Severe Thunderstorm Warning 125, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
950 PM EDT MON AUG 12 2013

.SYNOPSIS...
A COLD FRONT WILL TRACK SOUTHEAST THROUGH CENTRAL NORTH CAROLINA
TUESDAY EVENING...THEN STALL OUT SOUTH OF THE REGION ON WEDNESDAY
AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM MONDAY

THE LOW LEVEL MOISTURE HAS RECOVERED NICELY ACROSS MUCH OF THE
REGION THAT MIXED OUT THIS AFTERNOON. DEW POINTS WERE GENERALLY IN
THE LOWER TO MID 70S THROUGHOUT THE REGION AT MID-EVENING. THE
ORGANIZED CONVECTION OVER THE NW PART OF THE STATE HAS PUSHED INTO
THE WINSTON-SALEM AREA... NOW PUSHING INTO THE REST OF THE PIEDMONT
TRIAD REGION. THE LATEST RAOB FROM GREENSBORO INDICATED SOME
DEVELOPING CINH... BUT MLCAPE OF 2000 J/KG AT RELEASE TIME. THE
ORGANIZED CONVECTION CONTINUED TO BE DRIVEN EASTWARD BY AN MCV
LOCATED JUST NORTHWEST OF DANVILLE VIRGINIA... WITH NEW CONVECTION
DEVELOPING ALONG TO THE SOUTHWEST OF THE MVC THROUGH THE PIEDMONT
TRIAD REGION. THE EARLIER PLACEMENT OF THE HIGHEST POP/QPF IN THE NW
WAS STILL IN LINE WITH THE CURRENT CONVECTION. HOWEVER... WE WILL
EXTEND THE INCREASED POP EASTWARD ALONG THE NC/VA BORDER THROUGH 200
AM TO ACCOUNT FOR THE MCV TRACKING EASTWARD NEAR THIS REGION. SINCE
THE AIR MASS IS STILL VERY UNSTABLE ACROSS THE REGION... WE WILL
MAINTAIN CHANCE POP IN ALL BUT THE FAR EAST-SOUTHEAST ZONES THROUGH
200 AM. AFTER THE MVC PASSES... CONVECTION SHOULD WANE RATHER
QUICKLY WITH INCREASING CINH AND SUPPORT. LOWS 70-75.

UPDATED GRIDS SENT. -BADGETT

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 PM MONDAY...

OVERVIEW:
SHORTWAVE ENERGY DIGGING SOUTH THROUGH MANITOBA/ONTARIO WILL TRACK
SOUTHEAST ACROSS THE GREAT LAKES ON TUE...AMPLIFYING CYCLONIC FLOW
ALOFT OVER THE MID-ATLANTIC/CAROLINAS. DPVA/HEIGHT FALLS WILL
AMPLIFY A LOW-LEVEL TROUGH AND SHARPEN A FRONTAL ZONE ACROSS THE
MID-ATLANTIC/CAROLINAS TONIGHT. THE LOW-LEVEL TROUGH AND SFC FRONT
WILL BECOME INCREASINGLY SW-NE ORIENTED AS THEY TRACK SOUTHEAST INTO
THE CAROLINAS TUE AFT/EVE...WITH THE FRONT PROGRESSING SOUTHEAST OF
CENTRAL NC AFTER MIDNIGHT AND APPROACHING THE NC/SC COAST BY 12Z WED.
SMALLER AMPLITUDE SHORTWAVE ENERGY APPROACHING THE CENTRAL MS RIVER
VALLEY THIS EVENING WILL TRACK EAST THROUGH THE TN VALLEY AND THE
VIRGINIAS TUE AFT/EVE.

