Gigi's Analog Disco For Winter 2012-13 for Philly

[phlwx]

ITS THAT WONDERFUL TIME OF THE YEAR TO SPECULATE ON HOW THE UPCOMING

WINTER WILL BE. ITS JUST ABOUT A SLAM DUNK TO SAY WELL ITS GOING TO

BE SNOWIER AND COLDER THAN LAST WINTER AS LAST WINTER WAS ONE OF THE

WARMEST AND LEAST SNOWIEST ONES ON RECORD FOR PHILADELPHIA.

ITS NOW A HAT TRICK OF WINTERS ON HOW THE NORTH ATLANTIC OSCILLATION

(NAO) CAN THOROUGHLY TRUMP THE PACIFIC ENSO STATE. THE TWO

PREVIOUS WINTERS WERE BOTH MODERATE LA NINAS AND WERE NEARLY POLAR

OPPOSITES IN OUR AREA. UNFORTUNATELY THE NAO IS NOT AS WELL

OUTLOOKED AS IS THE TROPICAL PACIFIC.

STARTING WITH THE TROPICAL PACIFIC, THE EL NINO PROJECTIONS (AND

OBSERVED CONDITIONS TO BOOT) BY BOTH THE DYNAMICAL AND STATISTICAL

MODELS HAVE FADED IN THE LAST COUPLE OF MONTHS. THE MODEL CONSENSUS

FOR THIS UPCOMING WINTER IS FOR ENSO NEUTRAL POSITIVE.

CLIMATOLOGICALLY SPEAKING SINCE THE WINTER OF 1949-50, ENSO NEUTRAL

WINTERS IN PHILADELPHIA HAVE HAD AN AVERAGE TEMPERATURE OF 35.0F

(NORMAL 35.2F) AND 19.7 INCHES OF SNOW (NORMAL 22.4 INCHES). THE ONE

FACTOR THAT WE FIND INTERESTING IN ENSO NEUTRAL POSITIVE WINTERS IS

THE LACK OF LARGER SNOW EVENTS IN PHILADELPHIA. THERE HAS BEEN ONLY

TWO 6 INCH OR GREATER EVENTS (OUT OF SIX ENSO NEUTRAL POSITIVE

WINTERS) SINCE 1950. COMPARE THIS TO A WEAK EL NINO THAT HAS HAD

EIGHT (OUT OF TEN WINTERS) AND ENSO NEUTRAL NEGATIVE THAT HAS HAD

THIRTEEN (OUT OF FOURTEEN WINTERS). OF COURSE OF LATE THE SNOW

STORMS THAT HAVE AFFECTED OUR AREA HAVE BEEN MORE WHOPPERS THAN

DUDS. OF THE TWENTY-ONE TEN INCH OR GREATER EVENTS IN PHILADELPHIA

SINCE 1950, TWELVE OF THEM HAVE OCCURRED SINCE THE WINTER OF 1995-96

AND FIVE OF THE LAST SIX SNOWFALL EVENTS THAT HAVE CROSSED THE SIX

INCH THRESHOLD WERE TEN INCHES OR MORE.

