Heat Advisory 7, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
255 AM EDT MON JUL 9 2012

.SYNOPSIS...
A COLD FRONT STRETCHING EAST TO WEST ACROSS VIRGINIA WILL DRIFT
SLOWLY SOUTHWARD INTO NORTH CAROLINA BY LATE TODAY. THE FRONT WILL
THEN STALL AND LINGER OVER THE REGION THROUGH MUCH OF THE WORK
WEEK... BRINGING UNSETTLED WEATHER.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM MONDAY...

THIS MORNING: THE LATEST SURFACE ANALYSIS SHOWS THE SURFACE COLD
FRONT STRETCHING ACROSS MD AND SRN OH/IN/IL WITH A PRONOUNCED TROUGH
EXTENDING FROM NEAR RIC THROUGH CENTRAL NC. SCATTERED STORMS EARLY
THIS MORNING HAVE BEEN LARGELY CONFINED TO THE VA BORDER COUNTIES...
CLOSER TO THE BETTER UPPER DIVERGENCE AND THE MORE SUBSTANTIAL MID
LEVEL WESTERLY FLOW... ASSOCIATED WITH THE BROAD/FLAT MID LEVEL
TROUGH OVER NORTHEAST NOAM. MID LEVEL LAPSE RATES HAVE BEEN GREATER
THAN 6 C/KM OVER VA BUT REMAIN QUITE LOW OVER MUCH OF CENTRAL NC...
AND WITH VERY WEAK DEEP LAYER SHEAR AND ABUNDANT CONVECTIVE
INHIBITION... ISOLATED CONVECTION OUTSIDE OF THE VA BORDER REGION
HAS PULSED UP/DOWN QUICKLY (ESPECIALLY NEAR A SOUTHWARD-MOVING
OUTFLOW) WITH LITTLE OPPORTUNITY TO SURVIVE. BUT THE EFFECTIVE SHEAR
DOES APPROACH 20 KTS NEAR THE BORDER WHERE GRADIENTS IN BOTH MLCAPE
AND DOWNDRAFT CAPE ARE EVIDENT. WILL HOLD ONTO SCATTERED STORMS IN
THE FAR NORTHERN PORTION OF THE FORECAST AREA WITH LOW TO NO CHANCE
IN THE SOUTH... AWAY FROM ANY CONVECTIVE FOCI OR BOUNDARIES AND
WHERE MID LEVELS REMAIN COMPARATIVELY WARM/DRY. SKIES WILL BE PARTLY
TO MOSTLY CLOUDY IN THE FAR NORTH THIS MORNING BUT OTHERWISE MILKY
SUNSHINE WILL ALLOW FOR PLENTY OF HEATING... DRIVING TEMPS WELL UP
INTO THE UPPER 80S TO LOWER 90S BY NOON... AN EASY ACCOMPLISHMENT
GIVEN THE VERY WARM AND MUGGY DAYBREAK TEMPS IN THE MID 70S TO NEAR
80.

