000
AXPZ20 KNHC 152137
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON NOV 15 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
AXIS ANALYZED ALONG 07N81W TO 05N87W TO LOW PRES 1012 MB NEAR 
12N112W TO 09N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 
NM S OF THE AXIS BETWEEN 106W AND 110W...AND FROM 08N TO 15N 
BETWEEN 114W AND 120W.

...DISCUSSION...
AN OMEGA BLOCKING PATTERN CONTINUES ACROSS THE DISCUSSION AREA 
FOCUSED ON A LARGE DEEP LAYERED RIDGE OVER THE NE PACIFIC WITH 
AN EXPANSIVE UPPER LEVEL ANTICYCLONE CENTERED NEAR 33N129W. A 
SHARP AND NARROW MID TO UPPER LEVEL TROUGH AXIS EXTENDS FROM THE 
SOUTHERN PLAINS NEAR THE TEXAS AND OKLAHOMA PANHANDLES SW OVER 
NW MEXICO TO A BASE OVER THE GULF OF CALIFORNIA NEAR 27N112W. AN 
IT CONTINUES WESTWARD ALONG 24N AS A SHEAR AXIS THROUGH 24N130W 
TO 27N140W. STRONG SUBSIDENCE WAS OCCURRING WITHIN AND JUST TO 
THE N OF THIS AXIS...WHILE SPEED DIVERGENCE GENERALLY PREVAILED 
WITHIN 300 NM TO THE S OF THE AXIS.  

SIGNIFICANT UPPER LEVEL SHORT WAVE ENERGY IS FORECAST BY ALL THE 
GLOBAL MODELS TO MOVE OVER THE TOP OF THE UPPER LEVEL 
RIDGE...SLOWLY ERODE AND WEAKEN THIS STRONG RIDGE BY 48 TO 72 
HOURS...DEPENDING ON THE MODEL SOLUTIONS. THIS WILL BRING ABOUT 
A SIGNIFICANT PATTERN CHANGE BY THE END OF THE WEEK. 

ANOTHER UPPER LEVEL ANTICYCLONE WAS CENTERED OVER THE W 
CARIBBEAN EAST OF THE NICARAGUA AND HONDURAS COAST...WITH AN 
ASSOCIATED RIDGE AXIS EXTENDING NW TO THE BAY OF CAMPECHE. UPPER 
LEVEL FLOW WAS TURNING TO THE W AND SW BETWEEN THE RIDGE AND 
TROUGH NOTED ABOVE GENERALLY BETWEEN 90W AND 120W. A BROAD MID 
TO UPPER LEVEL CYCLONE WAS CENTERED NEAR 06N123W WITH THE 
CIRCULATION SPANNING BOTH SIDES OF THE EQUATOR. DEEP CONVECTION 
IN THE VICINITY OF A 1012 MB SURFACE LOW NEAR 12N112W WAS 
INDUCING AND MAINTAINING DIVERGENT UPPER LEVEL FLOW TO THE NE OF 
THIS UPPER CYCLONE FROM 08N TO 15N BETWEEN 106W AND 120W. 

AT THE SURFACE...A SPRAWLING 1042 MB HIGH PRES WAS CENTERED 
UNDER THE UPPER RIDGE NEAR 41N143W WITH THE ASSOCIATED RIDGE 
AXIS EXTENDING SE INTO THE DISCUSSION AREA TO NEAR 18N112W. THE 
STRONG PRESSURE GRADIENT CREATED BETWEEN THIS LARGE HIGH AND 
LOWER PRESSURES ACROSS THE TROPICS WAS MAINTAINING FRESH NE 
TRADES OF 20 TO 25 KT GENERALLY N OF 24N AND W OF 128W...WITH 
THIS AREA BEING CAPTURED BY RECENT WINDSAT AND ASCAT PASSES 
WITHIN THE LAST FEW HOURS. NE WIND SWELL ACROSS THIS AREA WAS 
MIXING WITH LONG PERIOD NW SWELL TO PRODUCE SEAS OF 10 TO 13 
FT...AND SEAS 8 TO 10 FT ELSEWHERE N OF 20N W OF 123W. THIS 
SURFACE HIGH IS FORECAST TO WEAKEN...FLATTEN...AND SHIFT SLOWLY 
SOUTHWARD DURING THE NEXT FEW DAYS...ALLOWING THE GRADIENT 
INDUCED TRADEWINDS TO DIMINISH CONSIDERABLY. IN ADDITION...AS 
THE WIND FIELD DIMINISHES...SEAS ACROSS THE NW PORTION OF THE 
AREA WILL ALSO BEGIN A SUBSIDING TREND AS WELL...WITH A NEW 
PULSE OF LONG PERIOD NW SWELL ENTERING THE AREA BY LATE TUESDAY 
AND BECOMING THE DOMINANT WAVE ENERGY THROUGH THE END OF THE 
FORECAST PERIOD. 

A MONSOONAL CIRCULATION HAS AGAIN EVOLVED DURING THE PAST 
SEVERAL DAYS ACROSS THE SW CARIBBEAN AND FAR TROPICAL EASTERN 
PACIFIC...WITH SW TO W WINDS TO 20 KT OCCURRING N OF 03N AND E 
OF 86W. THIS FLOW IS EXPECTED TO PREVAIL THROUGH THE PERIOD WITH 
LITTLE CHANGE NOTICED IN SEVERAL OF THE GLOBAL MODELS. SEAS ARE 
EXPECTED TO REMAIN LESS THAN 8 FT.

$$
HUFFMAN