346
FXUS63 KIWX 091740
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
140 PM EDT Thu May 9 2024

.KEY MESSAGES...

-Rain with chances for thunderstorms today. There are low chances
for rain showers late tonight far west near Lake Michigan. Highs
will be in the mid to upper 50s and 60s, with breezy northeasterly
winds.

-Cool Friday and Saturday, with highs in the upper 50s and low to
mid 60s. There are chances for Showers and a few thunderstorms
Saturday, but otherwise expect partly to mostly sunny skies.

-Chances for showers and storms through the first portion of the
 work week. Highs will be in the 70s.

&&

.DISCUSSION...
Issued at 531 AM EDT Thu May 9 2024

As of this writing, a surface low  was centered just south of IND,
with an elongated trough extending back from the low into Minnesota.
Showers and thunderstorms are just to the east of this trough, with
mainly light showers extending eastward north of the low in our CWA.
The lightning thus far is further west of us in the better elevated
instability, however expect a downtrend (and southeastward movement)
into the afternoon as the low departs and the better
moisture/instability begin to wane. Increased moisture advection
thanks to the nose of a weak LLJ has led radar returns over our CWA
to blossom in the last hour or so, with quite a gradient in
dewpoints from NE to SW in our forecast area. Near White county, IN
we have dewpoints around 59 degrees. Near Hillsdale MI in the
northeastern CWA, dewpoints are around 42 degrees! Expect the best
rain to focus along this gradient, which will move slightly north
then sink south and east with time. SPC clipped our far south and
eastern CWA in the marginal risk for severe weather, but I`m
skeptical given we have limited instability and wind shear (less
than 30 knots of bulk effective shear and 500 J/kg of sfc based CAPE
to work with)...as the better moisture/instability/proximity to the
low will be just to the south of our CWA. Mid level lapse rates
don`t do much for us either-with our area seeing between 5-6.5C/km.
Left the thunder chances in the south and east through the day, but
wouldn`t be surprised if it remained fairly limited. Highs today
will only be in the 50s and low 60s, with mostly cloudy skies and
strengthening east-northeast flow into the afternoon.

We`ll see a lull in the precipitation this evening before additional
rain showers are possible tonight along a trough axis along Lake
Michigan, but probability is low given limited moisture. Dry
conditions prevail for Friday with an upper level ridge and surface
high in place, with highs in the 60s. Lows will be in the 40s both
tonight and Friday night.

A potent little shortwave will impact our area late Friday night
into Saturday night, with a corresponding surface low moving from WI
southeastward into our central/eastern CWA by Saturday morning, then
into Ohio by the evening. Rain is likely. Scattered to isolated
thunderstorms are possible too, with mid level lapse rates
around 6.5 to 8C/kg, decent moisture transport in the low/mid
levels, and around 500 J/kg of sfc based CAPE. Highs will be in
the 60s.

Sunday (possibly part of Monday) will be dry, with mostly sunny
skies and highs in the upper 60s, low to mid 70s (warmest west
half). It looks like we`ll see another upper low for the first part
of next week, so expect daily chances for showers and storms with
highs in the 70s.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 140 PM EDT Thu May 9 2024

Weak surface low is currently moving across the area. Precip has
temporarily ended at KSBN and will temporarily end at KFWA in
the next two hours as a midlevel dry slot moves overhead.
Ceilings are also expected to improve slightly though remain low
MVFR through the evening. Additional wraparound showers are
expected later this evening but ceilings will continue to slowly
rise as dry air advection and mixing increase slightly. Return
to VFR expected by late tonight with tranquil weather on Friday.

&&

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

&&

$$

DISCUSSION...MCD
AVIATION...AGD