000 AXNT20 KNHC 111127 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SAT NOV 11 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...TROPICAL WAVES... TROPICAL WAVE HAS BEEN RELOCATED TO THE E ALONG 55W S OF 14N MOVING W NEAR 15 KT. THE AXIS WAS ADJUSTED BASED ON A WEAK INVERTED V-SIGNATURE SEEN IN THE LOW-LEVEL CLOUDS. THIS WAVE HAS SIGNIFICANTLY WEAKENED OVER THE LAST DAY OR TWO AS MODERATE TO STRONG SW-WLY WINDS IN COMBINATION WITH STRONG SUBSIDENCE HAS TAKEN ITS TOLL ON THIS ONCE ACTIVE TROPICAL WAVE. NO DEEP CONVECTION OR ORGANIZED CLOUDINESS IS ASSOCIATED WITH THIS FEATURE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N12W 6N34W 8N50W 10N57W 9N63W. THE ITCZ AXIS APPEARS UNUSUALLY QUIET WITH ONLY ISOLATED SHOWERS AND TSTMS WITHIN 240 NM N OF THE AXIS BETWEEN 26W-49W. ...DISCUSSION... GULF OF MEXICO... SOUTHWESTERLY UPPER LEVEL FLOW HAS BECOME MORE UNIFORM ACROSS THE GULF AS THE UPPER RIDGE HAS SHIFTED E...NOW CENTERED ABOVE THE BAHAMAS AND THE ERN SEABOARD...AND A SHORTWAVE TROUGH CONTINUES TO DIG IN THE NW GULF. THE ASSOCIATED SFC FRONT HAS NOW MOVED OFF THE GULF COAST AND AS OF 09Z EXTENDS FROM CENTRAL LOUISIANA TO EXTREME SRN TEXAS. THIS FRONT IS ACCOMPANIED BY A NARROW LINE OF SCATTERED SHOWERS AND TSTMS. BUOYS IN THE NW GULF HAVE MADE SHARP WIND SHIFTS FROM LIGHT SLY TO NLY AND HAVE INCREASED TO 20-25 KT OVER THE PAST FEW HOURS AS STRONG HIGH PRES BUILDS SWD OVER THE CNTRL U.S. THE BROAD SWLY UPPER LEVEL FLOW IS ADVECTING DEBRIS MOISTURE FROM A FEW TROPICAL LOWS IN THE EPAC...ONE OF WHICH IS THE NEWLY FORMED T.D. 20-E...ACROSS S/CNTRL MEXICO AND THE GULF MAINLY S OF 27N. THIS MOISTURE IS NOT A BIG WEATHER FACTOR AS IT IS MAINLY UPPER LEVEL WITH THE 88-D'S ONLY SHOWING A FEW SHOWERS OFF THE COAST OF SW FLORIDA AND SOME ENHANCED SHOWER ACTIVITY S OF THE COLD FRONT IN NRN MEXICO. THE SFC HIGH HAS ALSO SHIFTED NE OF THE AREA BUT CONTINUES TO KEEP LIGHT SE/S WINDS ACROSS THE E AND MID GULF. THIS FLOW TURNS SWLY IN THE N CNTRL GULF JUST AHEAD OF THE APPROACHING FRONT. THE FRONT WILL CONTINUE TO MOVE SE THRU THE DAY TODAY BEFORE SLOWLY BECOMING DIFFUSE AND STATIONARY ON SUN. NLY WINDS WILL INCREASE BEHIND THE WEAK/MODERATE FRONT...BUT ARE FORECAST TO STAY WELL BELOW GALE CRITERIA. CARIBBEAN... THE CARIB REMAINS QUIET THIS MORNING WITH PLENTY OF DRY/STABLE SINKING AIR ALOFT IN PLACE. THE MID-UPPER LEVEL PATTERN PRODUCING THIS STABLE ENVIRONMENT CONSISTS