Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 190634

Area Forecast Discussion
National Weather Service Northern Indiana
234 AM EDT Fri May 19 2017

Issued at 230 AM EDT Fri May 19 2017

A few lingering rain showers are possible south of Route 24
through 4 AM this morning. Otherwise, noticeably cooler air will
then filter in through this morning behind a cold front. Highs
today will run about 15 to 20 degrees colder than yesterday. Rain
chances return for the weekend as the frontal band lifts back
northward, with the best chances Saturday afternoon into Saturday


.SHORT TERM...(This Evening through Friday)
Issued at 356 PM EDT Thu May 18 2017

Corridor of 1000-1500 j/kg along with effective deep layer shear
of 30 knots with convection starting to fire amid prior robust
roll/cu streets. Lack of significant severe parameters, low level
forcing stabilizing boundary layer beyond 00 UTC and overall mid
level height rises. Upstream cold front attendant to dampening
yoop mid level vortex to bring substantially cooler albeit shallow
boundary layer south of cwa by daybreak Friday. Ensuing shower
chances on flank of return/elevated warm air advection
wing/especially southwest third to half cwa but not expected to be
widespread/robust until much later in weekend.


.LONG TERM...(Friday Night through Thursday)
Issued at 356 PM EDT Thu May 18 2017

As greater mid/upper level support lifts out of central Rockies
and into Upper Midwest/Mississippi Valley expect more fervor to
moisture return/destabilization for greater coverage of shra/tsra
Sat afternoon into Sat night. Drier/cooler behind second cold
frontal passage to start early next week followed by a strong
northern stream wave to redig cyclone farther south over southern
portions of Upper Great Lakes into Lower Ohio Valley. A bit more
selective with thunder chances, relegated to lesser slight chances
Tuesday afternoon with lesser low level lapse rates thereafter in
deeply cool/stacked system.


.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 230 AM EDT Fri May 19 2017

Sfc cold front has shifted south of terminals with focus for
additional shower/thunderstorm activity expected to remain across
central Indiana. MVFR deck has slowly been creeping southward
across extreme northwest/north central Indiana affecting KSBN
area, but cigs should remain above fuel alternate criteria over
the next several hours. Low confidence at this time in terms of
MVFR cigs reaching KFWA overnight and will keep cigs at VFR
levels. Frontal boundary to stall south of the area today which
will result in establishment of east winds and likely persistence
of stratocu across the area. With low confidence in MVFR cigs,
will keep stratocu at VFR bases through this forecast valid
period. Better chance of showers and embedded storms will begin to
increase again just after this forecast valid period as upper
ridge shifts off to the east, and next larger scale upper trough
emerges from the Rockies.


LM...Small Craft Advisory until 11 AM EDT this morning for LMZ043-046.



LONG TERM...Murphy

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