000
AXPZ20 KNHC 190929
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN FEB 19 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 FROM 00N92W TO 05N111W TO LOW PRES NEAR 04N121W 
1010 MB TO 02N128W. ITCZ FROM 02N128W TO BEYOND 01N140W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WITHIN 140 NM S 
OF TROUGH BETWEEN 110W AND 115W. SIMILAR CONVECTION IS NOTED 
NEAR 03N119W AND WITHIN 50 NM S OF TROUGH BETWEEN 121W AND 124W.

...DISCUSSION...

A DISSIPATING COLD FRONT JUST NORTH OF THE DISCUSSION AREA FROM 
SOUTHERN CALIFORNIA TO 31N118W WILL BRING AN INCREASE IN WINDS 
AND SEAS ACROSS THE N WATERS MAINLY N OF 27N. EXPECT NLY WINDS 
OF 20 KT AND BUILDING SEAS TO AROUND 15 FT IN NW SWELL IN THE 
WAKE OF THE DISSIPATING FRONT. A LONG WAVE TROUGH EXTENDING FROM 
THE NORTHERN ROCKIES TO 31N120W TO BEYOND 31N140W SUPPORTS THIS 
FRONT.

FURTHER SOUTH...A BROAD AND NEGATIVELY TILTED MID/UPPER TROUGH 
EXTENDS FROM 18N124W TO 05N118W...TO THE WEST OF A AN UPPER 
RIDGE CENTERED OVER NORTHERN CENTRAL AMERICA. ABUNDANT MID/UPPER 
LEVEL MOISTURE IS NOTED BETWEEN THESE FEATURES. THIS TROUGH IS 
SUPPORTING A PERSISTENT 1010 MB SURFACE LOW ALONG THE MONSOON 
TROUGH NEAR 04N121W AS WELL AS CLUSTERS OF MODERATE CONVECTION 
SW OF THE LOW PRES...SOUTH OF THE MONSOON TROUGH...AND FROM 10N 
TO 12N BETWEEN 107W TO 111W.  

SOMEWHAT TIGHT PRES GRADIENT BETWEEN THE SURFACE LOW AND STRONG 
1034 MB HIGH PRES CENTERED NEAR 33N144W IS MAINTAINING FRESH TO 
STRONG NE TO E FLOW FROM 05N TO 27N W OF 115W. SCATTEROMETER 
DATA CONFIRMED THE PRESENCE OF THESE WINDS. MEANWHILE...NW SWELL 
WITH 13 TO 15 SECOND PERIODS AND HEIGHTS OF 8 TO 12 FT CONTINUE 
TO PUSH INTO THE AREA AND MIX WITH FRESH NE SWELL ASSOCIATED 
WITH THE PERSISTING TRADE WIND FLOW. 

...GAP WINDS...

GULF OF TEHUANTEPEC...EXPECT INCREASING WINDS AND SEAS ACROSS 
THE GULF OF TEHUANTEPEC THIS AFTERNOON AS A STRONG...BUT FAST 
MOVING...COLD FRONT MOVES THROUGH CHIVELA PASS. THE NORTHERLY 
WINDS THROUGH THE PASS INTO THE GULF OF TEHUANTEPEC ARE FORECAST 
TO BRIEFLY REACH GALE FORCE TONIGHT BEFORE DIMINISHING BELOW 
GALE BY MON MORNING. A GALE WARNING REMAINS IN EFFECT FOR THAT 
AREA.

GULF OF PAPAGAYO...NE TO E WINDS WILL CONTINUE TO PULSE TO 20 KT 
THROUGH THE GULF OF PAPAGAYO THROUGH MON MORNING. THE STRONGEST 
WINDS WILL OCCUR DURING THE EARLY MORNING HOURS WITH THE AID OF 
DRAINAGE FLOW. THE TRADE WIND FLOW OVER THE SW CARIBBEAN MAY 
START TO INCREASE BY MON NIGHT...ALLOWING FOR THE START OF MORE 
SUSTAINED GAP WIND FLOW THROUGH PAPAGAYO MON NIGHT THROUGH TUE 
MORNING.

GULF OF PANAMA...EXPECT A MODEST INCREASE TO 20 KT IN THE 
NORTHERLY FLOW ACROSS THE GULF OF PANAMA STARTING MON NIGHT DUE 
TO STRONGER TRADE WIND FLOW OVER THE SW CARIBBEAN.
 
$$
GR/EC