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Area forecast discussion 
National Weather Service northern Indiana
705 am EDT Friday Jul 3 2015

issued at 329 am EDT Friday Jul 3 2015

A weak low pressure system moving east along a stationary front
over the Ohio Valley may cause a few showers over central Indiana
and Ohio today... otherwise high pressure over lower Michigan will
continue to provide fair weather across the area with highs mainly
in the middle 70s. The Ohio Valley low will move east tonight with
the lower Michigan high sinking slowly south into our area...
resulting in clearing skies... light winds... and cool
temperatures with lows mainly in the middle 50s.


Short term...(today and tonight)
issued at 329 am EDT Friday Jul 3 2015

Shortwave over southern Iowa early this morning will move across our area this
aftn/eve. Airmass across our area rather dry and stable at this time...
however deeper moisture not too far removed as evidenced by scattered
showers developing over central Indiana early this morning in area of weak
low level isent lift. NAM/GFS/ECMWF have recently all trended
farther north with track of middle level circulation and associated
cool pool/moisture advection across our area today which may allow
for some weak instability to develop across southern portions of the County Warning Area
during the day and with some support from latest high-res
convective allowing models... have added a slight chance of showers
to southern tier of counties...mainly this afternoon. Slow warming trend
should continue across northern portion of the County Warning Area today as rather stagnant
airmass associated with surface high over Michigan continues to modify... however
considerable cloud cover should limit warmup across southern areas...
expect highs mainly in the m70s across the area.

As shortwave moves to the east of the area tonight...surface high over Michigan
should move slowly S-southeast into our County Warning Area providing clearing skies and
good radiational cooling with lows expected mainly in the m50s.


Long term...(saturday through thursday)
issued at 329 am EDT Friday Jul 3 2015

A quiet/warmer Holiday weekend is in store for the local area as
upper ridge amplifying into the western Great Lakes helps maintain
high pressure at the surface. This will occur in advance of a western
Canada upper trough that will eventually force a cold front through
the region later Monday night-Tuesday per last several model cycles.
Modest moisture return/building instability in advance of this
feature support higher 00z model consensus probability of precipitation during this time.
Large scale flow becomes more zonal by Wednesday-Thursday in wake of
upper trough. Subsidence with frontal boundary forced south into the
Ohio Valley may support a dry/cooler Wednesday...with better precipitation
chances returning late in the week as front attempts to lift back
north in advance of the next convectively aided shortwave.


Aviation...(for the 12z tafs through 12z Saturday morning)
issued at 703 am EDT Friday Jul 3 2015

Recent amdar soundings and surface observation from FWA suggests low level
wind fields sufficiently mixed at this time to remove threat of low level wind shear from
taf. Dry airmass associated with high pressure ridge over Michigan
should keep scattered rain showers south of terminals this taf period as Iowa
shortwave moves east across the area. Surface high expected to move S-southeast
tonight providing good radiational cooling. NAM soundings suggest
potential for some ground fog toward dawn but GFS considerably
drier in low levels so for now left out of tafs with VFR forecast
throughout the period.


Iwx watches/warnings/advisories...


short term...jt
long term...steinwedel

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