Issued at 1500 UTC SUN SEP 25 2022

000
WTNT23 KNHC 251433
TCMAT3
 
TROPICAL STORM GASTON FORECAST/ADVISORY NUMBER  21
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082022
1500 UTC SUN SEP 25 2022
 
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.
 
TROPICAL STORM CENTER LOCATED NEAR 39.4N  36.5W AT 25/1500Z
POSITION ACCURATE WITHIN  20 NM
 
PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT  10 KT
 
ESTIMATED MINIMUM CENTRAL PRESSURE  997 MB
MAX SUSTAINED WINDS  45 KT WITH GUSTS TO  55 KT.
34 KT.......100NE   0SE  60SW  60NW.
12 FT SEAS..240NE  90SE 120SW 240NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
 
REPEAT...CENTER LOCATED NEAR 39.4N  36.5W AT 25/1500Z
AT 25/1200Z CENTER WAS LOCATED NEAR 39.3N  35.8W
 
FORECAST VALID 26/0000Z 39.2N  38.0W
MAX WIND  40 KT...GUSTS  50 KT.
34 KT... 60NE   0SE  30SW  50NW.
 
FORECAST VALID 26/1200Z 38.7N  39.9W...POST-TROPICAL
MAX WIND  35 KT...GUSTS  45 KT.
34 KT... 50NE   0SE   0SW  50NW.
 
FORECAST VALID 27/0000Z 38.0N  41.8W...POST-TROP/REMNT LOW
MAX WIND  30 KT...GUSTS  40 KT.
 
FORECAST VALID 27/1200Z 37.4N  44.5W...POST-TROP/REMNT LOW
MAX WIND  30 KT...GUSTS  40 KT.
 
FORECAST VALID 28/0000Z 36.8N  47.5W...POST-TROP/REMNT LOW
MAX WIND  25 KT...GUSTS  35 KT.
 
FORECAST VALID 28/1200Z...DISSIPATED
 
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 39.4N  36.5W
 
NEXT ADVISORY AT 25/2100Z
 
$$
FORECASTER PAPIN
 
 

Issued at 300 PM GMT Sun Sep 25 2022

000
WTNT43 KNHC 251436
TCDAT3
 
Tropical Storm Gaston Discussion Number  21
NWS National Hurricane Center Miami FL       AL082022
300 PM GMT Sun Sep 25 2022
 
The large convective burst that fired overnight and this morning
appears to have lead to Gaston's center reforming under the deep
convection further to the north and west. This also evident in
GOES-16 GLM lightning data that showed a clear arcing pattern
embedded in the convection prior to the new center becoming evident
on visible satellite imagery.  Since then, the convection has been
rapidly decaying, as the storm loses instability support from a
sharp upper-level trough as it moves into its axis. Subjective and
objective Dvorak numbers this morning were still CI 3.0/45-kt from
TAFB and UW-CIMSS ADT. While scatterometer data largely missed the
circulation earlier, it still showed tropical storm force winds
extending well to the northeast of the center. The initial intensity
is being maintained at 45 kt for this advisory.
 
Gaston, post reformation, has made its westward turn, with the
latest motion estimate at 270/10 kt. Gaston is currently situated
between an anomalously strong deep-layer ridge to its northeast, and
a more climatological ridge to its southwest. These features are
forecast to merge over the next 24-48 hours to the northwest of
Gaston, and should help steer the storm more to the west-southwest
for the remainder of its lifespan. The guidance this cycle is just a
bit further south and west compared to the previous cycle, and the
latest NHC track forecast was nudged in that direction, following
the consensus aids TVCN and HCCA.
 
