Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 051004
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC THU MAR 05 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC. 

...SPECIAL FEATURES...

...GULF OF TEHUANTEPEC STORM WARNING...

STRONG HIGH PRESSURE BEHIND A COLD FRONT PUSHING SOUTHWARD INTO 
SOUTHERN MEXICO BY THURSDAY EVENING WILL INDUCE A TIGHT PRESSURE 
GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC AND FUNNEL COLD AIR 
THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC DURING THE 
LATE NIGHT HOURS OF THURSDAY AND EARLY MORNING HOURS OF FRIDAY.  
THE WIND SPEEDS ARE FORECAST TO INCREASE TO 40 KNOTS...GALE 
FORCE BY 06/0600 UTC ON FRIDAY MORNING. THE SEA HEIGHTS WILL 
RANGE FROM 8 TO 10 FEET. THE WIND SPEEDS ARE EXPECTED TO 
INCREASE TO 50 KNOTS...STORM FORCE BY 07/06OO UTC...EARLY ON 
SATURDAY MORNING. THE SEA HEIGHTS ARE BEING FORECAST TO REACH TO 
AT LEAST 19 FEET. GALE-FORCE WINDS ARE FORECAST TO CONTINUE FOR 
THE NEXT 24 HOURS ALSO AFTER THE STORM EVENT. THE GALE-FORCE 
WIND EVENT STARTS FIRST, EARLY ON FRIDAY. THE STORM-FORCE WIND 
EVENT STARTS 24 HOURS AFTER THE GALE-FORCE WIND EVENT STARTS.

A ROUND OF 20-25 KNOT WINDS STARTS IN THE GULF OF PAPAGAYO AREA 
AT THE SAME TIME MORE OR LESS AS THE GULF OF TEHUANTEPEC GALE-
FORCE WIND EVENT STARTS. THE WIND AND SWELL FROM EACH EVENT IN 
EACH GULF AREA EVENTUALLY CAUSES THE WINDS AND SEAS FROM THOSE 
EVENTS TO MOVE DOWNSTREAM AND TO MERGE IN THE AREA GENERALLY 
FROM 06N TO 12N BETWEEN 90W AND 106W.

THE GULF OF PANAMA AREA WILL EXPERIENCE A FEW SHORT-LIVED ROUNDS 
OF 20 KNOT WINDS DURING THE FIRST 48 HOURS OF THE FORECAST 
CYCLE. A BURST OF 20-25 KNOT WINDS AND 7 FOOT SEA HEIGHTS BEGINS 
AROUND 54 HOURS. MORE PULSING OF AT LEAST 20 KNOT WINDS 
CONTINUES INTO THE END OF THE 72-HOUR TIME OF THE FORECAST 
CYCLE.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

ITCZ FROM 08N122W TO 07N124W BEYOND 08N140W.05N96W TO 03N104W. 
NO SIGNIFICANT CONVECTIVE PRECIPITATION.

...DISCUSSION... 

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 32N120W 
CYCLONIC CIRCULATION CENTER...TO 22N124W AND 09N124W. 
COMPARATIVELY DRIER AIR IN SUBSIDENCE IS APPARENT IN WATER VAPOR 
SATELLITE IMAGERY FROM 20N NORTHWARD FROM 130W EASTWARD. 
MULTILAYERED MOISTURE COVERS THE AREA FROM 10N NORTHWARD FROM 
130W WESTWARD. 

ONE BRANCH OF A SURFACE RIDGE PASSES THROUGH 32N135W BEYOND 
22N146W. A SECOND BRANCH OF A RIDGE PASSES THROUGH 32N131W TO 
22N119W TO 13N104W.

AN EAST-TO-WEST SURFACE TROUGH IS ALONG 04N95W...TO A 1010 MB 
LOW PRESSURE CENTER THAT IS NEAR 05N98W...TO 03N105W AND 
03N108W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO 
ISOLATED STRONG WITHIN 150 NM TO THE NORTH OF THE TROUGH BETWEEN 
95W AND 105W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND OTHER 
POSSIBLE RAINSHOWERS COVER THE REST OF THE AREA THAT GOES FROM 
THE EQUATOR TO 08N BETWEEN 95W AND 109W. 

A NORTH-TO-SOUTH SURFACE TROUGH IS ALONG 12N115W 09N116W 
05N117W. CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 08N TO 
09N BETWEEN 115W AND 116W.

SCATTEROMETER DATA FROM 05/038 UTC SHOW FRESH-TO-STRONG WINDS 
FROM 08N TO 11N BETWEEN 114W AND 118W...AND FROM 10N TO 14N 
BETWEEN 126W AND 132W. EXPECT THESE WINDS TO REMAIN IN THE SAME 
AREA AND EXPAND IN AREAL COVERAGE FROM 10N TO 17N FROM 116W 
WESTWARD AT 24 HOURS. SEA HEIGHTS SHOULD BE IN THE 8 TO 9 FOOT 
RANGE. EXPECT LITTLE CHANGE IN WINDS AND SEAS FOR 48 HOURS.

$$
MT