Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 201645

Area Forecast Discussion
National Weather Service Indianapolis IN
1245 PM EDT Thu Oct 20 2016

The AVIATION section has been updated below.


Issued at 355 AM EDT Thu Oct 20 2016

An upper level trough will swing through the region today,
ejecting a stalled frontal system off to the east, but not before
providing widespread showers and perhaps a few rumbles of thunder
across the area today, with some potential for showers lingering
tonight. Dry weather will return Friday into early next week as
broad surface high pressure dominates the area.


.NEAR TERM /This afternoon/...

Issued at 950 AM EDT Thu Oct 20 2016

Surface analysis late this morning shows low pressure over Western
Kentucky...with a frontal boundary stretching from eastern Ohio to
Arkansas. Water vapor imagery shows a plume of moisture along the
front...stretching from Texas across Indiana to the eastern Great
Lakes. A upper trough was found across the Central Plains
states...digging eastward. Radar shows extensive precipitation
stretching from SE Michigan...across central Indiana to Arkansas.

HRRR shows the precipitation band will continue to advect East/SE
through the course of the afternoon...passing across all of the
forecast area. Forecast soundings show a saturated column across
Indiana. Good lift and forcing remains present as the upper trough
the west continues to approach and the surface low over Western
Kentucky is expected to slide slowly Northeast across southern
Indiana as the day progresses.

Thus have decided to raise pops to near 100 percent at all
locations as precip will be expected. Given the expected clouds
and rain through the day...little to no sunshine and heating will
expected. Will use nearly steady state temperatures. Best chances
for any thunderstorms will remain across southern Indiana...closer
to the front where a bit warmer air and better instability is
located. That being said...a isolated rumble of thunder anywhere
in central Indiana cannot be ruled out.


.SHORT TERM /Tonight through Saturday Night/...
Issued at 355 AM EDT Thu Oct 20 2016

Will hold onto some lingering pops mainly early in the night
tonight, with the remainder of the short term likely to be dry
under the influence of high pressure. Cannot entirely rule out
some lake effect sprinkles or showers Friday but will limit this
potential for now.

Consensus temperatures appeared reasonable throughout.
Temperatures will bottom out Saturday morning in the upper 30s.
Cannot completely rule out frost potential in sheltered locations,
but wind should stay up enough to preclude a widespread frost, and
thus will not mention in grids at this time. Temperatures will
begin to recover as the weekend wears on and should be back to
near normals by the end of the weekend.


.LONG TERM /Sunday through Wednesday/...
Issued at 249 AM EDT Thu Oct 20 2016

Progressive upper level flow aloft continues into the middle of
next week across much of the continental U S. With large high
pressure drifting to the east coast by the end of the
period...expect quiet and pleasant autumn weather for the region
into Wednesday.

After a mild day Sunday with highs in the upper 60s and lower 70
for most of the area...weak low pressure and an associated
frontal boundary will zip through the Great Lakes Sunday night.
With model soundings and RH progs showing deep subsidence and dry
air lingering over the Ohio Valley...the main impact from the
frontal passage will be to usher slightly cooler air back into the
forecast area to start the week. Highs in the 60s Monday and
Tuesday will warm back into the upper 60s and lower 70s by
Wednesday as low level flow veers to southerly on the back side of
the surface ridge.

An upper wave with an associated surface low will track into the
lower Great Lakes Wednesday and Wednesday night bringing the next
chance for rain showers. With extended models not yet in a
consensus on timing the arrival of the system...took a blended
approach with low chance pops late Wednesday.


.AVIATION (Discussion for the 201800Z TAF Issuance)...
Issued at 1245 PM EDT Thu Oct 20 2016

IFR conditions expected early in the period at some sites,
otherwise MVFR conditions expected through much of the period.

Rain will continue at most sites this afternoon, with perhaps a
break late afternoon. More rain is possible this evening before the
system exits.

Upstream conditions show IFR still likely at some sites early in the
period, then they should lift to MVFR. While there may be some
variability to VFR at KLAF at times, the other sites should then
remain MVFR through at least the evening hours. KIND should remain
MVFR into the morning hours Saturday.




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