Alert archive / North Carolina / Severe Thunderstorm Warnings in 2013
Severe Thunderstorm Warning 117, NWS Raleigh, NC
NWS Raleigh, NC issued this severe thunderstorm warning at Aug 10, 2013, 2:32 PM EDT for Forsyth County, Guilford County, North Carolina. 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 counties it named.
The facts
- Issued
- Aug 10, 2013, 2:32 PM EDT (18:32 UTC)
- Expired
- Aug 10, 2013, 3:15 PM EDT
- In force
- 43 min
- Issued by
- NWS Raleigh, NC
- Area
- Storm-based polygon
Counties Forsyth County, NC, Guilford County, NC
The radar
The Roanoke radar (KFCX), 105 km from the middle of the area, began a volume at 18:35 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, 6.5 hours before the alert went out and 11 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.
- Mixed-layer CAPE
- 1595 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 669 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 28 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
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 Raleigh, NC wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 10, 1:30 PM EDT, 1 hour 2 minutes earlier.
Area forecast discussion, Aug 10, 1:30 PM EDT, 1 hour 2 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 130 PM EDT SAT AUG 10 2013 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL EXTEND ACROSS THE SOUTHEAST STATES THIS WEEKEND. MEANWHILE...A COLD FRONT WILL APPROACH SLOWLY FROM THE NORTHWEST...THEN STALL AND WEAKEN OVER OUR REGION ON MONDAY. A STRONGER COLD FRONT WILL ARRIVE DURING THE MIDDLE OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM SATURDAY... KEEPING A CLOSE EYE ON SHOWER/TSTM ACTIVITY TO OUR NORTH OVER CENTRAL VA AND WEST APPROACHING OUR TRIAD ZONES. ACTIVITY IS EXPECTED TO CONTINUE TO DEVELOP SOUTHWARD AND EASTWARD RESPECTIVELY ON OUTFLOWS AND PERHAPS EXPAND IN COVERAGE WITH NEW CELLS DEVELOPING INVOF THE PIEDMONT TROUGH. LATEST MESOANALYSIS SHOWS 3500+ J/KG SBCAPE ACROSS MOST OF OUR CWA...AND WHILE MID LEVEL LAPSE RATES ARE FAIRLY MODEST...A PWAT RIDGE OF 2+ INCHES LIES ACROSS AT LEAST THE NORTHERN HALF OF OUR CWA. BULK SHEAR LESS THAN 30 KTS SUGGESTS LIMITED ORGANIZATION...BUT GIVEN MOISTURE PROFILE AND CAPE...THE DEEPER CELLS SHOULD BE CAPABLE OF PRODUCING INTENSE DOWNPOURS... FREQUENT TO EXCESSIVE LIGHTNING...AND PERHAPS A FEW ISOLATED STRONG TO NEAR-SEVERE WIND GUSTS. GIVEN SW-NE ORIENTATION OF CURRENT ACTIVITY AND DEEP LAYER SW FLOW...WILL HAVE TO WATCH THE DIRECTION OF OUTFLOWS AND POTENTIAL FOR SOME CELL TRAINING...WHICH COULD LEAD TO POOR DRAINAGE AND URBAN FLOODING. IN TERMS OF COVERAGE...WITH MOISTURE DECREASING AND STABILITY INCREASING SOUTHWARD...THE BEST COVERAGE ACROSS CENTRAL NC THE REST OF THIS AFTERNOON AND EVENING SHOULD BE ACROSS THE NORTHERN HALF OF OUR CWA...WITH THE LEAST COVERAGE ACROSS OUR SE ZONES. WHILE MOST OF THIS ACTIVITY IS EXPECTED TO WIND DOWN BY MIDNIGHT... A FEW SHOWERS MAY PERSIST A LITTLE BEYOND MIDNIGHT...PARTICULARLY ACROSS OUR NE ZONES. OTHERWISE...PC SKIES THE REST OF THE NIGHT. SFC DWPTS ONCE AGAIN SUGGEST LOWS IN THE LOWER-MIDDLE 70S. