921
FXUS63 KIWX 220730
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
330 AM EDT Sun Sep 22 2024

.KEY MESSAGES...

- Showers and a few thunderstorms arrive from west to east after
  sunrise. Rain tapers off tonight.

- Hot again this afternoon in northwest Ohio, while those toward
  the Lake will be in the 70s.

- Additional rain arrives Monday night through Tuesday.

&&

.DISCUSSION...
Issued at 323 AM EDT Sun Sep 22 2024

Retreating high pressure has left behind dew points in the mid-to-
upper 50s early this morning. This is some 10 degrees drier than
dew points over western and central Illinois. Thus, approaching
rain will have dry air to overcome and POPs have been delayed by
a few hours. Time-height cross sections show a stout dry air
wedge in the lowest 25k ft, which diminishes by the afternoon
(Fort Wayne) with the arrival of improved forcing in the low-
levels as a cold front a low pressure center moves through.
Thunder cannot be ruled out, especially in the afternoon with
improved instability. Rainfall through Sunday night favors
Michiana south toward Logansport and Monticello, where rainfall
may exceed 0.50". Elsewhere, rainfall will be closer to 0.25".
One more note for today: high temperatures will vary from west
(near 75) to east (near 85 in northwest Ohio).

A break in the rain on Monday as the cold front departs, leaving
behind seasonable high temperatures in the low-to-mid 70s. Amid
broad troughing over the Central US and a ridge over the Gulf Coast,
the next shortwave ripples through Monday night and Tuesday. This
favors the highest rainfall totals for central and southern Indiana,
but a majority of our forecast area should at least see some rain
from this system as well.

The late-week forecast is murky, but with some agreement beginning to
show with respect to 500mb high anomalies. An anomalously
strong ridge is forecast to spread over the Great Lakes late
this week while a low takes shape over the southern US. This
setup could bring some Atlantic or Gulf moisture into our area
paired with above- normal temperatures. The in-house blend
appeared overly wet during that time period, so POPs were
limited to slight chance (15%) with some inkling that the next
forecast run could be dry late-week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 130 AM EDT Sun Sep 22 2024

Deteriorating aviation conditions expected later today as
midlevel trough and associated cold front cross the region. MVFR
ceilings are assured with IFR likely Monday night in postfrontal
CAA. Exact timing remains uncertain though with adjustments of a
few hours in either direction possible. Also uncertain is
potential for thunder. Can`t rule out an isolated storm but
instability is very meager with moist adiabatic lapse rates
through the column. Given timing uncertainties as well, will
hold off on any mention for now.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory from 9 PM this evening to 5 PM EDT Monday
     for LMZ043-046.

&&

$$

DISCUSSION...Brown
AVIATION...AGD