000
AXPZ20 KNHC 161600
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 16 2007

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 
1515 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N77W 8N100W 9N120W 6N140W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OFF THE 
COLOMBIAN AND PANAMA COAST WITHIN 90NM EITHER SIDE OF THE AXIS E 
OF 83W...AND WITHIN 90NM EITHER SIDE BETWEEN 106W-113W. 
SCATTERED MODERATE WITHIN 60NM N AND 90NM S OF AXIS BETWEEN 
127W-131W.

...DISCUSSION...
UPPER LEVELS...
A W TO SWLY JET BRANCH WITH CORE WINDS NEAR 70 KT ORIGINATES 
NEAR 19N130W AND EXTENDS ENE ALONG 25N120W TO CENTRAL BAJA 
CALIFORNIA. UPPER CONFLUENCE TO THE N OF THE JET AXIS IS HELPING 
TO SINK AND STABILIZE THE ATMOSPHERE ACROSS A GOOD PORTION OF 
THE SUBTROPICS. UPPER DIFFLUENCE AND MOIST S-SWLY FLOW S OF THE 
JET AXIS IS DRAWING MOISTURE FROM THE ITCZ AND ADVECTING IT 
TOWARD THE MEXICAN COAST GENERALLY BETWEEN 105W-125W. MOST OF 
THIS MOISTURE IS ONLY IN THE FORM OF A MID-HIGH LEVEL CLOUD DECK 
ALTHOUGH THERE COULD BE ISOLATED TO SCATTERED SHOWERS FROM THE 
ITCZ TO 17N BETWEEN 115W-122W. FARTHER E...BROAD FLAT UPPER 
RIDGING...ANCHORED OVER NRN SOUTH AMERICA...EXTENDS W FEEDING 
INTO THE MENTIONED JET. FAIRLY STABLE AIR PROVIDED BY THE RIDGE 
E OF 100W IS HELPING TO LIMIT CONVECTION ALONG THE ITCZ WHILE 
DIFFLUENCE S OF THE JET IS FUELING MODERATE CONVECTION ALONG THE 
ITCZ BETWEEN 106W-113W. 

LOW LEVELS...
A STATIONARY 1026 MB HIGH CENTERED NEAR 31N134W CONTROLS THE 
PATTERN ACROSS THE REGION. THE ONLY OTHER LOW-LEVEL FEATURE 
MIGHT BE A DEVELOPING SFC TROUGH ALONG THE ITCZ NEAR 123W. NE 
TRADES ARE NEAR 20 KT ON THE SRN PERIPHERY OF THE RIDGE. A 
SIMILAR MAGNITUDE NLY SURGE IS OBSERVED ACROSS THE NE PORTION 
OF THE REGION WITH 20 KT WINDS BEING REPORTED BY SEVERAL SHIPS 
AS FAR S AS 16N. BOTH OF THESE AREAS ARE FORECAST TO WEAKEN 
SLIGHTLY OVER THE NEXT COUPLE OF DAYS.  

GAP WINDS...A 1236 UTC QSCAT PASS SHOWED 20-25 KT NLY WINDS 
ACROSS THE GULF OF TEHUANTEPEC. MODELS SHOW THIS GAP WIND EVENT 
PULSING UP AND DOWN OVER THE NEXT COUPLE OF DAYS WITH A GENERAL 
INCREASE IN PEAK WINDS SO WENT LITTLE CHANGE IN THE FORECAST 
BESIDES FOR INCREASING THE RANGE TO 20-30 KT.

$$
CANGIALOSI