Alert archive / Tennessee / Special Weather Statements in 2018

Special Weather Statement, NWS Morristown, TN

August 30, 2018Greene County, Tennessee

NWS Morristown, TN issued this special weather statement at Aug 30, 2018, 4:02 PM EDT for Greene County, Tennessee. It was in force for 43 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
Aug 30, 2018, 4:02 PM EDT (20:02 UTC)
Expired
Aug 30, 2018, 4:45 PM EDT
In force
43 min
Issued by
NWS Morristown, TN

County Greene County, TN

The radar

The Knoxville radar (KMRX), 65 km from the middle of the area, began a volume at 20:05 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.0 hours before the alert went out and 249 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2018-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1345 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2018-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1345 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
1136 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
62 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 Morristown, TN wrote its last area forecast discussion before this special weather statement went out at Aug 30, 2:53 PM EDT, 1 hour 9 minutes earlier.

Area forecast discussion, Aug 30, 2:53 PM EDT, 1 hour 9 minutes before
Area Forecast Discussion
National Weather Service Morristown TN
253 PM EDT Thu Aug 30 2018

.SHORT TERM...(Tonight and Friday)...

Convection has largely been tied to the higher terrain of the
mountains and plateau regions so far today. Still expect it to
fill in somewhat over the valley so the 40-50% PoPs in the
forecast through this evening for those locations appear ok for
now. Time will tell if those are too high.

Otherwise, the region will remain beneath flat upper ridging over
roughly the southern half of the United States through the period.
More specifically, a weakness located beneath the subtropical high
located off the coast of the Carolinas and another over the New
Mexico and Texas border will be situated overhead. This weakness
will allow for another round of afternoon showers and
thunderstorms again tomorrow, mainly over the higher terrain. A
few isolated showers may also linger into, or form during, the
overnight hours tonight but typical diurnal trends should nix most
convection within a few hours of sunset this evening. Confidence
in how much skies clear out tonight is not high. Added in some
higher cloud cover over the major river valleys across the CWA to
hint at the possibility of some fog or low clouds tonight. But it
probably be hit and miss given possible cloud cover.

Temperatures tomorrow should be fairly similar to today, with mid
to upper 80s possible for lower elevations expected.

.LONG TERM...(Friday night through Thursday)...

Little change is needed to the previous forecast as a large ridge
over the western Atlantic continues to be the dominant feature
for the long term period. The ridge will gradually build westward
through the early part of the period, becoming positioned over the
central Appalachians by Wednesday/Thursday. Will see a trend
toward less convection, and temperatures will generally run
slightly above normal for the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             71  86  71  87 /  40  40  30  30
Knoxville McGhee Tyson Airport, TN  69  87  68  87 /  40  50  30  30
Oak Ridge, TN                       70  87  69  87 /  30  50  30  30
Tri Cities Airport, TN              66  86  65  87 /  40  50  50  30

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&

CD/LW
Hazardous weather outlook, Aug 30, 3:11 AM EDT, 12 hours 51 minutes before
Hazardous Weather Outlook
National Weather Service Morristown TN
311 AM EDT Thu Aug 30 2018

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-310715-
Cherokee-Clay-Scott TN-Campbell-Claiborne-Hancock-Hawkins-
Sullivan-Johnson-Morgan-Anderson-Union-Grainger-Hamblen-
Northwest Cocke-Cocke Smoky Mountains-Northwest Greene-
Southeast Greene-Washington TN-Unicoi-Northwest Carter-
Southeast Carter-Roane-Loudon-Knox-Jefferson-NW Blount-
Blount Smoky Mountains-North Sevier-Sevier Smoky Mountains-
Sequatchie-Bledsoe-Rhea-Meigs-McMinn-Northwest Monroe-
Southeast Monroe-Marion-Hamilton-Bradley-West Polk-East Polk-Lee-
Wise-Scott-Russell-Washington-
311 AM EDT Thu Aug 30 2018 /211 AM CDT Thu Aug 30 2018/

This Hazardous Weather Outlook is for portions of Southwest North
Carolina...East Tennessee and Southwest Virginia.

