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Area forecast discussion 
National Weather Service Indianapolis in
103 PM EDT Friday Jul 11 2014

Update...

The aviation section has been updated below.

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Synopsis...

Issued at 310 am EDT Friday Jul 11 2014

High pressure over the Great Lakes will continue to provide dry
weather to central Indiana through early Saturday. A warm front is
expected to push out of the Central Plains states Saturday
and stall over North Central Indiana through much of the weekend.
This will bring warmer...and more humid air back to central Indiana
for the weekend along with daily chances for showers and
thunderstorms through Monday.

A strong cold front will arrive in central Indiana by the middle
of next week...allowing much cooler weather and unseasonably cool
temperatures for the middle of July.

&&

Near term /rest of today/...

Issued at 1020 am EDT Friday Jul 11 2014

Forecast is on track. Only tweaked grids to reflect current trends.
No significant changes needed.

Previous discussion follows...
dry weather continues today as the surface high pressure system over
the Great Lakes begins to depart to the east. However developing
return flow of warmer air on southerly winds will allow temperatures
and dew points to begin to climb...marking a brief return of
humidity. Highs low to middle 80s.

&&

Short term /tonight through Sunday night/...

Issued at 310 am EDT Friday Jul 11 2014

Late tonight begins another unsettled period as a frontal boundary
approaches the area and then settles across the region for the
duration of this period. Then one upper level disturbance after
another will move across is and produce chances for showers and
thunderstorms. Best chance for probability of precipitation comes Sunday...at the end of the
short term when a very strong shortwave moves into the area. Likely probability of precipitation
were included during this time for all of central Indiana.

&&

Long term /Monday through Thursday/...

Issued at 310 am EDT Friday Jul 11 2014

Ensembles are in good agreement in bringing a fairly strong upper
system for this time of year across the Great Lakes around
Monday...leaving upper troughing over the local area in it wake
through the middle of next week.

Will keep chance probability of precipitation going for Monday in association with the
passage of the upper system. After Monday...a cooler and more stable
air mass is expected to move into the area. Ensembles suggest the
potential for afternoon showers through the rest of the extended
period due to the strength of the upper trough...but at this point
the chances are too small to warrant a mention in the forecast. Will
continue with a dry forecast after Monday.

&&

Aviation /discussion for 11/1800z tafs/...

Issued at 103 PM EDT Friday Jul 11 2014

VFR conditions are expected through this period.

High pressure east of Indiana will continue to provide a dry air
mass over central Indiana for the next 12 hours. Forecast
soundings remain dry and convective temperatures look to be
unreachable. Thus no cumulus is expected and only some high wispy cirrus
clouds may pass in the flow aloft.

Trough of low pressure over the upper Midwest is expected to sag
southeast toward central Indiana overnight and on Saturday. This
will allow the clouds over WI...Illinois and Iowa to advect southeast.
Surface flow also becomes more southerly...allowing for moisture to
arrive. Forecast soundings reveal a top down saturation beginning
late tonight and continuing on Saturday as the trough approaches.
Some instability looks present in the forecast
soundings...allowing for thunderstorm development on Saturday
afternoon...however confidence for precise timing is not high
enough yet.

&&

Ind watches/warnings/advisories...
none.
&&

$$

Synopsis...smf
near term...smf/50
short term...smf
long term....jas
aviation...jp

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