000
AXPZ20 KNHC 090924
TWDEP 

TWDEP 

TROPICAL WEATHER DISCUSSION                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC WED APR 09 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0830 UTC. 

...SPECIAL FEATURES...
       
GULF OF TEHUANTEPEC STORM WARNING

A 1027 MB HIGH OVER THE SW GULF OF MEXICO HAS TIGHTENED THE 
SURFACE PRESSURE GRADIENT OVER THE ISTHMUS OF TEHUANTEPEC. THIS 
TOGETHER WITH THE ADDED COMPONENT OF NOCTURNAL DRAINAGE FLOW HAS 
PRODUCED STORM FORCE WINDS OVER THE GULF OF TEHUANTEPEC. SEAS 
ARE PRESENTLY 14 TO 23 FT N OF 12.5N. STORM FORCE WINDS ARE 
EXPECTED TO LAST FOR 12 HOURS AND ARE FORECAST TO DIMINISH TO 
STRONG GALE FORCE WED AFTERNOON...THEN BELOW GALE FORCE THU 
AFTERNOON. WINDS AND SEAS WILL FINALLY DECREASE BELOW ADVISORY 
CRITERIA FRIDAY AFTERNOON.

GULF OF PAPAGAYO GALE WARNING

THE COLD FRONT RESPONSIBLE FOR THE STORM EVENT OVER THE GULF OF 
TEHUANTEPEC WILL CONTINUE TO SHIFT EASTWARD AND HELP FOR A RARE 
GALE FORCE GAP WIND EVENT OVER THE GULF OF PAPAGAYO. WINDS WILL 
INCREASE TO 25 KT BY WED MORNING. WINDS WILL THEN FURTHER 
INCREASE TO NEAR GALE FORCE LATE WED NIGHT...THEN BRIEFLY REACH 
GALE FORCE EARLY THU MORNING BEFORE DIMINISHING BELOW GALE FORCE 
THU AFTERNOON.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
MONSOON TROUGH EXTENDS FROM 07N78W TO 06N88W. ITCZ EXTENDS FROM 
06N88W TO 05N100W TO 04N110W TO 07N120W TO 04N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS FROM 07N TO 10N BETWEEN 
117W AND 125W. SCATTERED MODERATE CONVECTION IS FROM 02N TO 05N 
BETWEEN 131W AND 136W. 

...DISCUSSION...                                                

ALOFT...AN UPPER LEVEL TROUGH IS OVER THE NW CORNER N OF 26N W 
OF 136W. A LARGE UPPER LEVEL RIDGE IS ELSEWHERE OVER THE WESTERN 
AREA W OF 115W WITH RIDGE AXIS FROM 06N130W TO 30N122W. FURTHER 
E...A LARGE UPPER LEVEL TROUGH IS BETWEEN 100W AND 115W. AN 
UPPER LEVEL RIDGE IS E OF 100W WITH AXIS ALONG 90W. A GOOD 
AMOUNT OF UPPER LEVEL MOISTURE AND BROKEN HIGH CLOUDS ARE S OF 
COSTA RICA AND PANAMA FROM THE EQUATOR TO 10N E OF 90W DUE TO 
UPPER LEVEL DIFFLUENCE. 
 
AT THE SURFACE...A SLOW MOVING COLD FRONT IS OVER THE NW CORNER 
FROM 30N139W TO 28N139W TO BEYOND 25N140W. THIS FRONT HAS S TO 
SW WINDS 20 TO 25 KT WITHIN 120 NM E OF FRONT AND WINDS 20 KT OR 
LESS W OF FRONT. SEAS TO 9 FT IN NW SWELL ARE ALONG THE FRONT. 
WEAK SURFACE RIDGING IS N OF 15N BETWEEN 110W AND 133W. AN AREA 
OF FRESH TO STRONG TRADEWINDS LINGER FROM 05N TO 12N W OF 130W 
WITH SEAS TO 8 FT. ELSEWHERE...SOME 8 FT SW SWELL IS FROM 00N TO 
3S BETWEEN 110W AND 120W.   

$$ 
FORMOSA