Gaston might have had its last convective hurrah this morning, with 
the GFS, ECMWF, CMC, and HWRF suggesting the storm will struggle to 
produce organized convection from here on out. This could be related 
to the upper-level flow pattern, where the storm is moving out of an 
environment favorable for ascent into an environment favorable for 
descent, limiting convection, especially as it continues to traverse 
24-25C SSTs. The latest forecast still shows Gaston becoming a 
post-tropical cyclone in about 24 hours, but if the convection does 
not return before then, this evolution could occur sooner. The low 
should persist another day or two before it opens up into a trough 
in the subtropical Atlantic in about 72 hours, in agreement with the 
majority of the global model guidance.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/1500Z 39.4N  36.5W   45 KT  50 MPH
 12H  26/0000Z 39.2N  38.0W   40 KT  45 MPH
 24H  26/1200Z 38.7N  39.9W   35 KT  40 MPH...POST-TROPICAL
 36H  27/0000Z 38.0N  41.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
 48H  27/1200Z 37.4N  44.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  28/0000Z 36.8N  47.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  28/1200Z...DISSIPATED
 
$$
Forecaster Papin
 

…GASTON MOVING WESTWARD WITH NO CHANGE IN STRENGTH…
As of 3:00 PM GMT Sun Sep 25
the center of Gaston was located near 39.4, -36.5
with movement W at 12 mph.
The minimum central pressure was 997 mb
with maximum sustained winds of about 50 mph.

Issued at 300 PM GMT Sun Sep 25 2022

000
WTNT33 KNHC 251434
TCPAT3
 
BULLETIN
Tropical Storm Gaston Advisory Number  21
NWS National Hurricane Center Miami FL       AL082022
300 PM GMT Sun Sep 25 2022
 
...GASTON MOVING WESTWARD WITH NO CHANGE IN STRENGTH...
 
 
SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...39.4N 36.5W
ABOUT 420 MI...680 KM W OF FAIAL ISLAND IN THE CENTRAL AZORES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES
 
 
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
 
 
DISCUSSION AND OUTLOOK
----------------------
At 300 PM GMT (1500 UTC), the center of Tropical Storm Gaston was
located near latitude 39.4 North, longitude 36.5 West. Gaston is
moving toward the west near 12 mph (19 km/h). A gradual turn toward
the west-southwest is forecast by tomorrow.
 
Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Gradual weakening is forecast over the next few days, and Gaston is
forecast to become a post-tropical cyclone by Monday.
 
Tropical-storm-force winds extend outward up to 115 miles (185 km)
from the center.
 
The estimated minimum central pressure is 997 mb (29.44 inches).
 
 
HAZARDS AFFECTING LAND
----------------------
SURF:  Swells generated by Gaston are expected to affect portions of
the Azores today.  These swells are likely to cause life-threatening
surf and rip current conditions.
 
 
NEXT ADVISORY
-------------
Next complete advisory at 900 PM GMT.
 
$$
Forecaster Papin
 

…CENTER OF GASTON REFORMS FURTHER WEST… …TROPICAL STORM WARNINGS FOR THE AZORES HAVE BEEN DISCONTINUED…
As of 12:00 PM GMT Sun Sep 25
the center of Gaston was located near 39.3, -35.8
with movement W at 10 mph.
The minimum central pressure was 997 mb
with maximum sustained winds of about 50 mph.

Issued at 1200 PM GMT Sun Sep 25 2022

000
WTNT33 KNHC 251148
TCPAT3
 
BULLETIN
Tropical Storm Gaston Intermediate Advisory Number 20A
NWS National Hurricane Center Miami FL       AL082022
1200 PM GMT Sun Sep 25 2022
 
...CENTER OF GASTON REFORMS FURTHER WEST...
...TROPICAL STORM WARNINGS FOR THE AZORES HAVE BEEN DISCONTINUED...
 
 
SUMMARY OF 1200 PM GMT...1200 UTC...INFORMATION
-----------------------------------------------
LOCATION...39.3N 35.8W
ABOUT 380 MI...610 KM W OF FAIAL ISLAND IN THE CENTRAL AZORES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
 
The Azores Meteorological Service has discontinued the Tropical 
Storm Warning for the islands of Flores and Corvo in the western 
Azores. 
For additional storm information specific to your area, please 
monitor products issued by your national meteorological service. 
 
SUMMARY OF WATCHES AND WARNING IN EFFECT:
 
There are no coastal watches or warnings in effect. 
 
 
DISCUSSION AND OUTLOOK
----------------------
At 1200 PM GMT (1200 UTC), the center of Tropical Storm Gaston has 
reformed near latitude 39.3 North, longitude 35.8 West. Gaston is 
now moving toward the west near 10 mph (17 km/h).  A gradual turn to 
the west-southwest is forecast by Monday.
 
