Hurricane Lorenzo Forecast Discussion Number 14

By | September 26, 2019

Issued at 500 AM AST Thu Sep 26 2019

WTNT43 KNHC 260842

Hurricane Lorenzo Discussion Number  14
NWS National Hurricane Center Miami FL       AL132019
500 AM AST Thu Sep 26 2019

Lorenzo's satellite appearance continues to steadily improve. The
cyclone has a large central dense overcast, with outflow established
in all quadrants. The hurricane has at times shown signs of a
developing eye, however, it has been mostly obscured during the last
few hours by expanding cloud tops associated with central (and
likely eyewall) convection. Although the eye is not yet apparent in
geostationary imagery, a 0618 UTC SSMIS overpass showed that Lorenzo
has developed a well-defined mid-level eye. TAFB and SAB Dvorak
classifications both support an intensity of 90 kt but objective
estimates are lower. The intensity of Lorenzo is therefore held at
85 kt as a compromise of the higher subjective and lower objective
assessments, but this could be a little conservative.

The hurricane is still moving west-northwestward, but a turn toward
the northwest is expected later today. Lorenzo has reached a break
in the subtropical ridge to the north and should now begin to gain
latitude at a faster rate. By day 3, the global models show Lorenzo
moving northward along the western periphery of the ridge and by the
end of the period it will likely turn northeastward and accelerate
ahead of an approaching deep-layer trough. While the models still
differ on the details of the forecast, like how fast Lorenzo will be
moving once it turns northward, they all show this general
evolution. The NHC forecast is mostly an update of the previous
advisory and is just west of the center of the guidance envelope.

Lorenzo has several more days during which it could strengthen. The
primary limiting factor appears to be the size of Lorenzo, which is
considerable and is forecast to increase. This will likely only slow
down Lorenzo's strengthening, not prevent it. By 72 h, Lorenzo could
experience an increase in shear, and most of the guidance responds
by forecasting very slow weakening. The official intensity forecast
is generally close to HCCA and IVCN at all lead times and is not
very different from the previous forecast.


INIT  26/0900Z 15.1N  39.3W   85 KT 100 MPH
 12H  26/1800Z 16.0N  40.6W  100 KT 115 MPH
 24H  27/0600Z 17.7N  41.9W  105 KT 120 MPH
 36H  27/1800Z 19.5N  43.0W  105 KT 120 MPH
 48H  28/0600Z 21.2N  43.8W  105 KT 120 MPH
 72H  29/0600Z 24.6N  43.5W  100 KT 115 MPH
 96H  30/0600Z 28.0N  42.0W  100 KT 115 MPH
120H  01/0600Z 33.0N  38.0W   95 KT 110 MPH

Forecaster Zelinsky

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