Alert archive / North Carolina / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 6, NWS Raleigh, NC

April 8, 2015Franklin County, Granville County, Vance County, North Carolina

NWS Raleigh, NC issued this severe thunderstorm warning at Apr 8, 2015, 7:45 PM EDT for Franklin County, Granville County, Vance County, North Carolina. It was in force for 45 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
Apr 8, 2015, 7:45 PM EDT (23:45 UTC)
Expired
Apr 8, 2015, 8:30 PM EDT
In force
45 min
Issued by
NWS Raleigh, NC
Area
Storm-based polygon

Counties Franklin County, NC, Granville County, NC, Vance County, NC

The radar

The Raleigh/Durham radar (KRAX), 65 km from the middle of the area, began a volume at 23:48 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

Roanoke, VA (KRNK), launched 12:00Z, 11.8 hours before the alert went out and 141 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, Roanoke, VA at 12:00Z on 2015-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 57 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, Roanoke, VA at 12:00Z on 2015-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 square meters per square second.193958Sfc1 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
57 J/kg
Mixed-layer CIN
-43 J/kg
Mixed-layer LCL
645 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
170 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 Apr 8, 3:20 PM EDT, 4 hours 25 minutes earlier.

Area forecast discussion, Apr 8, 3:20 PM EDT, 4 hours 25 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 PM EDT WED APR 8 2015

.SYNOPSIS...A BACKDOOR COLD FRONT WILL DROP INTO NORTHEAST NORTH
CAROLINA FROM THE NORTH LATE TONIGHT... THEN LIFT BACK NORTH LATE
THURSDAY. A COLD FRONT WILL APPROACH THE REGION LATE FRIDAY.

&&

.NEAR TERM /TONIGHT/...
AS OF 250 PM WEDNESDAY...

A PASSING MID-UPPER LEVEL IMPULSE OVER EAST-CENTRAL VA/NC HAS
RESULTED IN BRIEF SUBSIDENCE OVER CENTRAL NC IN THE WAKE OF THE
CONVECTION THAT AFFECTED OUR AREA EARLIER THIS MORNING. THE THREAT
OF SHOWERS AND STORMS WILL INCREASE ONCE AGAIN FOR THE EVENING AND
EARLY NIGHTTIME HOURS...AS A RESULT OF 1) THE ARRIVAL INTO THE NE
PIEDMONT AND NORTHERN-CENTRAL COASTAL PLAIN OF A BACKDOOR COLD FRONT
THAT WILL CONTINUE TO SETTLE SOUTHWESTWARD FROM NE NC THIS
AFTERNOON... 2) THE SHARPENING OF A LEE SFC TROUGH OVER THE NC NW
PIEDMONT AND FOOTHILLS...AND 3) THE APPROACH AND PROBABLE INFLUENCE
OF A COUPLE OF UPSTREAM MCS/S. WHILE THE FRONTAL ZONE MAY INITIATE
SCATTERED SHOWERS AND STORMS BY ITSELF...IT IS LIKELY THAT THE LEE
SFC TROUGH WILL REMAIN CONVECTIVELY INACTIVE UNTIL IT MERGERS WITH
ANOTHER BOUNDARY...EITHER IN THE FORM OF THE FRONTAL ZONE AS IT
SETTLES INTO SW VA...OR MORE LIKELY THE OUTFLOW FROM AN UPSTREAM MCS
- EITHER THE LEAD ONE OVER WESTERN WV OR A DEVELOPING MCS FARTHER
UPSTREAM OVER THE WESTERN TN VALLEY. ASSOCIATED SCATTERED TO
NUMEROUS SHOWERS AND STORMS ARE LIKELY TO DEVELOP SOUTHEASTWARD INTO
THE NW AND NORTHERN PIEDMONT THIS EVENING AND MERGE WITH ANY MORE
ISOLATED TO WIDELY SCATTERED ACTIVITY THAT DEVELOPS LATE THIS
AFTERNOON OR EVENING INVOF THE FRONT/TOWARD HNZ TO RWI.

