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Area forecast discussion 
National Weather Service northern Indiana
339 PM EDT Wednesday Jul 30 2014

issued at 1049 am EDT Wednesday Jul 30 2014

A series of upper level disturbances rotating around a stationary
low over southeast Canada will cause isolated mainly afternoon
showers and thunderstorms in our area through Thursday. Lows
tonight will be in the 50s... with highs Thursday in the middle to upper


Short term...(this evening through thursday)
issued at 328 PM EDT Wednesday Jul 30 2014

Widely scattered showers and storms will continue to affect much of
the area into early evening away from the Lake Shadow that has once
again worked well inland. By middle evening skies will clear with quiet
conditions returning.

Upper low will finally begin to pull away later tonight into
Thursday taking the core of the coldest air with it. That being said
another weak disturbance will still move through the region with
enough lingering moisture and cold air aloft to allow for isolated
showers and storms...mainly northeast during the afternoon hours
where instability will peak in the 500 to 1000 j/kg of surface based
cape. Highs should edge a degree or 2 warmer than today with
readings in the middle to upper 70s.


Long term...(thursday night through wednesday)
issued at 328 PM EDT Wednesday Jul 30 2014

Upper low near James Bay expected to move slowly east Thursday night...
however an upper level trough should linger across the Great Lakes/Ohio Valley
into Friday... moving slowly east over the weekend. Weak shortwaves
expected to move through the upper trough and across our County Warning Area both
Friday/Sat with weak/moderate diurnal instability resulting in a chance of thunderstorms.
Better chance looks to be Friday when a surface reflection inverted trough
slides east across the area. Weak north-NE low level flow expected in the
wake of the inverted trough Saturday as surface high pressure builds over
the upper Great Lakes. A chance of showers/thunderstorms still warranted for Saturday
as lingering low level moisture should again result in weak/moderate
diurnal instability with lake breeze boundaries meandering through
the area in the afternoon to also focus convection. Given weak steering
flow and limited moisture/instability both days... expect coverage
of showers/storms will be 30-40% at best.

Upper level trough expected to move east across Ohio Sunday shifting
better forcing/instability to east of our County Warning Area. Shortwave moving across
southern Canada early next week should push a slow moving backdoor cold front
south into our area by Tuesday. Moisture pooling along the front may
allow afternoon thunderstorms to form over the area Tuesday. Western ridge expected to
continue to flatten as next shortwave moves over top and across the plains
Wednesday. This may result in scattered thunderstorms along/north of the stalled surface
boundary... mainly over northern portions of the County Warning Area.

Temperatures expected to remain a bit below normal through Saturday... then warm
to at or slightly above normal early next week as modest upper ridging
builds into the area. These warmer temperatures should persist across southern
portions of the County Warning Area at least into Tuesday... with weak cold air advection behind
backdoor cold front probably impacting at least the north-NE portion of the
County Warning Area by Wednesday.


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 137 PM EDT Wednesday Jul 30 2014

VFR conditions expected to dominate the ksbn area as Lake Shadow
has now passed over the Airport resulting in a more stable setup.
At kfwa cumulus will continue to expand somewhat with potential for
widely scattered to scattered showers and storms to develop from middle afternoon
into the early evening as a weak disturbance moves in. Have left
thunderstorms in the vicinity in place given plenty of instability for convection to form
but low confidence on impact at Airport. Otherwise high clouds
will stream across the sky from time to time.


Iwx watches/warnings/advisories...


short term...Fisher
long term...jt

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