000
AXPZ20 KNHC 150332
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JAN 15 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS IS ANALYZED ALONG 02N78W TO 06N90W TO 05N104W TO 06N115W TO 
06N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WAS 
NOTED WITHIN 45 NM EITHER SIDE OF THE AXIS BETWEEN 93W AND 99W 
AND WITHIN 90 NM N OF THE AXIS BETWEEN 106W AND 114W. SCATTERED 
MODERATE CONVECTION WAS NOTED WITHIN 60 NM N OF THE AXIS BETWEEN 
115W AND 120W.

...DISCUSSION...
A BROAD MID TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED 
NEAR 13N137W. A RIDGE AXIS EXTENDS FROM THE CIRCULATION TO 
31N129W. MODERATE TO STRONG SUBSIDENCE WITH A VERY DRY AND 
STABLE AIR MASS IS N OF THE ITCZ TO 24N W OF 100W...HOWEVER SOME 
MID TO HIGH LEVEL CLOUDS ARE MOVING THROUGH THE FAR NW CORNER OF 
THE DISCUSSION AREA AHEAD OF AN APPROACHING UPPER LEVEL TROUGH W 
OF THE AREA. DOWNSTREAM AN UPPER LEVEL TROUGH AXIS EXTENDS FROM 
A CYCLONIC CIRCULATION OVER SE NEW MEXICO ACROSS MEXICO TO NEAR 
10N113W. AN ANTICYCLONIC CIRCULATION IS OVER NORTHERN COLOMBIA 
WITH A RIDGE EXTENDING SW ACROSS PANAMA TO 04N88W. A 110-160 KT 
NORTHERLY JETSTREAM EXTENDS FROM NW MEXICO JUST E OF THE GULF OF 
CALIFORNIA NEAR 30N110W TO 21N104W.

AT THE SURFACE...1025 MB HIGH PRES IS CENTERED NEAR 34N125W WITH 
A RIDGE COVERING THE AREA N OF 15N W OF 107W. A TIGHT PRES 
GRADIENT INDUCED BY THE RIDGE IS PRODUCING STRONG NE-E TRADES 
ALONG THE SOUTHERN PERIPHERY. A COLD FRONT IS APPROACHING 140W 
FROM THE NW WITH SOUTHERLY WINDS INCREASING TO 20-30 KT N OF 26N 
W OF 135W...WITH 30 KT WINDS REPORTED AT 0000 UTC BY A SHIP WITH 
CALL-SIGN WSLH NEAR 30N139W.

A TIGHT PRES GRADIENT ALSO REMAINS IN PLACE OVER THE GULF OF 
CALIFORNIA DUE TO THE HIGH W OF THE BAJA PENINSULA AND 
TROUGHINESS OVER MAINLAND MEXICO. AS A RESULT STRONG NORTHERLY 
WINDS ARE OCCURRING IN THE GULF OF CALIFORNIA N OF 24N. A LOCAL 
FORECAST TOOL BASED ON PREVIOUS RESEARCH NOW DIAGNOSES A HIGH 
PROBABILITY OF GALE FORCE WINDS...AND HAVE THEREFORE ISSUED A 
GALE WARNING N OF 26N IN THE GULF OF CALIFORNIA. IN ADDITION A 
RARE JASON ALTIMETER PASS CAPTURED 8 TO 10 FT SEAS IN THE GULF. 
WINDS WILL DIMINISH TO LESS THAN GALE FORCE BY EARLY FRI...THEN 
TO LESS THAN 20 KT BY EARLY SAT. 

THREE WEAK SURFACE TROUGHS ARE EMBEDDED IN THE ITCZ. THE EASTERN 
MOST TROUGH EXTENDS FROM 09N104W TO 01N105W. ISOLATED SHOWERS 
ARE CONFINED TO THE MIDDLE PORTION OF THE TROUGH FROM 04N TO 
06N. A SECOND TROUGH EXTENDS FROM 09N113W TO 01N114W. ISOLATED 
SHOWERS ARE ALONG THE TROUGH AXIS FROM 05N TO 09N. ANOTHER 
TROUGH IS TO THE W EXTENDING FROM 09N135W TO 04N136W. ISOLATED 
SHOWERS ARE ALONG THE TROUGH AXIS.

...GAP WINDS...
GULF OF PANAMA...STRONG NORTHERLY WINDS CONTINUE N OF 05N 
BETWEEN 79W AND 81W. WINDS ARE EXPECTED TO DIMINISH TO LESS THAN 
20 KT BY EARLY FRI.

GULF OF PAPAGAYO...NE-E WINDS OF 20 TO 30 KT CONTINUE IN THE 
GULF OF PAPAGAYO AND DOWNSTREAM TO 90W AS CAPTURED AT 0000 UTC 
BY A SHIP WITH CALL-SIGN WRFJ. THESE WINDS WILL GRADUALLY 
DIMINISH TO NEAR 20 KT ON FRI...THEN WILL PULSE UP AND DOWN 
THEREAFTER TO ABOVE/BELOW 20 KT DUE PRIMARILY TO DIURNALLY 
DRIVEN DRAINAGE FLOW.

GULF OF TEHUANTEPEC...HIGH PRES WILL BUILD DOWN ALONG THE SW 
GULF OF MEXICO COAST AND WESTERN BAY OF CAMPECHE ON SAT...AND 
NORTHERLY WINDS WILL INCREASE IN THE GULF OF TEHUANTEPEC TO 
20-25 KT BY SUN EVENING.

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

$$
LEWITSKY