000
AXPZ20 KNHC 130933
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAY 13 2012

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 
0845 UTC.

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

MONSOON TROUGH EXTENDS FROM 10N85W TO 08N100W TO 1009 MB LOW AT 
10N106W TO 1010 MB LOW AT 08N116W THEN THE ITCZ CONTINUES TO 
04N130W TO 02N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 
180 NM S OF TROUGH BETWEEN 98W AND 102W. SIMILAR CONVECTION IS 
WITHIN 70 NM N OF ITCZ AXIS BETWEEN 128W AND 130W.   

...DISCUSSION...

ALOFT...A LARGE AND WELL-DEFINED MIDDLE/UPPER LEVEL CYCLONIC 
CIRCULATION IS POSITIONED AT 35N131W AND IS MOVING AWAY FROM THE 
FORECAST AREA. A BROAD RIDGE DOMINATES MOST OF THE N WATERS. 
MODERATE SOUTHWESTERLY WINDS ARE TRANSPORTING MID/UPPER LEVEL 
MOISTURE FROM THE TROPICS ALL THE WAY NE ALONG 21N130W TO 
28N120W INTO NORTHERN BAJA CALIFORNIA AND NW MEXICO. WATER VAPOR 
IMAGERY INDICATES STRONG SUBSIDENCE FROM 15N TO 26N E OF 116W 
INCLUDING THE COAST OF MEXICO. A SECOND BROAD RIDGE ANCHORED ON 
AN UPPER ANTICYCLONE OVER NORTHERN CENTRAL AMERICA COVERS THE 
WATERS E OF 105W. UPPER DIFFLUENCE ASSOCIATED WITH THIS FEATURE 
IS HELPING TO SUPPORT THE CONVECTIVE ACTIVITY PREVIOUSLY 
DESCRIBED IN THE ITCZ/MONSOON TROUGH SECTION. IN ADDITION...A 
COUPLE OF CLUSTERS WITH MODERATE TO STRONG CONVECTION ARE NOTED 
IN THE GULF PANAMA AND IN THE GULF OF TEHUANTEPEC. WINDS AND 
SEAS WILL BE HIGHER NEAR THE TSTMS.

AT LOWER LEVELS...A PAIR OF LOW PRES SYSTEMS ARE ALONG THE 
MONSOON TROUGH. THE EASTERNMOST IS LOCATED NEAR 10N106W. 
CONVECTION HAS DIMINISHED IN ASSOCIATION WITH THIS SYSTEM DURING 
THE PAST FEW HOURS. MOST OF THE SHOWER AND TSTMS ACTIVITY 
REMAINS TO THE E OF THE LOW LEVEL CENTER. GLOBAL MODELS ARE NOW 
IN PRETTY GOOD AGREEMENT SHOWING SOME POTENTIAL FOR TROPICAL 
DEVELOPMENT AS THIS LOW PRES DRIFTS NW DURING THE NEXT 48 HOURS. 
FOR NOW...THE FORECAST INDICATES WINDS OF 20-25 KT WITHIN 90-120 
NM OF CENTER. THE WESTERNMOST LOW IS SITUATED NEAR 08N116W. 
SCATTERED MODERATE CONVECTION IS NOTED WITHIN 180 NM NW QUADRANT 
OF LOW CENTER. THIS SYSTEM WILL REMAIN WEAK AND WILL GRADUALLY 
DISSIPATE IN ABOUT 48-72 HOURS.  

ELSEWHERE AT THE LOWER LEVELS...
A WEAK 1022 MB HIGH PRES REMAINS OVER THE N-CENTRAL WATERS NEAR 
27N128W. PRES GRADIENT BETWEEN THIS HIGH...FORECAST TO REMAIN 
NEARLY STATIONARY...AND A TROUGH OVER NW MEXICO IS RESULTING IN 
NW WINDS 20 KT JUST W OF THE COAST OF BAJA CALIFORNIA N OF 24N. 
THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH 48 HOURS 
PARTICULARLY N OF 26N. DUE TO THE PRESENCE OF THIS HIGH PRES 
OVER THE N WATERS...NE TRADEWINDS OF 20 KT ARE CONFINED TO A 
RELATIVELY SMALL AREA FROM 07N TO 12N W OF 130W. SCATTEROMETER 
DATA PROVIDED OBSERVATIONS OF THESE WIND SPEEDS. 

A TROUGH OVER THE BAY OF CAMPECHE WILL INDUCE A GAP WIND EVENT 
ACROSS THE CHIVELA PASS INTO GULF OF TEHUANTEPEC THIS MORNING.  
EXPECT WINDS OF 20 TO 25 KT AND BUILDING SEAS TO AROUND 10 FT TO 
LIKELY PERSIST THROUGH TUE. 

WINDS ARE ALSO FORECAST TO INCREASE ACROSS THE GULF OF PAPAGAYO 
EARLY THIS MORNING AS FRESH TO STRONG TRADE WIND FLOW IN THE SW 
CARIBBEAN FUNNELS THROUGH THE GAP. IN FACT...THE 0330 UTC ASCAT 
PASS IS ALREADY SHOWING E WINDS OF 20 KT ACROSS THE AREA. 

$$
GR