Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 241756

Area Forecast Discussion
National Weather Service Northern Indiana
156 PM EDT Wed May 24 2017

Issued at 151 PM EDT Wed May 24 2017

Rain showers with isolated thunderstorms are expected late this
afternoon and overnight. Some areas could see up to 1 inch of
rain, which could lead to flooding in already saturated
agricultural areas and along rivers. Northerly winds will kick up
3 to 5 ft waves and dangerous currents on Lake Michigan by late
afternoon, so people visiting the beaches should stay out of the
water. There is a chance for rain showers Thursday, Saturday
night, and Sunday. Thunderstorms are possible Saturday night into
Sunday. Severe weather is not expected. Highs will be in the upper
60`s and 70`s, coolest near Lake Michigan.


Issued at 1214 PM EDT Wed May 24 2017

Increasing coverage/intensity of showers/storms can be expected
mid afternoon through early evening as forcing and deep moisture
transport (associated with shortwave and strong left exit jet
support) pivot northeast into the Ohio Valley on the eastern
fringe of an unseasonably deep upper low dropping southeast
through Missouri. Locally heavy rainfall and better chances for
thunderstorms will be confined to our ne IN/nw OH counties where
low level front strengthens and nearly 1000 j/kg of SBCAPE
resides. Lacking shear/flow and meager lapse rates should preclude
much of a severe threat, but can`t rule out an isolated weak
tornado near boundary in ne IN/nw OH this afternoon. The bigger
threat will be the potential for localized heavy rain/flooding,
especially near the I-69 corridor in ne IN.


.SHORT TERM...(Today through Thursday)
Issued at 416 AM EDT Wed May 24 2017

An upper low was over Iowa early this morning. This low will drop
south and then curve north and bring a round of showers and a few
storms to the area today and tonight. Prefer the ECMWF that
appears to maintain better consistency than the other models and
also supports the potential for rainfall amounts over an inch by
Thursday morning. Severe storms are not expected given clouds and
limited instability. However, localized flooding is possible
especially where any bands of heavier rain set up. Rain will
diminish late tonight and Thursday as the system accelerates east.


.LONG TERM...(Thursday night through Tuesday)
Issued at 416 AM EDT Wed May 24 2017

The upper level flow will become more west with moderating
temperatures by Friday. Highs should be in the 70s to around 80
from Friday through Monday. There is still some uncertainty
concerning the timing of showers and storms during this period.
Rejected the model blend given an apparent wet bias and
unrealistic shower/storm chances most periods. Limited forecast
showers and storms to Friday night,Saturday night and Sunday given
the timing of the next system. Most of the holiday weekend will
be dry with temperatures near normal.


.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 151 PM EDT Wed May 24 2017

VFR conditions for the first part of the TAF Period, then a
gradual decline to MVFR/IFR as precipitation moves in. Expect
showers and perhaps a few thunderstorms at KSBN this afternoon
before more substantial rain moves in after 21Z. Did not feel
confident including VCTS in the TAF yet...but will monitor closely
as things develop. Otherwise, expect a period of more steady rain
this evening and continuing into the overnight hours.

Kept things low-end MVFR overnight for now at KSBN, but will need
to watch for ceiling heights just below 1000 feet late tonight
into Thu morning. Otherwise, the broader shield of precipitation
is lifting northward as of 18Z, and should impact KFWA no later
than about 19Z. A few thunderstorms have already been observed far
to the north and east of the airport, so have included a mention
in the TAFS. With more substantial moisture arriving, expect
conditions will deteriorate to IFR shortly after midnight.
Visibility in the more moderate rain to our south has ranged from
2-4SM, so have KFWA dropping to around 3SM. Scattered shower
activity will be possible later Thu AM, and will continue through
Thu afternoon with a gradual improvement in ceilings/visibility.


Issued at 1150 AM EDT Wed May 24 2017

Waves of 3 to 4 feet will approach the shore at a 60 to 90 degree
angle by late this afternoon as they build to around 5 feet. Wave
periods will gradually lengthen to 5 to 6 seconds. These
conditions are supportive of strong rip current development within
sandbars, and strong structural currents near piers and
breakwalls. Furthermore, water temperatures are in the 50`s, which
can lead to hypothermia. People visiting the beaches of Lake
Michigan today should stay out of the water. Issued a small craft
advisory and a beach hazards statement for the dangerous


IN...Beach Hazards Statement through Thursday morning for INZ003.

MI...Beach Hazards Statement through Thursday morning for MIZ077.

LM...Small Craft Advisory from 5 PM this afternoon to noon EDT
     Thursday for LMZ043-046.



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

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