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Area forecast discussion 
National Weather Service northern Indiana
355 am EDT Friday Sep 19 2014

issued at 355 am EDT Friday Sep 19 2014

High pressure will begin to retreat eastward in advance of a
developing low pressure system across the northern plains. Dry
conditions will persist into Saturday afternoon with moderating
temperatures expected. Highs this afternoon will reach into the low to
middle 70s.


Short term...(today and tonight)
issued at 355 am EDT Friday Sep 19 2014

Surface ridge centered over southeastern Ontario will give way to progressive SW
trough and attendant frontal system by Sat. Increasing ll warm air advection especially late
this afternoon will give a boost to temperatures especially western/southern zones vs yesterday. Much
warmer especially western half in proximity to stronger southwesterly gradient follow and
likely encroachment of high cloud shield. Otrws dry as western bound of ll
anticyclone slw to moisten along west/veered ll wrly follow suggesting
general weak subsident follow will persist into Sat am.


Long term...(saturday through thursday)
issued at 355 am EDT Friday Sep 19 2014

Potentially active Sat afternoon/evening period in store for at least northwest
parts of the area as increasingly favorable looking dynamics appear
to be coming into play.

Tough forecast in terms of how to handle chances for showers/storms
as models have all backed off on precipitation chances (now generally chance
to a few spots showing likely) Sat afternoon/evening as speed and depth of
moisture return remains in question. With low to middle 60 dewpoints not that
far away given increasing flow which will setup over the next 24 is plausible for similar values to advect in right ahead
of the cold front during peak heating. 0-3 km shear on BUFKIT
soundings all point towards anywhere from 40 to 50 kts of mainly
unidirectional shear. This would set the stage for a risk of
strong-severe storms if timing and moisture align just right. Models vary
greatly on these points ranging from a few hundred j/kg of surface
based cape to pushing 2000 j/kg. Storm Prediction Center day 2 outlook has placed the northwest
quarter or so of the area in a slight risk for damaging winds. While
we can't disagree...this will be highly conditional on temperatures
climbing into the upper 70s to lower 80s and dewpoints into at least
the lower 60s. Risk diminishes rapidly with southeast progression assuming
no organized cold pool were to establish. Chances Sat am looking
rather poor (if this did unfold then chance for severe would be
diminished given possible convective debris). Have confined slight chance
probability of precipitation to far northwest. Otherwise have left Sat afternoon into Sat night alone
despite above mentioned issues with guidance.

Some lingering showers may exist in the southeast Sunday morning...but
should quickly depart with seasonable afternoon highs in the lower
to middle 70s. Main shot of colder air will arrive Sunday night with
surface high pressure settling over the lower Great Lakes into next
week. Could be a stray shower with the trough passage but overall
lift and remaining moisture looks rather bleak.

Temperatures will begin to moderate back towards normal levels by
middle week as the high shifts east of the area and then settles in
over the eastern states. This should allow for a quiet
period...likely extending into the weekend.


Aviation...(for the 06z tafs through 06z Friday night)
issued at 352 am EDT Friday Sep 19 2014

VFR conds through the period. However eastward retreat of Stout surface anticyclone
in response to developing northern plains surface frontal wave. Expect surface gradient to
ramp this afternoon vicinity ksbn west/surface gusts to 15kts.


Iwx watches/warnings/advisories...
Lm...Small Craft Advisory from 11 PM this evening to 5 PM EDT
Saturday for lmz043-046.



short term...T
long term...Fisher

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