000
AXPZ20 KNHC 071536
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAR 07 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
ITCZ AXIS ALONG 3N78W 2N97W 8N130W 5N140W. SCATTERED MODERATE 
ISOLATED STRONG WITHIN 180 NM N OF AXIS FROM 115W TO 124W.

...DISCUSSION...

EAST OF 110W...
MAIN ISSUE THROUGH SAT IS GALE FORCE WINDS THROUGH THE GULF OF 
TEHUANTEPEC.  A STRONG COLD FRONT IS MOVING S THROUGH THE GULF 
OF MEXICO...BRINGING GALES TO THE WESTERN AND CENTRAL GULF OF 
MEXICO. 1026 MB SURFACE HIGH PRES CENTERED OVER NRN MEXICO WILL 
SHIFT SE INTO THE SW GULF OF MEXICO TODAY...TIGHTENING THE 
PRESSURE GRADIENT IN THE TEHUANTEPEC ISTHMUS. GALE FORCE WINDS 
WILL COMMENCE LATE EVENING AND PERSIST THROUGH SAT. THE SURFACE 
HIGH PRES DRIVING THE EVENT WILL SHIFT EWD BY LATE 
SAT...ALLOWING THE PRES GRADIENT TO RELAX AND ALLOWING MODERATE 
SELY RETURN FLOW OVER THE WRN GULF OF MEXICO. THIS WILL ALLOW 
PERMIT NLY GAP WINDS THROUGH TEHUANTEPEC TO DIMINISH THROUGH SUN

ELSEWHERE E OF 110W...A TIGHT GRADIENT ON THE EASTERN SIDE OF 
THE HIGH PRES IS ALLOWING FRESH TO STRONG NLY FLOW OVER THE 
SOUTHERN GULF OF CALIFORNIA...AS DEPICTED BY SCATTEROMETER AND 
SHIP OBSERVATIONS. THESE WINDS WILL DIMINISH THROUGH SAT AS THE 
HIGH PRES SHIFTS E. HIGH PRES W OF BAJA WILL SHIFT EWD 
SAT...ALLOWING MODERATE TO FRESH NLY FLOW OFF THE WRN COAST OF 
BAJA. ALOFT...A MID/UPPER TROUGH IS DIGGING THROUGH TEXAS...N OF 
A BROAD UPPER ANTICYCLONE CENTERED OVER THE SW CARIBBEAN. 
DIVERGENCE ALOFT ON THE SW SIDE OF THE UPPER ANTICYCLONE IS 
INTERACTING WITH LOW LEVEL CONVERGENCE ALONG THE ITCZ TO PROMOTE 
MODEST CONVECTION AS DESCRIBED ABOVE. WATER VAPOR IMAGERY SHOWS 
A WEAK SHORT WAVE TROUGH DIGGING INTO NORTHERN BAJA...BUT WILL 
HAVE LITTLE IMPACT ON SENSIBLE SURFACE WEATHER. FURTHER 
SOUTH...ELY TRADES OVER THE SW CARIBBEAN WILL PICK UP SAT INTO 
SUN AS HIGH PRES BUILDS N OF THE CARIBBEAN. THIS WILL IN TURN 
ALLOW FRESH TO STRONG ELY FLOW THROUGH GULF OF PAPAGAYO...AND 
FRESH NLY FLOW THROUGH GULF OF PANAMA BY EARLY SUN.

W OF 110W...
A WEAK MID/UPPER SHORTWAVE TROUGH ORIENTED NE TO SW 
IS DIGGING THROUGH ROUGHLY 125W N OF 25N...CUTTING OFF AN UPPER 
LOW E OF HAWAII NEAR 19N142W. MEANWHILE SMALL UPPER RIDGE IS 
CENTERED NEAR 11N118W. THE RESULTING MID/UPPER SW FLOW BETWEEN 
THE UPPER RIDGE AND THE TROUGHING TO THE N IS ADVECTING DEEP 
LAYER MOISTURE NWD AND ALLOWING WEAK SHOWERS ALONG 25N BETWEEN 
120W AND 130W. DIVERGENCE ALOFT ON THE SRN EDGE OF THE UPPER 
RIDGE IS ENHANCING CONVECTION ALONG THE ITCZ AS DESCRIBED ABOVE. 
THE UPPER DIVERGENCE IS ALSO SUSTAINING A WEAK TROUGH ALONG THE 
ITCZ NEAR 135W. THE GRADIENT BETWEEN THE TROUGH AND SURFACE 
RIDGING WELL TO THE N IS MAINTAINING A BROAD AREA OF FRESH TRADE 
WINDS ROUGHLY BETWEEN 7N AND 20N W OF 120W.

$$
CHRISTENSEN