Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 281140
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
640 AM EST FRI NOV 28 2014

.SYNOPSIS...
HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE EAST COAST FROM
TODAY INTO TONIGHT, BEFORE MOVING TO THE SOUTH AND EAST SATURDAY
INTO SATURDAY NIGHT. A WARM FRONT MAY LIFT NORTH OF THE AREA
SATURDAY NIGHT INTO SUNDAY. A COLD FRONT IS EXPECTED TO SAG DOWN
ACROSS THE AREA SUNDAY NIGHT, BEFORE SLOWLY MOVING THROUGH THE
AREA MONDAY INTO MONDAY NIGHT. HIGH PRESSURE WILL THEN BRIEFLY
RETURN TO THE NORTHEAST FOR TUESDAY, FOLLOWED BY ANOTHER FRONTAL
SYSTEM AROUND WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A MID LEVEL SHORT WAVE TROUGH WAS PASSING OVERHEAD EARLY THIS
MORNING. THE FEATURE WILL MOVE OUT TO SEA.

CLOUDS AND SCATTERED SNOW SHOWERS AND FLURRIES WILL LINGER IN OUR
NORTHERN COUNTIES EARLY THIS MORNING IN THE DEVELOPING NORTHWEST
FLOW. A FEW TENTHS OF AN INCH OF NEW SNOW IS POSSIBLE, MAINLY IN
THE ELEVATED TERRAIN. OTHERWISE, WE ARE ANTICIPATING A MOSTLY
SUNNY SKY FOR TODAY AS DRY AIR BUILDS INTO OUR REGION. HIGH
CLOUDS MAY BEGIN TO OVERSPREAD OUR REGION FROM THE NORTHWEST
DURING THE AFTERNOON.

A GUSTY NORTHWEST WIND IS EXPECTED TO DEVELOP THIS MORNING AS THE
SHORT WAVE MOVES FARTHER TO OUR EAST. WE ARE FORECASTING WIND
SPEEDS AROUND 10 TO 15 MPH WITH GUSTS INTO THE 20S. MAXIMUM
TEMPERATURES SHOULD RANGE FROM THE UPPER 20S IN THE POCONOS TO
AROUND 40 DEGREES IN FAR SOUTHERN NEW JERSEY AND IN SOUTHERN
DELAWARE.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
HIGH CLOUDS WILL CONTINUE TO BUILD OVERHEAD THIS EVENING. WARM
ADVECTION IS FORECAST TO BEGIN OVER OUR REGION AS THE SURFACE
RIDGE PASSES OFF THE COAST. WE ARE ANTICIPATING MID LEVEL CLOUDS
TO DEVELOP IN THE ISENTROPIC LIFT. CEILINGS ARE EXPECTED TO LOWER
GRADUALLY LATE TONIGHT AND WE MAY SEE SOME LIGHT SNOW SHOWERS POKE
INTO OUR FORECAST AREA FROM THE WEST. ONLY A VERY LIGHT
ACCUMULATION IS ANTICIPATED WITH THE BEST CHANCE IN OUR FORECAST
AREA BEING IN EASTERN PENNSYLVANIA.

THE WIND IS EXPECTED TO BECOME LIGHT AND VARIABLE. FAIRLY GOOD
RADIATING CONDITIONS MAY BE PRESENT DURING THE EVENING AND
TEMPERATURES ARE FORECAST TO FALL INTO THE TEENS IN OUR NORTHERN
COUNTIES AND INTO THE 20S ELSEWHERE OVERNIGHT.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
OVERALL LOOKS LIKE A FAIRLY BENIGN PATTERN FOR THE MID-ATLANTIC
REGION OVER THE NEXT FEW DAYS...WITH NO BIG STORMS ON THE HORIZON
AND TEMPS GENERALLY WITHIN A FEW DEGREES OF NORMAL. THE FLOW ALOFT
IS MAINLY ZONAL OVR THE NRN US WITH A COUPLE OF SHRTWV TROFS MOVG
THROUGH ON MON AND AGAIN AROUND WED/THU. THE LATTER ONE IS FCST TO
DIG A LITTLER DEEPER OVER THE ERN US AND HAS A BETTER CHC TO
PRODUCE SOME LIGHT PRECIP. THE BEST ASSOCD FORCING FOR UVV REMAINS
TO OUR NORTH AND MOISTURE SEEMS RATHER LIMITED.

