000
AXPZ20 KNHC 201538
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 20 2010

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...
AXIS ANALYZED ALONG 02N79W TO 05N92W TO 04N101W TO 04N100W TO 
08N122W TO 07N140W. SCATTERED MODERATE CONVECTION WITHIN 90 NM N 
OF AXIS FROM 105W TO 111W. SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 60 NM N OF AND 100 NM S OF AXIS BETWEEN 111W 
AND 122W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
WITHIN 60 NM N AND 120 NM S OF AXIS BETWEEN 130W AND 136W. 

...DISCUSSION...
BROAD UPPER RIDGE ACROSS CENTRAL PACIFIC S OF THE HAWAIIAN 
ISLANDS EXTENDS E ALONG 14N TO 120W...WHILE A LARGE POLAR LOW SE 
OF THE ALEUTIANS CONTINUES TO PRODUCE AN UNUSUALLY STRONG AND 
BROAD W TO WNW JET FROM THE CENTRAL PACIFIC ESE TO OFFSHORE OF 
THE CALIFORNIA COAST NEAR 125W. CORE WIND SPEEDS IN THE UPPER 
JET WERE IN EXCESS OF 150 KT N OF 30N PER RECENT STLT DERIVED 
WINDS...WHILE A BRANCH OF 90-130 KT WNW WINDS WERE DETECTED FROM 
25N TO 30N MOVING INTO BAJA CALIFORNIA. A BROAD LONG WAVE TROUGH 
ACROSS THE GULF OF MEXICO EXTENDED FROM THE YUCATAN SW TO NEAR 
9N106W...THEN CONTINUED IN A NARROW TUTT LIKE FASHION 
WSW...CROSSING THE EQUATOR NEAR 140W. WEAK CYCLONIC TURNING AND 
UPPER DIVERGENCE ACROSS THE ITCZ WAS YIELDING ISOLATED TO 
SCATTERED MODERATE TO STRONG CONVECTION ALONG THE ITCZ AS 
DESCRIBED ABOVE. 

A SERIES OF SHORT WAVES HAVE BEEN MOVING EWD ACROSS THE CENTRAL 
AND NE PACIFIC...EMBEDDED IN THIS STRONG WLY FLOW ALOFT...AND 
HAVE BECOME INCREASINGLY NEGATIVELY TILTED IN TIME AS THEY 
APPROACHED THE W COAST OF THE U.S. DUE TO THE PERSISTENT POLAR 
VORTEX SE OF THE ALEUTIANS. THIS HAS ALLOWED FOR THIS STRONG 
UPPER FLOW INTO THE BAJA. A S/W TO THE HAS CROSSED 125W N OF 30N 
AND WAS SUPPORTING A FRONT MOVING INTO THE NW PORTIONS OF THE 
AREA. GALES TO 40 KT WERE OCCURRING BEHIND THIS FRONT ACROSS THE 
FORECAST AREA...WITH SEAS TO 25 FT IN LARGE NW SWELL. 

THIS STRONG UPPER FLOW WILL PERSIST FOR ANOTHER 48 HOURS AND 
ALLOW YET ANOTHER S/W TO MOVE ESE TO OFFSHORE OF CALIFORNIA AND 
CARVE OUT A CUT OFF UPPER LOW...AND YIELD A PROGRESSION OF COLD 
FRONTS MOVING ESE TO SE INTO THE AREA...EVENTUALLY MOVING SE 
ACROSS ALL OF BAJA CALIFORNIA BY FRI EVENING...AND ACROSS OLD 
MEXICO THIS WEEKEND...INTO THE GULF OF MEXICO...AND REACH FROM 
THE SW GULF ACROSS SRN MEXICO...TO NEAR 12N120W BY SUNDAY 
EVENING. 

GALES WILL SWEEP ACROSS N PORTIONS OF THE AREA N OF 26N DURING 
THE NEXT 12 TO 48 HOURS AND GENERATE HUGE SEAS IN NW SWELL THAT 
WILL PROPAGATE THROUGH THE ENTIRE AREA AND SLAM THE W COAST OF S 
AMERICA WITH HUGE SURF SUN AND MON. SEAS ACROSS THE FORECAST 
AREA WILL BUILD 15 TO 30+ FT IN LARGE NW SWELL BY THU 
EVENING...FROM THE SRN TIP OF BAJA SW AND W INTO THE TROPICS.    

GAP WINDS 

20-25 KT NE TO E WINDS WILL CONTINUE THROUGH GULF OF PAPAGAYO 
AND EXPECTED TO DIMINISH TO OR BELOW 20 KT BY FRI.

MODERATE TO STRONG NLY WIND ACROSS GULF OF PANAMA WILL DIMINISH 
BELOW 20 KT THU MORNING.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

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AL/STRIPLING