Severe Thunderstorm Warning 147, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
120 PM EDT SAT JUN 27 2009

.SYNOPSIS...
A WEAK FRONT WILL MOVE SOUTHEAST OF THE AREA THIS AFTERNOON.
ANOTHER WEAK FRONT MOVING INTO THE AREA LATE SUNDAY WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO CENTRAL NORTH
CAROLINA...PRIMARILY DURING THE LATE AFTERNOON AND EVENING HOURS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 120 PM SATURDAY...

A BROAD TROF OF LOW PRESSURE WAS LOCATED OVER EASTERN NC AND VA AT
MIDDAY. A WEAK COLD FRONT OVER SOUTHERN VA WILL MOVE SOUTH ACROSS
CENTRAL NC THIS AFTN AND EVE. DEWPOINTS CURRENTLY RANGE IN THE UPPER
60S ACROSS THE WESTERN PIEDMONT AND IN THE LOWER 70S FURTHER EAST IN
THE PIEDMONT AND COASTAL PLAIN. WATER VAPOR IMAGERY  SHOWS AN
ELONGATED AREA OF VORTICITY ASSOCIATED WITH MULTIPLE SHORT WAVES
OVER E PA AND THE NORTHEAST. AT JET LEVEL...A 115 KT JET WAS
ANALYZED NEAR KPIT THIS MORNING.

ENHANCED CLOUDINESS AND SCT CONVECTION ALREADY DEVELOPING IN THE NW
PIEDMONT EXPECTED TO DEVELOP THIS AFTERNOON AS THE UPPER LEVEL
DISTURBANCES ROTATE SOUTH AROUND THE DEEP LOW PRESSURE AREA OFF THE
NEW ENGLAND COAST. GREATEST CONVECTIVE COVERAGE SHOULD BE ACROSS THE
COASTAL PLAIN AND E SANDHILLS AHEAD OF THE SFC BOUNDARIES AND IN THE
LOCATION OF DEEPEST MOISTURE AND WILL INCLUDE GREATEST POPS THERE.
MLCAPE VALUES WILL CLIMB INTO THE 2000-2500 J/KG RANGE THIS AFTN IN
THE SE PARTS OF CWA NEAR KFAY AND KGSB. LATEST SPC MESOANALYSIS
ALREADY INDICATES OVER 1000 J/KG OF MLCAPE IN PARTS OF CENTRAL NC
WITH SOME CIN ASSOCIATED WITH A MID LEVEL CAP. LATEST AMDAR AIRCRAFT
SOUNDINGS INDICATE THE THE CAP IS STILL PRESENT AT KRDU AND KGSO AS
OF 13-15Z. AS TEMPS CLIMB FURTHER...INSTABILITY SHOULD INCREASE
SUFFICIENTLY FOR PARCELS TO BREAK THROUGH THE CAP LATER THIS AFTN
ALLOWING SCT DEEP CONVECTION TO COMMENCE. SPC HAS E NC AND E SC ARE
IN THE SPC SLIGHT RISK AREA THIS AFTERNOON. DEEP LAYER FLOW IS FROM
THE NW TO NE THIS AFTN/EVE WITH BULK SHEAR VALUES EXPECTED TO
INCREASE TO 25 TO 30 KTS WHICH WILL PROMOTE STORM ORGANIZATION INTO
BOWS AND MULTICELL CLUSTERS WITH A SUPERCELL OR TWO POSSIBLE. CELLS
THAT DEVELOP WILL BE VIGOROUS WITH A POTENTIAL FOR SIGNIFICANT
LIGHTNING.

WITH MAINLY CLEAR SKIES TEMPS HAVE WARMED QUICKLY INTO THE UPPER 80S
TO LOWER 90S AS OF 11 AM. LOW LEVEL THICKNESS VALUES FROM KGSO RAOB
SUPPORT TEMPS AT LEAST A COUPLE OF DEGREES HIGHER THEN YESTERDAY.
RAISED MAX TEMP FCST TODAY BY 2 OR 3 DEGREES IN MOST LOCATIONS WITH
THE AXIS OF HOTTEST TEMPS EXTENDING FROM THE RDU AIRPORT SOUTH AND
SOUTHWEST WHERE HIGHS WILL REACH THE UPPER 90S. DEWPOINTS IN THE
UPPER 60S WILL ALLOW HEAT INDEX VALUES TO EXCEED 100 DEGREES FOR
SEVERAL HOURS THIS AFTN.

