scattered to broken
stratocumulus clouds over WI to move southward over central IL
overnight ahead of trof. Lows tonight in the mid 50s, with some
upper 50s from highway 50 south. Monday will be the coolest day of
this week with strong upper level trof over the central and
eastern Great Lakes and Ohio river valley and into New England.
Scattered to broken stratocumulus clouds to decrease from nw to se
during the day Monday. High Monday in the low to mid 70s which is
about 10 degrees cooler than normal. Weak high pressure around
1018 mb to drift over IL Monday night and bring a fair/cool light
with light winds. Lows Monday night in the upper 40s to around
50F.

Pleasant day expected Tuesday with weak upper level ridging over
IL and surface high pressure ridge nearby. A weather system moving
eastward over the upper MS river valley on Tue to bring some
increase clouds over northern CWA especially from I-74 north while
its convection to stay nw of CWA on Tue. Highs Tue in the upper
70s to near 80F with fairly light winds becoming sw. Dry
conditions continue Tue night with lows in the lower 60s from
I-55 west and mid 50s in southeast IL.

A flat mid/upper level ridging building over the central and
southern Rockies and into the central and southern Plains during
mid week to bring much warmer temperatures into central/se IL Wed
and on. Highs Wed in the mid to upper 80s, warmest from I-55 west.
Humidity levels not too bad yet on Wed with dewpoints in the 50s
and lower 60s. Convection chances appears to stay nw of CWA Wed
through Thu morning over the Great Lakes and upper Midwest region.
A frontal system tracking south/se toward central IL Thu night to
bring 20-30% chance of thunderstorms by late Thu afternoon over
northern CWA and into much of central IL during Thu night. SPC has
slight risk of severe storms nw CWA Thu night especially during
Thu evening where instability and wind shear is forecast to be
greater. Hot on Thu with highs around 90F and more humid with
dewpoints in the 60s with sw breezes.

Weakening cold front presses se toward the Ohio river during
Friday with best chances of convection shifting se of central IL.
Still hot on Friday with highs in the upper 80s/lower 90s, warmest
in southeast IL. Then dry and slightly cooler and less humid Fri
night and Sat with strong upper level ridging building over the
mid MS and Ohio river valley as 500 mb heights rise to 588 meters
or higher. Breezy southerly winds return more summertime heat and
humidity next Sunday and Monday with highs 90 to 95F appearing
likely.

07

&&

.AVIATION...  (For the 00z TAFs through 00z Monday Evening)
Issued at 655 PM CDT Sun Jun 9 2024

Radiational warming continues to favor deep mixing this evening,
leading to overachieving northwest winds which are gusting upwards
of 20 to 25 kt. High resolution, short-term model guidance
continues to advertise these sharply dropping off with loss of
insolation between 00z and 02z Monday (i.e., 7 and 9 pm CDT Sunday).
However, another uptick in winds will occur with the arrival of a
weak frontal boundary tomorrow morning. Along this front, clouds
in the FL025 to FL050 range will overspread the region, with HREF
suggesting the highest chance (50-60%) for MVFR ceilings between
12-17z (7 am to noon) at BMI and CMI.

Bumgardner

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$