000
AXPZ20 KNHC 171527
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAR 17 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 IS ALONG 05N77W TO 05.5N107W TO 04N116W TO 03N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM 
EITHER SIDE OF AXIS E OF 88W. SCATTERED MODERATE CONVECTION 
WITHIN 180 NM EITHER SIDE OF AXIS BETWEEN 101W AND 110W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM 
EITHER SIDE OF AXIS W OF 121W. 

...DISCUSSION...
A BROAD UPPER LEVEL TROUGH IS OVER THE FAR NW PORTION OF THE 
DISCUSSION AREA N OF 25N W OF 120W...WITH RIDGING PREVAILING N 
OF 12N ACROSS THE REMAINDER OF THE AREA. STRONG SUBSIDENCE WITH 
DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE 
IS WITHIN THE RIDGE. IN THE DEEP TROPICS...ACTIVE CONVECTION 
ACROSS THE ITCZ IS MAINTAINING RIDGING ACROSS MUCH OF THE AREA S 
OF 12N. A HIGH AMPLITUDE UPPER LEVEL TROUGH PREVAILS N OF THE 
HAWAIIAN ISLANDS. THIS TROUGH WILL SHIFT E AND BECOME NEGATIVELY 
TILTED...SHIFTING ITS ASSOCIATED SURFACE LOW AND COLD FRONT 
EAST. THIS WILL WEAKEN HIGH PRESSURE N OF THE AREA...MENTIONED 
IN THE NEXT PARAGRAPH.  

AT THE SURFACE...HIGH PRESSURE 1035 IS LOCATED WELL N OF THE 
AREA NEAR 41N131W. THIS IS HELPING MAINTAIN A SMALL AREA OF 
FRESH TRADES ACROSS THE W PART OF THE AREA. NW SWELL PREVAILS N 
OF 12N...THEN MIXED WITH SW SWELL S OF 12N. AS THE HIGH PRESSURE 
N OF THE AREA WEAKENS...THE COVERAGE OF 20 KT TRADES WILL 
DECREASE. THE WEAKENING RIDGE WILL ALSO ENABLE A SURFACE COLD 
FRONT....MENTIONED IN PREVIOUS PARAGRAPH...TO ENTER THE FAR NW 
PART OF THE AREA WITHIN 48 HOURS. 

GAP WINDS
GALE FORCE WINDS ARE AFFECTING THE GULF OF TEHUANTEPEC AS STRONG 
HIGH PRES BUILDS OVER THE WESTERN GULF OF MEXICO AND TIGHTENS 
THE PRESSURE GRADIENT OVER SOUTHERN MEXICO. GALES ARE EXPECTED 
TO PERSIST THROUGH THU.

WINDS WILL INCREASE TO 20 KT OVER THE GULF OF PAPAGAYO THU. 
 
FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

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AL