Absolute Humidity Posted December 2, 2014 Share Posted December 2, 2014 Mount Holly, NJ Weather Forecast Office Winter Analogs for 2014-15 Weather.gov > Mount Holly, NJ > Winter Analogs for 2014-15 http://www.weather.gov/phi/AnalogsWinter14-15PHI PHILADELPHIA/MT HOLLY WINTER ANALOGS FOR 2014-2015 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 DON`T 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 Link to comment Share on other sites More sharing options...
JCT777 Posted December 2, 2014 Share Posted December 2, 2014 I remember the 2 most recent analog winters (1986-87, 2002-03) and both were great for snow lovers in my area (the NW suburbs did much better than the Philly airport in the winter of 1986-87, in large part due to the Feb 22/23 event). I'd take a repeat of either one any time. Link to comment Share on other sites More sharing options...
Absolute Humidity Posted December 2, 2014 Author Share Posted December 2, 2014 I remember the 2 most recent analog winters (1986-87, 2002-03) and both were great for snow lovers in my area (the NW suburbs did much better than the Philly airport in the winter of 1986-87, in large part due to the Feb 22/23 event). I'd take a repeat of either one any time. 1986 1987 was one of the best winters Monmouth County ever had. There were two MECS's and two SECS totaling over 60" in many areas. NYC on the on the other hand got less than half that. Link to comment Share on other sites More sharing options...
RedSky Posted December 2, 2014 Share Posted December 2, 2014 1987 was the best winter of the lame 80's 1983 had one good week the blizzard and a 5" snow. 80's were Link to comment Share on other sites More sharing options...
Violentweatherfan Posted December 2, 2014 Share Posted December 2, 2014 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. This made me chuckle. Very nice write up, and straight to the point without any "look at me" BS. Link to comment Share on other sites More sharing options...
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