[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT41 KNHC 050245
TCDAT1

Tropical Storm Earl Discussion Number   9
NWS National Hurricane Center Miami FL       AL062022
1100 PM AST Sun Sep 04 2022

Earl continues to produce intense deep convection with tops colder
than -80 deg C over the eastern portion of its circulation,
but the system still lacks clear-cut banding features.  A 2306 UTC
SSMIS microwave image showed that the low-level center is displaced
to the west-southwest of the main area of convection.  Dvorak
intensity estimates range from 45 kt to 55 kt, and given that there
has been no obvious change in organization since the aircraft
missions earlier today, the current intensity estimate is held at 45
kt for this advisory.

The storm is still being affected by southwesterly vertical wind
shear associated with an upper-level trough located several hundred
miles to the west and northwest.  However, Earl's upper-level
outflow pattern is gradually becoming better defined, and global
model predictions suggest a slow relaxation of the shear over the
next several days as the trough shifts a little to the northwest.
Since the other environmental factors appear conducive for
strengthening, gradual intensification is likely.  The official
intensity forecast is close to both the simple and corrected model
consensus and also very similar to the previous NHC forecast.  Earl
could become the first major hurricane of this Atlantic season.

Earl's motion is a somewhat uncertain but slow 305/3 kt.  The storm
remains in a region of weak steering currents with mid-level
anticyclones currently located to the west, northwest and east.  By
tomorrow, however, Earl should begin to move northward into a
weakness in the subtropical ridge.  Later in the forecast period,
the cyclone is expected to start coming under the influence of a
trough in the southern portion of the mid-latitude westerlies and
turn toward the north-northeast and northeast.  The official track
forecast is just slightly left of the previous NHC track and close
to the latest dynamical model consensus.  This is roughly in the
middle of the rather tightly clustered track guidance model suite.

While tropical-storm-force winds are still forecast to stay north of
the northern Leeward Islands, the Virgin Islands, and Puerto Rico,
training rainbands are producing heavy rainfall over portions of
these islands.  Users should refer to products issued by local
weather offices in these areas.

KEY MESSAGES:

1.  Heavy rainfall from Earl is expected to lead to limited flash,
urban, and small stream flooding impacts over the Leeward Islands,
U.S. and British Virgin Islands, and Puerto Rico today. Rapid rises
on rivers and mudslides in areas of steep terrain are possible in
Puerto Rico.  Considerable flood impacts cannot be ruled out in
areas that receive heavier rainfall totals.

2.  Earl is forecast to remain to the north of the the Virgin
Islands and Puerto Rico tonight, but gusty winds, especially in
squalls, remain possible on those islands overnight.


FORECAST POSITIONS AND MAX WINDS

INIT  05/0300Z 20.2N  65.4W   45 KT  50 MPH
 12H  05/1200Z 21.3N  65.6W   50 KT  60 MPH
 24H  06/0000Z 22.5N  65.7W   55 KT  65 MPH
 36H  06/1200Z 23.6N  65.8W   60 KT  70 MPH
 48H  07/0000Z 24.5N  65.9W   65 KT  75 MPH
 60H  07/1200Z 25.4N  65.8W   70 KT  80 MPH
 72H  08/0000Z 26.4N  65.5W   75 KT  85 MPH
 96H  09/0000Z 28.7N  64.4W   90 KT 105 MPH
120H  10/0000Z 32.0N  61.5W  105 KT 120 MPH

$$
Forecaster Pasch
This weather bulletin was brought to you by:
www.nashvilleweather.net