Maximum sustained winds are near 50 mph (85 km/h) with higher
gusts. Gradual weakening is forecast over the next few days, and
Gaston is expected to become a post-tropical cyclone tonight or on
Monday.
 
Tropical-storm-force winds extend outward up to 115 miles (185 km)
from the center.
 
The estimated minimum central pressure is 997 mb (29.44 inches).
 
 
HAZARDS AFFECTING LAND
----------------------
Key messages for Gaston can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC
and on the web at hurricanes.gov/text/MIATCDAT3.shtml.
 
SURF:  Swells generated by Gaston are expected to affect portions of
the Azores today.  These swells are likely to cause life-threatening
surf and rip current conditions.
 
RAINFALL:  Gaston is expected to produce additional rainfall 
accumulations of 1 to 2 inches across the western Azores today. This 
will result in storm total rainfall maxima up to 6 inches which may 
result in landslides and areas of flooding.
 
 
NEXT ADVISORY
-------------
Next complete advisory at 300 PM GMT.
 
$$
Forecaster Papin
 

…GASTON MOVING WEST-NORTHWESTWARD AWAY FROM THE AZORES…
As of 9:00 AM GMT Sun Sep 25
the center of Gaston was located near 39.0, -34.5
with movement WNW at 10 mph.
The minimum central pressure was 997 mb
with maximum sustained winds of about 50 mph.

Issued at 900 AM GMT Sun Sep 25 2022

000
WTNT33 KNHC 250840
TCPAT3
 
BULLETIN
Tropical Storm Gaston Advisory Number  20
NWS National Hurricane Center Miami FL       AL082022
900 AM GMT Sun Sep 25 2022
 
...GASTON MOVING WEST-NORTHWESTWARD AWAY FROM THE AZORES...
 
 
SUMMARY OF 900 AM GMT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...39.0N 34.5W
ABOUT 315 MI...505 KM W OF FAIAL ISLAND IN THE CENTRAL AZORES
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
 
None.
 
SUMMARY OF WATCHES AND WARNING IN EFFECT:
 
A Tropical Storm Warning is in effect for...
* Flores and Corvo in the western Azores
 
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
 
For storm information specific to your area, please monitor
products issued by your national meteorological service.
 
 
DISCUSSION AND OUTLOOK
----------------------
At 900 AM GMT (0900 UTC), the center of Tropical Storm Gaston was
located near latitude 39.0 North, longitude 34.5 West. Gaston is
moving toward the west-northwest near 10 mph (17 km/h).  A turn 
toward the west is expected later today, and a turn to the
west-southwest is forecast by Monday.
 
Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Gradual weakening is forecast over the next few days, and Gaston is 
expected to become a post-tropical cyclone tonight or on Monday.
 
Tropical-storm-force winds extend outward up to 115 miles (185 km)
from the center.
 
The estimated minimum central pressure is 997 mb (29.44 inches).
 
 
HAZARDS AFFECTING LAND
----------------------
Key messages for Gaston can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC
and on the web at hurricanes.gov/text/MIATCDAT3.shtml.
 
WIND:  Tropical-storm-force winds are expected in portions of the
western Azores for a few more hours.  See products issued by the
meteorological service in the Azores for more information.
 
SURF:  Swells generated by Gaston are expected to affect portions of
the Azores today.  These swells are likely to cause life-threatening
surf and rip current conditions.
 
RAINFALL:  Gaston is expected to produce additional rainfall
accumulations of 1 to 2 inches across the western Azores this
morning. This will result in storm total rainfall maxima up to 6
inches which may result in landslides and areas of flooding.
 
 
NEXT ADVISORY
-------------
Next intermediate advisory at 1200 PM GMT.
Next complete advisory at 300 PM GMT.
 
$$
Forecaster Beven
 

…GASTON STILL MOVING GENERALLY WESTWARD… …TROPICAL STORM CONDITIONS EXPECTED TO CONTINUE ACROSS THE WESTERN AZORES FOR A FEW MORE HOURS…
As of 6:00 AM GMT Sun Sep 25
the center of Gaston was located near 38.8, -33.9
with movement W at 12 mph.
The minimum central pressure was 997 mb
with maximum sustained winds of about 50 mph.