Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 291444

Area Forecast Discussion
National Weather Service Indianapolis IN
1044 AM EDT Mon May 29 2017

Aviation section updated


Issued at 214 AM EDT Mon May 29 2017

Weak fronts will continue to pass Indiana from the west until
Wednesday, when high pressure developing over the eastern USA should
take control of Hoosier weather.

Another frontal boundary is forecast to arrive in Indiana Friday. It
will then become stationary, staying across our state through the


.NEAR TERM (Rest of Today)...
Issued at 1020 AM EDT Mon May 29 2017

Mid level speed max currently dropping southeast from the northern
Midwest. Lift from this feature should start moving into the
northwest zones by the mid to late afternoon hours, spreading
southeast during the evening. Current forecast handles this well.

Will nudge up the highs a bit more today, especially over the
western and southwestern zones, based on this morning`s upper air

Previous discussion follows.

The main issue is POPs.

For several runs, the models have been hinting about a weak
disturbance with moderate instability coming through late today.
Things aren`t nearly as impressive as yesterday, but some models
fire something while others don`t. The slight chance for the
central and north from consensus looks good by allowing for
something, but not hitting it hard.

While we are mostly clear early this morning, the day should be
partly cloudy. Satellite shows approaching cloud bands, and wet
ground should promote diurnal cumulus.

At Indianapolis, consensus produced a perfect temperature forecast
yesterday. In the same basic situation, it ought to work well


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

Issued at 214 AM EDT Mon May 29 2017

The main forecast problem remains POPs.

Models continue to agree that early in the period a series of
weak fronts will pass. They differ about POPs, a typical problem
with subtle features. Consensus will be used to minimize error,
but those could still be as high as 20 percent

Besides up and down rain chances, expect partly cloudy skies.

Wednesday should finally bring dry weather and clearing as all
models have a surface high building over the area.

Given consensus POPs will be used, so will consensus temperatures.
The underlying thermal fields are fairly close, so possible errors
should be limited to 1-3 degrees.


.LONG TERM /Thursday through Sunday/...

Issued at 255 AM EDT Mon May 29 2017

GFS and ECMWF models have generally a mid/upper level trough over
much of the northeast quarter of the U.S., and another trough
extending southward over the western states with a ridge over the
northern high plains into south central Canada. A weak trough is
over the southern high plains of NM and west TX.

Given the variance in the solutions, there is low confidence in
the forecast. As it is right now, looks like chances of showers
and thunderstorms will be carried each day from Thursday afternoon
through the rest of the period as area will be under the influence
of the mid/upper level trough over southeast Ontario and the
Great Lakes. High pressure moves off to the east by Friday
resulting in a southerly flow going into the weekend. Temperatures
to begin June will be in the upper 70s during the day and in the
low-mid 60s at night.


.AVIATION /Discussion for the 291500Z Tafs/...

VFR Conditions are expected to persist through the afternoon.
Forecast soundings and Time heights remain dry through much of the
afternoon amid the broad but weak cyclonic flow situated far
north. Tafs now include a small VCTS mention early this evening as
a weak wave is expected to pass. This seems reasonable given the
steep but dry soundings...however confidence is low.

Previous Discussion Below

(Discussion for 291200Z TAFs)...

Issued at 628 AM EDT Mon May 29 2017

Drier air than recently will cause VFR to predominate, with either
no ceilings or ceilings above 10 thousand feet. A weak front from
the west may cause isolated thunderstorms from 20Z-06Z. The
chance of storms is too low to put in the TAFs at this point.

Expect winds to be southwest 5-15 knots today and west 5-10 knots




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