Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 080602
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST SUN NOV 08 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...SPECIAL FEATURES...

TROPICAL STORM IDA WAS UPGRADED TO HURRICANE AS OF 08/0415 UTC. 
HURRICANE IDA IS CENTERED NEAR 20.1N 85.3W AT 08/0600 UTC OR 
ABOUT 96 NM ESE OF COZUMEL MEXICO AND ABOUT 105 NM S OF THE 
WESTERN TIP OF CUBA MOVING NNW AT 10 KT. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 980 MB. MAXIMUM SUSTAINED WIND SPEED IS 75 
KT WITH GUSTS TO 90 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. 
NUMEROUS STRONG CONVECTION IS WITHIN A 60 NM RADIUS OF 20N85W 
WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE REMAINDER 
OF THE AREA FROM 18N-23N BETWEEN 80W-87W INCLUDING PORTIONS OF 
CUBA/YUCATAN PENINSULA AND ALL OF THE CAYMAN ISLANDS. 

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 45W/46W S OF 17N MOVING W NEAR 15 KT. THE 
WAVE WAS RELOCATED BASED ON SATELLITE IMAGERY AND SATELLITE 
DERIVED WINDS. WAVE REMAINS WITHIN A BROAD AREA OF MAXIMUM TOTAL 
PRECIPITABLE WATER VALUES BETWEEN 32W-50W. CLUSTERS OF SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION COVER THE AREA FROM 
10N-18N BETWEEN 33W-46W AND IS BEING ENHANCED BY DIFFLUENCE 
ALOFT ON THE W SIDE OF AN UPPER RIDGE.

TROPICAL WAVE IS ALONG 64W S OF 19N MOVING W 10-15 KT. WAVE 
CONTINUES MOVING BENEATH DRY UPPER LEVEL NLY FLOW THAT COVERS 
THE E CARIBBEAN AND THUS NO SIGNIFICANT DEEP CONVECTION. 

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N12W 6N26W 7N44W 7N54W 9N62W. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 
INLAND AND WITHIN 90/120 NM ALONG THE COAST OF W AFRICA FROM 
LIBERIA TO SIERRA LEONE AND FROM 2N-10N BETWEEN 28W-43W. 

...DISCUSSION...

GULF OF MEXICO...
THE SURFACE RIDGE THAT HAS COVERED THE GULF IS BEGINNING TO 
SHIFT EASTWARD WITH THE APPROACH OF IDA. THE SURFACE RIDGE AXIS 
EXTENDS FROM A SERIES OF SURFACE HIGHS WITH THE MAIN 1027 MB 
HIGH OFF THE NORTH CAROLINA COAST THROUGH A 1025 MB HIGH ALONG 
THE COAST OF SOUTH CAROLINA TO CENTRAL TEXAS COVERING THE N GULF 
N OF 26N. THE PRESSURE GRADIENT BETWEEN THIS SURFACE RIDGE AND 
HURRICANE IDA IS PRODUCING GALE FORCE WINDS OVER THE SE GULF 
INCLUDING THE STRAITS OF FLORIDA...SEE MIAHSFAT2. A SURFACE 
TROUGH IS OVER THE SW GULF EXTENDING FROM THE W COAST OF THE 
YUCATAN PENINSULA NEAR 19N91W THROUGH A 1010 MB LOW NEAR 21N95W 
TO 24N96W. THIS SURFACE TROUGH/LOW ARE SUPPORTED ALOFT BY UPPER 
LEVEL TROUGH WITH THE AXIS EXTENDING FROM 24N96W TO OVER S 
MEXICO NEAR 18N92W. THE REMAINDER OF THE GULF IS DOMINATED BY AN 
UPPER RIDGE ANCHORED IN THE CENTRAL CARIBBEAN. THE SURFACE 
TROUGH/LOW COUPLED WITH DIFFLUENCE ALOFT ARE GENERATING A BROAD 
AREA OF SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S 
OF 28N W OF 90W TO THE COAST OF MEXICO. CONVECTIVE DEBRIS 
CLOUDS ARE BEING ADVECTED NE AROUND THE PERIPHERY OF AN UPPER 
LEVEL RIDGE AND IS ALSO BRINGING MOISTURE FROM HURRICANE IDA 
NORTHWARD THROUGH THE YUCATAN CHANNEL AND ACROSS CUBA OVER THE 
SE GULF WITH SCATTERED SHOWERS S OF 25N E OF 90W THROUGH THE 
STRAITS OF FLORIDA. 

CARIBBEAN SEA...
THE NW CARIBBEAN SEA IS UNDER THE INFLUENCE OF HURRICANE IDA 
AGAIN TONIGHT. THE CONVECTION ASSOCIATED WITH IDA IS MOVING N-NE 
THROUGH THE YUCATAN CHANNEL AND ACROSS W CUBA INTO THE SE GULF 
OF MEXICO ON THE NORTHERN PERIPHERY OF UPPER LEVEL HIGH ANCHORED 
IN THE CENTRAL CARIBBEAN NEAR 15N76W. DIFFLUENCE ALOFT OVER THE 
SW CARIBBEAN IS GENERATING SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS S OF 13N TO INLAND OVER COLOMBIA BETWEEN 73W-76W. 
E OF THE UPPER LEVEL HIGH IS RELATIVELY DRY AND STABLE AIR WITH 
NLY UPPER LEVEL FLOW DOMINATING THE E CARIBBEAN E OF 72W WITH 
ONLY ISOLATED LOW LEVEL FAST MOVING SHOWERS BEING USHERED IN ON 
MODERATE/STRONG ELY TRADEWINDS.

ATLANTIC OCEAN...
A SURFACE RIDGE CONTROLS THE W ATLC N OF 25N W OF 60W ANCHORED 
BY A SERIES OF SURFACE HIGHS WITH A RIDGE AXIS EXTENDING SE FROM 
THE MAIN 1027 MB HIGH OFF THE NORTH CAROLINA ACROSS BERMUDA TO 
30N60W. FARTHER E IS A COLD FRONT THAT ENTERS THE REGION NEAR 
32N48W AND EXTENDS SW TO 27N55W THEN BECOMING STATIONARY TO 
25N61W WITH A SHEAR AXIS EXTENDING W TO JUST E OF THE CENTRAL 
BAHAMAS NEAR 23N72W. SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS ARE WITHIN 200 NM EITHER SIDE OF THE BOUNDARY E OF 
64W AND ISOLATED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE 
REMAINDER OF THE SHEAR AXIS. SCATTERED SHOWERS AND POSSIBLE 
ISOLATED THUNDERSTORMS ARE FROM OVER THE BAHAMAS ACROSS CUBA AND 
THROUGH THE STRAITS OF FLORIDA COMPLIMENTS OF HURRICANE IDA. THE 
E ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED ON A 
1033 MB HIGH CENTERED NE OF THE AZORES. AN UPPER LEVEL TROUGH IS 
OVER THE E/CENTRAL ATLC EXTENDING AN AXIS THROUGH 32N35W INTO 
THE TROPICS NEAR 14N52W. AN E/W UPPER RIDGE EXTENDS FROM AFRICA 
ALONG 14N TO 44W. DIFFLUENCE ALOFT TO THE E OF THE TROUGH AXIS 
ABOVE AND ALONG THE W EXTENT OF THE ABOVE RIDGE IS ENHANCING THE 
ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE ALONG 45W/46W.  

$$
WALLACE