000
AXPZ20 KNHC 210937
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE FEB 21 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 AXIS ANALYZED FROM 05N77W TO 05N90W. ITCZ 05N90W 
TO 02N100W TO LOW PRES NEAR 04N120W 1012 MB TO 04N130W TO 
00N140W. SCATTERED MODERATE CONVECTION FROM 05N TO 07N BETWEEN 
116W AND 120W. SIMILAR CONVECTION IS NOTED WITHIN 90 NM NW OF 
LINE 11N112W TO 09N115W.

...DISCUSSION...

BROAD UPPER TROUGHING PREVAILS ACROSS N PORTIONS OF THE FORECAST 
AREA EXTENDING FROM NORTHERN BAJA CALIFORNIA TO 25N126W TO 
BEYOND 27N140W. A 50-70 KT UPPER JET CURRENTLY LIES S OF THE 
TROUGH AXIS. THIS JET IS TRANSPORTING MID AND HIGH LEVEL 
MOISTURE NORTHEASTWARD INTO MEXICO...ROUGHLY FROM JALISCO TO 
TAMAULIPAS.

A PERSISTENT NEGATIVE TILT UPPER TROUGH EXTENDS FROM NEAR 
14N120W TO 05N115W. THIS TROUGH IS LOCATED TO THE W OF A STRONG 
BLOCKING UPPER RIDGE THAT DOMINATES THE WRN CARIBBEAN AND MUCH 
OF THE GULF OF MEXICO. THIS RIDGE IS HELPING TO MAINTAIN THE 
QUASISTATIONARY LOCATION OF THIS UPPER TROUGH. UPPER DIFFLUENCE 
AHEAD OF THIS TROUGH IS HELPING TO INDUCE THE MODERATE 
CONVECTION NOTED FROM 05N TO 11N BETWEEN 112W AND 120W. 

AT THE SURFACE...A 1035 MB HIGH CENTERED NEAR 33N142W EXTENDS A 
RIDGE SE OVER FORECAST WATERS TO NEAR 18N110W. THE PRESSURE 
GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE ALONG THE SIERRA 
MADRES OF MEXICO IS PRODUCING AN AREA OF FRESH NWLY WINDS JUST 
OFFSHORE OF BAJA CALIFORNIA BUT MAINLY N OF 25N E OF 117W... 
WHERE SEAS ARE RUNNING 9-12 FT IN NW SWELL. TO THE SOUTH OF THIS 
STRONG HIGH PRES...FRESH TO STRONG TRADE WINDS COVER THE AREA 
FROM 05N TO 26N W OF 125W AND FROM 07N TO 20N BETWEEN 115W AND 
125W WITH SEAS IN THE 9 TO 13 FT RANGE IN MIXED NE AND NW SWELL. 
EXPECT THE SURFACE HIGH TO SHIFT NE OVER THE NEXT 48 HOURS AND 
REDUCE THE GRADIENT WINDS OFF BAJA CALIFORNIA...AND SHIFT THE 
AREA OF FRESH NE TRADES WWD OF 125W. 

MEANWHILE SUCCESSIVE PULSES OF NW SWELL WITH INITIAL PERIODS OF 
15-18 SECONDS WILL CONTINUE TO MIX WITH FRESH NE WIND SWELL OVER 
THE AREA W OF 110W.

...GAP WINDS...

GULF OF PAPAGAYO...THE PRES GRADIENT BETWEEN RIDGING IN THE NE 
GULF OF MEXICO AND TROUGHING TO THE S OF THE GULF OF PAPAGAYO IS 
FORCING FRESH NE WINDS HERE. WINDS WILL INCREASE TO STRONG IN 
THE EARLY MORNING HOURS WITH THE AID OF LOCAL DRAINAGE FLOW. 

GULF OF PANAMA...STRENGTHENING FLOW FROM THE CARIBBEAN WILL PUSH 
ACROSS THE ISTHMUS OF PANAMA AND INTO THE GULF OF PANAMA THROUGH 
WED. EXPECT WINDS OF 20 TO 25 KT...PARTICULARLY IN THE EARLY 
MORNING HOURS WITH SEAS LESS THAN 8 FT.

LOOKING AHEAD...THE NEXT GULF OF TEHUANTEPEC GAP WIND EVENT IS 
FORECAST TO OCCUR DURING THE UPCOMING WEEKEND AS THE NEXT COLD 
FRONT MOVES ACROSS THE WESTERN GULF OF MEXICO.  

$$
GR