Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 271403

Area Forecast Discussion
National Weather Service Indianapolis IN
1003 AM EDT Thu Jul 27 2017

The NEAR TERM Section has been updated below.


Issued at 152 AM EDT Thu Jul 27 2017

A slow moving cold front from the northwest will cross Indiana from
today into Friday.  After that the same high pressure system should
dominate our weather well into next week. The center of this high ix
expected to be over the upper Great Lakes Friday evening, and
over the Appalachians by Tuesday.


.NEAR TERM /Rest of Today/...

Issued at 956 AM EDT Thu Jul 27 2017

Have adjusted rain chances to reflect current and projected radar
data. Some areas did pick up 0.5 to 1.0 inch rains overnight but
nothing heavier and these were limited in coverage.

Limited instability and lack of shear are limiting very moist
atmosphere from generating widespread heavy rain for Indiana.
 Still expect scattered showers and as daytime heating
progresses, though limited, isolated thunder may still come into

Though we don`t have far to go to reach 80, that may still be a
struggle given extensive cloud cover and the occasional showers.
Have kept max temps there for now but they may need a downward
adjustment to upper 70s at mid day update.


.SHORT TERM (Friday through Saturday night)...

Issued at 152 AM EDT Thu Jul 27 2017

The main issue is the chance of rain Friday.

The models agree an unseasonably strong wave aloft will pass, but in
general have been struggling with precipitation forecasts lately.
MOS seems low considering the intensity of the system. The consensus
forecast will be used because that`s usually best in complex
situations, but confidence in Friday`s forecast is low. POPS may
need to be changed by 20 percent.

Beginning Friday night clear weather should develop as all models
take the wave aloft east of Indiana.

Confidence about Friday`s temperature forecast is low because of the
uncertainty about rain. A consensus will be used, with possible
errors of 4 degrees.  Confidence is higher about temperatures
Saturday and Saturday, with the models in alignment about cool high
pressure over Indiana. Consensus should be accurate to within 1-3


.LONG TERM /Sunday through Wednesday/...
Issued at 233 AM EDT Thu Jul 27 2017

An amplified upper level flow pattern will exist over the
country as July turns to August...with the persistent heat ridge
retreating into the western U S while a broad trough aloft lingers
east of the Mississippi River into midweek anchored by an upper
low over the central Appalachians. The result will be a high
confidence forecast through most of the extended with dry and
seasonable conditions.

The exceptional weather that develops over the weekend will
continue into early next week as a broad surface ridge and general
N/NE flow through the period maintains dry conditions and
comfortable humidity levels. Highs will gradually warm through the
period as low level thermals modify...but overall expecting
afternoon temperatures in the low to mid 80s. Overnights will be
pleasant and cool in the upper 50s to mid 60s.

An uptick in moisture and humidity by Wednesday may be enough to
generate a few storms in the afternoon...but overall confidence is
low in any precip impacts. Expect a greater impact from rain and
storms just beyond the 7 day as an approaching frontal boundary
moves into the Ohio Valley late next week.


.AVIATION /Discussion for 271200Z TAF Issuance/...
Issued at 631 AM EDT Thu Jul 27 2017

MVFR ceilings possible at times today and again late tonight.
Visibility restrictions within convection through this
evening...otherwise VFR expected.

Showers are generally scattered and lighter in nature early this
morning with the greater coverage and intensity to convection from
the lower Wabash Valley back west into Missouri. Expect minimal
impacts from convection for the next few hours with the exception
of KBMG and KHUF which may see impacts from current precip located
over the lower Wabash Valley.

Expecting an increase in convective development over the region
into the afternoon with a low level jet draped over the Ohio
Valley and deep moisture present. With lower than desired
confidence with respect to timing and location of convection...
plan on keeping VCTS mention at all terminals with prevailing
shra specifically at KBMG and KHUF later today where potential
for greater convective coverage will exist in closer proximity to
the axis of highest precip water values. Wind direction should
largely be out of the southwest through the day.

Even lower confidence regarding precip potential this evening into
the early overnight as most recent model guidance holding up axis
of deeper moisture over the southern half of the forecast area
even as low pressure organizes and moves into western Kentucky.
Will maintain a VCTS mention through the evening but the overall
trend should be towards drier conditions overnight as high
pressure over the western Great lakes begins to exert its
influence. Model soundings supporting an inversion trapping
lingering low level moisture in the predawn hours...with low
stratus developing. Winds will veer to northerly overnight.




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