000
AXPZ20 KNHC 051531
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAY 05 2007

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

AXIS IS CENTERED ALONG 6N78W 10N95W 8N106W 10N118W 5N140W.  
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF AXIS BETWEEN 
81W-83W. CLUSTERS OF SCATTERED MODERATE WITHIN 180 NM S OF AXIS 
BETWEEN 91W-97W AND WITHIN 180 NM N OF AXIS BETWEEN 101W-109W. 
SIMILAR ACTIVITY IS FROM 6N-11N BETWEEN 112W-120W. 

...DISCUSSION...

SUBTROPICS...
A LARGE SCALE MID TO UPPER LEVEL RIDGE/TROUGH PATTERN LIES ABOVE 
THIS REGION. THE RIDGING EXTENDS NWD FROM THE DEEP TROPICS TO AN 
UPPER ANTICYCLONE LOCATED NEAR 30N133W AND THEN REACHES A CREST 
WELL N TO SW CANADA. THE UPPER PATTERN FOLDS INTO A BROAD TROUGH 
E OF 125W ANCHORED BY AN UPPER LOW OVER THE ROCKIES. A WLY UPPER 
JET BRANCH WITH CORE WINDS IN THE 80-100 KT RANGE ORIGINATES 
NEAR THE SW BASE OF THE TROUGH AND EXTENDS EWD TOWARD SRN BAJA 
ALONG 23N130W 22N110W. THE OVERALL CONFLUENT PATTERN ALOFT N OF 
THE JET IS LEADING TO DRY AND STABLE CONDITIONS SUPPRESSING ANY 
DEEP CLOUDINESS. AT THE SFC...TIGHTENED PRES GRADIENT BETWEEN 
HEALTHY 1032 MB HIGH NEAR 34N140W AND LOW PRES OVER THE ROCKIES 
IS PRODUCING 20-25 KT NLY WINDS N OF 26N E OF 126W. WINDS WAVES 
AND NWLY SWELL WITH INCREASE SEAS TO 13 FT ACROSS THE EXTREME 
N/NE PORTION IN 24 HOURS. WINDS AND SEAS WILL RELAX THEREAFTER 
AS THE PRES GRAD LOOSENS.

TROPICS...
A SPRAWLING UPPER HIGH STRETCHES ACROSS THE BULK OF THE AREA 
CENTERED NEAR 9N112W. WEAK INVERTED UPPER TROUGHING LIES ABOVE 
THE W PORTION WITH A ROUGH AXIS ALONG 20N138W 3N132W. ABUNDANT 
HIGH LEVEL CLOUDINESS APPEARS LOCKED IN THE RIDGE CIRCULATION 
BASED ON WV IMAGES. A FEW CLUSTERS OF MODERATE CONVECTION HAVE 
DEVELOPED IN THE UPPER RIDGE MOSTLY ALIGNED ALONG THE ITCZ AXIS. 
THE MOST NOTABLE CLUSTER...SOMEWHAT DETACHED FROM THE ITCZ...IS 
FROM 6N-11N BETWEEN 112W-120W. THIS ACTIVITY IS BEING ENHANCED 
BY A SFC TROUGH DEPICTED WELL BY LAST NIGHT'S QSCAT PASS. THE 
FIRST COUPLE VIS AND A LONGER LOOP OF SW IR IMAGES SHOW SOME 
CYCLONIC TURNING ALONG THE TROUGH AXIS WITH A MID-LEVEL 
CIRCULATION CENTER EVIDENT NEAR 6N117W. OTHERWISE...THE SFC 
PATTERN IS A TYPICAL ONE WITH A STRONG SUBTROPICAL HIGH 
POSITIONED NEAR 34N140W. THIS HIGH IS PRODUCING NE TRADES MOSTLY 
NEAR 20 KT...BUT LEFT 20-25 KT IN THE CURRENT HIGH SEAS DUE TO A 
SHIP REPORT OR TWO...FROM 10N-24N W OF 128W. THESE WINDS ARE 
FORECAST TO SUBSIDE BELOW 20 KT IN ABOUT 48 HOURS AS THE HIGH 
PULLS TO THE NE AND WEAKENS.

$$
CANGIALOSI