000
FZPN03 KNHC 212122
HSFEP2

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC FRI JUN 21 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURE...

THE MAIN FORECAST ISSUE OVER THE NEXT SEVERAL DAYS WILL BE THE 
DEVELOPMENT AND MOVEMENT OF LOW PRES ALONG THE MONSOON TROUGH 
BETWEEN 105W AND 115W. THERE ARE TWO LOW PRES ANALYZED CURRENTLY 
ALONG THE MONSOON TROUGH...ONE AT 11N100W AND ANOTHER AT 
12N117W. BOTH OF THESE LOW PRES AREAS PRESENTED WELL ON ASCAT 
DATA FROM 1646 UTC. THE WESTERNMOST LOW PRES DEVELOPED IN PART 
DUE TO AN UPPER LEVEL CYCLONE THAT HAS SINCE BECOME A SHARPLY 
ELONGATED UPPER TROUGH EXTENDING ALONG 19N BETWEEN 105W AND 
120W. THE EASTERNMOST LOW PRES IS ATTRIBUTED TO THE INTERACTION 
OF A TROPICAL WAVE AND SW FLOW ASSOCIATED WITH THE MONSOON 
TROUGH...AS WELL AS RICH DEEP LAYER MOISTURE. CLUSTERS OF  
CONVECTION ARE PULSING AROUND EACH LOW PRES AREA...BUT MORE 
SUBSTANTIAL COVERAGE OF CONVECTION IS FAVORING THE EASTERNMOST 
LOW. 

MODEL CONSENSUS REMAINS IN GOOD AGREEMENT SHOWING THE CONTINUED 
DEVELOPMENT OF EASTERNMOST LOW PRES AREA. THE GFS REMAINS THE 
OUTLIER INDICATING THAT BOTH LOW PRES AREAS WILL CONTINUE TO 
DEVELOP...WHEREAS ALL OTHER OPERATIONAL AND ENSEMBLE MODELS 
INDICATE THE EASTERMOST DEVELOPING AT THE EXPENSE OF THE WESTERN 
LOW. THE OFFICIAL FORECAST FOLLOWS THE MORE BALANCED CONSENSUS 
APPROACH AND GRADUALLY MERGES THE WESTERNMOST LOW INTO THE 
EASTERN LOW THROUGH MON. THIS SITUATION WILL CONTINUE TO BE 
MONITORED BY THE NATIONAL HURRICANE CENTER...AND THERE IS A 
MEDIUM CHANCE OF TROPICAL CYCLONE FORMATION THROUGH 48 HOURS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
MONSOON TROUGH AXIS EXTENDS FROM 09N85W TO 1008 MB LOW PRES NEAR 
11N100W TO 14N110W TO 1009 MB LOW PRES NEAR 12N117W TO 08N130W. 
ITCZ AXIS CONTINUES FROM 08N130W TO 08N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 45 NM S OF MONSOON 
TROUGH AXIS BETWEEN 90W AND 92W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS NOTED FROM 09N TO 15N BETWEEN 100W AND 105W.

...DISCUSSION... 

ELSEWHERE E OF 130W...MODERATE TO FRESH SW FLOW CONTINUES CROSS 
THE EQUATOR AND CONVERGE INTO THE MONSOON TROUGH. ALTIMETER 
PASSES OVER THE PAST SEVERAL HOURS SHOWED SEAS TO BE GENERALLY 
SIX TO SEVEN FEET. GLOBAL WAVE GUIDANCE INDICATES AN AREA OF SW 
SWELL WITH SEAS TO 8 FT WILL PUSH ACROSS THE EQUATOR 
SUN...REACHING AS FAR N AS 10N BETWEEN 100W AND 130W BY MIDDAY 
MON...LIKELY MIXING WITH FRESH SWELL GENERATED BY THE DEVELOPING 
LOW PRES IN THE AREA BETWEEN 100W AND 110W. 

FARTHER NORTH...STATIONARY 1029 MB HIGH PRES IS CENTERED NEAR 
32N140W. FRESH NW TO N WINDS PERSIST N OF 27N BETWEEN 118W AND 
122W WITH SEAS TO 8 FT. WINDS AND SEAS WILL DIMINISH THROUGH 
TONIGHT AS THE HIGH PRES WEAKENS AHEAD OF A SHORT WAVE TROUGH 
DIGGING EASTWARD ACROSS THE NE PACIFIC. THE FRESH WINDS AND SEAS 
TO 8 FT WILL CROSS S OF 30N IN THE SAME AREA SUN AS THE RIDGE 
BUILDS ON THE WEST SIDE OF THE EXITING SHORT WAVE TROUGH. 
 
 
$$ 
CHRISTENSEN