Scientific Forecaster Discussion
Area forecast discussion
National Weather Service northern Indiana
745 PM EDT Tuesday Jul 7 2015
issued at 740 PM EDT Tuesday Jul 7 2015
A cooler and less humid night is expected with variably cloudy
skies. Lows will be in the middle 50s to lower 60s. Wednesday will
start out dry across the area...with precipitation chances
returning in the afternoon and especially Wednesday night. Highs
on Wednesday will only be in the lower to middle 70s.
Short term...(this evening through wednesday)
issued at 409 PM EDT Tuesday Jul 7 2015
Cold front continuing to push through the area this afternoon.
With little remaining instability along/ahead of this
boundary...went with an isolated T mention through 00z across the far
southeast forecast area.
Front will move out of the area this evening...with precipitation gradually
ending through midnight. High pressure and drier air will push into
the area overnight. Sky cover will vary from mostly clear across the
northern part of the forecast area to mostly cloudy across the
southern part overnight. No major changes to previous min T forecast
for tonight...still expecting lows in the middle 50s to low 60s.
The aforementioned front will begin to migrate back north into the
area on Wednesday...in response to deepening low pressure ejecting
NE from the Southern Plains. Forecast reflects a gradual increase in
probability of precipitation from south to north through the day on Wednesday. Decent
moisture return is noted into the southern part of the area through
the afternoon...however the best forcing will remain southwest of
the area until after 00z. Therefore...went with probability of precipitation in the chance
range through 00z.
Long term...(wednesday night through tuesday)
issued at 409 PM EDT Tuesday Jul 7 2015
Potent southern stream disturbance over West Texas this afternoon will
lift out into the southern Great Lakes Wednesday night. Aggressive Theta-E
advection northward of poleward of 50kt low level jet shld promote vigorous ascent
overtop northward rtng frontal boundary and expect widespread rain/embedded
thunder as a result. Thus bridged probability of precipitation higher all areas
west/potential for another round of heavy rain especially shld closed low
level cyclonic circ indeed develop as many model solutions show.
Otrws this system quickly exists northeastward on Thursday and minors out in
prevailing downstream zonal follow. Difficult temperature forecast west/lingering but
decaying cloud cover in the afternoon and Post frontal cold air advection wedge yet kept
west/prior notion of generally middle 70s.
Brief low amplitude ridging follows through Friday before giving way to
another SW disturbance ejecting northeastward out of western US trough. Pop
details remain quite murky from middle-lt period west/sig detail diffs noted amg
medium range guidance suite. As such essentially smoothed blended
solution to eliminate noise but retain otrws implied unsettled tone
especially in light of penchant for a ring of fire pattn to develop along NE
periphery of retrograding upper ridge. Within this
transition...seasonable warm temperatures expected to rtn this weekend and
Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 739 PM EDT Tuesday Jul 7 2015
Satellite shows skies clearing at issuance time but MVFR ceilings
still over kfwa for another hour or two before clearing works
through. Winds will become light overnight but dew points already
into the upper 40s and lower 50s as drier air works in. For now
kept mention of br out of tafs with preference toward the drying
and light gradient and only patchy br development. Kept Wednesday
VFR and dry for now but rain could work back into taf sites late
in period but more likely Wednesday night.
in...beach hazards statement until 11 PM CDT this evening for inz003.
Michigan...Beach hazards statement until midnight EDT tonight for miz077.
Lm...Small Craft Advisory until midnight EDT tonight for lmz043-046.
Visit US at www.Weather.Gov/iwx (all lower case)
Follow US on facebook...twitter...and youtube at: