612
FXUS63 KIWX 021727
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
127 PM EDT Thu May 2 2024

.KEY MESSAGES...

- Normal to above normal temperatures through the week, with
  highs in the 70s and 80s, cooler near Lake Michigan. Lows will
  be in the 50s and 60s.

- There are chances for showers and thunderstorms this week. A
  few strong to severe storms are possible late this afternoon
  into tonight, mainly northwest.

&&

.DISCUSSION...
Issued at 353 AM EDT Thu May 2 2024

Our forecast area lingers on the western periphery of an upper level
ridge through the entirety of the period, with various shortwaves
attempting to break it down as they progress eastward this week.
This brings a lot of uncertainty to the forecast, which features low
to mid range chances for showers and storms during at least a
portion of each day this week. Added the greatest detail today into
tonight, then went broader with pops beyond that, sticking close to
the consensus beyond Saturday. Highs this week will be in the 70s
and low 80s, with some locations (especially near Lake Michigan) in
the upper 60s at times. Lows will be in the 50s and 60s.

Otherwise, for today we have a marginal risk for strong-severe
storms in our northwest (hugging Lake MI), which is low confidence
for our area. Have only 20-25 percent pops in the west half through
2 pm EDT, then increasing from west to east at around 20-40 percent
from midday until late evening. A warm front will lift northward
into our forecast area through the day, and by the 21-00z time frame
tonight it`s draped from roughly Lake Michigan southeastward through
Fort Wayne into Lima, OH. Depending on the model, storms may or may
not develop along this front during the afternoon with warm
air/moisture advection (not too impressive on the moisture). Some of
the guidance, outside of a few morning showers, keeps us completely
dry until 00-03z-with instability building in the warm sector to
around 1500 J/kg. Towards the evening hours, the ridge begins to
erode thanks to forcing from the approaching shortwave. This would
probably be our best shot, if any, for severe weather, into the
overnight. Bulk effective shear is strongest north of the front,
with most of our area seeing less than 30 knots-so we`d be looking
at isolated severe at best. Mid level lapse-rates are also a paltry
5-6 C/km, and forcing is generally limited until the cold front
moves through late tonight into Friday. Overall in terms of the
severe weather ingredients, things seem a little disjointed.

The cold front moves through Friday, with chances for showers and
thunderstorms ahead of the front-but not too impressed as far as
stronger storms are concerned (a lot depends on how things go
today/tonight). Despite better forcing with the cold front, we still
have limited mid-level lapse rates and 300-700 j/kg sfc based cape
ahead of the front (Depending on the model).

A few weaker shortwaves move through this weekend, which will bring
us low chances for showers and storms, but confidence is not high so
kept capped around 20-45 percent (Focused along/south of US 24 by
Sunday). Otherwise the next best chance for showers and
thunderstorms will be Tuesday night into Wednesday morning as a much
stronger system lifts into the area.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 127 PM EDT Thu May 2 2024

A cold front will cross the area late tonight into early Friday
with rain showers likely. Some lightning is possible ahead of
the front (primarily at KSBN) but overall poor moisture/
instability will limit coverage and the VCTS could be pulled
entirely. A brief period of MVFR ceilings is anticipated behind
the front Fri morning but a return to VFR is expected by the
afternoon as rain exits west-east.

&&

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

&&

$$

DISCUSSION...MCD
AVIATION...AGD