Alert archive / North Carolina / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 142, NWS Blacksburg, VA

September 29, 1999Surry County, North Carolina

NWS Blacksburg, VA issued this severe thunderstorm warning at Sep 29, 1999, 6:11 PM EDT for Surry County, North Carolina. It was in force for 49 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Sep 29, 1999, 6:11 PM EDT (22:11 UTC)
Expired: Sep 29, 1999, 7:00 PM EDT
In force: 49 min
Issued by: NWS Blacksburg, VA
Area: Whole counties

County Surry County, NC

The radar

The Roanoke radar (KFCX), 77 km from the middle of the area, began a volume at 22:10 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.

What was reported inside it

Time	Report	Where	Remark
Sep 29, 6:18 PM EDT	Thunderstorm Wind	Mt Airy, NC
Sep 29, 6:20 PM EDT	Tornado F1	Mt Airy, NC

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 10.2 hours before the alert went out and 80 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: 196 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 508 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 106 m²/s²
0-3 km storm-relative helicity: 94 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

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

NWS Blacksburg, VA wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 29, 2:10 PM EDT, 4 hours 1 minute earlier.

Area forecast discussion, Sep 29, 2:10 PM EDT, 4 hours 1 minute before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
210 PM EDT WED SEP 29 1999

17Z SFC ANALYSIS SHOWS CD FNT EXTENDING FROM LOW OVER LAKE ERIE
SOUTH THROUGH LEX TO CUMBERLAND PLATEAU IN TN. KRNK 88D SHOWS BATCH
OF RAIN GETTING READY TO EXIT ERN CWA WITH SCT TO BKN SHRA/TSRA
ELSEWHERE. RADAR COMPOSITE OF ERN U.S. SHOWS LINE OF TSRA ALG AND
AHEAD OF FNT IN CNTL AND ERN KY WITH LESS COVERAGE FURTHER SOUTH IN
TN. MAIN S/W ON WV CURRENTLY OVER WRN IL AND FURTHER NORTH THAN
MODELS DEPICTING. THIS WILL HAVE AN EFFECT ON PCPN COVERAGE THIS
EVENING AND EARLY TONIGHT. BELIEVE BST POOL OF MOISTURE CONVERGENCE
WILL BE IN NRN HALF OF CWA AND UPPER DIVERGENCE.

THIS DEFINES EVENING CONCERN FOR FFA...WHICH ATTM DOES NOT APPEAR TO
BE THE WAY TO GO. WILL LET SHORT TERM FORECASTS COVER POTENTIAL FOR
LOCALIZED SMALL STREAM FLOODING CONCERNS IF ANY. FNT SHOULD PICK UP
SPEED AS LOW SHOOTS OFF TO THE NORTHEAST INTO NY TONIGHT.

NEXT CONCERN IS HIGH WINDS FOR LATE TONIGHT AFTER FNT MOVES THROUGH.
LOW LEVEL FLOW TURNS NW ONCE FNT MOVES ACRS AND MODELS ARE PROGGING
30 TO 40 KNOT WINDS AT 850 FOR MUCH OF THE AREA WITH UP TO 30 KNOTS
DOWN AT 925 MB AND BL. FEEL THAT A HIGH WIND ADVISORY WOULD BE THE
WAY GO FOR AREAS ALONG AND WEST OF THE BLUE RIDGE MTNS INCLUDING THE
NEW RIVER VALLEY. THE HIGH WINDS WILL BE DURING A SMALL WINDOW OF
TIME FROM AFTER 06Z TO JUST B4 NOON THURSDAY.

PLAN ON GOING CATEGORICAL FOR ERN HALF OF CWA IN VA...AND ACRS SE WV
WITH LIKELY FURTHER SOUTH. WILL INVESTIGATE RADAR B4 ISSUING ZONES
AND MAY MAKE CHANGES AT LAST MINUTE DEPENDING ON COVERAGE.

BEST CAA IS LATE TONIGHT WITH NEUTRAL ADVECTION THU AFTN. THINK NGM
MOS MAY BE TOO HIGH ON TEMPS FOR THURSDAY AND AM LEANING TOWARD FAN
NUMBERS. HIGH PRESSURE TO KEEP US DRY THROUGH FRIDAY AND INTO THE
WEEKEND BEFORE TROPICAL MOISTURE WORKS NORTH AGAIN TOWARD SRN
APPLACHIANS LATE MONDAY GIVING US A CHANCE OF RAIN AS DEPICTED BY
MRF AND NOGAPS.

CALL WITH ANY COMMENTS/SUGGESTIONS. THANKS FOR THE
COORD...LWX...AKQ...RLX...GSP.

.RNK
VA...HIGH WIND ADVISORY FOR AREAS ALONG AND WEST OF BLUE RIDGE LATE
TONIGHT AND THURSDAY MORNING.
WV...HIGH WIND ADVISORY FOR SE WV LATE TONIGHT AND THURSDAY MORNING.
NC...HIGH WIND ADVISORY FOR NRN MTNS LATE TONIGHT AND THURSDAY
MORNING.

WHP

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 29, 4:05 PM EDT	Flash Flood Warning	RNK	Amherst	5 hr
Sep 29, 6:32 PM EDT	Severe Thunderstorm Warning	RNK	Patrick	63 min
Sep 29, 7:01 PM EDT	Tornado Warning	RNK	Patrick	59 min
Sep 29, 7:07 PM EDT	Severe Thunderstorm Warning	RNK	Carroll	48 min
Sep 29, 7:14 PM EDT	Flash Flood Warning	RNK	Campbell, City of Lynchburg	5 hr
Sep 29, 6:24 PM EDT	Tornado Warning	RNK	Surry	31 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 1999 Every severe thunderstorm warning in 1999

Sources

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