AS THE SFC FRONT AND UPPER TROF SHIFT SE OF THE AREA THIS
EVENING...CONVECTION SHOULD DISSIPATE. EXPECT MAINLY CLEAR SKIES
OVERNIGHT. MINS WILL RANGE IN THE  66 TO 73 RANGE. -BLAES
&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 255 AM SATURDAY...

FOR SUNDAY/SUNDAY NIGHT: THE MID LEVEL LOW OVER NEW ENGLAND
CONTINUES TO WEAKEN AND EASE TO THE EAST AS A MID LEVEL WAVE NOW
PLOWING THROUGH WY/MT MERGES WITH ENERGY DROPPING SE FROM MANITOBA
TO DEEPEN A CLOSED LOW NEAR LAKE SUPERIOR. THE WEAK SURFACE FRONT
(NORTH OF WHICH THICKNESSES ARE JUST SLIGHTLY BELOW NORMAL) SHOULD
BE SETTLED ACROSS THE NC/SC BORDER WITH A LOW LIKELY OFF THE ILM
COAST EARLY SUNDAY. WITH DRY AIR MOVING INT... LIGHT / DIFFLUENT
MAINLY NORTHERLY SURFACE FLOW IN THE MORNING... AND THE BEST MID
LEVEL HEIGHT FALLS HAVING SHIFTED OFFSHORE... EXPECT NO PRECIP
THROUGH MIDDAY SUNDAY. AS THE MID LEVEL LOW DEEPENS OVER NRN MI
SUNDAY AFTERNOON AND THE SURFACE FRONT STARTS TO HEAD BACK NORTH AS
A WARM FRONT... A COLD FRONT WILL APPROACH FROM THE NW... PROPELLED
BY A 90+ KT UPPER JETLET. THE MODELS PLACE THE FRONT FROM THE OH/PA
BORDER SW THROUGH NRN KY AT 00Z MONDAY... WITH THE AIR MASS BECOMING
MODERATELY TO STRONGLY UNSTABLE JUST AHEAD OF THE FRONT... OVER AND
WEST OF THE MOUNTAINS. THE DRYING NWRLY BOUNDARY LAYER FLOW SHOULD
KEEP SURFACE DEWPOINTS LOW ENOUGH OVER THE NW CWA TO LIMIT
INSTABILITY. BUT THE GFS SHOWS 850-500 MB LAPSE RATES GETTING UP
NEAR 7.0 C/KM SUNDAY AFTERNOON WITH HUGE MUCAPES UP TO 4000-5000
J/KG... WHICH APPEARS EXCESSIVE. BASED ON THE INCOMING DYNAMIC
FORCING... PROXIMITY TO BETTER INSTABILITY... AND THE POTENTIAL FOR
STORMS TO FORM ON THE MOUNTAINS AND DROP INTO THE NW CWA AS 0-6 KM
SHEAR IMPROVES TO 35-40 KTS... WILL LEAVE IN AN ISOLATED CHANCE OF
THUNDER MID-LATE AFTERNOON. MODEL AVERAGE THICKNESSES SUPPORT HIGHS
OF 89-95. THEN SUNDAY NIGHT THE COLD FRONT HEADS SLOWLY EAST TRYING
TO EDGE INTO THE WRN PIEDMONT... WHILE THE WEAK SURFACE TROUGHING
PUSHES INTO THE COASTAL PLAIN. THE NAM/GFS DEPART WITH THEIR PRECIP
WITH THE GFS BLOWING UP NEARLY THREE-FOURTHS OF AN INCH SUNDAY
EVENING WHEREAS THE NAM IS LARGELY DRY. THE GFS IS MOST LIKELY
LATCHING ONTO THE EXTREME INSTABILITY AND GREATER LOW LEVEL MOISTURE
CONVERGENCE OVER ERN NC... BUT IT HAS BEEN SHOWING THIS TREND OF
LOCALLY HEAVY TOTALS IN CENTRAL/ERN NC FOR THE LAST FEW RUNS. IT MAY
BE ONTO SOMETHING AS PW VALUES TREND UP TOWARD 150% OF NORMAL ON
BOTH MODELS AND ITS FORECAST LCL-FREEZING LAYER HEADING OVER 3.5
KM... BUT WITH THE BULK OF THE JET FORCING APPEARING TO HEAD ACROSS
VA... ITS AMOUNTS ARE LIKELY TOO HIGH. THE CURRENT FORECAST HAD
CHANCE POPS FOR MUCH OF THE NIGHT AND HAVE OPTED TO MAKE FEW CHANGES
TO THIS... JUST REDUCING POPS A BIT OVER THE NRN AND WRN CWA BUT
KEEPING A 30-40% CHANCE EVERYWHERE THROUGH THE EARLY OVERNIGHT
HOURS. THICKNESSES ARE UNLIKELY TO DROP MUCH BEYOND SEASONAL
NORMALS... SO HAVE LOWS NEAR NORMAL... 65-71. -GIH

