000
AXPZ20 KNHC 291608
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN NOV 29 2009

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...
AXIS ANALYZED ALONG 07N77W TO 06N80W TO 08N105W TO 08N115W TO 
12N124W TO 10N130W TO 09N140W.  SCATTERED MODERATE CONVECTION 
WAS WITHIN 120 NM OF AXIS E OF 101W AND WITHIN 60 NM OF AXIS 
FROM 124W TO 130W.

...DISCUSSION...
LARGE OMEGA BLOCKING PATTERN SPANS THE HIGHER LATITUDES OF THE 
CENTRAL AND NE PACIFIC...WITH STRONG SRN STREAM UPPER LEVEL WLYS 
THIS MORNING UNDERCUTTING THIS PATTERN...FROM 15N TO 25N BETWEEN 
145W TO 120W. A VIGOROUS AND DEEP LAYERED LOW WAS SINKING VERY 
SLOWLY S ACROSS SRN CALIFORNIA-ARIZONA-EXTREME NW MEXICO THIS 
MORNING...AND WAS THE SW EXTENSION OF THE ERN TROUGH OF THE 
OMEGA BLOCK. UPPER LEVEL WLYS SPLIT S OF THIS DEEP LAYERED 
LOW...WITH A JET OF 90-125 KT MOVING ENE ACROSS THE S HALF OF 
THE BAJA PENINSULA AND ACROSS THE SIERRA MADRE OCCIDENTALES OF 
MEXICO...IGNITING ELEVATED CONVECTION ACROSS THE RIDGE AND 
LEEWARD SLOPES OF THE MOUNTAINS. THE S PORTION OF THE EQUATORIAL 
WLY FLOW ALOFT WAS BEING DIVERTED SE INTO THE BACKSIDE OF A LOW 
TO MID LEVEL TROUGH EXTENDING FROM THE YUCATAN PENINSULA TO A 
WEAK UPPER LOW ALONG THE ITCZ NEAR 09N106W. UPPER RIDGING TO THE 
E OF THIS TROUGH WAS VENTING SCATTERED MODERATE CONVECTION ALONG 
THE ITCZ E OF 101W INTO S AMERICA. 

THIS DEEP LAYERED LOW ACROSS THE DESERT SW IS FORECAST TO DRIFT 
SE TOWARDS W TEXAS OVER THE NEXT FEW DAYS...WITH UPPER RIDGING 
TO THE W AMPLIFYING IN RESPONSE TO A DIGGING UPPER TROUGH TO ITS 
W. THIS DEEP LAYERED LOW CURRENTLY SUPPORTS A PAIR OF SURFACE 
LOWS ACROSS ARIZONA...WITH AN OLD COLD FRONTAL BOUNDARY 
EXTENDING FROM NW MEXICO ACROSS SRN BAJA THEN CONTINUING WSW 
THEN W AS A SHEAR LINE TO 19N129W. CONTINUED COLD AIR ADVECTION 
AND GOOD PRESSURE GRADIENT BETWEEN THESE BOUNDARIES AND A 1030 
MB HIGH OVER THE NE PACIFIC ARE MAINTAINING FRESH TRADES BEHIND 
THE SHEAR LINE...EXTENDING S TO THE ITCZ W OF 125W. MEANWHILE A 
SECONDARY SURGE OF COOLER VERY DRY AIR...WITH UPSTREAM NLY FLOW 
TO NEAR GALES ALONG THE N AND CENTRAL CALIFORNIA COASTS PUSHING 
A BENIGN FRONTAL BOUNDARY S ACROSS THE FAR NE WATERS AND NRN 
BAJA CALIFORNIA. W TO NW FLOW WITH THIS FEATURE...AND BEHIND THE 
FIRST FRONTAL BOUNDARY WERE PRODUCING AREAS OF 20-25 KT WINDS 
ACROSS THE N HALF OF THE GULF OF CALIFORNIA. AS THE DEEP LAYERED 
LOW MOVES SE OVER THE NEXT FEW DAYS...THE GRADIENT ACROSS THE 
REGION WILL GRADUALLY DIMINISH...ALLOWING FRESH TRADES TO SHRINK 
AND BECOME CONFINED TO S OF 20-21N...WITH NLY FLOW AROUND 20 KT 
LIKELY TO PERSIST ALONG BOTH SIDES OF THE BAJA PENINSULA.   

LARGE LONG PERIOD SWELL YIELDING SEAS UP TO 18 FT CONTINUES OF 
PROPAGATE SE AND S THROUGH THE NRN WATERS REACHING EQUATOR AND 
BEYOND.  SEAS HEIGHTS ARE FORECAST TO PEAK DURING NEXT 24 HRS 
THEN SUBSIDE MON. 

...GAP WINDS...
NLY WINDS THROUGH THE GULF OF TEHUANTEPEC WERE STILL BLOWING 
20-25 KT OVERNIGHT AS DEPICTED BY AN ASCAT PASS BUT WILL DROP 
OFF TO BELOW 20 KT WITHIN 12 HOURS AS SLY RETURN FLOW HAS BECOME 
ESTABLISHED ACROSS THE W GULF OF MEXICO. ELY TRADES IN W 
CARIBBEAN CONTINUE TO FUNNEL WINDS THROUGH GULF OF PAPAGAYO AND 
DOWNSTREAM WATERS TO 90W...AND WILL PULSE UP AND DOWN THROUGH 
MON.

$$
STRIPLING