Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 271934
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
335 PM EDT WED APR 27 2016

.SYNOPSIS...
A WEAKENING FRONTAL ZONE WILL APPROACH THE AREA FROM THE NORTHEAST
TODAY...THEN STALL OVER OR NEAR THE AREA THROUGH LATE WEEK.
A COLD FRONT WILL PUSH SOUTH OF THE REGION FRIDAY NIGHT... THEN LIFT
BACK NORTHWARD AS A WARM FRONT SUNDAY.

&&

.NEAR TERM /TODAY AND TONIGHT/...
AS OF 330 PM WEDNESDAY...

THE FRONTAL ZONE...JUST NORTH OF RICHMOND VA...IS FORECAST TO SAG
SLOWLY SOUTHWARD TO NEAR THE NC/VA BORDER THIS EVENING. WEAK
S/W DISTURBANCES CRESTING THE FLAT RIDGE ALOFT HAS BEEN FEEDING
UPSTREAM CONVECTION OVER EAST KY AND SW VA... WITHIN THE WARM SECTOR
SOUTH OF THE FRONT. THESE STORMS ALONG WITH ANY REMNANT CONVECTIVE
OUTFLOW BOUNDARIES WILL BRING THE HIGHEST CHANCE OF POPS
TO THE NORTHERN PIEDMONT/COASTAL PLAIN THIS AFTERNOON AND EVENING.

DEEP LAYER SHEAR 20-30KTS...STRONGEST INVOF THE FRONT...WILL BE
SUFFICIENT TO SUPPORT ISOLATED HAIL AND/OR DAMAGING WIND GUSTS.

GIVEN THE POTENTIAL FOR SOME WEAK SHORTWAVE DISTURBANCES TO EJECT
EASTWARD DOWNSTREAM OF THE NEGATIVELY-TILTED SHORTWAVE TROUGH
LIFTING SLOWLY NORTHWARD ACROSS THE CENTRAL PLAINS...A CHANCE OF
SHOWERS AND AND THUNDERSTORMS WILL BE POSSIBLE ANYWHERE OVERNIGHT.

LOWS WEDNESDAY NIGHT RANGING FROM NEAR 60 NORTH TO MID 60S SOUTH.


&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 330 PM WEDNESDAY...

UPPER LOW OVER THE MID-UPPER MS VALLEY AT THE START OF THE PERIOD
WILL CONTINUE TO SHEAR AND WEAKEN AS IT MOVES EWD INTO THE MEAN
RIDGE POSITION ACROSS THE OH VALLEY/LOWER GREAT LAKES REGION ON
THURSDAY. ASSOCIATED WEAK SURFACE WAVE AND SFC COLD FRONT WILL MOVE
INTO THE REGION LATE THURSDAY/THURSDAY EVENING...WHERE IT WILL
INTERSECT THE STALLED FRONT IN PLACE ACROSS CENTRAL NC.

SEVERAL CONVECTIVE OUTFLOW BOUNDARIES FROM TONIGHTS STORMS ARE
LIKELY TO EXIST TO START THE DAY...WITH SCATTERED/PARTIAL BREAKS IN
THE LOW TO MID-LEVEL CLOUD COVER ALSO LIKELY TO SET UP A THERMAL
MOISTURE BOUNDARY(TMB)ACROSS THE AREA. SO FOR THE SECOND CONSECUTIVE
DAY...EXPECT MESOSCALE FEATURES TO PLAY A LARGE ROLE IN CONVECTIVE
EVOLUTION ACROSS CENTRAL NC.

NEVERTHELESS DAYTIME HEATING WITHIN THE WARM SECTOR...SOUTH OF THE
STALLED FRONT WILL RESULT IN MODERATE DESTABILIZATION OF 1000-
2000J/KG MLCAPE. WESTERLY H5 FLOW STRENGTHENS A BIT...WHICH WILL
IMPROVE BULK SHEAR VALUES TO 30 TO 35KTS...FAVORABLE FOR MULTICELLS
WITH ONE OR TWO SEVERE CLUSTERS POSSIBLE. MAIN THREAT WILL DAMAGING
THUNDERSTORM WIND GUSTS AND LARGE HAIL. AS THE FRONT MOVES INTO THE
AREA FROM THE WEST LATE EVENING/OVERNIGHT...THE STORMS SHOULD BEGIN
TO PUSH EAST AND OUT OF THE AREA.

