Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 190953
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC SUN MAY 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS W FROM THE COAST OF COLOMBIA AT 
07N77W TO 08N107W WHERE IT LOSES IDENTITY IN THE BROAD CYCLONIC 
CIRCULATION ASSOCIATED WITH THE REMNANT LOW PRESSURE OF FORMER 
TROPICAL CYCLONE ALVIN NOW AT 12N119W. SCATTEROMETER WINDS 
INDICATE AN ITCZ EXTENDS SW FROM NEAR THE REMNANT LOW TO BEYOND 
06N140W. SMALL ISOLATED CLUSTERS OF MODERATE TO STRONG 
CONVECTION IS OBSERVED ALONG THE MONSOON TROUGH...ROUGHLY WITHIN 
90 NM EITHER SIDE OF A LINE FROM 08N83W TO 06N87W TO 07N97W TO 
10N103W.   SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED ALONG THE ITCZ WITHIN 75 NM EITHER SIDE OF LINES FROM 
09N118W TO 08N123W AND FROM 08N129W TO 06N139W. 

THE 1007 MB REMNANTS OF ALVIN ARE CENTERED NEAR 12N115.5W ALONG
A SW-NE ORIENTATED TROUGH WITH NE-E-SE WINDS AT 20-30 KT WITHIN 
240 NM OF THE CENTER OVER THE N SEMICIRCLE PER A RECENT ASCAT-B 
SCATTEROMETER PASS...WITH MAXIMUM SEAS OF 12 FT. A BROAD MIX OF 
SWELL IS MAINTAINING SEAS OF 7-10 FT ELSEWHERE WITHIN 420 NM 
OVER THE W...AND WITHIN 300 NM OVER THE E SEMICIRCLES OF THE 
CENTER. THE LOW IS EXPECTED TO MOVE W AT ABOUT 8 KT TO NEAR 
12N122.5W TONIGHT WITH THE POSSIBILITY OF TROPICAL CYCLONE 
REFORMATION EXISTING FOR ABOUT 24 HOURS BEFORE THE ENVIRONMENT 
BECOMES EVEN MORE HOSTILE. THE LOW SHOULD BEGIN TO TRACK JUST S 
OF DUE W ON MON REACHING NEAR 11.5N125.5W ON MON NIGHT. BY THEN 
WINDS ARE EXPECTED TO DIMINISH TO 15-20 KT WITHIN ABOUT 270 NM 
NW OF CENTER. DISSIPATING REMNANTS OF THE LOW MAY PERSIST AS A 
WEAK CYCLONE EMBEDDED WITHIN THE MONSOON TROUGH WELL INTO THE 
MIDDLE OF THE WEEK BEFORE WEAKENING TO AN OPEN TROUGH.      

A SURFACE RIDGE EXTENDS FROM NW TO SE FROM 32N131W TO 18N109W.
NW WINDS ARE AT 10-15 KT ALONG THE ENTIRE W SHORE OF THE BAJA
CALIFORNIA PENINSULA WITH SEAS OF 4-6 FT. THE GRADIENT WILL
RELAX SOME ON MON SUPPORTING MOSTLY W-NW WINDS AT 10 KT WITH
LITTLE CHANGE THEN EXPECTED THROUGH WED. A SURGE OF NORTHERLY
WINDS WILL MOVE INTO THE N-CENTRAL PACIFIC WATERS N OF 27N 
BETWEEN 118W-125W TONIGHT WITH SEAS MAXING AT 8 FT IN THE
ASSOCIATED N SWELL. A REINFORCING N SURGE AT 20 KT WILL ARRIVE
ALONG 32N ON TUE WITH THESE CONDITIONS SPREADING S ACROSS THE
PACIFIC WATERS N OF 23N BETWEEN 115W-140W ON WED NIGHT...WITH
SEAS BUILDING 8 TO 13 FT IN LONG PERIOD N SWELL. SEAS OF 7-9 
FT ARE EXPECTED TO REACH ALONG THE BAJA PENINSULA TO THE N OF
28N.   

ALOFT...A TROPICAL MOISTURE PLUME...ORIGINATING FROM THE 
CONVECTIVE DEBRIS MOISTURE FROM FORMER TROPICAL CYCLONE ALVIN
AND OTHER CONVECTION ALONG THE MONSOON TROUGH BETWEEN 
115W-125W...CONCENTRATES INTO A 600 NM WIDE PLUME FROM 08N122W
TO 22N106W THEN CONTINUES ACROSS CENTRAL MEXICO AND ACROSS THE
NW GULF OF MEXICO.  

$$
NELSON