000
AXPZ20 KNHC 170301
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED MAR 17 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 
0100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED FROM 04N77W TO 
03N90W TO 04N105W TO 04N115W TO 04N140W. SCATTERED MODERATE 
CONVECTION WAS WITHIN 270 NM N OF THE ITCZ AXIS BETWEEN 82W AND 
90W AS WELL AS WITHIN 210 NM N OF THE ITCZ AXIS E OF 78W AND S 
OF THE ITCZ AXIS TO EQUATOR E OF 81W. A TROUGH IS EMBEDDED IN 
THE ITCZ FROM 09N103W TO 01N109W. ISOLATED MODERATE CONVECTION 
WAS WITHIN 210 NM E OF THE TROUGH.

...DISCUSSION...
A BROAD UPPER LEVEL TROUGH IS OVER THE FAR NW PORTION OF THE 
DISCUSSION AREA N OF 25N W OF 125W. A 100-120 KT JETSTREAM IS 
ROUNDING THE SOUTH SIDE OF THE TROUGH AND IS CENTERED ALONG 27N 
W OF 125W. DOWNSTREAM UPPER LEVEL RIDGE COVERS THE AREA N OF 20N 
E OF 120W. STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE 
AND UPPER LEVELS OF THE ATMOSPHERE IS WITHIN THE RIDGE. ANOTHER 
UPPER LEVEL TROUGH EXTENDS FROM A WELL DEFINED CYCLONIC 
CIRCULATION OVER EASTERN TEXAS ACROSS THE WESTERN GULF OF MEXICO 
TO JUST W OF THE ISTHMUS OF TEHUANTEPEC. SW FLOW SE AND S OF THE 
TROUGH IS ADVECTING ABUNDANT TROPICAL MOISTURE ALOFT ACROSS 
SOUTHERN MEXICO. IN THE DEEP TROPICS...AN ANTICYCLONIC 
CIRCULATION IS CENTERED NEAR 07N91W WITH A RIDGE EXTENDING FROM 
THE ANTICYCLONE W TO 07N115W AND E INTO SOUTHERN COSTA RICA/NW 
PANAMA. MODERATE TO STRONG SUBSIDENCE IS FOUND OVER CENTRAL 
AMERICA NORTH OF THE RIDGE AXIS. SCATTERED MODERATE TO STRONG 
CONVECTION WAS NEAR THE ITCZ E OF 81W UNDER WEAKLY DIFFLUENT 
FLOW ALOFT NEAR THE COAST OF COLOMBIA/ECUADOR.

STATIONARY FRONT EXTENDS FROM 30N131W TO 26N140W. NE WINDS OF 
20-25 KT WERE W OF THE FRONT WITH SEAS 14 TO 17 FT IN NW SWELL. 
THE FRONT IS FORECAST TO DISSIPATE OVERNIGHT. THE ASCAT PASS 
FROM 1810 UTC SHOWS FRESH TRADES ARE CONFINED PRIMARILY FROM 07N 
TO 18N W OF 125W. A TROUGH IS ANALYZED EMBEDDED IN THE ITCZ FROM 
09N103W TO 01N109W. CONVECTION HAS WANED OVER THE PAST FEW HOURS 
NEAR THIS FRONT AS THE DIFFLUENT REAR RIGHT QUADRANT OF THE 
UPPER JET THAT EXTENDS FROM THE GULF OF MEXICO TO NEAR 11N106W 
HAS PULLED EASTWARD AND WEAKENED.

GAP WINDS IN THE GULF OF TEHUANTEPEC ARE BELIEVED TO HAVE 
INCREASED ABOVE 20 KT. THE HIGH RESOLUTION ASCAT PASS FROM 1628 
UTC SHOWED N WINDS TO 20 KT NEAR THE COAST WHILE THE VISIBLE 
SATELLITE IMAGERY FROM 1715 TO 1945 UTC SHOWED A ROPE CLOUD 
TYPICALLY FOUND ON THE LEADING EDGE OF THE WIND SURGE PASSING S 
AWAY FROM THE GULF OF TEHUANTEPEC. WINDS WILL BLAST QUICKLY TO 
GALE FORCE OVERNIGHT 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 48 HOURS BEFORE 
DIMINISHING...WITH WINDS REACHING NEAR STORM FORCE ON WED.

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

$$
SCHAUER