Atlantic Tropical Weather Discussion

000
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