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Area forecast discussion 
National Weather Service northern Indiana
647 am EDT sun Aug 2 2015

Synopsis...
issued at 322 am EDT sun Aug 2 2015

An upper level disturbance and strong cold front crossing the
Great Lakes tonight will spark showers and thunderstorms...some
strong to potentially severe. Ahead of this system...a warm and
windy day is expected with afternoon highs from the upper 80s to
lower 90s.

&&

Short term...(today and tonight)
issued at 322 am EDT sun Aug 2 2015

Stormy lt period shaping up. Rtn of very warm and humid conds expected
this afternoon in association/west eastward fold of staunch plains thermal ridge.
Given expected substantial clearing within deepening warm sector southeastward of
intensifying surface frontal zone shifting out of the upper Midwest and
substantial mixing this afternoon...decided preference lies toward warmer
spectrum of guidance temperatures especially after looking at various 2m forecasts and
will bump accordingly. Otrws probability of precipitation/weather none as capping aloft
intensifies overtop initially drier pocket of ll Theta-E.

Primary attention though centered on southeastward sinking active frontal zone tonight.
By all accounts forcing within intensifying surface frontal zone aligned
west/robust heights falls aloft and sig ll moisture advection out of the corn belt
toward 00z point to what shld be a solid line of strong-severe convn shifting
southward out of Michigan this evening. Southern reach of severe threat in doubt however
tied to lt evening timing and stabilizing boundary layer but northern third
could get walloped west/sig severe pending upstream evolution of conv
line underneath steep eml later this afternoon. Will hold west/prior 60 pop
threshold though as both near and short term guidance vacillates considerably
west/far differing convn scenarios.

&&

Long term...(monday through saturday)
issued at 322 am EDT sun Aug 2 2015

A trend toward below normal temperatures the main story next week as
primary baroclinic zone settles south into the Ohio/middle MS valleys
in response to Hudson/James Bay upper low drift into southeast
Canada...

Round of height falls through the Great Lakes region in this
transition will force a synoptic cold front and associated
diminishing shower/storm chances southeast through the local area Monday
morning. Dry/stable Post-frontal northwest flow then filters in for
later Monday-Tuesday.

Primary upper trough axis looks to relax/shift east by middle to late
week which will allow better potential for upstream shortwaves to
take aim on the region. Resulting fgen/isentropic ascent response
along the aforementioned frontal slope...along with lingering right
entrance upper jet support...warrant periodic rain chances with weak
frontal waves during the Wednesday through early Friday periods.

&&

Aviation...(for the 12z tafs through 12z Monday morning)
issued at 647 am EDT sun Aug 2 2015

VFR conds expected through much of this period. However sharpening
cold front in association/west vigorous disturbance over southern Ontario expected to surge
southeastward lt period...sparking a line of vigorous convn overnight. Timing
uncertainties remain though in both near and short term guidance and as
such have only included a thunderstorms in the vicinity mention in vicinity of terminals. Otrws strong
mixing expected to develop within warm sector southeastward of advg low pressure this
afternoon. Corresponding rapid escalation of ll follow and sig momentum xfer
suggests southwesterly surface gusts at or above 25kts for much of this afternoon.

&&

Iwx watches/warnings/advisories...
in...none.
Michigan...Beach hazards statement from 10 am EDT this morning through
Monday morning for miz077.

Ohio...none.
Lm...Small Craft Advisory from 10 am this morning to 8 am EDT Monday
for lmz043.

Small Craft Advisory from 10 am this morning to 11 PM EDT this
evening for lmz046.

&&

$$

Synopsis...T
short term...T
long term...steinwedel
aviation...T



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