000
FXUS63 KIND 071415
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1015 AM EDT Tue Jul 7 2020

.UPDATE...
Aviation section updated

&&

.SYNOPSIS...
Issued at 325 AM EDT Tue Jul 7 2020

Hot and humid conditions continue across central Indiana with weak
upper level ridging slowly breaking down over the next few days
ahead of an upper level low pressure system. Like the last several
days, isolated to scattered thunderstorms are expected today
through Thursday before more widespread rain moves in Friday and
Saturday. A brief break in the hot weather is expected this
weekend before reverting back to the hot and humid pattern early
next week.

&&

.NEAR TERM /This afternoon/...

Issued at 926 AM EDT Tue Jul 7 2020

Surface analysis late this morning shows broad but poorly
organized high pressure in place across Illinois and Indiana.
Skies were clear across the forecast area. The very warm and
humid air mass remained in place at the surface with light winds
and dew point temperatures in the lower 70s. Water vapor imagery
continues to show ridging in place across the American
southwest...steering the upper flow across the upper midwest and
Great Lakes. This was keeping stagnant flow aloft over Indiana.

A persistence type forecast will continue for this afternoon.
Given our warm and humid air mass will expect iso-sct showers and
thunderstorms to develop across the area. Convective temperatures
near 90 will be reached early this afternoon and with CAPE values
over 2400 J/KG and pwats over 1.5 inches...once again as we have
seen the past several days...TSRA`s will develop. Thus have
trended pop grids toward 30-40 percent pops across the area this
afternoon as peak heating is reached. Stuck close to persistence
on highs.

&&

.SHORT TERM /Tonight through Thursday Night/...

Issued at 325 AM EDT Tue Jul 7 2020

Any ongoing showers and thunderstorms will come to an end by the
early overnight hours. Depending on where and how widespread the
rain is today, a few areas of fog look possible tonight as skies
clear and winds drop to near 0. Still somewhat skeptical this
occurs but with a more moist column compared to the last few
nights, fog development is higher than in past nights where models
over forecasted the fog potential.

As we move into Wednesday, the persistent weather pattern of
upper level ridging and isolated to scattered afternoon
thunderstorms will continue before beginning to shift late
Thursday into Friday. This ridge will begin to break down during
the afternoon hours on Thursday ahead of an upper level low
pressure system that will bring more widespread rain and cooler
temperatures during the long term period. In the meantime,
diurnally driven thunderstorms are expected Wednesday and Thursday
with slightly higher chances on Thursday.

Highs will climb into the low to mid 90s Wednesday and Thursday.
Lows will fall into the low 70s through Thursday night.

&&

.LONG TERM /Friday through Monday/...
Issued at 322 AM EDT Tue Jul 7 2020

Models and ensembles agree the ridge will be more compact and over
the four corners area on Friday as a sharp upper trough and
associated cold front drop southeast across the Great Lakes and Ohio
Valley on Friday. The interaction of the trough and very warm, moist
and unstable air will result in widespread thunderstorms Friday with
lesser chances in its wake Friday night and Saturday. Will have to
keep an eye on storm potential on Friday afternoon as much more
impressive dynamics than recent times arrive.

After that, another trough will move through and bring more chances
for unsettled weather to the area Sunday and possibly Sunday evening
before and upper ridge brings dry weather to the area early next
week.

With the cold front to the south and east, prefer the more
seasonable blend as opposed to the warmer pre-frontal passage short
term temperatures. Look for afternoon highs mostly in the mid and
upper 80s through next Monday, although some locales could see 90
degrees on Friday.

&&

.AVIATION /Discussion for the 071500Z IND Taf Update/...

Mainly VFR Conditions are expected to continue this taf period.
No significant changes to the ongoings Taf`s. Afternoon convection
is expected and have used VCTS to account for this as confidence
is low for specific timing and locations. Any TSRA that strikes a
TAF site may produce brief MVFR conditions.

Previous Discussion Below

/Discussion for 07/12Z TAF Issuance/...

Issued at 619 AM EDT Tue Jul 7 2020

VFR outside of convection today, MVFR vsbys possible early
tomorrow.

Much of the day will be dry with isolated to scattered convection
during the afternoon hours. Confidence remains low on exact
coverage and timing for any TS. Winds will be light and variable
through the period with a diurnal cu field around 050. Patchy fog
looks possible tonight, but with models repeatedly being too
aggressive on fog formation, have low confidence at this time with
best chances at LAF and HUF.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...White
NEAR TERM...Puma
SHORT TERM...White
LONG TERM....MK
AVIATION...White