Alert archive / Tennessee / Special Weather Statements in 2018

Special Weather Statement, NWS Nashville, TN

June 11, 2018Cannon County, Tennessee

NWS Nashville, TN issued this special weather statement at Jun 11, 2018, 5:46 PM CDT for Cannon County, Tennessee. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jun 11, 2018, 5:46 PM CDT (22:46 UTC)
Expired: Jun 11, 2018, 6:30 PM CDT
In force: 44 min
Issued by: NWS Nashville, TN

County Cannon County, TN

The radar

The Nashville radar (KOHX), 63 km from the middle of the area, began a volume at 22:48 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 10.8 hours before the alert went out and 55 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 694 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 1001 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Nashville, TN wrote its last area forecast discussion before this special weather statement went out at Jun 11, 3:35 PM CDT, 2 hours 11 minutes earlier.

Area forecast discussion, Jun 11, 3:35 PM CDT, 2 hours 11 minutes before

Area Forecast Discussion
National Weather Service Nashville TN
335 PM CDT Mon Jun 11 2018

.DISCUSSION...

Latest radar imagery this afternoon shows scattered showers and
thunderstorms continue over the eastern half of the area,
although the bulk of the showers and storms are in the LMK, MRX,
HUN, and FFC forecast areas. This activity is expected to continue
mainly east of I-65 into early evening before diminishing with
loss of daytime heating. Over our western counties, water vapor
imagery shows considerable dry air and subsidence aloft, and this
has kept any showers and thunderstorms from popping up west of
I-65 despite temperatures near 90 and dewpoints in the upper 60s
to around 70. Overnight, models such as the HREF are indicating
some showers and storms may make a run at our northern zones from
Kentucky, but there's currently only a few storms up there so this
scenario is uncertain.

For tomorrow, majority of 12Z guidance indicates higher coverage
of showers and storms than today as a weak shortwave moves over
the region. Although some activity is possible in the morning
hours, most convection is expected in the afternoon to early
evening and should see decent coverage across the entire forecast
area. Forecast soundings are similar to today with MLCAPE around
1500 J/Kg, PWATs around 1.75 inches, lapse rates aloft in the 6-7
C/km range, and weak deep layer shear only around 10 knots. Thus
some strong to marginally severe thunderstorms will again be
possible, with the main threat being damaging winds from wet
microbursts. Wednesday looks fairly similar to Tuesday except for
a fast moving trough sweeping across the Great Lakes, which will
push a weak cold front towards Tennessee from the north. This
boundary may help increase coverage of convection Wednesday
afternoon and evening across our area, but will keep pops in the
chance category for now since front looks to remain north of us.
Forecast soundings for Wednesday are more unstable than Tuesday
with MLCAPE over 2000 J/Kg, steeper lapse rates and more dry air
aloft, and DCAPE over 1000 J/Kg. This along with the nearby front
suggests a higher potential for strong to borderline severe storms
on Wednesday, with again the main threat being damaging
microburst winds. SPC has parts of the area in a marginal risk for
severe weather on both days.

Later this week into the weekend, models continue to indicate
that the persistent upper ridge over the southern Plains will
shift eastward into the Mid-South and be centered just west of
Middle Tennessee, with 500mb heights rising to around 590-591dm.
This pattern will lower our rain chances to just isolated or low
chance each day from Thursday through Sunday, plus bump up our
heat even more with highs a few degrees warmer than what we are
having now. Although some mixing out of low level moisture will
occur each afternoon due to the upper ridge overhead, dewpoints
look to remain quite high in the mid 60s to lower 70s. This
combination of heat and humidity will start pushing our heat index
values up to near the uncomfortable 100 degree mark in some
locations. Both the 12Z GFS and ECMWF are suggesting the H5 ridge
will shift back to the west over the Southern Plains (where it
belongs) around a week from now, so cross your fingers that we
will see at least a slight decrease in the heat next week.

&&

.AVIATION...
18Z TAF DISCUSSION.

Scattered thunderstorms impacting the terminals will be the
greatest concern during this taf period. High resolution models
have been consistent showing CSV as having the best chance for
storms to impact at terminal with BNA and MQY having a lower
chance. Added a tempo -TSRA at CSV and left VCTS at BNA and MQY
due to the highly unstable airmass but removed the VCTS mention
from CKV due to models consistently showing storm coverage further
east. Fog will be possible tonight at CSV especially if the
terminal gets some rainfall. Winds will have a southerly/westerly
component through the taf period. 5-10 kt winds will relax this
evening and then pick back up around 15z on Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      70  90  71  91  70 /  20  50  40  50  20
Clarksville    70  89  70  89  68 /  20  50  40  40  20
Crossville     66  83  67  83  66 /  40  50  40  50  30
Columbia       68  89  70  89  69 /  20  50  40  50  30
Lawrenceburg   68  89  69  89  68 /  20  50  40  50  30
Waverly        70  89  70  89  69 /  20  50  40  40  20

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

DISCUSSION......Shamburger
AVIATION........Reagan

Hazardous weather outlook, Jun 11, 5:05 AM CDT, 12 hours 41 minutes before

Hazardous Weather Outlook
National Weather Service Nashville TN
505 AM CDT Mon Jun 11 2018

