365 Days of Climate Awareness 143 – 2005 State of the Climate, North America and Europe

2005 US Climate Data

• Global atmospheric CO₂ concentration: 378.98 ppm, +2.03 ppm from 2004
• Average air temperature: 55.5°F, 11^th all-time 1895-2021
• Average precipitation: 27.79”, 67^th wettest 1895-2021
• Tornadoes: 1262, 34 (2.8%) above the 1991-2010 average 1228
• 27 named tropical cyclones: 15 became hurricanes, 5 major (winds > 111 mph, 3-5 Saffir-Simpson)
• ENSO: Neutral, with signs of incipient La Niña by year’s end

North American Conditions

• Warmer than average: Almost all of US (especially Colorado, Wyoming & Utah); Canada (BC & Yukon warmest ever); Mexico; Europe
• Drought: Northwestern US
• Above-average precipitation: New England; southwestern US; Yukon; Saskatchewan; Manitoba; parts of BC & Alberta; Mexico; southeastern Europe
• Wildfires: Texas, Oklahoma & southern plains (winter): then-record year for US acreage burnt

Snowpack was below average for most of North America, continuing a trend which has largely held (excepting four years) since the late 1980’s. Hurricane Katrina struck New Orleans and the central Gulf Coast, leading to the horrors which to this day have been only partly rectified. Combined with Hurricane Rita later in the same year, there was over $125B in damage and 1000 deaths. The season also included Hurricane Wilma, the most intense ever recorded, which impacted Mexico. They were the three most intense North American hurricanes of the year, and rank 15-16-17 historically.

The year’s ACE (Accumulated Cyclone Energy) was 270.21 (a unitless index calculated from squares of cyclone wind speeds: see post 139), the highest on record. Roughly halfway through the cynically misnamed global warming “pause” (which includes several years of top-10 historical average air temperatures), the warming oceans combined with a neutral ENSO to produce a catastrophic outbreak of cyclone energy in the Atlantic. Globally sea surface temperatures were warmer than average and the Ocean Heat Content Anomaly—a measure of the heat stored in the upper 750 m of the ocean—showed a larger anomaly—with the ocean containing an unusually large amount of heat--in the subpolar region of the North Atlantic, and a smaller anomaly in the (already warm) subtropical region.

2005 US Percentage Area Very Dry vs Very Wet

2005 US Percentage Area Very Warm vs Very Cold

North Atlantic Hurricane Counts and ACE Index, 1950-2020.

Tomorrow: 2005 State of the World Climate.

Be brave, and be well.