Tropical Storm Erin Struggling in Mid Atlantic

Tropical Storm Erin Advisory Number 10
Nws National Hurricane Center Miami Fl
500 Am Ast Sat Aug 17 2013

...Erin Still A Tropical Storm...

Summary Of 500 Am Ast...0900 Utc...Information
Location...18.9n 35.6w
About 790 Mi...1270 Km Wnw Of The Cape Verde Islands
Maximum Sustained Winds...40 Mph...65 Km/H
Present Movement...Wnw Or 300 Degrees At 15 Mph...24 Km/H
Minimum Central Pressure...1006 Mb...29.71 Inches

Watches And Warnings
There Are No Coastal Watches Or Warnings In Effect.

Discussion And 48-Hour Outlook
At 500 Am Ast...0900 Utc...The Center Of Tropical Storm Erin Was
Located Near Latitude 18.9 North...Longitude 35.6 West.

Erin Is Moving Toward The West-Northwest Near 15 Mph...24 Km/H...And This Motion Is Expected To Continue With A Gradual Decrease In Forward Speed During The Next Couple Of Days.

Maximum Sustained Winds Are Near 40 Mph...65 Km/H...With Higher
Gusts. Little Change In Strength Is Forecast Today...With Some
Weakening Expected To Begin On Sunday.

Tropical Storm Force Winds Extend Outward Up To 70 Miles...110 Km
From The Center.

The Estimated Minimum Central Pressure Is 1006 Mb...29.71 Inches.

Hazards Affecting Land

Tropical Storm Erin Discussion Number 10
Nws National Hurricane Center Miami Fl
500 Am Ast Sat Aug 17 2013

The Center Of Erin Is At Least Partly Exposed Near The Southwestern
Edge Of The Main Convective Cluster Due To 15 Kt Of Southwesterly
Vertical Wind Shear...And The Convection Is Somewhat Farther From
The Center Than 6 Hours Ago. There Is No Recent Data From Near The Center...So The Initial Intensity Is Held At 35 Kt...Which Is Above
The Satellite Intensity Estimates From Tafb And Sab.

The Initial Motion Is 300/13. There Is No Change To The Track
Forecast Philosophy From The Previous Advisory.

A Gradually Strengthening Subtropical Ridge Should Steer Erin Generally West-Northwestward For The Next 24-36 Hour. This Should Be Followed By A Turn More To The Left Around A Stronger Low-Level Ridge Through 72h.

Thereafter...A Turn Back To The Northwest Is Forecast When Erin...Or Its Remnants...Moves Toward A Break In The Ridge Between 50w-60w. The New Forecast Track Is Shifted A Little To The North Of The Previous Track In Best Agreement With The Ecmwf... Ukmet... Canadian..And Navgem Models. The Track Lies Well To The Left Of The Gfs...Which Recurves Erin Through The Break In The Ridge.

Erin Is Currently Over Sea Surface Temperatures Of 25c-26c. While
The Forecast Track Takes The Cyclone Over Warmer Water...The
Cyclone Is Moving Into A Very Dry Mid/Upper-Level Air Mass As Seen
In Water Vapor And Meteosat Air Mass Imagery.

In Addition...The Southwesterly Shear Is Expected To Gradually Increase During The Forecast Period.

The New Intensity Forecast Is The Same As The Previous Forecast In Calling For Erin To Weaken To A Depression In About 36 Hours And To Degenerate To A Remnant Low In About 96 Hours.

An Alternative Scenario Is That Erin Dissipates Earlier Than Currently Forecast...As Shown By All Of The Global Models Except The Gfs.

Forecast Positions And Max Winds

Init 17/0900z 18.9n 35.6w 35 Kt 40 Mph
12h 17/1800z 19.7n 37.1w 35 Kt 40 Mph
24h 18/0600z 20.4n 38.9w 35 Kt 40 Mph
36h 18/1800z 20.9n 40.8w 30 Kt 35 Mph
48h 19/0600z 21.4n 43.1w 30 Kt 35 Mph
72h 20/0600z 23.0n 48.0w 30 Kt 35 Mph
96h 21/0600z 25.5n 52.0w 25 Kt 30 Mph...Post-Trop/Remnt Low
120h 22/0600z...Dissipated

Forecaster Beven