153
FXUS63 KIWX 141739
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
139 PM EDT Sun Jul 14 2024

.KEY MESSAGES...

* There are periodic chances (30-60%) for showers and storms today
  through Tuesday night. Storms could be locally severe with
  damaging winds and flooding the primary threats during this
  timeframe.

* Hot and humid conditions are expected today and Monday, dependent
  on storm coverage and timing. Monday`s afternoon peak heat indices
  may near 100 degrees.

* Cooler, drier weather is anticipated Wednesday through this
  weekend.

&&

.DISCUSSION...
Issued at 326 AM EDT Sun Jul 14 2024

An unsettled pattern will linger through at least Tuesday with
numerous convectively aided disturbances tracking east-southeast
over an enhanced theta-e plume draped across the Upper Midwest and
western/southern Great Lakes. Periodically stormy and humid wx will
result with low confidence in daily high temps and convective
chances/intensity as guidance struggles to resolve mesoscale
features (composite outflows) and the low amplitude nature to
convectively modulated perturbations. The result is a forecast
littered by chance PoPs, SPC marginal to slight severe outlooks, and
high humidity.

For this morning, the first outflow dominant MCS is bring decaying
convection into the area. Wind gusts to 30 mph and locally heavy
rainfall remain possible immediately behind the leading sfc outflow.
Outflow stable bubble might put a lid on convection for much of the
day otherwise, though hard to remove PoPs as low level southwest
flow likely erodes MLCIN at some point with renewed scattered storms
possible along the trailing composite outflow boundary. Prospects
for another more organized outflow dominant MCS increases later
this evening into the early overnight.

The local area remains divorced from more favorable deep layer
shear to the northwest tonight through Monday night, with deeper
shear even trailing a stronger synoptic cold front by the
Tuesday/Tuesday evening periods. This would suggest more outflow
dominant convective clusters (isolated strong-severe convection
- wind primary threat) with the lacking shear and impressive
MUCAPE reservoir in the vicinity. With that said, more intense
MCS`s can produce a more intense wind field allowing for greater
shear/outflow balance, highest probs on occurrence Monday
night.

The high pwat airmass, and the potential for convective
outflows to slow or back build, also brings excessive rainfall
and flooding into the mix with any MCS, especially in nw IN and
sw MI given recent heavy rainfall from Beryl`s remnants. There
has been a consistent signal in model guidance for excessive
rainfall Monday night.

Monday still appears to be the best opportunity for near advisory
peak PM heat indices (100F). A more comfortable continental airmass
will provide relief from the active wx and humidity mid week through
next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 134 PM EDT Sun Jul 14 2024

Convective overturning in wake of current intense convection
moving through ern through cntrl IN will yield quiet wx near
term. However strong upstream destabilization underway across
cntrl/ern IA ewd through nrn IL ahead of robust MCV that arose
from overnight storms across the Dakotas. Expect renewed storm
develop in this area toward sunset and tracking e-sewd this
evening. Ewd extent owing to longevity and intensity/evolution
in time in doubt and left out attm invof KFWA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...Air Quality Alert until midnight EDT tonight for MIZ177-277.
MARINE...None.

&&

$$

DISCUSSION...Steinwedel
AVIATION...T