Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 210448

Area Forecast Discussion
National Weather Service Northern Indiana
1248 AM EDT Fri Apr 21 2017

Issued at 1209 AM EDT Fri Apr 21 2017

Cooler and dry conditions are just ahead through this weekend
over the Upper Great Lakes Region as high pressure gradually
builds into the region. Highs will be in the 50s today and
Saturday, and then the 60s Sunday. Patchy frost is possible over
mainly Lower Michigan Friday and Saturday nights.


Issued at 619 PM EDT Thu Apr 20 2017

Severe threat slowly diminishing with watch being cleared behind
the cold front as it progresses east.

A few severe storms developed ahead of the front across Putnam
county, dropping hail to at least the size of half dollars.
Along the cold front itself, line of storms persists but has
remained below severe levels for at least the past hour or so.
Mixed layer CAPE on the downward trends as this area has been
worked over a fair amount. Marginal threat ahead of the front
warrants holding onto the watch for now, but if downward trend
continues watch may be dropped early.


.SHORT TERM...(This Evening through Friday)
Issued at 329 PM EDT Thu Apr 20 2017

Thunderstorms dotting the forecast area generally east of a
Logansport to Coldwater line with greatest concentration along the
pre-frontal trough now moving into NW Ohio. Storms have struggled
to organize with mainly pea size hail reported and pockets of
40 to 55 (48 kt gusts at Ft Wayne). As the first area departed,
sufficient recovery occurred to allow for a narrow area of sct
storms to develop from Ctrl Illinois into portions of N Indiana.
Actual cold front not too far behind this second line resulting in
a rapid end to all storm chances through the remainder of the
afternoon. Will likely clear watch as back edge of the storms
exits impacted areas.

Vis satellite showing extensive stratocu field to slowly work
east. Could be a period of clearing immediately behind the front
before it arrives. Have increased clouds cover to mostly cloudy
with slower trends on clearing into Friday. Highs Friday will be a
good 15 to 20 degrees cooler across the area with mid 40s NW to
upper 50s SE.


.LONG TERM...(Friday Night through Thursday)
Issued at 329 PM EDT Thu Apr 20 2017

Deep Hudson Bay closed low will remain in place into early next week
before slowly shearing apart and ejecting NE. Influence of the low
will keep moisture and warmer temperatures well suppressed as
longwave trough rounds the base of the trough. Period of somewhat
below normal temperatures will dominate with a shot at some frost
especially Sunday morning. Moderation in temps will occur as
Great Lakes trough exits stage right and heights increase ahead of
the next wave dropping out the Plains by Monday night.

The arrival of the Plains wave will bring a chance for showers to
the area, but not until closer to Wednesday as first embedded wave
shoots to the west of the region before main wave edges east. No
more than chc pops at this point with temperature soaring back above
normal into the 70s.


.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1156 PM EDT Thu Apr 20 2017

A large area of post-frontal clouds of an MVFR and VFR mix
associated with a low pressure area near far northern Lower
Michigan will spread across the terminals today. Although deep
layer subsidence will be increasing, much clearing is not likely
until late in the day as moisture remains trapped under the base
of a subsidence inversion. Skies should become partly cloudy this
evening with winds becoming light as winds decouple.


LM...Small Craft Advisory until 11 PM EDT Friday for LMZ043-046.



LONG TERM...Fisher

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