Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 241344
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
944 AM EDT WED AUG 24 2016

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

&&

.SYNOPSIS...
Issued at 325 AM EDT Wed Aug 24 2016

A closed upper low will continue its track across southern
Saskatchewan and Manitoba, while a surface low and associated cold
front enter the Mississippi Valley. These features will be the
leading contributors to weather across Central Indiana through the
end of the week. First though, a weak wave ahead of the
aforementioned surface low will track across Wisconsin today,
triggering the first round of showers and thunderstorms across
Central Indiana early this morning. Further enhancement will be
provided as a cold front tracks across the forecast area tomorrow,
resulting in showers and thunderstorms into Friday morning. After
that, a brief lull in activity will commence on Friday afternoon
through Saturday morning. But, another upper trough will push into
the Upper Midwest late Saturday, bringing yet another round of
showers and thunderstorms to Central Indiana into next week.

&&

.NEAR TERM /Rest of Today/...
Issued at 944 AM EDT Wed Aug 24 2016

Area of showers and thunderstorms across Illinois continues to
evolve with northern areas weakening and the storms over central
Illinois strengthening. Have upped PoPs to likely this morning
across the far northwest to account for the stronger convection in
central Illinois.

Later today evolution of the convection is a bit murkier as the
storms move into less favorable air initially but with instability
increasing again during the afternoon. Short term hi res models are
still playing catch-up with current storms so confidence in their
solutions is low. Thus left afternoon forecast alone and will modify
when trends become clearer.

Lowered high temperatures a bit northwest given better chances for
convection this morning. Otherwise left them alone for now.

Previous discussion follows...

The main focus of the near term period will be shower and
thunderstorm chances as a shortwave enters Wisconsin.

Current radar mosaic is showing some sporadic showers and isolated
thunderstorms upstream across Iowa and Illinois. This activity
should start filtering into western portions of the forecast area
around daybreak, spreading eastward throughout the morning.
Thunderstorm chances will increase by late morning/early afternoon
with best forcing across the northwestern quadrant of the forecast
area due to enhancement from both 300 and 850 mb jets. As a
result, most of the area is under a Marginal risk for severe
weather.

High temperatures will soar into the mid to upper 80s, further
enhancing instability across the area this afternoon.  Generally
stuck close to a model blend for today`s highs.

&&

.SHORT TERM /Tonight through Friday Night/...

Issued at 325 AM EDT Wed Aug 24 2016

Thunderstorm potential will become further enhanced across the
northwestern counties tonight and tomorrow morning as low level
jet increases just ahead of approaching cold front. As a result,
will go with likely pops across the northern counties for tonight.
Meanwhile, SPC keeps the northern half of Central Indiana under a
Marginal risk for severe weather once again for Thursday as
aforementioned cold front passes through the area providing
forcing.

Showers and thunderstorms will linger across the southern counties
into Friday morning, but the remainder of Central Indiana will be
dry by then as high pressure strengthens at the surface across the
Midwest.

Temps through the period will climb into the upper 80s/low 90s
tomorrow with decent warm advection ahead of cold front. However,
temps will take a dip on Friday in the wake of the cold front,
falling back into the low to mid 80s. Meanwhile, overnight lows
will generally be in the 60s and 70s.

&&

.LONG TERM (Saturday through Tuesday)...
Issued at 322 AM EDT Wed Aug 24 2016

A stagnant late summer pattern will be the rule as models keep a
strong upper ridge of high pressure across the middle atlantic
states...eastern Kentucky and Tennessee.  They weaken it some
towards day 7.  Models also move an upper trough from the
upper midwest early on across the great lakes.

On the surface...high pressure over the eastern great lakes early
Saturday will move on to the east and a weak frontal system will
meander across our region much of the long term before drifting
to the south by late Tuesday.

Blended models give 20-30 percent POPS most of the long term period
with the exception of Saturday which should start out dry at...least
over eastern and central sections.  Temperatures will be slightly
above normal Sunday and Monday and near normal rest of the period.
Generally stayed close to model initialized temperatures.

&&

.AVIATION /Discussion for 241200Z TAF Issuance/...
Issued at 712 AM EDT Wed Aug 24 2016

Brief MVFR conditions possible this morning and in scattered convection
throughout the period...otherwise VFR expected.

Weather depiction indicates areas of 25 hundred ceilings across central
indiana even though in most areas this lower deck is scattered. Will
go tempo 25 hundred broken some areas this morning.

Area of showers and thunderstorms over northern/central Illinois will
reach western Indiana by 14Z and KIND and KBMG TAF`s midday. Could see
a period of tempo thunderstorms. Otherwise...will carry mainly VCTS rest
of the period.  Some models indicate there could be another round overnight
...but convection may lessen late.

Anyways...model soundings indicate mostly VFR ceilings through the period
with some MVFR fog at outlying TAF sites late tonight.

South or southwest winds will increase to 10 to 12 knots by midday and
become southwest around 5 knots tonight.

&&

.IND Watches/Warnings/Advisories...
NONE.
&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...JH



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