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Area forecast discussion 
National Weather Service Indianapolis in
1026 am EDT Thursday Oct 30 2014


The aviation section has been updated below.


issued at 351 am EDT Thursday Oct 30 2014

A surface and weak upper level wave...followed by a far more
potent upper level low on Halloween...will make for an active
period to end the work week...with the first chances for
snowflakes coming Halloween night...and the coldest air of the
Young season following along for the weekend.


Near term /today/...
issued at 351 am EDT Thursday Oct 30 2014

A weak system will approach the area late this afternoon...and
will have to maintain some slight chance probability of precipitation across the far west
after about 21z. Moisture is a significant limiting factor.

Thicknesses suggest warmer MOS blend is preferable...and expect
highs today to generally be in the middle to upper 50s.


Short term /tonight through Saturday night/...
issued at 351 am EDT Thursday Oct 30 2014

Main focus of the forecast is on Halloween and Halloween
night...when a far more potent upper level low will swing through
the region. Synoptic forcing is adequate but mesoscale forcing in
the form of extremely strong frontogenesis merits the likely probability of precipitation
across much of the forecast area during the day on Friday. While
drier air does move into the area in the wake of the low late
Friday afternoon and into the evening...enough moisture should
linger that...coupled with strong cold advection...and potential
lake enhancement...snow showers will be a threat across the area.
Very warm ground will likely preclude any accumulation as snow
should melt fairly quickly upon contact with the ground...but
could see a dusting on elevated surfaces Friday night.

In addition...winds will be quite strong as pressure gradient
strengthens Friday and Friday night. Could easily see gusts 30 to
35 miles per hour during the afternoon Friday...and perhaps as strong briefly
into the evening Friday night.

As the frost/freeze program for weather forecast office ind ends on November 1st and
some neighbors have also already shut down their programs for the
season...will not issue any freeze headlines at the moment. Day
shift may wish to discuss further...and coordinate again with
other neighbors who have not yet ended their programs on if it is
necessary to issue a headline for the morning of the 1st.

Model blends appear to be handling temperatures relatively well
and few changes were required.


Long term /Sunday through Thursday/...
issued at 351 am EDT Thursday Oct 30 2014

A strong ridge of high pressure will keep conditions dry across all
of central Indiana through Monday. However...the ridge will break
down on Monday night as an upper low moves along the Canadian/U.S.
Border. This system will be responsible for rain chances through
the remainder of the extended period. Regional initialization is
handling pattern well due to good model will not
make any changes at this time. After a chilly start to the long
term period...some warm air advection at the surface will bump highs
into the 50s from Monday through Wednesday. Overnight lows will
generally be in the 30s and 40s.


Aviation /discussion for the 301500z taf update/...
issued at 1026 am EDT Thursday Oct 30 2014

Made minor adjustment to kind taf based on latest trends. No
significant changes made.

Previous discussion follows...
VFR through the period.

Only exception is some fog in the first hour or two at laf.

Increasing midlevel cloud expected as a weak disturbance moving into
the area. Will maintain vcsh mention this evening and overnight.

Winds will be less than 10kt throughout the period.


Ind watches/warnings/advisories...none.



near term...nield
short term...nield
long term...tdud

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