000
AXPZ20 KNHC 281526
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC WED MAY 28 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.

...SPECIAL FEATURES...

TROPICAL STORM AMANDA IS CENTERED NEAR 15.0N 112.0W AT 28/1500 
UTC MOVING NE OR 40 DEGREES AT 3 KT. MAXIMUM SUSTAINED WIND 
SPEED IS 55 KT WITH GUSTS TO 65 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 996 MB. AMANDA IS PRODUCING A CONSIDERABLE AMOUNT OF 
DEEP CONVECTION ESPECIALLY TO THE N OF THE CENTER DUE TO A 
SOUTHERLY SHEAR ENVIRONMENT. NUMEROUS STRONG CONVECTION IS NOTED 
WITHIN 180 NM NE AND 240 NM NW QUADRANTS AND 20 NM S SEMICIRCLE. 
CONTINUED WEAKENING IS FORECAST DURING THE NEXT 48 HOURS AND 
AMANDA IS EXPECTED TO WEAKEN TO A TROPICAL DEPRESSION BY EARLY 
FRI. AMANDA IS FORECAST TO MOVE TOWARD THE NE DURING THE NEXT 
DAY OR TWO...THE WILL MAKE A U-TURN TOWARD THE SW. PLEASE SEE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH EXTENDS FROM 06N77W TO 07N90W TO A 1010 MB LOW 
PRES NEAR 09N98W TO 11N104W...THEN RESUMES W OF AMANDA FROM 
10N114W TO 07N120W TO A SECOND 1009 MB LOW PRES NEAR 09N128W TO 
04N135W. THE ITCZ AXIS CONTINUES FROM 04N135W TO BEYOND 05N140W. 
CLUSTER OF MODERATE TO STRONG CONVECTION FROM 02N TO 05N E OF 
81W TO THE COAST OF COLOMBIA. SCATTERED MODERATE ISOLATED STRONG 
ELSEWHERE FROM 03N TO 08N E OF 86W...FROM 07N TO 09N BETWEEN 
108W AND 115W AND FROM 05N TO 08N BETWEEN 125W AND 127W.

...DISCUSSION...     

STRONG 1039 MB SURFACE HIGH PRES IS LOCATED WELL NW OF THE 
FORECAST AREA NEAR 43N144W. THIS HIGH EXTENDS A RIDGE SE ACROSS 
THE WATERS THROUGH 30N127W TO 24N114W. A TIGHT PRES GRADIENT 
EXISTS ON THE E-SE SIDE OF THE RIDGE WITH GALE FORCE WINDS NOW 
BLOWING NEAR THE NORTHERN AND CENTRAL COAST OF CALIFORNIA. THIS 
SYSTEM IS ALSO PRODUCING FRESH TO STRONG WINDS ACROSS THE N 
WATERS MAINLY N OF 28N BETWEEN 125W AND 130W AND N OF 23N W OF 
130W. AN EARLIER SCATTEROMETER PASSES CONFIRMED THE PRESENCE OF 
THESE WINDS. THE HIGH IS FORECAST TO MOVE TO A POSITION NEAR 
42N142W BY 24 HOURS...AND NEAR 40N141W BY 48 HOURS WHILE 
WEAKENING. AS A RESULT WINDS ARE FORECAST TO BE 20 KT OR LESS 
ACROSS THE N WATERS BY ABOUT 24 HOURS. HOWEVER...SEAS GENERATED 
BY THESE STRONG WINDS WILL CONTINUE TO SPREAD ACROSS THE 
FORECAST WATERS AS NORTHERLY SWELL. THIS SWELL EVENT WILL 
COMBINE WITH LONG PERIOD SOUTHERLY SWELL TO BUILD SEAS UP TO 10-
11 FT...PARTICULARLY N OF 28N BETWEEN 121W AND 126W BY EARLY THU 
MORNING.

WEAK 1008 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR  
09N128W. ASSOCIATED WINDS ARE CURRENTLY 10-15 KT WITH SEAS OF 6-
7 FT AND LITTLE CHANGE IN THESE CONDITIONS ARE FORECAST THROUGH 
THE NEXT 48 HOURS AS THE LOW MOVES WESTWARD AT 5-10 KT.

WINDS OF 20 KT AND SEAS TO 8 FT E OF 89W WERE OBSERVED ACROSS 
THE GULF OF PAPAGAYO EARLY THIS MORNING. MARINE GUIDANCE 
SUGGESTS WINDS OF 10-15 KT AND SEAS OF 6-7 FT BY EARLY THU 
MORNING. 
 
CROSS EQUATORIAL SW SWELL WILL REACH THE FAR SOUTH-CENTRAL 
WATERS BY THU AFTERNOON...THEN SPREAD NORTHWARD COVERING THE 
WATERS S OF A LINE FROM 3.4S110W TO 01N104W TO 00N94W TO 3.4S84W 
BY EARLY FRI MORNING.
 
$$
GR