HOME	ARCHIVES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM BERTHA SPECIAL DISCUSSION NUMBER   2
NATIONAL WEATHER SERVICE MIAMI FL
630 PM CDT SUN AUG 04 2002
 
AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT FOUND 5000 FT 
FLIGHT-LEVEL WINDS OF 47 KT AND A CENTRAL PRESSURE OF 1009 MB 
AROUND 2300Z. THE SOUTH BILOXI BUOY ALSO REPORTED 10-MINUTE AVERAGE 
WINDS OF 33 KT WITH GUSTS TO 41 KT AT ABOUT THE SAME TIME. AS 
SUCH...TROPICAL DEPRESSION TWO IS BEING UPGRADED TO TROPICAL STORM 
BERTHA.
 
THE INITIAL MOTION ESTIMATE IS 315/06 BASED ON RADAR DATA AND THE 
TWO RECON FIXES. BERTHA IS EXPECTED TO TRACK NORTHWEST FOR THE NEXT 
12 HOURS OR SO AND THEN TURN MORE TOWARD THE WEST-NORTHWEST AFTER 
THAT AS LOW- TO MID-LEVEL RIDGING INCREASES FROM THE EAST. ON THIS 
TRACK...BERTHA IS EXPECTED TO TRACK OVER OR JUST NORTH OF NEW 
ORLEANS LOUISIANA WITHIN THE NEXT 12 TO 18 HOURS. HOWEVER...THE 
PRESSURE GRADIENT BETWEEN BERTHA AND THE SURFACE HIGH TO THE 
NORTHEAST MAY INCREASE THE LOW-LEVEL WINDS WELL AWAY FROM THE 
CENTER.  AS SUCH... A TROPICAL STORM WARNING HAS BEEN ISSUED FROM 
PASCAGOULA MISSISSIPPI WEST AND SOUTH TO THE MOUTH OF THE 
MISSISSIPPI RIVER...INCLUDING LAKE BORGNE AND LAKE PONTACHARTRAIN.
 
THE UPPER-LEVEL OUTFLOW PATTERN HAS IMPROVED SIGNIFICANTLY DURING 
THE PAST 9 HOURS. HOWEVER...CONVECTIVE CLOUD TOPS HAVE WARMED SOME 
DURING THE PAST 3 HOURS. DOPPLER RADARS FROM SLIDELL AND MOBILE 
STILL INDICATE DECENT BANDING ON THE NORTH SIDE WITH OCCASIONAL 
DOPPLER VELOCITIES OF 35 TO 50 KT BETWEEN 4000 AND 8000 FT. AS 
BERTHA MOVES CLOSER TO LAND...INCREASING FRICTIONAL CONVERGENCE MAY 
HELP TO FIRE OFF MORE CONVECTION LATER TONIGHT AND ALLOW FOR A 
LITTLE MORE STRENGTHENING BEFORE THE CENTER MOVES INLAND DURING THE 
DAY MONDAY.
 
FORECASTER STEWART
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     04/2330Z 29.4N  89.0W    35 KTS
12HR VT     05/0600Z 30.0N  89.8W    40 KTS...INLAND
24HR VT     05/1800Z 30.5N  91.2W    30 KTS...INLAND AND DISSIPATING
36HR VT     06/0600Z 30.9N  92.8W    25 KTS...INLAND AND DISSIPATING
48HR VT     06/1800Z 31.4N  94.5W    20 KTS...INLAND AND DISSIPATING
72HR VT     07/1800Z...INLAND AND DISSIPATED
  
NNNN