000
AXPZ20 KNHC 072116
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                        
2205 UTC SUN APR 07 2013

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 
1945 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N84W TO 06N93W. THE 
ITCZ AXIS WAS ANALYZED FROM 06N93W TO 06N113W TO 02N140W. 
SCATTERED MODERATE CONVECTION WAS WITHIN 90 NM EITHER SIDE OF THE 
AXIS E OF 86W...S OF THE AXIS TO 03N BETWEEN 110W AND 118W...AND 
WITHIN 330 NM N OF THE AXIS BETWEEN 110W AND 127W.
 
...DISCUSSION...                                               
GULF OF CALIFORNIA...A COLD FRONT WILL PASS THROUGH THE GULF OF 
CALIFORNIA N OF 29N MON EVENING. SOUTHERLY WINDS WILL INCREASE 
TO A FRESH TO STRONG BREEZE AHEAD OF THE FRONT MON AFTERNOON AND 
SHIFT WESTERLY BEHIND THE FRONT MON EVENING. FUNNELING THROUGH 
MOUNTAIN PASSES WILL MAKE WINDS LOCALLY STRONGER. WINDS WILL 
DIMINISH BY TUE MORNING AS THE FRONT RACES EASTWARD.

RELATIVELY ZONAL WESTERLY FLOW ASSOCIATED WITH A WIDE 60 KT 
WESTERLY UPPER JET CENTERED FROM 07N140W TO 16N140W AND ALONG 
16N INTO SOUTHERN MEXICO DOMINATES MUCH OF THE PACIFIC FORECAST 
AREA WITH A FEW EXCEPTIONS. TO THE W OF THE AREA...A COMPLEX 
UPPER LOW IS CAUSING THE JET AXIS TO DIP SOUTHWARD AND TAP INTO 
TROPICAL MOISTURE ALOFT. THIS MOISTURE IS MANIFESTED AS CIRRUS 
FROM 06N TO 20N W OF 130W. TO THE S OF THE JET...UPPER 
DIFFLUENCE ASSOCIATED WITH A WEAK ANTICYCLONE CENTERED NEAR THE 
GULF OF PANAMA IS ENHANCING CONVECTION WITHIN 120 NM OF THE 
COAST OF COLOMBIA FROM 04N TO 07N AS WELL AS ALONG THE MONSOON 
TROUGH E OF 86W TO THE COAST OF COSTA RICA. A LARGER AREA OF 
CONVECTION LIES ALONG THE ITCZ BETWEEN 110W-130W AND IS 
DESCRIBED IN THE SECTION ABOVE. THIS AREA IS CONINCIDENT WITH 
PRECIPITABLE WATER VALUES AROUND 60 MILLIMETERS AND A REGION OF 
STRONG UPPER DIFFLUENCE. TO THE N OF THE JET...WINDS ARE 
BEGINNING TO SHIFT NW ON THE SOUTH EDGE OF A DEEPENING UPPER 
TROUGH OVER THE WESTERN U.S. THAT WILL TURN THE PATTERN OVER 
MUCH OF THE FORECAST AREA MORE AMPLIFIED THROUGH TUE.

THE 1030 MB SUBTROPICAL SURFACE HIGH LIES NEAR 32N141W AND 
EXTENDS A RIDGE SOUTHEASTWARD TO 12N100W. THE PRESSURE GRADIENT 
BETWEEN THE SUBTROPICAL RIDGE AND THE ITCZ IS FORCING FRESH TO 
STRONG NE TRADE WINDS FROM 10N-20N W OF 130W AS SEEN BY THE 1918 
UTC ASCAT PASS. THE HIGH IS EXPECTED TO REMAIN RELATIVELY 
STATIONARY AND SHOW LITTLE CHANGE IN PRESSURE THROUGH TUE. THIS 
SHOULD KEEP THE FRESH TO STRONG TRADE WINDS IN PLACE OVER 
WESTERN WATERS.

THE PRESSURE GRADIENT ON THE E SIDE OF THE SUBTROPICAL RIDGE IS 
FORCING FRESH TO STRONG WINDS N OF 27N ALONG THE PACIFIC COAST 
OF THE BAJA CALIFORNIA PENINSULA TO 123W AS SEEN BY THE 1732 UTC 
ASCAT PASS. FRESH TO STRONG NW WINDS WILL EXPAND AS FAR W AS 
126W MON AND TUE WHEN THE NORTHERN STREAM TROUGH MOVES INTO THE 
WESTERN U.S...SENDING A COLD FRONT THROUGH FAR NE WATERS LATE 
MON. A GALE WARNING IN IN EFFECT FOR WATERS N OF 30N ON MON AND 
TUE. 16-18 SECOND PERIOD NW SWELL CURRENTLY LIES OFF THE BAJA 
CALIFORNIA NORTE COAST. THIS DAMPENING NW SWELL IS COMBINING 
WITH NW WIND WAVES IN PACIFIC WATERS OFF THE BAJA CALIFORNIA 
PENINSULA...WITH SEAS EXPECTED TO REACH 14 FT BY MON AFTERNOON. 
THE LEADING EDGE OF THE NW SWELL TRAIN...WITH PERIODS EXCEEDING 
20 SECONDS...WILL CLIP THE CENTRAL MEXICAN COAST NEAR CABO 
CORRIENTES TONIGHT AND REACH THE GALAPAGOS ISLAND BY TUE 
AFTERNOON.

$$
SCHAUER