000
AXPZ20 KNHC 120955
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE MAR 11 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
THE MONSOON TROUGH EXTENDS SW FROM THE COAST OF COSTA RICA AT
09N84W TO 02N94W TO 04N110W WHERE SCATTEROMETER WINDS INDICATE A
TRANSISITION TO AN ITCZ WHICH THEN WIGGLES WESTWARD BETWEEN 03N AND
04N TO BEYOND 140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS
OBSERVED WITHIN 90 NM OF 05N89W AND 03N100W...AND ALSO WITHIN 
90 NM EITHER SIDE OF A LINE FROM 04N109W TO 08N113W TO 07N124W.

...DISCUSSION...

GULF OF TEHUANTEPEC...HIGH PRESSURE IN THE WAKE OF A COLD FRONT OVER
THE EASTERN BAY OF CAMPECHE IS CURRENTLY SURGING THROUGH THE CHIVELA
PASS INTO THE GULF OF TEHUANTEPEC AT MINIMAL GALE FORCE...WITH SEAS TO
11 FT. THESE MINIMAL GALE CONDITIONS ARE EXPECTED TO PERSIST THROUGH
LATE WED. A REINFORCING NORTHERLY SURGE OVER THE GULF OF MEXICO
WILL INCREASE TO GULF OF TEHUATEPEC DRAINAGE FLOW TO 45 KT WED NIGHT...
AND PERSIST THROUGH SUNRISE THU. MINIMAL STORM CONDITIONS ARE STILL A
POSSIBILITY BRIEFLY AROUND SUNRISE ON THU MORNING. THE SOUTHERN EXTENT
OF THE GALE FORCE WINDS SHOULD ARE EXPECTED TO REACH AS FAR S AS 
13N96.5W ON THU NIGHT...WITH RESULTANT SEAS MAXING ABOUT 19 FT. 
OVERALL...THE GRADIENT WILL BEGIN TO RELAX LATE THU...WITH GALE
CONDITIONS ENDING BY MIDDAY SAT.

GULF OF PAPAGAYO...NE WINDS WILL PULSE AT 15 TO 20 KT INCREASING TO 20 
TO 25 KT DURING THE LATE NIGHT HOURS BEGINNING LATE TUE NIGHT. THESE
CONDITIONS WILL SPREAD WSW TO NEAR 08N91W ON THU WITH SEAS THEN BUILDING
TO 9 FT. THE TIGHTENING GRADIENT WILL INCREASE THE WINDS TO 20 TO 30 KT
DURING THU NIGHT...WITH THIS EVENT PERISITING THROUGH AT LEAST SUN
MORNING.

GULF OF FONSECA...NE TO E WINDS WILL INCREASE TO 15 TO 20 KT ON THU
AND PERSIST THROUGH FRI MORNING...WITH THE SOUTHERN EXTENT OF 20 KT 
WINDS REACHING AS FAR S AS 03N81W.     

GULF OF PANAMA...NORTHERLY WINDS AT 10 TO 15 KT EXPECTED TO CONTINUE
THROUGH LATE WED...THEN PULSE AT 15 TO 20 KT THROUGH THE WEEKEND. 

GULF OF CALIFORNIA...THE GRADIENT BETWEEN A PACIFIC RIDGE AND A TROUGH
OVER MEANDERING ALONG THE SIERRA MADRE OCCIDENTAL OVER INTERIOR OLD
MEXICO IS SUPPORTING NW WINDS AT 15 TO 20 KT ACROSS THE GULF OF 
CALIFORNIA TO THE S OF 30N...WITH SEAS TO 5 FT IN LONG FETCH 
S-CENTRAL WATERS. THE GRADIENT WILL RELAX ON WED WITH WINDS
DIMINISHING TO 10 TO 15 KT.

A LONGWAVE TROUGH PATTERN OVER CENTRAL N AMERICA HAS ITS MEAN AXIS
CONTINUING SW ACROSS NORTHERN OLD MEXICO AND THE SOUTHERN GULF OF
CALIFORNIA...THROUGH 20N120W TO A BASE OVER THE TROPICAL PACIFIC AT
10N131W. AN UPPER RIDGE IS AMPLYFYING N ACROSS THE WESTERN PORTION
OF THE DISCUSSION AREA... WITH THE RIDGE CREST THEN PARRELLING THE
NW COAST OF THE CONUS. SOME UPPER MOISTURE IS SPILLING E ACROSS THE 
RIDGE AXIS NEAR 32N130W. OTHERWISE VERY DRY UPPER AIR IS INDICATED
W OF A LINE FROM 32N95W TO 20N115W TO 05N140W.     

AN UPPER RIDGE EXTENDS ROUGHLY E TO W ACROSS THE TROPICS ALONG 08N
FROM COLOMBIA TO A SHARP CREST AT 08N119W. WEAK UPPER DIFFLUENCE
HAS BEEN ENHANCING CONVECTION W OF 85W ALONG THE MONSOON TROUGH AND
ITCZ AS PREVIOUSLY DESCRIBED. THE RESULTANT UPPER DEBRIS MOISTURE 
IS ADVECTED NE ALONG THE PERIPHERY OF THE UPPER RIDGE IN THE FORM
OF A 480M NM WIDE TROPICAL PLUME THAT CROSSES CENTRAL OLD MEXICO
AND THE DISSECTS THE GULF OF MEXICO...EVENTUALLY FEEDING INTO THE
CONVECTION PRECEEDING THE COLD FRONT ADVANCING E ACROSS THE SE CONUS.

A SURFACE RIDGE EXTENDS FROM 32N132W TO 12N103W. THE GRADIENT SW
OF THE RIDGE IS SUPPORTING NE TRADES AT 20 TO 25 KT ACROSS THE
TROPICS FROM 03N TO 21N BETWEEN 122W AND 140W...WITH SEAS 7 TO 10 FT
IN NE SWELL. THE GRADIENT IS EXPECTED TO RALAX LATER TODAY THE 
AFFECTED AREA EXPECTED TO SHRINK WESTWARD OVER THE NEXT COUPLE OF DAYS.
  
$$
NELSON