FOR SATURDAY...THE CURRENT COLD AIR MASS WILL BE LIFTING AWAY TO
THE NE AND RESULTING WAA WILL PRODUCE CLOUDS AND POSSIBLY SOME
LIGHT SNOW IN THE MORNING...MAINLY N OF PHL. AS HIGH PRES MOVES
OFF THE COAST...WINDS BECOME SWLY AND CONTINUE THRU SUN AND MON
AHEAD OF A COLD FRONT APPROACHING FROM THE NW. MAX TEMPS ON
SUN/MON SHOULD BE A FEW DEGS ABOVE NORMAL. ATTM IT LOOKS LIKE THE
FROPA WOULD BE SOMETIME AROUND MIDDAY MONDAY. THE FCST HAS CHC
POPS FOR MON/MON NIGHT WITH POSSIBLY SOME LIGHT SNOW IN CAA BEHIND
THE FRONT.

HIGH PRES MOVES BY RATHER QUICKLY TO THE NORTH ON TUE...FOLLOWED
BY ANOTHER FRONTAL SYSTEM ON WED. THIS ONE SEEMS TO HAVE A
SLIGHTLY BETTER FORCING AND MOISTURE CONNECTION AND POPS ARE
SLIGHTLY HIGHER FOR WED THAN MON. HWVR THERE IS A LOT OF
UNCERTAINTY THAT FAR OUT. ATTM IT LOOKS LIKE TEMPS SHOULD BE WARM
ENOUGH FOR MOSTLY RAIN.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MAINLY VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. EARLY
MORNING CLOUDS SHOULD BE FOLLOWED BY CLEARING FOR THE DAYLIGHT
HOURS. INCREASING AND LOWERING CLOUDS ARE EXPECTED FOR TONIGHT.
THERE IS A CHANCE OF LIGHT SNOW SHOWERS AND FLURRIES LATE TONIGHT,
ESPECIALLY AROUND KRDG AND KABE WHERE CONDITIONS MAY LOWER BRIEFLY
INTO THE MVFR RANGE.

A WEST NORTHWEST WIND AROUND 5 TO 10 KNOTS IS FORECAST FOR THE
EARLY MORNING. THE WIND SPEEDS SHOULD INCREASE TO 8 TO 12 KNOTS
DURING THE DAYLIGHT HOURS WITH GUSTS NEAR 20 KNOTS. THE WIND IS
EXPECTED TO BECOME LIGHT AND VARIABLE TONIGHT AS HIGH PRESSURE
BUILDS ACROSS OUR REGION.

OUTLOOK...
SATURDAY-MONDAY...MOSTLY VFR. WIND GUSTS 15-20 KNOTS EACH DAY;
SOUTHWEST SATURDAY & SUNDAY, BECOMING NORTHWEST ON MONDAY.

MONDAY NIGHT...CHANCE OF RAIN OR SNOW SHOWERS. GENERALLY VFR
CONDS BUT TEMPORARILY LOWER IN PRECIPITATION. GUSTY NORTHWEST
WINDS AROUND 20 KNOTS POSSIBLE.

TUESDAY...MOSTLY VFR WITH NORTH WINDS.

&&

.MARINE...
A MID LEVEL SHORT WAVE TROUGH WAS PASSING OVERHEAD EARLY THIS
MORNING. THE WEST NORTHWEST WIND WILL INCREASE IN ITS WAKE AND
WIND GUSTS AROUND 25 OR 30 KNOTS ARE POSSIBLE ON OUR COASTAL
WATERS, INCLUDING ON DELAWARE BAY, FOR MUCH OF THE DAY. AS A
RESULT, A SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 600 PM.

HIGH PRESSURE IS EXPECTED TO BUILD OVER OUR REGION FROM THE WEST
FOR TONIGHT AND WIND SPEEDS WILL LIKELY DIMINISH.

OUTLOOK...
SATURDAY-SUNDAY...SUB-SMALL CRAFT ADVISORY CONDITIONS EXPECTED AS
THE CENTER OF HIGH PRESSURE MOVES OUT OVER THE WATERS.

MONDAY-MONDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS REMAIN
POSSIBLE BEHIND THE COLD FRONT THAT MOVES ACROSS THE AREA.

TUESDAY...SUB-SMALL CRAFT ADVISORY CONDITIONS EXPECTED AS HIGH
PRESSURE AFFECTS THE WATERS.

