000
AXPZ20 KNHC 220947
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU MAY 22 2008

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

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

...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED N OF 3N ALONG 84W AND HAS BEEN 
MOVING W AT ESTIMATED 15 KT. BROAD CYCLONIC TURNING IS NOTED 
NEAR THE WAVE 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 07N93W TO 11N113W TO 
06N130W TO 05N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED FROM FROM 03N TO 09N E OF 100W AND ALSO 
DISSIPATING WITHIN 90 NM OF 11N112W AND STEADY STATE WITHIN 180 
NM EITHER SIDE OF LINE 06N119W TO 11N123W. 

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS WELL W OF THE AREA NEAR 26N148W BUT 
ITS ENVELOPE OF CYCLONIC FLOW STILL COVERS THE UPPER LEVELS OF 
THE DISCUSSION AREA TO THE N OF 18N AND W OF 137W.

AN UPPER CYCLONE OVER S TEXAS NEAR 29N99W IS LIFTING TO NE AS A 
NEGATIVE TILT LONG WAVE TROUGH DIGS IN OVER WESTERN N AMERICA.
AN EMBEDDED DEEP LAYERED CYCLONE IS DEVELOPING NEAR 39N113W. 
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 ALREADY ALONG 
32N113W TO A BASE NEAR 13N108W.

FURTHER TO THE SW A TROPICAL UPPER ANTICYCLONE HAS FORMED NEAR 
08N138W WITH A SHORTWAVE RIDGE EXTENDING NE TO A SHARP CREST AT 
15N126W. ALL OF THESE UPPER FEATURES ARE ACCOMPANIED BY VERY DRY 
AIR ALOFT...INDICATED ON WATER VAPOR CHANNEL TO N OF 15N 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 15N77W WITH A 
RIDGE EXTENDING SW INTO THE PAC TO NEAR 11N95W. 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 E MEXICO AT 15N91W TO THE CENTRAL GULF 
OF MEXICO AT 25N90W...THEN THE PLUME TURNS E ACROSS CENTRAL 
FLORIDA AND CONTINUE ENE TO BEYOND BERMUDA. 

AT THE SURFACE...SCATTERED MODERATE TO STRONG CONVECTION IS 
NOTED N OF THE ITCZ...N OF 11N BETWEEN 88W AND 93W. 

HIGH PRES N OF THE AREA RIDGES SE ALONG 32N133W 
TO NEAR 13N115W. TO THE NE OF THE RIDGE...A SERIES OF COLD 
FRONTS WILL SWEEP SE INTO NORTHERN BAJA AREA THE NEXT FEW DAYS 
WITH LOW LEVEL WINDS SHIFTING FROM SW TO NW AT 20 TO 30 KT.
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.

WINDS OVER THE NORTHERN GULF OF CALIFORNIA WILL BECOME PRIMARILY 
SW AND PEAKING AT 30 KT AS THE DEEP LAYERED CYCLONE DEEPENS TO 
THE N. EXPECTING SW SWELLS TO DEVELOP BUILDING COMBINED SEAS TO 
A MAX OF 11 FT NEAR 31N113W FRI THEN SUBSIDE A FEW FT SAT.       

$$
NELSON