Bertha Slightly Stronger But Remains Very Disorganized

Tropical Storm Bertha Advisory Number 3
Nws National Hurricane Center Miami Fl
1100 Am Ast Fri Aug 01 2014

Hurricane Hunter Aircraft Reports Bertha Slightly Stronger But Disorganized...

Summary Of 1100 Am Ast...1500 Utc...Information
Location...14.0n 58.9w
About 150 Mi...240 Km Ese Of Martinique
About 70 Mi...110 Km Ne Of Barbados
Maximum Sustained Winds...50 Mph...85 Km/H
Present Movement...Wnw Or 295 Degrees At 21 Mph...33 Km/H
Minimum Central Pressure...1008 Mb...29.77 Inches

Watches And Warnings
Changes With This Advisory...

The Government Of The Dominican Republic Has Issued A Tropical Storm Watch For The Eastern Dominican Republic From Cabo Frances Viejo To Isla Saona.

The Meteorological Service Of Barbados Has Discontinued All Warnings And Watches For Barbados ...St. Vincent...And The Grenadines.

Summary Of Watches And Warnings In Effect...

A Tropical Storm Warning Is In Effect For...
* St. Lucia
* Dominica
* Martinique
* Puerto Rico
* Vieques
* Culebra
* U.S. Virgin Islands
* British Virgin Islands

A Tropical Storm Watch Is In Effect For...
* The Eastern Dominican Republic From Cabo Frances Viejo To Isla Saona

A Tropical Storm Warning Means That Tropical Storm Conditions Are Expected Somewhere Within The Warning Area...In This Case Within The Next 24 Hours.

A Tropical Storm Watch Means That Tropical Storm Conditions Are Possible Within The Watch Area...Generally Within 48 Hours.

Interests Elsewhere Across The Northeastern Caribbean Sea And Hispaniola Should Monitor The Progress Of This System.

For Storm Information Specific To Your Area In The United States... Including Possible Inland Watches And Warnings...Please Monitor Products Issued By Your Local National Weather Service Forecast Office. For Storm Information Specific To Your Area Outside The United States...Please Monitor Products Issued By Your National Meteorological Service.

Discussion And 48-Hour Outlook
At 1100 Am Ast...1500 Utc...The Center Of Tropical Storm Bertha Was Located Near Latitude 14.0 North...Longitude 58.9 West.

Bertha Is Moving Toward The West-Northwest Near 21 Mph...33 Km/H...And This General Motion Is Expected To Continue For The Next Couple Of Days.

On The Forecast Track...Bertha Is Expected To Pass North Of Barbados During The Next Several Hours And Move Through The Central Lesser Antilles Tonight...And Approach The Virgin Islands And Puerto Rico On Saturday.

Reports From An Air Force Reserve Hurricane Hunter Aircraft Indicate That Maximum Sustained Winds Have Increased To Near 50 Mph... 85 Km/H...With Higher Gusts.

Upper-Level Winds Are Currently Not Favorable For Additional Strengthening...And Little Change In Strength Is Forecast During The Next 48 Hours.

Tropical Storm Force Winds Extend Outward Up To 115 Miles...185 Km Mainly To The Northeast Of The Center.

The Estimated Minimum Central Pressure Is 1008 Mb...29.77 Inches.

Hazards Affecting Land
Tropical Storm Conditions Are Expected To First Reach The Warning Area This Afternoon...Making Outside Preparations Difficult Or Dangerous. Tropical Storm Conditions Are Expected In Puerto Rico
And The Virgin Islands On Saturday.

Bertha Is Expected To Produce Rainfall Amounts Of 1 To 3 Inches With Isolated Amounts Up To 6 Inches Across Portions Of The Leeward Islands...As Well As The U. S. And British Virgin Islands. Rainfall Totals Of 3 To 6 Inches With Isolated Maximum Totals Of 10 Inches Are Possible Across Puerto Rico...With The Heaviest Totals Across The Southern Portion Of The Island.

Next Advisory
Next Intermediate Advisory...200 Pm Ast.
Next Complete Advisory...500 Pm Ast.

Forecaster Beven


Tropical Storm Bertha Discussion Number 3
Nws National Hurricane Center Miami Fl
1100 Am Ast Fri Aug 01 2014

Bertha Is Disorganized This Morning.

While Satellite Imagery Shows A Well-Defined Low-Cloud Swirl Exposed Just West Of The Main Convective Mass, Reports From An Air Force Reserve Hurricane Hunter Aircraft Show That The Wind Field More Resembles That Of An Open Wave. The Aircraft Did Report 56 Kt Winds At 1500 Feet To The East-Northeast Of The Center, Along With An Area Of Sfmr Surface Winds In Excess Of 40 Kt. Based On This, The Initial Intensity Is Increased To 45 Kt.

The Initial Motion Is Now 295/18, And Over The Past Few Hours Bertha May Be Moving Even Faster.

The Cyclone Is Currently Being Steered By The Flow Around The Atlantic Subtropical Ridge And This Should Continue For The Next 48 Hours Or So.

After That Time, The Cyclone Is Expected To Turn Northward Into A Break In The Ridge Caused By A Deep-Layer Trough Over The Eastern United States.

This Should Be Followed By Recurvature Into The Westerlies Over The Atlantic North Of Bermuda.

The Track Guidance Remains In Good Agreement With This Scenario, And It Has Changed Little Since The Previous Advisory. The New Forecast Track Is Therefore An Update Of The Previous Forecast.

Bertha Is Currently Experiencing About 15-20 Kt Of Southwesterly Vertical Wind Shear. And Water Vapor Imagery Shows Dry Mid- / Upper-Level Air Near The Storm.

The Forecast Track Calls For Bertha To Interact With One Or Two Upper-Level Troughs During The Next 48-72 Hours, Which Should Cause Some Shear And Dry Air Entrainment To Continue.

This, Combined With The Current Lack Of Organization, Suggests Little Change In Strength Should Occur During The Next 48 Hours Or So.

After That Time, Bertha Is Expected To Move Into An Environment Of Less Shear And Greater Moisture. The Intensity Forecast Calls For Modest Strengthening During That Time, But It Is Weaker Than All Of The Guidance Except The Florida State Superensemble.

An Alternative Scenario Is That A Combination Of Shear, Dry Air Entrainment, And Land Interaction Causes Bertha To Degenerate To A Tropical Wave During The Next 48 Hours, Followed By Possible Regeneration In The 72-120 Hours When The System Reaches The More Favorable Environment.

Forecast Positions And Max Winds

Init 01/1500z 14.0n 58.9w 45 Kt 50 Mph
12h 02/0000z 15.0n 61.5w 45 Kt 50 Mph
24h 02/1200z 16.6n 64.9w 45 Kt 50 Mph
36h 03/0000z 18.6n 67.6w 45 Kt 50 Mph
48h 03/1200z 20.9n 70.4w 45 Kt 50 Mph
72h 04/1200z 26.0n 74.0w 45 Kt 50 Mph
96h 05/1200z 31.5n 72.5w 50 Kt 60 Mph
120h 06/1200z 36.5n 65.0w 50 Kt 60 Mph

Forecaster Beven