000
AXPZ20 KNHC 271533
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JUL 27 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 
1515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 16N116W TO 22N114W MOVING W-NW AT 15 
KT. THE WAVE CONTINUES TO DRIFT W-NW AS IT ROUNDS A MIDDLE TO 
UPPER LEVEL RIDGE CENTERED OVER NORTHERN MEXICO AND SOUTHERN NEW 
MEXICO NEAR 32N107W. IT IS EXPECTED TO STRUGGLE PRODUCING 
SIGNIFICANT CONVECTION AS WIND SHEAR INCREASES TO THE NW OF THE 
WAVE. WIDELY SCATTERED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF 
THE WAVE AXIS.

TROPICAL WAVE EXTENDS FROM 11N133W TO 16N130W MOVING W AT 10 KT. 
A WEAK 1009 MB LOW IS CENTERED ALONG THE WAVE AXIS NEAR 11N133W 
AND CONTINUES TO LACK AND SIGNIFICANT CONVECTION TO DUE 
INCREASING SOUTHWESTERLY WINDS ALOFT TO THE NW OF THE WAVE AXIS. 
AN EARLIER ASCAT PASS AROUND 27/0602 UTC SHOWED 20 TO 25 KT 
WINDS FROM 11N TO 17N MOSTLY WEST OF THE AXIS WITH SEAS TO 9 FT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH IS ALONG 07N78W TO 10N93W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 10N93W TO 10N106W TO 12N115W 
TO 06N126W TO 1009 MB LOW PRES NEAR 11N133W TO 08N140W. NUMEROUS 
MODERATE AND SCATTERED STRONG CONVECTION IS FROM 04N TO 08N 
BETWEEN 77W AND 82W. SCATTERED MODERATE CONVECTION IS FROM 05N 
TO 12N BETWEEN 114W AND 126W.

...DISCUSSION...
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION CENTERED NEAR 16N125W THAT EXTENDS A RIDGE AXIS 
NORTH-NORTHWESTWARD TO BEYOND 32N137W. TO THE EAST OF THIS RIDGE 
AXIS...A WEAK MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH EXTENDS AN 
AXIS ALONG 125W THAT DIPS SOUTHWARD TO A BASE NEAR 20N...HOWEVER 
DRY AIR DOMINATES OVER THE MUCH OF THE NORTHERN FORECAST WATERS 
N OF 18N W OF 116W. OVERALL STABILITY REMAINS IN PLACE ACROSS 
THIS REGION AND IS FURTHER ENHANCED DUE TO THE SUBTROPICAL HIGH 
AND ASSOCIATED RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NW OF 
THE DISCUSSION AREA NEAR 37N147W. WINDS ON THE SOUTHEASTERN 
PERIPHERY OF THE HIGH ARE GENERALLY IN THE 5 TO 15 KT RANGE WITH 
SEAS BELOW 8 FT.

THE REMAINDER OF THE DISCUSSION AREA S OF 15N BETWEEN 95W AND 
120W IS UNDER THE INFLUENCE OF PRIMARILY EASTERLY WINDS ALOFT. 
ASIDE FROM A FEW SCATTERED MODERATE CONVECTIVE CELLS ALONG AND 
SOUTH OF THE ITCZ...IT CONTINUES TO BE RATHER TRANQUIL SPEAKING 
IN TERMS OF THE ATMOSPHERE. HOWEVER...IT APPEARS THAT RESIDUAL 
ENERGY ASSOCIATED WITH THE TROPICAL WAVE ALONG 115W REMAINS 
SOUTH OF 13N IN THE VICINITY OF 118W AND ALONG WITH LOW-LEVEL 
CONVERGENCE GENERATED BY THE ITCZ IS RESULTING IN SCATTERED 
MODERATE CONVECTION FROM 05N TO 12N BETWEEN 114W AND 126W. 
GLOBAL MODEL GUIDANCE ALSO INDICATES LONG-PERIOD SW SWELL...IN 
THE RANGE OF 15 TO 18 SECONDS...IS PROPAGATING NORTHEASTWARD E 
OF 120W. THIS LONG-PERIOD SW SWELL HAS REACHED THE MEXICO AND 
CENTRAL AMERICAN COASTS PROVIDING FOR HEAVY SURF AND THE 
POSSIBILITY OF RIP CURRENTS.

IN THE VICINITY OF THE GULF OF PAPAGAYO...NE TO E WINDS OF 20 TO 
25 KT ARE FORECAST TO BEGIN DURING THE OVERNIGHT HOURS EARLY 
SATURDAY AND PERSIST THROUGHOUT THE DAY INTO THE LATE AFTERNOON 
SATURDAY. SEAS ARE EXPECTED TO BUILD TO 10 FT IN MIXED WIND 
WAVES AND THE SW SWELL MENTIONED ABOVE.

$$
HUFFMAN