Special Weather Statement, NWS Northern Indiana

Area Forecast Discussion
National Weather Service Northern Indiana
751 PM EDT Sun Oct 24 2021

.SYNOPSIS...
Issued at 322 PM EDT Sun Oct 24 2021

Widespread rain is anticipated tonight with an additional 1 to 2
inches for most areas and isolated amounts up to 3 inches possible.
This may cause flooding in low areas and along small creeks and
streams. Always remember turn around...don't drown when encountering
water covered roads. Rain ends Monday with breezy conditions
expected. The next chance of rain will not arrive until the end of
the week.

&&

.SHORT TERM...(This Evening through Monday)
Issued at 322 PM EDT Sun Oct 24 2021

Rain blossomed across the area earlier today as expected given
initial surge of deep isentropic ascent, most notable around 295-
300K in right entrance region of 140+ kt upper level jet. However
one limiting factor to coverage and intensity of rain so far today
(especially right now) has been active convection along surface warm
front over central IN preventing better northward moisture
advection. That will change by this evening though and still expect
peak of the event to be 00-06Z. Excellent mid/upper dynamics noted
during this time as nose of cyclonically curved 100 kt upper jet
moves into the region and couples with zonal jet to our NE. Lower
level (925-850mb) deformation/fgen really lights up in our CWA as
surface warm front inches northward. Large-scale ascent is further
aided by strong midlevel CVA later tonight. A short period of heavy
rain is expected for portions of our central and NW CWA late this
evening given strong fgen beneath at least a neutral (more likely
weakly unstable) profile aloft. Could easily see a quick 1-2" in a 3-
hour period with this setup. Fortunately it remains progressive with
a narrow window for heaviest precip rates. Biggest question remains
where exactly this corridor of highest rain sets up. Latest NAM and
GFS have shifted slightly further NW while most of the hi-res
guidance remains focused more in our central CWA. Still leaning
toward central CWA with only minor changes to latest storm-total
amounts of around 2-3 inches (slightly lower due to less rain this
afternoon). Confidence is not high for heavy rain/flooding in our MI
counties but enough concern to expand the watch (especially in light
of latest river forecasts which show a couple of our MI sites going
into minor flood). Around 2 inches anticipated in our north with
less in our far SE. Heavy rain ends quickly Mon AM as best forcing
and moisture convergence shift rapidly NE while narrow midlevel
dry slot is anticipated around 12Z. Vort max moves overhead later
in the day though and midlevel deformation will maintain some
showers into Mon evening. This will not add much to our QPF
though.

Still a very small threat for severe weather this evening in our far
SW zones. Most guidance shows surface warm front falling just short
of our southern CWA border this evening and most forecast soundings
indicate a strong stable layer below 900mb in even our far SW areas
that will be difficult to penetrate. MUCAPE is supportive of thunder
and perhaps some pea-sized hail but not large hail. Will certainly
keep a close eye on this area given proximity to warm front and
associated very high shear/helicity values but threat appears low at
this point.

Finally, gusty winds still anticipated Monday into Monday evening
given tight gradient and modest mixing in wake of departing low.
Forecast soundings/momentum transfer suggest peak gusts topping out
around 35 mph though and wind advisory does not appear likely at
this time. Some 40 kt gusts may be possible along the lakeshore
given very warm water temps/increased mixing/decreased friction but
flow remains NE most of the day and gradient weakens by the time
wind back north. Will therefore hold off on an advisory at this time.

&&

.LONG TERM...(Monday Night through Sunday)
Issued at 322 PM EDT Sun Oct 24 2021

Very few changes to long-term given short-term hazards. Primarily
dry conditions anticipated Monday night through Wednesday. Some lake
effect showers possible Monday night but NNE trajectories would keep
best chances just to our west. Very good radiational cooling potential
Tue night. Leaned on the cooler side of guidance with mid 30s. Patchy
frost is likely, especially for our northern zones.

