Eastern Pacific Basin Tropical Cyclones

Hurricane Blas Forecast Discussion


608 
WTPZ42 KNHC 161437
TCDEP2

Hurricane Blas Discussion Number  10
NWS National Hurricane Center Miami FL       EP022022
1000 AM CDT Thu Jun 16 2022

The satellite presentation of Blas in geostationary imagery has not 
changed much this morning with the center embedded within the 
northern portion of the central dense overcast. Recent microwave 
imagery, however, shows that there has been some additional 
degradation of the inner-core due to moderate east-northeasterly 
shear. There is a bit more uncertainty than normal in the initial 
intensity of the hurricane as the subjective Dvorak estimates are 
on the higher end at 77 and 90 kt, while objective satellite 
estimates from the ADT and SATCON are lower at 70 and 64 kt, 
respectively.  The advisory intensity is kept near a consensus of 
these estimates at 75 kt. 

Although the shear is forecast to relax slightly during the next 
12-24 hours, the recent degradation of the inner core will likely 
prevent any further intensification.  Therefore, little change in 
strength is anticipated through tomorrow morning.  By 36 hours, Blas 
is forecast to cross the 26 degree Celsius isotherm which should 
commence the weakening process.  Steady weakening is then 
anticipated during the remainder of the forecast period while Blas 
moves into less favorable thermodynamic conditions, and the cyclone 
is forecast to degenerate into a remnant low by day 4.  The NHC 
intensity prediction is in best agreement with the LGEM model and 
ICON consensus aid. 

The initial motion estimate is west-northwestward or 290/7 kt. A 
mid-level ridge to the north of the hurricane should continue to 
steer the cyclone west-northwestward with some increase in forward 
speed over the next 48-72 hours.  After that time, a weaker and more 
shallow Blas is likely to turn westward or west-southwestward within 
the lower-level tradewind flow. There is very little cross-track 
spread among the various dynamical models, but there is some 
along-track or speed differences with the HWRF, HMON, and GFS much 
faster than the ECMWF.  The new NHC track forecast is a little 
faster than the previous advisory, closer to the latest HCCA and 
TVCE consensus aids, but additional adjustments could be required in 
subsequent advisories. 

While Blas is expected to remain off the coast of Mexico, its
associated swells are affecting portions of the coast of 
southwestern Mexico and are expected to spread to portions of the 
southern Baja California peninsula by late Friday. These swells are 
likely to cause dangerous surf and rip current conditions in those 
areas through the weekend. 


FORECAST POSITIONS AND MAX WINDS

INIT  16/1500Z 15.9N 104.8W   75 KT  85 MPH
 12H  17/0000Z 16.5N 106.0W   75 KT  85 MPH
 24H  17/1200Z 17.3N 108.2W   75 KT  85 MPH
 36H  18/0000Z 18.0N 110.4W   65 KT  75 MPH
 48H  18/1200Z 18.4N 112.1W   55 KT  65 MPH
 60H  19/0000Z 18.8N 113.2W   45 KT  50 MPH
 72H  19/1200Z 19.0N 114.3W   35 KT  40 MPH
 96H  20/1200Z 18.7N 116.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  21/1200Z 18.5N 118.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown




Source link