000
AXPZ20 KNHC 221612
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU MAY 22 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED N OF 3N ALONG 80W AND HAS BEEN 
MOVING W AT AN ESTIMATED 10 KT. THE WAVE IS ENCOUNTERING A BROAD 
AREA OF WESTERLY LOW LEVEL FLOW AND THEREFORE IS VERY DIFFICULT 
TO TRACK. IN ANY EVENT BROAD CYCLONIC TURNING IS NOTED NEAR THE 
WAVE AXIS AND THE WAVE IS UNDER AN UPPER RIDGE WITH THE 
ASSOCIATED UPPER DIFFLUENCE ENHANCING CONVECTION OVER THE ENTIRE 
AREA FROM 03N IN THE PAC TO ALONG 15N IN THE W CARIBBEAN AND 
SPREADING W OVER CENTRAL AMERICA TO ALONG 92W.

...ITCZ...

THE ITCZ AXIS IS ALONG LINE 09N83W TO 08N95W TO 10N115W TO 
05N140W. SCATTERED MODERATE ISOLATED STRONG FROM 03N TO 08N E OF 
88W...AND WITHIN 90-120 NM OF THE AXIS BETWEEN 110W AND 126W. 
SCATTERED MODERATE WITHIN 120 NM OF THE AXIS BETWEEN 88W AND 
100W. 

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS WELL W OF THE AREA NEAR 29N148W BUT 
ITS ENVELOPE OF CYCLONIC FLOW STILL COVERS THE UPPER LEVELS OF 
THE DISCUSSION AREA TO THE N OF 18N AND W OF 137W. THE CYCLONE 
IS TURNING MORE TO THE NORTH IN RESPONSE TO A NARROW BUILDING 
RIDGE TO THE EAST. 

AN UPPER CYCLONE OVER E TEXAS IS LIFTING TO NE AS A NEGATIVE 
TILTED LONG WAVE TROUGH DIGS IN OVER WESTERN N AMERICA. AN 
EMBEDDED DEEP LAYERED CYCLONE IS DEVELOPING NEAR 35N112W. THIS 
CYCLONE WILL BECOME THE DOMINATING FEATURE THE REMAINDER OF THE 
WEEK AS A SERIES SHORTWAVE TROUGHS ROTATE SE AROUND ITS CENTER 
OVER THE NE PORTION OF THE DISCUSSION AREA INTO A BROAD UPPER 
TROUGH. THIS LARGE TROUGH HAS ITS AXIS ALONG 32N113W TO A BASE 
NEAR 14N110W. STRONG UPPER LEVEL SUBSIDENCE ACCOMPANIES MOST OF 
THE TROUGH. 

FURTHER TO THE SW A TROPICAL UPPER ANTICYCLONE HAS FORMED NEAR 
08N140W WITH A SHORTWAVE RIDGE EXTENDING NE TO A SHARP CREST AT 
17N125W. ALL OF THESE UPPER FEATURES ARE ACCOMPANIED BY VERY DRY 
AIR ALOFT...INDICATED ON WATER VAPOR CHANNEL TO N OF 12N W OF 
125W. SE OF THIS SAME SHORTWAVE RIDGE CONVECTION IS ENHANCED 
ALONG THE ITCZ BETWEEN 110W AND 130W...WITH THE RESULTANT DEBRIS 
MOISTURE ADVECTED S OF THE EQUATOR AT 133W.

AN UPPER ANTICYCLONE IS OVER THE CARIBBEAN AT 16N78W WITH A 
RIDGE EXTENDING SW INTO THE PAC TO NEAR 09N105W. AS MENTIONED 
ABOVE THE UPPER DIFFLUENCE HAS ENHANCED CONVECTION E OF THIS 
RIDGE WITH THE RESULTANT DEBRIS MOISTURE CONCENTRATING INTO A 
PLUME AROUND THE W PERIPHERY OF THE RIDGE...ROUGHLY WITH 240 NM 
EITHER SIDE OF LINE FROM CENTRAL AMERICA NEAR 14N90W TO THE 
E-CENTRAL GULF OF MEXICO NEAR 25N86W...THEN THE PLUME TURNS E 
ACROSS CENTRAL FLORIDA AND CONTINUE ENE TO BEYOND BERMUDA. 

HIGH PRES N OF THE AREA RIDGES SE ALONG 32N135W TO NEAR 13N115W. 
TO THE NE OF THE RIDGE...A SERIES OF SURFACE TROUGHS WILL SWEEP 
SE INTO NORTHERN BAJA AREA THE NEXT FEW DAYS WITH SURFACE WINDS 
SHIFTING FROM SW TO NW AT 20 TO 30 KT WITH HIGHER GUSTS. THIS 
WILL DRIVE LARGE NW SWELLS TO ABOUT 20 FT WITH THEIR PERIOD 
INCREASING TO ABOUT 12 SECONDS INTO THE AREA FRI AND SAT WITH 
SEAS TO 8 FT REACHING TO 15N W OF 110W MID DAY SAT.

HIGH RESOLUTION QUIKSCAT DATA INDICATED SW WINDS OVER THE 
NORTHERN GULF OF CALIFORNIA ARE FROM THE SW AT 25-30 KT IN 
RESPONSE TO THE DEEPENING LOW PRESSURE TO THE N. DESPITE THE 
SHORT FETCH LENGTH SW WINDS OF 30 KT WILL ALLOW FOR BUILDING 
COMBINED SEAS TO A MAX OF 10 FT AT THE FAR NORTHERN END OF THE 
GULF OF CALIFORNIA.

$$
COBB