ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM DOLORES DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL EP052015 400 PM CDT SUN JUL 12 2015 There has been no significant change in Dolores' organization during the past several hours. Satellite imagery continues to show most of the cyclone's deep convection remaining in a band over the northeastern semicircle of the circulation. This convective asymmetry is likely related to some west-northwesterly shear as diagnosed by UW-CIMSS and SHIPS shear analyses. An ASCAT-B pass showed the center barely underneath the convective mass, with peak uncontaminated winds around 45 kt. Based on the ASCAT data, the initial intensity is raised to 45 kt. The ASCAT pass showed the center of Dolores to be a bit farther south than previous estimates, and the heading is estimated to be more westerly or 295/09. A subtropical ridge over the south-central United States should guide Dolores generally west-northwestward with a decrease in forward speed during the next 48 hours. The cyclone's heading should become more northwesterly by 72 hours, when Dolores reaches the western periphery of the ridge. Later in the forecast period, Dolores' track should bend back toward the west- northwest as the subtropical ridge reasserts itself. The official track forecast is similar to but a little to the left of the previous one through 48 hours and slightly to the right after that. The track forecast after 48 hours is near a multi-model consensus that excludes the GFDL solution which unrealistically takes Dolores toward the Baja California peninsula. Thermodynamic variables in the near-storm environment are quite conducive for intensification, with sea surface temperatures of 29-30 deg C and plenty of deep-layer moisture. Some west- northwesterly shear is forecast to persist and perhaps even increase over the next day or so before decreasing from 72 hours through the remainder of the forecast period. However, the shear is not expected to be strong enough to impede steady intensification. With a sharp gradient in SSTs along 20N, the intensity late in the period is very much dependent on how much latitude Dolores gains by that time. The NHC intensity forecast is about the same as the previous one and is very similar to the multi-model consensus (ICON) through 48 hours but above ICON after that, closest to the SHIPS model guidance. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 15.6N 103.0W 45 KT 50 MPH 12H 13/0600Z 16.2N 104.5W 55 KT 65 MPH 24H 13/1800Z 16.8N 106.0W 65 KT 75 MPH 36H 14/0600Z 17.2N 107.1W 75 KT 85 MPH 48H 14/1800Z 17.7N 108.0W 80 KT 90 MPH 72H 15/1800Z 18.9N 109.7W 95 KT 110 MPH 96H 16/1800Z 20.0N 112.0W 90 KT 105 MPH 120H 17/1800Z 20.9N 114.9W 85 KT 100 MPH $$ Forecaster Kimberlain NNNN