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Eastern Pacific Tropical Discussion

Active Tropical Systems Basin Outlooks Satellite
Eastern Pacific Basin Tropical Discussion
 
933 
AXPZ20 KNHC 160235
TWDEP 

TROPICAL WEATHER DISCUSSION                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC WED APR 16 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. 

...SPECIAL FEATURE...

GULF OF TEHUANTEPEC STORM WARNING 

HIGH PRESSURE IN THE WAKE OF A GULF OF MEXICO COLD FRONT IS 
CURRENTLY SURGING THROUGH THE ISTHMUS OF TEHUANTEPEC INTO THE 
GULF OF TEHUANTEPEC AT MINIMAL STORM FORCE...AND EXPECTED TO 
PERSIST THROUGH LATE TONIGHT. GALE CONDITIONS WILL THEN QUICKLY 
DIMINISH THROUGHOUT WED MORNING WITH WINDS BELOW GALE ON WED 
AFTERNOON. THE RESULTANT N-NE SWELL WILL PROPAGATE SW MIXING 
WITH LONG-PERIOD CROSS EQUATORIAL SWELL. SEAS WILL FINALLY 
SUBSIDE BELOW 8 FT NEAR 06N105W LATE THU NIGHT. SOUTHERLY WINDS 
AT 5-15 KT ARE THEN EXPECTED EACH DAY...AND LATE NIGHT DRAINAGE 
FLOW OF 10-20 KT IS EXPECTED EACH NIGHT THROUGH MON NIGHT.       
   
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
THE EPAC MONSOON TROUGH EXTENDS W ACROSS SOUTHERN E PANAMA TO 
ACROSS THE GULF OF PANAMA CONTINUING W ACROSS SOUTHERN W PANAMA 
TO THE PACIFIC COAST OF PANAMA AT 08N77W TO 08N812W TO 05N99W 
WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ 
AXIS...WHICH IN TURN WIGGLES WESTWARD BETWEEN 04-05N TO BEYOND 
140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED 
ALONG THE MONSOON TROUGH WITHIN 150 NM EITHER SIDE OF A LINE 
FROM 08N80W TO 05N96W. SIMILAR CONVECTION IS NOTED OVER...AND
TO THE N OF THE ITCZ WITHIN 150 NM EITHER SIDE OF A LINE FROM 
07N120W TO 06N133W. 

...DISCUSSION...                                                

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 10N120W WITH AN 
UPPER RIDGE EXTENDING N TO BEYOND 34N127W. THE ENVELOPE OF 
ANTICYCLONIC FLOW DOMINATES THE DISCUSSION AREA N OF THE ITCZ TO 
THE W OF 112W. DENSE UPPER MOISTURE IS ADVECTED NE ALONG THE 
PERIPHERY OF THIS RIDGE...WITHIN 360 NM OF A LINE FROM 16N140W 
TO 28N116W...THEN SPILLS SE ACROSS THE BAJA CALIFORNIA PENINSULA 
AND THE GULF OF CALIFORNIA. UPPER DIFFLUENCE ALONG THE SOUTHERN 
PERIPHERY OF THE LARGE UPPER ANTICYCLONE IS ENHANCING THE  
CONVECTION ALONG THE ITCZ AS PREVIOUSLY MENTIONED. 

AN UPPER TROUGH IS ADVANCING E ACROSS THE SE CONUS AND CONTINUES 
SW ACROSS THE WESTERN GULF OF MEXICO AND CENTRAL MEXICO INTO AN 
UPPER CYCLONE OVER THE PACIFIC NEAR 12N105W WITH A TROUGH STILL 
CONTINUING SW TO A BASE AT 02N114W. THIS TROUGH SEPARATES THE 
BROAD ANTICYCLONIC FLOW ALREADY MENTIONED OVER THE NW PORTION 
FROM ANTICYCLONIC FLOW OVER THE DISCUSSION AREA TO THE S OF 17N 
E OF 96W. THE ASSOCIATED UPPER DIFFLUENCE IS SUPPORTING THE 
CONVECTION ALONG THE MONSOON TROUGH AS PREVIOUSLY DESCRIBED.

A SURFACE HIGH PRES RIDGE EXTENDS FROM 32N138W TO NEAR 19N114W. 
NE TRADES ARE ENHANCED TO 15-20 KT S OF THE RIDGE ACROSS THE 
PACIFIC WATERS FROM 06-19N BETWEEN 122-140W WITH SEAS OF 7-10 FT 
IN MIXED LONG PERIOD NW AND CROSS-EQUATORIAL SE SWELL. THIS 
AFFECTED AREA S OF THE RIDGE WILL SHRINK WESTWARD OVER THE NEXT 
FEW DAYS AS NE WINDS OF 15-20 KT FORM NE OF THE RIDGE AND SPREAD 
S INTO THE AREA N OF 27N BETWEEN 118-127W ON THU. 
 
$$ 
NELSON