.DAY ONE...Today and Tonight

Slow-moving thunderstorms may be capable of producing localized
flooding and strong wind gusts.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

In the hours before

Special weather statement, Aug 30, 2:28 PM EDT, 1 hour 34 minutes before
Special Weather Statement
National Weather Service Morristown TN
228 PM EDT THU AUG 30 2018

TNZ071-072-301900-
Blount Smoky Mountains TN-NW Blount TN-
228 PM EDT THU AUG 30 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN BLOUNT COUNTY UNTIL 300
PM EDT...

At 227 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles north of Smoky Mountains-Twentymile Creek, or 12 miles
southeast of Maryville, moving southwest at 10 mph.

Dime size hail and winds in excess of 35 mph will be possible with
this storm.

Locations impacted include...
Cades Cove and Happy Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3547 8396 3549 8394 3550 8397 3549 8398
      3552 8400 3553 8399 3555 8400 3555 8402
      3562 8408 3571 8382 3557 8371 3556 8377
      3552 8383 3552 8388 3547 8392 3546 8395
TIME...MOT...LOC 1827Z 056DEG 7KT 3560 8384
Special weather statement, Aug 30, 2:35 PM EDT, 1 hour 27 minutes before
Special Weather Statement
National Weather Service Morristown TN
235 PM EDT THU AUG 30 2018

TNZ047-301900-
Southeast Carter TN-
235 PM EDT THU AUG 30 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN CARTER COUNTY UNTIL
300 PM EDT...

At 234 PM EDT, Doppler radar was tracking a strong thunderstorm near
Elk Park, or 7 miles west of Beech Mountain, moving west at 10 mph.

Dime size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Roane Mountain State Park, Elk Mills, Roan Mountain and Hampton Creek
Cove State Park.

LAT...LON 3615 8201 3616 8216 3632 8214 3629 8198
      3627 8196 3627 8195 3626 8195 3626 8193
TIME...MOT...LOC 1834Z 094DEG 10KT 3621 8202

CED
Special weather statement, Aug 30, 4:02 PM EDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 2:28 PM EDTSpecial Weather StatementMRXBlount32 min
Aug 30, 2:35 PM EDTSpecial Weather StatementMRXCarter25 min
Aug 30, 4:01 PM EDTSevere Thunderstorm WarningMRXScott44 min
Aug 30, 4:26 PM EDTSpecial Weather StatementMRXClaiborne49 min
Aug 30, 4:47 PM EDTSpecial Weather StatementMRXClaiborne28 min
Aug 30, 5:12 PM EDTSpecial Weather StatementMRXClaiborne33 min
Aug 30, 5:23 PM EDTSevere Thunderstorm WarningMRXHancock52 min
Aug 30, 5:33 PM EDTSpecial Weather StatementMRXUnion27 min
Aug 30, 5:58 PM EDTSpecial Weather StatementMRXKnox32 min
Aug 30, 6:43 PM EDTSpecial Weather StatementMRXMarion32 min
Aug 30, 6:49 PM EDTAreal Flood AdvisoryMRXMonroe116 min
Aug 30, 7:06 PM EDTSpecial Weather StatementMRXMonroe39 min
Aug 30, 7:27 PM EDTSpecial Weather StatementMRXMonroe33 min
Aug 30, 7:28 PM EDTSpecial Weather StatementMRXLoudon32 min
Aug 30, 1:33 PM EDTAreal Flood AdvisoryMRXWise, City of Norton3 hr
Aug 30, 5:06 PM EDTSpecial Weather StatementMRXRussell24 min
Aug 30, 6:39 PM EDTAreal Flood AdvisoryMRXWashington2 hr
Aug 30, 6:41 PM EDTSpecial Weather StatementMRXLee49 min
Aug 30, 7:36 PM EDTSpecial Weather StatementMRXScott39 min
Aug 30, 6:07 PM EDTSpecial Weather StatementMRXCherokee38 min
Aug 30, 7:04 PM EDTSpecial Weather StatementMRXCherokee26 min
Aug 30, 6:20 PM EDTSpecial Weather StatementMRXFannin25 min

Nearby

Special Weather Statements in Tennessee, 2018Every 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.