scott's 2012-2013 winter forecast ! how do i make a forecast?

Scott's 2012-2013 Winter Forecast !

How do I make a forecast?

El Nino or La Nina? -2011

Warmer than normal water

Cooler than normal water

Typical La Nina Pattern

El Nino or La Nina? -2012

Warmer than normal water

Cooler than normal water

Typical El Nino Pattern

El Nino or La Nina? -2012

So what are we in?

Looks like a Weak El Nino/Neutral

(Also known as “La Nada”)

What is the PDO? Pacific Decadal Oscillation An index derived from Northern Pacific sea

surface temperature anomalies. Negative PDO brings a trough into western

North America and a ridge across eastern North America

Helps determine El Nino/La Nina(-PDO: El Nino weaker, La Nina stronger; +PDO: El Nino stronger and longer lasting, La Nina weaker)

Pacific Decadal Oscillation-2011

A -PDO helps strengthen La Nina

Pacific Decadal Oscillation-2012

Always look at snow and ice cover ! (2011)

Always look at snow and ice cover ! (2012)

Early December 2012 snow & ice cover

North Atlantic Oscillation(“The Wildcard”)

North Atlantic Oscillation(“The Wildcard”)

Arctic Oscillation (AO)

Courtesy: Hazardous Weather Prediction Center (http://www.hwpcwx.org/)

Analog Years

1989-1990 (Neutral) 1992-1993 (Neutral) 1993-1994 (Neutral) 1998-1999 (Moderate La Nina) 2003-2004 (Neutral) 2008-2009 (Neutral) 2011-2012 (Weak La Nina)

About the analog years

1989-1990: 1992-1993: “Storm of the Century”-occurred in

neutral year 1993-1994: Ice storms in neutral year 1998-1999: Record highs in December 2003-2004: 2008-2009: Early season snow, big snowstorm in

March 2011-2012: Early season snow

Central Park Snowfall (analog years vs. average)

SEASON JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN TOTAL

• 1989-90 0 0 0 0 4.7 1.4 1.8 1.8 3.1 0.6 0 0 13.4

• 1992-93 0 0 0 0 0 0.4 1.5 10.7 11.9 0 0 0 24.5

• 1993-94 0 0 0 0 T 6.9 12.0 26.4 8.1 0 0 0 53.4

• 1998-99 0 0 0 0 0 2.0 4.5 1.7 4.5 0 0 0 12.7

• 2003-04 0 0 0 0 0 19.8 17.3 0.7 4.8 0 0 0 42.6

• 2008-09 0 0 0 0 T 6.0 9.0 4.3 8.3 T 0 0 27.6

• 2011-12 0 0 0 2.9 0 0 4.3 0.2 0 0 0 0 7.4

AVERAGE 0.0 0.0 0.0 T 0.3 4.8 7.0 8.8 3.6 0.6 0.0 0.0 25.1 (1981-2010)

Philly Snowfall(analog years vs average)

SEASON JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN TOTAL

AVERAGE 0.0 0.0 0.0 0.0 0.3 3.6 7.1 8.7 2.5 0.5 0.0 0.0 22.8

(1981-2010)

17“ 24.3”23.1”12.5 “

2011-2012 total: 2.4”

16.3“ 10.1“

Atlantic City Snowfall(analog years vs average)

SEASON JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN TOTAL

AVERAGE 0.0 0.0 0.0 0.0 0.2 3.6 4.7 6.8 1.1 0.3 0.0 0.0 16.8

(1981-2010)

Temperature anomalies- December

Temperature anomalies- January

Temperature anomalies- February

Precipitation anomalies- December

Precipitation anomalies- January

Precipitation anomalies- February

What do the maps mean then?

• Temperatures for Central Park(1981-2010 avg):• Dec Avg: 37.5 F • (My outlook: +0.00 F)• Jan Avg: 32.6 F• (My outlook: -0.00 F)• Feb Avg: 35.3 F• (My outlook: -1.00 F)

What do the maps mean then?

• Liquid Precipitation for Central Park(1981-2010 avg):

• Dec: 4.00” • (Outlook +0.75”)• Jan: 3.65”• (Outlook -0.75”)• Feb: 3.09”• (Outlook -0.75”)

What do the maps mean then?

• Temperatures for Philly Int’l(1981-2010 avg):

• Dec Avg: 37.4 F • (My outlook: 0.00 F)• Jan Avg: 32.9 F• (My outlook: 0.00 F)• Feb Avg: 35.6 F• (My outlook: 0.00 F)

What do the maps mean then?

• Liquid Precipitation for Philly Int’l(1981-2010 avg):

• Dec: 3.55” • (Outlook 0.00”)• Jan: 3.03”• (Outlook +0.75”)• Feb: 2.64”• (Outlook -0.75”)

What do the maps mean then?

• Temperatures for Atlantic City(1981-2010 avg):

• Dec Avg: 37.0 F • (My outlook: -0.50 F)• Jan Avg: 32.8 F• (My outlook: 0.00 F)• Feb Avg: 35.1 F• (My outlook: -0.00 F)

What do the maps mean then?

• Liquid Precipitation for Atlantic City(1981-2010 avg):

• Dec: 3.68” • (Outlook +0.50”)• Jan: 3.28”• (Outlook +0.50”)• Feb: 2.87”• (Outlook -0.75”)

So what are my thoughts about snowfall this Winter?

• At or slightly above average snowfall along I-95 corridor; average along the coast

• The further N&W you go, the snowier it will be (elevation, colder air in place)

• A -NAO can throw a curve ball and with cold air in place there could be at least 1-2 big snowstorms (coastal storms)

•

My prediction (includes November 8th storm)

Want to find out more this Winter?

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