TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE OCT 23 2012

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…WEATHER OBSERVATIONS…RADAR…AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

…SPECIAL FEATURES…

TROPICAL STORM SANDY IS CENTERED NEAR 13.4N 77.9W AT 23/1200 UTC
OR ABOUT 280 NM SSW OF KINGSTON JAMAICA MOVING NNE AT 3 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED
WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC
INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS.
NUMEROUS STRONG CONVECTION IS WITHIN 45 NM OF LINE FROM 11N78W
TO 13N76W WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE
REMAINDER OF THE AREA FROM 10N-16N BETWEEN 74W-79W AND S OF 15N
BETWEEN 69W-73W. CLUSTERS OF SCATTERED MODERATE/STRONG
CONVECTION ARE S OF 14N W OF 79W TO THE COAST OF PANAMA TO
NICARAGUA. SANDY IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS
OF 5 TO 10 INCHES ACROSS JAMAICA…HAITI…THE DOMINICAN
REPUBLIC…AND EASTERN CUBA…WITH ISOLATED MAXIMUM AMOUNTS OF
16 INCHES POSSIBLE…ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN.
THESE RAINS MAY PRODUCE LIFE THREATENING FLASH FLOODS AND
MUDSLIDES.

TROPICAL DEPRESSION NINETEEN IS CENTERED NEAR 24.1N 51.5W AT
23/0900 OR ABOUT 715 NM NE OF THE LEEWARD ISLANDS MOVING N-NE AT
10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006. MAXIMUM
SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST
NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/ WTNT34
KNHC AND THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS FROM 23N-26N BETWEEN 48W-52W WITH
CLUSTERS OF SIMILAR CONVECTION WITHIN 45/60 NM OF LINE FROM
16N46W 25N47W TO 30N60W.

…TROPICAL WAVES…

TROPICAL WAVE IS ANALYZED ALONG 26W/27W BETWEEN 9N-15N MOVING W
10-15 KT. WAVE IS ALONG THE LEADING EDGE OF A SURGE OF DEEP
MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY.
HOWEVER THERE IS NO ASSOCIATED DEEP CONVECTION.

TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC IS ANALYZED FROM
13N39W TO 9N38W DRIFTING W. WAVE IS EMBEDDED WITHIN A NARROW
SURGE OF MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER
IMAGERY. HOWEVER THERE IS NO ASSOCIATED DEEP CONVECTION.

…ITCZ/MONSOON TROUGH…

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL
ATLC NEAR 12N16W OF THE E TROPICAL WAVE NEAR 8N26W CONTINUING
ALONG 9N32W THEN S OF THE W TROPICAL WAVE TO 8N41W WITH THE ITCZ
BEGINS AND CONTINUES ALONG 9N47W TO 9N53W. SCATTERED MODERATE/
STRONG CONVECTION IS FROM 4N-7N BETWEEN 28W-32W. CLUSTERS OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 90 NM ALONG
THE COAST OF W AFRICA BETWEEN 10N-13N…WITHIN 120 NM OF LINE
FROM 4N12W TO 7N15W…WITHIN 45 NM OF LINE FROM 7N15W TO TO
14N21W…AND FROM 6N-10N BETWEEN 28W-37W.

…DISCUSSION…

GULF OF MEXICO…
A BROAD UPPER RIDGE EXTENDS FROM SW MEXICO OVER TEXAS/LOUISIANA
GIVING THE GULF NW FLOW ALOFT WITH DRY CONTINENTAL AIR
REMAINING IN PLACE OVER THE GULF. A BROAD SURFACE RIDGE
DOMINATES THE GULF THIS MORNING ANCHORED BY A 1024 MB HIGH OVER
NORTH CAROLINA. A SHORTWAVE UPPER TROUGH EXTENDS FROM THE
FLORIDA PENINSULA S ACROSS CUBA INTO THE NW CARIBBEAN GENERATING
CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE
STRAITS OF FLORIDA S OF 24N E OF 81W. ISOLATED SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90 NM ALONG THE COAST OF
MEXICO S OF 24N W OF 95W. THIS IS LEAVING THE REMAINDER OF THE
GULF WITH REMARKABLY CLEAR SKIES AGAIN THIS MORNING. E WINDS
WILL INCREASE ACROSS THE SE GULF TODAY AND CONTINUE THROUGH LATE
WED. THESE WINDS ARE THE RESULT FROM PRESSURE GRADIENT BETWEEN
SURFACE RIDGE OVER THE GULF AND W ATLC AND TROPICAL STORM SANDY
IN THE CARIBBEAN.

CARIBBEAN SEA…
THE PRIMARY CONCERN THIS MORNING IS TROPICAL STORM SANDY IN THE
S/CENTRAL CARIBBEAN…PLEASE SEE SPECIAL FEATURES ABOVE. A
SHORTWAVE UPPER TROUGH EXTENDS FROM THE FLORIDA PENINSULA ACROSS
CUBA OVER THE NW CARIBBEAN NEAR 15N83W GENERATING ISOLATED
SHOWERS/THUNDERSTORMS FROM 15N-21N W OF 78W INCLUDING THE GULF
OF HONDURAS. ABUNDANT MOISTURE REMAINS OVER THE CARIBBEAN
ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE
REMAINDER OF THE CENTRAL CARIBBEAN BETWEEN 69W-78W. TROPICAL
STORM SANDY WILL MOVE N INTENSIFYING TO HURRICANE BEFORE MOVING
ACROSS JAMAICA WED EVENING AND CUBA THU BEFORE BECOMING A
TROPICAL STORM ONCE AGAIN AS IT CONTINUES INTO THE W ATLC THU
AFTERNOON.

ATLANTIC OCEAN…
BROAD UPPER TROUGH COVERS THE W ATLC N OF 28N W OF 52W
SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR
32N54W TO 27N62W WHERE IT DISSIPATES E OF THE BAHAMAS NEAR
25N68W. ISOLATED SHOWERS ARE WITHIN 60 NM E OF THE FRONT. THE
SHORTWAVE UPPER TROUGH THAT EXTENDS FROM THE FLORIDA PENINSULA
INTO THE NW CARIBBEAN COUPLED WITH AN UPPER RIDGE THAT EXTENDS
FROM HISPANIOLA NEAR 19N70W TO 27N68W ARE GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF 26N TO ACROSS THE GREATER
ANTILLES INTO THE CARIBBEAN BETWEEN 67W-80W. A SURFACE RIDGE
REMAINS OVER THE W ATLC N OF 26N W OF 66W INTO THE GULF OF
MEXICO. AN UPPER TROUGH IN THE NE ATLC DIPS S TO 21N E OF 28W
SUPPORTING A DISSIPATING COLD FRONT THAT EXTENDS THROUGH 32N20W
TO 28N29W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM E OF THE
FRONT. A BROAD UPPER RIDGE EXTENDS ACROSS THE TROPICAL ATLC FROM
AFRICA NEAR 11N16W ALONG 17N34W TO 23N38W AND IS DRAWING
TROPICAL MOISTURE N AWAY FROM THE TROPICAL WAVES. SURFACE RIDGE
WILL REMAIN ACROSS THE AREA TODAY THROUGH WED. TROPICAL STORM
SANDY WILL MOVE ACROSS CUBA INTO THE W ATLC ON THU ACROSS
BAHAMAS EARLY FRI THEN NE OF THE BAHAMAS ON SAT NIGHT.