158
FXUS63 KIWX 121011
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
611 AM EDT Wed Jun 12 2024

.KEY MESSAGES...

- Chances severe storms late Thursday & Thursday evening with
  strong gusty winds and large hail.

- Hot & humid Sunday through Wednesday; highs around 90 to 95 with
  afternoon heat indices 95 to possibly as high as 105.

- After Thursday, best chances for storms are Monday and
  Tuesday late afternoons and evenings.

&&

.DISCUSSION...
Issued at 255 AM EDT Wed Jun 12 2024

Day 2 of return flow around a large surface high will continue
to allow temperatures to recover and reach well above normal by
Thursday with afternoon temperatures approaching 90. Deeper,
more significant moisture will be lacking and will help keep
heat indices from climbing much above 90 degrees.

The arrival of a weak cold front and associated upper level
disturbance and upper level jet support will bring a fairly
good potential for severe thunderstorms late Thursday into
Thursday. In addition to these parameters, the edge of a robust
EML will reach northern Indiana. Some capping with this EML
will likely delay storm development. At this point, believe the
best chances for storms are basically 20Z to 04Z (4pm EDT to
midnight), but best chances appear to be in a smaller 7pm to
11pm window. SPC has upgraded the marginal risk to a slight risk
over about the northwest half of the forecast area where the
best chances for storms will reside.

Otherwise, hot conditions will develop Sunday and very likely
persist into at least Wednesday. A low level moisture intrusion
will be delayed until Monday. Raised model blend dew points
about 2F bringing given this intrusion bringing heat indices
close to 100 during Monday and Tuesday afternoon. Given high
confidence in this scenario, will continue to message the heat &
humidity in the Hazardous Weather Product and social media.
Substantial precipitable water values of generally 1.8 to 2.1"
with high CAPEs will support chances for stronger storms with
heavy rainfall. Activity should be highly diurnal with the best
chances for storms during late afternoons and evening hours.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 610 AM EDT Wed Jun 12 2024

Ridging moving eastward out of the area with zonal flow aloft
into the region with southerly winds at the surface with a few
gusts around 15 knots possible through 00z Thur. Otherwise, VFR
conditions will prevail through the forecast period.

&&

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

&&

$$

DISCUSSION...Skipper
AVIATION...Andersen