458
FXUS63 KIWX 112359
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
759 PM EDT Tue Jun 11 2024

.KEY MESSAGES...

- Heating up in the coming days; highs in the mid 80s Wednesday,
  then upper 80s to low 90s Thursday.

- The next chance for rain and storms arrives 4 to 10 PM EDT Thursday.
  Isolated strong to severe storms are possible, with the main
  threat being damaging wind gusts.

- Highs will be in the low to mid 90s with heat indices upwards
  of 100 to 105 degrees starting on Father`s Day through at
  least the middle of next week! Can`t rule out a few low
  chances (20% or less) for showers and storms but this
  timeframe looks mainly dry.

&&

.UPDATE...
Issued at 749 PM EDT Tue Jun 11 2024

A weak lead short wave across southern Lake MI vicinity will
allow for mid level cloud deck to spread eastward this evening.
A band of radar returns is noted in association with this
feature, but sub-cloud layer is quite dry and would think at
most, a few sprinkles are possible across the west-northwest
over next few hours. Water vapor imagery does depict a stronger
upper level short wave across southern Wisconsin that will shift
across the southern Great Lakes overnight. Some better
moistening in 850mb-800mb layer should occur after 06Z tonight
across the west, which could be enough weak elevated instability
for a few showers overnight across the far west. Confidence in
isolated showers is low however, as less than optimal mid level
lapse rates may not allow much elevated instability to be
realized. May add just some slight chance PoPs overnight across
the west, but otherwise no major changes to previous forecast at
this time.

&&

.DISCUSSION...
Issued at 319 PM EDT Tue Jun 11 2024

Hope you enjoyed the cool mornings and seasonable daytime
temperatures the past few days! We are unlikely to experience any
more cooler than normal days in the upcoming weeks as summer takes
hold! With several dry days, ample mixing today has led to
temperatures climbing 30 to 35 above where they were in the low to
mid 40s this morning for lows! Northerly winds have kept seasonable
temperatures around today, but this will not be in the case for the
rest of the week. Winds will shift on Wednesday to become
southwesterly, and ample WAA will result in highs that will be in
the mid 80s to low 90s Wednesday and Thursday. High pressure builds
across the Ohio River Valley that will keep dry conditions around
until later in the day Thursday.

The main focus of the week aside from the approaching heat will be
the return of rain and storms chances Thursday afternoon and
evening. Severe weather is possible Thursday, with SPC putting the
north and west portions of our area in a Marginal Risk (level 1 of
5) for severe weather. Highs near 90 degrees and dewpoints in the
low to mid 60s will yield an increasingly unstable environment
during the day Thursday. As an area of low pressure lifts northward
through Ontario, the attendant cold front will sweep southeast
through our area Thursday evening. Isolated to scattered
thunderstorm development is possible out ahead of the front; a few
storms may be strong to severe. Long range and mid range model
guidance is starting to come into agreement, however, there are
still some discontinuities in timing and the amount of
forcing/instability present; GFS and NAM soundings depict
MLCAPE of ~1000 J/kg by Thursday afternoon with around 40 kts of
0-6 km shear orthogonal to the southeastward moving frontal
boundary. In addition, GFS soundings show DCAPE of ~800 J/kg,
which would promote a favorable environment for isolated
damaging wind gusts to occur. The best timeframe for a few
severe storms will be from 4-10 PM EDT Thursday. Storms should
die off as diurnal heating is lost Thursday evening. We will
continue to monitor this chance for severe weather so check back
for updates in the coming days!

Hot and humid weather is on its way! Surface high pressure and
impressive upper level ridging will build across much of the eastern
CONUS this weekend, setting the stage for a `heat dome` to set up.
Highs will be in the low to mid 90s with heat indices pushing 100 to
105 degrees starting on Father`s Day through at least the middle of
next week! Overnight lows in the upper 60s to mid 70s will offer
little to no relief from the heat. This is the typical summertime
"Ring of Fire" pattern for the Upper Midwest and Great Lakes regions
where any clusters of storms that do develop tend to ride around the
periphery of the heat dome. For now, the Sunday to next Wednesday
timeframe appears mainly dry, with only a few low chances (20% or
less) for rain/storms). For those who enjoy the hot, humid
conditions of summer, you won`t have to wait too much longer!

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 749 PM EDT Tue Jun 11 2024

Lead short wave will bring a potential of a few sprinkles at
KSBN through 02Z, but maintenance of a dry sub-cloud layer
should prevent any measurable precip. A stronger upper level
wave is evident on water vapor imagery across southern
Wisconsin, and a narrow axis of better low level moisture just
upstream of this trough axis could promote the possibility of an
isolated shower across northern Indiana overnight. Will keep
TAFs dry as confidence in isolated showers is very low due to
lack of appreciable elevated instability. An expansive ridge of
high pressure will shift off to the east overnight, setting up a
period of south-southwest winds at terminals into Wednesday
afternoon.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

UPDATE...Marsili
DISCUSSION...Johnson
AVIATION...Marsili