000
AXPZ20 KNHC 231617
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAR 23 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 1545 UTC.

...ITCZ...

ITCZ IS CENTERED ALONG 4N77W 8N110W 7N120W 4N130W 
3N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N AND 30 
NM S OF AXIS BETWEEN 85W-89W AND BETWEEN 106W-112W. SIMILAR 
CONVECTION IS WITHIN 150 NM N/30 NM S OF AXIS BETWEEN 
114W-122W...AND WITHIN 60 NM EITHER SIDE BETWEEN 125W-130W AND 
BETWEEN 135W-138W. 

...DISCUSSION...

UPPER LEVELS...
NW FLOW AROUND RIDGING DOMINATES MUCH OF THE NW PORTION OF THE 
DISCUSSION AREA...N OF 22N AND W OF 125W. UPPER CONFLUENCE 
BETWEEN THE RIDGING OFF THE WRN U.S. AND THE RIDGING EXTENDING N 
FROM THE DEEP TROPICS IS SUPPORTING THE BAND OF DRY/STABLE AIR 
NOTED FROM 20N-27N W OF 125W. MOISTURE ORIGINATING IN THE UPPER 
DIFFLUENT ZONE AHEAD OF THE UPPER LOW JUST S OF THE BIG ISLAND 
IS STREAMING OVER THE AREA S OF 20N. PRONOUNCED UPPER LOW 
REMAINS NEAR THE MEX/ARIZONA BORDER THAT HAS TROUGHING EXTENDING 
S TO NEAR 15N115W. AHEAD OF THIS TROUGH LIES A RIDGE THAT 
EXTENDS NE INTO THE WRN GULF OF MEXICO. DIFFLUENT ZONE BETWEEN 
THESE FEATURES IS SUPPORTING THE MOISTURE STREAMING NE THROUGH 
CENTRAL MEXICO AND ERN TEXAS. ASIDE FOR MOISTURE OVER THE ITCZ 
CONVECTION...VERY DRY/STABLE AIR EXISTS IN THE FAR NE PAC WITH  
TROUGHING EXTENDING THROUGH CENTRAL AMERICA FROM THE NW CARIB. 

AT THE SFC...
MODERATE TO FRESH TRADE FLOW DOMINATES MUCH OF THE AREA W OF 120 
W AROUND A 1032 MB HIGH LOCATED NEAR 33N139W...WITH THE 
STRONGEST TRADES GENERALLY BETWEEN 5N-120N. ONLY SUBTLE CHANGES 
EXPECTED IN THIS REGIME THROUGH THE WEEKEND...THOUGH LONGER 
RANGE GUIDANCE SUGGESTS A STRONGER SURGE OF N TO NE WINDS AND NW 
SWELL BEHIND A FRONT EARLY TO MID NEXT WEEK. 

GAP WINDS...
QUIKSCAT PASS SHOWED A SMALL REGION OF NLY WINDS 20 TO 30 KT IN 
THE GULF OF TEHUANTEPEC THIS MORNING. NAM SEEMED TO INITIALIZE 
THIS AREA THE BEST SO HAVE OPTED WITH THAT SOLUTION. THIS WILL 
PULSE EARLY MORNING TO MID AFTERNOON OVER THE NEXT COUPLE OF 
DAYS WITH DIURNAL INFLUENCES...AND THEN RELAX INTO THE EARLY 
EVENING HOURS. HAVE OPTED WITH A GENERALIZED/BROADBRUSH APPROACH 
TO THIS DAILY VARIATION IN THE HIGH SEAS FORECAST...THUS HAVE 
ONLY GONE 20-25 KT IN THE FORECAST. SIMILAR WINDS/SEAS 
ANTICIPATED IN THE PAPAGAYO REGION OVER THE NEXT 48 HOURS.  

$$
WILLIS