THIS AFTERNOON/TONIGHT: CONFIDENCE REMAINS HIGH IN THE DEVELOPMENT
OF NUMEROUS THUNDERSTORMS ACROSS THE FORECAST AREA THIS AFTERNOON.
AS THE MID LEVEL TROUGH DIGS ACROSS THE GREAT LAKES AND TO THE SSW
THROUGH THE MID SOUTH AND LOWER MISS VALLEY... THE EAST-WEST
ORIENTED COLD FRONT IS EXPECTED TO EASE SLOWLY SOUTHWARD THROUGH SRN
VA. MEANWHILE THE SURFACE TROUGH HOLDS THROUGH THE COASTAL PLAIN AND
SANDHILLS AS AN ASSOCIATED SURFACE LOW PROPAGATES TO THE SSW ALONG
THE TROUGH ACCORDING TO THE LATEST MODEL RUNS. THE EARLY-DAY
INSOLATION IS EXPECTED TO LEAD TO RAPIDLY GROWING INSTABILITY BY
AFTERNOON AS SURFACE DEW POINTS REMAIN NEAR 70 TO LOWER 70S.
LARGE-SCALE FORCING FOR ASCENT IS IMPROVING BUT STILL RATHER MODEST
WITH ONLY WEAK MID LEVEL DPVA AND MINIMAL HEIGHT FALLS ALOFT... BUT
STRENGTHENING UPPER DIVERGENCE OVER NRN NC IN THE RIGHT ENTRANCE
REGION OF THE 110+ KT JET OVER AND OFF THE NEW ENGLAND COAST IS
EXPECTED TO AUGMENT THE LIFT PRODUCED BY MODERATE TO STRONG
INSTABILITY (MLCAPE OF 2000-3000 J/KG) ALONG AND SOUTH OF THE
FRONT... LEADING TO EXPLOSIVE CONVECTION ACROSS CENTRAL NC BY EARLY
TO MID AFTERNOON AS INITIALLY NEAR-NORMAL PRECIP WATER VALUES RISE
TO NEAR 2.0 INCHES. WE SHOULD SEE NUMEROUS THUNDERSTORMS DEVELOP
OVER NORTHERN NC BY EARLY AFTERNOON... SPREADING SOUTHEAST THROUGH
THE AFTERNOON AND EARLY EVENING ALONG THE OUTFLOW-REINFORCED
EFFECTIVE FRONT AS IT DROPS THROUGH NC. DEEP LAYER SHEAR IS EXPECTED
TO IMPROVE TO 20-25 KT ALONG AND NORTH OF HIGHWAY 64 THIS
AFTERNOON... AND WITH CAPE IN THE MIXED-PHASE REGION (-10C TO -30C)
EXPECTED TO PEAK AT 900-1300 J/KG SUGGESTIVE OF VIGOROUS UPDRAFTS...
ANY STORMS COULD GENERATE STRONG TO DAMAGING WIND GUSTS AND HAIL
(ALTHOUGH THE HAIL RISK WILL BE TEMPERED SOMEWHAT BY WARM FREEZING
LEVELS). FREQUENT TO NEARLY CONTINUOUS LIGHTNING IS ALSO LIKELY WITH
SUCH A "FAT" CAPE PROFILE... HIGH K-INDEX VALUES OVER 36... AND HIGH
PRECIP WATER FLUX. AND THE OVERALL WEAK STEERING WILL RESULT IN
MEANDERING STORM CLUSTERS WITH SLOW MOVEMENT DICTATED BY OUTFLOWS...
PRESENTING A RISK OF URBAN FLOODING GIVEN THE HIGH ATMOSPHERIC WATER
CONTENT. WITH MORNING THICKNESSES PROJECTED TO BE AROUND 1430 METERS
AND PARTLY TO MOSTLY SUNNY SKIES IN THE MORNING...  EXPECT HIGHS OF
92-99... ALTHOUGH TEMPS WILL DROP INTO THE 80S WITH THE
APPROACH/ONSET OF CONVECTION. THESE WARM TEMPS AND DEW POINTS IN THE
LOWER 70S WILL NECESSITATE WHAT WE HOPE WILL BE THE LAST HEAT
ADVISORY OF THIS STRETCH... THIS TIME CONFINED TO THE SOUTHERN CWA.
EXPECT STORMS TO DECREASE IN INTENSITY AND COVERAGE GRADUALLY BY THE
OVERNIGHT HOURS AS THE BOUNDARY LAYER STARTS TO STABILIZE... BUT AT
LEAST SCATTERED SHOWERS AND A FEW STORMS SHOULD PERSIST THROUGH THE
NIGHT AS WEAK ELEVATED INSTABILITY PERSISTS. LOWS 70-75 UNDER MOSTLY
CLOUDY SKIES... WITH PATCHY FOG DEVELOPMENT ANTICIPATED. -GIH

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 235 AM MONDAY...

