Issued at 1100 PM AST WED AUG 27 2014
000
WTNT44 KNHC 280232
TCDAT4
HURRICANE CRISTOBAL DISCUSSION NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042014
1100 PM AST WED AUG 27 2014
Cristobal has a fairly circular area of deep convection over the
estimated low-level center, with cloud tops occasionally to -70 deg
C. The initial intensity is kept at 65 kt, in agreement with a
Dvorak estimate from TAFB. The symmetric appearance of the cloud
pattern suggests that vertical shear has not yet become very
strong, but the latest SHIPS guidance indicates a significant
increase in shear in 18-24 hours. The hurricane could strengthen
some over the next day or two as a tropical cyclone, or due to
baroclinic processes. The official intensity forecast is close to
the intensity model consensus through 36 hours, and a little above
it thereafter. Extratropical transition is likely to have occurred
by 48 hours since the global models depict the system as fully
embedded within a frontal zone by that time. Post-tropical Cristobal
is likely to be an intense extratropical cyclone with winds to
hurricane force over the north Atlantic in a couple of days.
The hurricane is beginning to accelerate northeastward, and the
motion estimate is 050/17. The track forecast is unchanged from
the previous advisory. Cristobal is currently rounding the
northwestern periphery of a subtropical anticyclone over the
west-central Atlantic. A mid-latitude shortwave trough to the
northwest of the hurricane should cause the hurricane, or its
post-tropical counterpart, to accelerate further and move into the
higher-latitude westerlies. The official forecast track is in good
agreement with the multi-model consensus TVCA.
The track, intensity and wind structure forecasts have been
coordinated with the Ocean Prediction Center.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0300Z 34.1N 69.9W 65 KT 75 MPH
12H 28/1200Z 36.1N 66.6W 65 KT 75 MPH
24H 29/0000Z 39.3N 59.6W 70 KT 80 MPH
36H 29/1200Z 43.4N 51.5W 75 KT 85 MPH
48H 30/0000Z 47.5N 44.5W 70 KT 80 MPH...POST-TROP/EXTRATROP
72H 31/0000Z 56.0N 32.0W 65 KT 75 MPH...POST-TROP/EXTRATROP
96H 01/0000Z 62.5N 25.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 02/0000Z...ABSORBED
$$
Forecaster Pasch
Continue reading...
000
WTNT44 KNHC 280232
TCDAT4
HURRICANE CRISTOBAL DISCUSSION NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042014
1100 PM AST WED AUG 27 2014
Cristobal has a fairly circular area of deep convection over the
estimated low-level center, with cloud tops occasionally to -70 deg
C. The initial intensity is kept at 65 kt, in agreement with a
Dvorak estimate from TAFB. The symmetric appearance of the cloud
pattern suggests that vertical shear has not yet become very
strong, but the latest SHIPS guidance indicates a significant
increase in shear in 18-24 hours. The hurricane could strengthen
some over the next day or two as a tropical cyclone, or due to
baroclinic processes. The official intensity forecast is close to
the intensity model consensus through 36 hours, and a little above
it thereafter. Extratropical transition is likely to have occurred
by 48 hours since the global models depict the system as fully
embedded within a frontal zone by that time. Post-tropical Cristobal
is likely to be an intense extratropical cyclone with winds to
hurricane force over the north Atlantic in a couple of days.
The hurricane is beginning to accelerate northeastward, and the
motion estimate is 050/17. The track forecast is unchanged from
the previous advisory. Cristobal is currently rounding the
northwestern periphery of a subtropical anticyclone over the
west-central Atlantic. A mid-latitude shortwave trough to the
northwest of the hurricane should cause the hurricane, or its
post-tropical counterpart, to accelerate further and move into the
higher-latitude westerlies. The official forecast track is in good
agreement with the multi-model consensus TVCA.
The track, intensity and wind structure forecasts have been
coordinated with the Ocean Prediction Center.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0300Z 34.1N 69.9W 65 KT 75 MPH
12H 28/1200Z 36.1N 66.6W 65 KT 75 MPH
24H 29/0000Z 39.3N 59.6W 70 KT 80 MPH
36H 29/1200Z 43.4N 51.5W 75 KT 85 MPH
48H 30/0000Z 47.5N 44.5W 70 KT 80 MPH...POST-TROP/EXTRATROP
72H 31/0000Z 56.0N 32.0W 65 KT 75 MPH...POST-TROP/EXTRATROP
96H 01/0000Z 62.5N 25.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 02/0000Z...ABSORBED
$$
Forecaster Pasch
Continue reading...