&&

.CLIMATE...
WITH THANKSGIVING UPON US AND METEOROLOGICAL WINTER KNOCKING ON
OUR DOOR, ITS OUR ANNUAL LOOK TO SEE HOW PAST WINTERS HAVE FARED
BASED ON PRECEDING FALL PATTERNS AND TRENDS.

OUR FORAY LAST FALL ABOUT THE WINTER OF 2013-14 WAS AN
UNMITIGATED BUST AS THE NEGATIVE EASTERN PACIFIC OSCILLATION
PATTERN (EPO) TOOK HOLD IN NOVEMBER AND NEVER LET GO THE ENTIRE
WINTER. WHILE THE COLDER NOVEMBER TRENDED DOWN OUR WINTER
TEMPERATURE ANALOGS TO ABOUT NORMAL, IT WAS NOWHERE NEAR ENOUGH.
IT WAS ALSO ONLY THE SIXTH TIME (OUT OF FORTY SIX OCCURRENCES)
THAT A BOTTOM THIRD WINTER FOLLOWED A WARM OCTOBER.

ONCE AGAIN WE ARE HEADING INTO THIS WINTER WITH A RARER
COMBINATION OF A WARM OCTOBER AND COLDER NOVEMBER JUST LIKE THE
TWO PREVIOUS AUTUMNS.

IN TERMS OF ENSO, THE LATEST CONSENSUS OF ALL DYNAMICAL AND
STATISTICAL MODELS FOR THE WINTER SEASON IS FOR A WEAK EL NINO TO
OCCUR. OF LATE THE EL NINO HAS LOOKED HEALTHIER AS A KELVIN WAVE
AND A CURRENTLY ROBUST MJO CYCLE HAVE/WILL HELP BOOST SEA SURFACE
TEMPERATURE ANOMALIES (SSTA). AS CPC HAS STATED, THERE IS STILL A
SSTA AND ATMOSPHERIC RESPONSE DISCONNECT THAT EXISTS. THE LATEST
GLOBAL WIND OSCILLATION READINGS, OUR ATMOSPHERE IS STILL IN AN
ENSO NEUTRAL STATE EVEN IF WATER EASTERN TROPICAL PACIFIC
TEMPERATURE ANOMALIES HAVE BECOME WARMER.

WEAK EL NINOS SINCE 1950 IN PHILADELPHIA HAVE HAD AN AVERAGE
TEMPERATURE OF 33.2 DEGREES AND AVERAGE SNOWFALL OF 21.8 INCHES.
WEAK EL NINOS, LIKE MOST NON-UBER EL NINOS, FAVOR HAVING MORE
MAJOR SNOW STORMS THAN THE CLIMATOLOGICAL AVERAGE. IN THE TEN WEAK
EL NINOS SINCE 1950, PHILADELPHIA HAS HAD EIGHT SNOWFALL EVENTS OF
SIX INCHES OR MORE, FOUR OF WHICH WERE TEN INCHES OR MORE. THE
MOST COMMON MONTH FOR MAJOR SNOWS DURING WEAK EL NINOS IS JANUARY,
BUT THEY HAVE OCCURRED IN EVERY MONTH FROM NOVEMBER THROUGH MARCH.

LOOKING AT THE MIDDLE AND HIGH LATITUDES, ONCE AGAIN SNOW
COVERAGE IN EURASIA WAS OFF TO THE RACES IN SEPTEMBER AND OCTOBER,
EVEN FASTER THAN AUTUMN OF 2013. OCTOBER 2014 ONLY TRAILED OCTOBER
1976 FOR TOTAL SNOW COVERAGE. IN THE SATELLITE ERA WHEN BOTH
SEPTEMBER AND OCTOBER HAVE HAD ABOVE AVERAGE SNOW COVERAGE, 64
PERCENT OF THE ENSUING PHILADELPHIA WINTERS HAVE BEEN SNOWIER THAN
THE CURRENT AVERAGE AND HAD A 50/50 SPLIT WITH TEMPERATURES BEING
EITHER ABOVE OR BELOW NORMAL. WHILE 64 PERCENT MAY NOT SOUND
DEFINITIVE, SNOWFALL IS NOT A NORMAL DISTRIBUTION BECAUSE SEASONS
LIKE 2013-14 SKEW UPWARD THE STATISTICAL AVERAGE. SINCE 1967 (THE
START OF THE SATELLITE ERA AND OUR LOOK AT THE DR. JUDAH COHEN
STUDY) ONLY 1 IN 3 WINTERS HAS HAD ABOVE AVERAGE SNOWFALL. THE
STATISTICAL MEDIAN FOR SNOWFALL IN PHILADELPHIA SINCE 1967 IS
ABOUT 18 INCHES.

