000
AXPZ20 KNHC 300932
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI NOV 30 2012

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 
0900 UTC.

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

MONSOON TROUGH EXTENDS FROM 09N84W TO 07N93W TO 08N98W TO 
06N106W WHERE IT TRANSITIONS TO THE ITCZ TO 07N120W TO 06N130W 
TO 07N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED FROM 08N TO 10N BETWEEN 87W AND 92W AND WITHIN 90 NM S OF 
TROUGH BETWEEN 103W AND 105W.

...DISCUSSION...

ALOFT...A SHORT-WAVE TROUGH EXTENDS FROM 25N130W TO BEYOND 
15N140W. AN ANTICYCLONIC CIRCULATION IS CENTERED NEAR 15N114W 
WITH A RIDGE EXTENDING N ACROSS BAJA CALIFORNIA AND NW MEXICO 
INTO THE SW CONUS. STRONG W TO SW FLOW BETWEEN THE SHORT-WAVE 
TROUGH AND THE RIDGE IS TRANSPORTING ABUNDANT MID TO UPPER LEVEL 
MOISTURE FROM THE TROPICS ACROSS SOUTHERN BAJA CALIFORNIA INTO 
CENTRAL MEXICO. BROAD MID/UPPER RIDGING STRETCHES FROM THE 
NORTHERN PORTION OF S AMERICA WESTWARD ACROSS THE EPAC WATERS TO 
NEAR 106W. UPPER DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS 
HELPING TO INDUCE CONVECTION ALONG THE MONSOON TROUGH...MAINLY 
FROM 08N TO 10N BETWEEN 87W AND 92W WHERE A PAIR OF CLUSTERS OF 
MODERATE TO ISOLATED STRONG CONVECTION ARE SEEN.  

AT THE SURFACE...A VERY LARGE CYCLONIC CIRCULATION IS SPINNING 
WELL N OF THE AREA. THE CYCLONIC FLOW ASSOCIATED WITH IT REACHES 
THE N WATERS ESPECIALLY N OF 28N W OF 130W PRODUCING FRESH TO 
STRONG WLY WINDS. SCATTEROMETER DATA CONFIRMED THE PRESENCE OF 
THESE WINDS. THE ATTENDANT COLD FRONT CROSSES NEAR 31N140W BUT 
IS FORECAST TO REMAIN N OF AREA. A 1022 MB HIGH PRES SITUATED 
NEAR 28N120W HAS A RIDGE EXTENDING TO NEAR 18N110W. ANOTHER 1020 
MB HIGH PRES IS NEAR 23N139W. S OF THE RIDGE...MODERATE TO FRESH 
TRADE WINDS ARE NOTED PER THE MOST RECENT ASCAT PASSES. BETWEEN 
THE HIGH PRES SYSTEMS...THERE IS A TROUGH...ANALYZED ON THE 0600 
UTC SURFACE MAP FROM 24N113W TO 18N136W. AN EARLIER WINDSAT PASS 
AND THE 0556 UTC ASCAT PASS SHOWED CLEARLY THE WIND SHIFT 
ASSOCIATED WITH THIS TROUGH AND MAINLY LIGHT WINDS ON EITHER 
SIDE OF THE TROUGH AXIS. THE RIDGE IS FORECAST TO STRENGTHEN 
SLIGHTLY DURING THE NEXT 24 HRS...THEN WEAKEN INTO 48 HRS. 

LONG PERIOD NW SWELLS...GENERATED BY THE AFOREMENTIONED VERY 
LARGE CYCLONIC CIRCULATION...ARE INVADED THE REGIONAL WATERS 
RAISING SEAS TO 19 FT IN THE FAR NW PORTION OF THE FORECAST 
REGION. THIS SWELL EVENT WILL CONTINUE TO SPREAD E AND SE 
COVERING MOST OF THE WATERS W OF 110W LATER TODAY. SEA HEIGHTS 
WILL GRADUALLY SUBSIDE DURING THE WEEKEND BUT WILL REMAIN  
HIGHER THAN 8 FT ACROSS A LARGE AREA.    

GAP WINDS...
BASED ON SCATTEROMETER DATA...WINDS HAVE DIMINISHED TO 20 TO 25 
KT ACROSS THE GULF OF TEHUANTEPEC. HOWEVER...MARINE GUIDANCE 
SUGGESTS WINDS OF 20-30 KT ACROSS THIS GULF PARTICULARLY BETWEEN 
0600-1200 UTC WHEN WINDS ARE GREATEST WITH THE AID OF THE 
DRAINAGE FLOW. LITTLE CHANGE IS EXPECTED THROUGH THE WEEKEND 
WITH SEAS OF 8 TO 9 FT.

EXPECT WINDS OF 20 KT TO PULSE ACROSS THE GULF OF PAPAGAYO 
DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE 
OF THE NOCTURNAL DRAINAGE FLOW .

$$
GR