OF AN UPPER RIDGE CENTERED IN THE NW CARIB NEAR 18N84W AND ANOTHER STRONG UPPER HIGH LOCATED E OF THE AREA. A WEAKNESS LIES ABOVE THE CNTRL CARIB INDUCED BY AN UPPER TROUGH TO THE N/NE. THE WEAK LOW PRES SYSTEM THAT HAS BEEN N OF PANAMA FOR THE PAST 36-48 HOURS HAS DISSIPATING...HOWEVER THERE ARE STILL SOME LEFT OVER SCATTERED SHOWERS MOVING ACROSS NICARAGUA. BROKEN PATCHES OF UPPER LEVEL MOISTURE IS IMPINGING ON THE SRN WINDWARD ISLANDS ASSOCIATED WITH A TROPICAL JET AND THE REMNANT MOISTURE OF A TROPICAL WAVE. HOWEVER...THE UPPER ATMOSPHERE IS SO DRY THAT MOST OF THIS IS QUICKLY BREAKING UP. LITTLE CHANGE IS EXPECTED THRU THE WEEKEND AS DRY AIR REMAINS ESTABLISHED ACROSS THE AREA. TRADE WINDS ARE MODERATE AND WILL LIKELY REMAIN THAT WAY OVER THE NEXT COUPLE DAYS. ATLANTIC OCEAN... A SHORT WAVELENGTH RIDGE/TROUGH/RIDGE/TROUGH/RIDGE MID-UPPER LEVEL PATTERN IS ESTABLISHED ACROSS THE SUBTROPICAL ATLC. VERY DRY AND STABLE AIR ASSOCIATED WITH THE FIRST OF THESE RIDGES IS OVER THE SW NORTH ATLC...INCLUDING THE BAHAMAS. A NARROW UPPER TROUGH EXTENDING S ALONG 53W HAS AN ASSOCIATED SFC COLD FRONT ALONG 32N53W 23N62W TO NEAR THE N COAST OF THE DOMINICAN REPUBLIC. A PRE-FRONTAL TROUGH LIES ABOUT 120 NM AHEAD OF THE FRONT N OF 24N. ONLY LOW AND MID LEVEL CLOUDS AND ISOLATED SHOWERS ARE ALONG THE FRONT AND TROUGH IN THE DISCUSSION AREA. MORE CONCENTRATED SHOWER ACTIVITY IS ALONG THE BOUNDARY N OF 32N. THE UPPER TROUGH IS SHOWING SINGS OF CUTTING OFF...AS SUGGESTED BY GFS...WHICH WILL LIKELY LEAD TO A WEAKENING OF THE SFC FRONT. A HIGH AMPLITUDE NARROW DEEP-LAYER RIDGE LIES ACROSS THE CNTRL ATLC BETWEEN 40W-50W. E OF THE RIDGE...THE PATTERN IS DOMINATED BY A LARGE CUT OFF UPPER LOW CENTERED NEAR 31N30W. THIS UPPER FEATURE HAS A RELATED SFC LOW WHICH IS ANALYZED AT 1006 MB JUST E OF THE UPPER-LEVEL CENTER. MOST OF THE WEATHER IS E OF THE SFC LOW...WHERE SCATTERED MODERATE CONVECTION EXISTS N OF 28N BETWEEN 23W-26W...LINED ALONG A SFC TROUGH. MODELS SHOW THIS LARGE E OF THIS LARGE LOW...LIES A WEAK RIDGE ALONG 16W. IN THE DEEP TROPICS...THE MAIN FEATURE IS A WELL-DEFINED UPPER LEVEL JET STREAM WHICH ORIGINATES NEAR VENEZUELA AND RACES ENE ALONG 15N56W 16N32W THEN NORTHEASTWARD ALL THE WAY TO THE COAST OF N AFRICA NEAR 21N17W. HIGHLY SHEARED SCATTERED SHOWERS AND TSTMS ARE WITHIN 240 NM S OF THE JET AXIS. UPPER CONFLUENCE W OF THE AXIS IS ENHANCING STRONG SUBSIDENCE. $$ CANGIALOSI