AS FOR TRYING TO OUTLOOK THE NORTH ATLANTIC OSCILLATION WE HAVE

LOOKED AT APPROXIMATELY FIVE DIFFERENT METHODS THAT HAVE HAD SOME

DEGREE OF SUCCESS IN THE PAST. THE SCOREBOARD FOR THIS WINTER IS

THREE FOR NAO POSITIVE, ONE FOR NAO NEUTRAL AND ONE FOR NAO

NEGATIVE. BUT THAT LAST ONE HAS BEEN THE HOT OUTLOOK OF LATE AND

ONE COULD SAY HAS HAD STAYING POWER. THIS IS THE EXTENT OF EURASIAN

AND MORE SPECIFICALLY, IF WE COULD HAVE SEEN THE NUMBERS, THE

SIBERIAN SNOW EXTENT DURING THE MONTH OF OCTOBER. IT HAS BEEN

CORRECT THE LAST THREE WINTERS (GREATER THAN NORMAL SNOW COVER,

OVERALL NEGATIVE NAO). LOCALLY WE HAVE FOUND ITS A BETTER INDICATOR

OF SNOW THAN TEMPERATURES. SEASONAL SNOWFALL STATISTICALLY SPEAKING

IS NOT A NORMAL DISTRIBUTION, BUT A GAMMA DISTRIBUTION. THE SNOWY

WINTERS SKEW THE AVERAGE HIGHER. THE MOST LIKELY OUTCOME FOR ANY

GIVEN WINTER IS BELOW AVERAGE SNOWFALL. SINCE SNOWCOVER CAN BE

MAPPED, THERE IS A 33 PERCENT CHANCE OF ANY GIVEN WINTER BEING ABOVE

THE CURRENT NORMAL. BUT WHEN EURASIAN SNOW COVER IS GREATER THAN

NORMAL IN OCTOBER, THE PAST PERCENTAGE HAS INCREASED TO 50 PERCENT.

IF IT WAS BELOW NORMAL, LIKE LAST WINTER, ITS BEEN ONLY 18 PERCENT.

MY COLLEAGUE FROM ACROSS THE AISLE HAS TOLD US THAT FROM A

STATISTICAL POINT, THE EURASIAN OCTOBER SNOW COVER DOES NOT ADD

MUCH CONFIDENCE BEYOND USING WHAT WE HAVE ALREADY BEEN DOING FOR

SEVERAL YEARS: LOOKING AT THE LOCAL OCTOBER AND NOVEMBER

TEMPERATURES. IN A CIRCUITOUS ROUTE (ARRIVING WITH THE SAME

OUTCOME?), THE SNOW COVER INFLUENCES THE PATTERNS WHICH IN TURN

INFLUENCES THE TEMPERATURES. WE HAD A WARM OCTOBER AND FOR THE FIRST

TIME SINCE 1996 WE BELIEVE WILL HAVE A COLD (LOWEST THIRD) NOVEMBER.

THIS TOP THIRD, BOTTOM THIRD COMBO IS NOT COMMON AT ALL IN ANY ENSO

REGIME. SO MUCH SO, FOR OUR ANALOG SERIES TO GET SIX PAST SEASONS,

WE HAD TO INCLUDE A COUPLE OF WEAK EL NINO WINTERS AND ONE ENSO

NEUTRAL NEGATIVE WINTER. ALL HAD WARM OCTOBERS AND COLDER THAN

CURRENT NORMAL NOVEMBERS TO FIT THE TEMPERATURE SEQUENCE. ONLY

1959-60 HAD A LOWEST THIRD (COLD) NOVEMBER. AFTER ALL OF THE

EURASIAN SNOW COVER DISCUSSION IT IS IRONIC THAT ALL OF THESE

ANALOGS OCCURRED PRIOR TO SATELLITE DATA BEING AVAILABLE TO GATHER

THESE STATISTICS. SO HERE ARE OUR CHEAPER BY THE HALF DOZEN ANALOGS

FOR THIS UPCOMING WINTER FOR PHILADELPHIA. THEIR MILEAGE MAY VARY:

SEASON DEC JAN FEB WINTER SEASONAL WINTER

AVG AVG AVG AVG SNOWFALL* PCPN

1914-5 33.3 36.6 38.8 36.2 32.3 19.64

1919-0 32.5 26.8 31.4 30.2 23.2 9.71

1932-3 40.4 42.6 36.7 39.9 22.0 8.98

1941-2 38.3 30.5 30.8 33.2 10.3 9.24

1953-4* 39.4 31.7 41.2 37.4 22.6* 7.58

1959-0 38.2 34.2 35.4 35.9 21.8 10.17

AVG 37.0 33.7 35.7 35.5 22.0 10.89

1981-2010 NML 37.5 33.0 35.7 35.4 22.4 9.24

* THIS INCLUDES THE NOVEMBER SNOW THAT SEASON. THE OFFICIAL CPC OUTLOOK FOR THE WINTER IS FOR EQUAL CHANCES OF IT IT BEING EITHER WARMER OR COLDER THAN NORMAL AND EITHER WETTER OR DRIER THAN NORMAL. WE WANT TO WISH EVERYONE A VERY HAPPY AND HEALTHY WINTER SEASON AND PLEASE USE YOUR SNOW THROWERS AS MUCH OR AS LITTLE AS YOU DESIRE.

