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Eastern Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 042215
TWDEP 

TROPICAL WEATHER DISCUSSION                                 
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC MON MAY 04 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC. 

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

THE MONSOON TROUGH EXTENDS FROM 09N86W TO 05N100W TO 08.5N113W 
TO 06N117W...WHERE IT TERMINATES. THE ITCZ EXTENDS FROM 04N121W 
TO 04N136W TO BEYOND 03N140W. SCATTERED MODERATE TO STRONG 
CONVECTION NOTED FROM 03N TO 10N BETWEEN 08W AND 90W...AND 
WITHIN 240 NM S OF TROUGH BETWEEN 96W AND 116W. SCATTERED 
MODERATE TO STRONG CONVECTION NOTED FROM 10N TO 15N BETWEEN 111W 
AND 117W. ISOLATED TO SCATTERED MODERATE ISOLATED STRONG 
CONVECTION NOTED FROM 00N TO BEYOND 03.4S BETWEEN 84W AND 110W. 

...DISCUSSION...    

AT UPPER LEVELS...A BROAD RIDGE COVERS MOST OF THE AREA S OF 20N 
AND W OF 85W...WITH THE RIDGE CENTERED ON AN ANTICYCLONE NEAR 
12.5N111W...EXTENDING NE TO NORTHEASTERN MEXICO AND EXTREME SW 
TEXAS NEAR 30N103W. ACTIVE CONVECTION PERSISTING UNDER THE RIDGE 
THE PAST FEW DAYS HAS DIMINISHED CONSIDERABLY IN AREAL 
COVERAGE...WITH THE MAIN CONVECTIVE ACTIVITY PERSISTING JUST W 
AND NW OF THE ANTICYCLONE. A MIDDLE TO UPPER TROUGH ACROSS NE 
PORTIONS HAS SHIFTED E-NE INTO THE SOUTH HALF OF CALIFORNIA AND 
NORTHERN BAJA...AND IS AIDING IN GENERATING CONVECTION ACROSS 
THE FOUR CORNERS REGION OF THE U.S. UPSTREAM OF THIS TROUGH A 
PAIR OF SHORTWAVE TROUGHS ARE EMBEDDED IN THE WLY FLOW ALOFT. A 
UPPER JET OF S OF THE SHORTWAVE TROUGHS...EXTENDING FROM NEAR 
18N140W NORTHEASTWARD OVER THE RIDGE AND INTO NORTHERN 
MEXICO...AND IS STARTING TO FLATTEN TO RIDGE THERE. THE TWO 
SHORTWAVES ARE FORECAST TO MOVE E-NE AND INLAND ACROSS THE 
WESTERN U.S. THROUGH WED AND WILL COMPLETE A FLATTENING OF THE 
RIDGE. 

AT THE SURFACE...A RIDGE CONTINUES ACROSS W PORTIONS OF THE 
AREA...CENTERED ON A 1030 MB HIGH NEAR 35N146W...AND EXTENDS SE 
TO NEAR 18N106W. MODERATE TO FRESH NE TRADEWINDS PREVAIL S AND 
SE OF THE RIDGE...S OF 22N AND W OF 116W. NE WIND SWELL IN THIS 
ZONE OF TRADES IS MAINTAINING SEAS 7-10 FT WITH MIXED SW SWELL. 
ACROSS THE TROPICS E OF 116W WINDS ARE GENERALLY LIGHT TO 
MODERATE...AND EXPECTED TO REMAIN GENERALLY 15 KT OR LESS... 
EXCEPT FOR THE GULF OF PAPAGAYO...WHERE GAP WINDS ARE EXPECTED 
TO INCREASE TO AROUND 20 KT BRIEFLY TONIGHT AND AGAIN TUE NIGHT. 

LONG PERIOD SOUTHWEST SOUTHERN HEMISPHERIC SWELL HAS BEGUN TO 
SLOWLY SUBSIDE ACROSS ALMOST THE ENTIRE AREA TODAY...WITH SEAS  
STILL 7 TO 10 FT ACROSS MUCH OF THE AREA E OF 128W THIS 
AFTERNOON. PEAK WAVE ENERGY ASSOCIATED WITH THIS EVENT HAS 
ALREADY REACHED THE COASTLINES OF CENTRAL AMERICA AND MEXICO AND 
IS NOW MOVING INTO THE WATERS OF SOUTHERN THROUGH CENTRAL 
CALIFORNIA. THIS SW SWELL WILL CONTINUE TO GRADUALLY SUBSIDE 
THROUGH EARLY WED...WITH WAVE CONDITIONS WITHIN THE SURFZONE AND 
ALONG THE BEACHES GRADUALLY IMPROVING DURING THE NEXT 24-36 
HOURS. 

$$
STRIPLING


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Page last modified: Monday, 04-May-2015 22:16:13 UTC