Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 260737

Area Forecast Discussion
National Weather Service Northern Indiana
337 AM EDT Wed Apr 26 2017

Issued at 311 AM EDT Wed Apr 26 2017

Low pressure will lift northeast from the southern Plains today to
the western Great Lakes tonight likely causing showers and
possibly thunderstorms to spread into the area by late tonight.
Temperatures will remain mild ahead of this system but cool off in
its wake on Thursday. Another strong and rather slow moving low
is expected to take a similar track over the weekend, causing
showers and possibly thunderstorms in our area. Locally heavy
rainfall is possibly in this timeframe. Cooler and drier weather
will follow this system early next week as high pressure builds in
by Tuesday.


.SHORT TERM...(Today through Thursday)
Issued at 311 AM EDT Wed Apr 26 2017

Cdfnt over the mid MS River valley will be slow to move east today
as cyclogenesis occurs along it over MO/IL in response to strong
shrtwv rounding base of upr trof over the srn plains. Subtle warm
front to east of the dvlpg low will lift north across wrn portion
of the cwa this aftn/eve and may provide sufficient forcing along
with wk instability in place for a few showers/tstms. Otrws
should be a warm/breezy day with highs ranging from the mid 70s
west to the lower 80s east where more sunshine is expected.
Better chance of showers/tstms late tonight and Thu morning as
strong cdfnt associated with this system moves east across the
area. Deep layer shear favorable for svr storms but wk
instability limiting factor. Cyclonic flow associated with deep
upr grtlks low will provide much cooler temps behind the cold
front Thu with most of the area reaching high temps in the morning
while mostly cloudy skies and brisk winds persist through the day.


.LONG TERM...(Thursday night through Tuesday)
Issued at 311 AM EDT Wed Apr 26 2017

Wk ridging will move across the area Thu night providing fair wx
with seasonably cool temps. Rain chances return Fri/Fri night as
front lifts back north in response to another shrtwv/sfc low
shearing out as it moves ne from the central plains into the
Grtlks. Upr trof over the Rockies finally lifts out over the
weekend with resultant cyclogenesis over the srn plains followed
by deep low movg ne into the upr grtlks. Strong forcing and deep
flow of moisture from the gulf (precip water >1.5") along with
relatively slow system movement suggests potential for locally
heavy rainfall, though a limiting factor in this regard may be
deep convection along systems cold front in more unstable airmass
to our south disrupting forcing/moisture transport as the cdfnt
moves through. Limiting factor for svr once again appears to be wk
instability with another strong flow/high shear environment
expected. Windy/Cool conditions Monday as cold air wraps around
the deep low movg into the upr grtlks. Strong cyclonic flow and
wrap around moisture may allow for some light showers to persist.
Dry wx expected by Tue with some moderation in temps as high
pressure ridge builds in.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 218 AM EDT Wed Apr 26 2017

VFR conditions expected through the forecast period. A strong
weather system to the west will be slow to move east. There is an
outside chance for a shower or storm very late in the period at
SBN, but for now opted to keep the TAFs dry and VFR.


LM...Small Craft Advisory until 5 PM EDT this afternoon for LMZ043-




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