764
FXUS63 KIND 111039
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
639 AM EDT Tue Mar 11 2025

.KEY MESSAGES...

- Sunny and warmer; Mostly Clear tonight

- Well above normal temperatures expected this week with breezy
  conditions at times

- At least low potential for heavy rain and minor flooding early
  next weekend along with very strong and gusty winds,
  particularly Saturday

- Potential for strong to severe storms Friday night into Saturday

&&

.SHORT TERM (Today and tonight)...
Issued at 321 AM EDT Tue Mar 11 2025

Synopsis:

Surface analysis early this morning shows a ridge of surface high
pressure stretching from eastern TX across the TN Valley to the
middle Atlantic states.  Low pressure was found over eastern Ontario
with a cold front stretching southwest across WI, IA and NB.  These
two systems were resulting in south to southwest flow across Central
Indiana. Aloft, zonal flow was in place from the Great Plains to the
Ohio Valley and water vapor imagery shows strong subsidence in place
across Indiana and points to the south and to the west. GOES16 shows
clear skies across the state.

Today and Tonight -

Another pleasant and warm day and mostly clear night is expected
across Central Indiana with above normal temperatures. Models today
and tonight keep the zonal flow in place aloft with little to no
forcing in place. Mid levels remain dry, showing subsidence and this
is also seen within the time heights and forecast soundings.  The
main weather feature today and tonight will be within the lower
levels. The previously mentioned cold front is expected to sag
southward across central Indiana this afternoon, and stall through
at least the overnight hours. This front has little cloud and
moisture with it and precipitation will not be expected. The main
result from it/s arrival may be a few more high clouds. Thus mostly
sunny today and mostly clear tonight will work just fine.

Warm air advection will remain in play today and tonight as 850mb
temperatures remain around 8-10C. South or Southwest flow is
expected for much of the day. Given this, highs at or slightly above
persistence, around 70, will be expected. Tonight/s lows will be
mainly in the 40s, but be warmer mainly south of stalled front.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 321 AM EDT Tue Mar 11 2025

Quiet and warm weather is expected for the most part from Wednesday
into Thursday night, the sole exception being very low chances for
an isolated shower or storm Thursday as a weakening upper low slides
eastward across Kentucky and Tennessee.

With the vast majority of forcing for ascent concentrated south of
the area, the primary contributor to precipitation chances in the
area would be any upright instability present, which even the more
bullish GFS shows as minimal, and mostly concentrated in the mid and
upper levels, with a fairly deep layer of neutral static stability
or even some convective inhibition to overcome between the LCL and
about 700 mb. Blend keeps some low PoPs in the far southwest in the
morning and southeast in the afternoon, and have tempered even these
low PoPs a bit. Strongly suspect the area will end up dry, as only
NBM 90th percentile and above have any measurable precipitation in
the forecast area.

Focus then shifts to the strong low pressure system poised to impact
the area late Friday into the weekend.

Initial impact of this system will be to quickly increase the
pressure gradient across the area, leading to gusty winds on Friday,
which should be a very warm day with plentiful sunshine and ample
mixing, producing highs in the mid to upper 70s and frequent
afternoon wind gusts of 25-35 MPH.

Friday night into early Saturday, precipitation associated with the
warm conveyor belt will push through the area. Despite unfavorable
diurnal timing, strong dynamics and solid MUCAPE values suggest
thunderstorms, some of which may be strong to severe, are a good
bet, driven in part by a 50-60KT low level jet. Though nocturnal
stabilization would typically tend to mitigate damaging wind
concerns, the strength of the overall flow coupled with low level
lapse rates remaining relatively steep suggest this may not be as
helpful as one might hope. Additionally, guidance tends to struggle
with easterly extent of nocturnal severe threats in this part of the
country, and experimental machine learning guidance is a bit more
aggressive at this point, which definitely keeps the threat top of
mind. A fast-moving overnight QLCS Friday night with at least some
severe threat persisting is certainly a plausible if not likely
scenario at this point.

In addition, heavy rain and localized flooding is at least a minor
concern, even with rapid storm motions, given precipitable water
values near climatological maximum for the time of year.

Finally, gradient winds even outside of convective activity may
remain fairly strong overnight and especially into Saturday given
the continued steep low level lapse rates and strong flow overall.
Gradient gusts overnight Friday night may remain near 30-35 MPH at
times, increasing during the day on Friday to 40-50 MPH, with
locally higher gusts not out of the question.

Models have shifted secondary cyclogenesis along the cold front to
our south, along with an associated heavy rain band late Saturday
into Saturday night back a bit further west, though still largely
south and east of the area - but this too will merit close
monitoring as the event draws closer.

A quick cooldown will follow late in the weekend, with temperatures
back nearer seasonal normals, though this will be brief, with highs
likely to return back into the 50s and 60s for Monday into Tuesday.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 638 AM EDT Tue Mar 11 2025

Impacts:

- Winds approaching 15KT at times

Discussion:

VFR conditions are expected throughout the period. Sustained winds
or perhaps a few gusts may approach 15KT at some sites through this
afternoon. A dry frontal boundary will sag into the area today,
causing wind shifts later in the day, especially at LAF.

No obstructions to visibility are expected through the period.

&&

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

&&

$$

SHORT TERM...Puma
LONG TERM...Nield
AVIATION...Nield