Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 240219 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC THU MAY 23 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 
2145 UTC.

...SPECIAL FEATURE...

A 1009 MB LOW IS EMBEDDED WITHIN THE MONSOON TROUGH NEAR 10N104W 
MOVING W 09 KT. LATEST VISIBLE IMAGERY SHOWS A SMALL CIRCULATION 
CENTER 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 
CONVECTION IS WITHIN 120 NM OF THE LOW IN THE NE 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 CENTRAL COAST RICA TO 12N95W TO 
LOW PRES NEAR 11N104W 1010 MB TO 08N117W...WHERE IT TRANSITIONS 
TO ITCZ AND CONTINUES TO 09N126W TO 10N132W TO BEYOND 09N140W. 
SCATTERED MODERATE TO STRONG CONVECTION IS FROM 06N TO 09N 
BETWEEN 94W-99W...AND WITHIN 180 NM N OF THE AXIS BETWEEN 131W-
136W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 
180 NM S OF THE AXIS BETWEEN 82W-89W...AND ALSO BETWEEN 114W-
118W. 

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 12N127W. 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 1032 MB HIGH CENTER IS WELL N OF THE AREA AT 
40N143W...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 36 HOURS. AS IT PASSES 
DIRECTLY S OF THE EPAC HIGH...WINDS MAY INCREASE SLIGHTLY TO 20-
25 KT.

E OF 110W...MODERATE MONSOONAL FLOW DOMINATES THE TROPICS AND IS 
PRODUCING CONVERGENCE OF ABUNDANT TROPICAL MOISTURE INVOF 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. EXPECTED 
SW SWELL AND ADDITIONAL PULSES TO DOMINATE THE AREA WATERS 
THROUGH THE WEEKEND...AND BRING STRONG AND DANGEROUS SURF ACROSS 
NEAR THOSE COASTS.

$$
AGUIRRE