HIGHS IN THE UPPER 70S NORTH TO MID 80S SOUTH. LOWS THURSDAY NIGHT
IN THE UPPER 50S/NEAR 60 NORTH TO MID 60S SE.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM WEDNESDAY...

A BROAD UPPER LEVEL TROUGH WILL COVER THE COUNTRY AT THE BEGINNING
OF THE PERIOD. A SERIES OF S/WS IN THE CYCLONIC FLOW WILL CAUSE
BOUTS OF UNSETTLED WEATHER TO CENTRAL NC. THE FIRST MINOR S/W WILL
CROSS NEAR OR NORTH OF OUR REGION FRIDAY AFTERNOON-EVENING. THE COOL
POOL ALOFT ASSOCIATED WITH THIS FEATURE COUPLED WITH AFTERNOON
HEATING AND RESIDUAL MOISTURE SHOULD TRIGGER A FEW SHOWERS/ISOLATED
T-STORMS...PRIMARILY OVER OUR NE PIEDMONT/NORTHERN COASTAL PLAIN
COUNTIES LATE FRIDAY-FRIDAY EVENING. WEAK HIGH PRESSURE WILL EXTEND
ACROSS THE REGION SATURDAY BUT QUICKLY SCOOT EAST BY SATURDAY
EVENING. THE RETURN FLOW ON THE BACKSIDE OF THE HIGH IN CONJUNCTION
WITH AN APPROACHING S/W TRAVERSING THE DEEP SOUTH/TN VALLEY SHOULD
ENHANCE LOW LEVEL MOISTURE RETURN...LEADING TO AREAS OF RAIN
BREAKING OUT OVER OUR REGION BY SUNDAY. THE SFC PRESSURE PATTERN
SUPPORTS THE POTENTIAL FOR A HYBRID/INSITU COLD AIR DAMMING
EVENT...SUGGESTING TEMPS WELL BE LOW NORMAL IF THE RAIN DEVELOPS.

EARLY NEXT WEEK...MODELS ADVERTISING A PATTERN AMPLIFICATION WITH A
WESTERN U.S. RIDGE AND EASTERN US.S TROUGH. DISTURBANCES IN THE
AMPLIFYING FLOW WILL CONTINUE TO BRING PERIODS OF UNSETTLED WEATHER
THROUGH MID WEEK. TEMPERATURES ON AVERAGE WILL BE A LITTLE SHY OF
NORMAL EARLY NEXT WEEK.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 136 PM WEDNESDAY...

24-HOUR TAF PERIOD: A COLD FRONT OVER CENTRAL/SOUTHERN VIRGINIA WILL
SAG SLOWLY SOUTH TOWARDS THE NC/VA STATE LINE THIS EVENING.
WEAK DISTURBANCES ALOFT MOVING ATOP THE LOW-LEVEL FRONTAL ZONE WILL
SUPPORT SCATTERED SHOWERS AND STORMS...MAINLY ACROSS THE NORTHERN
PIEDMONT AND COASTAL PLAIN THIS AFTERNOON AND EVENING.
KINT...KGSO...KRWI...AND KRDU HAVE THE BEST CHANCES OF SEEING
SUB-VFR CONDITIONS IN ASSOCIATION WITH THIS CONVECTION...WITH
LESSER CHANCES AT KFAY.

WITH THE STALLED FRONT NEARBY AND CONTINUED POTENTIAL TO SEE
WEAK DISTURBANCES TRACKING THROUGH THE REGION...ISOLATED
SHOWERS TO SMALL CHANCE POPS WILL CONTINUE OVERNIGHT...ESPECIALLY
ACROSS THE NORTH. CANNOT RULE OUT SOME PRE-DAWN FOG/STRATUS
THURSDAY MORNING...ESPECIALLY IN AREAS THAT RECEIVE HEAVY
RAINFALL.

SHOWERS AND THUNDERSTORMS AND ASSOCIATED RESTRICTIONS SHOULD BE MORE
WIDESPREAD THURSDAY AFTERNOON AND EVENING AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST.

LOOKING AHEAD: DRY CONDITIONS ARE EXPECTED FRIDAY AND SATURDAY
...BEFORE UNSETTLED WEATHER AND POSSIBLE RESTRICTIONS RETURN FROM
THE WEST SUNDAY THROUGH MONDAY FROM POTENTIAL CAD.

&&

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

&&

$$

SYNOPSIS...VINCENT/BADGETT
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...WSS
AVIATION...CBL


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