132
FXUS63 KIND 230524
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1224 AM EST Sat Nov 23 2024

.KEY MESSAGES...

- Light rain showers ending over eastern counties this evening
- Clouds linger into Saturday before diminishing
- Warming trend this weekend with a chance of light rain Monday
- Lower than normal forecast confidence the second half of next week
  with some wintry precipitation potential

&&

.FORECAST UPDATE...
Issued at 958 PM EST Fri Nov 22 2024

Cloudy and cool will continue to be the rule overnight as central
Indiana sits under the western portions of a very deep cut-off low
as it slow departs the eastern CONUS.  Despite mid-level ridging,
already arriving from the Upper Midwest...low stratus will continue
to stay locked in under a strong inversion over the 850-800 mb layer
through at least Saturday morning.  Slight visibility reductions are
possible at times from patchy mist tonight, with no impacts
expected.  Breezy west-northwesterly surface flow tonight will
precede the upcoming transition back to brighter and milder
weather...with sustained winds slowly diminishing to under 10KT by
pre-dawn hours. Widespread readings in the lower 40s will drop
slightly over the next 9 hours...with dewpoints in the upper 30s to
around 40F guiding tonight`s lows.

&&

.SHORT TERM (This evening through Saturday)...
Issued at 252 PM EST Fri Nov 22 2024

Rest of the Afternoon and Tonight...

The stratus deck has remained entrenched across central Indiana,
this afternoon, per GOES-16 visible satellite loop, with the
clearing line all the way west across western Iowa and southwest
Missouri, closer to the surface high pressure ridge. Otherwise,
radar was showing a lake effect rain showers in the cyclonic flow on
the back side of the east coast surface low. Gusty northwest winds
and an upstream surface ridge across the Plains and Great Lakes has
provided warm advection allowing temperatures to bounce back to the
lower 40s over much of central Indiana.

Surface high pressure will work its way toward southwestern Indiana
overnight. This and a drying boundary layer could allow for a few
breaks in the overcast toward daybreak over southwestern sections.
Otherwise, the clouds should remain thick, and the lake-effect rain
showers should end shortly after sunset as they settle eastward with
backing boundary layer flow. The insolation from the thick cloud
cover should keep temperatures from falling to freezing.

Saturday...

Surface high pressure will build in across central Indiana Saturday.
Hi-Res soundings also are indicating good boundary layer drying
which is expected to lead to gradual clearing from southwest to
northeast. The breaks in the clouds and winds shifting to the west
will allow temperatures to top out from around 45 to 50 degrees or
near normal.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 252 PM EST Fri Nov 22 2024

Dry and mild conditions will continue through the second half of the
weekend as ridging aloft expands into the Ohio Valley before
transitioning to a fast quasi-zonal regime for much of next week.
Systems will quickly move along within the flow aloft bringing
chances for precip at times next week with the continued possibility
for a larger and more impactful storm by late in the period with
potential amplification in the upper levels over the eastern U S.

Saturday Night through Sunday

Dry conditions will continue Saturday night and Sunday as surface
flow transitions to a southerly direction. Skies will gradually
clear Saturday night into Sunday before increasing again late day as
a frontal boundary approaches from the west. Highs Saturday will
largely hold in the 40s with the stratus limiting warming. With the
onset of warm advection for Sunday though...will see a return to
above normal readings mainly in the mid and upper 50s.

Sunday Night through Tuesday Night

The aforementioned cold front will sweep across the region on Monday
with rain developing. Showers will arrive as early as Slate Sunday
night across the Wabash Valley but the bulk of the widespread rain
will come on Monday afternoon along the front and as stronger flow
at 850mb translates across the Ohio Valley. Rainfall amounts will
generally be a quarter inch or less with rain ending Monday evening
as high pressure builds in. High temperatures will be mild ahead of
the front on Monday...running from the mid 50s to around 60.

Dry weather returns for Tuesday as the high tracks across the Great
Lakes and Ohio Valley. A more robust signal for subsidence in the
wake of the front should lead to stratus diminishing quickly Monday
night. Despite the return of sunshine on Tuesday...gusty northwest
winds and cold advection will make for a chillier day as highs
remain in the low and mid 40s.

Wednesday through Friday

A surface low is set to eject out into the southern Plains Tuesday
night and Wednesday and track east along a quasi-stationary boundary
extending into the Tennessee and lower Ohio Valleys. Confidence
continues to increase in precipitation returning by Wednesday and
persisting through late week but low confidence exists within the
details at this early stage. It appears central Indiana will be on
the colder north side of the frontal boundary and displaced from the
deepest moisture focused closer to the boundary over the Tennessee
Valley. The presence of a colder airmass north of the boundary could
potentially present precip type challenges at times as well...
especially at night as temperatures near or go below freezing. Highs
both Wednesday and Thursday are likely to range from the upper 30s
to mid 40s...then shift colder Friday.

Extended guidance continues to hint at a broader piece of energy
aloft coming southeast late next week which would support the idea
of a more amplified upper level pattern developing with an
intensifying surface wave somewhere over the region. At this early
stage...expect increased chances for precipitation throughout the
second half of next week with impacts to travel possible. Will
continue to fine tune details over the next several days.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1224 AM EST Sat Nov 23 2024

Impacts:

- IFR/MVFR ceilings overnight...MVFR Saturday improving to VFR late
- MVFR visibility possible this evening in BR/DZ
- Light flow Saturday to back mainly during afternoon hours to SW

Discussion:

GOES16 continues to show extensive cloud cover across Central
Indiana and the Region. Moisture within the lower levels remains
trapped under an inversion over central Indiana into at least early
afternoon Saturday.  IFR and Low-MVFR ceilings to be the rule.
MVFR visibility in patchy DZ/BR is still possible but should
not be widespread.

As warm air advection and southwesterly flow resumes on Saturday
afternoon. This heating and mixing should bring about and end to the
MVFR/IFR Cigs. Forecast soundings and Time heights at that time show
a loss of saturation within the lower levels.

Low confidence on the possible return of MVFR/IFR conditions
overnight/early Sunday with radiational cooling.

&&

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

$$

UPDATE...AGM
SHORT TERM...MK
LONG TERM...Ryan
AVIATION...Puma