000
AXPZ20 KNHC 280929
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JAN 28 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 1N79W 7N91W 5N104W 5N116W 7N134W 7N140W. 
ISOLATED MODERATE CONVECTION NEAR 4N78W AND 5N89W. OTHER 
ISOLATED MODERATE CONVECTION NEAR 10N119W AND 7N125W..OTHERWISE 
NO SIGNIFICANT CONVECTION.

...DISCUSSION...

A STRENGTHENING SRN BRANCH OF THE WESTERLIES IS EVIDENT TONIGHT 
ACROSS THE REGION BETWEEN 10N AND 30N. A FAIRLY STRONG SHORTWAVE 
TROUGH WAS ALONG 135W MOVING ESE 20 KT. A JET SEGMENT SE OF THE 
SHORTWAVE EXTENDED FROM 10N132W TO JUST SW OF BAJA WITH A LARGE 
PLUM OF MID AND HIGH CLOUDS. A CLOSED MID LEVEL VORTEX WAS 
LOCATED OFF THE SRN CA COAST JUST N OF THE REGION AND WAS MOVING 
SLOWLY INLAND. ON THE SURFACE TONIGHT A WEAK PACIFIC RIDGE 1020 
MB WAS CENTERED NEAR 26N120W. NE TRADES HAVE WEAKENED AND ARE 
LIMITED TO A SMALL AREA BETWEEN 8N AND 15N W OF 125W. SSMI AND 
QUIKSCAT SHOW 20 KT. A WEAK LOW WAS LOCATED NEAR THE NW BORDER 
AT 26N141W. WINDS TO 20 KT WERE LOCATED OVER THE NE QUADRANT 
WITHIN 150 NM OF THE CENTER. HIGH PRESSURE IS BUILDING OVER THE 
WRN GULF OF MEXICO AND WILL SOON INCREASE WINDS THROUGH 
TEHUANTEPEC. A GALE WARNING IS POSTED FOR WINDS INCREASING TO 35 
KT BY 12Z THIS MORNING. WINDS ALONG THE BAJA COAST ARE MOSTLY 
LIGHT N AND NE. OTHER GAP WINDS ARE MOSTLY LIGHT TONIGHT EXCEPT 
FOR S OF PANAMA WHERE QUIKSCAT SHOWS WINDS 20 TO 25 KT IN A 
NARROW BAND S AND SW OF THE CANAL.

LATER DAY 1 LOOK FOR THE SHORTWAVE AND CUTOFF VORTEX TO BEGIN 
INTERACTING WITH EACH OTHER BETWEEN 120W AND 130W LOWERING MID 
LEVEL HEIGHTS BETWEEN 110W AND 120W. ON THE SURFACE LATER DAY 1 
THE PACIFIC RIDGE WILL REMAIN WEAK 1021 MB JUST W OF THE UPPER 
BAJA COAST. STRONGEST NE TRADES ARE EXPECTED BETWEEN 10N AND 20N 
FROM 105W TO 125W. GALE CONDITIONS ARE EXPECTED THROUGH GULF OF 
TEHUANTEPEC WITH WIND GUSTS TO 45 KT AND SEAS BUILDING TO 13 
FT..OTHERWISE WINDS ALONG THE BAJA AND CENTRAL AMERICAN COASTS 
WILL REMAIN THE SAME.

FOR DAY 2 THE GFS MODEL SHOWS THE SHORTWAVE TROUGH CONTINUING 
EWD TO ALONG 110W WHILE THE CUTOFF VORTEX REMAINS STATIONARY 
JUST W OF THE SRN CA COAST. A STRONG MID LEVEL FLOW WILL 
CONTINUE BETWEEN 10N AND 28N ACROSS THE REGION. ON THE SURFACE 
DAY 2 A WEAK PACIFIC RIDGE WILL CONTINUE ALONG 24N. NE TRADES OF 
20 TO 25 KT ARE FORECAST WITHIN 400 NM NW OF A LINE FROM 18N105W 
TO 8N125W. GALE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 
TEHUANTEPEC WITH A MODERATE HIGH SITTING OVER THE GULF OF 
MEXICO. WINDS SHOULD DIMINISH LATE DAY 2.  THE AREA W OF 
NICARAGUA AND EL SALVADOR WILL SEE WINDS INCREASE 20 TO 25 KT 
WITH SEAS TO 8 FT AS HIGH PRESSURE BUILDS OVER THE CARIBBEAN.

$$
RRG