BEYOND SIBERIA, THE ARCTIC OSCILLATION AVERAGED NEGATIVE DURING
THE MONTH OF OCTOBER. WHEN IT HAS, 70 PERCENT OF ENSUING WINTERS
HAS AVERAGED NEGATIVE. THANK-YOU METEOROLOGIST MATT LANZA FOR THIS
INFORMATION. ANOTHER PHENOMENON THAT FAVORS A NEGATIVE ARCTIC
OSCILLATION FOR THIS UPCOMING WINTER IS THAT WE ARE IN THE
EASTERLY PHASE OF THE QUASI-BIANNUAL OSCILLATION STRATOSPHERIC
WINDS OVER THE TROPICS. WHEN WE ARE IN THIS PHASE, HISTORICALLY WE
HAVE HAD MORE SUDDEN STRATOSPHERIC WARMING EVENTS WHICH OFTEN
SPLITS AND DISPLACES EVERYBODY`S FAVORITE POLAR VORTEX FROM NEAR
THE NORTH POLE. THERE IS NO GUARANTEE THE WESTERN HEMISPHERE WOULD
BE THE SO CALLED BENEFICIARY OF THIS ARCTIC DISPLACEMENT, BUT A
HIGHER CHANCE EXISTS THIS WINTER VS NO CHANCE AT ALL.

THE ARCTIC OSCILLATION`S COUSIN, THE NORTH ATLANTIC OSCILLATION
(NAO), WE HAVE SEEN BEEN THE DRIVER (WINTER OF 2010-11) OR THE
CRICKET CHIRPING (LAST WINTER) RECENTLY. UNFORTUNATELY THIS
IMPORTANT TELECONNECTION INDEX IS TOUGH TO OUTLOOK MORE THAN WEEKS
IN ADVANCE. WHILE THE ARCTIC OSCILLATION AND NORTH ATLANTIC
OSCILLATION NORMALLY WORK IN TANDEM, ITS NOT ALWAYS THE CASE.
SINCE 1950, 60 PERCENT OF ALL WINTERS HAVE AVERAGED A NEGATIVE
ARCTIC OSCILLATION, BUT ONLY 42 PERCENT OF ALL WINTERS HAVE
AVERAGED A NEGATIVE NORTH ATLANTIC OSCILLATION. THE LATE JACK
ORDILLE POINTED US TO A RESEARCH PAPER USING NEWFOUNDLAND REGION
SPRING-SUMMER SEA SURFACE TEMPERATURE ANOMALIES AS A PREDICTOR OF
THE NAO FOR THE ENSUING WINTER. IT HAS WORKED WELL THE LAST COUPLE
OF WINTERS (HERE COMES THE JINX) AND IT FAVORS A NEGATIVE NAO FOR
THIS UPCOMING WINTER.

THIS BRINGS US TO OUR LAST (BUT NOT LEAST) OSCILLATION INDEX, THE
PACIFIC DECADAL OSCILLATION (PDO). CURRENTLY THE OSCILLATION IS IN
TEXTBOOK POSITIVE POSITION. SO MUCH SO, THAT WHEN ITS BEEN THIS
POSITIVE DURING THE MONTH OF OCTOBER, IT HAS NEVER AVERAGED
NEGATIVE (HERE COMES ANOTHER ANNOUNCER`S JINX: 15 OF 15 TIMES
SINCE 1900) DURING THE UPCOMING WINTER. ELEVEN OF THOSE WINTERS
HAVE AVERAGED COLDER THAN THE CURRENT AVERAGE (AND AVERAGED AROUND
20 INCHES OF SNOW) IN PHILADELPHIA. HISTORICALLY ABOUT 2/3RDS OF
ALL WINTERS SINCE 1900 HAVE AVERAGED COLDER THAN NORMAL IN
PHILADELPHIA WHEN THE PDO HAS AVERAGED POSITIVE. IN FACT, THE
GREATEST POINT OF FAILURE WHEN WARM OCTOBERS HAVE NOT BEEN
FOLLOWED BY WARMER WINTERS HAS BEEN WHEN THE PDO HAS BEEN STRONGLY
POSITIVE IN THE AUTUMN.

