BIRDSEYE VIEW POSTS

Since 2012 on the now retired Weather Underground blogs, I have been posting annotated "birdseye view" charts of the Atlantic basin, with a detailed explanation and forecasting that references the chart. From there you may know me as "NCHurricane2009." While I now do these "birdseye view" posts here, I will continue to do comments at Yale Climate Connections via Disqus where the former Weather Underground community has moved to. Feel free to reply to me there, at my Disqus feed at this link, or via e-mail at IOHurricanes@outlook.com 

 
 
Search
  • NCHurricane2009

MY 2022 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #109A (Special Update)

*******Note that forecast 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 SEPTEMBER 23 2022 2:08 PM EDT...

Infrared satellite image of the northwestern Atlantic taken at 1510Z (11:10 AM EDT) at the time Fiona regained category 4 hurricane strength at an unusually far north location:

The following is a special update on recent events with Major Hurricane Fiona. See full update #109 for more information on Fiona... Tropical Storm Gaston moving slowly southeastward into the Azores... Tropical Depression Nine in the Caribbean Sea... and other areas of interest being monitored for development across the Atlantic tropics (note that area of interest #32 mentioned in full update #109... located between the Republic of Cabo Verde Islands and west coast of Africa... has also been recently upgraded by the NHC to Tropical Depression Ten).


The east side of Fiona delivered strong winds... heavy rains... and coastal surf to Bermuda early today. Observations (weather.bm/observations.asp) show that winds peaked at 6:56 local time with a sustained measurement of 61 mph with a gust of 93 mph. Although sustained winds climbed to 64 mph at 8:16 local time... the gust was a little lower while clocked in at 83 mph. Sustained winds dropped below storm force (below 40 mph) since 12:55 local time as weather conditions improve with Fiona pulling rapidly north-northeastward and away.


As of 11 AM EDT... Fiona incredibly regained category 4 maximum sustained winds of 130 mph while at an unusually far north location north of Bermuda. The central surface pressure of the hurricane has remained steady at a dangerously low mid-930s of mb... so the recent increase in wind is probably attributed to the north-northeastward forward speed of the storm increasing which is helping to accelerate the wind on the east side of the eye instead of being caused by a drop in pressure. The fact that Fiona is maintaining such a low surface pressure despite moving over increasingly cooler water is a glaring warning sign that Fiona is having tremendous upper air support thanks to strong upper southerly flow on the east side of the incoming Canadian upper trough which is helping to enhance Fiona's northern outflow. Tremendous upper air support will continue as Fiona moves toward and then into Atlantic Canada while the hurricane enters the tremendous eastern divergence zone of the upper trough. The strong hurricane's west side will also pull the trough's cold air southward... helping to further amplify the upper trough and re-enforce the tremendous eastern divergence zone of the trough which will in turn only re-enforce Fiona's surface low pressure and strength. The storm's size will also grow due to the expansiveness of the trough's upper divergence zone. When all is said and done... Atlantic Canada will likely be struck by one of the strongest cyclones ever recorded in the region... featuring one of the lowest surface central pressures ever recorded in the region.


Regarding impact to land areas going forward:

(1) Fiona will bring coastal swells and rip currents to the United States mid-Atlantic and northeast coastline through this weekend. The west side of the large and intense remnant frontal cyclone of Fiona could also bring gusty winds to Maine this weekend.

(2) For Bermuda... coastal surf being generated by the hurricane will decrease as Fiona continues pulling away from the area.

(4) Fiona's large and intense remnant frontal cyclone will bring damaging hurricane force winds are expected across eastern Nova Scotia... Prince Edward Island... western Newfoundland... and eastern Quebec. Gale force winds with some damage potential are expected across New Brunswick... western Nova Scotia... eastern Newfoundland... and Labrador. Across all of these areas... expect rather dangerous coastal surf with storm surges due to the forecast large size and strength of Fiona's remnant cyclone. Heavy rainfall with flash flooding potential is another hazard to consider. I recommend preparations in the region should be rushed to completion by tonight.

9 views0 comments