PRECIPITATION CHANCES:
EXPECT DIURNAL DESTABILIZATION TO BE MOST PRONOUNCED ALONG/EAST OF
HWY 1 ON TUE...WHERE THE BEST LOW-LEVEL MOISTURE WILL BE PRESENT ON
THE EASTERN PERIPHERY OF THE TROUGH AND SFC FRONT PROGRESSING INTO
CENTRAL NC...WITH MLCAPE RANGING FROM ~2000 J/KG IN THE SE COASTAL
PLAIN TO ~1000 J/KG IN THE NW PIEDMONT. ASIDE FROM A LOW-LEVEL
MOISTURE GRADIENT...DESTABILIZATION WILL BE LIMITED BY WEAK
MID-LEVEL LAPSE RATES AND INCREASING CLOUD COVER ALONG/AHEAD OF THE
FRONT. GIVEN MODERATE INSTABILITY...A GOOD FOCUS IN THE FORM OF
SFC-H85 CONVERGENCE...AND A POTENTIAL FOR DPVA ASSOC/W SMALL
AMPLITUDE DISTURBANCES PROGRESSING EAST INTO THE VIRGINIAS IN
CYCLONIC FLOW ALOFT DURING THE AFT/EVE...ONE WOULD EXPECT SCATTERED
TO WIDESPREAD SHOWERS AND THUNDERSTORMS AT PEAK HEATING. THE LATEST
CONVECTION ALLOWING MODELS INDICATE A SW-NE ORIENTED LINE OF
CONVECTION DEVELOPING IN THE NW PIEDMONT BY MID/LATE AFTERNOON
(18-21Z)...PROGRESSING SOUTHEAST ACROSS CENTRAL NC AND EXITING THE
SE COASTAL PLAIN BY 03-06Z. THIS SCENARIO SEEMS VERY REASONABLE...
AND PRECIP CHANCES/TIMING WILL REFLECT AS MUCH.

TEMPERATURES:
EXPECT HIGHS SEVERAL DEGREES COOLER THAN PREVIOUS DAYS DUE TO
FALLING THICKNESSES AND INCREASING MID/UPPER LEVEL MOISTURE...
RANGING FROM THE UPPER 80S (NW) TO LOWER 90S (SE). LOWS TUE NIGHT
RANGING FROM THE MID/UPPER 60S (NW) TO LOWER 70S (SE).

SEVERE THREAT:
DEEP-LAYER SHEAR ON THE ORDER OF 30-40 KT IS EXPECTED TUE AFT/EVE...
SUPPORTIVE OF MULTICELL AND PERHAPS OCCASIONAL OR TRANSIENT
SUPERCELLULAR CHARACTERISTICS. GIVEN MOIST MID-LEVELS AND A
RELATIVELY MOIST BOUNDARY LAYER...DCAPE IS PROGGED TO BE ON THE WEAK
SIDE (500-750 J/KG)...REDUCING THE PROBABILITY OF STRONG/ORGANIZED
COLD POOLS AND LIKELY LIMITING THE SVR POTENTIAL TO ISOLD
DOWNBURSTS. DESPITE WEAK MID-LEVEL LAPSE RATES...MARGINALLY SVR HAIL
CANNOT BE RULED OUT GIVEN MODERATE INSTABILITY AND DEEP-LAYER SHEAR
SUPPORTIVE OF ROTATING UPDRAFTS. ANTICIPATE THE BEST SEVERE THREAT
ALONG/EAST OF HWY 1 BETWEEN 21Z TUE AFTERNOON AND 03Z TUE EVENING...
OR 5 PM THROUGH 11 PM. -VINCENT

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 200 PM MONDAY...

THE LONG TERM SETS UP TO BE AN EXTENDED PERIOD OF UNSETTLED WEATHER.
THAT BEING SAID...THE LATEST RUN OF THE GFS HAS COME IN A BIT
DRIER...ESPECIALLY FOR FOLKS IN THE TRIAD AS THE MAIN FRONTAL
BOUNDARY IS DEPICTED TO BE SOUTH OF MOST OF THE FORECAST AREA
THROUGH THE END OF THE WORK WEEK. BY THE WEEKEND...THE DEVELOPMENT
OF AN UPPER LEVEL LOW TO THE WEST AND A WAVE COMING OUT OF THE GULF
OF MEXICO HELP TO TRANSPORT COPIOUS AMOUNTS OF MOISTURE INTO THE
CAROLINAS FOR THE WEEKEND. GIVEN THAT CLIMATOLOGY AND THE ECMWF
SUGGEST THAT PERHAPS THE FRONT WILL NOT BE ABLE TO MAKE IT AS FAR
SOUTH AS SHOWN...THERE IS A GOOD CHANCE THE FRONT WILL SET UP
SOMEWHERE OVER OUR SOUTHERN TIER WITH HIGHEST QPF AMOUNTS SOUTH AND
EAST AND A LARGE GRADIENT WITH MUCH LESS TO THE NORTHWEST.

THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT WEDNESDAY WILL BEGIN
WITH THE FRONT SOMEWHERE IN THE VICINITY OF US HIGHWAY 64 OR
SLIGHTLY SOUTH. FROM HERE THE GFS IS VERY PROGRESSIVE BRINGING THE
FRONT THROUGH THE CWA BY WEDNESDAY AFTERNOON WHEREAS THE ECMWF IS
ALMOST STATIONARY WITH IT. BY EVENING...PRECIPITATION SHOULD BE
LIMITED TO EAST OF I-95. THIS SOLUTION HOLDS THROUGH THURSDAY
KEEPING MOST PRECIP CONFINED TO THE SANDHILLS AND COASTAL PLAIN.