TNZ005>011-023>034-056>066-075-077>080-093>095-121015-
Stewart-Montgomery-Robertson-Sumner-Macon-Clay-Pickett-Houston-
Humphreys-Dickson-Cheatham-Davidson-Wilson-Trousdale-Smith-
Jackson-Putnam-Overton-Fentress-Perry-Hickman-Lewis-Williamson-
Maury-Marshall-Rutherford-Cannon-De Kalb-White-Cumberland-Bedford-
Coffee-Warren-Grundy-Van Buren-Wayne-Lawrence-Giles-
505 AM CDT Mon Jun 11 2018

This Hazardous Weather Outlook is for portions of Middle
Tennessee.

.DAY ONE...Today and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Scattered thunderstorms are expected Tuesday afternoon and
evening. Some of these storms may become strong to severe, with
damaging straight-line winds and large hail the primary threats.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed Tuesday afternoon and evening.

In the hours before

Special weather statement, Jun 11, 2:00 PM CDT, 3 hours 46 minutes before

Special Weather Statement
National Weather Service Nashville TN
200 PM CDT MON JUN 11 2018

TNZ065-066-080-111930-
Cumberland TN-Van Buren TN-White TN-
200 PM CDT MON JUN 11 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN CUMBERLAND...
NORTHEASTERN VAN BUREN AND SOUTHEASTERN WHITE COUNTIES UNTIL 230 PM
CDT...

At 200 PM CDT, Doppler radar was tracking a strong thunderstorm near
Spencer, moving east at 15 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Spencer, Indian Rock Lake and Fall Creek Falls State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3576 8508 3577 8510 3576 8526 3575 8526
      3573 8527 3572 8527 3566 8533 3570 8544
      3584 8543 3584 8506
TIME...MOT...LOC 1900Z 278DEG 15KT 3575 8535

10

Special weather statement, Jun 11, 4:22 PM CDT, 1 hour 24 minutes before

Special Weather Statement
National Weather Service Nashville TN
422 PM CDT MON JUN 11 2018

TNZ075-077-112200-
Coffee TN-Bedford TN-
422 PM CDT MON JUN 11 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN COFFEE AND
SOUTHEASTERN BEDFORD COUNTIES UNTIL 500 PM CDT...

At 422 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles northwest of Tullahoma, or 10 miles east of Shelbyville, moving
southeast at 5 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Shelbyville, Manchester, Tullahoma, Wartrace, Normandy, Raus,
Hillsboro, Arnold AFB and Woods Reservoir.

Bonnaroo will also be impacted.

LAT...LON 3532 8598 3531 8600 3534 8603 3536 8615
      3534 8620 3535 8623 3534 8626 3536 8625
      3537 8628 3538 8625 3539 8628 3540 8626
      3541 8625 3541 8629 3537 8634 3548 8641
      3563 8617 3533 8590 3529 8591
TIME...MOT...LOC 2122Z 322DEG 6KT 3547 8627

Whitehead

Special weather statement, Jun 11, 5:46 PM CDT, 0 minutes before

Special Weather Statement
National Weather Service Nashville TN
546 PM CDT MON JUN 11 2018

TNZ062-063-112330-
Cannon TN-Rutherford TN-
546 PM CDT MON JUN 11 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL RUTHERFORD AND
SOUTHWESTERN CANNON COUNTIES UNTIL 630 PM CDT...

At 546 PM CDT, Doppler radar was tracking a strong thunderstorm near
Murfreesboro, moving southeast at 20 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Murfreesboro, Woodbury, Bradyville, Lascassas and Readyville.

LAT...LON 3569 8619 3570 8620 3570 8622 3571 8622
      3570 8623 3587 8639 3594 8629 3587 8603
      3567 8615
TIME...MOT...LOC 2246Z 296DEG 19KT 3587 8631

21

The office that day

Everything else NWS Nashville, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 12:16 AM CDT	Special Weather Statement	OHX	Cannon, Warren	29 min
Jun 11, 12:27 AM CDT	Special Weather Statement	OHX	Wilson	33 min
Jun 11, 1:25 AM CDT	Areal Flood Advisory	OHX	Cannon	3 hr
Jun 11, 2:00 PM CDT	Special Weather Statement	OHX	Bledsoe	30 min
Jun 11, 4:22 PM CDT	Special Weather Statement	OHX	Coffee	38 min
Jun 11, 5:47 PM CDT	Special Weather Statement	OHX	Fentress, Pickett	58 min
Jun 11, 5:50 PM CDT	Severe Thunderstorm Warning	OHX	Cannon, Coffee, Rutherford, Warren	25 min
Jun 11, 6:15 PM CDT	Severe Thunderstorm Warning	OHX	Fentress, Pickett	34 min
Jun 11, 6:41 PM CDT	Special Weather Statement	OHX	Overton	49 min
Jun 11, 6:56 PM CDT	Special Weather Statement	OHX	Trousdale	49 min

Nearby

Special Weather Statements in Tennessee, 2018 Every special weather statement in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.