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000
FXUS63 KIND 170658
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
258 AM EDT Sat Jun 17 2023

.Short Term...(Today and tonight)
Issued at 258 AM EDT Sat Jun 17 2023

* A pleasant summer Saturday expected, although air quality may be a
  concern today.

Surface high pressure will be in control across the region today,
leading to mostly clear skies, light winds, and pleasant conditions,
with temperatures near normal.

Some lingering low level moisture will likely produce patchy light
fog near daybreak, primarily in the outlying areas. This fog will
mix out in typical diurnal fashion. Overall mixing will be modest at
best, although PBL depth will be fairly good, maxing out around 5-
6kft despite the overall weak flow. A few fair weather cumulus will
be possible during the afternoon hours, but skies should be mostly
clear.

A slight haze aloft may or may not be noticeable, as vertically
integrated smoke progs do show some lingering wildfire smoke in the
region, but near surface smoke should be minimal. Otherwise,
however, the light flow may produce some air quality issues, and our
IDEM partners have declared an Air Quality Action day for today. See
AQAIND and AQA products from our neighboring offices for details.

Blend temperatures are in the upper 70s to mid 80s this afternoon,
and this appears reasonable given the ample sunshine. Skies should
remain mostly clear much of tonight, and with dewpoints well down
into the 50s, see no reason why min temps shouldn`t get down into at
least the mid 50s as well. Lowered blend numbers a couple of degrees
as a result.

&&

.Long Term...(Sunday through Friday)
Issued at 258 AM EDT Sat Jun 17 2023

Currently, a broad split flow pattern prevails across the CONUS. A
potent zonal jet is located in the northern Pacific, entering
western North America south of Alaska before branching into distinct
northern and southern streams. Indiana finds itself within weak
ridging associated with the northern branch, while to our south the
more zonal southern branch skirts across the Gulf Coast. Much of the
active weather across the country has been concentrated along the
southern jet, with numerous severe weather outbreaks occurring from
Texas to Georgia.

A vort max riding along the southern stream looks to make its way
into the Ohio River Valley this weekend. Models have been trending
this feature slowly south and west, with dry conditions becoming
more likely through Sunday. Still, enough support among the models
exists to include chance PoPs across our southern counties. Precip
chances may linger into the new week, as guidance is honing in on
the idea that the system slows significantly as it passes nearby to
our south.

Simultaneously, ridging looks to build over the Great Plains before
extending northeastward. By mid week, the main axis of ridging will
be to our north over the Great Lakes. With the increasingly cut off
low to our south...what resembles a Rex Block may be taking shape.
As of right now, the cut off low is modeled to be far enough south
that precip chances dwindle by mid week. With a greater influence
from the ridging our weather may be largely quiet with near to above-
average temperatures. Occasional wildfire smoke may be present
throughout the long range, as numerous fires continue to burn in
multiple Canadian Provinces. Smoke may lead to periods of hazy
skies, red sunrises / sunsets, and some reduction in visibility and
air quality.

Beyond the long range period, there is some hints in guidance that
the ridge may retreat westward a bit...placing us within a
northwesterly flow regime. Should this pattern come to fruition,
then the potential for active weather may finally return to the
region. Given the complicated flow pattern and potential
blocking...confidence this far out is very low.

&&

.Aviation...(06Z TAF Issuance)
Issued at 117 AM EDT Sat Jun 17 2023

Impacts:

* Brief MVFR fog possible near daybreak at the outlying sites.

Discussion:

Surface high pressure will be in control across the region through
the period, leading to mostly clear skies and light and frequently
variable winds.

The weak surface flow combined with lingering low level moisture
should produce some MVFR fog near daybreak, primarily at the
outlying sites, although cannot entirely rule out brief visibility
restrictions at IND as well. Will continue with a TEMPO group for
those outlying sites and monitor IND progression through the night.

Any fog will mix out in typical diurnal fashion, with only a few
fair weather cumulus expected during the day Saturday.

&&

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

&&

$$

Short Term...Nield
Long Term...Eckhoff
Aviation...Nield