[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 021154
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI OCT 02 2015

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
1045 UTC.

...SPECIAL FEATURES...

MAJOR HURRICANE JOAQUIN IS CENTERED NEAR 23.4N 74.8W AT 02/1200
UTC OR ABOUT 25 NM NNE OF CLARENCE LONG ISLAND BAHAMAS AND ABOUT
40 NM SSW OF SAN SALVADOR BAHAMAS MOVING NW AT 3 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 937 MB. MAXIMUM SUSTAINED WIND SPEED
IS 115 KT WITH GUSTS TO 140 KT. NUMEROUS MODERATE TO ISOLATED
STRONG CONVECTION IS FROM 20N-25N BETWEEN 70W-78W. SCATTERED
MODERATE CONVECTION AND TSTMS ARE OVER THE NORTHERN-CENTRAL
CARIBBEAN FROM 17N-21N BETWEEN 70W-83W. SEE LATEST INTERMEDIATE
PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC
AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.

A 1003 MB LOW IS CENTERED NEAR 26N53W. THIS CURRENT AREA OF LOW
PRESSURE CONTINUES TO SHOW SIGNS OF ORGANIZATION. ENVIRONMENTAL
CONDITIONS ARE FORECAST TO BE CONDUCIVE FOR THE LOW TO OBTAIN
SUBTROPICAL OR TROPICAL CHARACTERISTICS AND A TROPICAL CYCLONE
IS LIKELY TO FORM WITHIN A COUPLE OF DAYS WHILE THE LOW MOVES
NORTHWARD. GALE FORCE WINDS PREVAIL N OF OF THE LOW BETWEEN 50W
AND 60W WITH ASSOCIATED SEAS OF 9 TO 13 FT. THESE CONDITIONS ARE
FORECAST TO CONTINUE DURING THE NEXT 48 HOURS. THERE IS A HIGH
CHANCE THIS SYSTEM WILL DEVELOP INTO A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS. SCATTERED MODERATE CONVECTION AND TSTMS ARE
OCCURRING FROM 19N TO 29N BETWEEN 47W AND 66W.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE E ATLC WEST OF THE CAPE VERDE
ISLANDS WITH AXIS EXTENDING FROM 18N29W TO A 1009 MB LOW NEAR
11N27W...MOVING W AT 5-10 KT. CIRA LAYER PRECIPITABLE WATER
IMAGERY SHOW THE WAVE IS EMBEDDED IN A MODERATE MOIST
ENVIRONMENT FROM THE SURFACE TO NEARLY 700 MB THAT ALONG WITH
MIDDLE TO UPPER LEVEL DIFFLUENCE IN THE WAVE REGION SUPPORT
SCATTERED MODERATE CONVECTION AND TSTMS FROM 13N TO 18N BETWEEN
25W AND 30W.

FORMER TROPICAL WAVE OVER THE CENTRAL ATLC IS NOW BEING ANALYZED AS
A SURFACE TROUGH. A SCATTEROMETER PASS SHOWED A LOW PRESSURE
CENTER ASSOCIATED WITH IT NEAR 14N39W THAT IS EXPECTED TO
DISSIPATE WITHIN THE NEXT 24 HOURS. EVEN THOUGH CIRA LAYER
PRECIPITABLE WATER IMAGERY SHOW THE TROUGH IS EMBEDDED IN A
MODERATE MOIST ENVIRONMENT FROM THE SURFACE TO 850 MB...SOME DRY
AIR INTRUSION AND STRONG DEEP LAYER WIND SHEAR IN THE
REGION CONTINUE TO HINDER CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N16W TO
A 1009 MB LOW NEAR 11N27W TO 09N39W. A CLUSTER OF MODERATE
CONVECTION AND TSTMS IS FROM 07N TO 14N E OF 19W. THE OTHER AREA
OF CONVECTION IS ASSOCIATED WITH THE EASTERNMOST TROPICAL WAVE. SEE
TROPICAL WAVES SECTION.

...DISCUSSION...

GULF OF MEXICO...

A SHARP MIDDLE- TO UPPER-LEVEL TROUGH EXTENDS FROM ILLINOIS TO
ALABAMA S-SW TO A BASE OVER THE EASTERN BAY OF CAMPECHE. THIS
UPPER TROUGH SUPPORTS A FRONTAL SYSTEM ANALYZED AS A COLD FRONT
FROM 25N81W TO 22N87W TO 19N93W. EXCEPT FOR THE SSE GULF AND THE
YUCATAN CHANNEL...THE CIRA LAYER PRECIPITABLE WATER IMAGERY SHOW
LOW LEVEL DRY AIR ACROSS THE BASIN THAT ALONG WITH STRONG DEEP
LAYER ENVIRONMENTAL WIND SHEAR HINDER CONVECTION.
OTHERWISE...ISOLATED SHOWERS ARE POSSIBLE WITHIN 100 NM S OF THE
COLD FRONT W OF 84W. LOOKING AHEAD...EXPECT FOR THE COLD FRONT
TO START DISSIPATING OVER THE SE GULF TONIGHT. FRESH TO STRONG
NORTHERLY FLOW ASSOCIATED WITH THE FRONT WILL CONTINUE THROUGH
LATE FRIDAY NIGHT. NORTHWESTERLY FLOW OF 15 TO 20 KT ASSOCIATED
WITH THE LARGE AREA OF LOW PRESSURE FROM HURRICANE JOAQUIN IN
THE SW N ATLC WILL DOMINATE THE EASTERN BASIN SATURDAY AND
SUNDAY.