[SP]

Great write up Tony!! Interesting to understand the process. I like the number 22

[Parsley]

Amazing stuff.

[Absolute Humidity]

Pretty cool. Already past the half way point. For Philly anyway.

[chubbs]

Nice write-up. I'd take 59/60 again. Had a snowy March and was followed by great winter.

[easternsnowman]

I noticed it shows normal snowfall for philly...I agree, but I think this year the burbs will do much better than the city. Temperature wise it shows december slighly above normal and january and feb normal which makes sense and is close to glenn hurricane's ideas. I feel that the snowcover idea is more valid than the october temps especially since november is well below normal especially considering recent trends.

[ChescoWx]

Using Tony's analogs - here is how it plays with historical records here in Chester County PA. A below average snowfall season....

1914-15 - 31.6"

1919-20 - 44.3"

1932-33 - 23.7"

1941-42 - 9.0"

1953-54 - 25.0"

1959-60 - 33.1"

6 Year Avg of these = 27.8" Average Chester County Annual Snowfall (33.4") and (36.7" East Nantmeal Twp)

[easternsnowman]

Using Tony's analogs - here is how it plays with historical records here in Chester County PA. A below average snowfall season....

1914-15 - 31.6"

1919-20 - 44.3"

1932-33 - 23.7"

1941-42 - 9.0"

1953-54 - 25.0"

1959-60 - 33.1"

6 Year Avg of these = 27.8" Average Chester County Annual Snowfall (33.4") and (36.7" East Nantmeal Twp)

Based on that philly will be average and chester county below. I still think based on trends that philly does get average snowfall and chester county will get above average....thinking about 40 to 45 inches for the year.

[Rainshadow]

Thank-you for the kind words.

[SP]

Thank-you for the kind words.

Tony

Hope you are going to take advantage of the "Winter rules" and "Spring Temps" next week!!

I plan too

[Rainshadow]

Tony

Hope you are going to take advantage of the "Winter rules" and "Spring Temps" next week!!

I plan too

My off days and the warm weather days are not coinciding. I don't mind golfing when its colder, as long as its not windy.

[uncle W]

ITS THAT WONDERFUL TIME OF THE YEAR TO SPECULATE ON HOW THE UPCOMING

WINTER WILL BE. ITS JUST ABOUT A SLAM DUNK TO SAY WELL ITS GOING TO

BE SNOWIER AND COLDER THAN LAST WINTER AS LAST WINTER WAS ONE OF THE

WARMEST AND LEAST SNOWIEST ONES ON RECORD FOR PHILADELPHIA.

ITS NOW A HAT TRICK OF WINTERS ON HOW THE NORTH ATLANTIC OSCILLATION

(NAO) CAN THOROUGHLY TRUMP THE PACIFIC ENSO STATE. THE TWO

PREVIOUS WINTERS WERE BOTH MODERATE LA NINAS AND WERE NEARLY POLAR

OPPOSITES IN OUR AREA. UNFORTUNATELY THE NAO IS NOT AS WELL

OUTLOOKED AS IS THE TROPICAL PACIFIC.

STARTING WITH THE TROPICAL PACIFIC, THE EL NINO PROJECTIONS (AND

OBSERVED CONDITIONS TO BOOT) BY BOTH THE DYNAMICAL AND STATISTICAL

MODELS HAVE FADED IN THE LAST COUPLE OF MONTHS. THE MODEL CONSENSUS

FOR THIS UPCOMING WINTER IS FOR ENSO NEUTRAL POSITIVE.

