000
AXPZ20 KNHC 130220
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED JUN 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0145 UTC.

...SPECIAL FEATURES...

SATELLITE IMAGERY THIS EVENING CONTINUES TO SHOW MODERATE TO 
STRONG CONVECTION OCCURRING ACROSS THE FAR EPAC BETWEEN 87W AND 
93W...AND BEGINNING TO ALIGN IN BANDS. A BROAD MID LEVEL 
CYCLONIC CIRCULATION IS SUGGESTED NEAR 08N87W...A BIT TO THE SE 
OF THE ESTIMATED SURFACE LOW AT 08N89.5W. SEVERAL SHIP REPORTS 
ACROSS THE AREA AT 0000 UTC SUGGESTED PRESSURES ARE LOWERING AND 
THE LOW IS ESTIMATED AT 1005 MB. GAP WIND FLOW ACCELERATING 
DOWNSTREAM FROM THE GULF OF PAPAGAYO IS PRODUCING AN ELONGATED 
PLUME OF NE TO E WINDS 20 TO 25 KT ACROSS THE N PERIPHERY OF 
THIS AREA...WHICH WILL AID IN FURTHER DEVELOPMENT OF THIS LOW.  
THIS CIRCULATION REMAINS EMBEDDED NEAR THE EASTERN END OF AN 
ELONGATED LOW TO MID LEVEL TROUGH EXTENDING BETWEEN 80W AND 
120W...WHERE ABUNDANT TROPICAL MOISTURE PERSISTS. ATMOSPHERIC 
AND OCEANIC CONDITIONS ARE FAVORABLE FOR THIS SYSTEM TO BECOME 
BETTER ORGANIZED AND IT HAS A MODERATE CHANGE OF DEVELOPING INTO 
A TROPICAL CYCLONE IN THE NEXT 24 TO 48 HOURS...AS IT SHIFTS NW. 
GLOBAL MODELS ARE RATHER AGGRESSIVE WITH THE DEVELOPMENT OF THIS 
SYSTEM... SUGGESTING IS COULD DEEPEN QUICKLY. INTERESTS ALONG 
THE PACIFIC COASTS OF GUATEMALA AND SOUTHEAST MEXICO SHOULD 
MONITOR THIS SYSTEM. 

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

MONSOON TROUGH EXTENDS FROM LOW PRES 1003 MB OVER COLOMBIA NEAR 
FROM 06N74W TO 09N83W TO LOW PRES 1005 MB NEAR 08N89.5W TO 
12N100W TO LOW PRES 1008 MB NEAR 13N114W TO 06N124W...WHERE IT 
TRANSITIONS TO ITCZ...CONTINUING ON TO 07N135W TO BEYOND 
06N140W. SCATTERED MODERATE TO STRONG CONVECTION N OF 06N E OF 
80W...AND WITHIN 180 NM N AND 360 NM S OF TROUGH BETWEEN 93W AND 
118W.

...DISCUSSION...

LATE AFTERNOON SCATTEROMETER COVERAGE AND FEW SHIP OBSERVATIONS 
CONTINUE TO SHOW FRESH WINDS OF 20 KT IN THE NORTH-CENTRAL 
WATERS...PARTICULARLY N OF 27.5N BETWEEN 122W AND 137W...WITH 
WINDS GENERALLY BELOW 20 KT ACROSS THE REMAINDER OF THE BASIN W 
OF 110W. THE PRES GRADIENT ASSOCIATED WITH THE SUBTROPICAL RIDGE 
ANCHORED BY 1030 MB HIGH NEAR 37N139W HAS RELAXED THE PAST 24-48 
HOURS...ALLOWING N TO NE WINDS W OF NORTHERN BAJA TO 
DIMINISH...WHILE THE NE-E TRADE WINDS NORTH OF THE ITCZ AXIS 
HAVE ALSO FALLEN BELOW 20 KT. THE HIGH PRES WILL REMAIN NEARLY 
STATIONARY KEEPING THE FRESH WINDS ACROSS THE N CENTRAL 
WATERS...MAINLY N OF 27N...OVER THE NEXT COUPLE OF DAYS. 
INCREASING WINDS TO LIKELY GALE FORCE N OF THE AREA AND NEAR 
SOUTHERN CALIFORNIA WILL BRING ADDITIONAL PULSES OF NW 
SWELL...RAISING SEAS TO ABOUT 10 FT NEAR 30N120W BY THU. 

E OF 120W...THE EPAC MONSOON TROUGH HAS BECOME WELL ESTABLISHED 
AND NOW EXTENDS DEEPER INTO THE LOWER TROPOSPHERE...FROM NW 
COLOMBIA/PANAMA TO A BROAD AND WEAKENING LOW TO MID LEVEL LOW 
NEAR 13N114W. IN ADDITION TO THE SPECIAL FEATURE ABOVE...AND THE 
LOW ALONG 114W...TWO TO THREE OTHER LOW LEVEL CYCLONIC 
CIRCULATIONS ARE NOTED ALONG THE TROUGH...BUT ARE LIKELY 
TRANSIENT AND WILL LIKELY MERGE OR REFORM WITHIN THE TROUGH IN 
THE NEXT FEW DAYS. AFTERNOON SCATTEROMETER PASSES DEPICTED 
CLASSIC MONSOONAL WINDS S OF THE TROUGH...WITH AREAS OF SW TO W 
WINDS NEAR 20 KT...FUELING ACTIVE CONVECTION... NOW OCCURRING 
FROM 82W TO 118W. TPW ANIMATIONS SHOW ABUNDANT TROPICAL MOISTURE 
CONVERGING ON BOTH SIDES OF THE TROUGH MAKING FOR A VERY 
UNSTABLE ENVIRONMENT. VERY LIGHT VERTICAL WIND SHEAR ACROSS THE 
AREA IS ALLOWING FOR THE CLUSTERS OF CONVECTION TO FURTHER 
DIVERT THE UPPER LEVEL WINDS ACROSS THIS REGION...PROVIDING AN 
ENVIRONMENT FAVORABLE FOR ACTIVE AND SUSTAINED DEEP CONVECTION 
AND POTENTIAL TROPICAL CYCLOGENESIS.    

NORTHERLY WINDS AROUND 20 KT ARE CURRENTLY BLOWING ACROSS THE 
GULF OF TEHUANTEPEC AND A SHORT DISTANCE SW THIS EVENING DUE TO 
THE A TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER INTERIOR MEXICO 
AND LOWER PRES IN THE BAY OF CAMPECHE. THESE FRESH N WINDS ARE 
EXPECTED TO CONTINUE THROUGH WEDNESDAY EVENING.  

$$
STRIPLING