000
AXPZ20 KNHC 171529
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 17 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N77W 10N99W 7N110W 6N120W 8N140W. 
NUMEROUS STRONG CONVECTION WITHIN 120 NM OF AXIS BETWEEN 78W-86W. 
SCATTERED MODERATE/STRONG WITHIN 120 NM OF AXIS BETWEEN 90W-110W. 
SCATTERED MODERATE FROM 6N-10N BETWEEN 115W-120W.

...DISCUSSION...

W OF 110W...
DEEP-LAYERED OCCLUDED LOW IS CENTERED NW OF THE AREA NEAR 33N143W 
WITH DEEP SWLY FLOW N OF 20N W OF 130W. A COLD FRONT IS JUST 
ENTERING THE AREA ALONG 140W WITH SCATTERED SHOWERS/TSTMS WITHIN 180 
NM SE OF THE BOUNDARY. AN UPPER RIDGE IS CENTERED DOWNSTREAM ALONG 
128W THEN TRANSITIONS TO A CLOSED UPPER LOW OVER NRN BAJA CALIFORNIA 
NEAR 30N116W. MODERATE/STRONG SUBSIDENCE IS LOCATED WITHIN 500 NM 
S/SW OF THE UPPER LOW DUE TO FLOW CONFLUENCE. A LARGE UPPER HIGH IS 
CENTERED FARTHER S INTO THE TROPICS NEAR 12N128W WITH A RIDGE AXIS 
EXTENDING FROM MANZANILLO MEXICO TO 10N140W. DEEP ELY FLOW LIES S OF 
THE RIDGE AXIS TO THE EQUATOR...BUT THERE IS LITTLE UPPER SUPPORT 
FOR DEEP CONVECTION NEAR THE ITCZ.

E OF 110W...
A CUT-OFF UPPER TROUGH IS ALMOST STATIONARY FROM NEAR ACAPULCO 
MEXICO SW TO 12N110W WITH A SWATH OF MOIST UPPER LEVEL SWLYS FLOWING 
INTO SE MEXICO/NRN CENTRAL AMERICA. AN INVERTED UPPER TROUGH IS S OF 
THIS AREA FROM EQ106W TO 6N94W AND THIS IS CAUSING UPPER DIVERGENCE 
OVER THE ITCZ...ENHANCING CONVECTION BETWEEN 90W-110W. 
ADDITIONALLY...STRONG LOW-LEVEL SPEED/DIRECTIONAL CONVERGENCE IS 
OCCURRING OFF THE PANAMA/COSTA RICA COASTLINE AND IS COUPLED WITH 
DIVERGENT ELY SPLIT FLOW ALOFT TO PRODUCE A LARGE AREA OF NUMEROUS 
STRONG CONVECTION ABOUT 150 NM OFF THE COAST. A LOW-LEVEL 
CONVERGENCE LINE HAS ALSO SET UP FROM 10N107W TO 16N101W WITH 
SCATTERED SHOWERS/TSTMS WITHIN 60 NM OF THE LINE. ELSEWHERE...A 
LATE-SEASON COLD FRONT HAS MOVED ACROSS THE GULF OF MEXICO WITH HIGH 
PRES NEAR TAMPICO MEXICO...AND THIS HAS CAUSED WINDS TO INCREASE TO 
GALE FORCE OVER THE GULF OF TEHUANTEPEC. THE GRADIENT WILL RELAX 
QUICKLY TODAY WITH WINDS DECREASING BELOW GALE FORCE BY THIS 
AFTERNOON BUT REMAINING AT OR ABOVE 20 KT THROUGH FRI MORNING.    

$$
BERG