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Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 192153
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT APR 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE EPAC MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT 
03N77W TO 06N88W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION 
TO AN ITCZ AXIS. THE ITCZ TURNS SW FROM 06N88W TO 04N110W... 
THEN WNW TO 05N123W...THEN WSW TO BEYOND 04N140W. 

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG 
THE MONSOON TROUGH AND ITCZ WITHIN 150 NM EITHER SIDE OF LINES 
FROM 03N77W TO 05N110W AND FROM 05N116W TO 09N127W. SIMILAR 
CONVECTION IS NOTED ALONG A LOW TO MID LEVEL TROUGH WITHIN 90 NM 
EITHER SIDE OF A LINE FROM 15N108W TO 10N120W.

...DISCUSSION...                                                

AN UPPER CYCLONE IS OVER SOUTHERN ARIZONA WITH A MID TO UPPER 
TROUGH EXTENDING SW TO A BASE NEAR 13N127W. A 360 NM WIDE BAND 
OF UPPER DEBRIS MOISTURE CONTINUES E OF THIS TROUGH AXIS FROM 
THE TROPICS AT 13N120W TO ACROSS THE PACIFIC COAST OF MEXICO AT 
22N105W...THEN TURNS N ACROSS NE MEXICO EVENTUALLY FANNING OUT 
OVER CENTRAL TEXAS. ANOTHER BAND OVER UPPER MOISTURE IS 
STREAMING E ACROSS THE NORTHERN PORTION OF THE DISCUSSION AREA 
WITHIN 150 NM OF A LINE FROM 31N140W TO 31N124W TO ACROSS 
SOUTHERN CALIFORNIA. OTHERWISE DRY UPPER AIR IS NOTED ACROSS THE 
DISCUSSION AREA W OF THE UPPER TROUGH AXIS.

AN E TO W UPPER RIDGE CONTINUES ACROSS THE DEEP TROPICS ALONG  
ABOUT 05N W OF 105W AND IS SUPPORTING THE PREVIOUSLY DESCRIBED 
ITCZ CONVECTION. SOME OF THE RESULTANT DEBRIS MOISTURE IS 
ADVECTED NE INTO THE TROPICAL MOISTURE PLUME ALREADY MENTIONED. 

ANOTHER E TO W UPPER RIDGE EXTENDS W OFF THE COAST OF COLOMBIA  
ALONG 07N TO A CREST NEAR 07N103W. WEAK DIFFLUENCE ALONG THIS 
RIDGE IS SUPPORTING THE PREVIOUSLY DESCRIBED CONVECTION ALONG 
THE MONSOON TROUGH AND ITCZ TO THE E OF 103W. DEBRIS MOISTURE 
FROM EARLIER ITCZ CONVECTION IS STREAMING NE ACROSS CENTRAL 
AMERICA AND THE CENTRAL CARIBBEAN.

A SURFACE RIDGE EXTENDS FROM 31N140W TO NEAR 10N110W. NE TRADES 
ARE ENHANCED TO 15-20 KT BETWEEN THE RIDGE AND 07N TO THE W OF 
125W...WITH SEAS OF 6-8 FT IN MIXED LONG PERIOD NW AND LONG 
PERIOD CROSS-EQUATORIAL SE SWELL. THIS AFFECTED AREA S OF THE 
RIDGE WILL PERSIST THROUGH THE WEEKEND. NW 10-15 KT WINDS WILL 
CONTINUE THROUGH SUN NIGHT TO NE OF THE RIDGE ALONG THE PACIFIC 
COAST OF THE BAJA CALIFORNIA PENINSULA WITH SEAS OF 4-5 FT. A 
NEW BATCH OF NW SWELL WILL ARRIVE OVER THE FAR NW PORTION NEAR  
30N140W TONIGHT...AND CONTINUE TO PROPAGATE E REACHING THE NW 
COAST OF THE BAJA PENINSULA IN THE FORM OF COMBINED SEAS OF 6-9 
FT ON MON. SEAS OF 8-9 FT WILL GRADUALLY SUBSIDE ACROSS THE 
DISCUSSION WATERS N OF 20N BETWEEN 112W-135W THROUGH LATE MON. 
THE PRESSURE GRADIENT WILL TIGHTEN ON TUE AND TUE NIGHT WITH NW 
WINDS INCREASING TO 20-25 KT ACROSS THE WATERS N OF 25N E OF 
122W TO BAJA PENINSULA ON WED.  

NORTHERLY FLOW HAS DIMINISHED TO 20-25 KT IN AND JUST DOWNSTREAM 
OF THE GULF OF TEHUANTEPEC. LITTLE CHANGE EXPECTED THROUGH SUN 
AFTERNOON WHEN THE GRADIENT QUICKLY RELAXES SUPPORTING NOCTURNAL 
MAXIMUM DRAINAGE OF 10-15 KT EACH NIGHT FROM SUN NIGHT THROUGH 
TUE NIGHT. ONLY LIGHT NORTHERLY WINDS EXPECTED ON WED NIGHT AND 
THU NIGHT.

$$
NELSON