025
FXUS63 KIWX 101636
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1235 PM EDT Fri May 10 2024

.KEY MESSAGES...

-Dry today and Sunday, with variable cloud cover. Highs in the 60s
today, and the 70s on Sunday.

-Chances for showers and thunderstorms tonight and Saturday. Severe
weather is not expected. Lows tonight will be around 50 degrees, and
highs Saturday will be in the 50s and low 60s north of US 24, and
the mid to upper 50s south.

-Chances for rain for much of the week ahead. Thunderstorms are
 possible at times, but severe weather is not expected. High
 temperatures will be in the 60s and 70s.

&&

.DISCUSSION...
Issued at 514 AM EDT Fri May 10 2024

At long last, a glorious dry day is upon us! As of this writing, the
last of the precipitation just exited the southern CWA. A ridge of
high pressure builds in aloft ahead of the next system through the
afternoon, drifting slowly eastward with time. Light winds and
mostly sunny skies with high pressure centered over the central
plains arching up into IN/IL/OH. Highs will be in the low to mid 60s
with light north-northwest winds.

Chances for showers and thunderstorms return this evening into
Saturday as an upper level low settles in over the Great Lakes
region. The corresponding surface low will drift into Lake Superior
by 6z tonight, then by Saturday evening, drop into southern Lake
Huron and Lake Erie. We may see some weak showers with increasing
WAA tonight ahead of the warm front (some models suggest as early as
21z but I held pops until after 00z given lower confidence). As the
low continues its southeastward progression, it begins to occlude
and we see the cold front move through much of the forecast area by
12z Saturday, and east of it by the afternoon. Focused rain chances
with the cold front passage tonight, and kept chances into Saturday
afternoon as there is a trough that lingers in the far east behind
the exiting low/cold front, and I think this could trigger continued
chances for showers and storms. Overnight we have decent mid level
lapse rates--around 6.5 to 7 C/km with that wave, in addition to
strong synoptic forcing with the sharper trough.  MUCAPE values grow
to around 800 J/kg through 15z Saturday, with surface based values
of 100-400 J/kg. Think we have enough with the weak moisture
advection at the surface (dewpoints in the low 50s) ahead of the low
to warrant likely/cat pops along the front, and to add at least
chances for thunder. 0 to 6 km bulk effective shear along/ahead of
front looks to be around 35 to 55 knots (with the mid level jet
streak in Chicago around 60-75 knots that sinks southwest of our our
CWA through the morning), but given limited instability don`t
think we`ll see any strong to severe storms. Lows drop to around
50 degrees tonight. Highs on Saturday will be in the 50s and
60s, with blustery NW winds and decreasing cloud cover from west
to east.

Dry conditions return on Sunday (and possibly into Monday) as
another high pressure ridge builds in overhead with a surface high
below. Temperatures will warm into the mid 70s west half, and low
70s east as we warm advect ahead of the next system. A cold front
stemming from low pressure over James Bay will reach Lake Michigan
late Sunday night, then attempt to cross our CWA through the day but
washes out or gets hung up. This sets the stage for Tuesday-
Thursday`s weather as another system from the central plains lifts
in (upper level low included!) and brings intermittent rain and
storm chances to our cwa again. Confidence in exact locations for
best precipitation chances is low at this far out, so left consensus
pops for now and confined thunder to best times of instability.
Temperatures Monday into Friday will be in the 60s and 70s.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1235 PM EDT Fri May 10 2024

Primarily VFR this period ahead of sys dropping out of the upper
midwest. Cold front will support a narrow band of light rain
overnight but of limited duration as sys aloft is quite progressive.
Otherwise brief/transient post frontal stratocu may develop toward
daybreak however model implied signal is muted w/fairly robust
mixing in shallow cold advection wing. This will yield a quick jump
in w-nwrly gusts to 25kts at times by mid morning.

&&

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

&&

$$

DISCUSSION...MCD
AVIATION...T