PROVIDED STORMS DEVELOP...THERE WILL BE A CONDITIONAL THREAT OF
DAMAGING STRAIGHT LINE WINDS AND HAIL AS A RESULT OF STEEP TO MID
LEVEL LAPSE RATES CENTERED OVER WESTERN NC THIS AFTERNOON. SPC HAS
HIGHLIGHTED THE NW PIEDMONT IN A MARGINAL RISK TO ACCOUNT FOR THIS
POSSIBILITY...AND WE WILL ADD A BRIEF MENTION TO THE HWO. ONCE ANY
SHOWERS AND STORMS MOVE ESE AND/OR DISSIPATE OVERNIGHT...PARTIAL
CLEARING AND NE FLOW BEHIND THE AFOREMENTIONED BACKDOOR FRONT WILL
PROMOTE THE DEVELOPMENT OF LOW STRATUS AND FOG...WITH LOWS RANGING
FROM THE MIDDLE 50S NE TO LOWER 60S SW.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 300 PM WEDNESDAY...

THE FRONTAL ZONE...WHICH BY THAT TIME WILL LIKELY HAVE BEEN
MODULATED/PUSHED SOUTH BY OUTLFLOW...AND ASSOCIATED POST-FRONTAL LOW
CLOUDS...WILL RETREAT NORTH THU. ASSOCIATED CLEARING WILL BE SLOWEST
TO OCCUR NEAR THE VA BORDER...WHILE AREAS TO THE SOUTH RISE QUICKLY
INTO THE 80S. DEPENDING ON HOW SLOW THE STRATUS IS TO ERODE ACROSS
THE NORTH...TEMPERATURES COULD END UP SEVERAL DEGREES HIGHER THAN
CURRENT FORECASTS IN THE UPPER 70S TO NEAR 80 DEGREES. SCATTERED
AFTERNOON SHOWERS AND STORMS WILL BE POSSIBLE AREA-WIDE OWING TO THE
WARMTH AND HUMIDITY...THOUGH WITH THE RELATIVE BEST CHANCE INVOF THE
RETREATING FRONTAL ZONE OVER THE NORTHERN PIEDMONT. THERE SHOULD
THEN BE A LULL IN PRECIPITATION CHANCES DURING THE EARLY NIGHTTIME
HOURS AS THE BOUNDARY RETREATS INTO VA AND A BREEZY SSW FLOW
ENVELOPS CENTRAL NC. A CHANCE OF SHOWERS WILL RETURN TO THE WESTERN
PIEDMONT LATE...HOWEVER...IN RESPONSE TO HEIGHT FALLS ALOFT IN
ADVANCE OF THE PARENT UPPER TROUGH APPROACHING FROM THE MS VALLEY.
MILD AND MUGGY WITH LOWS IN THE LOWER TO MIDDLE 60S.

&&

LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 320 PM WEDNESDAY...

MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW
ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE
APPALACHAINS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS
SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH
GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S
NW TO MID 80S SE.  UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS
SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS
MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY
FLOW THERE'S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN
THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN
AHEAD OF THE FRONT.  SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING
BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN
THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY
BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT
AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY
NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE
MID 50S TO LOWER 60S.

TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS
ACROSS THE OH VALLEY AND MID-ATLANTIC STATES.  THE ECMWF SHOWS MORE
IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT
SKIES HERE SHOULD BE MOSTLY CLEAR.  THE GFS IS A TOUCH COOLER THAN
THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB
THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL
COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH.  WILL GO
WITH LOWS IN THE MID 40S.

THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS
SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER
THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US.  THE
MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL
INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE
THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER
AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A
LITTLE BETTER.  WILL ADJUST POPS  TO SHOW SLIGHTLY BETTER CHANCES IN
THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE
MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED
TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON
HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...

