River Flood Warning 23, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
209 PM EST TUE DEC 22 2015

.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT THROUGH TONIGHT...THEN BE OVERTAKEN BY A MARITIME WARM
FRONT THAT WILL SURGE ACROSS THE CAROLINAS AND VIRGINIA ON
WEDNESDAY. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM TUESDAY...

DEEP SOUTHWESTERLY FLOW CONTINUES THIS MORNING WITH STRONG
WARM/MOIST ADVECTION BETWEEN THE WESTERN ATLANTIC RIDGE AND THE
WESTERN US TROUGHINESS.  THE PRIMARY MOIST AXIS ASSOCIATED THE THIS
MORNING'S HEAVY RAIN IS SHIFTING EAST WITH THE DEPARTING LLJ...AND
DRIER AIR NOTED AT 700MB IS FILTERING IN FROM THE WEST.  RADAR
TRENDS HAVE BEEN FOR A FASTER EASTWARD PROGRESSION OF CONVECTIVE
ELEMENTS AND LESS POTENTIAL FOR FLOODING AS THE MORNING WEARS ON...WITH
MOST AREAS OUTSIDE OF THE ISOLATED CONVECTIVE CELLS REPORTING A
THIRD OF AN INCH OR SO OF RAIN IN AN HOUR.  THIS TREND WILL CONTINUE
AND MANY AREAS WEST OF US 1 SHOULD BE RAIN FREE THIS AFTERNOON.
EASTERN AREAS DON'T DRY OUT AS QUICKLY THIS AFTERNOON...AND A
CONTINUED STREAM OF LOW AMPLITUDE DISTURBANCES STREAMING FROM
NORTHWEST TO NORTHEAST COULD CONTINUE TO TRIGGER PERIODS OF
SHOWERS...AT LEAST ENOUGH SO TO CONTINUE CHANCE TO LIKELY POPS IN
THE COASTAL PLAIN.

OUTSIDE OF THE PRECIP...SOME FOG HAS BEEN DEVELOPING IN THE
FOOTHILLS AS THE DRIER AIR ALOFT MOVES IN. EXPECT THIS TO ME
TEMPORARY AS MIXING SHOULD PICK UP THIS AFTERNOON...SO WILL MONITOR
TRENDS FOR NOW AND HOLD OFF ON A DENSE FOG ADVISORY.  HIGHS WILL
RANGE FROM THE UPPER 50S NORTHWEST TO NEAR 70 SOUTHEAST. -22

THIS EVENING/TONIGHT: SHOULD SEE A LULL THIS EVENING AND THROUGH THE
FIRST HALF OF THE NIGHT WITH RAIN CHANCES QUICKLY RATCHETING UP
LATE...ESPECIALLY IN THE WEST AS NEXT STRONG SURGE OF GULF MOISTURE
SPREADS NORTH INTO THE AREA IN RESPONSE TO THE NEXT SHORTWAVE TROUGH
ROTATING THROUGH THE BASE OF THE UPPER TROUGH AXIS. MILD OVERNIGHT
LOWS IN THE UPPER 50S NORTHWEST TO LOWER/MID 60S SOUTHEAST.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...

AS OF 420 AM TUESDAY...

STRONG GULF MOISTURE TRANSPORT COURTESY OF A 50-60KT H8 LLJ...EAST
OF THE NEGATIVE-TILTED TROUGH LIFTING NEWD THROUGH THE MS VALLEY
WILL SUPPORT WIDESPREAD SHOWERS ALONG WITH THE CHANCE OF THUNDER ON
WEDNESDAY WITH THE POTENTIAL TO REALIZE WEAK TO POSSIBLY MODERATE
SURFACE BUOYANCY/DESTABILIZATION WEDNESDAY AFTERNOON
...ESPECIALLY ACROSS THE EASTERN HALF WHERE SFC DEWPOINTS WILL
LIKELY RISE INTO THE UPPER 60S/NEAR 70. WHILE CENTRAL NC WILL BE
REMOVED FROM THE BETTER UPPER FORCING...THE STRONG LOW-LEVEL
MOISTURE CONVERGENCE AND STRENGTHENING DIVERGENCE WITHIN THE RIGHT
ENTRANCE REGION OF THE STJ LIFTING THROUGH THE SOUTHERN APPALACHIANS
DURING FAVORABLE DIURNAL TIMING COULD SUPPORT A FEW STRONG TO SEVERE
STORMS BY THE LATE MORNING AND INTO THE AFTERNOON. HOWEVER AS WE SAW
LAST WEEK IN A SIMILAR EVENT...TIMING IS EVERYTHING AND IF THE
CONVECTION BLOWS IN AND EXITS THE AREA EARLY ENOUGH IN THE
DAY...THEN THE SEVERE POTENTIAL WILL BE NULL. THE MAIN THREAT COULD
END UP BEING SOME LOCALIZED/ISOLATED FLOODING WITH ANOTHER INCH
POSSIBLE. WILL CONTINUE TO MONITOR AND ADDRESS ANY POTENTIAL SEVERE
AND/OR FLOODING THREAT ACCORDINGLY...BUT AT THIS TIME BOTH APPEAR
LOW.

