Severe Thunderstorm Warning 62, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
252 PM EDT SUN JUN 13 2010

.SYNOPSIS...
HOT AND HUMID CONDITIONS WILL CONTINUE INTO THE WORK WEEK. UPPER
LEVEL DISTURBANCES...IN THE NORTHWEST FLOW ALOFT...ALONG WITH A
SURFACE TROUGH OVER THE PIEDMONT AND WEAK LOW PRESSURE...KEEP
CHANCES OF THUNDERSTORMS IN THE FORECAST...ESPECIALLY DURING THE
AFTERNOON AND EVENING HOURS...AT LEAST THROUGH MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM...

SMALL BAND OF CONVECTION DROPPING INTO THE TRIAD AT THIS TIME WITH
ISOLATED SHOWERS FORECAST TO BECOME SLIGHTLY MORE NUMEROUS AND
DEVELOP THUNDER TOWARD LATE AFTERNOON. CONVECTIVE PARAMETERS
CONTINUE TO REMAIN HIGHEST EAST OF HIGHWAY ONE THIS AFTERNOON.
HIGH FREEZING LEVELS AND LACK OF MAJOR MID LEVEL DRYNESS SUGGEST
DAMAGING DOWNBURST WINDS ARE THE THREAT... BUT ONLY THE STRONGEST
STORM CORES MIGHT BE CAPABLE OF THIS. STILL EXPECT LOSS OF HEATING
TO DISSIPATE MOST IF NOT ALL CONVECTION BY 10 PM OR SO. HIGH
PRECIPITABLE WATERS OVERNIGHT WILL INHIBIT RADIATIONAL COOLING
TONIGHT FOR LOWS OF 70 TO 75 IN GENERAL.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 245 PM...

AIR MASS DRYS SLIGHTLY FOR MONDAY. LOW LEVEL THICKNESSES EXPECTED
TO EXCEED 1435 METERS MONDAY AFTERNOON. 850 MILLIBAR TEMPERATURES
AT LEAST 68 DEGREES OVER THE AREA... FOR MOSTLY MID 90 TEMPERATURES
AT THE SURFACE DURING THE AFTERNOON.

WEAK TROUGHING TO OUR EAST WILL LEAVE CENTRAL NORTH CAROLINA UNDER
A MID AND UPPER LEVEL RIDGE. AIR MASS CONTINUES QUITE UNSTABLE BUT
A SLIGHTLY DRIER AIR MASS AND POTENTIAL MID LEVEL CAPPING UNDER
THE RIDGE SUGGEST ONLY A SLIGHT RAIN CHANCE DURING THE MID TO LATE
AFTERNOON... BUT PERHAPS A SLIGHTLY HIGHER SEVERE THREAT THAN
TODAY. CONVECTION WILL AGAIN DISSIPATE IN THE MID TO LATE EVENING
MONDAY NIGHT. LOW LEVEL THICKNESSES ABOVE 1415 METERS AND
PRECIPITABLE WATERS WELL ABOVE 1.5 INCHES WILL RETURN LOW
TEMPERATURES TOT HE LOW TO MID 70S.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 245 PM SUNDAY...

STRONG MID AND UPPER LEVEL RIDGE OVER THE SOUTHEAST US WILL
DEAMPLIFY SLIGHTLY TUESDAY AND WEDNESDAY AS THE UPPER LOW CURRENTLY
OVER THE DESSERT SW EJECTS NE AND TRACKS TOWARDS THE UPPER GREAT
LAKES REGION.  MEANWHILE...MODELS INDICATE PROGRESSIVE SURFACE HIGH
PRESSURE BUILDING SE TO THE MID ATLANTIC COAST...PUSHING A BACKDOOR
BOUNDARY FROM NE TO SW INTO THE CWA LATE TUESDAY.  LATEST GUIDANCE
HAS BEEN IS MUCH SLOWER WITH THIS FEATURE AND THE RESULT IS LOW
LEVEL THICKNESSES UP NEAR 1440M ACROSS THE SOUTHERN CWA TUESDAY
AFTERNOON.  THIS WOULD RESULT IN HIGH IN THE MID TO UPPER 90S ACROSS
THE SOUTH WITH UPPER 80S TO LOWER 90S IN THE NE.  EXPECT DEWPOINTS
REMAIN HIGH IN THE UPPER 60S TO AROUND 70 TUESDAY...WITH PWS UP NEAR
2 INCHES.  THIS COMBINES WITH A SURFACE TROUGH FORECAST TO LIE
ACROSS THE SOUTHERN AND EASTERN CWA SHOULD CREATE A GOOD FOCUS FOR
SCATTERED SHOWERS AND STORMS TUESDAY AFTERNOON...LIKELY PRODUCING
LOCALLY HEAVY RAIN WITH SLOW MOVEMENT.

