Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 240258
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC FRI MAY 24 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0245 UTC.

...SPECIAL FEATURE...

A 1010 MB LOW IS EMBEDDED WITHIN THE MONSOON TROUGH NEAR 09N104W 
MOVING WNW 10 KT. LATEST VISIBLE IMAGERY SHOWS A SMALL MOSTLY 
MID-LEVEL CIRCULATION ASSOCIATED WITH THE LOW. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE LOW 
IN THE SE AND S QUADRANTS...AND ALSO WITHIN 45 NM OF 09N105W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM 
OF THE LOW IN THE SE QUADRANT...AND ALSO WITHIN 120 NM OF THE LOW 
IN THE NW QUADRANT. THE LOW IS UNDERNEATH UPPER LEVEL 
RIDGING...AND OVER RATHER WARM SEA SURFACE TEMPERATURE. THESE 
INGREDIENTS MAY ALLOW OR THE LOW TO GRADUALLY INTENSIFY OVER THE 
NEXT 48 HOURS...WITH A MEDIUM PROBABILITY OF TROPICAL CYCLONE 
FORMATION.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM SRN COSTA RICA TO 09N90W TO 
10N98W TO LOW PRES NEAR 09N104W 1010 MB TO 08N114W. ITCZ BEGINS 
AT 07N120W TO 10N134W. SCATTERED MODERATE TO STRONG WITHIN 150 
NM S OF THE AXIS BETWEEN 82W AND 89W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE 
AXIS BETWEEN 94W AND 100W...WITHIN 120 NM N OF THE AXIS BETWEEN 
113W AND 117W...BETWEEN 128W AND 131W...AND FROM 10N TO 12N 
BETWEEN 132W AND 137W. 

A GENERALLY RIDGE-TROUGH-RIDGE UPPER LEVEL PATTERN IS ANALYZED 
ACROSS THE DISCUSSION AREA. THE FIRST RIDGE IS E OF 108W...WITH 
THE TROUGH FROM 32N118W TO 15N113W. THE SECOND RIDGE IS BROAD IN 
NATURE...AND COVERS THE AREA W OF THE TROUGH WITH THE 
ANTICYCLONIC CIRCULATION AT 12N126W. THESE RIDGES CONTINUE TO 
VENTILATE DEEP TROPICAL CONVECTION ALONG AND NEAR THE MONSOON 
TROF AND ITCZ DESCRIBED ABOVE. A SHORTWAVE TROUGH HAS MOVED OVER 
THE WESTERN RIDGE AND IS DIVING INTO THE BACK SIDE OF THE 
TROUGH. THE FORWARD PROGRESS OF THE MEAN UPPER TROUGH IS 
FORECAST TO END TONIGHT WHILE THE TROUGH SHARPENS OVER THE 
WEEKEND...AS THE TWO UPPER RIDGES AMPLIFY.

AT THE SURFACE...A 1033 MB HIGH CENTER IS WELL N OF THE AREA AT 
39N142W...WITH A RIDGE SEWD TO 27N128W TO NEAR 21N118W. HIGH 
PRES COVERS THE AREA N OF 16N W OF 117W. THE TIGHT PRES GRADIENT 
BETWEEN THE RIDGE AND LOW PRES OVER THE WRN U.S. CONTINUES TO 
RESULT IN STRONG NW-N WINDS JUST N OF THE NE PORTION OF THE 
AREA. NW-N WINDS OF 20-25 KT CONTINUE TO SEEP S INTO THE AREA TO 
THE N OF 29N AND BETWEEN 119W-123W WITH SEAS TO 13 FT.

THE REMNANTS OF ALVIN WERE LOCATED ACROSS SW PORTIONS... 
PROPAGATING WWD AS A LARGE AMPLITUDE WAVE ALONG THE ITCZ AT 
133W. A MODEST REGION OF FRESH NE WINDS AROUND 20 KT CONTINUE N 
OF THIS WAVE AND ARE PRODUCING SEAS 8-9 FT. THIS WAVE WILL 
CONTINUE W AND EXIT THE AREA IN THE NEXT 30 HOURS. AS IT PASSES 
DIRECTLY S OF THE EPAC HIGH...WINDS MAY INCREASE SLIGHTLY TO 20-
25 KT.

MODERATE MONSOONAL FLOW DOMINATES THE TROPICS AND IS PRODUCING 
CONVERGENCE OF ABUNDANT TROPICAL MOISTURE ALONG AND NEAR THE 
MONSOON TROUGH. STRENGTHENING HIGH PRES ACROSS THE SW N ATLANTIC 
IS EXPECTED TO ENHANCE THE TRADE WINDS ACROSS THE CENTRAL AND W 
CARIBBEAN BY THE EARLY PART OF THE UPCOMING WEEK...WHICH WILL 
INDUCE GAP WIND FLOW ACROSS CENTRAL AMERICA AND INTO THE EPAC.

LONG PERIOD CROSS HEMISPHERIC SW SWELL AT 17-19 SECONDS IS 
MOVING THROUGH THE AREA WATERS THIS MORNING AND HAVE BEGUN TO 
INCREASE ALONG THE CENTRAL AMERICAN AND MEXICAN COASTS. EXPECT 
SW SWELLS AND ADDITIONAL PULSES TO DOMINATE THE AREA WATERS 
THROUGH THE WEEKEND...AND BRING STRONG AND DANGEROUS SURF NEAR 
THOSE COASTS.

$$
AGUIRRE