000
AXPZ20 KNHC 231003
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC THU APR 23 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. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

THE ITCZ IS ALONG 03N903W 05N95W 04N101W 06N110W...AND THEN IT 
RESUMES FROM 05N124W TO 03N133W TO 04N140W. CONVECTIVE 
PRECIPITATION...SCATTERED MODERATE WITHIN 240 NM ON EITHER SIDE 
OF THE ITCZ BETWEEN 96W AND 99W...AND BETWEEN 104W AND 109W. 
 
A SURFACE TROUGH IS ALONG 12N114W 12N119W 06N123W. CONVECTIVE 
PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG WITHIN 90 
NM ON EITHER SIDE OF TROUGH. 

...DISCUSSION... 

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N118W TO 
25N124W TO 15N130W. UPPER LEVEL SOUTHWEST WIND FLOW IS WITHIN 
500 NM TO 600 NM TO THE EAST AND SOUTHEAST OF THE TROUGH. THE 
SOUTHWEST WIND FLOW IS MOVING FROM 11N130W BEYOND 25N109W INTO 
MEXICO. BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW 
COVERS THE AREA THAT IS TO THE EAST OF THE SOUTHWEST WIND 
FLOW... FROM MEXICO AND CENTRAL AMERICA TO THE ITCZ. A SURFACE 
RIDGE EXTENDS FROM A 1031 MB HIGH PRESSURE CENTER THAT IS NEAR 
36N144W...THROUGH 32N138W TO 22N133W...TO 19N122W...TO 17N104W.

THE SURFACE TRADE WIND FLOW IS REACHING 20 TO 25 KNOTS FROM THE 
NORTHEAST...BASED ON CURRENT OBSERVATIONS. THE SURFACE PRESSURE 
GRADIENT BETWEEN THE 1031 MB HIGH PRESSURE CENTER AND THE ITCZ 
IS SUPPORTING THE TRADE WIND FLOW FROM 10N TO 16N FROM 132W 
WESTWARD. THE SEA HEIGHTS ARE RANGING FROM 9 TO 11 FEET IN MIXED 
SWELL. A LARGER AREA OF WIND SPEEDS 20 KNOTS OR LESS WITH 8 TO 
10 FOOT SEA HEIGHTS COVERS THE EASTERN PACIFIC OCEAN FROM 05N TO 
23N FROM 126W WESTWARD AT THIS MOMENT. EXPECT MORE COMPARATIVELY 
SMALLER AREAS OF 20 TO 25 NORTHEAST TRADE WINDS TO BE INSIDE 
COMPARATIVELY BIGGER AREAS OF WIND SPEEDS OF 20 KNOTS OR LESS 
AND 8 TO 10 FOOT SEA HEIGHTS FOR THE 48 HOURS.
 
GALE FORCE NORTHERLY WINDS ARE BLOWING IN THE WATERS THAT ARE 
OFF THE NORTHERN CALIFORNIA REDWOOD COAST. THESE WINDS ARE 
GENERATING NORTHERLY SWELL WITH SEA HEIGHTS THAT RANGE FROM 9 TO 
11 FEET...THAT ARE PROPAGATING SOUTHWARD INTO THE NORTH CENTRAL 
PART OF THE DISCUSSION AREA. THESE SEAS WILL PERSIST THROUGH 
EARLY FRIDAY. THEY WILL SUBSIDE GRADUALLY ON FRIDAY AFTERNOON 
AND AT NIGHT...AS THE GALE FORCE WIND EVENT THAT IS TAKING PLACE 
TO THE NORTH OF THE AREA ENDS.

THE GULF OF CALIFORNIA...A SURFACE TROUGH EXTENDS FROM SOUTHERN 
NEVADA INTO SOUTHWESTERN ARIZONA...AND INTO THE NORTHERN 
SECTIONS OF THE GULF OF CALIFORNIA. THE SURFACE PRESSURE 
GRADIENT THAT SURROUNDS THIS TROUGH IS COMPARATIVELY STRONGER AT 
THE MOMENT...GIVING SOUTH-TO-SOUTHWEST WIND SPEEDS OF 20 TO 25 
KNOTS...ON THE EASTERN SIDE OF THE TROUGH. PULSES OF 20 TO 25 
KNOT WIND SPEEDS WILL BE PRESENT...FROM 30N NORTHWARD...FROM THE 
MIDNIGHT/EARLY MORNING HOURS UNTIL THE MIDDAY HOURS FOR TODAY 
THURSDAY...AND FOR TOMORROW FRIDAY DURING THE SAME TIME PERIOD. 
THE SEA HEIGHTS WILL BE LOWER THAN 8 FEET DURING THE NEXT 48 
HOURS.

$$
MT