Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 210814

Area Forecast Discussion
National Weather Service Indianapolis IN
414 AM EDT Wed Jun 21 2017

The AVIATION Section has been updated below.


Issued at 251 AM EDT Wed Jun 21 2017

High pressure from Indiana to the southeast coast is going to rule
Hoosier weather through Thursday night. Friday we`ll be passed by a
cold front. Friday night high pressure should arrive from the
northwest.  The high is likely to dominate our weather for several
days as its center shifts to the eastern seaboard.


.NEAR TERM (Today)...

Issued at 251 AM EDT Wed Jun 21 2017

The main issue is POPS.

The models tend to agree today will be dry. They also agree a weak
boundary and some moisture will remain over the area, on the day
with literally the highest sun angle of the year. We currently
have more rain than there `should` be.

There will need to be an early morning period with relatively high
POPs. For the actual today period, the comparatively moist MET,
which gives a chance or slight chance in the areas with the most
moisture, will be used.  Skies should be partly cloudy under diurnal

Given low confidence about POPs, there is limited confidence about
temperatures. Consensus should minimize errors. These may be 2-3
degrees based on the range between different forecast methods.


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

Issued at 251 AM EDT Wed Jun 21 2017

POPs are the main forecast problem.

The models agree in many ways. However we are going to be affected
by a tropical system from the Gulf--very atypical so early in the
summer. Such systems are notoriously challenging for the models.

Currently there is no reason to deviate from the consensus POPs.
These have precipitation likely by Friday, with drier weather
afterward. However confidence is the forecast is low. POPs may
need to be adjusted by 20 percent from those issued today.

As with POPs, there is no reason to vary from consensus with
temperatures, and confidence in them is low. Potential errors are
2-4 degrees.


.LONG TERM /Saturday through Tuesday Night/...

Issued at 311 AM EDT Wed Jun 21 2017

Latest models have backed down on precipitation chances for the
weekend with central Indiana actually dry on Saturday. Friday`s
cold front is progged to be far enough south by Saturday to result
in a dry forecast. Sunday, there have been some model
inconsistencies in regard to showers and thunderstorms with an
upper wave skimming the northern portions of the area. For now,
latest Superblend initialization is trending toward a dry
forecast, and there is not enough support to deviate from that at
this time. Further out, a strengthening ridge over the Rockies
will result in dry conditions through the end of the extended
period. The only caveat may be some isolated showers on Tuesday
afternoon in association with a weak upper wave. As far as
temperatures, expect below normal numbers with a transition back
to a warming trend at the very end of the period.


.AVIATION (Discussion for 210900Z TAF update)...

Issued at 415 AM EDT Wed Jun 21 2017

Upper level vorticity lobe currently sagging southeast through
central Indiana is expected to pass to the southeast of the
terminals by 12Z. As a result, remaining shower activity in the
vicinity of the terminals should end over the next couple of

Otherwise, expecting diurnal cloud development based around 030
towards the midday hours. Winds should be less than 10 knots.
Direction will be somewhat variable, but primarily from the




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