INITIALLY VFR CONDITIONS THIS AFTERNOON WILL YIELD TO SCATTERED TO
NUMEROUS SHOWERS AND STORMS WITH ASSOCIATED SUB-VFR CONDITIONS AND
GUSTY WINDS THIS EVENING AND EARLY TONIGHT...OWING TO BOTH THE
ARRIVAL OF A BACK DOOR FRONT FROM NE NC AND THE PROBABLE INFLUENCE
FROM A COUPLE OF UPSTREAM CONVECTIVE CLUSTERS STRETCHING THIS
AFTERNOON FROM THE CENTRAL APPALACHIANS TO THE WESTERN TN VALLEY.
FOG AND LOW STRATUS WILL BE PROBABLE LATE TONIGHT ONCE THE SHOWERS
AND STORMS DISSIPATE AND SKIES BRIEFLY PARTIALLY CLEAR. ASSOCIATED
LIFR-MVFR CONDITIONS WILL GRADUALLY TRANSITION THROUGH A PERIOD OF
MVFR CEILINGS THROUGH LATE MORNING TO MIDDAY THU...BEFORE LIFTING
AND SCATTERING TO VFR BETWEEN 14-18Z...SLOWEST AT NORTHERN TAF SITES.

OUTLOOK: ADDITIONAL SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE
AGAIN THU AFTERNOON...PARTICULARLY IN THE VICINITY OF THE RETREATING
FRONTAL ZONE...AT NORTHERN TAF SITES. A COLD FRONT WILL BRING A
BETTER CHANCE SHOWERS AND STORMS AND ASSOCIATED OF SUB-VFR
CONDITIONS FRI AFTERNOON AND EVENING.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...RAH
LONG TERM...22
AVIATION...RAH
Hazardous weather outlook, Apr 8, 3:10 PM EDT, 4 hours 35 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
310 PM EDT WED APR 8 2015

NCZ008>011-025>028-040>043-073>078-083>086-088-089-091915-
GRANVILLE-VANCE-WARREN-HALIFAX-DURHAM-FRANKLIN-NASH-EDGECOMBE-
CHATHAM-WAKE-JOHNSTON-WILSON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT-
WAYNE-ANSON-RICHMOND-SCOTLAND-HOKE-CUMBERLAND-SAMPSON-
310 PM EDT WED APR 8 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE ON FRIDAY
AFTERNOON...WITH THE MAIN THREAT FROM HAIL AND A SECONDARY THREAT
OF DAMAGING STRAIGHT LINE WINDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ007-021>024-038-039-091915-
PERSON-FORSYTH-GUILFORD-ALAMANCE-ORANGE-DAVIDSON-RANDOLPH-
310 PM EDT WED APR 8 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS MAY PRODUCE WIND GUSTS IN EXCESS OF 50 MPH AND
POSSIBLY LARGE HAIL THIS EVENING...MAINLY BETWEEN 8 PM AND
MIDNIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE ON FRIDAY
AFTERNOON...WITH THE MAIN THREAT FROM HAIL AND A SECONDARY THREAT
OF DAMAGING STRAIGHT LINE WINDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

In the hours before

Local storm report, Apr 8, 6:43 PM EDT, 1 hour 2 minutes before
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Local storm report, Apr 8, 6:57 PM EDT, 48 minutes before
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Special weather statement, Apr 8, 6:58 PM EDT, 47 minutes before
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Local storm report, Apr 8, 7:07 PM EDT, 38 minutes before
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Local storm report, Apr 8, 7:25 PM EDT, 20 minutes before
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Special weather statement, Apr 8, 7:27 PM EDT, 18 minutes before
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The office that day

Everything else NWS Raleigh, NC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 6:04 PM EDTSpecial Weather StatementRAHPerson56 min
Apr 8, 6:58 PM EDTSpecial Weather StatementRAHGranville, Vance62 min
Apr 8, 7:04 PM EDTSevere Thunderstorm WarningRAHGranville, Person41 min
Apr 8, 7:27 PM EDTSpecial Weather StatementRAHPerson33 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2015Every severe thunderstorm warning in 2015

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.