ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Blanca Discussion Number 7
NWS National Hurricane Center Miami FL EP022021
300 AM MDT Tue Jun 01 2021
Blanca's satellite appearance has changed little tonight, as the
cyclone has maintained deep convection near its center with a couple
of banding elements observed in recent imagery. Overnight ASCAT data
indicate Blanca remains a compact tropical cyclone with a small
radius of tropical-storm-force winds. The 35-40 kt winds shown by
the scatterometer are likely not representative of the cyclone's
peak intensity given the small size of the wind field. The initial
advisory intensity of 50 kt is supported by a blend of the objective
UW-CIMSS ADT and SATCON intensity estimates and subjective Dvorak
classifications of T3.5/55 kt from SAB and T3.0/45 kt from TAFB.
The cyclone's estimated motion is 305/6 kt, as it continues to move
around the southwestern extent of a mid-level ridge that extends
across central Mexico. A mid- to upper-level trough near the Baja
California peninsula is beginning to weaken the steering ridge, and
so Blanca is expected to move generally west-northwestward with a
continued decrease in forward speed over the next couple of days.
Afterwards, the system is forecast to slowly turn westward within
the low-level trade winds as it weakens and becomes vertically
shallow. The latest NHC forecast track is largely an update of the
previous one and remains close to the HCCA corrected consensus aid.
Blanca has a brief window today for some additional strengthening,
although the vertical wind shear may already be increasing over the
system. By tonight, increasing southwesterly or west-southwesterly
shear should induce a weakening trend that will likely continue
through late this week. As Blanca moves into an environment with
cooler sea surface temperatures and drier mid-level air in 2-3 days,
the cyclone is forecast to weaken to a depression by 72 hours and a
remnant low by the end of the forecast period, if not sooner. Once
again, the NHC intensity forecast captures the overall trend
reflected by the HCCA and ICON consensus aids.
FORECAST POSITIONS AND MAX WINDS
INIT 01/0900Z 14.2N 109.6W 50 KT 60 MPH
12H 01/1800Z 14.6N 110.5W 55 KT 65 MPH
24H 02/0600Z 15.1N 111.5W 50 KT 60 MPH
36H 02/1800Z 15.5N 112.3W 45 KT 50 MPH
48H 03/0600Z 15.7N 112.8W 40 KT 45 MPH
60H 03/1800Z 15.9N 113.5W 35 KT 40 MPH
72H 04/0600Z 16.0N 114.4W 30 KT 35 MPH
96H 05/0600Z 16.0N 116.4W 25 KT 30 MPH
120H 06/0600Z 16.1N 118.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
$$
Forecaster Reinhart/Beven
NNNN