000
AXPZ20 KNHC 232129
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI MAY 23 2008

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...
TROPICAL WAVE N OF 03N ALONG 84W NEARLY STATIONARY. THE WAVE IS 
BECOMING INCREASINGLY DIFFICULT TO TRACK IN THE FACE OF A LARGE 
SWATH OF SURFACE WESTERLY WINDS. BROAD AREA OF ACTIVE CONVECTION 
HAS DIMINISHED SLIGHTLY FROM THIS MORNING...ALTHOUGH SCATTERED 
MODERATE CONVECTION IS STILL NOTED WITHIN 180 NM W OF AXIS.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...09N84W TO 
06N91W TO 12N114W TO 04N140W. SCATTERED MODERATE TO STRONG 
WITHIN 90 NM OF THE AXIS BETWEEN 115W AND 130W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 120 NM OF THE AXIS BETWEEN 105W 
AND 115W...AND FROM 03N TO 09N BETWEEN 80W AND 102W.

...DISCUSSION...
A LARGE UNSEASONABLE COLD CORE LOW IS CENTERED OVER NEVADA THIS 
AFTERNOON. FURTHER WEST...AN UPPER ANTICYCLONE IS SQUEEZED 
BETWEEN THE BROAD DEEP-LAYER CYCLONIC FEATURE OVER THE 
INTERMOUNTAIN WEST...AND A VIGOROUS SHORT WAVE NEAR 32N145W. 
NORTHERLY FLOW BETWEEN THE UPPER ANTICYCLONE AND THE UPPER LOW 
OVER THE WESTERN U.S. IS KEEPING THE MID AND UPPER LEVELS OF THE 
ATMOSPHERE FAIRLY DRY NORTH OF 15N. AT THE SURFACE...A TIGHT 
GRADIENT HAS SET UP BETWEEN A 1029 MB SURFACE HIGH N OF THE 
AREA...AND DEEP LOW PRES OVER SOUTHERN NEVADA. SHIP OBSERVATIONS 
AND SCATTEROMETER DATA SHOW ASSOCIATED FRESH TO STRONG NLY FLOW 
PUSHING AS FAR SOUTH AS 25N. SHIPS ARE ALSO CONFIRMING WAVEWATCH 
MODEL INITIALIZATION OF LONG PERIOD NORTH SWELL UP TO 17 FT OFF 
BAJA. QUIKSCAT ALSO SHOWS SOME ENHANCED GAP WINDS IN THE GULF OF 
CALIFORNIA BETWEEN MOUNTAIN PASSES OVER BAJA...PARTICULARLY IN 
THE NORTHERN GULF. SHIP...QUIKSCAT AND LAND OBSERVATIONS ALSO 
SHOWING ENHANCED WEST FLOW OFF THE MEXICAN COAST BETWEEN 
MANZANILLO AND ACAPULCO...BETWEEN A WEAK 1013 MB SURFACE HIGH 
SOUTH OF LOS CABOS AND 1001 MB LOW PRES OVER CENTRAL MEXICO. 
MEANWHILE...AN UPPER RIDGE AXIS EXTENDING FROM THE NW CARIBBEAN 
TO NEAR 10N110W IS PROVIDING UPPER EXHAUST TO SUPPORT CONVECTION 
ALONG THE ITCZ AS MENTIONED ABOVE. 

LOOKING AHEAD THROUGH THE WEEKEND...THE SURFACE HIGH TO THE 
NORTH WEAKENS THUS ALLOWING NLY WINDS TO DIMINISH AS NLY SWELL 
DECAYS. WINDS OVER THE GULF OF BAJA DIMINISH AS WELL. GLOBAL 
MODELS SHOW THE FRESH WESTERLY WINDS OFF THE MEXICAN COAST 
CONTINUING TO LATE SATURDAY MAINLY DUE TO THE LOW PRES OVER 
CENTRAL MEXICO. CONVECTION STAYS FAIRLY ACTIVE ALONG THE ITCZ 
MAINLY E OF 100W INTO NEXT WEEK...GIVEN ABUNDANT TROPICAL 
MOISTURE AND FAIRLY WINDS ALOFT.   

$$
CHRISTENSEN