FOR MONDAY/MONDAY NIGHT: THE VORTEX WOBBLES ACROSS MI AND ENDS UP
OVER FAR SW ONTARIO BY DAYBREAK TUESDAY... WITH BROAD CYCLONIC FLOW
ALOFT OVER NC. WHILE THE SURFACE PATTERN BECOMES SOMEWHAT DIFFUSE...
THE NAM/GFS/CANADIAN/ECMWF SHOW THE FRONT PUSHING JUST TO OUR SE...
SITTING OVER THE EXTREME SERN CWA THROUGH MONDAY WITH MARGINAL TO
MODERATE DESTABILIZATION ALONG/EAST OF IT. BUT DRIER AIR CONTINUES
TO FILTER IN FROM THE WEST... WITH PW DROPPING BELOW NORMAL OVER ALL
BUT THE EXTREME SE CWA... AND WILL PUSH THE MENTION OF ISOLATED
THUNDER TO JUST THIS AREA FROM MID AFTERNOON TO MID EVENING. THE
MARKEDLY COOLER AIR GETS HELD UP WEST OF THE MOUNTAINS... AND
AVERAGING MODEL THICKNESSES POINTS TO HIGHS AROUND A CATEGORY ABOVE
NORMAL... 88-94. LOWS 65-71. -GIH

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...

DEEP TROUGHING OVER THE NORTHEAST QUARTER OF THE NATION KEEPS NC IN
A BRISK (THOUGH SLACKING OVER TIME) BROAD CYCLONIC BUT PRIMARILY
WESTERLY MID LEVEL FLOW. THE MID LEVEL VORTEX NEAR LAKE ERIE FILLS
SLOWLY AND WOBBLES NE ACROSS THE EASTERN GREAT LAKES THROUGH
WEDNESDAY... THEN THE GFS/ECMWF/CANADIAN SOLUTIONS DEPART
SIGNIFICANTLY WITH THEIR FALLING HEIGHTS OVER MANITOBA. YESTERDAY'S
12Z RUNS AGREED ON A DEEP VORTEX DEVELOPING OVER SCNTRL CANADA...
KICKING THE GREAT LAKES VORTEX TO THE NE AND LEADING TOWARD MORE
ZONAL FLOW INTO NC BY FRIDAY. BUT NOW THE 00Z GFS HAS MUCH HIGHER
HEIGHTS OVER SCNTRL CANADA AND MOVES THE GREAT LAKES LOW ONLY INTO
SRN QUEBEC. THE ECMWF... WHICH ALSO HAS TRENDED NOT AS DEEP OVER
CANADA... ACTUALLY TAKES SOME OF THIS ENERGY AND RE-DIGS THE GREAT
LAKES VORTEX BACK OVER NRN MI... ESSENTIALLY YIELDING VERY LITTLE
MOVEMENT OF THIS SYSTEM OVER 5 DAYS. THE CANADIAN IS IN BETWEEN BUT
CLOSER TO THE GFS. THE DETAILS ARE DIFFICULT TO DETERMINE THIS FAR
OUT... BUT EITHER WAY IT LOOKS A LARGELY DRY WESTERLY MID LEVEL FLOW
WITH SMALL TO NO LARGE SCALE FORCING MECHANISMS... NEAR NORMAL OR
LOWER PW... MILD AND STABLE MID LEVELS... AND WEAK PIEDMONT SURFACE
TROUGHING OVER NC. WILL CONTINUE WITH A DRY FORECAST FOR NOW...
ALTHOUGH LATER SHIFTS MAY NEED TO INCLUDE A SMALL CHANCE OF
AFTERNOON CONVECTION ALONG/EAST OF I-95 EACH AFTERNOON. WILL KEEP
TEMPS NEAR OR JUST ABOVE SEASONAL NORMALS... IN KEEPING WITH MEAN
MODEL-PROJECTED THICKNESSES. -GIH

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 120 PM SATURDAY...

