Special Weather Statement, NWS Indianapolis, IN

Area Forecast Discussion
National Weather Service Indianapolis IN
301 AM EDT Thu Jul 8 2021

.Short Term...(Today through Friday)
Issued at 301 AM EDT Thu Jul 8 2021

Scattered convection was across mainly the far northern forecast
area, stretching back into central Illinois early this morning.
Isolated convection was across the far southwestern forecast area. A
surface cold front extended from lower Michigan southwest to north
of St. Louis. An upper trough was just west of the area.

Based on recent trends, believe that at least isolated convection
will continue through the remainder of the predawn hours, especially
with the upper trough and front nearby. Will continue some PoPs
before 12Z.

After 12Z, the left exit region of an upper jet will be near the
northern forecast area. This will likely aid in the production of
some convection by mid to late morning there. Later during the day,
as the cold front moves through the area, it will interact with
unstable air to produce scattered to numerous showers and
thunderstorms. Overall, will end up going at least likely PoPs most
areas at some point during the day.

There is enough shear around to perhaps get some isolated severe
storms this afternoon, mainly across the eastern and southern
forecast area ahead of the front.

The front will be exiting the area this evening, so will just keep
some low PoPs in the east during the evening hours.

Surface high pressure will build into the area overnight into Friday
morning, and this will provide dry and cooler conditions. During the
afternoon, an upper disturbance in northwest flow aloft will
approach the area. Some lift will occur aloft with this feature by
late afternoon. However, the surface high will still have influence
over much of central Indiana, keeping the low levels dry.

Thus, while some sprinkles may be possible in the far west later on
Friday, feel that mentioning PoPs will be overdone. Will go with a
dry forecast.

&&

.Long Term...(Friday night through Wednesday)
Issued at 301 AM EDT Thu Jul 8 2021

The long term period looks to be active, beginning with the arrival
of leading shortwave impulses ahead of a strengthening low early in
the weekend. This low will close off somewhere in the region, likely
to our west per the general consensus of deterministic guidance, and
lead to multiple potential rounds of showers and thunderstorms
throughout the long term period.

While a marginal severe threat would not be out of the question
given at times modest deep layer shear values, the more substantial
concern will be hydrologic with deeply saturated/pseudotropical
profiles (featuring deep but thin instability profiles)
and precipitable water values continuing to be advertised at 1.8 to
2 inches, which approaches climatological maximum for the time of
year. This, along with wet antecedent conditions means heavy rain
from thunderstorms, particularly if occurring in multiple rounds,
will have little trouble causing at least nuisance flooding issues,
if not flash flooding and renewed river flooding. OHRFC river flood
ensembles indicate at least a 30 percent chance of renewed minor
flooding along portions of the main stem rivers, particularly in
southwest Indiana where river flooding has been an issue for some
time now, and just recently ended.

The closed upper low looks to lift out of the area by mid week next
week, although additional disturbances in the weakly cyclonic flow
will continue to merit precip chances through the end of the period.

Given the overall pattern, temperatures should be at least a bit
below normal, particularly early in the long term period, and the
blend has handled this quite well.

&&

.Aviation...(06Z TAF Issuance)
Issued at 115 AM EDT Thu Jul 8 2021

IMPACTS:
- MVFR ceilings likely after 09z this morning
- Scattered convection after 15Z, with MVFR to IFR within
thunderstorms
- Sustained winds generally 10kt or less...except in/around storms
- Gradual wind shift following frontal passage

DISCUSSION: Isolated convection is occurring around central Indiana.
With most of it east and north of KIND, only KLAF will carry VCSH
overnight Cloud cover is expected to fill early tomorrow morning
ahead of a upper level wave leading to MVFR ceilings. Rain and
thunderstorms chances will increase for early tomorrow afternoon
with best chances for KIND between 18Z and 21Z as a weak cold front
passes through. A wind shift is likely following the frontal passage
tomorrow from W-SW to N-NW. Expect mainly MVFR in the early
afternoon with improving conditions in the evening after frontal
passage.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

Short Term...50
Long Term...Nield
Aviation...Updike

Hazardous Weather Outlook
National Weather Service Indianapolis IN
344 AM EDT Thu Jul 8 2021

INZ021-028>031-035>049-051>057-060>065-067>072-090745-
Carroll-Warren-Tippecanoe-Clinton-Howard-Fountain-Montgomery-Boone-
Tipton-Hamilton-Madison-Delaware-Randolph-Vermillion-Parke-Putnam-
Hendricks-Marion-Hancock-Henry-Vigo-Clay-Owen-Morgan-Johnson-Shelby-
Rush-Sullivan-Greene-Monroe-Brown-Bartholomew-Decatur-Knox-Daviess-
Martin-Lawrence-Jackson-Jennings-
Including the cities of Delphi, Flora, Williamsport, West Lebanon,
Lafayette, West Lafayette, Frankfort, Kokomo, Attica, Covington,
Veedersburg, Crawfordsville, Lebanon, Zionsville, Tipton, Fishers,
Carmel, Noblesville, Anderson, Muncie, Winchester, Clinton, Newport,
Rockville, Greencastle, Plainfield, Brownsburg, Danville,
Indianapolis, Greenfield, New Castle, Terre Haute, Brazil,
Clay City, Spencer, Martinsville, Mooresville, Greenwood, Franklin,
Shelbyville, Rushville, Sullivan, Linton, Bloomfield, Bloomington,
Nashville, Columbus, Greensburg, Vincennes, Washington, Loogootee,
Shoals, Bedford, Mitchell, Seymour, Brownstown, and North Vernon
344 AM EDT Thu Jul 8 2021

This hazardous weather outlook is for central Indiana.

.DAY ONE...Today and Tonight.

Scattered to numerous showers and thunderstorms will be around
through the day today, ending all areas this evening. Isolated severe
storms with damaging winds are possible, mainly this afternoon and
early evening.

Any storm will be capable of producing gusty winds, small hail, heavy
rain, and lightning.

Storm motion will generally be to the east at around 25 mph.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Thunderstorms are possible for much of the time from Friday night
through Wednesday. Any storm can produce cloud to ground lightning,
gusty winds and locally heavy rain.

Repeated rounds of storms with heavy rain could lead to flooding
this weekend into early next week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation cannot be ruled out this afternoon and early
evening.

&&

More information, along with other weather, hydrological and climate
information can be found at http://weather.gov/ind

Special Weather Statement
National Weather Service Indianapolis IN
518 AM EDT Thu Jul 8 2021

INZ021-029-030-081000-
Clinton-Tippecanoe-Carroll-
518 AM EDT Thu Jul 8 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN CARROLL...TIPPECANOE
AND CLINTON COUNTIES...

At 517 AM EDT, a strong thunderstorm was located near Lafayette,
moving east at 30 mph.

Winds in excess of 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Lafayette, Frankfort, West Lafayette, Delphi, Flora, Rossville,
Shadeland, Dayton, Battle Ground, Mulberry, Colfax, Clarks Hill,
Burlington, Michigantown and Purdue University.

This includes Interstate 65 between mile markers 151 and 184.

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4018 8638 4019 8670 4021 8670 4021 8708
      4056 8706 4058 8637
TIME...MOT...LOC 0917Z 268DEG 28KT 4034 8685

NIELD