000
AXPZ20 KNHC 061625
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON OCT 06 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.

...SPECIAL FEATURES...
TROPICAL STORM NORBERT AT 14.3N 104.7W AT 06/1500 UTC OR 325 NM 
S OF MANZANILLO MEXICO MOVING W OR 280 DEG AT 7 KT.  ESTIMATED 
MINIMUM CENTRAL PRES 993 MB.  MAXIMUM SUSTAINED WIND SPEED 55 
WITH GUSTS TO 65 KT.  REFER TO LATEST NHC FORECAST/ ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC AND INTERMEDIATE 
PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP5/ WTPZ35 KNHC 
FOR MORE DETAILS.  NORBERT REMAINS A SERIOUS INTENSIFICATION 
THREAT AS EVIDENCED BY SATELLITE IMAGERY AND SCATTEROMETER WINDS.
CLOUD BANDS CONVERGING AROUND TIGHT CENTER AND OUTFLOW BECOMING 
BETTER ORGANIZED AT THE EDGE OF ANTICYCLONE NOW OVER YUCATAN 
PENINSULA.  GOOD UPPER LEVEL DIFFLUENT FLOW JUST AHEAD OF 
NORBERT IMPLIES FURTHER INTENSIFICATION WITH SOME MODEL GUIDANCE 
IMPLYING STRONGER THAN OFFICIAL FORECAST.  SOUTHWESTWARD DIGGING 
UPPER LEVEL TROUGH COULD INFLUENCE NORBERT INTO A MORE NW TRACK 
...AND COOLER WATERS...BUT MOST GUIDANCE KEEP REMAIN ON STEADY W 
COURSE.  IF SO...WARM SEA SURFACE TEMPERATURES WOULD SUSTAIN 
EXPECTED INTENSIFICATION.
 
TROPICAL DEPRESSION MARIE AT 18.7N 123.4W AT 06/1500 UTC OR 920 
NM W-SW OF SRN TIP OF BAJA CALIFORNIA MOVING W OR 270 DEG AT 2 
KT.  ESTIMATED MINIMUM CENTRAL PRES 1006 MB.  MAXIMUM SUSTAINED 
WIND SPEED 30 WITH GUSTS TO 40 KT.  REFER TO LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC 
AND INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCPEP4/WTPZ34 KNHC FOR MORE DETAILS.  MARIE IS TAKING HER 
LAST BREATHS AS TROPICAL CYCLONE AS IT HAS DRIFTED INTO COOL SEA 
SURFACE TEMPERATURES WITH A DRIER AND STABLE AIR MASS.  ITS 
DEMISE IS NOW MEASURED IN HOURS SINCE MOST DEEP CONVECTION IS 
ALL BUT GONE AT PRESENT.   MARIE SHOULD BECOME A REMNANT LOW 
PRES WITHIN 12 HRS.

AREA OF LOW PRES 1007 MB AT 12N89W...WITH LITTLE MOVEMENT 
DETECTED.  SYSTEM APPEARS TO BE LOSING ITS BATTLE AGAINST AN 
INCREASED NE WIND SHEAR ALOFT...BUT COULD ONLY BE A TEMPORARY 
SETBACK AS UPPER ENVIRONMENT IMPROVES FURTHER W.  SINCE SYSTEM 
DOES NOT APPEAR TO MOVE...IT REMAINS UNDER ADVERSE CONDITIONS 
ALOFT AND THEREFORE LOSING ITS CYCLONIC ORGANIZATION.  CENTER 
HAS LOST ITS SURROUNDING DEEP CONVECTION AND CLOUD TOPS HAVE 
WARMED AS THEY DRIFT AWAY FROM CENTER.  UNLESS SYSTEM MOVES W 
INTO MORE FAVORABLE CONDITIONS IT COULD WEAKEN BEYOND REPAIR. 
NEW CYCLONE FORMATION IN BAY OF CAMPECHE...JUST N OF GULF OF 
TEHUANTEPEC...PRESENTS NEW CHALLENGE TO FORECAST INFLUENCE OF 
ONE SYSTEM UNTO THE OTHER.

...ITCZ...
ITCZ AXIS ALONG 12N87W TO 11N95W TO 14N104W TO 07N109W TO 
12N128W TO 09N140W. NO ORGANIZED CONVECTION NEAR ITCZ.

...DISCUSSION...
EXPANDING UPPER LEVEL RIDGE FROM SW N ATLC TO ANTICYCLONE OVER 
YUCATAN PENINSULA TO SECOND ANTICYCLONE GYRE AT 17N125W ABOUT 
TO BE DISRUPTED BY SW DIGGING UPPER LEVEL TROUGH EXTENDING FROM 
NRN TEXAS TO TIP OF BAJA CALIFORNIA TO 14N113W.  THIS TROUGH IS 
CONTRIBUTING TO DIFFLUENT FLOW ALOFT ENHANCING INTENSIFICATION 
OF NORBERT AND TO LESSER EXTENT NEW TROPICAL DEPRESSION IN BAY 
OF CAMPECHE.   

ELSEWHERE AT THE SURFACE...
GULF OF TEHUANTEPEC WIND EVENT APPEARS TO HAVE COME TO A CLOSE 
...BUT NEW TROPICAL DEPRESSION FORMATION IN ERN BAY OF CAMPECHE 
COULD AGAIN FORCE N WINDS ACROSS ISTHMUS OF TEHUANTEPEC AND 
INCREASE WINDS TO 25-30 KT.  WITH LOW PRES AT 12N89W DRIFTING 
INTO PICTURE JUST S OF TEHUANTEPEC...SOLUTION BECOMES MUCH MORE 
COMPLICATED AND MODEL GUIDANCE HIGHLY UNRELIABLE.  WHILE N WINDS 
20-30 KT FOR SHORT PERIOD OF TIME ARE FORECAST...CONFIDENCE IS 
VERY LOW. 

HIGH PRES 1024 MB ALONG 30N PUSHING LONG PERIOD SWELL TRAIN INTO 
E PAC SPREADING INTO NW HALF OF AREA...BUT SUBSIDING AT PRESENT 
TIME.  SHIP REPORTS INDICATE SEAS TO 9 FT WHILE MODEL GUIDANCE 
LOWER HEIGHTS SLIGHTLY MORE AND FASTER.

LONG PERIOD SW SWELL OVER SW HALF OF BASIN CONTINUES.  OUTSIDE 
OF INFLUENCE OF ACTIVE TROPICAL CYCLONES.  NWW3 SOLUTION TENDS 
FOR SMALLER AREA COVERAGE AND LOWER SEA HEIGHT THAN FORECAST. 

$$
WALLY BARNES