655  
AXNT20 KNHC 072353  
TWDAT  
 
TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST SAT NOV 07 2009  
 
TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL  
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS  
OF SOUTH AMERICA...AND 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH  
2315 UTC.  
   
..SPECIAL FEATURES
 
 
TROPICAL STORM IDA IS CENTERED NEAR 19.5N 84.4W AT 08/0000 UTC  
OR ABOUT 155 NM ESE OF COZUMEL MEXICO AND ABOUT 140 NM SSE OF  
THE WESTERN TIP OF CUBA MOVING NNW AT 9 KT. ESTIMATED MINIMUM  
CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WIND SPEED IS 60  
KT WITH GUSTS TO 75 KT. NUMEROUS MODERATE/SCATTERED STRONG  
CONVECTION IS FROM 18N-21N BETWEEN 82W-87W. SCATTERED  
MODERATE/ISOLATED STRONG CONVECTION IS ELSEWHERE FROM 16N-23N  
BETWEEN 76W-87W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/  
WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.  
   
..TROPICAL WAVES
 
 
TROPICAL WAVE IS ALONG 41W S OF 17N MOVING W NEAR 15 KT. THE  
WAVE REMAINS WITHIN A BROAD AREA OF MAXIMUM TOTAL PRECIPITABLE  
WATER VALUES BETWEEN 32W-45W AND A BROAD AREA OF 850 MB RELATIVE  
VORTICITY N OF 9N BETWEEN 35W-50W. WIDELY SCATTERED MODERATE  
CONVECTION IS FROM 11N-17N BETWEEN 34W-46W AND IS LARGELY  
ENHANCED BY UPPER LEVEL DIFFLUENCE ASSOCIATED E OF UPPER LEVEL  
TROUGHING ACROSS THE CENTRAL ATLC BETWEEN 40W-55W.  
 
TROPICAL WAVE IS ALONG 63W S OF 19N MOVING W NEAR 15 KT. THE  
WAVE CONTINUES MOVING BENEATH DRY NLY UPPER LEVEL FLOW ACROSS  
THE EASTERN CARIBBEAN AND THUS NO SIGNIFICANT DEEP CONVECTION IS  
NOTED IN THE VICINITY OF THE WAVE AXIS. HOWEVER...ISOLATED LOW-  
LEVEL SHOWERS ARE OVER THE LEEWARD ISLANDS STRETCHING WESTWARD  
TO PUERTO RICO.  
   
..ITCZ
 
 
THE ITCZ AXIS IS CENTERED ALONG 9N13W 6N23W 7N39W 7N43W 10N62W.  
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N  
BETWEEN 7W-11W. ISOLATED MODERATE CONVECTION IS FROM 6N-9N  
BETWEEN 52W-56W.  
   
..DISCUSSION
 
 
GULF OF MEXICO...  
A SURFACE RIDGE EXTENDS ACROSS THE SE CONUS AND EASTERN TEXAS  
CONTINUING SOUTHWARD OVER EASTERN MEXICO TO 20N99W. STRONG  
EASTERLY SURFACE FLOW IS OBSERVED ACROSS MUCH OF THE GULF THIS  
EVENING. THIS ELY FLOW FILTERS NORTH OF TROPICAL STORM IDA INTO  
THE SW GULF AND BAY OF CAMPECHE NEAR A SURFACE TROUGH THAT AT  
07/2100 UTC EXTENDS FROM 24N97W INTO A 1009 MB LOW CENTERED NEAR  
21N95W TO 19N92W. THE SURFACE TROUGH AND LOW ARE SUPPORTED ALOFT  
BY UPPER LEVEL TROUGHING WITH AXIS EXTENDING FROM THE TEXAS GULF  
ALONG 95W TO THE BAY OF CAMPECHE AND INTO THE E PACIFIC REGION.  
THE SURFACE FEATURES ALONG WITH MIDDLE TO UPPER LEVEL DIFFLUENCE  
E OF THE UPPER LEVEL TROUGH AXIS IS GENERATING SCATTERED SHOWERS  
S OF 27N W OF 86W. CONVECTIVE DEBRIS CLOUDINESS IS BEING  
ADVECTED NE AROUND THE PERIPHERY OF AN UPPER LEVEL RIDGE THAT  
REMAINS ANCHORED IN THE WESTERN CARIBBEAN NEAR 13N75W. THIS  
UPPER LEVEL ANTICYCLONIC FLOW IS ALSO BRINGING MOISTURE FROM  
TROPICAL STORM IDA NORTHWARD THROUGH THE YUCATAN CHANNEL  
AND SE GULF WITH SCATTERED SHOWERS S OF 25N BETWEEN THE STRAITS  
OF FLORIDA AND 90W...INCLUDING PORTIONS OF THE YUCATAN PENINSULA.  
 