CLIMATOLOGICALLY SPEAKING SINCE THE WINTER OF 1949-50, ENSO NEUTRAL

WINTERS IN PHILADELPHIA HAVE HAD AN AVERAGE TEMPERATURE OF 35.0F

(NORMAL 35.2F) AND 19.7 INCHES OF SNOW (NORMAL 22.4 INCHES). THE ONE

FACTOR THAT WE FIND INTERESTING IN ENSO NEUTRAL POSITIVE WINTERS IS

THE LACK OF LARGER SNOW EVENTS IN PHILADELPHIA. THERE HAS BEEN ONLY

TWO 6 INCH OR GREATER EVENTS (OUT OF SIX ENSO NEUTRAL POSITIVE

WINTERS) SINCE 1950. COMPARE THIS TO A WEAK EL NINO THAT HAS HAD

EIGHT (OUT OF TEN WINTERS) AND ENSO NEUTRAL NEGATIVE THAT HAS HAD

THIRTEEN (OUT OF FOURTEEN WINTERS). OF COURSE OF LATE THE SNOW

STORMS THAT HAVE AFFECTED OUR AREA HAVE BEEN MORE WHOPPERS THAN

DUDS. OF THE TWENTY-ONE TEN INCH OR GREATER EVENTS IN PHILADELPHIA

SINCE 1950, TWELVE OF THEM HAVE OCCURRED SINCE THE WINTER OF 1995-96

AND FIVE OF THE LAST SIX SNOWFALL EVENTS THAT HAVE CROSSED THE SIX

INCH THRESHOLD WERE TEN INCHES OR MORE.

AS FOR TRYING TO OUTLOOK THE NORTH ATLANTIC OSCILLATION WE HAVE

LOOKED AT APPROXIMATELY FIVE DIFFERENT METHODS THAT HAVE HAD SOME

DEGREE OF SUCCESS IN THE PAST. THE SCOREBOARD FOR THIS WINTER IS

THREE FOR NAO POSITIVE, ONE FOR NAO NEUTRAL AND ONE FOR NAO

NEGATIVE. BUT THAT LAST ONE HAS BEEN THE HOT OUTLOOK OF LATE AND

ONE COULD SAY HAS HAD STAYING POWER. THIS IS THE EXTENT OF EURASIAN

AND MORE SPECIFICALLY, IF WE COULD HAVE SEEN THE NUMBERS, THE

SIBERIAN SNOW EXTENT DURING THE MONTH OF OCTOBER. IT HAS BEEN

CORRECT THE LAST THREE WINTERS (GREATER THAN NORMAL SNOW COVER,

OVERALL NEGATIVE NAO). LOCALLY WE HAVE FOUND ITS A BETTER INDICATOR

OF SNOW THAN TEMPERATURES. SEASONAL SNOWFALL STATISTICALLY SPEAKING

IS NOT A NORMAL DISTRIBUTION, BUT A GAMMA DISTRIBUTION. THE SNOWY

WINTERS SKEW THE AVERAGE HIGHER. THE MOST LIKELY OUTCOME FOR ANY

GIVEN WINTER IS BELOW AVERAGE SNOWFALL. SINCE SNOWCOVER CAN BE

MAPPED, THERE IS A 33 PERCENT CHANCE OF ANY GIVEN WINTER BEING ABOVE

THE CURRENT NORMAL. BUT WHEN EURASIAN SNOW COVER IS GREATER THAN

NORMAL IN OCTOBER, THE PAST PERCENTAGE HAS INCREASED TO 50 PERCENT.

IF IT WAS BELOW NORMAL, LIKE LAST WINTER, ITS BEEN ONLY 18 PERCENT.

MY COLLEAGUE FROM ACROSS THE AISLE HAS TOLD US THAT FROM A

STATISTICAL POINT, THE EURASIAN OCTOBER SNOW COVER DOES NOT ADD

MUCH CONFIDENCE BEYOND USING WHAT WE HAVE ALREADY BEEN DOING FOR

SEVERAL YEARS: LOOKING AT THE LOCAL OCTOBER AND NOVEMBER

TEMPERATURES. IN A CIRCUITOUS ROUTE (ARRIVING WITH THE SAME

OUTCOME?), THE SNOW COVER INFLUENCES THE PATTERNS WHICH IN TURN

INFLUENCES THE TEMPERATURES. WE HAD A WARM OCTOBER AND FOR THE FIRST

TIME SINCE 1996 WE BELIEVE WILL HAVE A COLD (LOWEST THIRD) NOVEMBER.

