000
AXPZ20 KNHC 180922
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN FEB 18 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 4N77W 5N85W 2N95W 7N122W 3N140W. CLUSTER OF 
MODERATE TO STRONG CONVECTION WITHIN 60 NM OF 4N87W. ISOLATED 
MODERATE NEAR 1N89W 3N89W AND 3N91W. SCATTERED MODERATE WITHIN 
20 NM OF A LINE FROM 6N111W TO 8N115W TO 7N120W TO 7N127W. 
ISOLATED MODERATE NEAR 6N134W AND 3N139W. 

...DISCUSSION...

IN THE MID LEVELS TONIGHT..WHATS LEFT OF A CUTOFF LOW IS NEAR 
30N120W MOVING SLOWLY N. A FAIRLY STRONG SHORTWAVE TROUGH IS 
DIVING SE ALONG 130W JUST N OF THE REGION AND IS HELPING LIFT 
THE CUTOFF OUT OF OUR REGION. A MID LEVEL RIDGE IS BUILDING 
AHEAD OF THE CUTOFF ALONG 105W OVER MEXICO. W OF 130W THE MID 
LEVEL FLOW TURNS NWLY WITH COLDER AIR ALOFT MOVING INTO OUR 
REGION. A SUBTROPIC JET ALONG 20N140W HEADS ENE ACROSS S CENTRAL 
BAJA. ON THE SURFACE TONIGHT A WEAK LOW CENTER IS MOVING NE JUST 
ABOUT UNDER THE MID LEVEL CENTER INTO NRN BAJA/S CA.  A NEW 
SURGE OF COLD AIR IS MOVING INTO THE REGION NW OF A LINE FROM 
30N122W TO 23N140W. QUIKSCAT AND SSMI SHOW N WINDS TO 25 KT. A 
GALE CONDITION IS EMINENT THROUGH TEHUANTEPEC AS LOW CLOUDS ARE 
SCENE MOVING RAPIDLY S ON THE GULF OF MEXICO SIDE.

LATER DAY 1 THE CUTOFF LOW IS FORECAST TO OPEN TO A TROUGH ALONG 
115W AS IT IS FORCED OVER THE RIDGE BY THE SHORTWAVE ALONG 125W. 
SOME MID LEVEL TROUGHING WILL CONTINUE SW TO 20N140W WITH THE 
STRONG NWLY FLOW CONTINUING N OF 20N W OF 125W. ON THE SURFACE 
LATER DAY 1 STRONG N AND NE WINDS WILL CONTINUE W OF 125W WITH 
SEAS 9 TO 12 FT AS A FAIRLY STRONG PACIFIC RIDGE REMAINS BACK NW 
OF THE AREA NEAR 35N145W. WINDS ALONG THE BAJA COAST WILL REMAIN 
LIGHT SW TO W DUE TO A WEAK PRESSURE GRADIENT. STRONG GUSTY N 
WINDS OF GALE FORCE WILL CONTINUE THROUGH TEHUANTEPEC WITH 
POSSIBLE GUSTS TO STORM FORCE..50 KT. SEAS WILL INCREASE TO 15 
FT. OTHER GAP AREAS W OF CENTRAL AMERICA WILL BEGIN TO 
EXPERIENCE STRONG GUSTY N AND NE WINDS AS HIGH PRESSURE BUILDS 
OVER THE NW CARIBBEAN.

FOR DAY 2 LOOK FOR THE STRONG SHORTWAVE TROUGH TO MOVE TO 120W 
WITH A VERY STRONG MID LEVEL FLOW DEVELOPING E OF 120W N OF 20N. 
W OF 120W THE MID LEVEL FLOW WILL REMAIN NWLY WITH A MID LEVEL 
HIGH CENTER MOVING E TO NEAR 30N145W. ON THE SURFACE DAY 2 THE 
STRONG N AND NE WINDS OVER THE PACIFIC W OF 120W WILL CONTINUE 
WITH SEAS OF 9 TO 14 FT. WINDS ALONG THE BAJA COAST WILL 
INCREASE FROM THE NW AT 15 TO 20 KT WITH SEAS BUILDING TO 12 FT 
OVER THE EXTREME NW CORNER. MOVEMENT OF HIGH PRESSURE OVER THE 
NE GULF OF MEXICO WILL LESSEN THE GRADIENT THROUGH TEHUANTEPEC 
AND WINDS ARE EXPECTED TO DROP BELOW GALE FORCE LATE DAY 2. NW 
SWELL TO 12 FT WILL PERSIST BETWEEN 8N AND 14N E OF 105W. OTHER 
GAP WINDS W OF NICARAGUA AND EL SALVADOR WILL INCREASE 25 TO 30 
KT WITH POSSIBLE GUSTS TO GALE FORCE WITH SEAS ALSO INCREASING 
TO 12 FT. N WINDS THROUGH THE GULF OF PANAMA WILL ALSO INCREASE 
TO 20 TO 25 KT AS HIGH PRESSURE CONTINUES OVER THE WRN 
CARIBBEAN. 

$$
RRG