000
AXPZ20 KNHC 070957 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON DEC 07 2009

CORRECTED FOR DATE/TIME

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE...AXIS ANALYZED ALONG 05N77W 
TO 09N86W TO 07N102W TO 10N109W...THEN RESUMES FROM 09N114W TO 
08N125W THEN FROM 08N128W TO 07N140W. WIDELY SCATTERED MODERATE 
CONVECTION IS FROM 08N TO 11N BETWEEN 117W TO 121W.

...DISCUSSION...
GLOBAL MODELS ARE INDICATING AN ACTIVE AND ENERGETIC UPPER LEVEL 
SOUTHERN STREAM FLOW INTO CALIFORNIA...THE NORTHERN HALF OF 
MEXICO...AND THE DESERT SW OF THE U.S. OVER THE NEXT SEVERAL 
DAYS THAT WILL SKIRT N OF 25N ACROSS A PORTION OF THE HIGH SEAS 
WATERS. CURRENTLY...AN UPPER LOW REMAINS OVER THE PACIFIC NW 
CONUS WITH A SHORTWAVE MID-LEVEL TROUGH ROTATING THROUGH THE 
BASE OF THIS BROAD CIRCULATION LOCATED OFFSHORE OF SOUTHERN 
CALIFORNIA. THIS PROGRESSIVE MIDDLE TO UPPER LEVEL SHORTWAVE 
EXTENDS TROUGHING SW TO 25N135W...THEN CONTINUES AS A VERY SHARP 
AND NEARLY STATIONARY TROUGH TO 08N147W CONTINUING W-SW INTO THE 
TROPICAL CENTRAL PACIFIC. AN UPPER LEVEL HIGH IS LOCATED W OF 
CENTRAL AMERICA NEAR 10N100W OVER THE TROPICAL E PACIFIC WITH 
RIDGING EXTENDING WESTWARD TO 17N132W...NW OF THE PREVIOUSLY 
MENTIONED SHARP UPPER TROUGH NEAR THE WESTERN EXTENT OF THE  
DISCUSSION AREA. STRONG UPPER LEVEL SW TO WESTERLY FLOW IS NOTED 
ON WATER VAPOR IMAGERY SE AND E OF THIS TROUGH AND ACROSS THE 
NORTHERN HIGH SEAS WATERS AND MEXICO. 

THE TROUGH ENTERING W PORTIONS OF THE AREA IS SUPPORTING A COLD 
FRONT EXTENDING FROM 30N130W TO 26N140W...AND REMAINS THE 
LEADING EDGE OF ANOTHER PULSE OF LARGE NW SWELL. THE SHORTWAVE 
ENERGY ASSOCIATED WITH THIS TROUGH WILL PASS NORTH OF A SURFACE 
RIDGE THAT WILL SHIFT WESTWARD IN 24 HOURS AS THE SHORTWAVE 
BECOMES ABSORBED IN THE MEAN TROUGH OVER THE PACIFIC NW AND 
REORGANIZE AS IT MOVES EASTWARD OVER THE DESERT SW CONUS. THE 
PASSAGE OF THIS WAVE OF ENERGY ACROSS THE UPPER RIDGE WILL HELP 
TO INHIBIT ANY DEEP LAYER RIDGING FROM TAKING HOLD AT THE 
SURFACE ACROSS NORTH WATERS...THUS REDUCING THE AREA OF NE TO 
ELY TRADE WINDS TO LESS THAN 20 KT DURING THE NEXT FEW DAYS. THE 
COLD FRONT IS FORECAST TO TRANSLATE EASTWARD RELATIVELY QUICKLY 
ACROSS SOUTHERN CALIFORNIA...APPROACHING THE NORTHERN BAJA 
PENINSULA LATE MONDAY...ACCOMPANIED BY NWLY SWELL WITH SEAS 
FORECAST 9 TO 11 FT ACROSS NE PORTIONS. THE SURFACE REFLECTION 
OF THIS DEEP LAYERED LOW IS EXPECTED TO DEEPEN AS IT MOVES 
ACROSS SOUTHERN NEVADA...PRODUCING A TIGHT PRESSURE GRADIENT 
ACROSS THE NE WATERS AND OVER THE NORTHERN GULF OF CALIFORNIA. 
THIS WILL INDUCE A BRIEF PERIOD OF WINDS TO 30 KT IN THE GULF 
MONDAY NIGHT THROUGH TUESDAY MORNING. 

MEANWHILE...A NEW FRONT WILL APPROACH THE NW WATERS BY EARLY 
TUESDAY AND BRING A NEW PULSE OF NW SWELL WITH SEAS RISING TO 20 
FT W OF THE FRONT.

S OF 20N...TWO LOW PRESSURE SYSTEMS ARE EMBEDDED WITHIN THE 
ITCZ. THE 1011 MB SURFACE LOW NEAR 09N126W HAS SCATTERED SHOWERS 
FOUND WITHIN 120 NM OF THE LOW CENTER. THIS LOW IS MOVING INTO A 
REGION OF STRONGER UPPER WINDS FROM THE SW THAT WILL LIMIT ANY 
FURTHER DEVELOPMENT OF THE LOW. A SECOND SURFACE LOW LIES NEAR 
11N111W. THIS 1010 MB LOW HAS SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION WITHIN 300 NM WESTERN SEMICIRCLE. THIS LOW 
LIES BENEATH THE RIDGE AXIS...WHICH CONTINUES TO ENHANCE ITCZ 
CONVECTION VERY WELL TO THE W OF THE LOW TO 121W. THIS SYSTEM IS 
MORE LIKELY TO SURVIVE THE NEXT FEW DAYS AS IT REMAINS IN A 
REGION OF UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL 
RIDGE AXIS. EXPECT SHOWERS AND THUNDERSTORMS TO CONTINUE IN THIS 
TROPICAL REGION W OF THE LOW FOR THE NEXT DAY OR TWO AS THE 
UPPER LEVEL WIND SHEAR REMAINS RELATIVELY LOW.

GAP WINDS...
GULF OF PAPAGAYO...EXPECT ELY WINDS TO PULSE UP AND DOWN THROUGH 
THE GULF OF PAPAGAYO AND THEN DOWNSTREAM TO NEAR 91W THROUGH TUE 
MORNING. THESE WINDS WILL BE STRONGEST...20 TO 25 KT...IN THE 
MORNING HOURS WITH THE AID OF DRAINAGE FLOW. THESE WINDS ARE 
EXPECTED TO DIMINISH BELOW 20 KT BY WED MORNING.

$$
HUFFMAN