Area Forecast Discussion
Issued by NWS Indianapolis, IN

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337
FXUS63 KIND 220207
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1007 PM EDT Mon Aug 21 2017

.UPDATE...
The NEAR TERM Section has been updated below.

&&

.SYNOPSIS...
Issued at 303 PM EDT Mon Aug 21 2017

Active weather will continue into Tuesday night as a frontal
system approaches and moves through the area keeping chances for
thunderstorms in the forecast. After the passage of the cold
front, temperatures will drop to below normal for a bit and dry
weather can be expected from mid week into the weekend.

&&

.NEAR TERM /Tonight/...

Issued at 1001 PM EDT Mon Aug 21 2017

No major changes. Few sprinkles left Bedford to Seymour and will
be gone before midnight.

Storm clusters near Peoria and St Louis may affect Terre Haute to
Kokomo after midnight while main thrust of showers and storms back
in Iowa and Missouri likely to arrive in western counties near
daybreak and central sections by end of morning commute.

With dewpoints near or in the lower 70s temperatures not to fall
much further.

&&

.SHORT TERM /Tuesday through Thursday/...

Issued at 303 PM EDT Mon Aug 21 2017

A cold front will approach the area on Tuesday afternoon. A bit of
variability in the exact timing, but looks like the front will
arrive on the northwestern border around 18z and be through the area
by around 0z Tuesday evening, give or take a few hours.
Thunderstorms should generate ahead of the front. Instability will
increase ahead of the front through the day and with forcing from
the front and increasing winds at 850 mb could see some
organization to the storms during the afternoon/early evening
hours ahead of/along the cold front. Thus potential for a few
strong to severe storms exists, with the best chances across the
southern and eastern portions of the forecast area. Moderate
confidence in solid coverage of thunderstorms sometime during the
day Tuesday, but timing is lower confidence with more model
variability there.

By Tuesday night the cold front will be reaching the border if its
not already through the area, and thus kept a chance for showers
and storms in the southeast counties but tapered to dry in the
northwest. Cooler high pressure will build in from the northwest
on Wednesday and settle in for the rest of the short term.
Slightly cooler than normal and dry conditions will be the rule
midweek.

&&

.LONG TERM /Thursday Night through Monday/...
Issued at 240 PM EDT Mon Aug 21 2017

Dry and pleasant weather through the weekend as the Great Lakes
and Ohio Valley reside under a broad upper trough and strong high
pressure at the surface. Dry flow from the north then east will
maintain highs ranging from the mid 70s to lower 80s through
much of the period. Nights will have a distinct autumn feel with
temperatures dropping as low as the lower 50s...maybe even upper
40s...Thursday and Friday night in some spots.

Heights aloft will recover with the upper trough shifting off to
the east by late weekend. The region will remain under the
influence of a surface ridge...but low level flow will transition
to southerly on the back side of the high...enabling Gulf moisture
to be drawn north into the region. Potential for a few showers and
storms by Monday and have introduced low pops.

&&

.AVIATION /Discussion for 220000z TAFs/...

Issued at 631 PM EDT Mon Aug 21 2017

VFR through the period with winds below 10 knots except gusty in
storms.

Currently dry with cirrus and a few remaining cumulus at sites.

High resolution models suggest thunderstorms could reach KLAF as
early as 220400z but more likely to be after 220600z. KIND and
KHUF should see return of thunderstorms by 220700z-0800z. Periods
of thunderstorms will then continue until frontal passage early
afternoon Tuesday by or after 221800z.


&&

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

$$

SYNOPSIS...CP
NEAR TERM...Tucek
SHORT TERM...CP
LONG TERM....Ryan
AVIATION...Tucek



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