000
AXPZ20 KNHC 041004
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUL 04 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
000 UTC.

...SPECIAL FEATURES...
TROPICAL DEPRESSION BORIS AT 17.1N 130.4W...OR 1210 NM WSW OF 
CABO SAN LUCAS MEXICO...AT 04/000 UTC MOVING WSW AT 6 KT. 
MAXIMUM SUSTAINED WIND SPEED DIMINISHED TO 30 GUSTING 40 KT. 
ESTIMATED MINIMUM CENTRAL PRES 1003 MB. NO MORE ADVISORIES ARE 
BEING ISSUED ON BORIS BY THE NHC.  BORIS HAS NOW LOST ALL ITS 
DEEP CONVECTION WITH ONLY SCATTERED SHOWERS WITHIN 240 NM N AND 
NE QUADRANTS.  THE SYSTEM IS EXPECTED TO WEAKEN TO A REMNANT LOW 
WITHIN THE NEXT 12 HOURS AS IT MOVES OVER COOL WATERS AND INTO 
THE STABLE AIR MASS TO ITS W.

TROPICAL DEPRESSION DOUGLAS AT 21.0N 111.2W...OR 135 NM SSW OF 
CABO SAN LUCAS MEXICO...AT 04/000 UTC MOVING WNW AT 8 KT. 
MAXIMUM SUSTAINED WIND SPEED HAS DIMINISHED TO 25 GUSTING 35 KT. 
ESTIMATED MINIMUM CENTRAL PRES 1004 MB.  NO MORE ADVISORIES ARE 
BEING ISSUED ON DOUGLAS BY THE NHC.  DOUGLAS HAS BECOME SWIRL 
OF LOW CLOUDS WITH ONLY SCATTERED SHOWERS STILL WITHIN 120 NM S 
SEMICIRCLE NEAR SOCORRO ISLAND.  WITHOUT DEEP CONVECTION SYSTEM 
EXPECTED TO DEGENERATE INTO REMNANT LOW WITHIN NEXT 12 HOURS. 

LOW PRES 1008 MB AT 11N95W...OR ABOUT 250 NM S OF PUERTO ANGEL 
MEXICO...MOVING WNW AT 5 KT.  LOW-LEVEL CENTER HAS BEEN 
DIFFICULT TO LOCATE OVER PAST 12 HRS OR SO...AND IT IS POSSIBLE 
THAT IT NEVER WAS VERY WELL-DEFINED AND HAS BEEN REFORMING.  
DEEP CONVECTION RATHER SPARSE...WITH ONE BAND DISPLACED ABOUT 
150 NM NE OF THE CENTER AND ANOTHER AREA WELL S NEAR A 
CONVERGENCE AXIS ALONG 07N. SCATTERED MODERATE/STRONG CONVECTION 
FROM 12N-15N BETWEEN 91W-96W. WHILE THE LIKELIHOOD HAS DECREASED 
SINCE YESTERDAY...TROPICAL CYCLONE DEVELOPMENT IS STILL POSSIBLE 
WITHIN THE NEXT 48 HOURS AS THE SYSTEM MOVES SLOWLY NW OFF THE 
SOUTHERN COAST OF MEXICO.

...TROPICAL WAVES...

TROPICAL WAVE ACROSS PANAMA ALONG 81W N OF 02N MOVING W 10-15 
KT.  WAVE NOT VERY WELL-DEFINED BUT NEAR CONVECTION OVER SW 
CARIBBEAN.  SCATTERED MODERATE N OF 04N ACROSS PANAMA E OF 83W.

...ITCZ...
ITCZ AXIS ALONG 08N78W TO 11N88W TO 09N97W TO 13N120W TO 
05N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 
90 NM OF AXIS E OF 96W.  SCATTERED MODERATE CONVECTION WITHIN 
120 NM S OF AXIS FROM 100W-110W.
 
...DISCUSSION...
UPPER LEVELS...
SHARP UPPER LEVEL TROUGH FROM 32N130W TO 22N140W DIGGING S WHILE 
MOVING E WILL ENCOUNTER STEADFAST BROAD RIDGE CENTERED AT 
23N116W AS OBSTACLE TO ITS PRESENT TRACK.  TROUGH ALSO BRINGS 
PLENTY OF MOISTURE RIDING ON 80 KT JET CORE INTO AN OTHERWISE 
DRY AIR MASS W OF 110W.  RIDGE SHOULD HOLD ITS POSITION OR MOVE 
SLIGHTLY E OVER BAJA CALIFORNIA AS TROUGH SHIFTS TRACK NE AND 
FLATTENS RIDGE CREST N OF 30N.  STRONG 50 KT SW WINDS...SAME 
ONES THAT RIPPED BORIS APART...NOW TAKING THE CYCLONE MOISTURE 
DEBRIS N-NE OUT OF BASIN.  

MINOR WEAKNESS IN RIDGE ALLOWS SURFACE THERMAL LOW PRES ALONG 
CENTRAL MEXICO WHILE RIDGE EXTEND SE TO WEAK ANTICYCLONIC GYRE 
AT 21N101W.  GYRE CAUSING STRONG E FLOW OVER WEAK LOW PRES NEAR 
11N95W SHEARING IT AND CURTAILING ANY REAL CHANCE OF DEVELOPMENT
AT LEAST FOR NEXT 48 HR.  LASTLY...HEALTHY ANTICYCLONE AT 15N81W 
IN WRN CARIBBEAN ENHANCING DIFFLUENT FLOW ABOVE TRPCL WAVE ALONG 
81W AND HELPING DEEP CONVECTION AS WAVE IS ABOUT TO ENTER E PAC. 

AT THE SURFACE...
REMNANTS OF TROPICAL DEPRESSION DOUGLAS 20N112W REMAINS OVER 
COLD WATERS WITH LITTLE OR NO CHANCE OF MAKING A COMEBACK.  
TROPICAL DEPRESSION BORIS NOW AT 17N131W ABOUT TO BE GIVEN LAST 
RITES AS CONVECTION HAS DESERTED CENTER AND COLD SST TAKE HOLD  
OF ITS CONVECTION. 

HIGH PRES CENTER 1019 MB AT 28N134W HOLDS ON IN SPITE OF 
EX-CYCLONES DENTING SE CORNER OF RIDGE.  RIDGE FORCED E BY WEAK 
TROUGH N OF AREA HAS INCREASED N WIND OFF CALIFORNIA COAST AND 
SOME 9 FT SWELLS THAT ENTER E PAC BUT SUBSIDE WITHIN 48 HR.

$$
WALLY BARNES