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Tropical Storm Irwin Discussion Number 40
NWS National Hurricane Center Miami FL EP102017
200 AM PDT Tue Aug 01 2017
Irwin stubbornly remains a tropical cyclone this morning. The
systems continues to produce a small area of deep convection near
the center despite being over SSTs of around 22 deg C. The
convection has gradually waned over the past 24 hours, but recent
ASCAT data indicate that the maximum winds remain around 40 kt.
Irwin should lose all of its remaining convection later today, and
should become post-tropical within the next 12 to 24 hours while it
moves over even colder waters. As a result, the system is forecast
to gradually spin down, with the remnant circulation dissipating in
2 to 3 days.
A mid-level high pressure area to the northeast of Irwin continues
to steer the cyclone north-northwestward. This general motion is
forecast to continue this morning. As Irwin weakens and becomes a
shallow system, it should slow down and turn northwestward. The
track guidance remains in agreement on this scenario and no
significant change to the previous forecast was required.
FORECAST POSITIONS AND MAX WINDS
INIT 01/0900Z 24.9N 128.8W 40 KT 45 MPH
12H 01/1800Z 26.2N 129.7W 30 KT 35 MPH
24H 02/0600Z 27.5N 130.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 02/1800Z 28.4N 131.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 03/0600Z 29.2N 132.6W 15 KT 15 MPH...POST-TROP/REMNT LOW
72H 04/0600Z...DISSIPATED
$$
Forecaster Brown
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