THIS PERIOD WILL BE DOMINATED BY A BROAD MID LEVEL TROUGH...WHILE AT
THE SURFACE...A TROUGH/WEAKENING FRONT WILL BISECT THE REGION FROM
NORTHEAST TO SOUTHWEST. LOW LEVEL FLOW WILL BRING IN MOISTURE FROM
THE GULF AND/OR ATLANTIC AND LEAD TO PWAT VALUES EXCEEDING 2 INCHES
THROUGHOUT THE PERIOD...ESPECIALLY ACROSS THE SOUTHEAST. THIS WILL
ALL RESULT IN SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EACH
DAY DURING THE SHORT TERM PERIOD. WILL HAVE THE HIGHEST POPS DURING
THE FAVORED DIURNAL HOURS...ALTHOUGH DO NOT EXPECT THE PRECIP TO
COMPLETELY COME TO AN END DURING THE OVERNIGHT HOURS. WITH REGARDS
TO ANY SEVERE THREAT...THE DEEP LAYER FLOW...SHEAR AND MID LEVEL
LAPSE RATES ARE ALL PROGGED TO BE RATHER WEAK...THEREFORE AM NOT
EXPECTING MUCH IN THE WAY ORGANIZATION. HOWEVER...CANNOT RULE OUT A
FEW ISOLATED STRONG TO SEVERE STORMS EACH AFTERNOON...WITH THE MAIN
THREAT BEING DAMAGING DOWNBURST WINDS...AS CAPE VALUES ARE PROGGED
TO BE ON THE ORDER OF 1500-2000 J/KG...HIGHEST ACROSS THE EAST. HIGH
TEMPS WILL BE BELOW NORMAL THROUGH THE PERIOD...GENERALLY MID TO
UPPER 80S DUE TO THE CONSIDERABLE CLOUD COVER AND ABOVE NORMAL
PRECIP CHANCES...WHILE THE OVERNIGHT LOWS WILL HOVER AROUND 70
DEGREES.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 AM MONDAY...

THE REMNANTS OF THE COLD FRONT WILL CONTINUE TO LINGER OVER THE AREA
THROUGH THE END OF THE WEEK. UPPER LEVEL FLOW WILL BE NEAR
NON-EXISTENT AND NO HELP IN MOVING THE FRONT ONE WAY OR ANOTHER.
THEREFORE...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PREVAIL EACH
DAY WITH THE MOST LIKELY TIMEFRAME COINCIDING WITH PEAK HEATING
DURING THE LATE AFTERNOON. AS THE WEEKEND APPROACHES...A HIGH
PRESSURE OFF OF THE SOUTHEAST COAST BEGINS TO TRY AND BUILD IN FROM
THE EAST. THIS COULD HELP EASTERN PORTIONS OF THE CWA BEGIN TO DRY
OUT LATE SATURDAY INTO SUNDAY. MAXIMUM TEMPERATURES DURING THIS
PERIOD WILL GRADUALLY INCREASE FROM THE MID 80S TO THE UPPER 80S BY
SUNDAY. LOW TEMPERATURES WILL REMAIN FAIRLY CONSISTENT...UPPER 60S
TO NEAR 70 DEGREES.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 145 AM MONDAY...

