000
AXPZ20 KNHC 232132
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

THE ITCZ AXIS EXTENDS FROM 05N93W TO 08N114W TO 03N140W. 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 01N  
TO 04N BETWEEN 88W AND 92W...AND ALSO WITHIN 120 NM S OF THE 
AXIS BETWEEN 112W AND 118W.

ALSO...SCATTERED MODERATE CONVECTION IS FROM 03N TO 06N BETWEEN 
80W AND 82W UNDER AN AREA OF UPPER LEVEL DIFFLUENCE.

...DISCUSSION... 

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N117W TO 
25N122W TO 13N130W. UPPER LEVEL SOUTHWEST WIND FLOW IS WITHIN 
420 NM TO 580 NM TO THE EAST AND SOUTHEAST OF THE TROUGH WHICH 
IS TRANSPORTING DEEP TROPICAL MOISTURE TO THE NORTHEAST. THE 
SOUTHWEST WIND FLOW IS MOVING FROM 11N125W BEYOND 25N108W INTO 
MEXICO. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW 
COVERS THE AREA TO THE EAST OF THE SOUTHWEST WIND FLOW... FROM 
MEXICO AND CENTRAL AMERICA TO THE ITCZ.

A SURFACE RIDGE EXTENDS FROM A 1032 MB HIGH PRESSURE CENTER THAT 
IS NEAR 35N144W THROUGH 32N139W TO 18N106W. THE PRESSURE 
GRADIENT SW OF THE RIDGE AND N OF THE LOWER PRESSURES ASSOCIATED 
WITH THE ITCZ IS TIGHT ENOUGH TO SUPPORT FRESH TO STRONG NE 
TRADES ACROSS THE W CENTRAL WATERS. COMBINED SEAS ARE 8-11 FT IN 
MIXED NE WIND WAVES AND LONG PERIOD SW AND NW SWELLS. THESE 
CONDITIONS ARE FORECAST TO PERSIST ACROSS THE W CENTRAL WATERS 
THROUGH THE NEXT 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 8-11 
FT THAT ARE PROPAGATING SOUTHWARD INTO THE NORTH CENTRAL PART OF 
THE DISCUSSION AREA. THESE SEAS WILL PERSIST THROUGH EARLY FRI 
GRADUALLY SUBSIDING TO LESS THAN 8 FT BY SAT AFTERNOON AS THE 
GALE FORCE WIND EVENT THAT IS TAKING PLACE ENDS.

THE GULF OF CALIFORNIA...A SURFACE TROUGH EXTENDS FROM SOUTHWEST 
ARIZONA INTO THE FAR NORTHWEST SECTION OF THE GULF OF 
CALIFORNIA. THE SURFACE PRESSURE GRADIENT THAT SURROUNDS THIS 
TROUGH WILL STRENGTHEN THIS EVENING GIVING SOUTH-TO-SOUTHWEST 
WIND SPEEDS OF 20-25 KT ON THE EASTERN SIDE OF THE TROUGH. 
PULSES OF THESE STRONGER WIND SPEEDS WILL PULSE FROM THE 
MIDNIGHT/EARLY MORNING HOURS UNTIL THE MIDDAY HOURS FOR TONIGHT 
AND AGAIN FRI NIGHT. THE SEA HEIGHTS WILL BE LOWER THAN 8 FEET 
DURING THE NEXT 48 HOURS.

GULF OF PAPAGAYO...GAP WIND FLOW WILL PULSE TO FRESH TO STRONG 
LEVELS LATE TONIGHT INTO EARLY FRI WITH THE ASSISTANCE OF 
NOCTURNAL DRAINAGE FLOW.

$$ 
LEWITSKY