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257
FXUS63 KIND 280446
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1246 AM EDT Fri Jul 28 2017

.UPDATE...
The AVIATION Section has been updated below.

&&

.SYNOPSIS...
Issued at 252 PM EDT Thu Jul 27 2017

A surface low pressure trough and cold front near the I-70
corridor this afternoon will be settling south to the Ohio River
early Friday as high pressure builds southeast into the Great
Lakes. This will result in the precipitation shifting south of our
area by mid day Friday.

A combination of surface and upper ridging of high pressure will
then control the weather for our area with mostly clear skies
starting Friday night, and remaining dry until at least next
Thursday.

Model blend temperatures appear reasonable and were used showing a
trend to below normal temperatures starting Friday, slowly
moderating back to normal middle 80 highs by mid week next week.

&&

.NEAR TERM /Rest of Tonight/...

Issued at 932 PM EDT Thu Jul 27 2017

Quasi stationary frontal boundary is sliding a little bit
southward through central IN this evening. Radar shows some cells
with brief heavy showers rotating southwest to south through area
this evening indicating a possible weak low passed by a few hours
ago, where area of moderate-heavy showers are moving eastward over
our southwest counties and are south of the boundary.

Don`t expect that weak frontal boundary to move much more tonight,
at least not until a mid level trough over MN amplifies and
swings southward then eastward Friday afternoon moving that
frontal boundary out of here as a cold front allowing high
pressure in the are for the weekend.

..Previous discussion...

Some breaks in the clouds this afternoon have helped to develop
some narrow bands of showers and a few thunderstorms. These will
show slight further development as they track east southeast this
evening. Will continue at least a low chance for showers/thunder
through the night as the surface boundary settles slowly south.

A gradual fill-in of the cloud deck should occur tonight as
cooler temperatures on north winds overtake the area. With
humidity remaining high and winds becoming light, patchy fog can
be expected in some areas as well. Minimum temperatures a few
degrees either side of 70 appear reasonable, possibly reaching mid
60s near Kokomo.

&&

.SHORT TERM /Friday through Sunday/...

Issued at 252 PM EDT Thu Jul 27 2017

A fairly sharp upper trough will drop southeast across the Great
Lakes Friday and with it, a low threat for showers or thunder
continuing in our far east and southeast counties at least through
the morning hours Friday. Thereafter, subsidence begins to take
over and solid cloud cover begins to scatter then clear by late
Friday.

Continued drying as the high pressure builds further southeast
into the Great Lakes and Ohio Valley will result in clear skies
Friday night into Sunday. Dewpoints will be falling from mid 60s
Friday afternoon well down into the 50s for the weekend.

Temperature guidance from the models was fairly similar and was
followed, with weekend lows dipping into the 50s along with
daytime highs from the upper 70s Saturday to around 80 Sunday.

&&

.LONG TERM /Sunday night through Thursday/...

Issued at 213 PM EDT Thu Jul 27 2017

Models are in good agreement on the upper pattern through much of
the long term. Have high confidence in dry weather Sunday night
through Wednesday before the pattern changes enough to allow the
next frontal system to approach. Medium confidence that high
pressure slides off to the east and allows a cold front to
approach and bring a return to at least small chances for
thunderstorms to end the week, but low confidence that this
happens before Friday. Stuck with the blended initialization low
pops for Thursday at this time. Temperatures appear to be near
normal through the period with highs in the mid 80s.

&&

.AVIATION /Discussion for the 28/0600Z TAF Issuance/...

Issued at 1240 AM EDT Fri Jul 28 2017

Quasi-stationary frontal boundary lies through central IN this
morning from basically just south of STL - all three of IN stations,
HUF-IND-BMG then through DAY. Most of the precipitation is over
extreme IN with some VCSH around IND. What will be associated now
with the boundary will be calm or light winds and plenty of moisture
around. Check of the blend indicates FG overnight around BMG mainly
after 08Z, then clearing towards morning, or least the ceiling
lifting but stil IFR/MVFR until the MN mid level short wave trough
amplifys and moves through the region during the late morning/early
afternoon on Friday.

&&

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

&&

$$

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