Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000
FXUS62 KRAH 030751
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
350 AM EDT FRI JUL 3 2015

.SYNOPSIS...
SURFACE LOW PRESSURE WILL TRACK EAST ACROSS NC AND VA LATER TODAY
AND TONIGHT...ALONG A FRONTAL ZONE THAT WILL LINGER OVER THE REGION
THROUGH THE HOLIDAY WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM THURSDAY...

ONLY A SMALL LINE OF SHOWERS/ISOLATED THUNDERSTORMS REMAINED FROM
NEAR TROY TO NEAR CLAYTON... MOVING SLOWLY E-NE AT 1000 PM. THIS
AREA STRETCHES ALONG THE OLD OUTFLOW BOUNDARY. A RECENT UPTICK IN
SHOWERS ALONG THIS BOUNDARY WAS OCCURRING WITH LOW TOPPED
CONVECTION... VERY LITTLE CG LIGHTNING. WE WILL FOLLOW THE MESO-
ANALYSIS AND RADAR TRENDS WHICH INDICATE AN AREA OF WEAK SURFACE
MOISTURE CONVERGENCE IN THIS REGION ALONG WITH SOME RESIDUAL MLCAPES
AROUND 500-1000 J/KG AND KEEP LIKELY POP GOING A BIT LONGER. TRENDS
DO SUGGEST LOCALLY 1 TO 2 INCHES OF ADDITIONAL RAINFALL FROM NEAR
CLAYTON TO WILSON AND SOUTH OF TARBORO IN A NARROW AXIS. SOME
TRAILING LOW TOPPED CONVECTION MAY GET GOING FOR A FEW HOURS ALONG
THE WEST EDGE OF THE OUTFLOWS AS WELL BACK OVER IN THE NW PIEDMONT.

OTHERWISE... THE ORGANIZED CONVECTION HAS ROUGHLY MOVED OFFSHORE AND
WAS APPROACHING THE WESTERN SLOPES OF THE APPALACHIANS FROM THE TN
VALLEY. THE ACTIVITY OVER THE TN VALLEY MAY HOLD TOGETHER INTO THE
MOUNTAINS. OTHERWISE... CONDITIONS ARE LESS FAVORABLE NOW EAST OF
THE MOUNTAINS. WE WILL CARRY A SLIGHT CHANCE OVERNIGHT. PARTLY
CLOUDY TO MOSTLY CLOUDY SKIES ARE EXPECTED WITH LOWS IN THE UPPER
60S TO LOWER 70S.

&&

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

FRIDAY...WATER VAPOR IMAGERY THIS AFTERNOON DEPICTS A WELL DEFINED
CONVECTIVELY INDUCE VORT MAX MOVING SEWD ON THE BACKSIDE OF THE
BAGGY UPPER LEVEL TROUGH. MODEL GUIDANCE HAS A FAIRLY GOOD HANDLE ON
THIS FEATURE. THIS SYSTEM PROJECTED TO ROUND THE BASE OF THE TROUGH
LATE TONIGHT/EARLY FRI THEN CROSS THE CAROLINAS LATER FRIDAY. BASED
ON CURRENT TIMING...SHOULD SEE SCATTERED CONVECTION DEVELOP A FEW
HOURS EARLIER THAN NORMAL...POSSIBLY AS EARLY AS 10-11 AM...WITH THE
MAJORITY OF THE CONVECTION OCCURRING BETWEEN NOON AND 8 PM.

THE LOW LEVEL ATMOSPHERE EXPECTED TO BE SLIGHT-MODERATELY UNSTABLE
ALONG WITH EFFECTIVE BULK SHEAR VALUES APPROACHING 30KTS...
SUPPORTIVE OF ORGANIZED CONVECTION. WIND PROFILE FAIRLY
UNIDIRECTIONAL (SW) SO EXPECT CONVECTION TO EVOLVE INTO BROKEN
BANDS...PRODUCING STRONG/LOCALLY DAMAGING WINDS.

MAX TEMPS FRIDAY DEPENDENT ON WHEN CONVECTION DEVELOPS AND EXTENT OF
CLOUD COVER OVERHEAD. EXPECT MORE CLOUDS THAN SUN NORTH AS WELL AS
MORE CONVECTION ACROSS THE NORTH SO SHOULD SEE A TEMP RANGE OF LOW-
MID 80S NORTH TO UPPER 80S/AROUND 90 SOUTH. EARLIER INITIATION OF
CONVECTION WILL LIKELY HAVE AN EFFECT ON MAX TEMPS (2-3 DEGREES
COOLER).

CURRENTLY APPEARS BULK OF ENERGY ASSOCIATED WITH THE VORT MAX EXITS
OUR REGION BY EARLY EVENING. THIS SUGGEST THAT CONVECTION SHOULD
SLOWLY WANE/DIMINISH BETWEEN 7-10 PM ACROSS THE REGION. SIMILAR TO
TONIGHT...PRESENCE OF OF A MOIST AIR MASS...A STALLED LOW LEVEL
TROUGH AND PERTURBATIONS ALOFT SUGGEST A FEW SHOWERS MAY LINGER INTO
THE OVERNIGHT HOURS. MIN TEMPS UPPER 60S-LOWER 70S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 345 PM FRIDAY...

