000
AXPZ20 KNHC 220231
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0215 UTC. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
THE MONSOON TROUGH IS DIFFICULT TO LOCATE. SCATTEROMETER WINDS 
INDICATE AN ITCZ FORMS FROM 05N96W TO 07N109W TO 06N117W TO 
06N135W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS MOVING 
OFF THE COAST OF COLOMBIA FROM 02-09N...AND IS DECAYING WITHIN 
120 NM EITHER SIDE OF A LINE FROM 04N83W TO 06N90W. SCATTERED 
MODERATE ISOLATED STRONG IS OBSERVED WELL N OF THE ITCZ WITHIN 
120 NM EITHER SIDE OF A LINE FROM 09N106W TO 11N114W TO 09N130W. 
ISOLATED MODERATE TO STRONG IS OBSERVED ELSEWHERE FROM 02N TO 
13N BETWEEN 105W TO 140W. 

...DISCUSSION...                                       

AN UPPER SHORTWAVE TROUGH HAS MOVED OVER THE NW PORTION OF THE 
DISCUSSION AREA WITH ITS MEAN AXIS FROM 32N127W TO 22N140W. THIS 
TROUGH IS PRECEDED BY A BAND OF UPPER MOISTURE N OF 26N WITHIN 
ABOUT 480 NM E OF THE TROUGH AXIS...AND IS CURRENTLY MOVING E 
ACROSS THE CALIFORNIA COAST TO THE N OF 32N. A SECOND UPPER 
TROUGH OVER THE CENTRAL CONUS CONTINUES SW ACROSS MEXICO AND THE 
SOUTHERN GULF CALIFORNIA TO A BASE OVER THE EPAC NEAR 16N107W. A 
300 NM WIDE BAND OF UPPER MOISTURE...ORIGINATING FROM ITCZ 
CONVECTION BETWEEN 110W-140W...CONTINUES E OF THE TROUGH AXIS 
FROM 12N109W TO ACROSS CENTRAL MEXICO AT 20N110W...THEN FANS OUT 
AS IT SPREADS NE ACROSS THE NE GULF OF MEXICO. 

AN UPPER ANTICYCLONE IS OVER THE DEEP TROPICS NEAR 08N131W WITH 
A SHORTWAVE RIDGE EXTENDING NE BETWEEN THE TWO UPPER TROUGHS... 
JUST DESCRIBED...TO A CREST AMPLIFYING N ACROSS CENTRAL ARIZONA. 
EXCEPT AS MENTIONED...THE UPPER LEVELS APPEAR VERY DRY TO THE N 
OF 17N WITHIN THE ANTICYCLONIC ENVELOPE. AN UPPER RIDGE EXTENDS 
E FROM THE TROPICAL ANTICYCLONE AT 08N131W TO A CREST NEAR 
07N107W AND CONTINUES TO ENHANCE CONVECTION ALONG THE WESTERN 
SEGMENT OF THE ITCZ AS PREVIOUSLY DESCRIBED.    

ANOTHER UPPER ANTICYCLONE IS CENTERED AT 08N98W WITH AN UPPER 
RIDGE EXTENDING NE ACROSS THE YUCATAN PENINSULA AND THE EASTERN 
GULF OF MEXICO TO A GENTLE CREST OVER SE GEORGIA. UPPER MOISTURE 
IS OBSERVED OVER THE W PERIPHERY OF THE RIDGE ORIGINATING FROM 
ITCZ CONVECTION BETWEEN 100-107W. 

A WEAK ILL-DEFINED UPPER TROUGH EXTENDS SW FROM OVER NICARAGUA 
TO A BASE OVER THE DEEP TROPICS AT 02N94W...AND EFFECTIVELY 
SEPARATES THE UPPER ANTICYCLONIC FLOW JUST DESCRIBED FROM THE 
FLOW ASSOCIATED WITH ANOTHER E TO W UPPER RIDGE EXTENDING W OFF 
THE COAST OF COLOMBIA ALONG 08N TO THE E OF 90W. WEAK DIFFLUENCE 
ALONG THIS EASTERN RIDGE IS SUPPORTING THE PREVIOUSLY DESCRIBED 
CONVECTION ALONG THE MONSOON TROUGH AND ITCZ TO THE E OF 90W. 
SOME OF THE DEBRIS MOISTURE FROM THIS CONVECTION IS ADVECTED NE 
ACROSS PANAMA...COSTA RICA AND THE SW CARIBBEAN...THE TURNS E 
ACROSS THE CENTRAL CARIBBEAN. DRY UPPER AIR IS SUPPRESSING 
CONVECTION OVER CENTRAL AMERICA FROM THE YUCATAN PENINSULA TO 
NICARAGUA...AS WELL AS THE EPAC TO THE N OF 08N BETWEEN 85-96W.

A WEAK COLD FRONT HAS MOVED INTO THE NW DISCUSSION WATERS FROM 
32N129W TO 27.5N140W. A SURFACE RIDGE IS ALREADY BRIDGING 
THROUGH THE WEAKENING FRONTAL BOUNDARY FROM NEAR 30N140W TO 
19N110W. NE TRADES AT 15-20 KT CONTINUE S OF THE RIDGE ACROSS 
THE WATERS FROM 08-22N W OF 125W...WITH SEAS OF 7-8 FT IN MIXED 
NE WIND WAVES...AND NOW REINFORCED LONG PERIOD NW SWELL STILL 
MIXING WITH LONG PERIOD CROSS-EQUATORIAL S SWELL. 

THE REINFORCING NW SWELL HAS REACHED THE NW COAST OF THE BAJA 
PENINSULA IN THE FORM OF COMBINED SEAS OF 6-10 FT...WITH THESE 
CONDITIONS EXPECTED TO SPREAD S ALONG THE BAJA PENINSULA N OF 
25N TONIGHT. THE NW SWELL WILL GRADUALLY SUBSIDE ACROSS THE 
DISCUSSION WATERS N OF ON TUE. HOWEVER...THE PRESSURE GRADIENT 
WILL TIGHTEN ON TUE NIGHT WITH NW WINDS INCREASING TO 20-25 KT 
ACROSS THE WATERS N OF 28N E OF 120W TO BAJA PENINSULA. THESE 
WINDS WILL DIMINISH AND THE SEAS WILL SUBSIDE ON THU. ATTENTION 
THEN TURNS TO THE S AS CROSS EQUATORIAL SOUTHERLY SWELL 
PROPAGATES N TO ALONG 25N ON FRI.    

$$
NELSON