000
AXPZ20 KNHC 272149
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAY 27 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 
2145 UTC.

...TROPICAL WAVES AND LOWS...

A TROPICAL WAVE ALONG 75W HAS BEEN MOVING W AN AN ESTIMATED 12 
KT AND THIS MOTION SHOULD MOVE THE WAVE INTO THE EPAC WATERS 
ALONG THE COAST OF COLOMBIA TONIGHT. 

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 11N86W TO 06N100W 
TO 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED WITHIN 90 NM EITHER SIDE OF LINE FROM 06N77W TO 08N84W TO 
06N104W AND ALSO WITHIN 30 NM OF LINE FROM 09N94W TO 13N100W.

...DISCUSSION...

A SLIGHTLY NEGATIVE TILT UPPER SHORTWAVE TROUGH DOMINATES THE NW 
PORTION OF THE AREA AREA. A TROPICAL UPPER ANTICYCLONE IS NEAR 
15N130W BUT SEEMS TO BE LOSING IDENTITY AS ANOTHER UPPER RIDGE 
BUILDS SW FROM A STATIONARY ANTICYCLONE OVER OLD MEXICO NEAR 
25N105W. AN UPPER TROUGH DOMINATES THE W CARIBBEAN WITH ITS AXIS 
EXTENDING THROUGH CYCLONES AT 21N77W AND 15N90W WITH THE TROUGH 
CONTINUING SW TO BASE NEAR 08N92W. THE REMAINDER OF THE TROPICAL 
PAC IS DOMINATED BY WEAK RIDGING FROM THE ANTICYCLONE NEAR 
24N103W.  

UPPER DIFFLUENCE IS ENHANCING CONVECTION OVER THE AREA FROM 05N 
TO 15N BETWEEN 75W AND 105W. THE RESULTANT DEBRIS MOISTURE 
REMAINS S OF 16N W OF 82W AS THE DRY UPPER AIR ACCOMPANYING THE 
CARIBBEAN TROUGH SEEMS TO EVAPORATE THE MOISTURE. SOME OF THIS 
MOISTURE CONTINUES TO SPREAD S OF THE EQ BETWEEN 70W AND 105W. 
SOME UPPER MOISTURE IS ALSO NOTED OVER THE NW PORTION...TO THE N 
OF 27N W OF 115W AND THE IT TURNS NE AS IT MOVES OVER SOUTHER 
CALIFORNIA. ELSEWHERE THE UPPER LEVELS APPEAR VERY DRY AND 
SUPPRESSES CONVECTION ALONG THE ITCZ BETWEEN 120W AND 146W.  

AT THE SURFACE A BROAD RIDGE DOMINATES THE AREA N OF THE ITCZ W 
OF 117W. NORTHERLY SWELLS TO 9 FEET CONTINUE OVER THE AREA FROM 
10N TO 20N W OF 130W BUT ARE SUBSIDING AND SHOULD BE LESS THAN 8 
FEET ON WED. NW WINDS TO 20 KT ARE ALONG THE W COAST OF THE BAJA 
PENINSULA .

A BROAD AREA OF SURFACE LOW PRESSURE DOMINATES THE SW CARIBBEAN 
AND THE E PAC ALONG THE COAST OF CENTRAL AMERICA. SEVERAL 
CYCLONIC SWIRLS ARE NOTED WITHIN THIS AREA WITH THE MOST 
PRONOUNCED SWIRL NEAR 09N89W...IN THE AREA WHERE OUR MARINE 
PRODUCTS HAVE SUGGESTED A SURFACE LOW WOULD DEVELOP. MODEL 
GUIDANCE CONTINUES TO SUGGEST THAT THIS LOW PRESSURE WILL 
MEANDER IN THIS AREA FOR THE NEXT DAY OR SO...AND PERHAPS DRIFT 
NE LATER THIS WEEK. THE UPPER PATTERN DESCRIBED IN DETAIL ABOVE 
IS ALSO NOT EXPECTED TO CHANGE DURING FOR THE FIRST 24 HOURS 
THEN AN UPPER LOW WILL SPIN UP OVER THE BAY OF CAMPECHE...WHILE 
AN UPPER ANTICYCLONE DEVELOPS OVER THE SW CARIBBEAN. THIS WOULD 
ALLOW A SURFACE LOW TO MOVE NW ACROSS CENTRAL AMERICA OVER GULF 
OF HONDURAS. THE APPROACHING TROPICAL WAVE MAY ADD THE NEEDED 
LOW LEVEL VORTICITY TO GET THIS SPINNING. NOTE THAT THE GRADIENT 
S OF THIS LOW PRESSURE IS ALREADY SUPPORTING A SW TO W 20 TO 25 
KT WIND AND SEAS TO ABOUT 10 FT. THESE CONDITIONS ARE EXPECTED 
TO PERSIST S OF THE LOW THROUGH 48 HOURS.

$$
NELSON