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000
AXPZ20 KNHC 250334
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JAN 25 2015

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 0300 UTC.


...SPECIAL FEATURES... A GALE WARNING REMAINS IN EFFECT FOR THE GULF OF TEHUANTEPEC. N TO NE WINDS OF 30-40 KT ARE OCCURRING ACROSS THE REGION AS COLD DENSE AIR CONTINUES TO FUNNEL THROUGH THE CHIVELA PASS AND INTO THE GULF. MAX SEAS OF 14-16 FT ARE ASSOCIATED WITH THESE WIND SPEEDS. WINDS ARE FORECAST TO DIMINISH TO MINIMAL GALE FORCE SUN AFTERNOON AND EVENING...THEN INCREASE AGAIN TO 35-40 KT LATE SUN NIGHT INTO MON MORNING AS A REINFORCING PUSH OF COLD AIR OCCURS. THIS IS FORECAST TO BE A LONG DURATION GALE FORCE GAP WIND EVENT. NORTHERLY WINDS IN THE 35-40 KT RANGE ARE EXPECTED TO LIKELY PERSIST THROUGH WED MORNING AS HIGH PRES PERSISTS OVER THE WESTERN GULF THROUGH MID WEEK.


...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 06N77W TO 04N83W TO 07N95W. THE ITCZ CONTINUES FROM 07N95W TO 08N110W TO 07N125W TO 06N140W. SCATTERED MODERATE CONVECTION IS FROM 02N TO 04.5N BETWEEN 83W AND 86W...AND FROM 10N TO 12N BETWEEN 107W AND 110W.


...DISCUSSION... ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE FORECAST AREA W OF 100W. A STRONG CUT-OFF LOW HAS DEVELOPED JUST W OF BAJA CALIFORNIA AND IS CENTERED NEAR 27N117W. A TROUGH EXTENDS FROM THIS UPPER-LEVEL LOW S-SW TO NEAR 13N122W. ABUNDANT MIDDLE TO UPPER LEVEL MOISTURE IS STREAMING E-NE AHEAD OF THE TROUGH AXIS. AN ANTICYCLONE LOCATED OVER NORTHERN COLOMBIA AND WESTERN VENEZUELA EXTENDS A RIDGE ACROSS CENTRAL AMERICA AND SE MEXICO.

AT THE SURFACE...THE STRONG HIGH PRES THAT WAS LOCATED WELL N OF THE AREA DURING THE PREVIOUS DAYS IS WEAKENING AS A COLD FRONT APPROACHES FROM THE WEST. THIS HIGH PRES OF 1023 MB EXTENDS A RIDGE SOUTHWARD TO COVER MOST OF THE DISCUSSION AREA N OF 20N. A WEAK SURFACE TROUGH...FORMERLY ASSOCIATED WITH THE ABOVE MENTIONED UPPER LEVEL TROUGHING...EXTENDS FROM 19N137W TO 12N139W. RECENT SCATTEROMETER DATA PROVIDED OBSERVATIONS OF MODERATE TO FRESH WINDS ACROSS THE SOUTHERN PERIPHERY OF THE RIDGE FROM 15N TO 25N W OF 120W. A NEW TROUGH IS ANALYZED FROM 20N116W TO 11N118W AND IS GENERATING SOME SHOWERS AND TSTM ACTIVITY. A DIFFLUENT PATTERN ALOFT AHEAD OF THE AFOREMENTIONED UPPER-LEVEL TROUGH IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. THIS TROUGH IS FORECAST TO DRIFT EASTWARD.

AN AREA OF LARGE LONG PERIOD NW SWELL...ASSOCIATED WITH A COLD FRONT IN THE CENTRAL PACIFIC NE OF HAWAII...IS PROPAGATING SE THROUGH THE WESTERN WATERS. THESE SWELLS ARE RESULTING IN MAX COMBINED SEAS OF 11-12 FT WITH PERIODS OF 16-18 SECONDS. THE COLD FRONT WILL ENTER THE FAR NW PORTION OF THE AREA AROUND 25/1800 UTC AND EXTEND FROM 30N136W TO 23N140W BY 26/1800 UTC. FRESH TO STRONG NORTHERLY WINDS ARE EXPECTED IN THE WAKE OF THE FRONT WITH BUILDING SEAS OF 9-11 FT. THE EXTENSIVE SWELL TRAIN ASSOCIATED WITH THIS FRONT WITH SEAS OF 8-11 FT WILL CONTINUE TO PROPAGATE ACROSS THE FORECAST WATERS REACHING THE AREA W OF A LINE FROM 30N120W TO 15N130W TO 07N135W BY 48 HOURS.

HIGH PRES OVER THE SOUTHWEST U.S. IN COMBINATION WITH A SURFACE TROUGH ACROSS NW MEXICO HAS TIGHTENED THE PRES GRADIENT IN THE GULF OF CALIFORNIA. WINDS ARE PRESENTLY FRESH TO STRONG FROM N OF 29N WITH SEAS LESS THAN 8 FT. THESE WINDS ARE EXPECTED TO DIMINISH TO 20 KT OR LESS BY LATE TONIGHT INTO EARLY SUN.

GAP WINDS... FRESH TO LOCALLY STRONG WINDS ARE EXPECTED TO INCREASE TO 25 KT TONIGHT AND INTO SUN MORNING THROUGH THE GULF OF PAPAGAYO AS HIGH PRES BUILDS ACROSS THE WESTERN CARIBBEAN. THESE WINDS ARE FORECAST TO LAST THROUGH MON NIGHT INTO TUE MORNING. AT THAT TIME...MARINE GUIDANCE ALSO SUGGESTS INCREASING WINDS ACROSS THE GULF OF FONSECA.

FRESH TO STRONG NORTHERLY WINDS ARE ALSO EXPECTED THROUGH THE GULF OF PANAMA TONIGHT AND INTO SUN MORNING REACHING 25 KT N OF 05N BETWEEN 79W AND 81W.

THE PRES GRADIENT WILL REMAIN STRONG ENOUGH ACROSS THE WESTERN CARIBBEAN THROUGH AT LEAST TUE TO SUPPORT ALL THESE GAP WIND EVENTS.

$$ GR

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