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National Climate Assessment: The weather of the Mid-Atlantic’s future

The massive Federal review of climate change trends and projections released today documents a warming Mid-Atlantic that will grow warmer in the coming decades.  Along with soaring temperatures, we can expect more intense downpours, higher seas and stronger hurricanes, the report says.

Related: National Climate Assessment: 15 arresting images of climate change now and in the pipeline | U.S. climate report says global warming impact already severe

How intense these changes become depends on whether human emissions of greenhouse gases slow or continue unabated, the report stresses.

Below, I extract (from the report’s chapter on the Northeast and Southeast U.S.) some of the key projections and images that pertain to the Mid-Atlantic’s future weather:

Hotter temperatures

Key statements:

“…the majority of Maryland and Delaware, and southwestern West Virginia and New Jersey, are projected by mid-century to experience more than 60 additional days per year above 90°F compared to the end of last century under continued increases in emissions”

“The frequency, intensity, and duration of cold air outbreaks is expected to decrease as the century progresses, although some research suggests that loss of Arctic sea ice could indirectly reduce this trend by modifying the jet stream and mid-latitude weather patterns.”

More extreme precipitation

Key statements

“The frequency of heavy downpours is projected to continue to increase as the century progresses…”

“Seasonal drought risk is also projected to increase in summer and fall as higher temperatures lead to greater evaporation and earlier winter and spring snowmelt.”

“Winter and spring precipitation is projected to increase…”

“Projected changes in summer and fall, and for the entire year, are generally small at the end of the century compared to natural variations.”

Higher sea Level

Key statements

“Sea level rise along most of the coastal Northeast is expected to exceed the global average rise due to local land subsidence, with the possibility of even greater regional sea level rise if the Gulf Stream weakens as some models suggest.”

“Sea level rise of two feet, without any changes in storms, would more than triple the frequency of dangerous coastal flooding throughout most of the Northeast.”

“…in the Mid-Atlantic…, estimates suggest that between 450,000 and 2.3 million people are at risk from a three foot sea level rise.”

Shifting winter (cold season) storms

Key statements

“In the mid-latitudes, where most of the continental U.S. is located, there is an increasing trend in extreme precipitation in the vicinity of fronts associated with mid-latitude storms.”

“There is also a northward shift in storms over the U.S. that are often associated with extreme precipitation. This shift is consistent with projections of a warming world. No change in mid-latitude storm intensity or frequency has been detected.”

Severe storms/tornadoes still under investigation

Key statements

“Although these relationships are still being explored, a recent study suggests a projected increase in the frequency of conditions favorable for severe thunderstorms.”

Stronger hurricanes

Key statements

“…there is a growing consensus  based on scientific understanding and very-high-resolution atmospheric modeling that the strongest tropical cyclones including Atlantic hurricanes, will become stronger in a warmer world.”

“By late this century, models, on average, project a slight decrease in the annual number of tropical cyclones … There is some uncertainty in this as the individual models do not always agree…”

” … almost all existing studies project greater rainfall rates in hurricanes in a warmer climate, with projected increases of about 20% averaged near the center of hurricanes.”

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