THIS TOP THIRD, BOTTOM THIRD COMBO IS NOT COMMON AT ALL IN ANY ENSO

REGIME. SO MUCH SO, FOR OUR ANALOG SERIES TO GET SIX PAST SEASONS,

WE HAD TO INCLUDE A COUPLE OF WEAK EL NINO WINTERS AND ONE ENSO

NEUTRAL NEGATIVE WINTER. ALL HAD WARM OCTOBERS AND COLDER THAN

CURRENT NORMAL NOVEMBERS TO FIT THE TEMPERATURE SEQUENCE. ONLY

1959-60 HAD A LOWEST THIRD (COLD) NOVEMBER. AFTER ALL OF THE

EURASIAN SNOW COVER DISCUSSION IT IS IRONIC THAT ALL OF THESE

ANALOGS OCCURRED PRIOR TO SATELLITE DATA BEING AVAILABLE TO GATHER

THESE STATISTICS. SO HERE ARE OUR CHEAPER BY THE HALF DOZEN ANALOGS

FOR THIS UPCOMING WINTER FOR PHILADELPHIA. THEIR MILEAGE MAY VARY:

SEASON DEC JAN FEB WINTER SEASONAL WINTER

AVG AVG AVG AVG SNOWFALL* PCPN

1914-5 33.3 36.6 38.8 36.2 32.3 19.64

1919-0 32.5 26.8 31.4 30.2 23.2 9.71

1932-3 40.4 42.6 36.7 39.9 22.0 8.98

1941-2 38.3 30.5 30.8 33.2 10.3 9.24

1953-4* 39.4 31.7 41.2 37.4 22.6* 7.58

1959-0 38.2 34.2 35.4 35.9 21.8 10.17

AVG 37.0 33.7 35.7 35.5 22.0 10.89

1981-2010 NML 37.5 33.0 35.7 35.4 22.4 9.24

* THIS INCLUDES THE NOVEMBER SNOW THAT SEASON. THE OFFICIAL CPC OUTLOOK FOR THE WINTER IS FOR EQUAL CHANCES OF IT IT BEING EITHER WARMER OR COLDER THAN NORMAL AND EITHER WETTER OR DRIER THAN NORMAL. WE WANT TO WISH EVERYONE A VERY HAPPY AND HEALTHY WINTER SEASON AND PLEASE USE YOUR SNOW THROWERS AS MUCH OR AS LITTLE AS YOU DESIRE.

those are not a bad set of analogs for NYC...four of the six had a snowstorm with 10" or more...1914-15 was a wet winter with average snowfall due to a 10" April snowfall...1919-20 was very cold and icy/snowy...1932-33 had a good December and February snowfall...That's about it...1941-42 had a mild December but cold January February...It was on the dry side with well below average snowfall...1953-54 had one good early November snowfall and good January...The other months were benign...1959-60 was on the mild side until March...had a White Christmas and March blizzard...Benign between that...

season.....temp...min...snow...big snow...

1914-15...34.0.....3.......28.8".......10.2" April

1919-20...27.4....-2.......47.6".......17.5" Feb.

1932-33...37.8...11.......27.0".......10.0" Feb.

1941-42...32.9.....5.......11.3".........3.2" Jan.

1953-54...37.4.....7.......15.8".........7.8" Jan.

1959-60...36.2.....9.......39.2".......14.5" March

long term-

average...33.4.....4.......28.4"................................

I remember 59-60 well...I was in the fifth grade...NYC had a snowstorm on Dec., 21-22nd...Accumulations ranged from 3" in Philly to 13.7" in Central Park...The rest of the city got 6-8"...Central Park was the bullseye...We had a snow to rain event in January and February...The blizzard on March 3rd-4th was the greatest March storm of my lifetime...

[Rainshadow]

Here is the link to Mark's preliminary numbers:

http://www.erh.noaa.gov/phi/reports/WinterCond2012.pdf