TROPICAL STORM HOWARD DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092016
200 AM PDT WED AUG 03 2016
Deep convection associated with Howard has continued to decrease
and become separated from the low-level center overnight. Several
microwave overpasses since the previous advisory and recent ASCAT
data have been extremely helpful in locating the center, which is
displaced well south of the remaining area of cold cloud tops. The
initial wind speed has been reduced to 40 kt, which is based on the
scatterometer data that revealed 35 to 40 kt winds over the
northeastern portion of the circulation.
Howard is moving west-northwestward or 290/13 kt. The track
forecast philosophy remains the same as the previous advisory. The
tropical storm should move west-northwestward to the south of a
subtropical ridge today, then turn westward by Thursday as the
cyclone weakens and comes under the influence of the low-level
easterly trades. The model guidance is in good agreement on
this scenario, but has generally shifted southward at days 4 and
5. The NHC track has been adjusted accordingly, but it remains near
the middle of the guidance envelope.
The tropical storm should continue to weaken during the next day or
so while it moves over cool water and into a drier and more stable
environment. Howard is forecast to become a remnant low in 24 to
36 hours, but this could occur sooner if organized deep convection
does not redevelop later today. The cyclone will be move over
slightly warm waters after 48 hours, but increasing shear and
unfavorable thermodynamic conditions should prevent
restrengthening.
FORECAST POSITIONS AND MAX WINDS
INIT 03/0900Z 20.3N 132.6W 40 KT 45 MPH
12H 03/1800Z 21.0N 134.7W 35 KT 40 MPH
24H 04/0600Z 21.7N 137.5W 30 KT 35 MPH
36H 04/1800Z 22.1N 140.4W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 05/0600Z 22.3N 143.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 06/0600Z 22.5N 148.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 07/0600Z 22.3N 153.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 08/0600Z 21.8N 158.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
$$
Forecaster Brown
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092016
200 AM PDT WED AUG 03 2016
Deep convection associated with Howard has continued to decrease
and become separated from the low-level center overnight. Several
microwave overpasses since the previous advisory and recent ASCAT
data have been extremely helpful in locating the center, which is
displaced well south of the remaining area of cold cloud tops. The
initial wind speed has been reduced to 40 kt, which is based on the
scatterometer data that revealed 35 to 40 kt winds over the
northeastern portion of the circulation.
Howard is moving west-northwestward or 290/13 kt. The track
forecast philosophy remains the same as the previous advisory. The
tropical storm should move west-northwestward to the south of a
subtropical ridge today, then turn westward by Thursday as the
cyclone weakens and comes under the influence of the low-level
easterly trades. The model guidance is in good agreement on
this scenario, but has generally shifted southward at days 4 and
5. The NHC track has been adjusted accordingly, but it remains near
the middle of the guidance envelope.
The tropical storm should continue to weaken during the next day or
so while it moves over cool water and into a drier and more stable
environment. Howard is forecast to become a remnant low in 24 to
36 hours, but this could occur sooner if organized deep convection
does not redevelop later today. The cyclone will be move over
slightly warm waters after 48 hours, but increasing shear and
unfavorable thermodynamic conditions should prevent
restrengthening.
FORECAST POSITIONS AND MAX WINDS
INIT 03/0900Z 20.3N 132.6W 40 KT 45 MPH
12H 03/1800Z 21.0N 134.7W 35 KT 40 MPH
24H 04/0600Z 21.7N 137.5W 30 KT 35 MPH
36H 04/1800Z 22.1N 140.4W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 05/0600Z 22.3N 143.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 06/0600Z 22.5N 148.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 07/0600Z 22.3N 153.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 08/0600Z 21.8N 158.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
$$
Forecaster Brown