N. America/N. Hemisphere Snowcover (Jan-July 2000 vs. 2004)
Posted: Fri Aug 20, 2004 2:12 pm
The issue of Northern Hemisphere snowcover arose at another message board. FWIW, when both North American and Northern Hemisphere snowcover for the entire January through July period is considered, 2004 is most similar to 2000:
Snowcover in Millions of Square Km.
Northern Hemisphere:
Month.......2000........2004.......Difference:
Jan...........46.4.........46.1.........0.3
Feb...........43.8.........43.5.........0.3
Mar...........38.0.........37.4.........0.6
Apr...........27.7.........28.4.........0.7
May..........18.6.........18.8.........0.2
Jun.............9.1...........9.4.........0.3
Jul..............3.0...........3.1.........0.1
North America:
Month.......2000........2004........Difference
Jan...........16.5.........17.2.........0.7
Feb...........15.9.........16.9.........1.0
Mar...........13.8.........14.8.........1.0
Apr...........11.8.........11.9.........0.1
May............9.3...........9.2.........0.1
Jun.............5.8...........5.7.........0.1
Jul..............2.4...........2.7.........0.3
However, before one makes the leap that 2000 might be a possible analog (in spite of its many similarities, including U.S. temperature and precipitation anomalies for June-July), there is an important difference:
Summer 2000 neutral ENSO conditions (following a La Niña) and a new La Niña set in for the winter. Summer 2004 has experienced neutral conditions that are trending toward an El Niño for the winter.
Snowcover in Millions of Square Km.
Northern Hemisphere:
Month.......2000........2004.......Difference:
Jan...........46.4.........46.1.........0.3
Feb...........43.8.........43.5.........0.3
Mar...........38.0.........37.4.........0.6
Apr...........27.7.........28.4.........0.7
May..........18.6.........18.8.........0.2
Jun.............9.1...........9.4.........0.3
Jul..............3.0...........3.1.........0.1
North America:
Month.......2000........2004........Difference
Jan...........16.5.........17.2.........0.7
Feb...........15.9.........16.9.........1.0
Mar...........13.8.........14.8.........1.0
Apr...........11.8.........11.9.........0.1
May............9.3...........9.2.........0.1
Jun.............5.8...........5.7.........0.1
Jul..............2.4...........2.7.........0.3
However, before one makes the leap that 2000 might be a possible analog (in spite of its many similarities, including U.S. temperature and precipitation anomalies for June-July), there is an important difference:
Summer 2000 neutral ENSO conditions (following a La Niña) and a new La Niña set in for the winter. Summer 2004 has experienced neutral conditions that are trending toward an El Niño for the winter.