000
AXPZ20 KNHC 302204
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JAN 30 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 05N77W TO 
03N103W TO 08N124W TO 07N140W. SCATTERED MODERATE WITHIN 180 NM 
N OF AXIS FROM 116W TO 125W.

...DISCUSSION...
AT THE SURFACE...THE SEMI-PERMANENT NE PACIFIC HIGH IS CENTERED 
AT THE BORDER OF OUR AREA AT 31N 131W WITH A CENTRAL PRESSURE OF 
1028 MB.  THE GRADIENT BETWEEN THIS HIGH AND THE LOW PRESSURE OF 
THE ITCZ ARE GENERATING FRESH TO STRONG BREEZE NE TRADEWINDS.  
THESE ARE ANTICIPATED TO CHANGE LITTLE OVER THE NEXT TWO DAYS.  
IN THE NORTHWEST CORNER OF OUR AREA...SURFACE WINDS ARE 
ANTICIPATED TO BRIEFLY REACH 20 KT FROM THE SOUTH ON MONDAY 
AHEAD OF A COLD FRONT.  HOWEVER...FORCING OF THE COLD FRONT 
SHOULD MOVE NORTHEASTWARD...PREVENTING THE FRONT FROM REACHING 
140W.

AS A LOW PRESSURE SYSTEM DEVELOPS EAST OF THE ROCKIES ON 
MONDAY...THE SURFACE GRADIENT WILL BE ENHANCED ALONG BOTH SIDES 
OF BAJA CALIFORNIA.  NW WINDS WILL REACH 20 KT AROUND MONDAY 
MORNING AND DIMINISH BELOW THAT BY TUESDAY WEST OF BAJA AND 
CONTINUE THROUGH TUESDAY IN THE GULF OF CALIFORNIA.

A SURFACE TROUGH EMBEDDED IN THE ITCZ ALONG 124W BETWEEN 03N AND 
11N IS FORCING SOME DEEP CONVECTION AS MENTIONED IN THE ITCZ 
DISCUSSION.  THIS FEATURE IS ANTICIPATED TO MOVE TOWARD THE WEST 
OVER THE NEXT COUPLE OF DAYS...THOUGH FURTHER TROPICAL 
DEVELOPMENT IS UNLIKELY DUE TO STRONG VERTICAL SHEAR AND ONLY 
MODEST CONVECTIVE INSTABILITY.

NW SWELL BLANKETS NEARLY OUR ENTIRE AREA OF RESPONSIBILITY. ALL 
OF THIS LONG-PERIOD SWELL SHOULD REMAIN UNDER 12 FEET...WITH THE 
EXCEPTION OF N OF 27N W OF 138W WITH UP TO 14 FT SIGNIFICANT 
WAVE HEIGHTS.

GAP WINDS...A 1606 UTC ASCAT SCATTEROMETER PASS SHOWED THAT THE 
GULF OF PAPAGAYO GAP WINDS CONTINUED TODAY WITH NE TO E WINDS OF 
20 TO 25 KT.  THIS SHOULD WEAKEN SLIGHTLY...BUT 
CONTINUE...THROUGH TUESDAY.

THE GULF OF PANAMA GAP WINDS WERE ALSO ACTIVE TODAY AS OBSERVED 
BY AN EARLIER SCATTEROMETER PASS WITH N WINDS TO 20 KT.  THIS 
SHOULD FADE THIS EVENING BELOW OUR 20 KT CRITERIA.

THE NEXT STRONG GAP WIND EVENT...LIKELY A GULF OF 
TEHUANTEPEC...SHOULD COMMENCE WEDNESDAY NIGHT AND WILL LIKELY 
REACH AT LEAST GALE FORCE.

ALOFT...
A LARGE UPPER LEVEL TROUGH IS LOCATED ALONG 32N125W TO 14N140W.  
WHILE THIS IS NOT ASSOCIATED WITH ANY SIGNIFICANT SURFACE 
WEATHER AT THIS TIME...STRONG SOUTHWESTERLY WINDS ALOFT ARE 
INHIBITING ANY FURTHER DEVELOPMENT OF THE AFOREMENTIONED SURFACE 
TROUGH.

$$
LANDSEA