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Eastern Pacific Tropical Weather Discussion (Text)



000
AXPZ20 KNHC 030239
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SUN MAY 03 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 
0200 UTC. 

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

THE MONSOON TROUGH EXTENDS FROM 07N79W TO 08N92W TO 06N101W TO  
10N116W TO 06N128W TO 06.5N140W. SCATTERED MODERATE TO STRONG 
CONVECTION NOTED WITHIN 120 NM N AND 420 NM S OF TROUGH E OF 
95W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 330 NM 
N AND 420 NM S OF TROUGH BETWEEN 105W AND 133W. 134W.

...DISCUSSION...    

ZONAL FLOW ALOFT COVERING MUCH OF THE AREA YESTERDAY HAS BECOME 
SOMEWHAT AMPLIFIED DURING THE PAST 24 HOURS...AS THE E TO W 
RIDGING ACROSS THE TROPICS HAS BUILT NORTHWARD ALONG 112-114W TO 
CENTRAL BAJA CALIFORNIA. SCATTERED CONVECTION PULSING NEAR THE 
MONSOON TROUGH IS HELPING TO MAINTAIN THIS BROAD RIDGE THAT 
COVERS THE ENTIRE AREA E OF 146W. TO THE NW...A TUTT LIKE TROUGH 
EXTENDS FROM NORTHERN CALIFORNIA SW THROUGH A SERIES OF 
WEAKENING MIDDLE LEVEL CYCLONES THROUGH 25N140W TO NEAR THE E 
COAST OF THE BIG ISLAND OF HAWAII. A TROPICAL JETSTREAM WITH 
PEAK WINDS 85-110 KT ENTERS THE REGION NEAR 16N150W AND MOVES NE 
OVER THE RIDGE THEN DIVES SE AND WEAKENS ACROSS CENTRAL MEXICO 
AND INTO THE BASE OF A BROAD TROUGH ACROSS THE GULF OF MEXICO 
AND NW CARIBBEAN. THE UPPER TROUGH IS FORECAST TO DRAG EWD AND 
INTO SOUTHERN CALIFORNIA BY MON AND BRING STRONG JET DYNAMICS 
ACROSS NE PORTIONS OF THE AREA AND INTO NORTHERN BAJA CALIFORNIA 
BY MON MORNING. 

AT THE SURFACE...A WEAKENING RIDGE CONTINUES ACROSS W 
PORTIONS...CENTERED ON A 1028 MB HIGH NEAR 37N143W...EXTENDING E 
TO THE NW COAST OF THE U.S. AND SE TO NEAR 17N117W. THE PRES 
GRADIENT BETWEEN THE HIGH AND LOWER PRES ALONG THE MONSOON 
TROUGH HAS WEAKENED SLIGHTLY IN THE PAST 24 HOURS...AND MODERATE 
TO FRESH NE TRADEWINDS PREVAIL ACROSS THE AREA W OF 130W. 
AFTERNOON SCATTEROMETER PASSES SUGGESTED WINDS GENERALLY LESS 
THAN 20 KT E OF 120W ACROSS THE AREA THIS AFTERNOON...WITH THE 
LONE EXCEPTION AN ONGOING NORTHERLY GAP WIND EVENT IN THE GULF 
OF TEHUANTEPEC. 

ACTIVE CONVECTION ACROSS THE AREA E OF 90W...AND NEAR THE 
MONSOON TROUGH W OF 105W...HAS INCREASED MODESTLY THIS AFTERNOON 
AND EVENING. THIS ACTIVE CONVECTION IS EXPECTED TO CONTINUE E OF 
130W THROUGH TONIGHT AND THEN SLOWLY DIMINISH SUN THROUGH MON. 

ACROSS THE GULF OF TEHUANTEPEC...NORTHERLY WINDS 20-25 KT WERE 
DEPICTED N OF 14N BY A NOON TIME SCATTEROMETER PASS...WHERE SEAS 
WERE 8 TO 10 FT WITH BUILDING SW SWELL. A WEAK HIGH PRES RIDGE 
IS EXPECTED TO CONTINUE ACROSS THE GULF OF MEXICO THROUGHOUT THE 
REMAINDER OF THE WEEKEND AND MAINTAIN LIGHT TO MODERATE NE WINDS 
FUNNELING ACROSS THE ISTHMUS OF TEHUANTEPEC. THIS SCENARIO IS 
EXPECTED TO PRODUCE NORTHERLY WINDS INCREASING TO 20-30 KT 
TONIGHT AND THEN DIMINISH LESS THAN 20 KT BY SUNDAY AFTERNOON. 

LARGE SW SOUTHERN HEMISPHERIC SWELL CONTINUES TO SPREAD N AND NE 
ACROSS MUCH OF THE AREA TODAY...AND HAS REACHED THE OFFSHORE 
WATERS OF CENTRAL BAJA CALIFORNIA THIS EVENING. MORNING 
ALTIMETER PASSES MEASURED SEAS 12-14 FT W THROUGH SW OF THE 
GALAPAGOS ISLANDS...WHILE SEAS ACROSS THE COLOMBIAN COASTAL 
WATERS HAD REACHED 8 FT. THIS LARGE AND VERY STRONG SWELL WILL 
CONTINUE TO PROPAGATE NORTHWARD ACROSS THE AREA WATERS TONIGHT 
THROUGH SUNDAY NIGHT AND AFFECT THE ENTIRE AREA E OF 132W. 
SIGNIFICANT SWELL WILL ALSO ENTER THE S PORTIONS OF THE GULF OF 
CALIFORNIA...WERE SEAS ARE EXPECTED TO BUILD TO 7-10 FT BY 
SUNDAY AFTERNOON. THESE LARGE VERY LONG PERIOD SWELLS WILL 
GENERATE VERY LARGE SURF AND DANGEROUS MARINE CONDITIONS ALONG 
THE REGIONAL COASTS AND WITHIN THE SURFZONE THROUGHOUT THE 
WEEKEND.

$$
STRIPLING

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Page last modified: Sunday, 03-May-2015 02:39:45 UTC