[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 062355
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST FRI NOV 06 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 DEPRESSION IDA IS CENTERED NEAR 15.7N 83.9W AT 06/2100
UTC OR ABOUT 55 NM NW OF CABO GRACIAS A DIOS ON THE NICARAGUA/
HONDURAS BORDER MOVING N AT 7 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH
GUSTS TO 40 KT. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IS
LOCATED N OF THE CENTER OVER THE NW CARIBBEAN FROM 16N-22N
BETWEEN 80W-87W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/
WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 32W S OF 14N MOVING W NEAR 10 KT. THE
WAVE REMAINS WITHIN A BROAD AREA OF MAXIMUM TOTAL PRECIPITABLE
WATER VALUES BETWEEN 28W-41W AND A BROAD AREA OF 850 MB RELATIVE
VORTICITY S OF 13N BETWEEN 25W-35W. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 3N-15N BETWEEN 27W-36W AND IS LARGELY
ENHANCED BY UPPER LEVEL DIFFLUENCE ASSOCIATED E OF UPPER LEVEL
TROUGHING ACROSS THE CENTRAL ATLC.

TROPICAL WAVE IS ALONG 55W S OF 17N MOVING W NEAR 10 KT. THE
WAVE CONTINUES MOVING BENEATH DRY NW UPPER LEVEL FLOW AND THUS
NO SIGNIFICANT DEEP CONVECTION IS NOTED IN THE VICINITY OF THE
WAVE AXIS. HOWEVER...ISOLATED LOW-LEVEL SHOWERS ARE N OF 13N
BETWEEN 52W-57W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 8N13W 9N30W 9N33W 11N53W 11N56W
TO NE VENEZUELA NEAR 10N63W. ISOLATED MODERATE CONVECTION IS
FROM 5N-9N BETWEEN 24W-28W.

...DISCUSSION...

GULF OF MEXICO...
A 1028 MB HIGH IS CENTERED OVER SOUTH CAROLINA NEAR 34N82W WITH
NE SURFACE FLOW OBSERVED ACROSS MUCH OF THE GULF THIS EVENING.
THIS NELY FLOW FILTERS INTO THE SW GULF AND BAY OF CAMPECHE NEAR
A SURFACE TROUGH THAT AT 06/2100 UTC EXTENDS FROM 18N93W TO
22N96W. THIS SURFACE TROUGH IS SUPPORTED ALOFT BY AN UPPER LEVEL
TROUGH WITH AXIS EXTENDING ALONG THE TEXAS GULF COAST SOUTHWARD
ALONG 97W AND INTO THE E PACIFIC REGION. THE SURFACE TROUGH
ALONG WITH MIDDLE TO UPPER LEVEL DIFFLUENCE E OF THE UPPER LEVEL
TROUGH AXIS IS GENERATING SCATTERED SHOWERS S OF 26N W OF 90W.
CONVECTIVE DEBRIS CLOUDINESS IS BEING ADVECTED NE AROUND THE
PERIPHERY OF AN UPPER LEVEL RIDGE THAT REMAINS ANCHORED IN THE
WESTERN CARIBBEAN NEAR 14N74W. THIS UPPER LEVEL ANTICYCLONIC
FLOW IS ALSO BRINGING MOISTURE FROM TROPICAL DEPRESSION IDA
NORTHWARD THROUGH THE YUCATAN CHANNEL AND SE GULF WITH ISOLATED
SHOWERS S OF 25N BETWEEN THE STRAITS OF FLORIDA AND 90W.

CARIBBEAN SEA...
THE WESTERN CARIBBEAN SEA IS UNDER THE INFLUENCE OF TROPICAL
DEPRESSION IDA THIS EVENING. THE CONVECTION ASSOCIATED WITH IDA
IS ADVECTING N-NE ACROSS THE NW CARIBBEAN AND WESTERN CUBA INTO
THE SE GULF OF MEXICO ON THE NW PERIPHERY OF UPPER LEVEL
ANTICYCLONIC FLOW. THIS FLOW IS ANCHORED ON AN UPPER LEVEL HIGH
CENTERED NEAR 14N74W. A SURFACE TROUGH IS ANALYZED ALONG 77W
FROM JAMAICA TO 10N. THIS SURFACE TROUGH IS GENERATING ISOLATED
SHOWERS WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS WITH
PARTIAL ENHANCEMENT OF THIS ACTIVITY DUE TO UPPER LEVEL
DIFFLUENCE FROM THE UPPER LEVEL HIGH. EAST OF THE UPPER HIGH...
RELATIVELY DRY AND STABLE N-NW UPPER LEVEL FLOW DOMINATES OVER
THE EASTERN CARIBBEAN WITH ONLY ISOLATED LOW-LEVEL SHOWERS
USHERED IN ON 10-15 KT TRADEWINDS.

ATLANTIC OCEAN...
A SURFACE RIDGE CONTROLS THE W ATLC W OF 67W ANCHORED ON A 1028
MB HIGH CENTERED OVER SOUTH CAROLINA NEAR 34N82W. A FEW ISOLATED
SHOWERS ARE NOTED ON SATELLITE IMAGERY MOVING ACROSS THE NW
BAHAMAS UNDER BRISK NE SURFACE WINDS. FARTHER EAST...A COLD
FRONT ENTERS THE DISCUSSION AREA NEAR 32N60W AND EXTENDS SW TO
26N67W. ISOLATED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE
COLD FRONT. A PRE-FRONTAL TROUGH APPEARS TO BE EAST OF THE FRONT
WITH SCATTERED SHOWERS N OF 24N BETWEEN 52W-60W. THIS AREA IS
LOCATED WITHIN A WEAKNESS OF THE SUB-TROPICAL RIDGE ACROSS THE
CENTRAL ATLC. THE FRONTAL SYSTEM IS SUPPORTED ALOFT BY AN UPPER
LEVEL TROUGH PROGRESSING ACROSS THE WESTERN NORTH ATLC REMAINING
N OF 26N. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE
INFLUENCE OF A SURFACE RIDGE ANCHORED ON A 1032 MB HIGH CENTERED
OVER THE AZORES. AN UPPER LEVEL TROUGH IS ALOFT OVER THE EASTERN
ATLC AND EXTENDS A TROUGH AXIS FROM 28N42W TO 13N58W 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 32W. THE AREA
COVERS FROM 14N-21N BETWEEN 26W-41W.

$$
HUFFMAN




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