ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Tropical Storm Norma Discussion Number 4 NWS National Hurricane Center Miami FL EP172017 300 AM MDT Fri Sep 15 2017 The cloud pattern continues to be well organized and convection has been gradually increasing, primarily in a band to the east of the center. Dvorak T-numbers and an ASCAT pass over the cyclone indicate that the initial intensity is 45 kt. With low shear prevailing and Norma moving over warm waters, gradual strengthening is forecast. Norma is expected to become a hurricane before it approaches the Baja California peninsula. Norma appears to be moving very slowly toward the north at about 2 kt. Steering currents are weak and are provided by a weak ridge of high pressure over Mexico. This flow is not expected to change much, so Norma should continue to move very slowly. There was a change in track guidance tonight, and most of the models shifted a little bit westward, primarily beyond 3 days. On this basis, the NHC forecast was also adjusted westward. The latter portion of the forecast, however, is highly uncertain since the track models diverge significantly. The NHC track forecast follows the HFIP corrected consensus, HCCA, and the multi-model simple consensus as well. A Hurricane Watch will likely be necessary for portions of the southern Baja California peninsula later today. FORECAST POSITIONS AND MAX WINDS INIT 15/0900Z 18.6N 109.7W 45 KT 50 MPH 12H 15/1800Z 19.0N 109.8W 50 KT 60 MPH 24H 16/0600Z 19.4N 110.0W 60 KT 70 MPH 36H 16/1800Z 20.0N 110.1W 70 KT 80 MPH 48H 17/0600Z 20.6N 110.3W 70 KT 80 MPH 72H 18/0600Z 22.8N 111.4W 70 KT 80 MPH 96H 19/0600Z 24.5N 112.0W 50 KT 60 MPH 120H 20/0600Z 26.3N 110.7W 35 KT 40 MPH $$ Forecaster Avila NNNN
Alternate Formats
About Alternates -
E-Mail Advisories -
RSS Feeds
Cyclone Forecasts
Latest Advisory -
Past Advisories -
About Advisories
Marine Forecasts
Latest Products -
About Marine Products
Tools & Data
Satellite Imagery -
US Weather Radar -
Aircraft Recon -
Local Data Archive -
Forecast Verification -
Deadliest/Costliest/Most Intense
Learn About Hurricanes
Storm Names
Wind Scale -
Prepare -
Climatology -
NHC Glossary -
NHC Acronyms -
Frequently Asked Questions -
AOML Hurricane-Research Division
About Us
About NHC -
Mission/Vision -
Other NCEP Centers -
NHC Staff -
Visitor Information -
NHC Library
NOAA/
National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Sunday, 31-Dec-2017 12:10:38 UTC