000
AXPZ20 KNHC 261559
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 UTC WED JUN 26 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...SPECIAL FEATURES...

EARLIER HURRICANE COSME HAS BEEN DOWNGRADED TO A TROPICAL STORM 
AT 1500 UTC...WITH A POSITION OF 19.1N 115.6W AND PRESSURE OF 
988 MB MOVING WNW OR 295 DEGREES AT 12 KT. MAXIMUM SUSTAINED 
WINDS ARE 60 KT WITH GUSTS TO 75 KT. LATEST SATELLITE IMAGERY 
SHOWS THAT THE CYCLONE IS UNDERGOING WEAKENING AS DEEP 
CONVECTION SEEN EARLIER IN ITS OUTER FRINGES HAS DIMINISHED. 
PRESENTLY DEEP CONVECTION IS OBSERVED AS OF THE NUMEROUS STRONG 
TYPE WITHIN 90 NM OF THE CENTER IN THE SW AND ALSO 75 NM OF THE 
CENTER IN THE NW QUADRANTS. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS NOTED ELSEWHERE WITHIN 60 NM E AND 120 NM W 
SEMICIRCLES OF THE CENTER. COSME IS FORECAST TO CONTINUE TO 
FURTHER WEAKEN THROUGH TODAY REACHING POST-TROPICAL REMNANT LOW 
STATUS IN ABOUT 36-48 HOURS. SEE THE LATEST FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP3/WTNT23 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH AXIS EXTENDS W FROM NW COLOMBIA TO 08N96W TO 
10N102W...THEN RESUMES AT 12N121W TO 08N140W. SCATTERED MODERATE 
TO STRONG CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 93W-
104W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS FROM 
08N TO 12N BETWEEN 104W-111W.

...DISCUSSION... 

A SMALL UPPER CYCLONE NEAR 30N127W IS LIFTING NEWD WITH AN UPPER 
TROUGH EXTENDING SW INTO ANOTHER UPPER CYCLONE ALSO LIFTING NEWD 
W OF THE AREA NEAR 21N142W. SCATTERED THIN UPPER LEVEL CLOUDS 
ARE SEEN WITHIN OVER THE FAR NW CORNER OF THE AREA. AT THE 
SURFACE...A WEAKENING COLD FRONT IS ANALYZED FROM 32N133W TO SW 
OF THE AREA AT 27N140W. THE FRONT IS FORECAST TO DISSIPATE BY 
THIS EVENING. SEAS OF 8 FT N AND NW OF THE FRONT WILL SHIFT NE 
OF THE AREA ON THU MORNING.  

AN UPPER LEVEL ANTICYCLONE OVER THE SW U.S. EXTENDS ITS SW 
PERIPHERY ACROSS THE GULF OF CALIFORNIA AND BAJA PENINSULA AREA
...WITH ITS ENVELOPE OF ANTICYCLONIC FLOW DOMINATING THE UPPER 
LEVELS BETWEEN 98W-112W PROVIDING THE UPPER DIFFLUENCE OVER 
TROPICAL STORM COSME...AND FOR MONSOON TROUGH CONVECTION AS 
DESCRIBED ABOVE. THIS CONVECTION CONTINUES TO CONTRIBUTE TO 
EXTREMELY DENSE UPPER MOISTURE TRAPPED WITHIN THE ANTICYCLONIC 
ENVELOPE. THIS MID/UPPER RIDGE WILL PROVIDE THE STEERING FOR 
TROPICAL CYCLONE COSME AS IT CONTINUES TO WEAKEN OVER THE NEXT 
COUPLE OF DAYS. 

ELSEWHERE AT THE SURFACE...A WEAK 1018 MB HIGH IS ANALYZED AT 
26N134W WITH A RIDGE STRETCHING ENE ACROSS THE AFOREMENTIONED 
COLD FRONT TO 30N122W. THE HIGH IS FORECAST TO WEAKEN SLIGHTLY 
AS IT SHIFTS N THROUGH THE NEXT 24-36 HRS. GLOBAL MODELS SUGGEST 
THAT BROAD LOW PRES WILL MATERIALIZE IN ALONG AND NEAR THE 
MONSOON TROUGH BETWEEN 95W-107W OVER THE NEXT 48 HRS AS WAVE 
ENERGY FROM THE CARIBBEAN SEA ENTERS THAT PORTION OF THE AREA.
 
CROSS EQUATORIAL SOUTHERLY SWELLS WILL CONTINUE TO PROPAGATE N 
ACROSS THE DISCUSSION AREA BETWEEN 99W-130W AND ALSO BE 
REINFORCED BY SWELL GENERATED BY TROPICAL CYCLONE COSME. THESE 
SOUTHERLY SWELLS ARE REACHING THE PACIFIC COAST OF MEXICO 
ROUGHLY FROM 17N-25N...INCLUDING THE GULF OF CALIFORNIA S OF 
25N. THESE SWELLS WILL CONTINUE PROPAGATE N ALONG THE WESTERN 
SHORE OF THE BAJA PENINSULA REACHING ALONG 30N LATE TONIGHT. THE 
SWELL WILL SUBSIDE TO LESS THAN 8 FT JUST S OF THE TIP OF BAJA 
CALIFORNIA ON THU EVENING.
 
$$ 
AGUIRRE