000
AXPZ20 KNHC 040924
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN FEB 04 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 ALONG 3N77W 3N85W 5N101W 5N120W 5N130W 7N140W. 
ISOLATED MODERATE CONVECTION NEAR 6N134W. 

...DISCUSSION...

MID LEVEL FEATURES GAINING MORE AMPLITUDE TONIGHT WITH MOVEMENT 
OF COLD AIR SWD. ON AREA IS WITH A SHORTWAVE TROUGH SE OF BAJA 
ALONG 108W. THIS SYSTEM STILL GETS COLD AIR FROM OVER THE WRN 
CONUS BUT A MID LEVEL RIDGE ALONG 123W CONTINUES TO MOVE SLOWLY 
EWD AND IS BEGINNING TO CUTOFF THE SOURCE OF COLD AIR. FURTHER W 
TONIGHT A SHARP AMPLITUDE TROUGH HAS SHIFTED TO 140W PUSHED BY A 
STRONG JET SEGMENT ON IT'S W SIDE. AN EQUALLY STRONG JET SEGMENT 
EXITS ALONG THE E SIDE OF THE TROUGH WITH AN IMPRESSIVE FLOW OF 
MID AND HIGH LEVEL MOISTURE ALONG 140W NW. ON THE SURFACE 
TONIGHT A 1002 MB LOW WAS JUST NW OF THE REGION ASSOCIATED WITH 
THE SHARP TROUGH. A COLD FRONT EXTENDS FROM THE LOW SSE JUST 
INSIDE OUR WRN BORDER. THE FRONT IS PACKING THE GRADIENT 
RESULTING IN GALE CONDITIONS N OF 23N WITHIN 120 NM E OF THE 
FRONT. THE PACIFIC RIDGE HAS BEEN SLOWLY WEAKENING AND LIES 
ALONG 122W. NE TRADES ARE CONFINED TO 6N TO 20N BETWEEN 110W AND 
130W WHERE QUIKSCAT AND SSMI SHOW WINDS 20 TO 25 KT. SEA OF 
CORTEZ WINDS HAVE ALSO INCREASED WITH BOTH MICROWAVE IMAGERY 
SHOWING 20 TO 25 KT TONIGHT WHILE W OF THE BAJA PENINSULA NW 
WINDS ARE 15 TO 20 KT. WINDS THROUGH TEHUANTEPEC HAVE BEGUN TO 
BLOW WITH NO MICROWAVE IMAGERY TONIGHT BUT A SHIP SHOWING 20 KT 
WHILE THE GFS MODEL SHOWS 25 KT. A GALE CONDITION IS EXPECTED BY 
18Z. ALSO GAP WINDS W OF NICARAGUA AND EL SALVADOR ARE ALSO 
BLOWING 20 TO 25 KT ACCORDING TO IMAGERY. GULF OF PANAMA WINDS N 
TO NE AT 20 KT.

LATER DAY 1 THE SHORTWAVE TROUGH SE OF BAJA SHOWS MORE SIGNS OF 
CUTTING OFF AS THE MID LEVEL RIDGE MOVES TO 120W AND CONTINUES 
SLOWLY CUTTING OFF THE COLD AIR SOURCE. FURTHER W THE SHARP 
TROUGH BECOMES MORE NEGATIVELY TILTED RESULTING IN STRONG COLD 
AIR ADVECTION N OF 20N W OF 125W. ON THE SURFACE LATER DAY 1 A 
1006 MB LOW WILL MOVE SLOWLY NE BY THE NW CORNER OF THE REGION 
WITH A COLD FRONT SWINGING E ALONG 134W. GALE CONDITIONS WILL 
CONTINUE E OF THE FRONT. W OF THE FRONT WINDS BECOME WLY BUT 
REMAIN GUSTY AT 20 TO 30 KT WITH WLY SWELL OF 11 TO 16 FT. THE 
PACIFIC RIDGE ALONG 122W WILL MAINTAIN NE TRADES 20 TO 25 KT 
BETWEEN 7N AND 15N W OF 125W. WINDS ALONG THE BAJA COAST WILL 
DECREASE TO 10 TO 15 KT FROM THE NE. SEA OF CORTEZ WINDS WEAKEN 
TO 10 TO 15 KT. TEHUANTEPEC WINDS WILL STAY IN THE 20 TO 25 KT 
RANGE WITH SEAS TO 9 FT. GAP WINDS ELSEWHERE CHANGE LITTLE.

FOR DAY 2 A WEAKENING SHORTWAVE TROUGH WILL LIMP EWD ALONG 105W 
EFFECTIVELY CUTOFF FROM THE MAIN STREAM NWLY FLOW OVER THE 
CONUS. THE MID LEVEL RIDGE ALSO WEAKENS AS IT DRIFTS TO 115W. 
THE NEGATIVELY TILTED TROUGH OVER THE NW PORTION MOVES TO 130W 
BUT IT TOO GETS CUTOFF FROM IT'S COLD SOURCE TO THE NW AS THE 
MID LEVEL FLOW TURNS MORE WLY S OF 34N. ON THE SURFACE DAY 2 THE 
LOW JUST NW OF THE REGION WEAKENS AS IT'S UPPER SUPPORT WEAKENS. 
A COLD FRONT FROM THE LOW SWINGS E TO 130W BUT ALSO DIES OUT AS 
THE WLY FLOW BEHIND THE FRONT BECOMES MORE MILD. WHILE WINDS 
WEAKEN WITH THIS SYSTEM..WLY SWELL OF 12 TO 14 FT WILL CONTINUE. 
THE PACIFIC RIDGE REMAINS ALONG 120W WITH A 1020 MB CENTER. NE 
TRADES DIMINISH WITH STRONGEST WINDS W OF 130W. GALE CONDITIONS 
ARE EXPECTED TO CONTINUE THROUGH TEHUANTEPEC WITH SEAS 9 TO 12 
FT. OTHER GAP WINDS REMAIN ABOUT THE SAME. 

$$
RRG