LOCALLY, OF THE 46 WARMEST WINTERS IN PHILADELPHIA ON RECORD,
HALF OF THEM HAVE OCCURRED AFTER A WARM OCTOBER. GIVEN THE STATE
OF THE PDO, WE DONT HAVE A WARM FEELING ABOUT THAT THIS WINTER.
THIS NOVEMBER WILL END AGAIN CLOSE TO THE CUSP BETWEEN THE
UNSEASONABLY COLD AND NORMAL TERCILES. REGARDLESS THIS IS A RARER
OCCURRENCE AND A CONTRADICTION IN THE STUDY FIRST DONE IN WHICH
THE STRONGEST CORRELATOR FOR A WARM WINTER IS A WARM OCTOBER WHILE
THE STRONGEST CORRELATOR FOR A COLD WINTER IS A COLD NOVEMBER. IN
2012 OCTOBER WON, LAST YEAR NOVEMBER WON. UNLIKE THE LAST TWO
WINTERS, WE ARE EXPECTING A WEAK EL NINO AND NOT ENSO NEUTRAL
NEGATIVE. WHILE THE PACIFIC FAVORS COLD AGAIN, THE TYPE OF COLD
LOOKS DIFFERENT AS POSITIVE SEA SURFACE TEMPERATURE ANOMALIES ARE
FARTHER EAST THAN THEY WERE LAST AUTUMN.

SO HERE ARE OUR ANALOGS FOR THE UPCOMING WINTER. THEY ARE BASED
ON WARMER THAN CURRENT NORMAL OCTOBERS AND COLDER THAN CURRENT
NORMAL NOVEMBERS. THE ANALOGS ARE A COMBINATION OF MODERATE, WEAK
AND ENSO POSITIVE WINTERS. SEVEN OF THESE ALSO HAD POSITIVE PDO(S)
DURING THE WINTER, THE ONE EXCEPTION (1953-4) WE KEPT BECAUSE IT
WAS A WEAK EL NINO AND IT ALSO WAS A SNOWY NOVEMBER. AS ALWAYS
PAST PERFORMANCE MAY NOT BE AN INDICATOR OF FUTURE TRENDS....AND
NOW TO THE GREAT EIGHT:



SEASON         DEC      JAN      FEB    WINTER    SEASONAL   WINTER
               AVG      AVG      AVG      AVG     SNOWFALL   PCPN


1905-06        39.2     39.4     33.6     37.4       20.5    8.61
1914-15        33.3     36.6     38.6     36.2       32.5   19.64
1939-40        38.1     25.3     34.8     32.7       22.3    7.77
1941-42        38.3     30.5     30.8     33.2       10.3    9.24
1951-52        38.7     37.3     38.2     38.1       16.2   12.21
1953-54        39.4     31.7     41.7     37.6       22.6    7.58
1986-87        37.9     31.9     32.5     34.1       25.7   11.64
2002-03        35.4     28.6     29.9     31.3       46.3   11.02

AVG            37.5     32.7     35.0     35.1       24.6   11.59
1981-2010 NML  37.5     33.0     35.7     35.4       22.4    9.24

THE OFFICIAL CPC OUTLOOK FOR THE WINTER IS FOR EQUAL CHANCES OF
IT BEING EITHER WARMER OR COLDER THAN NORMAL AND A GREATER CHANCE
OF IT BEING WETTER THAN NORMAL.

WE HOPE EVERYONE HAD A GREAT THANKSGIVING AND WE HOPE YOU WILL
HAVE A HAPPY UPCOMING HOLIDAY SEASON. MAY THIS WINTER BE BEYOND
YOUR WILDEST EXPECTATIONS.

&&

.EQUIPMENT...
KDIX WSR-88D RADAR IS INOPERATIVE. TECHNICIANS HAVE BEEN NOTIFIED
AND WILL TROUBLESHOOT THE ISSUE. TPHL TDWR SHOULD PROVIDE
SUFFICIENT BACKUP RADAR COVERAGE.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ430-
     431-450>455.

&&

$$

SYNOPSIS...AMC
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...AMC
AVIATION...AMC/IOVINO
MARINE...AMC/IOVINO
CLIMATE...GIGI
EQUIPMENT...STAFF





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