000 AXNT20 KNHC 011204 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU NOV 01 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1130 UTC. ...SPECIAL FEATURE... THE CENTER OF TROPICAL STORM NOEL WAS CENTERED NEAR 23.8N 78.5W AT 01/1200 UTC OR ABOUT 95 NM SOUTHWEST OF NASSAU AND ABOUT 150 NM SOUTHEAST OF MIAMI FLORIDA MOVING TOWARD THE NORTH NEAR 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE THE NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND/OR THE PUBLIC ADVISORY UNDER MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. NUMEROUS MODERATE TO SCATTERED STRONG CONVECTION IS PRIMARILY LOCATED TO THE NE OF THE LOW-LEVEL CENTER FROM 22N-26N BETWEEN 73W-79W. THE COLDEST CLOUD TOPS ARE NEAR -85-90C...BUT GENERALLY COVER A SMALLER AREA THAN BEFORE. THE OUTER RAIN BANDS SPREAD FARTHER OUT FROM THE CIRCULATION ROUGHLY S OF 28N W OF ABOUT 70W. NOEL APPEARS TO STILL HAVE A SMALL WINDOW...12 HOURS OR SO...TO STRENGTHEN SLIGHTLY BEFORE INTERACTING WITH A SHORTWAVE TROUGH AND FRONTAL ZONE WHICH WILL FORCE THE STORM TOWARD THE NORTHEAST AND BEGIN EXTRATROPICAL TRANSITION. ...TROPICAL WAVES... TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 74W S OF 18N MOVING W 5-10 KT OVER THE PAST 24 HOURS. IT IS DIFFICULT TO TELL EXACTLY WHERE THIS WAVE IS LOCATED AS MUCH OF THE ASSOCIATED ENERGY HAS BECOME EMBEDDED WITHIN THE CLOUDINESS ASSOCIATED WITH THE TRAILING TROUGH OF NOEL. THE MIMIC TPW ANIMATION SHOWS A WWD MOVING SURGE OF DRY AIR WORKING ITS WAY ACROSS THE CARIB. WHILE SOME OF THIS DRYING IS LIKELY ASSOCIATED WITH CONFLUENCE ALOFT ON THE W SIDE OF AN UPPER LOW...IT DOES APPEAR THAT THIS WAVE IS PLAYING A PART. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 7N27W 6N40W 4N52W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM N AND 180 NM S OF THE AXIS BETWEEN 19W-27W. SIMILAR ACTIVITY IS FURTHER N FROM 10N-13N BETWEEN 33W-38W...POSSIBLY ASSOCIATED WITH A TROPICAL WAVE OR LOW-LEVEL TROUGH. ISOLATED MODERATE IS WITHIN 180 NM N OF THE AXIS BETWEEN 40W-46W. DISCUSSION... GULF OF MEXICO... TIGHT PRES GRADIENT BETWEEN TROPICAL STORM NOEL AND STRONG HIGH PRES NE OF BERMUDA IS KEEPING N TO NE WINDS QUITE STRONG ACROSS THE E GULF AS NOTED IN BUOY DATA AND RECENT SCATTEROMETER PASSES. WINDS RELAX IN THE CENTRAL AND W GULF AS THE GRADIENT SLACKENS WITH THE EXCEPTION OF THE SW CORNER WHERE THE FLOW BACKS TO THE N AND ACCELERATES. MOSAIC DOPPLER RADAR SHOWS THE OUTER BANDS OF NOEL PUSHING ACROSS S AND CENTRAL FLORIDA AND THE STRAITS. WINDS TEND TO INCREASE IN THESE SHOWERS AS IT MIXES DOWN HIGHER MOMENTUM AIR. MOST OF THIS ACTIVITY APPEARS TO BE THINNING OUT AS IT TRAVERSES INTO THE GULF. THE FLOW ALOFT IS FAIRLY ZONAL TO THE N OF A FLAT UPPER RIDGE CENTERED OVER THE CARIBBEAN. A WEAK SHORTWAVE ACROSS THE FL PANHANDLE AND INTO THE CENTRAL GULF IS VEERING THE FLOW MORE TOWARD THE SW IN THE E GULF. THIS SHORTWAVE AND A STRONGER ONE TO