A BROAD TROF OF LOW PRESSURE LINGERS ACROSS CENTRAL NC THIS
AFTERNOON. A COLD FRONT WILL DRIFT SOUTH ACROSS NC FROM VA AND MOVE
SOUTHEAST TOWARD THE COAST THIS AFTERNOON AND EVE. SFC FLOW IS
FAIRLY WEAK LESS THEN 10 KTS AND FROM THE NORTH AT MOST LOCATIONS.

A COUPLE OF DISTURBANCES IN THE MID LEVEL NORTHERLY FLOW WILL MOVE
ACROSS THE REGION THIS AFTN AND EVE. THESE FEATURES COMBINED WITH A
RELATIVELY MOIST AND UNSTABLE AIRMASS WILL RESULT IN SCT CONVECTION
THIS AFTERNOON AND EVE. LATEST SAT AND RADAR IMAGERY INDICATE
DEVELOPING SHOWERS/THUNDERSTORMS ACROSS THE NW PIEDMONT. WIDELY SCT
CONVECTION IS POSSIBLE ACROSS ALL TAF LOCATIONS THIS AFTN BUT BEST
COVERAGE OF CLOUDINESS AND CONVECTION WILL BE IN THE SOUTHERN AND
CENTRAL COASTAL PLAIN WHERE INSTABILITY IS GREATEST. UNSTBALE
AIRMASS WILL RESULT IN SCT TO BKN CU THIS AFTN WITH BASES AROUND 5-6
KFT. WILL INCLUDE MENTION OF CB TO HANDLE SHORT TERM CONVECTIVE
THREAT AND ADD TSRA WHEN CONVECTIONS THREATENS A PARTICULAR AIRPORT.

AS THE SFC FRONT AND UPPER TROF SHIFT SE OF THE AREA THIS
EVENING...CONVECTION SHOULD DISSIPATE. EXPECT MAINLY CLEAR SKIES
AFTER MIDNIGHT. INCREASING MID AND HIGH CLOUDINESS IS EXPECTED
DURING THE DAY SUNDAY WITH VFR CONDITIONS.

A WEAK FRONT WILL APPROACH THE AREA SUNDAY NIGHT WITH SCATTERED LATE
DAY CONVECTION ASSOCIATED WITH THE SYSTEM. THE SYSTEM EXITS TO THE
EAST EARLY MONDAY MORNING WITH VFR CONDITIONS PREVAILING INTO
THURSDAY. -BLAES

&&

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

&&

SYNOPSIS...MLM
NEAR TERM...BLAES
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...BLAES

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE RALEIGH NC
131 PM EDT SAT JUN 27 2009

NCZ007>010-021>024-038-039-281745-
PERSON-GRANVILLE-VANCE-WARREN-FORSYTH-GUILFORD-ALAMANCE-ORANGE-
DAVIDSON-RANDOLPH-
131 PM EDT SAT JUN 27 2009

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...SUNDAY THROUGH FRIDAY.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ011-025>028-040>043-073>078-083>086-088-089-281745-
HALIFAX-DURHAM-FRANKLIN-NASH-EDGECOMBE-CHATHAM-WAKE-JOHNSTON-WILSON-
STANLY-MONTGOMERY-MOORE-LEE-HARNETT-WAYNE-ANSON-RICHMOND-SCOTLAND-
HOKE-CUMBERLAND-SAMPSON-
131 PM EDT SAT JUN 27 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON
AHEAD OF A WEAK FRONT WHICH WILL BE MOVING ACROSS THE AREA.
A FEW STORMS COULD BECOME SEVERE...WITH A PRIMARY THREAT OF
DAMAGING WINDS AND SMALL HAIL. THE CHANCE FOR SEVERE WEATHER WILL
BE GREATEST BETWEEN 2 PM AND 8 PM EDT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE ENCOURAGED TO REPORT ANY SEVERE OR
SIGNIFICANT WEATHER ASSOCIATED WITH THESE STORMS.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
100 PM EDT SAT JUN 27 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0205 PM     TSTM WND DMG     SSW FAYETTEVILLE        35.07N 78.90W
06/26/2009                   CUMBERLAND         NC   FIRE DEPT/RESCUE

            ONE TREE DOWN ALONG ROADWAY IN DOWNTOWN FAYETTEVILLE.

&&

LEPAGANO