VFR CONDITIONS ARE NOTED AT ALL CENTRAL NC TERMINAL FORECAST SITES.
ISOLATED THUNDERSTORMS ARE POSSIBLE FOR THE REST OF THE NIGHT OVER
NORTHEAST PORTIONS OF CENTRAL NC BUT STORMS ARE LIKELY TO STAY
BEYOND 15 MI AWAY FROM RDU/RWI. OTHERWISE... CIGS WILL REMAIN ABOVE
6 THOUSAND FEET WITH VSBYS MOSTLY ABOVE 6 MILES THROUGH THE MORNING.
THE EXCEPTION WILL ARRIVE WITH AFTERNOON CONVECTION. NUMEROUS STORMS
WILL DEVELOP THIS AFTERNOON... FIRST NEAR INT/GSO/RDU/RWI AFTER
18Z... THEN SPREADING SOUTHWARD TO FAY AFTER 20Z. GUSTY WINDS AND
MVFR CIGS/VSBYS ARE POSSIBLE IN AND NEAR THESE STORMS FROM MID
AFTERNOON INTO EARLY EVENING. STORM COVERAGE WILL DECREASE AFTER 02Z
THIS EVENING... ALTHOUGH A FEW STORMS MAY OCCUR NEAR TAF SITES INTO
THE OVERNIGHT HOURS. OFFICIAL FORECAST KEEPS VFR CONDITIONS
PREVAILING TOWARD THE END OF THE TAF FORECAST PERIOD BUT POCKETS OF
MVFR FOG MAY BEGIN TO DEVELOP ESPECIALLY WHERE SURFACE WINDS GO
NEARLY CALM.

LOOKING BEYOND 06Z TONIGHT... AS NOTED ABOVE... MVFR VSBYS AND
PATCHY CLOUDS BASED BELOW 2 THOUSAND FEET WILL BE POSSIBLE AT ALL
SITES UNTIL DAYBREAK TUESDAY. THEN... THERE WILL BE A NEAR DAILY
CHANCE OF SCATTERED TO NUMEROUS SHOWERS AND STORMS... PRIMARILY IN
THE AFTERNOON THROUGH EARLY EVENING AT EACH TAF SITE THROUGH FRIDAY.
THERE IS A GOOD CHANCE FOR MVFR CIGS AND VSBYS EACH LATE-NIGHT AND
MORNING... AND IN/NEAR ANY STORMS... TUESDAY THROUGH FRIDAY. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR NCZ042-043-073>078-083>086-088-089.

&&

SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...KRR
LONG TERM...RTE
AVIATION...HARTFIELD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
912 PM EDT SUN JUL 8 2012

NCZ007>011-021>028-038>041-043-091000-
PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-FORSYTH-GUILFORD-ALAMANCE-
ORANGE-DURHAM-FRANKLIN-NASH-EDGECOMBE-DAVIDSON-RANDOLPH-CHATHAM-WAKE-
WILSON-
912 PM EDT SUN JUL 8 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THROUGH TONIGHT.

ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THROUGH 2 AM.
THE MAIN SEVERE WEATHER HAZARD SWILL BE LOCALLY DAMAGING
WINDS AND FREQUENT OR CONTINUOUS CLOUD TO GROUND LIGHTNING.

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

A COLD FRONT WILL SETTLE INTO THE AREA ON MONDAY... THEN PERSIST
OVER CENTRAL NC THROUGH MUCH OF THE WORK WEEK. STRONG TO SEVERE
THUNDERSTORMS ARE POSSIBLE ON MONDAY... WITH A PRIMARY THREAT OF
DAMAGING WIND GUSTS AS WELL AS LARGE HAIL. IN ADDITION... THE
FREQUENCY AND DURATION OF SHOWERS AND STORMS WILL RESULT IN A
THREAT OF HEAVY AND POTENTIALLY FLOODING RAINFALL THROUGHOUT THE
UPCOMING WEEK.

NCZ042-073>078-083>086-088-089-091000-
JOHNSTON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT-WAYNE-ANSON-RICHMOND-
SCOTLAND-HOKE-CUMBERLAND-SAMPSON-
912 PM EDT SUN JUL 8 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THROUGH TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

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

A COLD FRONT WILL SETTLE INTO THE AREA ON MONDAY... THEN PERSIST
OVER CENTRAL NC THROUGH MUCH OF THE WORK WEEK. STRONG TO SEVERE
THUNDERSTORMS ARE POSSIBLE ON MONDAY... WITH A PRIMARY THREAT OF
DAMAGING WIND GUSTS AS WELL AS LARGE HAIL. IN ADDITION... THE
FREQUENCY AND DURATION OF SHOWERS AND STORMS WILL RESULT IN A
THREAT OF HEAVY AND POTENTIALLY FLOODING RAINFALL THROUGHOUT THE
UPCOMING WEEK.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1145 PM EDT SUN JUL 8 2012

