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Area forecast discussion 
National Weather Service Indianapolis in
314 PM EDT Wednesday Jul 30 2014

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


issued at 308 PM EDT Wednesday Jul 30 2014

Central Indiana will continue to be under the influence of low
pressure centered over eastern Ontario while a large ridge of high
pressure resides over the western states. This pattern will result
in slightly below normal temperatures through the period and daily
chances for showers and isolated thunderstorms through the first
half of the weekend. However...conditions will be dry for most of
the extended as aforementioned ridge moves closer to central Indiana.


Near term /rest of this afternoon through tonight/...

Issued at 308 PM EDT Wednesday Jul 30 2014

Widely scattered showers have developed across the central County Warning Area along
an associated short wave moving through the upper trough. Anticipate
this activity to continue through 00z around which it will gradually
dissipate with loss of daytime heating.

For tonight skies will begin to clear out and conditions should be
dry. May have some patchy fog in some of the outlying areas...but
does not appear to be widespread enough to mention in the forecast
at this time. MOS blend of low temperatures appears reasonable yielding
lows in the upper 50s.


Short term /Thursday through Saturday/...

Issued at 308 PM EDT Wednesday Jul 30 2014

The low pressure over eastern Ontario will remain somewhat stationary
through Friday and finally push off to the east on Friday
evening...dragging a cold front through the area. Thursday will be
the driest day of the period with only a slight chance possible.
(Diurnally charged). By Friday chances ramp up to high end
chances...bordering likely. Confidence is fairly high in this
event of a frontal passage...but models have not been very refrained from going much higher at this moment. A
secondary front is looking more likely on Saturday as
well...providing additional probability of precipitation for the area before the ridge
builds back over the region.

A weak warming trend will be in store for central Indiana as we break
out of the northwest flow...however temperatures still will be lagging a few
degrees below climatology.


Long term /Saturday night through Wednesday/...

Issued at 251 am EDT Wednesday Jul 30 2014

Long term focus will be on lifting trough ending rain and warming

One last short wave that will deepen the trough over Great Lakes
Friday finally lifts east by Saturday night. Upper ridging
overtaking the Great Lakes and Ohio Valley for Sunday through
most of Tuesday translates to drier and warmer period for central
Indiana. However...a combination of weak short wave energy
dropping southeast into the eastern Canadian trough by Tuesday coupled
with some monsoonal moisture lifting over the top of The Rockies
upper ridge spell a return to potential storminess midweek next
week as the surface boundary wavers between the lower Great Lakes
and the I-70 corridor.

With the trough lifting out...temperatures return to seasonal
values and as ridge and drying take further hold...a return to
above normal temperatures late this period.


Aviation /discussion for 301800z tafs/...

Issued at 1233 PM EDT Wednesday Jul 30 2014

Forecast period will be mainly VFR with wind under 10 kts.
Exception periods include isolated thunderstorms through Sundown
possibly causing brief MVFR visibility then daybreak localized
MVFR fog...especially if a taf site sees rain.

Satellite shows a very weak trough axis rotating southeast across
central Indiana right at taf issuance time and a second weak
trough over southern Michigan and moving southeast. Indianapolis
appears to be the site most likely for any thunderstorms today
though the tail end of each wave could clip klaf or kbmg. Have
only included kbmg in that scenario.

Winds dropping to near calm under mostly clear sky to yield
dewpoint depressions of one to four degrees suggestive of MVFR
fog...especially at the more rural sites of klaf khuf and kbmg.


Ind watches/warnings/advisories...


near term...smf
short term...smf

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