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Area forecast discussion 
National Weather Service Indianapolis in
727 am EDT Friday Jul 31 2015

the aviation section has been updated below


issued at 249 am EDT Friday Jul 31 2015

A weak front could bring some isolated thunderstorms to central
Indiana this afternoon and evening. Another frontal system will
bring more chances for rain Sunday into next week. Near to above
average temperatures into the weekend will give way to below average
readings next week.


Near term.../today/
issued at 249 am EDT Friday Jul 31 2015

The area will remain in northwest flow aloft today. This will allow
a weak cold front to move into the area this afternoon and evening.
Overall moisture is quite limited...but some higher dewpoints may
pool right along the front as it moves through.

NAM/WRF/WRF-nmm models all generate some scattered convection with
the front...while most other models are dry. Given NAM propensity
for overdoing dewpoints...would usually keep forecast dry for today.

However...Storm Prediction Center has placed much of the area in a marginal risk for
severe today...and northwest flow is infamous for generating
convection when you think it will not happen.

Thus will introduce slight chance probability of precipitation across the north half of the
area late this afternoon. Will word as isolated to reinforce the
limited coverage.

For temperatures stuck with a blend of MOS numbers as there should
be a good amount of sun today ahead of the front.


Short term.../tonight through Sunday night/
issued at 249 am EDT Friday Jul 31 2015

Focus is on chances for rain through the period. Models are close
enough that a blend was used.

The weak front will continue to slide through the area this evening.
For same reasons as noted in the near term section will introduce
slight chance probability of precipitation this evening. With loss of heating and front
exiting the area convection should end by midnight.

Saturday will remain dry...but another upper impulse will move
toward the area Saturday night in the northwest flow aloft.
Introduced some slight chance probability of precipitation far northwest late in the night.

Upper waves combined with an approaching front will keep rain
chances around Sunday into Sunday night. Forcing/moisture are such
that only low chance probability of precipitation look warranted at this time.

Generally stuck with a blend of MOS for temperatures as they look
reasonable given expected conditions.


Long term /Monday through Thursday night/...

Issued at 337 am EDT Friday Jul 31 2015

Periodic chances for showers and thunderstorms will be possible
throughout the extended period as several disturbances traverse
the area. Aloft...a broad low pressure system will encompass much
of eastern Canada...and weak waves rotating through that low will
affect central Indiana at times. Meanwhile...a cold front at the
surface will track across the forecast area on Tuesday...stalling
over southern Indiana through Wednesday night. This will provide
another area of convective development. Temperatures through the period
will start out around normal and then fall below normal by


Aviation /discussion for the 31/1200z taf update/...

Issued at 719 am EDT Friday Jul 31 2015

A weak frontal boundary will move through taf sites
this afternoon and evening...possibly triggering some isolated
showers and thunderstorms. However...chances are too low to
include mention in tafs at this time and will have to be re-
addressed with the 18z issuance. So...VFR conditions are expected
to be the prevailing flight category for the duration of taf
period for now. Winds will be northwesterly and will increase to
10 to 13 kts during frontal passage this afternoon.


Ind watches/warnings/advisories...none.



near term...50
short term...50
long term....tdud

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