000
AXPZ20 KNHC 151519
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN JAN 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1330 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 09N83W TO 05N96W. 
THE ITCZ AXIS EXTENDS FROM 05N96W TO 07N105W TO 05N117W TO 
08N135W TO 07N140W. SCATTERED MODERATE CONVECTION LIES WITHIN 
210 NM S OF THE AXIS E OF 80W AS WELL AS WITHIN 150 NM N OF THE 
AXIS W OF 136W.

...DISCUSSION...
AN UPPER LOW N OF THE AREA NEAR 33N125W IS MOVING NE TOWARD THE 
LEADING EDGE OF A DEEP LAYER TROUGH MAKING ITS WAY THROUGH THE 
WESTERN U.S. A SOUTHWESTERLY JET WITH TROPICAL ORIGINS IS 
TRANSPORTING MOISTURE S AND E OF THE LOW...WITH SCATTERED 
SHOWERS PRIMARILY FOUND WITHIN 120 NM EITHER SIDE OF LINE FROM 
32N115W TO 22N123W. THE DEEP LAYER TROUGH WILL OVERTAKE THE LOW 
LATER TODAY...BUT THE LOW IS EXPECTED TO LEAVE BEHIND SOME 
ENERGY THAT WILL AMPLIFY THE TROUGHING OVER NE WATERS...KEEPING 
THE SUBTROPICAL RIDGE SOMEWHAT WEAK OVER THAT AREA AND 
PREVENTING WINDS FROM INCREASING BEYOND A MODERATE BREEZE. NW TO 
N WINDS BEHIND THE COLD FRONT ASSOCIATED WITH THE DEEP LAYER 
TROUGH N OF THE AREA ARE GENERATING SWELL THAT WILL ALLOW SEAS 
TO BUILD TO 8-10 FEET AS IT MOVES INTO THE FORECAST AREA 
BEGINNING EARLY MON. THE COLD FRONT IS EXPECTED TO DISSIPATE AS 
IT REACHES THE FORECAST AREA MON.

WHILE RIDGING WILL REMAIN WEAKER OVER NE WATERS...IT WILL BUILD 
AT THE SURFACE OVER WESTERN WATERS BEHIND THE COLD FRONT. THIS 
WILL INCREASE THE PRES GRADIENT BETWEEN THE ITCZ AND THE 
SUBTROPICAL RIDGE WHICH IS EXPECTED TO BUILD ALONG 135W SUN AND 
MON BEFORE SHIFTING E TO 125W EARLY TUE. FRESH TRADE WINDS ARE 
CURRENTLY CONFINED TO A SMALL STRIP N OF THE ITCZ W OF 
125W...BUT THEY ARE EXPECTED TO EXPAND NORTHWARD MON BEFORE 
INCREASING IN STRENGTH AND STRETCHING EASTWARD THROUGH TUE 
MORNING IN RESPONSE TO THE CHANGES IN THE SUBTROPICAL RIDGE.

GAP WINDS...

GULF OF TEHUANTEPEC...1031 MB HIGH PRES OVER THE N CENTRAL GULF 
OF MEXICO SUN MORNING IS FORECAST TO MIGRATE NORTHEASTWARD OFF 
THE NORTH CAROLINA COAST BY MON AFTERNOON. THIS WILL SHIFT WINDS 
IN THE SW GULF OF MEXICO TO THE SE AND CUT OFF THE NORTHERLY 
FLOW THAT IS CURRENTLY IN PLACE AND FUNNELING THROUGH THE 
CHIVELA PASS INDUCING GALE FORCE WINDS IN THE GULF OF 
TEHUANTEPEC. THE GALE WARNING IS IN EFFECT THROUGH MON MORNING. 

GULF OF PAPAGAYO...THE HIGH PRES OVER THE N CENTRAL GULF OF 
MEXICO DRIVING THE GALE IN THE GULF OF TEHUANTEPEC WILL ALSO 
KEEP WINDS FRESH TO STRONG DOWNWIND OF THE GULF OF PAPAGAYO. AS 
THIS HIGH SHIFTS NE THROUGH MON...THE PRES GRADIENT WILL 
INCREASE OVER THE GULF OF PAPAGAYO ALLOWING FRESH TO STRONG 
WINDS TO SPREAD AS FAR WEST AS 96W BY MON MORNING. THESE WINDS 
SHOULD CONTINUE INTO TUE MORNING AND NE SWELL IS EXPECTED TO 
RAISE SIGNIFICANT WAVE HEIGHTS TO 9 FT BY THAT TIME AS FAR 
DOWNWIND OF PAPAGAYO AS 110W.

$$
SCHAUER