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... AS OF 130 PM SATURDAY... SIMILAR PATTERN WILL BE IN PLACE ON SUNDAY WITH THE MID LEVEL RIDGE CENTERED JUST OFF THE SE COAST AND THE SFC FRONT REMAINING TO OUR NORTH. SCATTERED SHOWERS AND TSTMS ARE EXPECTED TO DEVELOP AFT 18Z ALONG THE PIEDMONT TROUGH AND ANY REMNANT/LINGERING OUTFLOW BOUNDARIES FROM TODAY'S ACTIVITY. CONVECTIVE PARAMETERS ON SUNDAY WILL BE VERY SIMILAR TO TODAY'S (SEE NEAR TERM DISC FOR DETAILS)...THUS THE MAIN CONCERNS WILL ONCE AGAIN BE LOCALIZED DOWNPOURS...FREQ-TO-EXCESS LIGHTNING...AND PERHAPS AN ISOLATED STRONG-TO-SEVERE WIND GUST. PERSISTENCE FOR HIGHS...89-92...WARMEST EAST. WILL CARRY CHANCE POPS INTO EARLY SUNDAY NIGHT FOR ANY LINGERING SHOWER/TSTM ACTIVITY...HOWEVER ACTIVITY SHOULD WIND DOWN AFT MIDNIGHT. LOWS SUNDAY NIGHT ONCE AGAIN IN THE LOWER 70S. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 130 PM SATURDAY... A VERY WET PERIOD SETTING UP FOR THE LONG TERM AS A FRONTAL ZONE DRAPES ACROSS THE CAROLINAS WITH PERSISTENT 2 TO 2.5 INCH PRECIPITABLE WATER VALUES BEING TRANSPORTED OUT OF THE EASTERN GULF OF MEXICO. THE MAIN SEVERE THREAT FOR THIS TIME PERIOD WILL BE FLASH FLOODING AS SEVERAL DAYS OF RAIN ARE EXPECTED WITH HIGHEST AMOUNTS LIKELY IN THE SOUTHEASTERN PORTIONS OF THE CWA. CURRENT 7 DAY PRECIPITATION FORECAST OUT OF THE WPC CALLS FOR AS MUCH AS 5 INCHES OF RAIN ALONG THE COAST WITH 3-4 INCHES LIKELY OVER SOUTHEASTERN PORTIONS OF THE CWA. BACK TO THE NORTHWEST...A LITTLE DRIER FORECAST IS EXPECTED BUT 2-3 INCHES OF RAIN DURING THIS PERIOD ARE STILL LIKELY. THE SURFACE FRONT IS PROGGED TO BE DRAPED ACROSS THE SOUTHERN PART OF THE CWA AS WELL AS SOUTH CAROLINA AND GEORGIA ON MONDAY. BY MONDAY EVENING THE FRONT WILL BEGIN TO SLOWLY CREEP BACK NORTHWARD AS A WARM FRONT...BUT MOVEMENT WILL BE SLOW DUE TO THE VERY ZONAL UPPER LEVEL PATTERN.BY TUESDAY THE UPPER LEVEL TROUGH WILL BEGIN TO DEEPEN INTO THE MISSISSIPPI VALLEY...HELPING THE FRONTAL ZONE ACROSS THE CAROLINAS TO MOVE NORTHWARD...ESPECIALLY IN THE EASTERN PART OF THE STATE. IN THE WEST...THE FRONT WILL REMAIN FURTHER SOUTH. A SURFACE HIGH OVER THE GREAT LAKES WILL STRENGTHEN ON WEDNESDAY WILL BEGIN TO CLEAR OUT THE NORTHWESTERN PART OF THE STATE AND KEEP THE FRONT CONFINED TO THE EASTERN HALF OF NORTH CAROLINA. IT IS DIFFICULT TO DETERMINE HOW BIG THE INFLUENCE OF THE HIGH WILL BE...IN PARTICULAR IF IT WILL KEEP THE NORTHWESTERN PIEDMONT DRY OR NOT. CHANCES FOR PRECIP WILL CERTAINLY INCREASE TO THE EAST. IN ADDITION...THE UPPER LEVEL JET STRUCTURE BECOMES MUCH MORE FAVORABLE FOR UPPER LEVEL DIVERGENCE BY WEDNESDAY AFTERNOON WITH A 50-75 KT 300MB JET SETTING UP OVER SOUTHERN VA. NOT MUCH TO CHANGE THE PATTERN ON THURSDAY AS THE SURFACE HIGH EXTENDS INTO THE NORTHEAST...WITH THE FRONT SANDWICHED BETWEEN IT AND THE BERMUDA HIGH...BISECTING THE CWA FROM SOUTHWEST TO NORTHEAST. AT THE UPPER LEVELS THE FRONT WILL REMAIN CAMPED ON THE FRONT SIDE OF THE TROUGH WITH AN UPPER LEVEL HIGH OFF THE FLORIDA COAST HELPING TO KEEP IT THERE. THIS PATTERN WILL KEEP THE GULF OF MEXICO OPEN FOR CONTINUED OPTIMAL MOISTURE TRANSPORT. FRIDAY THE HIGH WILL MIGRATE TO THE NORTHEASTERN CONUS AND BEGIN TO CREATE A WEDGE FRONT THAT WILL NOSE DOWN ALONG THE LEE OF THE APPALACHIANS...POSSIBLY SETTING UP AN OVERRUNNING PRECIP EVENT IF NOT BY FRIDAY THAN ON SATURDAY..AS A MESO LOW MOVES UP THE SOUTHEAST COAST...BRINGING ANOTHER SLOG OF MOISTURE WITH IT. NEAR AND SLIGHTLY BELOW NORMAL TEMPERATURES IN THE MID TO UPPER 80S MONDAY AND TUESDAY WILL QUICKLY DROP BACK TO THE LOWER 80S AND POSSIBLY EVEN UPPER 70S FOR HIGHS LATE IN THE FORECAST PERIOD. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 111 PM SATURDAY... VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE 24 HOUR TAF PERIOD...WITH THE EXCEPTION BEING DURING PERIODS OF SCATTERED SHOWER AND TSTM ACTIVITY THIS AFTERNOON AND EARLY EVENING...WHICH WILL LOCALLY REDUCE FLT CONDITIONS TO MVFR OR PERHAPS EVEN IFR IN THE HEAVIER DOWNPOURS. PRECIP EXPECTED TO END ACROSS CENTRAL NC BY 11/06Z WITH VFR CONDITIONS THE REST OF THE NIGHT. SIMILAR WEATHER PATTERN ON SUNDAY WILL MEAN VFR CONDITIONS THROUGH 11/16Z...THEN SCATTERED SHOWERS AND TSTMS DEVELOPING ONCE AGAIN DURING THE AFTERNOON. LOOKING AHEAD: PATCHY MORNING FOG AND/OR LOW STRATUS...AND SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND STORMS...WILL BE POSSIBLE THROUGHOUT THE PERIOD. THE RELATIVE BEST CHANCE OF SHOWERS AND STORMS WILL BE TUE AND TUE NIGHT...WHEN AN UPPER LEVEL TROUGH AND SURFACE COLD FRONT MOVE INTO OUR REGION. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...MWS NEAR TERM...NP SHORT TERM..NP LONG TERM...RTE AVIATION...NP/MWS
Hazardous weather outlook, Aug 10, 4:13 AM EDT, 10 hours 19 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RALEIGH NC 413 AM EDT SAT AUG 10 2013 NCZ007>011-021>028-038>043-073>077-110815- PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-FORSYTH-GUILFORD-ALAMANCE- ORANGE-DURHAM-FRANKLIN-NASH-EDGECOMBE-DAVIDSON-RANDOLPH-CHATHAM-WAKE- JOHNSTON-WILSON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT- 413 AM EDT SAT AUG 10 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. SCATTERED TO NUMEROUS THUNDERSTORMS...THE STRONGEST OF WHICH WILL BE CAPABLE OF PRODUCING STRONG TO MARGINALLY SEVERE WIND GUSTS AND LOCALIZED FLOODING...ARE EXPECTED THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. THE THREAT OF STRONG TO MARGINALLY SEVERE WIND GUSTS WILL AGAIN ACCOMPANY SCATTERED TO NUMEROUS THUNDERSTORMS ON SUNDAY. THUNDERSTORMS...WITH HEAVY RAIN AND LOCALIZED FLOODING...WILL BECOME MORE NUMEROUS TO WIDESPREAD ON TUESDAY. NCZ078-083>086-088-089-110815- WAYNE-ANSON-RICHMOND-SCOTLAND-HOKE-CUMBERLAND-SAMPSON- 413 AM EDT SAT AUG 10 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. SCATTERED TO NUMEROUS THUNDERSTORMS...THE STRONGEST OF WHICH WILL BE CAPABLE OF PRODUCING STRONG TO MARGINALLY SEVERE WIND GUSTS AND LOCALIZED FLOODING...ARE EXPECTED SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS...WITH HEAVY RAIN AND LOCALIZED FLOODING...WILL BECOME MORE NUMEROUS TO WIDESPREAD ON TUESDAY. MWS/CBL
In the hours before
Special weather statement, Aug 10, 1:44 PM EDT, 48 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
144 PM EDT SAT AUG 10 2013
NCZ021-101845-
FORSYTH-
144 PM EDT SAT AUG 10 2013
...STRONG THUNDERSTORMS APPROACHING FORSYTH COUNTY...
AT 142 PM EDT...DOPPLER RADAR INDICATED A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM RURAL HALL TO 6 MILES WEST
OF DONNAHA TO 21 MILES WEST OF HUNTSVILLE...OR ALONG A LINE EXTENDING
FROM KING TO EAST BEND TO 20 MILES NORTHWEST OF MOCKSVILLE...MOVING
EAST AT 20 MPH.
THROUGH 245 PM...THIS LINE OF STORMS WILL GRADUALLY MOVE EAST AND
AFFECT FORSYTH COUNTY. LOCATIONS THAT MAY BE AFFECTED INCLUDE...
DONNAHA...RURAL HALL...HUNTSVILLE...BELEWS CREEK...LEWISVILLE...AND
PFAFFTOWN.
HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS.
