273
FXUS63 KIWX 260915
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
515 AM EDT Wed Jun 26 2024

.KEY MESSAGES...

- Isolated showers and thunderstorms developing this morning
  will become more numerous and focus across Central and NE
  IN/NW OH/SE Lower MI) by mid to late afternoon, then progress
  southward out of the region by this evening. Highs will be
  around 80 degrees, and lows in the upper 50s.

- Dry conditions prevail from tonight into late Friday
  afternoon and evening. Highs will be in the upper 70s and low
  to mid 80s.

- The next chance for showers and thunderstorms will be Friday
  afternoon and evening into Saturday night. Temperatures will
  be in the 70s and 80s.

&&

.DISCUSSION...
Issued at 514 AM EDT Wed Jun 26 2024

Another day another uncertain pop forecast with limited forcing to
kick precipitation off beyond the crossing cold front late this
morning/afternoon. We had a couple of isolated showers overnight,
however largely it`s been much drier than expected. Naturally given
the poor model performance (minus the HRRR who had mostly dry
tonight) I`m hesitant to have the likely/categorical pops this
afternoon-but with ambient moisture around, a cold front moving
through, and expected instability around 500-1500 J/kg (ML Cape-
particularly along/south of US 24)-felt the higher pops were
warranted after 15z. Models have a whole pot-pourri of solutions to
choose from, but kept close to the HRRR based on its performance
overnight to now. Did blend in with the RAP/NAM to bump things up a
bit around 15z-18z as later runs of the HRRR came in indicating at
least isolated development by 15z and increasing from there as the
front shifts southeast and becomes better focused. Wouldn`t be
surprised to see a couple stronger storms produce microbursts if we
can get better afternoon instability (some of the models have up to
500-1200 J/kg)--but at this point we are not in an SPC outlook and
my confidence is extremely low given model disagreements. Light and
somewhat variable winds will become somewhat breezy and shift W-NW
behind the front this afternoon. Highs today will be in the upper
70s and low 80s. Dry conditions and clearing skies return tonight,
with lows falling into the upper 50s and low 60s.

Mid level ridging and surface high pressure will build in behind the
exiting cold front tonight, effectively putting an end to any
precipitation chances through early Friday afternoon. Light winds
out of the N-NW tonight will shift to the E-SE by Friday and
increase to around 10 to 20 mph ahead of the next system. Highs will
be in the upper 70s and low to mid 80s.

By Friday afternoon a cut off low in the mid levels will begin its
eastward drift from Saskatchewan, digging slightly across the
northern plains and Canadian Prairies through Saturday night when it
reaches James Bay/Ontario. The associated surface low will drift
into the Dakotas Friday morning, with the warm front extending
southeast from there through MO/IA/AR and into LA/AL. This warm
front will lift northward through the day as the surface low
occludes, with the triple point reaching the area around Ludington,
MI by Saturday morning. So on Friday afternoon into the overnight
we`ll see an uptick in moisture from the gulf thanks to return flow
around high pressure centered over the Atlantic. The warm front will
lift northeastward through the CWA by Saturday morning, bringing
chances for showers and thunderstorms. The cold front at that point
is on our western doorstep, extending from Ludington, MI southwest
through Lake MI and into IL/MO/OK/KS. This will cross our forecast
area through Sunday morning/early afternoon (depending on model),
providing additional chances. With the front approaching around the
12z time frame Saturday and continuing eastward through the
afternoon and late evening hours, we have MUCAPE values around 1-3K
J/kg and decent surface instability, limited bulk 0-6 km shear of 30-
40 knots, and mid level lapse rates of 6-7C/km, we could see a few
stronger storms-but confidence is low at this point.

High temperatures will be in the 70s and 80s. Being in the warm
sector Saturday will bring the warmest temperatures, with highs
in mid to upper 80s. It will be coolest Sunday behind the cold
front with highs in the low to mid 70s.


&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1238 AM EDT Wed Jun 26 2024

Clouds are streaming in off a decaying complex of
thunderstorms moving through central IL. Showers are noted
upstream over Wisconsin, drifting southeast, in the vicinity of
a cold front there. This cold front will move through the TAF
sites later today. Forecast soundings depict an ample
environment for thunderstorms, but not nearly as robust as the
storms less than 24 hours ago. Confidence is medium for the
timing and there is some guidance that misses KSBN all
together; low confidence on that solution.

Ceiling trends will need to be monitored at KSBN early this
morning with FEW036 in the 0354z observation. However, upstream
observations are generally VFR and the in-house blend suggests
only a 30% chance of MVFR ceilings early this morning.

 &&

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

&&

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

&&

$$

DISCUSSION...MCD
AVIATION...Brown