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Area forecast discussion 
National Weather Service Indianapolis in
317 am EDT sun Sep 21 2014

the synopsis...near term...short term and long term sections have
been updated below.


issued at 313 am EDT sun Sep 21 2014

A cold front will push southeast of Indiana later this morning and
take any rain chances with it. By this afternoon...another cool
Canadian high pressure system will begin to build across the region.
This will bring dry weather along with seasonable temperatures to
Indiana for much of the next work week.


Near term /today/...

Issued at 313 am EDT sun Sep 21 2014

This afternoon through the rest of the 7 day forecast period is
looking fantastic!

As of 07z this morning the cold front lagging a bit based on
earlier model timing. Still only widely scattered showers with a
few isolated thunderstorms are working their way as a thin line
across the middle of the forecast area. Increased probability of precipitation through 15z
across the far southern counties based on the slower frontal
passage and only included isolated thunder at this time. Based on
latest trends of convection weakening may need to drop mention
from the forecast later this morning.

By this afternoon cold air will begin advecting over the region and
northwest winds will gust around 20-22kt. Some scattered cumulus is possible but
otherwise skies will be mostly clear to partly cloudy. Based on the
cold air advection went slight lower with guidance for highs ranging
upper 60s (north) to middle 70s (south).


Short term /tonight through Tuesday tonight/...

Issued at 313 am EDT sun Sep 21 2014

Cold air advection is expected to continue into Monday night. It is
only by Tuesday that the surface high is expected to settle over
central Indiana...allowing a more easterly or southeasterly flow to
develop. For the next few nights good radiational cooling is
expected and thus trended slightly lower with overnight lows. Dry
weather and cooler highs in store for Monday and around 70 for


Long term /Wednesday through Saturday/...

Issued at 313 am EDT sun Sep 21 2014

Model ensembles maintain a strong upper ridge over the upper Midwest
and Great Lakes through the period and a surface high pressure
system over the eastern Great Lakes and southern New England.

The GFS indicates some moisture may push north into the Ohio Valley
by the end of day 7 as the surface high and upper ridge retreat a
little to the east. However none of the other models indicate this
yet. Expect dry and mild weather will continue through day 7. If
the GFS is right...low probability of precipitation may begin after day 7.

Models indicate 850 mb temperatures will be from +13 to +17 through
the period. This would translate to highs in the middle to upper
70s and lows mostly in the 50s.


Aviation /discussion for the 210600z taf issuance/...
issued at 1235 am EDT sun Sep 21 2014

Cold front will drop southeast across central Indiana overnight and
Sunday morning and should reach laf and huf after 09z and ind and
bmg after 12z. Radar trends and rapid refresh reflectivity suggest
the storms should be south of laf at 06z...ind and bmg around 08z
and bmg around 09z. Will wait until the last moment to see if
thunderstorms in the vicinity...vcsh or a tempo of either look like the best bet.

Could see some low stratocu with the front...but prefer scattered
MVFR with VFR ceilings. This afternoon...will likely see VFR diurnal
ceilings at ind and laf with only scattered VFR at huf and bmg based
on cumulus development forecasts.

Winds will veer from southwest to west to northwest
with sustained gradient winds near 10 knots overnight and
increasing to 10 to 15 with gusts to around 20 this afternoon.


Ind watches/warnings/advisories...


near term...smf
short term...smf
long term....jeh

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