ON FRIDAY SOLUTIONS START TO DIFFER WITH THE GFS PRODUCING A VERY
WIDE WEDGE WHICH PUSHES PRECIP BACK OUT OF THE STATE TO THE SOUTH.
THE ECMWF SEEMS MORE REALISTIC WITH SOME OVERRUNNING PRECIP COVERING
AT LEAST SOME OF THE FORECAST AREA FOR MOST OF THE DAY ON FRIDAY.

SATURDAY IS WHEN A REINFORCEMENT OF MOISTURE OCCURS WITH A
SHORTWAVE MOVING UP FROM THE GULF OF MEXICO. WHILE THE GFS IS
FORMING THIS INTO AN ORGANIZED TROPICAL SYSTEM AS IT APPROACHES THE
FLORIDA PANHANDLE...THIS APPEARS UNLIKELY DUE TO UNFAVORABLE UPPER
LEVEL CONDITIONS FOR TROPICAL DEVELOPMENT. A MORE REALISTIC SOLUTION
IS THAT OF THE ECMWF WHICH HAS A MORE UNORGANIZED WAVE MOVING UP
THROUGH GA AND SC. EITHER WAY THE OUTCOME IS THE SAME...A VERY WET
WEEKEND FOR CENTRAL NC. THE 7 DAY QPF FORECAST FROM WPC REMAINS
LARGELY UNCHANGED WITH 5-6 INCHES EXPECTED ON THE COAST WITH 3-4
BACK OVER CENTRAL NC. GFS FORECAST SOUNDINGS SHOW VERY WET TROPICAL
SOUNDINGS FOR SATURDAY WITH HIGH SHEAR BUT NO INSTABILITY. IT WOULD
NOT TAKE MUCH INSOLATION THOUGH TO BREAK OUT AND CAUSE SOME TALL
SKINNY CAPE PROFILES. THIS WOULD SET UP A POTENTIAL HIGH SHEAR
LOW CAPE SEVERE WX SCENARIO. THIS THREAT IS EVEN MORE PRONOUNCED ON
SUNDAY WHEN AT LEAST 500 J/KG OF INSTABILITY IS FORECASTED WITH
30-50 KNOTS OF SHEAR AVAILABLE. IN ADDITION...THE STRONGEST SHEAR ON
SUNDAY IS IN THE LOWEST FEW KM OF THE ATMOSPHERE...INDICATING THAT
THE POTENTIAL FOR ROTATING STORMS AND AN ISOLATED TORNADO COULD BE
THERE.

FORECASTS FOR MONDAY OF NEXT WEEK ARE LOW CONFIDENCE AT THIS POINT
BUT MODELS STILL SHOW PLENTY OF MOISTURE IN THE AREA...ESPECIALLY
FROM HIGHWAY 1 EASTWARD. EXPECT YET ANOTHER DAY OF UNSETTLED WEATHER.

TEMPERATURES WILL START OUT IN THE LOW TO MID 80S ON WEDNESDAY
BEFORE GENERALLY FALLING INTO THE UPPER 70S IN THE NW TO LOW 80S SE
FOR MUCH OF THE PERIOD. A WARMING TREND IN THE EAST AT THE END OF
THE PERIOD WILL BRING HIGHS BACK INTO THE MIDDLE 80S. LOWS WILL
GENERALLY BE LOW TO MID 60S EARLY IN THE PERIOD WITH MID TO UPPER
60S FORECAST BY EARLY NEXT WEEK. -ELLIS

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 820 PM MONDAY...