THE VERY WARM AND MOIST AIR WILL SUPPORT MILD TEMPERATURES IN THE
LOWER TO MID 70S ON WEDNESDAY WITH LOWS WEDNESDAY NIGHT STAYING IN
THE 60S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 200 PM TUESDAY...

THU AND THU NIGHT: STILL SOME DIFFERENCES IN THE MODELS WITH RESPECT
TO RAIN...THUS THERE IS STILL SOME UNCERTAINTY. HOWEVER...IT IS
LOOKING LIKE THURSDAY COULD BE RELATIVELY DRY...BUT WILL KEEP A
CHANCE OF SOME RAIN IN THE FORECAST. RAIN SHOULD NOT BE NEARLY AS
WIDESPREAD AS IN PRECEDING DAYS. BEST CHANCES FOR CONVECTION WILL
BE IN THE NORTHWEST...ESPECIALLY IN THE AFT/EVE AND INTO THE
OVERNIGHT. HIGHEST TEMPERATURES OF THE LONG TERM ARE STILL EXPECTED
ON THURSDAY AS THE SOUTHERLY WARM ADVECTION PEAKS. HIGHS IN THE LOW
TO MID 70S NW TO AROUND 80 DEGREES IN THE SE. LOWS GENERALLY IN THE
MID 60S.

FRI THROUGH SUN: AS OF THE LATEST MEDIUM RANGE MODEL RUNS...THIS
PERIOD WILL LIKELY BE DOMINATED BY SUB-TROPICAL RIDGING ALOFT OVER
THE SOUTHEAST U.S.. SOUTHERLY TO SOUTHWESTERLY RETURN FLOW AROUND
THE SURFACE HIGH WILL CONTINUE TO USHER WARM MOIST AIR INTO THE
REGION...RESULTING IN A VERY WARM AND MOIST PERIOD FOR THIS TIME OF
YEAR. THE OCCASIONAL UPPER LEVEL DISTURBANCE RIDING THE RIDGE MAY
GENERATING ENOUGH LIFT IN THE ANOMALOUSLY WARM MOIST AIRMASS TO KICK
OFF SOME SHOWERS...MAINLY IN THE AFT/EVE HOURS. THE GENERAL PRECIP
TREND FOR THIS PERIOD WILL BE CHARACTERIZED BY A LULL DURING THE
OVERNIGHT AND MORNING HOURS AND HIGHEST CHANCES DURING THE AFT/EVE.
THE INITIAL FRONTAL SURGE THAT WAS ORIGINALLY EXPECTED TO PUSH SOUTH
INTO THE AREA ON FRIDAY WILL LIKELY STAY WELL TO THE NORTH THROUGH
AT LEAST SUNDAY EVENING. LOWS THROUGH THE PERIOD WILL BE FAIRLY
CONSISTENT...AND WELL ABOVE NORMAL...IN THE MID 50S TO LOW 60S.
HIGHS WILL LIKELY FLUCTUATE A BIT MORE...BUT GENERALLY STAY BETWEEN
THE MID 60S AND UPPER 70S...WHICH IS 10-15 DEGREES ABOVE NORMAL FOR
LATE DECEMBER.

MONDAY AND MONDAY NIGHT...THE GFS AND ECMWF VARY ON WHETHER THEY
THINK A SECONDARY SURGE WILL PUSH FAR ENOUGH SOUTH TO MOVE INTO
CENTRAL NC FOR THE BEGINNING OF THE WEEK. WILL HOLD OFF ON MAKING
ANY DRASTIC CHANGES TO THE PREVIOUS FORECAST FOR EARLY NEXT WEEK
UNTIL THERE IS BETTER AGREEMENT ONE WAY OR THE OTHER.

&&

.CLIMATE...

HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.