FOLLOW WILL BE THE STEERING ELEMENTS TO CAUSE NOEL TO TURN AND ACCELERATE TOWARD THE NE. WATER VAPOR IMAGERY REVEALS WIDESPREAD DRY AIR ACROSS THE REGION WHICH IS HELPING TO SUPPRESS SIGNIFICANT SHOWER ACTIVITY...ESPECIALLY W OF 85W. CARIBBEAN SEA... IR IMAGERY AND DOPPLER RADAR DATA FROM CUBA REVEAL HEAVY RAINS OVER THE ERN PORTION OF THE COUNTRY. ADDITIONAL RAINFALL ACCUMULATIONS OF 2 TO 4 INCHES ARE EXPECTED THERE. THESE RAINS ARE EXPECTED TO CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. SEE THE SPECIAL FEATURE SECTION FOR MORE DETAILS. THE COMBINATION OF A TRAILING TROUGH HANGING SWD FROM TROPICAL STORM NOEL...ALONG 21N80W 10N78W...AND A TROPICAL WAVE PUSHING INTO THE REGION IS GENERATING SCATTERED SHOWERS AND TSTMS GENERALLY BETWEEN 73W AND 82W. THE STRONGEST SMALL CLUSTERS ARE CURRENTLY LOCATED BETWEEN JAMAICA AND THE SW TIP OF HAITI. THE AIR DRIES OUT SOME TO THE W OF TROUGH DRIVEN BY FRESH TO STRONG NWLY WINDS...HOWEVER...A SMALL CLUSTER OF TSTMS HAVE DEVELOPED NEAR THE HONDURAS COAST WITHIN 30 NM OF 16.5N 85.5W WHERE THE LOW-LEVEL FLOW CONVERGES. THE E CARIB IS FAIRLY TRANQUIL UNDER MODERATE TRADE WIND FLOW AND DRIER AIR ADVECTED INTO THE REGION BY NLY WINDS BETWEEN AN UPPER LOW E OF THE AREA AND AN UPPER HIGH CENTERED BETWEEN HISPANIOLA AND COLOMBIA. ATLANTIC OCEAN... THE MAIN STORY IS TROPICAL STORM NOEL WHICH IS MOVING SLOWLY NWD ABOUT 100 NM SW OF NASSAU BAHAMAS. NOEL IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES...WITH POSSIBLE MAXIMUM AMOUNTS OF 15 INCHES...OVER THE BAHAMAS. FOR STORM SPECIFICS SEE THE SPECIAL FEATURE SECTION ABOVE. IN ADDITION TO THE WIND FIELD DIRECTLY ASSOCIATED WITH NOEL...THE TIGHT PRES PATTERN SET UP BETWEEN THE TROPICAL STORM AND STRONG HIGH PRES NE OF BERMUDA IS PRODUCING GALE FORCE WINDS ELSEWHERE IN THE W ATLC W OF 70W. THESE CONTINUOUS WINDS HAVE PRODUCED HAZARDOUS MARINE CONDITIONS ACROSS THIS AREA...WITH SEAS AS HIGH AS 18 FT. DEBRIS MOISTURE FROM NOEL'S CONVECTIVE MASS STRETCHES FAR TO THE E ROUGHLY N OF 24N W OF ABOUT 35W DRIVEN BY STRONG FLOW ASSOCIATED WITH AN UPPER TROUGH. THIS TROUGH IS PROVIDING SOME SUPPORT FOR A NEARLY STALLED BOUNDARY WHICH ENTERS THE AREA NEAR 32N39W AND EXTENDS MAINLY W ALONG 27N50W 26N60W THEN DISSIPATING TOWARD THE E CENTRAL FL COAST. THE FRONT IS HELPING TO TIGHTEN THE GRADIENT SLIGHTLY TO ITS N BUT OTHERWISE HAS LITTLE SUBSTANTIAL IMPACTS. A CUT-OFF UPPER LOW IN THE TROPICAL ATLC NEAR 12N52W IS PRODUCING A SMALL AREA OF CLOUDINESS AND ISOLATED SHOWERS FROM 11N-14N BETWEEN 50W-53W. AN UPPER SW TO WLY JET EXISTS TO THE E OF THIS UPPER LOW ALONG 12N43W 18N36W 18N16W. DIFFLUENCE ALOFT TO THE E OF THE JET COMBINED WITH A POSSIBLE TROPICAL WAVE OR LOW-LEVEL TROUGH IS PRODUCING SCATTERED SHOWERS AND TSTMS FROM 10N-13N BETWEEN 33W-38W. THE REMAINDER OF THE E ATLC IS FAIRLY QUIET UNDER MODERATE SFC RIDGING AND A HIGHLY ELONGATED RIDGE/TROUGH PATTERN. $$ CANGIALOSI