24-HR TAF PERIOD:
VFR CONDITIONS ARE GENERALLY EXPECTED THIS EVENING AND OVERNIGHT.
HOWEVER... WE MAY SEE SOME OF THE ACTIVITY ACROSS
SOUTHERN/SOUTHWESTERN VA WORK INTO NORTHERN PORTIONS OF CENTRAL NC
THIS EVENING... WHILE CONVECTION ACROSS THE SOUTHERN COASTAL PLAIN
OF NC MAY ALLOW FOR SHOWER AND STORM DEVELOPMENT INVOF KFAY AND
PERHAPS KRWI ALONG OUTFLOW BOUNDARIES RACING NORTH AND EASTWARD
(FROM THE CURRENT ACTIVITY JUST TO THE SOUTH AND EAST OF SAMPSON
COUNTY). KFAY STANDS THE BEST CHANCE TO SEE ANY ACTIVITY. THUS...
HAVE ADDED A TEMPO GROUP FROM 01Z TO 05Z FOR MVFR CONDITIONS THERE.
ELSEWHERE WILL HANDEL ANY CONVECTION WITH AMENDMENTS... AS
CONFIDENCES IS TOO LOW AT THIS TIME TO INCLUDED ANY MENTION OF
CONVECTION AT THE REST OF THE CENTRAL NC TAFS. ANY CONVECTION THAT
MAKES IT INTO CENTRAL NC COULD LINGER INTO THE EARLY MORNING HOURS
OF TUESDAY. GIVEN NO TAF SITES HAVE BEEN AFFECTED BY ANY CONVECTION
TODAY... EXPECT WE SHOULD SEE GENERALLY VFR CONDITIONS AFTER ANY
LINGERING CONVECTION DIES OFF. IF A TAF SITES DOES INDEED PICK A
SIGNIFICANT SHOWER/STORM THIS EVENING THEN IFR/LIFR CONDITIONS WILL
BE POSSIBLE. HOWEVER... EITHER WAY HAVE ELECTED TO KEEP A TEMPO FOR
IFR VISBYS AT KRWI... GIVEN THE MOIST LOW LEVEL AIR MASS AN THE
POTENTIAL FOR AT LEAST SOME BREAKS IN THE MID/HIGH LEVEL CLOUD COVER
IN THE EARLY MORNING HOURS AFTER THE MAIN AREA OF CONVECTION DIES
OFF... ALONG WITH THE FOG PRONE HISTORY OF KRWI.

A COLD FRONT WILL APPROACH AND MOVE INTO CENTRAL NC ON
TUESDAY/TUESDAY AFTERNOON. THIS SHOULD ALLOW FOR WIDESPREAD SHOWERS
AND STORMS ACROSS THE AREA TUESDAY AFTERNOON INTO TUESDAY EVENING.
THUS... HAVE ADDED VCTS AND CB TO ALL TAF SITES STARTING AT 18Z. ANY
STORMS THAT AFFECT A GIVEN SITES WILL HAVE THE POTENTIAL TO PRODUCED
GUSTY WINDS AND SUB-VFR CONDITIONS.

LOOKING AHEAD:
VFR CONDITIONS ARE EXPECTED BY MID/LATE WEDNESDAY MORNING AS THE
FRONT PUSHES TO THE SOUTH OF THE AREA. THE FRONT WILL STALL OUT JUST
SOUTH OF CENTRAL NC AND IT IS POSSIBLE THAT THE KFAY COULD SEE A
CONTINUED CHANCE OF SHOWERS/STORMS DURING THE AFTERNOON AND EVENING
HOURS WED/THUR.

&&

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

&&

SYNOPSIS...BADGETT
NEAR TERM...BADGETT
SHORT TERM..VINCENT
LONG TERM...ELLIS
AVIATION...BSD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
737 PM EDT MON AUG 12 2013

NCZ007>011-021>028-038>043-073>078-083>086-088-089-132345-
PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-FORSYTH-GUILFORD-ALAMANCE-
ORANGE-DURHAM-FRANKLIN-NASH-EDGECOMBE-DAVIDSON-RANDOLPH-CHATHAM-WAKE-
JOHNSTON-WILSON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT-WAYNE-ANSON-
RICHMOND-SCOTLAND-HOKE-CUMBERLAND-SAMPSON-
737 PM EDT MON AUG 12 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THROUGH TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY AFTERNOON
AND EVENING. AN APPROACHING COLD FRONT WILL PUSH SOUTHEAST
THROUGH CENTRAL NORTH CAROLINA TUESDAY EVENING. SCATTERED
THUNDERSTORMS ARE EXPECTED TUESDAY AFTERNOON AND EVENING. A FEW OF
THESE STORMS MAY BECOME SEVERE WITH A A PRIMARY THREAT OF DAMAGING
WIND GUSTS TO 60 MPH.

A WET PERIOD IS POSSIBLE OVER THE WEEKEND. HOWEVER... MODEL
CONFIDENCE HAS DECREASED. THEREFORE THE CONFIDENCE OF THE
FORECAST TIMING AND PLACEMENT OF WIDESPREAD HEAVY RAIN HAS ALSO
DECREASED.

BADGETT

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>