DEC 24:       RECORD MAXIMUM   HIGH MINIMUM
GREENSBORO    71 (1964)        52 (1904)
RALEIGH       75 (1931)        59 (1891)
FAYETTEVILLE  78 (1931)        66 (1990)

DEC 25:       RECORD MAXIMUM   HIGH MINIMUM
GREENSBORO    74 (1955)        58 (1932)
RALEIGH       75 (1955)        63 (1932)
FAYETTEVILLE  79 (1932)        68 (1932)

&&

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

&&

SYNOPSIS...2
NEAR TERM...CBL/22
SHORT TERM...CBL
LONG TERM...10
AVIATION...CBL/22
CLIMATE...HARTFIELD/BLAES

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
1130 AM EST TUE DEC 22 2015

NCZ021-022-038-039-073-074-083-231630-
FORSYTH-GUILFORD-DAVIDSON-RANDOLPH-STANLY-MONTGOMERY-ANSON-
1130 AM EST TUE DEC 22 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

HEAVY RAIN IS EXPECTED TO SPREAD ACROSS WESTERN NORTH CAROLINA
LATE TONIGHT AND EARLY DURING THE DAY ON WEDNESDAY. WHILE THE
HEAVIEST RAINFALL WILL BE IN THE MOUNTAINS...ONE TO TWO INCHES OF
ADDITIONAL RAINFALL IS POSSIBLE IN THE WESTERN PIEDMONT...WHICH
MAY LEAD TO SOME RUNOFF PROBLEMS AND MINOR FLOODING IN URBAN AND
FLOOD PRONE AREAS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

HEAVY RAINFALL EARLY WEDNESDAY MAY LEAD TO SOME MINOR FLOODING
CONCERNS IN THE WESTERN PIEDMONT. OTHERWISE...HAZARDOUS WEATHER IS
NOT EXPECTED THROUGH THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ007>011-023>028-040>043-075>078-084>086-088-089-231630-
PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-ALAMANCE-ORANGE-DURHAM-
FRANKLIN-NASH-EDGECOMBE-CHATHAM-WAKE-JOHNSTON-WILSON-MOORE-LEE-
HARNETT-WAYNE-RICHMOND-SCOTLAND-HOKE-CUMBERLAND-SAMPSON-
1130 AM EST TUE DEC 22 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
912 AM EST TUE DEC 22 2015

NCZ042-043-078-221500-
JOHNSTON NC-WILSON NC-WAYNE NC-
912 AM EST TUE DEC 22 2015

...A HEAVY RAIN SHOWER WILL AFFECT PORTIONS OF SOUTHEASTERN
JOHNSTON...SOUTHWESTERN WILSON AND NORTHERN WAYNE COUNTIES UNTIL
1000 AM EST...

AT 909 AM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
HEAVY RAIN SHOWER NEAR SMITHFIELD...MOVING NORTHEAST AT 40 MPH.

WIND GUSTS UP TO 35 MPH AND A BRIEF TORRENTIAL DOWNPOUR WILL BE
POSSIBLE WITH THIS SHOWER.

LOCATIONS IMPACTED INCLUDE...
GOLDSBORO...SMITHFIELD...WILSON...FREMONT...MICRO...SELMA...FOUR
OAKS...PINE LEVEL...KENLY AND PRINCETON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LOCALLY HEAVY RAIN WILL QUICKLY REDUCE VISIBILITY AND RESULT IN
PONDING OF WATER ON ROADWAYS. DRIVERS ARE URGED TO SLOW DOWN AND USE
EXTRA CAUTION TO AVOID HYDROPLANING.

&&

LAT...LON 3535 7782 3529 7839 3551 7846 3580 7799
      3555 7782 3543 7783 3539 7780
TIME...MOT...LOC 1409Z 246DEG 35KT 3542 7834

22

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1032 AM EST TUE DEC 22 2015

NCZ021-022-038-039-221800-
FORSYTH-GUILFORD-DAVIDSON-RANDOLPH-
INCLUDING THE CITIES OF...WINSTON-SALEM...GREENSBORO...
HIGH POINT...LEXINGTON...THOMASVILLE...ASHEBORO...ARCHDALE...
TRINITY
1032 AM EST TUE DEC 22 2015

...AREAS OF DENSE FOG ACROSS THE WESTERN PIEDMONT THROUGH EARLY
AFTERNOON...

IN THE WAKE OF THE EARLY MORNING RAINFALL...AREAS OF FOG...SOME
LOCALLY DENSE...ARE DEVELOPING ACROSS PORTIONS OF THE WESTERN
PIEDMONT. VISIBILITY WILL BE REDUCED TO ONE QUARTER MILE OR LESS
IN SOME AREAS. MOTORISTS ARE URGED TO DRIVE WITH CAUTION AND BE
PREPARED FOR THE RAPIDLY CHANGING VISIBILITY.

A SOUTHERLY WIND IS EXPECTED TO SCOUR THE FOG BY EARLY
AFTERNOON...GREATLY IMPROVING VISIBILITIES.

22