Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 230645
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
245 AM EDT Tue Jul 23 2019

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

&&

.SYNOPSIS...
Issued at 300 PM EDT Mon Jul 22 2019

Showers will end by early this evening as a cold front departs to
the south. High pressure will build in from the northern and
central Plains...bringing dry and pleasant weather for much of
this week. Temperatures will gradually warm by the weekend but
humidity levels will remain comfortable. The next chance for rain
and storms is not expected until early next week as a frontal
boundary approaches from the upper Midwest.

&&

.NEAR TERM /Rest of Tonight/...
Issued at 1018 PM EDT Mon Jul 22 2019

Forecast is in good shape. A mostly clear night with much cooler and
drier air is in store. Nudged down lows a but in the northwest with
the lowest dewpoints in that area, and made minor tweaks to temps
elsewhere.

Previous discussion follows...

Back edge of the showers are gradually shifting southeast this
afternoon with most rain now along and E/SE of Interstate 69. Clouds
lingered further north across the rest of the forecast area with the
clearing line approaching the northern Wabash Valley. Such a
difference with temperatures this afternoon compared to the last
several days with low to mid 70s over much of the area at 19Z.

Showers will continue to shift southeast through the rest of the
afternoon and should be entirely clear of the forecast area by early
evening. Bulk of the CAMs have a very good handle on this...and will
gradually lower chance pops across southeast half of the forecast
area over the next few hours. Little to no instability present and
will keep thunder out of the forecast.

Thick cloud shield over the region will also begin to shift
southeast into the evening as high pressure over the central and
northern Plains begins to exert its influence. Will see skies begin
to clear by early evening over the northwest half of the area with
clearing further south prior to midnight. Progressively drier air
advecting into the region overnight combined with northerly winds
remaining at 5-10mph will mitigate any substantial fog issues late
tonight into early Tuesday.

Temps...the lower dewpoints are lagging the cold front by a couple
hundred miles but values in the 50s are on the doorstep to central
Indiana now and will spread south through the entire forecast area
tonight. Lows falling into the mid to upper 50s will make for the
most comfortable night in quite a while. A model blend will work
well.

&&

.SHORT TERM /Tuesday through Thursday/...
Issued at 300 PM EDT Mon Jul 22 2019

Forecast challenges are few through the short term as the
aforementioned high pressure becomes the dominant influence across
the central portion of the country.

The ridge aloft which has persisted across the area for the last
several days will shift west into the Intermountain West as a strong
upper low tracks east from James Bay and carves out a trough over
the eastern part of the country. With expansive surface high
pressure building into the Ohio and mid Mississippi Valleys through
midweek...dry and pleasant weather will be the story through
Thursday.

Expect much of the period to include abundant sunshine despite some
diurnal cu development each afternoon and mainly clear...comfortable
overnights. One possible exception will be Tuesday afternoon as a
weak upper wave tracks across the lower Great Lakes. With a weakly
unstable airmass present...may be just enough to generate a stray
shower or two over the northern Wabash Valley late day into the
evening. Confidence and coverage far too low for inclusion in the
forecast at this time. Otherwise...northerly flow will maintain a
pleasant airmass with lower humidity values through much of the
period. Could see winds occasionally gust in the afternoons...
especially Tuesday and Wednesday.

Temps...a refreshing change setting up for the region after the heat
and humidity of the last several days. A model blend matches up well
with low level thermals through Thursday. Expect a gradual warmup
through the short term...from the upper 70s to near 80 Tuesday back
into the mid 80s by Thursday as return flow develops. Lows will
remain predominantly in the upper 50s and lower 60s.

&&

.LONG TERM /Friday through Monday/...
Issued at 245 AM EDT Tue Jul 23 2019

Models and ensembles in good agreement that a ridge will remain
strong over the southeast through the long term. However, a cold
front may be close enough for a few thunderstorms to return by next
Monday. Otherwise, 00z GFS QPF from time to time over central
Indiana looks bogus. Prefer, a dry forecast through the weekend.

National blend slightly above normal temperatures, mostly with highs
in the upper 80s, well received.

&&

.AVIATION (Discussion for the 230600Z TAF Issuance)...
Issued at 1208 AM EDT Tue Jul 23 2019

VFR conditions are expected through the period.

With drier air moving in, do not expect fog to be an issue at the
TAF sites.

Scattered diurnal cumulus will develop during the morning hours
Monday and then dissipate during the early evening. Winds will be
around 10kt during the day, and generally lower at night.

&&

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

&&

$$

SYNOPSIS...Ryan
NEAR TERM...Ryan/50
SHORT TERM...Ryan
LONG TERM...MK
AVIATION...50


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