A LOW AMPLITUDE SHORTWAVE CURRENTLY OVER THE US NORTHERN ROCKIES
WILL DIVE INTO THE BASE OF THE BROAD EASTERN US TROUGH ON SATURDAY
BEFORE ESSENTIALLY CUTTING OFF FROM THE FLOW AND DRIFTING UP THE
APPALACHIANS ON SUNDAY AND MONDAY...WHILE THE PERSISTENT SURFACE
FRONT/TROUGH FROM EARLIER IN THE WEEKEND REMAINS DRAPED ACROSS
CENTRAL NC.  THERE MAY BE SOME UNCERTAINTY IN INSTABILITY GIVEN
CONSIDERABLE CLOUDINESS EXPECTED EARLY SUNDAY...BUT THE COMBINATION
OF THE UPPER LOW...ALBEIT WEAK...AND SURFACE BOUNDARY AMIDST PW OVER
1.75" SHOULD LEAD TO NUMEROUS SHOWERS AND STORMS SUNDAY AND INTO
SUNDAY NIGHT.  BY THE MONDAY THE FRONT IS FORECAST SHIFT NORTH INTO
VA AND THE FOCUS OF SHOWERS/STORMS MAY SHIFT MORE TOWARD THE COASTAL
PLAIN.  THE LOW/MID LEVEL FLOW IS MUCH WEAKER SUNDAY/MONDAY AND
SEVERE STORMS MAY BE LESS OF A THREAT...BUT LOCALIZED FLOODING MAY
REAR ITS HEAD...PARTICULARLY IN THE VICINITY OF THE BOUNDARY.
CLOUDS AND PRECIP WILL LIKELY KEEP HIGHS LITTLE BELOW NORMAL IN THE
MID TO UPPER 80S...SLIGHTLY WARMER ON MONDAY.

BEYOND MONDAY... THERE ARE SOME SIGNS OF WARMING FOR THE MIDDLE OF
NEXT WEEK AND A LITTLE LESS PRECIP COVERAGE AS THE PROGRESSIVE
PATTERN EVENTUALLY YIELDS SOME REESTABLISHMENT OF THE SUB-TROPICAL
RIDGE OVER THE SOUTHEAST US WITH A COLD FRONT DYING JUST TO OUR
NORTH AROUND MIDWEEK.  HOWEVER...THE OVERALL PATTERN IS NOT VERY
AMPLIFIED AND TEMPS SHOULD REMAIN WITHIN A COUPLE DEGREES OF
NORMAL.


&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 230 AM FRIDAY...

THE PRESENCE OF A SURFACE FRONT DRAPED ACROSS THE NORTHERN NC
PIEDMONT --AND ASSOCIATED MOISTURE CONVERGENCE-- WILL LIKELY RESULT
IN THE CONTINUED DEVELOPMENT AND LOWERING OF IFR-MVFR STRATUS THIS
MORNING. THE STRATUS CLOUDS WILL GRADUALLY LIFT AND MORPH AFTER
DAYBREAK INTO A CUMULUS FIELD...WHOSE BASES ARE APT TO FLIRT WITH
THE 3000 FT/MVFR THRESHOLD THROUGH MIDDAY-EARLY AFTERNOON. PRIOR
CONVECTION AND ASSOCIATED AIR MASS STABILIZATION OVER CENTRAL NC
WILL CAUSE UPSTREAM CONVECTION CROSSING THE SOUTHERN APPALACHIANS TO
WEAKEN AS IT APPROACHES...THOUGH A FEW REMNANT SHOWERS CANNOT BE
RULED OUT IN THE 10-16Z TIME FRAME. HOWEVER...A BETTER CHANCE OF
SHOWERS AND STORMS WILL OCCUR WITH THE COMBINATION OF DIURNAL
HEATING AND THE APPROACH OF A DISTURBANCE ALOFT INITIALLY OVER THE
WESTERN TN VALLEY...AND AND INTERACTION WITH THE AFOREMENTIONED
FRONTAL ZONE...BETWEEN 16Z-00Z.

OUTLOOK: THE AFOREMENTIONED FRONT WILL STALL OVER VA/NC AND RESULT
IN ABOVE AVERAGE PROBABILITIES OF SHOWERS AND STORMS AND ASSOCIATED
SUB-VFR CONDITIONS THROUGH MON...WITH THE RELATIVE HIGHEST
PROBABILITY SUN-MON. PERIODS OF MVFR CEILINGS WILL BE POSSIBLE EVEN
OUTSIDE OF STORMS DURING THAT TIME...ESPECIALLY DURING THE MORNING
TO EARLY AFTERNOON HOURS.

&&

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

&&

$$

SYNOPSIS...26
NEAR TERM...PWB
SHORT TERM...WSS
LONG TERM...22
AVIATION...26



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