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TROPICAL STORM BERTHA DISCUSSION NUMBER   4
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT MON AUG 05 2002

RADAR OBSERVATIONS SUGGEST THAT THE POORLY-DEFINED CENTER HAS
WOBBLED NORTH-NORTHWESTWARD OVER THE PAST FEW HOURS.  HOWEVER SINCE
THERE IS A LARGE MID-TROPOSPHERIC ANTICYCLONE TO THE NORTH OF
BERTHA...A GENERAL WEST-NORTHWESTWARD MOTION IS LIKELY DURING THE
NEXT DAY OR SO.  GLOBAL MODEL GUIDANCE INDICATES A WEAK 500 MB HIGH
DEVELOPING OVER THE GULF OF MEXICO...AND THIS MAY TEND TO BLOCK THE
FORWARD PROGRESS OF THE CYCLONE.  THE OFFICIAL FORECAST CALLS FOR A
RATHER SLOW FORWARD SPEED...AND IS IN REASONABLE AGREEMENT WITH THE
CURRENT GFS OUTPUT.  THE GFDL IS SOMEWHAT FASTER AND TAKES
BERTHA...OR ITS REMNANTS...OVER TEXAS IN 36 HOURS.

THE CENTER HAS NOT MOVED THAT FAR INLAND YET...AND IS SITUATED OVER 
A RATHER SWAMPY SURFACE.  THEREFORE WEAKENING SHOULD BE SLOW TO 
OCCUR.  DOPPLER RADAR DATA STILL SHOW SOME SPOTS OF TROPICAL STORM 
FORCE WINDS ALOFT...AT ABOUT 1000 FEET.  DEEP CONVECTION HAS 
INCREASED OVER THE EASTERN PORTION OF THE CIRCULATION...SO THERE IS 
STILL THE POSSIBILITY OF TROPICAL STORM FORCE WINDS IN SQUALLS AT 
THE SURFACE.  THEREFORE BERTHA IS BEING KEPT AS A TROPICAL STORM FOR 
THIS ADVISORY.  HOWEVER THE SYSTEM SHOULD WEAKEN TO A DEPRESSION 
RATHER SOON.

THE MAIN CONCERN WITH BERTHA IS RAINFALL AND THE THREAT OF INLAND 
FLOODING...WHICH COULD BECOME MORE OF A PROBLEM IF THE CYCLONE MOVES 
EVEN MORE SLOWLY THAN FORECAST. 

FORECASTER PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     05/0900Z 29.8N  89.9W    35 KTS...INLAND
12HR VT     05/1800Z 30.2N  91.0W    30 KTS...INLAND 
24HR VT     06/0600Z 30.5N  92.0W    25 KTS...INLAND AND DISSIPATING
36HR VT     06/1800Z 30.8N  93.0W    20 KTS...INLAND AND DISSIPATING
48HR VT     07/0600Z...INLAND AND DISSIPATED
 
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