Unusual Soil and Tree Moisture in New England
UPDATE: Maps corrected, my apologies, New England was cut off.
We are releasing a news story today on how the unusual amount of moisture in the trees and soil in New England could lead to an unusual number of uprooted trees should a tropical system threaten the U.S. next week (a different article that we put out today said "a tropical disturbance in one form or another could reach the Bahamas toward the end of next week then pose a threat to the East Coast.") I wanted to present all of the different information here, hat I gleaned from the NOAA Drought & Soil Moisture sites:
Probably the most convincing evidence was that (most of) New England, as of July, is in ranked higher than 95% of recorded values for soil moisture when compared with the 30-year normal (as I understand it from the small amount of documentation provided on their site):
When you instead of one month, that number drops to 90%, but still impressive. As for actual amounts of excess moisture in these time periods, they look like 80-120 mm (3-5 inches) and 60-100 mm (2-4 inches) respectively. Note that, if you look at their animation of the last 10 years, you'll see similar excesses in July 2000 and 2006 (and a couple more other times of year, but we're concentrating on tropical season here).
The long-term Palmer Drought index files (most of) New England under "Extremely Moist" -- the highest category of rain excess.
But the Crop Moisture index, a short-term version of their drought index, shows (most of) New England in an "Abnormally Moist" (but by no means extreme) category.
One thing we didn't state in the article (because we can't measure it) is that tree branches may be heavier than usual (more water in the trees and leaves on them) so combined with excess soil moisture that will not hold roots in well, trees will not do well should a windy low pressure system, of whatever variety, visit New England this month.
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