000
AXPZ20 KNHC 162206
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN APR 15 2012

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

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

ITCZ AXIS FROM 03N100W TO 07N108W TO 03.5N124W TO 03.5N133W TO 
03N140W. NO MONSOON TROUGH APPARENT. SCATTERED MODERATE TO 
STRONG CONVECTION NOTED WITHIN 90 NM S AND 150 NM N OF AXIS 
BETWEEN 108W AND 127W. SCATTERED MODERATE CONVECTION NOTED 
WITHIN 150 NM N OF AXIS W OF 127W.

...DISCUSSION...

AT UPPER LEVELS...NEARLY ZONAL UPPER LEVEL FLOW PREVAILS ACROSS 
THE AREA N OF 10N THIS AFTERNOON. A NEGATIVE TILT UPPER CYCLONE 
MOVING NE NEAR THE PACIFIC NW OF THE U.S. TRAILS A MIDDLE/UPPER 
LEVEL TROUGH SW AND WAS REACHING THE FAR NW CORNER OF THE AREA 
THIS AFTERNOON. A LINGERING MIDDLE LEVEL TROUGH WAS JUST AHEAD 
OF THIS TROUGHING...FROM 30N132W TO 24N150W. FROM 24N S TO 
10N...A VERY BROAD AND NEARLY FLAT RIDGE-TROUGH-RIDGE PATTERN 
PREVAILS BETWEEN 85W AND 145W...WITH MIDDLE/UPPER TROUGH ALONG 
114W AND UPPER ANTICYCLONE CENTERED NEAR 11.5N90W. BROAD LLVL 
CONVERGENCE OCCURRING ALONG AND N OF THE ITCZ W OF 110W 
CONTINUED TO INDUCE ASSOCIATED CONVECTION DESCRIBED ABOVE...AND 
WAS AIDING IN MAINTAINING UPPER RIDGING OVERHEAD OF THIS ACTIVE 
CONVECTION. THE PROGRESSIVE UPPER PATTERN N OF 24N WILL NUDGE 
THE BROAD TROUGH ALONG 114W E AND NE ACROSS THE BACKSIDE OF THE 
RIDGE ALONG 90W DURING THE NEXT 24 TO 36 HOURS...WITH LITTLE 
CHANGES IN THE PATTERN S OF 24N.

AT LOWER LEVELS...HIGH PRES DOMINATES THE AREA W OF 108W...WITH 
RIDGE CENTERED ON A NEARLY STATIONARY 1028 MB HIGH NEAR 30N134W. 
LOW PRES OVER INTERIOR MEXICO IS ENHANCING NW WINDS IN THE GULF 
OF CALIFORNIA N OF 26N AND W OF THE BAJA PENINSULA. S OF THE 
RIDGE...A BROAD AREA OF MODERATE TO FRESH NE TRADE WINDS IS 
LOCATED FROM 06N TO 21N W OF 130W AND FROM 06N TO 15N BETWEEN 
124W AND 130W...WHERE SEAS ARE CURRENTLY RUNNING 8-1O T WITH NW 
SWELL. THE NW SWELL WILL FADE IN THE NEXT 24 HOURS LEADING TO A 
SLOW SUBSIDING TREND ACROSS THE REGION. AN AREA OF 9-11 FT SEAS 
IS LOCATED SW OF BAJA CALIFORNIA FROM 18N TO 26N...AND ANOTHER 
AREA OF 9-11 FT SEAS IS LOCATED IN THE DEEP TROPICS FROM 07N TO 
14N W OF 130W.

EXPECT VERY LITTLE CHANGE TO THE CURRENT SYNOPTIC PATTERN FOR 
THE NEXT 24-36 HOURS. HIGH PRES RIDGE NEAR 30N133W WILL REMAIN 
NEARLY STATIONARY AND DEFLECT A WEAKENING COLD FRONT JUST NW  
OF THE DISCUSSION AREA. LOW PRES OVER MEXICO WILL WEAKEN 
SLIGHTLY ON TUE...BUT WILL CONTINUE TO PRODUCE SUFFICIENT PRES 
GRADIENT WITHIN THE GULF OF CALIFORNIA TO PRODUCE NWLY WINDS 
20-25 KT THIS EVENING AND TONIGHT BEFORE FALLING BELOW 20 KT 
TUE. AT THE SAME TIME... WILL DIMINISH OVER ENTIRE NE PORTION. 
MODERATE TO FRESH TRADEWINDS WILL CONTINUE S OF 20N W OF 
130W...WITH SEAS SLOWLY SUBSIDING TO 8-9 FT BY TUE.

A TIGHTER PRES GRADIENT IS EXPECTED TO DEVELOP ALONG THE COAST 
OF CALIFORNIA TUE NIGHT WITH NW WINDS INCREASING TO 25 KT N OF 
30N. NNW SWELL TO 9 FT AND NLY WINDS TO 20 KT CAN BE EXPECTED N 
OF 27N BETWEEN 118W AND 125W BY WED MORNING. MODEL GUIDANCE ALSO
INDICATES THE POTENTIAL FOR 20-25 KT NORTHERLY WINDS IN THE GULF 
OF TEHUANTEPEC LATE TUE NIGHT FROM HIGH PRES OVER INTERIOR MEXICO
AND LOW PRES IN THE EASTERN NORTH PACIFIC SW OF CENTRAL AMERICA.

$$
STRIPLING