536
FXUS63 KIND 081641
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1141 AM EST Fri Nov 8 2024

.KEY MESSAGES...

- Above normal temperatures likely continuing through the forecast
  period, but near normal temperatures could return late next week.

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

&&

.FORECAST UPDATE...
Issued at 909 AM EST Fri Nov 8 2024

13z obs are indicating improvement on the visibility over pretty
much all the ob sites across central Indiana. This along with
another hour of full sunshine, beneath a broad surface ridge and
upstream of an approaching upper ridge, will result in any localized
fog lifting by or before 14z. GOES IR satellite loop and Hi-Res
soundings suggest high clouds will increase this afternoon, mainly
over the southwestern half of the forecast area. There should be
plenty of adiabatic heating to allow temperatures to reach slightly
above normal readings in the lower to middle 60s, close to
the DESI grand ensemble 90th percentile 2m temperatures, however.

&&

.SHORT TERM (Today and tonight)...
Issued at 300 AM EST Fri Nov 8 2024

Early This Morning...

High pressure continues to provide clear skies and light winds
across central Indiana early this morning. These conditions have
allowed patchy fog to develop, with visibilities bouncing around as
the fog drifts by.

Given little change in conditions through sunrise, would expect
patchy to areas of fog to persist. Will continue to monitor closely,
and will issue a Special Weather Statement is lower visibility
becomes more persistent.

Today...

Upper ridging will build across the area today while an upper low
moves out of the southwestern portion of the country. At the
surface, high pressure will remain in control.

High and perhaps some mid cloud will drift into the area today,
especially southwest. There will still be enough sunshine to bring
temperatures up to around 60 into the lower 60s.

Tonight...

Quiet weather will continue with the surface high and upper ridging
still influencing central Indiana. The center of the high will be to
the northeast, and some passing high clouds will move across. Thus,
ideal radiational cooling conditions will not be seen. However, feel
that blended guidance is still a bit warm. Will trim lows back a
bit, with readings in the middle 30s to lower 40s expected.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 300 AM EST Fri Nov 8 2024

The long term period looks to remain somewhat active with multiple
chances for rain. Dry conditions are expected at the start of the
period as surface high pressure remains the dominant weather feature
on Saturday across central Indiana.

By Saturday evening, surface high pressure shifts towards the
Northeast with a deepening low pressure system and associated cold
front moving into the region. Increasing dynamics combined with
anomalous moisture return from the gulf will likely support
widespread beneficial rainfall Saturday night into Sunday. The
heaviest precipitation from the system should fall over the mid-
south where the deeper moisture/stronger forcing is expected. That
being said, most areas could see around 0.5-1 inch of rainfall.
Locally higher amounts cannot be ruled out over the southern half of
central Indiana. Model guidance shows weak instability (less than
500J/KG) during this period suggesting there is a low chance for a
few thunderstorms.

Expect surface high pressure to build in late Sunday once the
aforementioned system departs. This will allow dry conditions to
return. Look for cooler temperatures early next week due to cold air
advection on the backside of the departing low, but temperatures are
likely to remain above normal due to relatively weak thermal
advection.

Model guidance shows another system approaching the region by the
middle of next week. Ensembles show a large spread in the location
of where the surface low develops, but both the ECMWF and GFS show a
moderate chance for measurable precipitation. More specific details
such as expected rainfall amounts should become clearer over the
coming days once models are in better agreement. While some
uncertainty exists this far out, there is good agreement in the
models that a more significant cooldown is likely behind the system.
This may finally help return temperatures to near normal.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1141 AM EST Fri Nov 8 2024

Impacts:

- Low chance of fog overnight with the best chance at KLAF after
  09z

Discussion:

A slightly tighter low pressure gradient and increase in high clouds
tonight should lessen the chance of fog.

Winds will veer from northwest to northeast and finally east through
Saturday as a low pressure system approaches from the west. Upper
ridging and a dry lower column should keep the showers away until
closer to Saturday night.

&&

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

$$

UPDATE...MK
SHORT TERM...50
LONG TERM...Melo
AVIATION...MK