MY 2021 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #45 (Weekend Edition)
*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.**********
...FRIDAY JULY 9 2021 10:47 PM EDT...
Satellite image as of 0040Z. Areas of interest circled in yellow are not mentioned in the NHC tropical weather outlook. Areas circled in a green dashed line are in the NHC 5-day tropical weather outlook. Areas circled in a solid green line are in the NHC 2-day tropical weather outlook:
NHC TAFB Surface Analysis 1800Z:
GFS Model Upper-Level Winds 1800Z:
Note that this is a weekend edition post (no computer model summary and above-style charts created by mobile phone) as I am currently on vacation.
Elsa has completed transition from a tropical storm to a non-tropical frontal cyclone…see remnants of Elsa section below for an update on the remnant cyclone. Elsewhere…the surface low pressure over south Texas supported by the divergence zone of a small area of upper vorticity over the state has as forecast drifted northward and more inland while pushed by the west side of the Atlantic surface ridge. This has made the rainfall associated with this system less widespread while this system has less access to the northwest Gulf of Mexico waters…which will alleviate some flooding concerns in the region…and ensures no tropical cyclone formation will occur here.
REMNANTS OF ELSA...While moving very rapidly northeast under the east side of the large upper trough approaching from eastern North America…Elsa has covered a lot of ground in the last 24 hours while crossing through all of the coastal northeastern US…and is already centered just offshore of Maine while about to make landfall in New Brunswick. The strongest wind (and thus the coastal sea swells) however will skirt over Nova Scotia and Newfoundland while winds on the southeast side of Elsa are enhanced by the fast forward speed of the system…while wind on the northwest side is suppressed by this fast forward speed. Heavy rainfall will include New Brunswick and Prince Edward Island in addition to Nova Scotia and Newfoundland as the track has been a bit more toward the north and west compared to previous forecasts. The former tropical storm has completed transition to a still-vigorous non-tropical frontal cyclone due to cooler water temps and support of the divergence region of the aforementioned upper trough…and due to it’s vigorous nature the remnant cyclone will bring impacts as outlined above.
Here are some of the strongest National weather service (weather.gov) and Environment Canada (weather.gc.ca) station reports of wind (mph) generated by Elsa over the last several hours (Environment Canada value in kph kept in parenthesis):
**Barnstable MA (Cape Cod area)…sustained 21…gust 41 (12:56 PM EDT)
**Boston MA…sustained 18…gust 33 (3:54 PM EDT)
**Worcester MA…sustained 21…gust 30 (3:54 PM EDT)
**Concord NH…sustained 17 (2:51 PM EDT)
**Portsmouth NH…sustained 22…gust 29 (3:56 PM EDT)
**Portland ME…sustained 14…gust 23 (6:51 PM EDT)
**Augusta ME…sustained 18…gust 24 (5:53 PM EDT)
**Fredericton NB…sustained 10 (17)…gust 17 (28) (22:00 local time)
**St John NB…sustained 18 (30)…gust 27 (43) (22:00 local time)
**Halifax NS…sustained 21 (35)…gust 31 (51) (now)
**Charlottetown PE…sustained 11 (18) (now)