CARIBBEAN SEA...  
THE NW CARIBBEAN SEA IS UNDER THE INFLUENCE OF TROPICAL  
STORM IDA THIS EVENING. THE CONVECTION ASSOCIATED WITH IDA IS  
MOVING N-NE THROUGH THE YUCATAN CHANNEL AND ACROSS MUCH OF CUBA  
INTO THE SE GULF OF MEXICO ON THE NORTHERN PERIPHERY OF UPPER  
LEVEL ANTICYCLONIC FLOW. THIS FLOW IS ANCHORED ON AN UPPER LEVEL  
HIGH CENTERED NEAR 13N75W. A SURFACE TROUGH IS ANALYZED ALONG  
78W FROM 14N TO EASTERN PANAMA. ISOLATED SHOWERS ARE WITHIN 120  
NM EITHER SIDE OF THE SURFACE TROUGH AXIS WITH ENHANCEMENT OF  
THIS ACTIVITY DUE TO UPPER LEVEL DIFFLUENCE FROM THE UPPER LEVEL  
HIGH. EAST OF THE UPPER LEVEL HIGH... RELATIVELY DRY AND STABLE  
NLY UPPER LEVEL FLOW DOMINATES OVER THE EASTERN CARIBBEAN E OF  
72W WITH ONLY ISOLATED LOW-LEVEL SHOWERS NOTED ON SATELLITE  
IMAGERY BEING USHERED IN ON 15-20 KT ELY TRADEWINDS.  
 
ATLANTIC OCEAN...  
A SURFACE RIDGE CONTROLS THE W ATLC N OF 25N W OF 60W ANCHORED  
ON A 1026 MB HIGH CENTERED NEAR 33N76W. A FEW ISOLATED SHOWERS  
ARE NOTED ON SATELLITE IMAGERY MOVING OVER THAT AREA AND ACROSS  
THE NW BAHAMAS UNDER BRISK NE SURFACE WINDS. FARTHER EAST...A  
COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N50W AND EXTENDS SW  
TO 28N55W AND THEN STATIONARY TO 24N62W. A SHEARLINE THEN  
EXTENDS WESTWARD TO THE CENTRAL BAHAMAS NEAR 23N75W. SCATTERED  
SHOWERS AND POSSIBLE ISOLATED TSTMS ARE WITHIN 120 NM EITHER  
SIDE OF THE COLD AND STATIONARY FRONTS WHILE ISOLATED SHOWERS  
ARE WITHIN 90 NM EITHER SIDE OF THE SHEARLINE. THIS FRONTAL ZONE  
IS LOCATED WITHIN A WEAKNESS OF THE SUB-TROPICAL RIDGE ACROSS  
THE CENTRAL ATLC AND IS SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH  
PROGRESSING ACROSS THE WESTERN NORTH ATLC REMAINING N OF 27N.  
THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A  
SURFACE RIDGE ANCHORED ON A 1033 MB HIGH CENTERED NE OF THE  
AZORES NEAR 40N22W. AN UPPER LEVEL TROUGH IS ALOFT OVER THE  
CENTRAL ATLC AND EXTENDS A TROUGH AXIS FROM 26N43W TO 10N56W IN  
THE TROPICAL NORTH ATLC. UPPER LEVEL DIFFLUENCE LOCATED EAST OF  
THE TROUGH AXIS IS GENERATING POSSIBLE ISOLATED SHOWERS NORTH OF  
THE AREA ASSOCIATED WITH THE TROPICAL WAVE ALONG 41W. THE AREA  
COVERS FROM 17N-27N BETWEEN 27W-43W.  
 

 
HUFFMAN  
 
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