000
AXPZ20 KNHC 150247
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI MAR 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
MONSOON TROUGH AXIS FROM 10N85W TO 01N100W TO 01N108W THEN ITCZ
FROM 04N122W TO 03N104W.  SCATTERED MODERATE CONVECTION WITHIN
150 NM SE OF MONSOON TROUGH AXIS E OF 89W.

...DISCUSSION...
UPPER LEVEL LONGWAVE TROUGH SHIFTED E ACROSS CONUS WITH VIGOROUS
CUT OFF CYCLONE OVER SOUTHERN TIP OF BAJA CALIFORNIA PENINSULA
AND TROUGH EXTENDING SW TO 02N115W.  UPPER LEVEL RIDGE CREST W 
OF CYCLONE HOLDS ITS GROUND AS SECOND LONG WAVE TROUGH APPROACH
WESTERN FRINGES OF E PAC WITH ITS ATTENDANT COLD FRONT.  RIDGE
SUPPORTS SURFACE HIGH PRES CENTER 1026 MB WHICH THEN BLOCKS ANY
FURTHER EASTERN INTRUSION OF COLD FRONT INTO BASIN.  ABUNDANT 
MOISTURE ALOFT IS ADVECTED ON E SIDE OF RIDGE CREST BUT MOVES
INTO REGION OF DRY AND STABLE AIR MASS WITH LITTLE IMPACT 
EXPECTED FROM IT.

MODEL GUIDANCE SOLUTIONS WEAKEN UPPER LEVEL CYCLONE OVER BAJA 
CALIFORNIA INTO AN OPEN TROUGH LATE SAT AND UPPER LEVEL WINDS E
OF 100W BECOME MOSTLY ZONAL AS SURFACE HIGH PRES CENTER OVER 
GULF OF MEXICO DRIFTS E AND ALLOW WINDS FUNNELING ACROSS 
CHIVELAS PASS INTO GULF OF TEHUANTEPEC TO DIMINISH BY END OF 
FORECAST PERIOD.

...ELSEWHERE AT THE LOWER LEVELS...
GALE FORCE WINDS REMAIN ACROSS GULF OF TEHUANTEPEC TONIGHT 
THROUGH FRI NIGHT BEFORE QUICKLY DIMINISHING BELOW 20 KT LATE
IN THE FORECAST PERIOD.

ON THE OTHER HAND...AS GULF OF MEXICO HIGH PRES CENTER MOVES E
CARIBBEAN GRADIENT TIGHTENS PRODUCING STRONG NE WINDS ACROSS
MOUNTAIN GAPS IN NICARAGUA BRINGING STRONG TO NEAR GALE FORCE 
WINDS TO GULF OF PAPAGAYO PEAKING FRI NIGHT THEN DIMINISHING 
BY END OF FORECAST PERIOD.  DOWNSTREAM FROM GULFS OF PAPAGAYO
AND TEHUANTEPEC...SWELLS CAUSED BY THEIR RESPECTIVE WIND EVENTS
MERGE CREATING A REGION OF 8-10 FT SEAS S OF 13N FROM 90W TO 
BEYOND 110W. 

APPROACHING COLD FRONT BRIEFLY INCREASE SE-S WINDS N OF 25N W OF 
135W TO A MODERATE BREEZE FRI BUT QUICKLY RETURN TO A GENTLE 
BREEZE AS COLD FRONT LOSES UPPER LEVEL SUPPORT AND SHIFT NE OF 
BASIN.   
  
$$
WALLY BARNES