Tropical Storm Frank Discussion Number 27
NWS National Hurricane Center Miami FL EP072022
200 PM PDT Mon Aug 01 2022
Frank's convection continues to fade as it maintains its trek over
cooler waters. In response, both subjective and objective Dvorak
numbers are decreasing. In addition, we received a direct overhead
ASCAT-B pass at 1820 UTC, which showed a peak wind retrieval of
43-kt in the northern semicircle of the storm. Assuming a little
undersampling from this instrument, the intensity was reduced to 45
kt this advisory, favoring the lower end of Dvorak estimates.
Frank is still moving northwestward at 310/10 kt. There is little
change in the track reasoning this cycle. Frank's track should
gradually bend more poleward as it becomes a shallow vortex and is
steered by the southerly flow ahead of a deep-layer trough. The
latest NHC track forecast remains near the consensus aids, and is
just a touch left of the previous forecast.
Sea surface temperatures under the storm are already down to 22 C
and only cool further along the forecast track. The latest model
output from the GFS, ECMWF, CMC, and HWRF all suggest the remaining
convection will fizzle out over the next 24 hours. The latest
forecast now shows Frank becoming a post-tropical cyclone by that
time-frame. It will take another few days for the large wind
field of Frank to spin down enough for it to open up into a
trough. This is expected to occur by Friday, well offshore
southeastward of coastal California.
FORECAST POSITIONS AND MAX WINDS
INIT 01/2100Z 22.8N 123.4W 45 KT 50 MPH
12H 02/0600Z 24.0N 124.5W 40 KT 45 MPH
24H 02/1800Z 25.5N 125.8W 35 KT 40 MPH...POST-TROPICAL
36H 03/0600Z 27.4N 126.8W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 03/1800Z 29.4N 127.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 04/0600Z 31.4N 127.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 04/1800Z 33.0N 127.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 05/1800Z...DISSIPATED
$$
Forecaster Papin
NWS National Hurricane Center Miami FL EP072022
200 PM PDT Mon Aug 01 2022
Frank's convection continues to fade as it maintains its trek over
cooler waters. In response, both subjective and objective Dvorak
numbers are decreasing. In addition, we received a direct overhead
ASCAT-B pass at 1820 UTC, which showed a peak wind retrieval of
43-kt in the northern semicircle of the storm. Assuming a little
undersampling from this instrument, the intensity was reduced to 45
kt this advisory, favoring the lower end of Dvorak estimates.
Frank is still moving northwestward at 310/10 kt. There is little
change in the track reasoning this cycle. Frank's track should
gradually bend more poleward as it becomes a shallow vortex and is
steered by the southerly flow ahead of a deep-layer trough. The
latest NHC track forecast remains near the consensus aids, and is
just a touch left of the previous forecast.
Sea surface temperatures under the storm are already down to 22 C
and only cool further along the forecast track. The latest model
output from the GFS, ECMWF, CMC, and HWRF all suggest the remaining
convection will fizzle out over the next 24 hours. The latest
forecast now shows Frank becoming a post-tropical cyclone by that
time-frame. It will take another few days for the large wind
field of Frank to spin down enough for it to open up into a
trough. This is expected to occur by Friday, well offshore
southeastward of coastal California.
FORECAST POSITIONS AND MAX WINDS
INIT 01/2100Z 22.8N 123.4W 45 KT 50 MPH
12H 02/0600Z 24.0N 124.5W 40 KT 45 MPH
24H 02/1800Z 25.5N 125.8W 35 KT 40 MPH...POST-TROPICAL
36H 03/0600Z 27.4N 126.8W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 03/1800Z 29.4N 127.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 04/0600Z 31.4N 127.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 04/1800Z 33.0N 127.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 05/1800Z...DISSIPATED
$$
Forecaster Papin