560
WTNT45 KNHC 101442
TCDAT5

Tropical Storm Jerry Discussion Number 13
NWS National Hurricane Center Miami FL AL102025
1100 AM AST Fri Oct 10 2025

Jerry is not a healthy tropical storm this morning. The low-level
circulation, as seen in satellite imagery and Air Force Reserve
Hurricane Hunter data, is elongated in a southeast-northwest
direction with most of the associated deep convection displaced
well to the south-southeast. The current intensity is held at 45
kt, based on a maximum 850-mb flight-level wind of 54 kt measured
by the reconnaissance aircraft and recent ASCAT data. All of the tropical-storm-force winds appears to be within the eastern
semicircle.

With the center not all that well defined, the current motion
estimate of northwestward (325 degrees) at 14 kt is a bit
uncertain. Jerry is expected to turn northward later today as it
moves around the western periphery of the subtropical ridge, with
that trajectory continuing through early Sunday. Then, a sharp
northeastward and eastward turn is expected by Sunday night and
Monday as Jerry becomes embedded in mid-latitude westerly flow.
The NHC track forecast closely follows the HCCA consensus aid
during that period and is not too different from the previous
prediction. On days 4 and 5, the official forecast has been nudged
southward a bit based on the latest model trends.

Jerry continues to move in a direction directly into the shear
vector, and this orientation is unlikely to change at least for the
next 48 hours. After 48 hours, the storm's motion and shear vector
become more aligned, but then the storm will be moving over more
marginal sea surface temperatures and into a more stable
atmosphere. As a result, the intensity guidance has continued to
trend downward. The NHC forecast now only shows the possibility of
some slight strengthening, but overall the intensity is nearly
flatlined through day 5.

Thickness fields from the European, UKMET, and Canadian models
suggest that Jerry could start to become entangled in a frontal
boundary by Monday, and the Google DeepMind model loses a large
number of its ensemble members by Tuesday. Therefore, the NHC
forecast now shows Jerry becoming extratropical by Wednesday, if not
sooner. Only the GFS keeps Jerry as a tropical cyclone through day
5.


KEY MESSAGES:

1. Heavy rainfall will impact portions of the Leeward Islands,
British Virgin Islands, U.S. Virgin Islands, and Puerto Rico through
today, which could result in flash flooding, particularly in urban
areas and in steep terrain.

2. Swells generated by Jerry are affecting the Leeward Islands,
Windward Islands, the Virgin Islands, and Puerto Rico, and are
likely to cause life-threatening surf and rip current conditions.
These swells are expected to spread toward the rest of the Greater
Antilles today and tonight.


FORECAST POSITIONS AND MAX WINDS

INIT 10/1500Z 20.2N 63.4W 45 KT 50 MPH
12H 11/0000Z 22.1N 63.8W 45 KT 50 MPH
24H 11/1200Z 24.4N 63.7W 50 KT 60 MPH
36H 12/0000Z 26.9N 63.2W 50 KT 60 MPH
48H 12/1200Z 29.2N 62.7W 50 KT 60 MPH
60H 13/0000Z 30.8N 61.7W 50 KT 60 MPH
72H 13/1200Z 31.4N 59.7W 50 KT 60 MPH
96H 14/1200Z 30.4N 54.6W 50 KT 60 MPH
120H 15/1200Z 30.8N 47.9W 45 KT 50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Berg


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