DEPENDING ON HOW FAR SOUTH THE AFOREMENTIONED BOUNDARY MAKES IT (AND
THIS REMAINS QUESTIONABLE GIVEN THE PROGRESSIVE NATURE OF THE HIGH
AND LACK OF MODEL CONSISTENCY)...SHOWERS MAY PERSIST WELL INTO THE
OVERNIGHT HOURS.  LOWS 66-72 NE TO SW.  THE SHALLOW NATURE OF THE
WEAK BACKDOOR COLD FRONT AND RAPIDLY DEVELOPING SW LOW LEVEL FLOW
SHOULD WASH OUT THE FRONT AND ALLOW HIGHS ON WEDNESDAY TO ONCE AGAIN
REACH THE UPPER 80S TO LOWER 90S.  CONVECTION SHOULD BE ISOLATED TO
THE ELEVATED TERRAIN AND THE SEA-BREEZE/PIEDMONT TROUGH.

THURSDAY ONWARD...ANOTHER SHORTWAVE EJECTING OUT OF THE FAIRLY
PERSISTENT WEST COAST TROUGH IS FORECAST TO LIFT NORTHEAST WELL INTO
CANADA...AS THE SOUTHERN US UPPER RIDGE HOLDS STRONG.  MODELS SHOW
THE POTENTIAL FOR ANOTHER WEAK BACKDOOR STYLE FRONT ON THE HEELS OF
LOW PRESSURE MOVING OFF INTO THE CANADIAN MARITIMES.  DURING THIS
TIME...THE UPPER RIDGE SHOWS SOME SIGNS OF RETROGRESSION TOWARDS THE
SOUTHERN PLAINS REGION...WHICH MAY ALLOW TEMPS TO RELAX
SLIGHTLY...THOUGH STILL JUST ABOVE NORMAL.  SHOULD SEE A RELATIVELY
WEST TO NORTHWEST FLOW DURING THE PERIOD...WITH LEE SIDE TROUGHING
AND DIURNALLY DRIVEN CONVECTION MOST DAYS.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 230 PM...

SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE TRIAD AREA AND
APPROACH THE TRIANGLE BEFORE DARK. ELSEWHERE SHOWERS AND A FEW
THUNDERSTORMS WILL DEVELOP WITH THE AFTERNOON HEATING. ALL
CONVECTION IS EXPECTED TO DISSIPATE OR EXIT TO THE EAST IN THE
LATE EVENING. ONCE CONVECTION ENDS VFR CEILINGS AND VISIBILITIES
WILL DOMINATE INTO LATE MORNING MONDAY WITH ONLY LOCALIZED MVFR
FOG TOWARD SUNRISE.

SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED TUESDAY INTO
FRIDAY...MAINLY AFTERNOON AND EVENING. THE GREATEST CHANCES FOR
AREAS OF IFR CONDITIONS OUTSIDE OF THUNDERSTORMS... ESPECIALLY
WITH REGARD TO LOW CLOUDS...WILL BE LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING.

&&

.CLIMATE...
RECORD HIGHS FOR JUNE 13/14 (SUNDAY/MONDAY):

SUNDAY JUNE 13:         MONDAY JUNE 14:
RDU: 100 IN 2002        RDU: 97 IN 1944
GSO: 96 IN 1945         GSO: 94 IN 1964

RECORD HIGH MINIMUM TEMPERATURES FOR THE MORNINGS OF JUNE 13/14/15:

SUNDAY JUNE 13:         MONDAY JUNE 14:         TUESDAY JUNE 15:
RDU: 74 IN 2005         RDU: 76 IN 2005         RDU: 73 IN 2004
GSO: 73 IN 2005         GSO: 71 IN 1945         GSO: 73 IN 1981

&&

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

&&

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...KRR
AVIATION...VINCENT
CLIMATE...

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
425 PM EDT SUN JUN 13 2010

NCZ007>011-021>028-038>043-073>078-083>086-088-089-142030-
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-
425 PM EDT SUN JUN 13 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THROUGH TONIGHT.

ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE SOUTH AND EAST OF THE
PIEDMONT TRIAD REGION AS A LINE OF SHOWERS AND THUNDERSTORMS MOVES
INTO A HOT UNSTABLE AIR MASS. THE PRIMARY THREAT WILL BE ISOLATED
DAMAGING WIND GUSTS WITH THE STRONGER STORMS ALONG THIS LINE. THE
LINE OF STORMS SHOULD BE MOVING INTO THE TRIANGLE REGION BETWEEN
430 PM AND 600 PM... AND FAYETTEVILLE AND GOLDSBORO BETWEEN 600
AND 700 PM. BRIEF HEAVY RAIN FOR 30 MINUTES ALONG WITH FREQUENT
LIGHTNING CAN BE EXPECTED.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE AGAIN DURING THE
AFTERNOON AND EVENING HOURS OF MONDAY AND TUESDAY.

VERY HOT AND HUMID CONDITIONS WILL CONTINUE MONDAY. HEAT INDICES
WILL LIKELY REACH 100 TO 105 FOR A FEW HOURS ESPECIALLY IN THE
COASTAL PLAIN REGION. BE SURE TO TAKE PRECAUTIONS FROM THE HEAT.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE ENCOURAGED TO REPORT ANY SEVERE OR
SIGNIFICANT WEATHER IMMEDIATELY TO THE NATIONAL
WEATHER SERVICE.

BADGETT

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
156 PM EDT SUN JUN 13 2010

NCZ021-022-131930-
FORSYTH-GUILFORD-
156 PM EDT SUN JUN 13 2010

...STRONG THUNDERSTORMS APPROACHING FORSYTH AND GUILFORD COUNTIES...

AT 153 PM EDT...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS 12 MILES
NORTH OF RURAL HALL...OR ABOUT 5 MILES WEST OF DANBURY...MOVING
SOUTHEAST AT 15 MPH.  THESE THUNDERSTORMS WILL MOVE INTO NORTHERN
FORSYTH AND GUILFORD COUNTIES BY 215 PM...AND WILL AFFECT THE CITIES
OF WINSTON-SALEM AND GREENSBORO THROUGH 300 PM.

LOCATIONS IN THE PATH OF THESE STORMS INCLUDE STOKESDALE...
KERNERSVILLE...COLFAX...SUMMERFIELD.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 40 TO 50 MPH.

SEEK SHELTER IN A NEARLY BUILDING OR VEHICLE. STRONG WINDS ARE
CAPABLE OF KNOCKING DOWN SMALL TREES AND BLOWING AROUND TRASH CANS...
POTTED PLANTS...LAWN FURNITURE AND OTHER LIGHT OUTDOOR OBJECTS.

&&

LAT...LON 3625 8046 3624 7959 3619 7953 3616 7953
      3602 7973 3598 8004 3601 8004 3602 8021
      3599 8021 3599 8033 3598 8035 3614 8045
TIME...MOT...LOC 1753Z 312DEG 15KT 3640 8030

22

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
329 PM EDT SUN JUN 13 2010

NCZ007-023-024-132030-
ALAMANCE-ORANGE-PERSON-
329 PM EDT SUN JUN 13 2010

...STRONG THUNDERSTORMS WILL MOVE ACROSS PERSON...NORTHERN ALAMANCE
AND NORTHERN ORANGE COUNTIES THROUGH 430 PM EDT...

AT 326 PM EDT...DOPPLER RADAR INDICATED A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM DANVILLE CITY TO 6 MILES
WEST OF CAMP SPRINGS...MOVING SOUTHEAST AT 25 MPH.

LOCATIONS IN THE PATH OF THESE STORMS INCLUDE...ELON COLLEGE...BUSHY
FORK...BURLINGTON...GRAHAM...MEBANE AND ROXBORO.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 30 TO 40 MPH.
DEADLY CLOUD TO GROUND LIGHTNING.

IF YOU SEE LIGHTNING OR HEAR THUNDER...YOU ARE AT RISK. TAKE SHELTER
INDOORS IMMEDIATELY. IF YOU CANNOT FIND SHELTER IN A BUILDING A
VEHICLE PROVIDES SAFETY FROM LIGHTNING.

&&

LAT...LON 3654 7884 3624 7894 3600 7915 3605 7954
      3625 7953 3624 7916 3655 7914
TIME...MOT...LOC 1926Z 278DEG 23KT 3658 7933 3627 7957

22

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