000
AXPZ20 KNHC 101559
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU FEB 10 2011

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED FROM 07N78W TO 
04N90W TO 04N115W TO 08N120W TO 06N140W. SCATTERED MODERATE 
CONVECTION IS WITHIN 150 NM N OF THE AXIS BETWEEN 125W AND 133W.

...DISCUSSION...
ALOFT...AN AMPLIFIED UPPER LEVEL TROUGH AXIS EXTENDS FROM 
32N121W SW TO 20N140W...WITH A BASE NEAR 11N143W MOVING EASTWARD 
INTO THE FAR WESTERN FORECAST WATERS. THE SUBTROPICAL JET E OF 
THE TROUGH IS ADVECTING ABUNDANT MOISTURE ALOFT INTO THE 
SOUTHERN BAJA CALIFORNIA PENINSULA AND NW MEXICO WITH CORE 
SPEEDS NEAR 80 KT. THIS AMPLIFIED UPPER LEVEL PATTERN APPEARS 
TEMPORARY AS MODEL GUIDANCE SUGGESTS THE UPPER RIDGE TO THE W OF 
THIS TROUGH CURRENTLY EXTENDING NE FROM HAWAII TO NEAR 40N136W 
WILL ENCROACH UPON THE POSITIVELY TILTED UPPER TROUGH...PINCHING 
OFF AN ANTICYCLONE NEAR 34N130W LATE FRI AND ALLOWING THE TROUGH 
TO LEAVE BEHIND AN UPPER LOW NEAR 22N135W.

SURFACE...1031 MB HIGH PRES CENTERED NEAR 47N128W CONTINUES TO 
GRADUALLY MOVE TOWARD THE PACIFIC NW COAST WHILE THE ASSOCIATED 
RIDGE AXIS EXTENDS SOUTHWESTWARD TO EAST OF THE HAWAIIAN ISLANDS 
NEAR 20N147W. A NEW 1022 MB HIGH CENTER IS FORECAST TO DEVELOP 
NEAR 34N129W ALONG THE RIDGE AXIS WITHIN THE NEXT 24 HOURS. 
WHILE THE PRES GRADIENT HAS RELAXED GRADUALLY THROUGH THE 
MORNING HOURS...WINDS REMAIN BELOW 20 KT GENERALLY N OF 20N 
WHILE SEAS IN NW SWELL WILL CONTINUE TO SUBSIDE FROM 13 FT TO 
BELOW 8 FT BY EARLY SAT. S OF 20N HOWEVER...AN AREA OF 20 KT NE 
TRADES LIE FROM 07N TO 18N OVER THE FORECAST WATERS W OF 124W 
AND ARE EXPECTED TO BECOME GRADUALLY SMALLER IN AREAL COVERAGE 
BY EARLY SAT. BY SAT...THIS AREA OF FRESH TRADES IS EXPECTED TO 
LOCATE NW OF AN WESTWARD MOVING SURFACE TROUGH CURRENTLY 
EMBEDDED WITHIN THE ITCZ ALONG 124W.

GAP WINDS...
GULF OF TEHUANTEPEC...A COLD FRONT CONTINUES MOVING EASTWARD 
ACROSS THE SW GULF OF MEXICO WHICH HAS INITIATED 20 TO 30 KT N 
TO NE WINDS THROUGH THIS AFTERNOON...BECOMING GALE FORCE BY 
10/1800 UTC. THE INITIAL SURGE OF COLDER DENSE AIR IS EXPECTED 
TO TAPER OFF EARLY FRI. A SECONDARY SURGE OF COLD DRY AIR WILL 
BRING GALE FORCE WINDS TO THE TEHUANTEPEC REGION AGAIN BY EARLY 
SAT MORNING DUE TO AN INCREASED PRES GRADIENT OVER THE SW GULF 
OF MEXICO.

GULF OF PAPAGAYO...EASTERLY TRADE WINDS IN THE SOUTHWESTERN 
CARIBBEAN ARE SPILLING ACROSS THE MOUNTAINS OF COSTA RICA WITH 
WINDS TO 20 KT EXPECTED THROUGH THE REMAINDER OF THE PERIOD. THE 
STRONGEST WINDS ARE EXPECTED IN THE EARLY MORNING HOURS WHEN 
DRAINAGE FLOW IS AT A MAXIMUM.

GULF OF PANAMA...AS APPROACHING SURFACE TROUGHING TAKES 
RESIDENCE OVER THE NW CARIBBEAN SEA...THE PRESSURE GRADIENT IS 
EXPECTED TO BRIEFLY RELAX OVER THE SW CARIBBEAN. HOWEVER BY 
EARLY SAT...EASTERLY TRADES ARE EXPECTED TO SPREAD WESTWARD WITH 
DRAINAGE FLOW ACROSS THE ISTHMUS OF PANAMA INTO THE GULF 
REMAINING N OF 06N BETWEEN 78W AND 80W.

GULF OF CALIFORNIA...A TIGHT GRADIENT BETWEEN HIGH PRES OVER THE 
ROCKIES AND GREAT BASIN AND SURFACE TROUGHING OVER WESTERN 
MEXICO IS GENERATING NW WINDS WHICH ARE FUNNELING THROUGH THE 
GULF IN THE 20 TO 25 KT RANGE. SHIP PDAN NEAR 27N111W AT 0800Z 
REPORTED NW WINDS AT 23 KT. WINDS WILL DIMINISH TO 20 KT HERE 
TODAY AND THROUGH THE REMAINDER OF THE FORECAST PERIOD AS THE 
PRES GRADIENT GRADUALLY WEAKENS.

$$
HUFFMAN