000
AXPZ20 KNHC 171555
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN NOV 17 2013

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.

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

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 06N105W TO 13N120W. 
THE ITCZ EXTENDS FROM 13N140W. SCATTERED MODERATE CONVECTION 
WITHIN 50 NM N OF ITCZ AXIS BETWEEN 125W AND 132W.
 
...DISCUSSION... 

A CUTOFF UPPER CYCLONE IS CENTERED OFF THE COAST OF BAJA 
CALIFORNIA NORTE NEAR 29N119W...IN PHASE WITH A STATIONARY UPPER 
TROUGH EXTENDING SW TO 06N140W. THE UPPER CYCLONE IS SUPPORTING 
SPORADIC SHOWERS AND THUNDERSTORMS FROM 16N TO 20N BETWEEN 115W 
AND 120W. FARTHER WEST...A DEEPENING SHORT WAVE TROUGH IS 
DIGGING INTO THE DISCUSSION AREA ALONG 130W N OF 20N. GLOBAL 
MODELS SHOW THIS FEATURE CUTTING OFF INTO AN UPPER CYCLONE NEAR 
17N138W BY LATE MON/EARLY TUE...AS THE UPPER FEATURE NEAR 
29N119W DISSIPATES. 

THE EASTWARD PUSH OF THE UPPER TROUGH THROUGH 135W IS WEAKENING 
THE 1020 MB SURFACE HIGH NOW CENTERED NEAR 33N137W...WHICH IN 
TURN HAS ALLOWED TRADE WIND FLOW BETWEEN 10N AND 25N W OF 130W 
TO DIMINISH CONSIDERABLE SINCE YESTERDAY AS WELL NORTHERLY FLOW 
BETWEEN THE HIGH PRES AND THE COAST N OF 25N E OF 120W. 
ALTIMETER DATA SUPPORTS WW3 INITIALIZATIONS INDICATING POCKETS OF 
SEAS 7 TO 8 FT IN LINGERING N TO NE SWELL N OF 15N W OF 
120W...BUT THIS WILL SUBSIDE THROUGH THE REST OF TODAY. 

THROUGH EARLY NEXT WEEK...THE SURFACE RIDGE BEGINS TO BUILD 
AGAIN N OF 20N AS UPPER CYCLONE CUTS OFF AND WEAKENS NEAR 
17N138W AND THE UPPER PATTERN N OF 25N BECOMES MORE ZONAL. THIS 
WILL ALLOW TRADE WIND FLOW TO INCREASE IN THE DEEP TROPICS W OF 
125W MON INTO TUE...ALONG WITH FRESH NW TO N WINDS ALONG THE 
BAJA COAST AND GULF OF CALIFORNIA ON THE EAST SIDE OF THE HIGH.

OFF THE COAST OF COLOMBIA...SHIP AND SCATTEROMETER DATA INDICATE 
THE SW FLOW INTO THE MONSOON TROUGH OVER PANAMA IS STARTING TO 
INCREASE. GFS AND ECMWF GUIDANCE HAS BEEN INDICATED THIS OVER 
THE PAST SEVERAL RUNS. CONVERGENCE OF THESE LOWER LEVEL WINDS 
WITH MORNING DRAINAGE FLOW IS SUPPORTING CLUSTERS OF CONVECTION 
FROM 04N TO 07N E OF 80W. 

$$
CHRISTENSEN