Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 191004
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC WED JUN 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 
0945 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
MONSOON TROUGH AXIS EXTENDS FROM 10N85W TO 10N98W TO 1008 MB LOW 
PRES NEAR 10.5N108W TO 10N121W. ITCZ AXIS EXTENDS FROM 10N121W 
TO 08N130W TO 07N140W. SCATTERED STRONG CONVECTION IS WITHIN 120 
NM S OF THE AXIS BETWEEN 85W-90W...AND WITHIN 60 NM S OF THE 
AXIS BETWEEN 90W-92W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION EXISTS FROM 07N TO 09N BETWEEN 93W-102W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS ALSO WITHIN 120 NM N OF 
AXIS BETWEEN 108W AND 111W...AND 120 NM S OF AXIS BETWEEN 112W- 
119W.  

...DISCUSSION...                                                
ALOFT...MAINLY WESTERLY FLOW DOMINATES THE FORECAST REGION N OF 
ABOUT 26N. TO THE SOUTH OF THESE WINDS...BROAD ANTICYCLONE FLOW 
IS NOTED FROM 14N TO 20N AND W OF 112W ASSOCIATED WITH AN 
ANTICYCLONE MOVING E CENTERED AT 22N126W. A RIDGE EXTENDS FROM 
THE ANTICYCLONE NEWD TO CENTRAL AND SOUTHERN BAJA CALIFORNIA 
...AND CONTINUE NE TO NRN MEXICO AND THE CENTRAL CONUS. 
SATELLITE WATER VAPOR IMAGERY DENOTES MODERATE TO STRONG 
SUBSIDENCE ACROSS JUST ABOUT THE ENTIRE AREA N OF 16N...EXCEPT 
IN THE WRN PORTION WHERE UPPER LEVEL MOISTURE IN THE FORM OF 
SCATTERED TO BROKEN CLOUDS AHEAD OF A NE TO SW ORIENTED UPPER 
LEVEL TROUGH NNE OF HAWAII ARE STREAMING NE AND EWD INTO THAT 
PART OF THE AREA. A WEAK UPPER LOW MOVING WSW IS NEAR 16N103W.  
A TROUGH EXTENDS FROM THE LOW NNE TO NEAR TAMPICO MEXICO. A 
SLIGHTLY UPPER DIFFLUENT FLOW PATTERN BETWEEN THE LOW RIDGING TO 
TO ITS SE AND S IS SUSTAINING CONVECTION ALONG AND NEAR THE 
MONSOON TROUGH BETWEEN 108W AND 113W...INCLUDING THE EMBEDDED 
LOW NEAR 10.5N108W AS DESCRIBED ABOVE. ANOTHER WEAK UPPER LEVEL 
LOW IS OVER THE FAR ERN PORTION OF THE AREA NEAR 14N99W WITH A 
SHARP TROUGH SE TO 08N88W. THIS FEATURE IS HELPING TO FURTHER 
ACTIVATE CONVECTION ALREADY TAKING PLACE ALONG THE MONSOON 
TROUGH SEGMENT OVER THE  THE ERN PORTION. TO THE NE OF THIS 
TROUGH...UPPER LEVEL RIDGING COVERS THE AREA TO ENCOMPASS 
CENTRAL AMERICA...AND THE FAR NW CARIBBEAN SEA. ISOLATED 
CLUSTERS OF TSTMS ARE SEEN OVER CENTRAL AMERICA UNDER THE RIDGE. 
ELY UPPER LEVEL FLOW ALONG THE SRN PERIPHERY OF THE RIDGE IS 
ADVECTING MID TO UPPER LEVEL MOISTURE IN THE FORM SCATTERED TO 
BROKEN HIGH CLOUDS OVER THE PORTION OF THE AREA TO THE N OF 05N 
AND E OF ABOUT 88W. 

ELSEWHERE AT THE SURFACE...A NEARLY STATIONARY 1029 MB HIGH PRES 
CENTER IS ANALYZED NW OF THE FORECAST WATERS AT 34N142W WITH A 
RIDGE EXTENDING SEWD THROUGH 32N133W AND TO NEAR 21N121W. AFTER 
ABOUT 24 HRS...THE HIGH CENTER WILL SHIFT SOME TO THE E WITH 
RIDGE PRESSING FURTHER EWD AS WELL. THE PRES GRADIENT TO ITS E 
IN COMBINATION WITH LOWER PRES OVER THE WRN U.S. W COAST IS 
ALLOWING FOR MAINLY FRESH TO STRONG WINDS NEAR THE COAST OF 
CALIFORNIA WITH A PORTION OF THESE WINDS TO GALE FORCE FROM 30N 
TO 36N BETWEEN 119W-123W. NW TO N SWELLS GENERATED BY THESE 
WINDS ARE SPREADING S INTO THE NE PORTION OF THE AREA TO N OF 
28N BETWEEN 117W AND 122W WHERE NW-N WINDS OF 20-25 KT AND SEAS 
OF 8-10 FT ARE CURRENTLY IN OCCURRENCE AS SPOTTED IN THE ASCAT 
PASS FROM VERY NEAR 0500 UTC THIS MORNING. THESE WINDS ARE 
FORECAST TO ABATE AFTER 24 HRS WITH SEAS TO 9 FT IN N TO NE N OF 
26N BETWEEN 117W AND 125W IN 48 HRS.

THE ASCAT PASS FROM 0636 UTC THIS MORNING SHOWED A SWATH OF NE 
MOSTLY 20 KT WINDS WITH EMBEDDED 25 KT WINDS OVER THE FAR WRN 
SECTION OF THE AREA FROM 10N TO 24N W OF 130W. SEAS OF 8-10 FT 
ARE LOCATED FROM 10N TO 20N W OF 135W AS SUGGEST BY ALTIMETER 
DATA FROM TUE AFTERNOON. THESE WINDS ARE FORECAST TO DIMINISH TO 
20 KT IN ABOUT 24 HOURS AS THE GRADIENT RELATED TO THE 
AFOREMENTIONED HIGH AND RIDGE SLACKENS.

GLOBAL MODELS ARE CONSISTENTLY SUGGESTING THAT BROAD LOW PRES MAY 
FORM ACROSS THE ERN PORTION OF THE AREA BEGINNING IN ABOUT 48 
HRS.

ADDITIONAL PULSES OF CROSS EQUATORIAL SW SWELLS WITH LEADING 
EDGE PERIOD OF 19-20 SECONDS ARE PROPAGATING THROUGH THE SOUTH-
CENTRAL WATERS...RAISING SEAS TO 8 FT S OF 03N BETWEEN 126W AND 
137W. THESE SWELLS ARE FORECAST BY WAVEWATCH GUIDANCES TO REACH 
THE COASTLINES OF CENTRAL AMERICA AND MEXICO THROUGH 
TODAY...THEN BE REINFORCED BY YET ANOTHER BATCH OF LONG PERIOD 
SW SWELLS WITH PERIODS OF 16-18 SECONDS. THESE SWELLS COULD LEAD 
TO ROUGH SURF NEAR AND ALONG THE ABOVE COASTLINES. 

$$ 
AGUIRRE