000
AXPZ20 KNHC 040926
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1005 UTC WED MAY 04 2016

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
0900 UTC.

...SPECIAL FEATURES...

A LATE SEASON GULF OF TEHUANTEPEC GAP WIND EVENT WILL BE INDUCED
BY A COLD FRONT CURRENTLY MOVING ACROSS THE GULF OF MEXICO.
NORTHERLY WINDS AT 20-30 KT WILL BEGIN TO SUDDENLY SURGE INTO
THE TEHUANTEPEC AREA TONIGHT BUILDING SEAS TO AROUND 9 FT BY
LATE THU. WINDS ARE EXPECTED TO FURTHER INCREASE TO MINIMAL GALE
FORCE LATE THU NIGHT INTO FRI MORNING WITH SEAS BUILDING TO 11-
12 FT IN AND DOWNSTREAM OF THE GULF. WINDS ARE EXPECTED TO
DIMINISH BELOW GALE FORCE LATE FRI MORNING...BUT THIS GAP WIND
EVENT IS FORECAST TO CONTINUE THROUGH SAT MORNING. AS A
RESULT...A GALE WARNING HAS BEEN ISSUED WITH THIS FORECAST
PACKAGE.

CLIMATOLOGICALLY SPEAKING...THE FINAL GALE FORCE WIND EVENT
OCCURS IN THE GULF OF TEHUANTEPEC IN LATE MARCH OR EARLY APRIL.
SINCE RECORDS WERE KEPT IN 1999...ONLY THREE GALE FORCE WIND
EVENTS...WINDS IN THE 35-40 KT RANGE...HAVE OCCURRED IN THE
MONTH OF MAY. THESE EVENTS COINCIDED WITH EL NINO CONDITIONS
DURING THE PREVIOUS WINTER TIME.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS FROM 12N87W TO A 1008 MB LOW PRES
NEAR 07.5N97W TO 08N105W. THE ITCZ CONTINUES FROM 08N105W TO
06N120W TO BEYOND 05N140W. CLUSTERS OF MODERATE TO SCATTERED
STRONG CONVECTION ARE NOTED WITHIN 90 NM OF TROUGH BETWEEN 100W
AND 102W...WITHIN 120 NM N OF AXIS BETWEEN 117W AND 121W...AND
WITHIN 135 NM S OF AXIS BETWEEN 124W AND 129W. 

...DISCUSSION...

A COLD FRONT EXTENDS FROM A 1015 MB LOW PRES LOCATED NEAR
30N129W TO 25N130W TO 22N140W. FRESH TO STRONG WINDS PREVAIL W
OF THE FRONT WITH A FRESH SET OF NW SWELLS CURRENTLY REACHING
NEAR 11 FT PER THE MOST RECENT ALTIMETER PASS. THE LOW PRES WILL
MOVE INTO THE FORECAST AREA REACHING NEAR 29N124W IN ABOUT 24
HOURS. THE ASSOCIATED COLD FRONT WILL CONTINUE TO PROPAGATE
EASTWARD BEFORE DISSIPATING BY LATE THU. THE NW SWELL WILL
SPREAD S AND E OVER THE NW WATERS DURING THE NEXT COUPLE OF DAYS
WHILE GRADUALLY SUBSIDING. 

A RIDGE DOMINATES THE REMAINDER OF THE FORECAST WATERS N OF 15N
W OF 110W. THE PRES GRADIENT BETWEEN THIS RIDGE AND LOWER
PRESSURE IN THE VICINITY OF THE ITCZ IS SUPPORTING MODERATE TO
LOCALLY FRESH TRADES MAINLY FROM 07N TO 15N W OF 120W. HIGH
PRESSURE BUILDING BEHIND THE FRONT WILL BRING SOME INCREASE IN
THE TRADE WIND FLOW OVER THE WEST-CENTRAL WATERS TODAY. MARINE
GUIDANCE SUGGESTS MODERATE TO FRESH TRADE WINDS AND SEAS OF 7-8
FT THROUGH FRI. 

A WEAK LOW PRES OF 1008 MB HAS DEVELOPED ALONG THE MONSOON
TROUGH AND IS MOVING WESTWARD. A CYCLONIC TURNING IS NOTED ON
SATELLITE IMAGERY. THIS SYSTEM IS FORECAST TO DISSIPATE IN
ABOUT 24 HOURS. 

GULF OF CALIFORNIA...A SURFACE TROUGH WILL DEVELOP OVER SOUTHERN
CALIFORNIA AND NORTHERN BAJA TONIGHT AND THU. S-SW WINDS IN THE
20 TO 25 KT RANGE ARE EXPECTED TO DEVELOP E OF THE TROUGH AND N
OF 29.5N AS THE TROUGH DEEPENS THU NIGHT INTO FRI MORNING.

$$ 
GR