000
AXPZ20 KNHC 082126
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                          
2205 UTC MON APR 08 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 
2000 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 10N83W TO 07N90W. ITCZ 
AXIS WAS ANALYZED FROM 07N90W TO 05N102W TO 07N109W THEN 
CONTINUES FROM 04N114W TO 03N126W. SCATTERED MODERATE CONVECTION 
WAS WITHIN 120 NM N OF THE AXIS BETWEEN 104N AND 107W AS WELL AS 
WITHIN 120 NM N OF THE AXIS BETWEEN 119W AND 123W. A TROUGH 
BISECTS THE ITCZ FROM 10N107W TO 03N113W...SCATTERED MODERATE 
CONVECTION WAS WITHIN 300 NM W OF THE TROUGH FROM 06N TO 08N AND 
WITHIN 120 NM W OF THE TROUGH FROM 08N TO 10N.

...DISCUSSION...                                             
GULF OF CALIFORNIA...A COLD FRONT WILL PASS THROUGH THE GULF OF 
CALIFORNIA N OF 29N THIS EVENING. SOUTHERLY WINDS WILL INCREASE 
TO A FRESH TO STRONG BREEZE AHEAD OF THE FRONT AND SHIFT 
WESTERLY BEHIND THE FRONT. FUNNELING THROUGH MOUNTAIN PASSES 
WILL MAKE WINDS LOCALLY STRONGER...POSSIBLY TO GALE FORCE. WINDS 
WILL DIMINISH BY TUE MORNING AS THE FRONT RACES EASTWARD.

RELATIVELY ZONAL WESTERLY FLOW ASSOCIATED WITH A WIDE 90 KT 
UPPER JET CENTERED ALONG 20N E OF 125W INTO SOUTHERN MEXICO 
DOMINATES MUCH OF THE PACIFIC FORECAST AREA WITH A FEW 
EXCEPTIONS. TO THE W OF THE JET...AN UPPER TROUGH FROM 23N147W 
TO 02N128W IS CAUSING THE JET AXIS TO DIP SOUTHWARD OVER W 
WATERS AND TAP INTO TROPICAL MOISTURE ALOFT. THIS MOISTURE IS 
MANIFESTED AS CIRRUS FROM 07N TO 21N W OF 120W. TO THE S OF THE 
JET...UPPER DIFFLUENCE TO THE W OF A WEAK ANTICYCLONE CENTERED 
NEAR 08N100W IS ENHANCING SCATTERED MODERATE CONVECTION NEAR A 
SURFACE TROUGH FOUND FROM 10N107W TO 03N113W. THIS CONVECTION IS 
DESCRIBED IN THE SECTION ABOVE. TO THE N OF THE JET...A DEEP-
LAYERED TROUGH HAS MOVED INTO THE BAJA CALIFORNIA PENINSULA AND 
NORTHWESTERN MEXICO AND HAS DIRECTED UPPER WINDS MORE 
NORTHWESTERLY OVER FORECAST WATERS N OF 25N E OF 130W. THE 
NORTHERN STREAM JET ASSOCIATED WITH THIS TROUGH WILL MERGE WITH 
THE ZONAL JET OVER MEXICO OVER THE NEXT 48 HOURS.

THE 1030 MB SUBTROPICAL SURFACE HIGH LIES NEAR 35N138W AND 
EXTENDS A RIDGE SOUTHEASTWARD TO 15N106W. THE PRESSURE GRADIENT 
BETWEEN THE SUBTROPICAL RIDGE AND THE ITCZ IS FORCING FRESH TO 
STRONG NE TRADE WINDS FROM 07N-22N W OF 129W AS SEEN BY THE 1534 
UTC WINDSAT PASS AS WELL AS SHIP VRSR WHO REPORTED 25 KT WINDS 
NEAR 20N129W AT 1800 UTC. THE HIGH IS EXPECTED TO REMAIN 
RELATIVELY STATIONARY AND SHOW LITTLE CHANGE IN PRESSURE THROUGH 
EARLY TUE. 

THE PRESSURE GRADIENT ON THE E SIDE OF THE SUBTROPICAL RIDGE IS 
FORCING FRESH TO STRONG NW WINDS N OF 27N ALONG THE PACIFIC 
COAST OF THE BAJA CALIFORNIA PENINSULA TO 127W AS SEEN BY THE 
1714 UTC ASCAT PASS. A GALE WARNING IS IN EFFECT FOR WATERS N OF 
30N TONIGHT INTO TUE. 15-17 SECOND PERIOD NW SWELL CURRENTLY 
LIES OFF THE BAJA CALIFORNIA PACIFIC COAST. THIS DAMPENING NW 
SWELL IS COMBINING WITH NW WIND WAVES IN PACIFIC WATERS OFF THE 
BAJA CALIFORNIA PENINSULA...WITH SEAS EXPECTED TO REACH OVER 15 
FT S OF 30N ON TUE. THE LEADING EDGE OF THE NW SWELL 
TRAIN...WITH PERIODS EXCEEDING 20 SECONDS...HAS ALREADY CLIPPED 
THE CENTRAL MEXICAN COAST NEAR CABO CORRIENTES AND WILL REACH 
THE GALAPAGOS ISLAND BY TUE AFTERNOON.

$$
SCHAUER