000
AXPZ20 KNHC 050926
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JAN 5 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 06N77W TO 08N84W TO 05N89W. THE 
ITCZ CONTINUES FROM 05N89W TO 07N114W TO 06N140W. NO SIGNIFICANT 
CONVECTION ALONG THE CONVERGENCE ZONE.

...DISCUSSION...
A WEAKENING COLD FRONT IS SWEEPING PAST NORTHERN WATERS WITH WIND
SHIFT ALONG THE BOUNDARY. WEAK 1025 MB HIGH PRES AHEAD OF FRONT 
BUT UNUSUALLY STRONG OCEANIC HIGH IS BUILDING W OF THE FRONT... 
CENTERED NEAR 33N149W. THE STRONG HIGH WILL SHIFT EASTWARD ALONG 
32N THROUGH TUE AND ENHANCE TRADE WINDS SOUTH OF THE HIGH AS THE 
PRES GRADIENT N OF THE CONVERGENCE ZONE TIGHTENS CONSIDERABLY. 
EXPECT AREA OF FRESH TO STRONG NE WINDS N OF THE ITCZ EXPANDING 
TO COVER AN AREA FROM 08N TO 25N W OF 125W BY SUN. CURRENTLY...
SCATTEROMETER DATA SHOWS FRESH NE TRADES N OF THE ITCZ BETWEEN 
120W AND 135W. LARGE NW SWELL TRAILING BEHIND THE COLD FRONT IS 
APPROACHING THE NW CORNER OF THE DISCUSSION AREA WITH COMBINED 
SEAS TO 14-15 FT. 11-14 FT SEAS WILL SPREAD SOUTHEASTWARD ACROSS 
THE REGION THROUGH SUN. 

GAP WINDS...
ASCAT SCATTEROMETER PASS AT 0330 UTC SHOWED 25 KT MAXIMUM WINDS 
NEAR 15N95W...AND SURFACE WINDS ABOUT 5-10 KT LOWER THAN EXPECTED
FROM GFS MODEL BOUNDARY LAYER WIND FORECAST. SHIP OBSERVATIONS 
ALSO SHOW WINDS 20-25 KT IN THE AREA. BASED ON THESE DATA...THE 
GALE WARNING HAS BEEN DISCONTINUED FOR THE PRESENT TIME. COULD 
EXPECT TO SEE WINDS PEAK AT GREATER THAN 30 KT N OF 15N IN THE 
GULF OF TEHUANTEPEC AROUND SUNRISE THIS MORNING...BUT MODEL 
CONSENSUS DOES NOT SUPPORT GALE CONDITIONS UNTIL AROUND 00Z-06Z 
MON MORNING WHEN STRONG HIGH PRES BUILDS SOUTHWARD INTO THE SW 
GULF OF MEXICO. UNTIL THEN...A TROUGH OF LOW PRES IN THE SW GULF 
OF MEXICO WILL RELAX THE PRES GRADIENT ENOUGH TO SUPPORT STRONG 
TO NEAR-GALE WINDS AT TIMES INTO TEHUANTEPEC. NE SWELL GENERATED 
BY ENHANCED N-NE WINDS IN TEHUANTEPEC WILL SPREAD DOWNWIND FROM 
ITS SOURCE REGION TO 8N-13N BETWEEN 95W AND 105W.

20-25 KT WINDS WILL CONTINUE TO PULSE DIURNALLY...WITH HIGHEST 
WINDS IN THE EARLY MORNING HOURS...NEAR THE GULF OF PAPAGAYO 
FROM 10N TO 12N E OF 90W THROUGH SUN...WITH SEAS 8 FT OR LESS.

$$
MUNDELL