056
FXUS63 KIND 071036
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
536 AM EST Thu Nov 7 2024

.KEY MESSAGES...

- Cooler and mostly cloudy today before skies clear late

- Above normal temperatures to continue through the forecast period

- Rain and a few thunderstorms late Saturday into Sunday, with
  additional rain chances mid-week next week

&&

.SHORT TERM (Today and Tonight)...
Issued at 300 AM EST Thu Nov 7 2024

Stratus has settled back in across much of the forecast area early
this morning...evidenced nicely in current sounding data by the
presence of lingering moisture within the near surface layer beneath
a strengthening inversion. Isolated showers were near and just south
of the Ohio River currently and should remain south of the forecast
area through the morning. 07Z temperatures ranged from the lower 40s
over the northern Wabash Valley to the mid 50s south of I-70.

The ongoing cloud cover is the primary focus for the short term as
high pressure builds into the Ohio Valley from the north through
tonight and finally pushes the remnant frontal boundary over
Kentucky this morning further south.

There are breaks in the stratus deck and in particular over portions
of the forecast area north of I-70. That axis of clearing will drift
south over the next few hours and should enable a quick drop in
temperatures. Despite the remnant moisture in the near surface
layer...northerly winds holding at 5 to 10 mph will be sufficient to
limit fog concerns and keep any development localized through
daybreak. A broader area of stratus expanding south through northern
parts of the state will overspread the forecast area over the next
several hours and combine with the stratus already over the Ohio
Valley associated with the plume of moisture and remnant front to
our south. Expect an abundance of low stratus past daybreak and
through much of the morning.

Model soundings show the inversion remaining stubborn potentially
well into the afternoon as subsidence and drier mid level air
advects into the forecast area. Weakening wind flow through about
800mb will not help with cloud deck scattering either. This should
translate to lower clouds lingering as they transition to stratocu
from diurnal heating through the afternoon...then finally mixing out
towards sunset as drier air infiltrates the boundary layer. Have
held onto greater cloud coverage for a much longer part of today
based on above thoughts.

Clearing skies will come this evening as the broad high pressure to
our northwest expands east. Predominantly northerly winds will
lighten tonight but the presence of deeper subsidence into the
region should largely mitigate fog potential and keep any
development localized.

Temps...coolest day since Saturday expected today as weak cold
advection settles across central Indiana. Despite that though...low
level thermals support highs in the upper 50s and lower 60s which
would remain a few degrees above normal for early November. Lows
tonight will fall into the mid and upper 30s across most of the
forecast area.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 300 AM EST Thu Nov 7 2024

Friday through Sunday ...

A broad ridge of surface high pressure will provide pleasant,
peaceful and bright conditions across Wisconsin, Michigan, Ohio and
Pennsylvania to end the workweek.  Fair weather will also be the
rule for central Indiana, although clouds will thickening through
the early weekend ahead of an approaching stacked low...that is now
expected to track from the Texas Panhandle to the Upper Midwest by
Sunday.

Broad southeasterly flow into Indiana should bring better
precipitable water over 1.25 inches for 1-2 periods during the
middle of the weekend...although overall trends here are slightly
less impressive than previous runs...especially with what should be
a weakening Hurricane Rafael over the west-central Gulf unable to
provide much moisture into the subtropical flow that makes it across
the Ohio River.

Nevertheless expect scattered to numerous showers at times this
weekend, with greatest chances of light-moderate rainfall south of I-
70 which will have a longer duration of potentially steadier rain
rates.  Expect the occluded system to pull its cold front east
across region during the Sunday timeframe, bringing a return to dry
conditions as the weekend ends.  Unseasonably mild readings to
continue with mid-latitude jet retracted well to our north and
prolonged southerly winds.

Monday through Wednesday...

More of the same synoptic set-up will continue into the next
workweek.  Another pronounced, autumnal upper trough will plunge
into the western CONUS...while the broad ridge`s attempts to build
north through central North America are suppressed by a weaker short
wave crossing the north-central US...resulting in a dry quasi-zonal
flow into the Midwest.

The greatest forecast challenge will probably be sky cover and
perhaps winds...with various SCT/BKN decks crossing the local region
courtesy of both the weak disturbance and then a potential more
moist/robust south-southwesterly flow by the end of the period as
another broad gradient likely sets up ahead of deepening low
pressure over the central Plains.  H850 temperatures trending from
around 5 to 10 degrees Celsius will promote above normal readings
probably again reaching unseasonable to anomalous levels by the mid-
week.  The normal max/min at Indianapolis through the long term will
continue to fall from 55/37 to 53/36.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 536 AM EST Thu Nov 7 2024

Impacts:

- Stratocu lingering into the afternoon with periodic drops to MVFR
  ceilings this morning

- N/NE winds at 10kts or less through the period

Discussion:

Most of the earlier stratus deck has shifted into southern Indiana
with an area of mainly clear skies. Broader area of stratus with
ceilings around 3kft dropping south into the region and will
overspread the terminals throughout the morning. May see brief drops
to around 2500ft at times over the next few hours but does not
appear that we will see widespread MVFR ceilings develop.

Low clouds will lift and mix out into the afternoon but model
soundings suggest that it may take until late day to begin fully
scattering the stratocu as the low level inversion finally weakens
and deeper subsidence advects into the region from the north. As
high pressure fully takes over by this evening skies will become
mostly clear for tonight. Winds will remain from the north through
much of the forecast period at 10kts or less.

&&

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

&&

$$

SHORT TERM...Ryan
LONG TERM...AGM
AVIATION...Ryan