Our classic late Oct upper low arrives on Thu with the next chance
of widespread rain. Ingredients for high QPF are not nearly as
favorable with this system but prolonged period of widespread,
light rain could cause minor flooding issues to linger on some of
our slower rivers. Clouds and showers persist into Sat but highs
remain around average with lows slightly above average.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 739 PM EDT Sun Oct 24 2021

Much warmer air was to the south in the vicinity of a warm front
near the Ohio River. Warmer air had made its way as far north as
HUF. A band of elevated convection had developed north of IND and
with bring a period of heavy rain showers and possible thunder to
the terminals. Farther to the west, intense convection was moving
east over northern IL. The leading edge of the convection was
about to reach the Indiana border near Lansing/IGQ. Have included
TEMPO groups at both the SBN and FWA terminal to account for this
activity over the next few to several hours. IFR ceilings should
persist for most of the duration of the TAFs, although some
improvement is possible late Monday.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Flood Watch through Monday morning for INZ003>009-012>018-020-
     022>026.

MI...Flood Watch through Monday morning for MIZ077>081.

OH...Flood Watch through Monday morning for OHZ001-002-004-005-015-
     016.

LM...Gale Warning until 8 PM EDT Monday for LMZ043-046.

&&

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...AGD
AVIATION...Skipper

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Hazardous Weather Outlook
National Weather Service Northern Indiana
322 PM EDT Sun Oct 24 2021

INZ003>009-012>018-020-022>026-MIZ077>081-OHZ001-002-004-005-015-016-
251930-
La Porte-St. Joseph-Elkhart-Lagrange-Steuben-Noble-De Kalb-Starke-
Pulaski-Marshall-Fulton-Kosciusko-Whitley-Allen-White-Cass-Miami-
Wabash-Huntington-Wells-Berrien-Branch-Hillsdale-Williams-Defiance-
Henry-Paulding-Putnam-
322 PM EDT Sun Oct 24 2021 /222 PM CDT Sun Oct 24 2021/

...FLOOD WATCH IN EFFECT THROUGH MONDAY MORNING...

This Hazardous Weather Outlook is for northern Indiana, southwest
Michigan and northwest Ohio.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

Thunderstorms are possible tonight but severe weather is not expected
at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

INZ027-032>034-OHZ024-025-251930-
Adams-Grant-Blackford-Jay-Van Wert-Allen-
322 PM EDT Sun Oct 24 2021

This Hazardous Weather Outlook is for northern Indiana and
northwest Ohio.

.DAY ONE...This afternoon and tonight.

Widespread showers and a few embedded thunderstorms are expected
through tonight. Areas of moderate rainfall may cause rivers,
streams and creeks to rise.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Showers will continue into Monday. Rivers, streams and creeks may be
running high.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

LMZ043-046-251930-
New Buffalo MI to St Joseph MI-Michigan City IN to New Buffalo MI-
322 PM EDT Sun Oct 24 2021

...GALE WARNING IN EFFECT FROM 7 PM THIS EVENING TO 8 PM EDT
MONDAY...

This Hazardous Weather Outlook is for the nearshore waters of
southeastern Lake Michigan.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Gale Warning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Gale Warning.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Northern Indiana
819 PM EDT Sun Oct 24 2021

INZ003-012-013-020-250100-
La Porte IN-White IN-Starke IN-Pulaski IN-
819 PM EDT Sun Oct 24 2021

...Strong thunderstorms will impact portions of White, Pulaski,
Starke and La Porte Counties through 900 PM EDT/800 PM CDT/...

At 818 PM EDT/718 PM CDT/, Doppler radar was tracking strong
thunderstorms along a line extending from Lincoln Hills to near Fair
Oaks to near Fowler. Movement was east at 50 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Strong thunderstorms will be near...
  Wanatah around 830 PM EDT.
  Westville, Francesville and Medaryville around 835 PM EDT.

Other locations in the path of these storms include Wolcott, North
Judson, Kingsford Heights, Brookston, Monticello and Winamac.

This includes the following highways...
 Interstate 65 between mile markers 185 and 198.
 Interstate 80 in Indiana between mile markers 38 and 61.
 Interstate 94 in Indiana between mile markers 33 and 45.
 Interstate 94 in Michigan near mile marker 0.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4084 8710 4084 8699 4091 8699 4091 8693
      4171 8693 4176 8682 4176 8652 4165 8653
      4165 8650 4074 8658 4073 8676 4068 8674
      4066 8678 4056 8677 4056 8709
TIME...MOT...LOC 0018Z 263DEG 43KT 4148 8713 4107 8718 4067 8736

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

JAL