Bertha Weaker...Barely a Tropical Storm...Future in Doubt

Tropical Storm Bertha Advisory Number 8
Nws National Hurricane Center Miami Fl
500 Pm Ast Sat Aug 02 2014

...Center Of Poorly Organized Bertha Moving Into The Eastern
Dominican Republic...

Summary Of 500 Pm Ast...2100 Utc...Information
Location...18.4n 68.5w
About 90 Mi...150 Km E Of Santo Domingo Dominican Republic
About 275 Mi...440 Km Se Of Grand Turk Island
Maximum Sustained Winds...45 Mph...75 Km/H
Present Movement...Wnw Or 300 Degrees At 22 Mph...35 Km/H
Minimum Central Pressure...1010 Mb...29.83 Inches

Watches And Warnings
Changes With This Advisory...

The Tropical Storm Warning Has Been Discontinued For The U. S. Virgin Islands.

The Government Of Antigua And Barbuda Has Discontinued The Tropical Storm Warning For The British Virgin Islands.

Summary Of Watches And Warnings In Effect...

A Tropical Storm Warning Is In Effect For...
* Puerto Rico
* Vieques
* Culebra
* The Eastern Dominican Republic From Cabo Frances Viejo To Isla Saona
* The Southeastern Bahamas...Including The Acklins...Crooked Island...Long Cay...The Inaguas... Mayaguana...And The Ragged Islands
* The Turks And Caicos Islands

A Tropical Storm Watch Is In Effect For...
* Central Bahamas...Including Cat Island...The Exumas...Long Island...Rum Cay ... And San Salvador

A Tropical Storm Warning Means That Tropical Storm Conditions Are Expected Somewhere Within The Warning Area...In This Case Within The Next 12 To 24 Hours.

A Tropical Storm Watch Means That Tropical Storm Conditions Are Possible Within The Watch Area...In This Case Within 24 To 36 Hours.

Interests Elsewhere Across Hispaniola And The Bahamas Should Monitor Bertha’s Progress.

Discussion And 48-Hour Outlook
At 500 Pm Ast...2100 Utc...The Center Of Tropical Storm Bertha Was Located Near Latitude 18.4 North...Longitude 68.5 West.

Bertha Is Moving Toward The West-Northwest Near 22 Mph...35 Km/H.

A Turn Toward The Northwest Is Expected Tonight...With This Motion Continuing Through Sunday Night.

A Turn Toward The North Is Expected On Monday.

On The Forecast Track...The Center Of Bertha Should Move Over The Eastern Portion Of The Dominican Republic Tonight...And Near Or Over The Southeastern Bahamas And Turks And Caicos Islands On Sunday.

Maximum Sustained Winds Have Decreased To Near 45 Mph...75 Km/H... With Higher Gusts.

Little Change In Strength Is Forecast Through Sunday.

Slow Strengthening Is Possible On Monday.

Tropical Storm Force Winds Extend Outward Up To 105 Miles...165 Km Mainly To The Northeast Of The Center.

The Estimated Minimum Central Pressure Is 1010 Mb...29.83 Inches.

Hazards Affecting Land
Tropical Storm Conditions Should Subside Over Puerto Rico During The Next Few Hours. Tropical Storm Conditions Are Expected Over The Eastern Dominican Republic This Afternoon And Tonight... And Are Expected In The Southeastern Bahamas And The Turks And Caicos Islands By Early Sunday. Tropical Storm Conditions Are Possible In The Watch Area In The Central Bahamas By Monday.

Bertha Is Expected To Produce Rainfall Amounts Of 1 To 3 Inches With Isolated Amounts Up To 5 Inches Across Portions Of The Leeward Islands...The U.S. And British Virgin Islands...Eastern Portions Of The Dominican Republic As Well As The Turks And Caicos Through Sunday Night. Rainfall Totals Of 3 To 5 Inches With Isolated Maximum Totals Of 8 Inches Are Possible Across Puerto Rico... With The Heaviest Totals Across The Southern And Eastern Portions Of The Island.

Next Advisory
Next Intermediate Advisory...800 Pm Ast.
Next Complete Advisory...1100 Pm Ast.

Forecaster Beven


Tropical Storm Bertha Discussion Number 8
Nws National Hurricane Center Miami Fl
500 Pm Ast Sat Aug 02 2014

Bertha Has Maintained Some Organized Convection Over The Eastern Semicircle During The Past Several Hours.

However, The System Barely Qualifies As A Tropical Cyclone, As A Combination Of Noaa Hurricane Hunter Aircraft And Surface Data Cannot Definitively Close Off The Circulation.

The Initial Intensity Is Reduced To 40 Kt Based On A Combination Of Surface Observations And Data From The San Juan Wsr-88d Doppler Radar.

It Should Be Noted That Bertha Continues To Suffer From Dry Air Entrainment And Northwesterly Vertical Shear, And Advisories Could Be Discontinued Tonight Or Sunday If The System Becomes Any Less Organized.

The Initial Motion Is Now 300/19.

Bertha Is Approaching The Southwestern Edge Of The Subtropical Ridge And Should Turn Northwestward During The Next Several Hours.

A Turn Toward The North Should Occur In About 48 Hours As Bertha Moves Between The Ridge And A Deep-Layer Trough Over The Southeastern United States.

After That, The Cyclone Should Turn Northeastward As It Enters The Mid-Latitude Westerlies.

The Track Guidance Remains In Good Agreement On This Scenario, And The New Forecast Track Is Again Generally Similar To The Previous Track.

There Are Now Three Possible Scenarios For The Intensity Of Bertha.

The Scenario For The Official Forecast Is That Bertha Survives Its Current Lack Of Structure, Land Interaction, And Dry Air Entrainment Long Enough To Reach A More Favorable Environment In About 36 Hours. At That Point, It Would Likely Intensify Until The Onset Of Extratropical Transition In 96-120 Hours. Using This Scenario, The New Intensity Forecast Is Similar To The Previous Forecast And Calls For Bertha To Become A Hurricane In About 96 Hours.

The Second Scenario Is That Bertha Degenerates To A Tropical Wave As It Passes Over Hispaniola, With Possible Regeneration Later When The System Reaches The More Favorable Environment.

A New Third Possibility Involves A Low Pressure Area Currently Developing Over The Northwestern Bahamas. The Ukmet And Navgem Forecast This Low To Get Strong Enough To Absorb Bertha In 48 Hours Or So, While The Other Models Are Less Bullish On The Its Development. Later Model Runs Should Help Determine The Likelihood Of This Scenario.

Forecast Positions And Max Winds

Init 02/2100z 18.4n 68.5w 40 Kt 45 Mph
12h 03/0600z 20.0n 70.3w 40 Kt 45 Mph
24h 03/1800z 22.5n 72.7w 40 Kt 45 Mph
36h 04/0600z 25.1n 74.1w 45 Kt 50 Mph
48h 04/1800z 28.0n 74.1w 50 Kt 60 Mph
72h 05/1800z 34.0n 70.5w 60 Kt 70 Mph
96h 06/1800z 38.5n 63.0w 65 Kt 75 Mph
120h 07/1800z 43.5n 53.0w 50 Kt 60 Mph

Forecaster Beven