Area Forecast Discussion
Issued by NWS Indianapolis, IN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KIND 162251

Area Forecast Discussion
National Weather Service Indianapolis IN
551 PM EST Thu Nov 16 2017

The AVIATION Section has been updated below.


Issued at 210 PM EST Thu Nov 16 2017

High pressure is going to be over Indiana into Friday, with a
strong cold front expected to cross Friday night and Saturday.
High pressure is going to return by Sunday. Another cold front
should pass Indiana Tuesday. Wednesday and Thursday the Hoosier
state will be once again under high pressure.


.NEAR TERM (Tonight and Friday)...

Issued at 210 PM EST Thu Nov 16 2017

High pressure is going to cause dry weather, except for a small
chance for showers in the northwest late Friday.

Clouds have been eroding in the southwest today. Once the sun goes
down, that area should be clear the rest of the night. While the
northeast should eventually clear, boundary layer moisture forecasts
suggest this will take time. Partly cloudy is a better forecast
there. The entire CWA is likely to see sun in the morning Friday,
with increasing clouds in the afternoon ahead of the next system.

Considering last nights lows and that there will be less cloudiness
tonight, a MOS consensus looks OK for lows. A MOS consensus also
looks good for highs Friday allowing for morning sun and rather
strong warm advection ahead of the approaching powerful system.


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

Issued at 210 PM EST Thu Nov 16 2017

There is good model agreement on the basic fields.

Confidence is high with the POPs. Showers are on tap Friday night
and Saturday.

Both the GFS and the NAM bring in a lot of CAPE aloft. Thunderstorms
may occur as soon as Friday night. It is likely we will see them
Saturday. With a very strong flow aloft, some storms could bring
gusty winds to the surface.

There is good confidence precipitation will end before midnight
Saturday. There is less confidence about what it will be as it ends.
Considering incoming temperatures, showers of either rain or snow
are possible. There is little or no chance of snow accumulation.

Despite model agreement, there is limited confidence with the
temperature forecast. Friday night and Saturday minor timing
differences with a strong front could make a big difference in highs
and lows. Errors of 6 degrees are possible. Potential errors drop to
4 degrees Saturday night and Sunday when the front will be to the

The blend wind forecast for Saturday was adjusted upward.
Considering the blend often has a low bias, and the strength of the
pressure gradient, MOS winds were preferred.


.LONG TERM /Sunday Night Through Tuesday/...

Issued at 227 PM EST Thu Nov 16 2017

Dry and cool weather will be expected through this time. ECMWF
suggests strong High pressure remaining over the region on Sunday
night through Tuesday. A weak cold front looks to pass across the
area on Tuesday Night and Wednesday...However the ECMWF keeps best
forcing across the Great Lakes and point north...and the forecast
builder responds with a dry forecast as moisture appears lacking.

Another High pressure system is then suggested to arrive by the
ECMWF on Wednesday Night into Thursday, bringing more dry weather.


.AVIATION (Discussion for 170000Z TAF Issuance)...
Issued at 551 PM EST Thu Nov 16 2017

Expect the low clouds to scour out after 05z as surface high
pressure shifts east of the terminals and an upper ridge moves
overhead. That said, confidence in exact timing is low but
confidence in the overall trend regarding flying conditions is good.

Much or all of the daylight hours tomorrow should feature just high
and then mid clouds well ahead of a central Plains system. However,
a warm front will move in from the west with MVFR overrunning rain
likely after 00z Saturday.

Light and variable wind will become southeast and south to near 10
knots after 15z Friday.




AVIATION...MK is the U.S. government's official web portal to all federal, state and local government web resources and services.