000
AXPZ20 KNHC 191002
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT FEB 19 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS ANALYZED FROM 00N120W TO 07N135W TO 07N140W. NO SIGNIFICANT 
CONVECTION NOTED.

...DISCUSSION...
SHARP MID TO UPPER TROUGH CONTINUES FROM NEAR 21N121W TO MID 
LEVEL CYCLONE NEAR 07N134W. NWLY FLOW DIVING INTO SW PORTIONS OF 
TROUGH PRODUCING MID TO UPPER CONVERGENCE AND ACTING TO DIMINISH 
CONVECTION ALONG ITCZ IN THIS AREA IN RECENT HOURS. A LARGE 
AMPLITUDE DEEP LAYER TROUGH EXTENDED FROM NE PAC S-SE TO 22N122W 
AND WAS ACTING TO REINFORCE PERSISTENT UPPER TROUGHING BETWEEN 
110W AND 140W. TROUGH SUPPORTS A REINFORCING FRONTAL BOUNDARY 
EXTENDING FROM 30N123W TO 24N133W. A LINGERING COLD FRONT AHEAD 
OF THIS NEW FRONT HAS SLOWED DURING PAST 12 HOURS AND EXTENDED 
FROM 30N119W TO 21N138W. NWLY WINDS AT OR NEAR GALE FORCE WERE 
SUGGESTED BY AFTERNOON AND EARLY EVENING SHIP REPORTS BEHIND THE 
NEWER REINFORCING FRONT AS IT SWEPT INTO NW PORTIONS OF THE 
AREA...BUT HAVE SINCE WEAKENED TO 20 TO 25 KT. LARGE NW  SWELL 
GENERATED BEHIND BOTH OF THESE FRONTAL BOUNDARIES DOMINATES MOST 
OF  THE AREA W OF 110W THIS MORNING...WITH WAVE HEIGHTS TO 15 FT 
BEHIND THE NEW FRONT. E OF THE TWO TROUGHS WAS A VERY FLAT UPPER 
RIDGE TO 100W...WHERE A MID LEVEL CYCLONE COULD BE SEEN IN WATER 
VAPOR IMAGERY NEAR 13N95W. THIS WAS THE W END OF AN ATLC TUTT 
AXIS...WITH CONVERGENCE ACROSS ALL BUT THE NE QUADRANT OF THE 
CYCLONE PRODUCING SUBSIDENCE. OTHERWISE...FAST ZONAL FLOW 
PREVAILED ACROSS THE TROPICAL EPAC...WITH A JET SEGMENT TO 60 KT 
DIVING UNDERNEATH THE PERSISTENT MID TO UPPER TROUGHING AND 
RIDING JUST N OF THE EQUATOR BETWEEN 125W AND 145W.  

THIS UPPER TROUGHING PATTERN WILL SHIFT SLIGHTLY E THROUGH THE 
WEEKEND AND BECOME MORE N TO S ALIGNED AND ALLOW FOR A STRONG 
SHORTWAVE AND ACCOMPANYING SURFACE LOW TO MOVE INTO N PORTIONS 
BY TUE. 

ELSEWHERE AT THE SURFACE...
THE REMNANTS OF EPAC HIGH PRES RIDGE REMAIN BETWEEN THE LEADING 
COLD FRONT AND THE BAJA CALIFORNIA PENINSULA...WITH A 1018 MB 
ANALYZED NEAR 21N117W. UPPER LEVEL SUPPORT WILL TRANSPORT THE 
TWO COLD FRONTS INLAND ACROSS SRN CALIFORNIA AND BAJA CALIFORNIA 
DURING THE NEXT 48 HOURS BEFORE BECOMING ILL DEFINED  AND 
DISSIPATING...WITH HIGH PRES SHIFTING E BEHIND THESE FRONTS AND 
BUILDING A RIDGE SE TO NEAR 14N105W BY MON MORNING. 
CURRENTLY..AS VERY SMALL AREA OF 20 KT NE TRADEWINDS EXISTS N OF 
THE ITCZ ACROSS SW PORTIONS OF THE AREA...BUT WILL  EXPAND 
GREATLY SUN NIGHT THROUGH MON AS THIS HIGH PRES BUILDS ACROSS 
THE AREA.  

GAP WINDS...
A SMALL PLUME OF NELY WINDS CONTINUES TO EXIT CENTRAL AMERICA 
THROUGH THE GULF OF PAPAGAYO AND WILL MAINTAINING FRESH WINDS 
SPILLING INTO THE E PAC FROM WESTERN CARIBBEAN THROUGH PERIOD. 

LOW PRES 1007 MB OVER N COLOMBIA WILL TIGHTEN THE GRADIENT OVER 
GULF OF PANAMA SUFFICIENTLY TO PRODUCE N WINDS TO NEAR 20 KT 
TODAY THAT WILL LIKELY PERSIST THROUGH MON. 

NELY WINDS IN THE SOUTHERN GULF OF MEXICO ARE EXPECTED TO SPILL 
ACROSS MEXICO AND BLOW THROUGH THE GULF OF TEHUANTEPEC AT 20 TO 
25 KT STARTING THIS MORNING...THEN DIMINISH TO LESS THAN 20 KT 
LATE SUN NIGHT.
 
$$
STRIPLING