NCZ010-011-026-027-090445-
FRANKLIN-HALIFAX-NASH-WARREN-
1145 PM EDT SUN JUL 8 2012

...A STRONG THUNDERSTORM WILL MOVE ACROSS NASH...WARREN...HALIFAX AND
FRANKLIN COUNTIES THROUGH 1245 AM EDT...

AT 1144 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
WARRENTON...MOVING EAST AT 10 MPH.

SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...ARCOLA...LAKE
GASTON...LITTLETON...AND AIRLIE.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 30 TO 40 MPH.
DEADLY CLOUD TO GROUND LIGHTNING.
HEAVY RAINFALL AND MINOR FLOODING.

THIS INCLUDES INTERSTATE 85 BETWEEN EXITS 223 AND 233.

THIS INCLUDES INTERSTATE 95 BETWEEN EXITS 138 AND 173.

SEEK SHELTER IN A NEARBY BUILDING OR VEHICLE. STRONG WINDS ARE
CAPABLE OF BLOWING AROUND LIGHT OUTDOOR OBJECTS.

&&

LAT...LON 3651 7788 3648 7776 3649 7764 3645 7762
      3641 7754 3638 7754 3615 7770 3595 7780
      3613 7852 3618 7849 3616 7842 3623 7838
      3623 7834 3630 7828 3655 7832 3655 7790
TIME...MOT...LOC 0344Z 275DEG 8KT 3637 7808

10

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
118 AM EDT MON JUL 9 2012

NCZ040-076-090600-
CHATHAM-LEE-
118 AM EDT MON JUL 9 2012

...A STRONG THUNDERSTORM WILL MOVE ACROSS LEE AND CHATHAM COUNTIES
THROUGH 200 AM EDT...

AT 117 AM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
CUMNOCK...OR ABOUT 8 MILES SOUTH OF PITTSBORO...MOVING SOUTHEAST AT 5
MPH.

SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE... CUMNOCK...
MONCURE... AND SANFORD.

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

THESE STRONG WINDS ARE CAPABLE OF KNOCKING DOWN SMALL TREES AND
BRANCHES AND BLOWING AROUND TRASH CANS...POTTED PLANTS...LAWN
FURNITURE AND OTHER LIGHT OUTDOOR OBJECTS.

&&

LAT...LON 3580 7907 3562 7899 3561 7899 3561 7898
      3555 7895 3544 7905 3531 7919 3564 7942
TIME...MOT...LOC 0517Z 325DEG 6KT 3560 7919

GIH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
147 AM EDT MON JUL 9 2012

NCZ011-028-090645-
EDGECOMBE-HALIFAX-
147 AM EDT MON JUL 9 2012

...STRONG THUNDERSTORMS WILL MOVE ACROSS HALIFAX AND EDGECOMBE
COUNTIES THROUGH 245 AM EDT...

AT 146 AM EDT...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS 5 MILES
EAST OF ENFIELD...OR ABOUT 12 MILES SOUTH OF HALIFAX...MOVING EAST AT
15 MPH.

LOCATIONS IN THE PATH OF THESE STORMS INCLUDE TILLERY...ENFIELD...
HALIFAX...SCOTLAND NECK.

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

SEEK SHELTER IN A NEARBY 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 3608 7731 3600 7740 3594 7737 3594 7770
      3607 7774 3614 7770 3614 7772 3615 7776
      3640 7783 3645 7762 3641 7754 3637 7754
      3635 7758 3631 7756 3633 7744 3624 7737
      3622 7738 3616 7726 3610 7722
TIME...MOT...LOC 0546Z 261DEG 11KT 3616 7756

KRR