Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 301522

Area Forecast Discussion
National Weather Service Northern Indiana
1122 AM EDT Thu Mar 30 2017

Issued at 453 AM EDT Thu Mar 30 2017

Showers and thunderstorms are expected in the area today and
tonight as a low pressure system approaches from the Southern
Plains. There is a risk of severe storms, especially across
southern portions of the area this afternoon and this evening.
Showers will taper off from west to east Friday as the low
departs. High pressure will build into the Midwest Saturday
providing fair weather.


Issued at 1122 AM EDT Thu Mar 30 2017

Forecast for this aftn/eve on track with some concern for
isolated severe storms mainly southeast of US 24 between 20-02z as
sfc warm front draped across southern IL-southwest IN mixes north
to near our far southern zones late aftn/eve. 0-3km helicity of
300-500 m2/s2 and deep layer shear in excess of 40 knots favorable
near this boundary by this time, though sfc/mixed layer buoyancy
remains uncertain with latest NAM CAPE progs likely a little too
aggressive with MLCAPE`s in excess of 1000 j/kg. Favor the more
stable HRRR progs given extensive cloud cover and lower sfc
dewpoints (mid-upper 50s) when compared to the NAM. As a result
expect this to be a rather messy convective event southeast of US
24. With that said cannot rule out an isolated severe storm with
brief tornado, small hail, and damaging winds the primary threats
if any low centroid/line segments organize. Cool and occasionally
wet with embedded thunder elsewhere.


.SHORT TERM...(Today through Friday)
Issued at 453 AM EDT Thu Mar 30 2017

A vigorous upper level low was centered over eastern Kansas early
this morning. This system will move east and track north of the
Ohio Valley Friday. Several factors appear to be coming together
for the potential for severe storms over the forecast area today
and early tonight. A warm front will move north today and should
be close to Highway 30 by late afternoon. A cool east flow north
of the front off Lake Erie will accentuate the front. Increasing
instability combined with increasing low level shear will enhance
the chances for strong to severe storms including large hail,
damaging winds and isolated tornadoes along and south of the
front. The best chances for severe storms is from mid afternoon
through this evening. Precipitable water values are still expected
to approach climatological maxes of 1.25 for this time of year.
Rainfall amounts by the time rain ends Friday should range
between 0.75 inches over northwest Ohio to 1.25 inches over
northwest Indiana. Lingering rain will diminish Friday as the low
moves east and high pressure builds across the area.


.LONG TERM...(Friday night through Wednesday)
Issued at 453 AM EDT Thu Mar 30 2017

Two more rounds of rain are on the horizon as more upper level
systems move across the area next week. Rain is expected to
develop by late Sunday and continue into Monday with the arrival
of next system. After a break Tuesday, more rain is likely
Wednesday. Thermal profiles favor all rain.


.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 615 AM EDT Thu Mar 30 2017

Low pressure over MO expected to lift slowly ne into nw OH by 12z
Fri. Initial cluster of showers and tstms in low level theta-e
advection regime were lifting ne of nrn IN attm but broad isent
lift and upr level divergence along with now moist airmass in
place should keep at least sct shra/ts going through the day and
into this eve. Brief mvfr/ifr conditions likely with heavier
shra/ts and there is also a risk of hail and gusty winds accompanying
the storms, mainly this aftn/eve. Otrws, flight conditions
expected to grdly lower to mvfr/ifr at SBN today while FWA remains
predominantly vfr as the low tracks ne between the two terminals.
As the low passes tonight the lower flight conditions should
advect se into FWA.


LM...Small Craft Advisory until 4 PM EDT this afternoon for LMZ043-



SHORT TERM...Skipper
LONG TERM...Skipper

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