000
AXPZ20 KNHC 130915
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE MAR 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N78W 6N83W 3N99W 4N110W 2N133W 
3N140W. SCATTERED MODERATE CONVECTION WITHIN 45 NM OF 
5N90W...AND WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 102W 
AND 107W. 

...DISCUSSION...
HIGHLY AMPLIFIED PATTERN OVER THE EPAC FORECAST AREA THIS 
MORNING. MID/UPPER LEVEL LOW PRES IS WELL DEFINED ON WATER VAPOR 
IMAGERY NEAR 26N137W...WITH ASSOCIATED TROUGH FROM 30N138W TO 
17N138W...MOVING EWD AT 15 KT AHEAD OF RIDGE BUILDING NE OF 
HAWAII. SHIP OBSERVATIONS SHOW 20 KT NE FLOW TO THE E OF THE 
UPPER FEATURE. WHILE THERE IS CURRENTLY NO GOOD INDICATION IN 
THE SHIP OBSERVATIONS OF A SURFACE REFLECTION OF THE MID/UPPER 
TROUGH...SOME CYCLONIC TURNING IS NOTED IN THE LOW TO MID LEVEL 
CLOUDS NEAR 22N123W...HINTING THAT A SURFACE TROUGH MAY BE 
FORMING. THE RESULTANT TIGHTENING GRADIENT WOULD ACCOUNT FOR THE 
FRESH NELY FLOW NOTED IN THE SHIP OBSERVATIONS.  

FURTHER E TOWARD THE COAST...ANOTHER MID/UPPER RIDGE SITUATED 
OFF CALIFORNIA AND BAJA COAST ALONG 120W BETWEEN AFOREMENTIONED 
TROUGH TO W AND A DEEP CUTOFF UPPER LOW OVER ERN NEW MEXICO. 
MEANWHILE TO THE S...UPPER LEVEL 60-70 KT JET ADVECTING UPPER 
LEVEL MOISTURE PLUME FROM 5N136W THROUGH CENTRAL MEXICO. 

E OF 100W...UPPER LEVEL ANTICYCLONE NEAR 7N89W IS ENHANCING 
SATELLITE CONVECTION ALONG THE ITCZ NEAR 4N87W.

GULF OF TEHUANTEPEC...NAM MODEL IS INDICATING POTENTIAL FOR 20 
TO 25 KT GAP WIND FLOW TODAY...DIMINISHING TONIGHT. EVENING SHIP 
OBSERVATIONS OVER THE SRN GULF OF MEXICO AND NW CARIBBEAN SHOW 
20 TO 30 KT FLOW...DUE TO A TIGHT GRADIENT BETWEEN HIGH PRES TO 
THE N AND A POSSIBLE SUBTLE WEAK TROUGH IN THE WRN CARIBBEAN. 
NET EFFECT WILL BE POTENTIAL HIGH MOMENTUM WINDS REFRACTING 
THROUGH TEHUANTEPEC ISTHMUS TODAY...RENDERING THE 20 TO 25 KT.

GULF OF PAPAGAYO...COSTA RICAN SURFACE OBSERVATIONS SHOW 
PERSISTENT MODERATE TO FRESH ELY WINDS...AND EARLIER GUSTS 
INDICATE BOUNDARY LAYER FLOW MAY STILL BE FAIRLY STRONG. THUS 
EXPECT FRESH TO STRONG ELY THROUGH THE GULF   

$$
CHRISTENSEN