000
AXPZ20 KNHC 121546
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE JUN 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1430 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 08N78W TO 1008 MB LOW PRES NEAR 06N85W TO 
1010 MB LOW PRES NEAR 13N118W TO 06N125W. ITCZ FROM 06N125W TO 
06N140W. SCATTERED TO NUMEROUS MODERATE ISOLATED STRONG WITHIN 
120 NM OF LINE 03N87W TO 5.5N93W TO 09N96W. SIMILAR CONVECTION 
IS WITHIN 90 NM S OF TROUGH FROM 90W TO 92W. 

...DISCUSSION...
SCATTEROMETER COVERAGE AND FEW SHIP OBSERVATIONS REVEAL FRESH 
WINDS OF 20 KT IN THE NORTH-CENTRAL WATERS...PARTICULARLY N OF 
28N BETWEEN 125W AND 135W...WITH WINDS GENERALLY BELOW 20 KT 
ACROSS THE REMAINDER OF THE BASIN. THE PRES GRADIENT ASSOCIATED 
WITH THE SUBTROPICAL RIDGE ANCHORED BY 1030 MB HIGH NEAR 36N140W 
HAS RELAXED THE PAST 24-48 HOURS...ALLOWING N TO NE WINDS W OF 
NORTHERN BAJA TO DIMINISH AS WELL AS NE-E TRADE WINDS NORTH OF 
THE ITCZ AXIS. THE HIGH PRES WILL REMAIN NEARLY STATIONARY 
KEEPING THE FRESH WINDS ACROSS THE N 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. 

GLOBAL MODELS CONTINUE TO INDICATE THE DEVELOPMENT OF A LOW 
PRES AREA A COUPLE OF HUNDRED MILES WEST-SOUTHWEST OF THE COAST 
OF COSTA RICA. IN FACT...A 1008 MB LOW PRES IS CURRENTLY 
ANALYZED ALONG THE MONSOON TROUGH NEAR 06N85W. VISIBLE SATELLITE 
PICTURES SHOW SOME BANDS OF LOW LEVEL CLOUDS SPINNING AROUND THE 
LOW- TO MID-LEVEL CENTER. THE MODELS HAVE COME INTO BETTER 
AGREEMENT WITH REGARD TO THE POTENTIAL TRACK OF THE LOW...WITH 
THE MODEL CONSENSUS SHOWING THE LOW MOVING NW INTO SOUTHEASTERN 
MEXICO NEAR THE GULF OF TEHUANTEPEC LATER THIS WEEK. THE GFS 
MODEL CONTINUES TO FORECAST A STRONG LOW...WHILE THE ECMWF AND 
UKMET MODELS ARE LESS AGGRESSIVE WITH A WEAKER LOW PRES. AT THE 
MOMENT...THIS SYSTEM HAS A LOW CHANCE OF BECOMING A TROPICAL 
CYCLONE DURING THE NEXT 48 HOURS. 

ANOTHER BROAD AREA OF LOW PRES IS NOTED ALONG THE MONSOON TROUGH 
NEAR 11N100W. BOTH...THE GFS AND THE EUROPEAN MODELS ALSO 
SUGGEST THE DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF 
DAYS. A DIFFLUENT PATTERN ALOFT CONTINUES TO SUPPORT CONVECTION 
ALONG THE MONSOON TROUGH E OF 105W...AND NEAR THE POSSIBLE LOW 
PRES AREAS. 

STRONG ELY WINDS OVER WRN CARIBBEAN FUNNELING ACROSS NICARAGUA 
INTO GULF OF PAPAGAYO WILL BRING FRESH E WINDS FROM 10N TO 12N E 
OF 90W THROUGH WED. A COUPLE OF SHIP OBSERVATIONS THIS MORNING 
CONFIRMED THE PRESENCE OF 20-25 KT WINDS ACROSS THE PAPAGAYO 
AREA. ADDITIONAL CYCLONIC VORTICITY PROVIDED FROM THE ENHANCED 
EASTERLY WINDS WILL AID INITIAL SPIN-UP OF ANY LOW PRES AREAS 
THAT MAY DEVELOP SW OF COSTA RICA. 

EXPECT INCREASING WINDS ACROSS THE GULF OF TEHUANTEPEC THIS 
EVENING DUE TO THE A TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER 
INTERIOR MEXICO AND LOWER PRES IN THE BAY OF CAMPECHE. 

$$
GR