Monday, June 14, 2021

TD 2 Becomes Tropical Storm Bill


























842 
WTNT32 KNHC 150237
TCPAT2

BULLETIN
Tropical Storm Bill Advisory Number   3
NWS National Hurricane Center Miami FL       AL022021
1100 PM AST Mon Jun 14 2021

...DEPRESSION STRENGTHENS INTO TROPICAL STORM BILL...
...LIKELY TO BE SHORT-LIVED...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...36.7N 69.8W
ABOUT 335 MI...540 KM ENE OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...NE OR 55 DEGREES AT 23 MPH...37 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Storm Bill was
located near latitude 36.7 North, longitude 69.8 West. Bill is
moving toward the northeast near 23 mph (37 km/h), and this general 
motion is expected through Wednesday with increasing forward speed.

Satellite-derived wind data indicate that the maximum sustained 
winds have increased to near 45 mph (75 km/h) with higher gusts. 
Some additional strengthening is possible on Tuesday, however the 
system is expected to become a post-tropical low and dissipate on 
Wednesday.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
from the center.

The estimated minimum central pressure is 1003 mb (29.62 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Pasch

000
WTNT42 KNHC 150238
TCDAT2

Tropical Storm Bill Discussion Number   3
NWS National Hurricane Center Miami FL       AL022021
1100 PM AST Mon Jun 14 2021

Deep convection has increased in a cluster to the northeast of the 
estimated center.  Scatterometer measurements showed a couple of 
40-41 kt vectors over the southeastern quadrant of the cyclone.  On 
this basis, the estimated intensity is increased to 40 kt, which 
makes this the second tropical storm of the season, albeit a rather 
high-latitude one.  The system is in an environment of fairly 
strong southwesterly shear, but the diffluent upper-level flow has 
apparently contributed to some strengthening in a seemingly hostile 
environment.  Some additional short-term strengthening could occur 
but by 36 hours, the cyclone should merge with a baroclinic zone 
while approaching Newfoundland and become extratropical.  This 
transition is also shown by the FSU cyclone phase analyses of the 
GFS model fields.

Bill is moving fairly swiftly northeastward, or 055/20 kt.  The 
track forecast appears to be straightforward.  The flow ahead of a 
large mid-tropospheric trough near the United States east coast 
should accelerate the system northeastward for the next day or two, 
and until the system dissipates.  The NHC track forecast is similar 
to the previous one and not far from the model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  15/0300Z 36.7N  69.8W   40 KT  45 MPH
 12H  15/1200Z 38.9N  65.1W   45 KT  50 MPH
 24H  16/0000Z 42.6N  59.6W   40 KT  45 MPH
 36H  16/1200Z 46.5N  54.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
 48H  17/0000Z...DISSIPATED

$$
Forecaster Pasch

Surprise Tropical Depression Two Forms East Of Cape Hatteras, North Carolina


























000
WTNT32 KNHC 141438
TCPAT2

BULLETIN
Tropical Depression Two Advisory Number   1
NWS National Hurricane Center Miami FL       AL022021
1100 AM EDT Mon Jun 14 2021

...TROPICAL DEPRESSION FORMS OFFSHORE OF NORTH CAROLINA...
...HEADING AWAY FROM THE UNITED STATES...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...35.0N 73.7W
ABOUT 105 MI...165 KM E OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NE OR 50 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 1100 AM EDT (1500 UTC), the center of Tropical Depression Two was
located near latitude 35.0 North, longitude 73.7 West. The
depression is moving toward the northeast near 21 mph (33 km/h), and
this general motion is expected through Wednesday with increasing 
forward speed.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
The depression is expected to become a tropical storm by tonight 
and could continue to strengthen on Tuesday.  The system should 
begin to weaken by Tuesday night and is expected to dissipate on 
Wednesday.

The estimated minimum central pressure is 1006 mb (29.71 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 500 PM EDT.

$$
Forecaster Blake

000
WTNT42 KNHC 141442
TCDAT2

Tropical Depression Two Discussion Number   1
NWS National Hurricane Center Miami FL       AL022021
1100 AM EDT Mon Jun 14 2021

Satellite and radar images show that the low pressure area that NHC 
has been following since yesterday off the coast of North Carolina 
has become better organized, with a small central dense overcast 
over the center and more prominent banding features.  The low also 
has advanced ahead of a nearby diffuse stationary front, with that 
boundary lying northwest of the center.  Considering the small core 
of the low, ample deep convection, satellite pattern, and that the 
low is feeding off of the thunderstorm activity (and not the front) 
-- it is now classified as a tropical depression.  The initial 
intensity is set to 30 kt, which is our best estimate assuming 
strengthening from the 20-25 kt overnight ASCAT and surface 
observations.

The depression is moving northeastward at about 18 kt.  A large 
mid-latitude trough digging across eastern North America should 
cause the cyclone to continue moving generally northeastward, but 
faster, over the next couple of days.  In about 48 hours, the system 
is forecast to dissipate near Newfoundland as it is absorbed by a 
larger extratropical low.  Model guidance is in very good agreement 
on this scenario, and the NHC forecast lies near the track 
consensus.

The depression has about 24 hours over marginally warm waters in
low-to-moderate shear to strengthen before it moves north of the 
Gulf Stream and decays.  Almost all of the intensity guidance shows 
the system becoming a tropical storm tonight, and considering the
healthy initial structure, the official forecast follows that
guidance.  The low should lose tropical characteristics in about 36
hours due to very cold waters and dissipate near Newfoundland in 
about 2 days.  

FORECAST POSITIONS AND MAX WINDS

INIT  14/1500Z 35.0N  73.7W   30 KT  35 MPH
 12H  15/0000Z 36.6N  70.9W   40 KT  45 MPH
 24H  15/1200Z 39.8N  65.3W   45 KT  50 MPH
 36H  16/0000Z 43.6N  59.7W   40 KT  45 MPH...POST-TROP/EXTRATROP
 48H  16/1200Z...DISSIPATED

$$
Forecaster Blake