AN EXCESSIVE AMOUNT OF DEADLY CLOUD TO GROUND LIGHTNING.
HEAVY RAINFALL AND MINOR FLOODING.
DON'T WAIT UNTIL YOU SEE THE FIRST LIGHTNING FLASH BEFORE HEADING TO
SAFETY. MOVE INDOORS AT THE FIRST SIGN OF THREATENING SKIES OR THE
FIRST SOUND OF THUNDER. DEADLY LIGHTNING STRIKES CAN OCCUR WELL AHEAD
OF AN APPROACHING STORM...PRIOR TO THE ARRIVAL OF RAIN AND WIND. MAKE
SURE THAT LIGHTNING IS WELL AWAY FROM YOUR LOCATION BEFORE RESUMING
OUTDOOR ACTIVITY.
&&
LAT...LON 3611 8051 3614 8044 3622 8044 3626 8045
3626 8003 3601 8005 3603 8021 3600 8022
3600 8032 3597 8040 3599 8043 3601 8042
3606 8047 3604 8048 3605 8051 3609 8052
TIME...MOT...LOC 1742Z 288DEG 19KT 3628 8029 3624 8052
3602 8087Special weather statement, Aug 10, 2:29 PM EDT, 3 minutes before
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</html>The office that day
Everything else NWS Raleigh, NC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 8:00 PM EDT | Special Weather Statement | RAH | Stanly | 60 min |
| Aug 10, 1:44 PM EDT | Special Weather Statement | RAH | Forsyth | 61 min |
| Aug 10, 2:29 PM EDT | Special Weather Statement | RAH | Guilford | 61 min |
| Aug 10, 2:49 PM EDT | Special Weather Statement | RAH | Davidson | 56 min |
| Aug 10, 2:53 PM EDT | Areal Flood Advisory | RAH | Orange | 2 hr |
| Aug 10, 3:15 PM EDT | Special Weather Statement | RAH | Davidson | 60 min |
| Aug 10, 3:18 PM EDT | Special Weather Statement | RAH | Guilford | 57 min |
| Aug 10, 3:50 PM EDT | Special Weather Statement | RAH | Alamance, Chatham, Orange, Randolph | 55 min |
| Aug 10, 4:26 PM EDT | Special Weather Statement | RAH | Stanly | 64 min |
| Aug 10, 4:36 PM EDT | Special Weather Statement | RAH | Edgecombe | 39 min |
| Aug 10, 4:37 PM EDT | Special Weather Statement | RAH | Moore | 38 min |
| Aug 10, 4:45 PM EDT | Special Weather Statement | RAH | Chatham, Durham, Lee | 45 min |
| Aug 10, 4:54 PM EDT | Special Weather Statement | RAH | Wake | 51 min |
| Aug 10, 5:08 PM EDT | Severe Thunderstorm Warning | RAH | Durham, Franklin, Granville, Wake | 52 min |
| Aug 10, 5:11 PM EDT | Special Weather Statement | RAH | Davidson | 64 min |
| Aug 10, 5:15 PM EDT | Severe Thunderstorm Warning | RAH | Wake | 45 min |
| Aug 10, 5:32 PM EDT | Areal Flood Advisory | RAH | Wake | 88 min |
| Aug 10, 5:38 PM EDT | Special Weather Statement | RAH | Montgomery | 52 min |
| Aug 10, 5:41 PM EDT | Special Weather Statement | RAH | Johnston | 64 min |
| Aug 10, 5:46 PM EDT | Special Weather Statement | RAH | Nash | 59 min |
| Aug 10, 5:48 PM EDT | Special Weather Statement | RAH | Harnett | 57 min |
| Aug 10, 5:52 PM EDT | Severe Thunderstorm Warning | RAH | Johnston, Wayne, Wilson | 38 min |
| Aug 10, 5:55 PM EDT | Severe Thunderstorm Warning | RAH | Franklin, Nash, Wake | 50 min |
| Aug 10, 6:02 PM EDT | Special Weather Statement | RAH | Warren | 58 min |
| Aug 10, 6:10 PM EDT | Severe Thunderstorm Warning | RAH | Johnston, Nash, Wilson | 50 min |
| Aug 10, 6:26 PM EDT | Severe Thunderstorm Warning | RAH | Johnston, Wayne | 79 min |
| Aug 10, 6:30 PM EDT | Special Weather Statement | RAH | Edgecombe | 60 min |
| Aug 10, 6:40 PM EDT | Special Weather Statement | RAH | Cumberland | 65 min |
| Aug 10, 7:15 PM EDT | Special Weather Statement | RAH | Hoke | 60 min |
| Aug 10, 7:30 PM EDT | Special Weather Statement | RAH | Anson | 60 min |
Nearby
Severe Thunderstorm Warnings in North Carolina, 2013Every severe thunderstorm warning in 2013
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.