352
FXUS63 KIND 200906
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
506 AM EDT Sun Apr 20 2025

.KEY MESSAGES...

- Showers and a few thunderstorms overnight into Monday morning

- Brisk conditions Monday...trending to lighter breezes and warm
  springlike weather Tuesday-Wednesday

- Rain chances return Thursday-Saturday amid continued above normal
  temperatures

&&

.SHORT TERM (Today and tonight)...
Issued at 300 AM EDT Sun Apr 20 2025

Synoptic Pattern...

H20 vapor imagery was showing an upper low, across eastern New
Mexico, embedded in a Rockies trough. This feature will pivot
northeast to the Kansas City area late today and northern Wisconsin
by Monday morning. Fast southwest flow around the base of the trough
will bring the stationary front, currently near the Ohio River,
northward across central Indiana today. Meanwhile, an associated
surface low will lift north out of northern Texas into northeastern
Missouri late today and into southeastern Wisconsin by Monday
morning. A triple point will move from west central Illinois late
today to southwestern Lower Michigan Monday morning as a cold front
sweeps northeast across central Indiana overnight.

Today...

As the front, to our south, lifts north today, look for showers to
be increasing from southwest to northeast, after 09z. BY 18z, the
showers should be confined to northern sections and diminish in
coverage. BUFKIT Hi-Res soundings keep quite a bit of moisture
around in the 2-4K foot layer and cu development progs suggest
plenty of diurnal cu is expected but still should see a few breaks
in the overcast which should, along with the warm front moving
through and winds shifting to the southeast, should allow
temperatures to rebound nicely. That said, with the front only
expected to make it just north of the I-70 corridor, there will be a
large temperature gradient with highs from the upper 60s north to
around 80 southwest.

Tonight...

The synoptic lift and deepening moisture, courtesy of a 60 knot low
level jet, will result in widespread overnight showers. With
diminishing and already weak instability, would not rule out
thunderstorms as well and the deep shear suggests a few could be
strong but severe storm chances look low. Look for convective
coverage on the order of 80% or higher. The gusty south winds and
thick cloud cover will keep temperatures from falling too much,
ahead of the cold front, which should be somewhere near or east of
the I-69 corridor by daybreak. Lows in the lower to middle 60s
southeast and middle 50s northwest look good.

&&

.LONG TERM (Monday through Saturday)...
Issued at 303 AM EDT Sun Apr 20 2025

Monday through Wednesday...

The synoptic pattern will shift slightly northward leaving a weaker
upper gradient amid a zonal W/WSW flow over the Midwest...with 500mb
heights around 555-560 dm promoting a trend from seasonable to above
normal temperatures.  Can expect a few showers and a stray rumble of
thunder Monday morning as the departing system`s supporting short
wave lifts across the Great Lakes, dragging the southern portions of
its rather weak axis across Indiana.  Dry conditions are otherwise
expected through Wednesday with forcing retracted well to the north
and weak surface ridging holding local precipitable water values
mainly under 0.75 inches.

Expect robust gusts Monday under the belly of the passing upper
trough...although mainly WSW flow and decreasing clouds should still
allow highs in the 65-70F range.  Tuesday and Wednesday should
finally bring consecutive pleasant spring days under ample sunshine
and mainly lighter breezes from southerly directions.  Resultant
moderation will return 70s to most locations Tuesday and widespread
75-80F readings Wednesday.

Thursday through Saturday...

The remainder of the workweek will feature a return of Gulf moisture
and at least occasional precipitation chances courtesy of moderate
southerly to southwesterly flow.  Perhaps scattered showers Thursday
will trend to more numerous showers/t-storms around the Thursday
night to Friday night periods as a weaker short wave embedded in the
WSW mid-level flow tracks near or just northwest of central Indiana.
Surface low pressure, expected to strengthen slightly while tracking
NE into the Great Lakes may help guide timing and coverage of
precipitation.

Decent model agreement in a better organized cold front dragging
across at least most of the Midwest going into the Saturday
timeframe ahead of very broad and strong Canadian high pressure.
This may bare watching for potential excessive rainfall threat
should the boundary have a delayed passage...although at least
moderate confidence that better deep moisture is at least suppressed
to the Ohio Valley and south by the end of the long term.  Above
normal warmth expected through Friday should be set back to more
seasonable conditions for next weekend.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 506 AM EDT Sun Apr 20 2025

Impacts:

- MVFR and worse conditions through the period in precipitation
  but conditions will mostly be VFR

- There will be a few showers are this morning and convection
  including the potential for strong thunderstorms will return
  after 06z Monday

- LLWS possible after 03z Monday

- Winds

Discussion:

A stationary front, near the Ohio River, will return as a warm front
today as a low pressure system moves into the Plains. This will
allow winds to switch back to the southeast this afternoon and south
tonight. Meanwhile, a cold front will also approach the Wabash
Valley overnight. Increased instability, moisture and lift will
bring widespread showers and possibly a few strong thunderstorms to
the terminals toward the end of the TAF period. Flying conditions
will mostly be VFR but MVFR and worse at times in convection. LLWS
and south winds gusting to near 25 knots are also expected overnight.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...MK
LONG TERM...AGM
AVIATION...MK