[Tropical] Tropical Weather Discussion

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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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