Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Indianapolis in
556 PM EDT Sat Jul 23 2016

Update...
the aviation section has been updated below.

&&

Synopsis...
issued at 330 PM EDT Sat Jul 23 2016

A broad ridge of high pressure remains in place across much of the
country, with a hot and humid airmass across central Indiana. This
heat will last through tomorrow, before a cold front approaches
the area and allows a slight cool down back toward seasonal
normals and brings slightly higher thunderstorm chances to the
region.

&&

Near term /tonight/...
issued at 330 PM EDT Sat Jul 23 2016

With some indication that the cumulus field across the area has
been a bit congested at times, will maintain a 15 pop for
potential isolated pop up storm through 23z. Otherwise, will keep
things dry until late tonight, introducing low pops across the
north after 09z as some development may occur on old boundaries to
our northwest and move into the area late.

Temperatures should be similar to last night, and consensus
numbers handle this well. Likely some fog late but will leave to
evening shift to decide if the visibilities will merit a mention
in the grids.

&&

Short term /Sunday through Tuesday/...
issued at 330 PM EDT Sat Jul 23 2016

Frontal boundary will finally begin to approach the area late
Sunday. Will need slight chance or low chance pops across the area
tomorrow, ramping them up Sunday night into Monday as the front
moves through the area.

Don't see anything beyond a pulse severe threat at any time during
the period, as dynamics will be weak.

Concern for tomorrow will be another day of heat and humidity.
Thunderstorms, if they are more expansive than expected, could
throw a wrench in the plans, but as of now expect another day with
highs in the 90s and heat index values approaching 105, so have
extended the heat advisory through 8 PM Sunday.

&&

Long term /Tuesday night through Saturday/...
issued at 200 PM EDT Sat Jul 23 2016

Timing of best pops related to various upper waves and surface
reflections will be the main difficulty with the long term.
However, good confidence that a mean Mississippi Valley trough,
related upper disturbances and nearby surface features will interact
with a moist and unstable atmosphere and result in thunderstorm
chances mid week through next Saturday. Regional blend reflects this
well. Lowest pops will be Tuesday night, when a stationary front is
expected to be south of the Ohio River. Look for only small chances
near and south of Terre Haute and Bloomington, then.

Thermal pattern favors near normal blend temperatures with highs in
the 80s and lows mostly in the mid and upper 60s.

&&

Aviation /discussion for the 24/0000z taf issuance/...

Issued at 546 PM EDT Sat Jul 23 2016

High pressure will remain over the Tennessee Valley and over the
upper Great Lakes for Sunday. In between will be a frontal
boundary over extreme northern in that will meander north-south
across that area. As the strong ridge of high heights breaks down
a bit due to an approaching trough over the western Great Lakes,
there could be scattered -tsra in the afternoon on Sunday
effecting klaf and maybe kmie. Not much confidence at this time
whether the -tsra activity makes it further south; have a bit more
confidence that will wait until Sunday night/Monday from khuf and
kind.

Again due to light winds at the surface overnight, look for just
some light haze/fog at many locations to bring MVFR conditions
Sunday morning before scattered -tsra effects mostly klaf/kmie during
the afternoon.

&&

Ind watches/warnings/advisories...
heat advisory until 8 PM EDT Sunday for inz021-028>031-035>049-
051>057-060>065-067>072.

&&

$$

Synopsis...nield
near term...nield
short term...nield
long term...mk
aviation...dwm

National Weather Service Glossary of Abbreviations