000
AXPZ20 KNHC 182116
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU MAY 18 2006

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N77W 7N87W 10N104W 8N113W 6N123W 
6N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 
100 NM EITHER SIDE OF LINE FROM 5N88W TO 9.5N87W. SCATTERED 
MODERATE AND ISOLATED STRONG IS WITHIN 100 NM OF THE AXIS FROM 
100W-106W AND WITHIN 75 NM OF LINE 8N113W 10N116W TO 10N119W. 
SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF LINE FROM 8N96W
TO 9N99W...WITHIN A 45 NM RADIUS OF 6N113W...AND 30 NM OF LINE 
5N117W TO 4N122W.

ELSEWHERE...SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF COAST 
OF NRN COSTA RICA AND SRN NICARAGUA FROM 9.5N TO 11.5N. SIMILAR 
CONVECTION IS WITHIN 20 NM OF LINE FROM 14N103W TO 15.5N99W.

...DISCUSSION...

W OF 110W...
DEEP-LAYERED LOW JUST N OF THE AREA NEAR 32.5N138W IS BEGINNING TO 
LIFT SLIGHTLY NE BUT THE MAIN TROUGH STILL EXTENDS S TO ABOUT 20N 
NEAR 140W.  UPPER LEVEL CONFLUENCE NEAR THE BASE OF THE TROUGH IS 
CREATING AN AREA OF MODERATE TO STRONG SUBSIDENCE JUST E OF THE 
HAWAIIAN ISLANDS THAT PROTRUDES INTO THE AREA WITHIN 120 NM OF 
LINE 19N150W 19N145W TO 23N136W. MODERATE SUBSIDENCE COVERS THE 
REMAINDER OF THE AREA FROM ABOUT 20N-30N W OF 134W. A WEAKENING 
COLD FRONT IS ASSOCIATED WITH THE TROUGH AND EXTENDS FROM 30N133W 
TO 23N140W...WITH NEARLY ALL OF THE SHOWER/TSTM ACTIVITY LOCATED N 
OF THE AREA. AN UPPER RIDGE IS ALIGNED ALONG 125W AND IS LOCATED 
JUST UPSTREAM OF A WEAKENING UPPER LOW OVER CNTRL BAJA CALIFORNIA. 
AN AREA OF STRONG SUBSIDENCE EXTENDS UP TO 400 NM S AND W OF THE 
LOW AND COVERS THE AREA N OF 18N E OF 120W. FARTHER S...AN UPPER 
RIDGE AXIS EXTENDS WESTWARD ALONG 10N BETWEEN 110W AND 140W WITH 
THE ITCZ MOISTURE AXIS LYING ALONG AND SWD TO ABOUT 5N.

E OF 110W...
WITH BROAD MID/UPPER TROUGHING OVER WRN MEXICO...TROPICAL MOISTURE 
IS BEING ADVECTED NEWD FROM NEAR THE ITCZ BETWEEN 90W-105W ACROSS
TOWARDS COASTAL SECTIONS OF MEXICO AND MOST OF CNTRL AMERICA. 
HOWEVER...SOME MID LEVEL DRYING IS SEEN IN WATER VAPOR IMAGERY 
ACROSS MUCH OF INTERIOR SE MEXICO AND OVER THE YUCATAN PENINSULA.
SMALL MID/UPPER LEVEL HIGH IS CENTER OVER NICARAGUA NEAR 12N85W 
WITH BROAD RIDGE EXTENDING W ALONG 9N100W TO BEYOND 10N100W.
CLUSTERS OF TSTMS CONTINUE TO PULSING OVER THE FAR EASTERN PACIFIC 
PRIMARILY DUE TO CONVERGENCE OF LOW-LEVEL SLY FLOW AND THE ENHANCED
BROAD RIDGING ALOFT.  

GAP WINDS OVER THE TEHUANTEPEC REGION HAVE CREATED A CLEAR SLOT 
IN THE CLOUDINESS N OF 12N BETWEEN 93W-98W...AND ARE ALSO CREATING 
SEVERAL CYCLONIC/ANTICYCLONIC SURFACE CIRCULATIONS AS THEY INTERACT 
WITH THE ITCZ.

$$
BROWN