000
AXPZ20 KNHC 221520
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE APR 22 2014

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
WEAK MONSOON TROUGH EXTENDS FROM 09N85W TO 06N92W. THE ITCZ AXIS 
CONTINUES FROM 06N92W TO 05N110W TO 06N130W TO 05N140W. ISOLATED 
TO SCATTERED MODERATE CONVECTION IS FROM 04N TO 07N E OF 84W. 
SCATTERED MODERATE TO STRONG CONVECTION CAN BE FOUND FROM 02N TO 
06N W OF 134W. 

...DISCUSSION...                                       

ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM 31N125W TO BEYOND 
25N140W. THIS TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE 
FORECAST REGION NEAR 30N126W THEN CONTINUES SW TO 25N140W. FRESH 
TO STRONG WINDS FOLLOW THE FRONT WITH SEAS TO 9 FT. NO 
SIGNIFICANT WEATHER IS ASSOCIATED WITH THE FRONT WHICH IS 
FORECAST TO DISSIPATE ACROSS THE N WATERS LATER TODAY. AN UPPER 
LEVEL RIDGE DOMINATES THE BAJA CALIFORNIA PENINSULA AND NW 
MEXICO. MODERATE TO STRONG MID TO UPPER LEVEL SUBSIDENCE AND 
IMPLIED DRY AIR MASS IS NOTED ON WATER VAPOR IMAGERY N OF 17N E 
OF 120W AND FROM 19N-25N W OF 1305W. IN THE DEEP TROPICS...AN 
UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 7N128W. 
UPPER DIFFLUENT ON THE WEST SIDE OF THIS ANTICYCLONE IS HELPING 
TO INDUCE CONVECTION W OF 134W. ANOTHER UPPER LEVEL ANTICYCLONIC 
CIRCULATION IS NEAR 7N98W. A RIDGE FROM NORTHERN SOUTH AMERICA 
EXTENDS WESTWARD COVERING MOST OF CENTRAL AMERICA. 

A 1030 MB HIGH PRES LOCATED NEAR 33N147W EXTENDS A RIDGE SE 
ACROSS THE FORECAST WATERS TO NEAR 20N110W. TRADE WINDS OF 15-20 
KT ARE NOTED PER SCATTEROMETER DATA ON THE SOUTHERN PERIPHERY OF 
THE RIDGE AND N OF THE ITCZ AXIS WITH SEAS TO 8 FT. THE HIGH 
PRES WILL MOVE EASTWARD TO A POSITION NEAR 33N137W BY 24 HOURS. 
THE TRADE WIND FLOW IS EXPECTED TO INCREASE SOME AS PRES 
GRADIENT TIGHTENS BETWEEN THE HIGH AND LOWER PRES ALONG THE ITCZ 
AXIS. IN ADDITION...EXPECT INCREASING NW TO N WINDS WITH 
BUILDING SEAS TO AROUND 11 FT OFF OF NORTHERN BAJA  
CALIFORNIA...MAINLY N OF 28N E OF 123W BY WED MORNING.

AN AREA MODERATE TO STRONG CONVECTION IS FROM 09N TO 12N BETWEEN 
105W AND 114W. A DIFFLUENT PATTERN ALOFT IS ENHANCING THIS 
CONVECTIVE ACTIVITY. 
 
LONG PERIOD NW SWELLS...WITH A LEADING EDGE PERIOD OF 17-18 
SECONDS...ARE SPREADING SE ACROSS THE N WATERS RAISING SEAS UP 
TO 9 FT N OF 20N W OF 112W. THIS SWELL EVENT WILL MIX WITH 
SHORTER PERIOD NE SWELL FROM THE TRADE WIND FLOW TO COVER MOST 
OF THE WATERS W OF 110W BY LATE TODAY. CROSS EQUATORIAL SW SWELL 
DOMINATES THE REMAINDER OF THE FORECAST WATERS MAINLY E OF 110W. 
LARGE SWELLS FROM THE SOUTHERN HEMISPHERE...WITH WAVE PERIOD OF 
20-22 SECONDS...WILL CROSS THE EQUATOR ON WED AND WILL PROPAGATE 
ACROSS THE SOUTH WATERS ON THU RAISING SEAS UP TO 10 FT E OF 
130W AND S OF A LINE FROM 14N130W TO 12N112W TO 3.4S92W. BASED 
ON WAVE WATCH GUIDANCE...THIS SWELL EVENT IS FORECAST TO REACH 
THE MEXICAN COAST E OF 110W THU NIGHT...AND THE SOUTH PORTION OF 
THE GULF OF CALIFORNIA OR SEA OF CORTEZ ON FRI.

EARLY THIS MORNING...A COUPLE OF SHIP OBSERVATIONS INDICATED NE 
WINDS IN THE 25-30 KT RANGE ACROSS THE GULF OF PAPAGAYO. WINDS 
ARE EXPECTED TO PULSE TO 20 KT ACROSS THIS AREA DURING THE 
OVERNIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE OF THE 
NOCTURNAL DRAINAGE FLOW THROUGH THE FORECAST PERIOD.  
 
$$ 
GR