Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 191809

Area Forecast Discussion
National Weather Service Northern Indiana
209 PM EDT Fri Apr 19 2019

Issued at 1042 AM EDT Fri Apr 19 2019

Some showers will move across the area into this afternoon before
one last round of widespread rainfall arrives tonight and
persists into Saturday. Additional rainfall amounts through
Saturday afternoon will range from less than one quarter of an
inch across far northwest Indiana and extreme southwest Lower
Michigan to around an inch along and east of the Interstate 69
corridor. Otherwise, cool and windy conditions are expected today
with high temperatures only reaching the mid and upper 40s. Below
normal temperatures will continue into Saturday before high
temperatures warm back into the 60s and lower 70s for Sunday under
mostly sunny skies.


Issued at 1042 AM EDT Fri Apr 19 2019

Quick update went out earlier to lower pops across the area,
removing any likely pops and trying to dry things out across the

Radar trends have continued down over the past several hours as
best moisture feed has been shunted east and dry air entraining
aloft as shown on water vapor loop satellite. Hi res models by in
large agree with this downward trend although still showing a bit
more coverage than actually occurring. Have left forecast intact
for this evening with expected uptick in precip as upper low
continues to deepen with deformation zone expected to take shape
and rotate into the forecast area. Have left temps alone for now,
but rise is slower than forecasted and wondering if CAA may be
strong enough to limit much in the way of further rises.


.SHORT TERM...(Today and Tonight)
Issued at 350 AM EDT Fri Apr 19 2019

Hydrologic concerns will continue to be the primary focus of the
short term, with a few additional rounds of rainfall through late
Saturday afternoon.

Deepening frontal wave this morning across the Ohio Valley has
resulted in increasing coverage of rain with low level reflection
of this frontal wave aiding in deep frontogenetic response. This
forcing and deeper frontogenesis response should quickly translate
east/northeast across the eastern Great Lakes later this morning
resulting in eventual diminishing coverage/intensity of rain
showers late morning-early afternoon. Rain shield is expected to
make slight additional north/northwest progress across NW
Indiana/SW Lower Michigan over next hour or two, but precip
amounts will be quite light across these locations. Elsewhere,
hourly rainfall rates between 0.05-0.15 inches per hour will be
possible through shortly after daybreak.

Below normal temperatures will be in place today as northerly flow
continues to ramp up this morning in response to slow northward
progression of deepening Ohio Valley cyclone. North gusts to 25 to
35 mph will be possible today, and combination of neutral
temperature advection and abundant cloud cover will not allow for
much diurnal range today with afternoon high temps in the mid to
possibly upper 40s. Gusty north winds will persist into this
evening, but gradual filling of sfc low overnight will lead to
diminishing winds during the overnight hours.

Regarding precip chances tonight...a 110 knot upper jet streak
digging across the southern Plains this morning will rotate through
parent upper low and result in eventual northeast progression of
upper low center into Saturday morning. Track of this system will
continue to provide favorable deformation forcing across
especially central/eastern portions of the forecast area later
tonight into at least early afternoon Saturday. TROWAL feature
wrapping into this system may also enhanced precip rates with this
deformation forcing, with additional rainfall amounts tonight
into Saturday of 0.50 to 1 inch a possibility.

Heavier rainfall amounts did not quite materialize yesterday, and
concerns for significant areal flooding appear to have diminished
somewhat. Will continue to mention potential of some
minor river/lowland flooding in this mornings Hazardous Weather


.LONG TERM...(Saturday through Thursday)
Issued at 350 AM EDT Fri Apr 19 2019

Deformation rain will come to an end Saturday evening with the
remainder of the weekend looking quiet as conditions moderate
for Sunday as upper ridging builds into the region in advance
of next western CONUS trough.

A lead disturbance kicking out of broad western CONUS trough
and a more progressive northern stream along US/Canadian border
will allow next frontal passage in the late Monday/early Tuesday
timeframe with a chance of showers and storms Monday/Monday night
before front settles south of the area again on Tuesday. Monday
should feature the warmest conditions of the forecast with highs
in the low to mid 70s.

Predictability diminishes toward the middle of next week in
regards to evolution of southwest CONUS cutoff low. With
increasing indications of stronger forcing remaining south of the
area, and low predictability, will keep latter periods dry at this


.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 156 PM EDT Fri Apr 19 2019

Strong/deep north-northeast flow to drive drier air into northwest
Indiana/KSBN through the period with transition to VFR anticipated
by evening. In contrast richer bulk moisture through northeast
Indiana with primarily low end MVFR for fueling/alternate
dominant conditions. Attempted to focus on stronger band of
rainfall/tempo IFR conditions towards daybreak into mid Saturday
morning into KFWA as upper low, currently over northern
Mississippi lifts north into Middle Ohio Valley. Ramp of low level
winds also continues to be significant enough in speed for LLWS
mention late night/early Saturday morning.


LM...Gale Warning until 9 PM EDT this evening for LMZ043-046.



SHORT TERM...Marsili
LONG TERM...Marsili

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