ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Tropical Storm Blanca Discussion Number 12 NWS National Hurricane Center Miami FL EP022021 900 AM MDT Wed Jun 02 2021 Similar to yesterday, deep convective activity has waned with Blanca this morning as the cyclone continues to be impacted by dry-air entrainment imported by high west-southwesterly vertical wind shear. The low-level center is once again becoming exposed to the west of the convective cloud mass. While there has not been any helpful overnight scatterometer passes, an earlier 0844 UTC AMSR-2 microwave pass suggested that the low-level circulation is gradually becoming more diffuse, with several possible low level swirls embedded within. The latest subjective Dvorak estimates are T2.0/35 kt from SAB and T3.0/45 kt from TAFB, while the most recent UW-CIMSS Advanced Dvorak Technique (ADT) estimate was 34 kt. The current intensity estimate was held at 40 kt for this advisory. Even though current sea surface temperatures remain sufficently warm underneath the cyclone (27-28 C), low-level, cold-air stratocumulus clouds can be seen on first-light visible imagery being entrained into the low-level circulation of Blanca. Strong vertical wind shear will continue over the next few days as sea surface temperatures decrease and the environment aloft becomes drier and more stable. While diurnal convective bursts are still likely to occur during this time, they will become less organized and more intermittent as the cyclone succumbs to the increasingly stable environment. The official NHC intensity forecast still calls for Blanca to become a tropical depression by Thursday and a remnant low by this weekend, which is in close agreement with the intensity guidance. After a minor northward position adjustment, Blanca appears to still be on a west-northwestward heading, albeit somewhat slower than earlier, at 300/4 kt. A westward turn is expected over the next 24 hours as Blanca becomes a shallow cyclone and is mainly steered by the low-level easterly trade wind flow. The latest NHC track forecast is somewhat further north than the previous forecast early on, but by the end of the forecast period is very close to the previous forecast track, and lies close to the HCCA consensus aid. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 15.5N 112.2W 40 KT 45 MPH 12H 03/0000Z 15.6N 112.8W 35 KT 40 MPH 24H 03/1200Z 15.6N 113.5W 30 KT 35 MPH 36H 04/0000Z 15.4N 114.8W 30 KT 35 MPH 48H 04/1200Z 15.3N 116.0W 25 KT 30 MPH 60H 05/0000Z 15.3N 117.4W 25 KT 30 MPH 72H 05/1200Z 15.3N 118.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 06/1200Z 15.3N 120.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 07/1200Z...DISSIPATED $$ Forecaster Papin/Stewart NNNN