CARIBBEAN SEA...

THE OUTER RAINBANDS OF MAJOR HURRICANE JOAQUIN OVER THE CENTRAL
BAHAMAS CONTINUE TO AFFECT THE NORTH-CENTRAL CARIBBEAN. HEAVY
RAIN AND COASTAL FLOODING HAS BEEN REPORTED ACROSS NE CUBA AND
HISPANIOLA AND MARINE WARNINGS CONTINUE IN EFFECT ACROSS THE
ATLANTIC COAST OF BOTH ISLANDS. TSTMS ACTIVITY IS OBSERVED OVER
SOUTHERN HAITI...THE WINDWARD PASSAGE AND CARIBBEAN WATERS
BETWEEN JAMAICA AND EASTERN CUBA. SCATTERED SHOWERS AND TSTMS
ARE ALSO NOTED W OF JAMAICA FROM 17N TO 21N E OF 83W. JOAQUIN
ALSO HAS DISRUPTED THE TRADE WIND FLOW ACROSS THE
BASIN...SHOWING TO BE VARIABLE AND LESS THAN 15 KT S OF 17N W OF
70W. NORTHWESTERLY WIND FLOW OF 15 KT IS NOTED ALONG CUBA
SOUTHERN OFFSHORE WATERS WHILE WEST-SOUTHWEST WIND FLOW OF 20-25
KT IS BETWEEN JAMAICA AND EASTERN CUBA AND THE WINDWARD PASSAGE.
A SURFACE TROUGH IS OFF THE EASTERN COAST OF THE YUCATAN
PENINSULA AND BELIZE ENHANCING SHOWERS AND TSTMS S OF 20N W OF
85W. IN THE SW BASIN...THE MONSOON TROUGH ENHANCES ISOLATED
SHOWERS AND TSTMS BETWEEN 74W AND 81W. SHALLOW MOISTURE OVER THE
S AND E CARIBBEAN ALONG WITH A TROUGH IN THE UPPER LEVELS
SUPPORT SCATTERED SHOWERS AND TSTMS OVER THE WINDWARD ISLANDS
AND S OF 14N E OF 71W. LOOKING AHEAD...AREAS OF CONVECTIVE
PRECIPITATION ARE EXPECTED TO CONTINUE IMPACTING CUBA AND
PORTIONS OF HISPANIOLA THROUGH LATE SATURDAY AS JOAQUIN TRACKS
NORTHWARD.

...HISPANIOLA...

CURRENTLY...THE OUTER RAINBANDS OF MAJOR HURRICANE JOAQUIN
EXTEND ACROSS THE ISLAND SUPPORTING PERIODS OF HEAVY RAINFALL
PARTICULARLY ACROSS THE WESTERN HALF OF THE ISLAND. A MARINE
WARNING IS IN EFFECT FOR THE ATLANTIC COAST OF HISPANIOLA AS
HURRICANE JOAQUIN REMAINS JUST N OF THE ISLAND. THE CONVECTION
IS EXPECTED TO PERSIST DURING THE NEXT 24 HOURS AS THE HURRICANE
MOVES NORTHWARD.

ATLANTIC OCEAN...

THE MAIN FEATURE ACROSS THE ATLANTIC IS MAJOR HURRICANE JOAQUIN
OVER THE CENTRAL BAHAMAS. PLEASE REFER TO THE SPECIAL FEATURES
SECTION ABOVE FOR MORE DETAILS. THE SECOND AREA OF INTEREST IS A
1003 MB LOW CENTERED NEAR 26N53W. THIS CURRENT NON-TROPICAL AREA
OF LOW PRESSURE CONTINUES TO SHOW SIGNS OF ORGANIZATION AND
THERE IS A HIGH CHANCE IT WILL DEVELOP INTO A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS. GALE FORCE WINDS ARE N OF THE LOW
CENTER BETWEEN 50W AND 60W WITH ASSOCIATED SEAS OF 9 TO 13 FT.
SEE SPECIAL FEATURES SECTION ABOVE FOR FURTHER INFORMATION. NW
OF JOAQUIN...A MIDDLE TO UPPER LEVEL TROUGH SUPPORT A FRONTAL
SYSTEM ANALYZED AS A STATIONARY FRONT FROM 30N79W TO A 1001 MB
LOW NEAR 27N79W WHERE THE FRONT TRANSITIONS TO A COLD FRONT
ACROSS FLORIDA AND INTO SOUTHERN GULF OF MEXICO WATERS.
SCATTERED MODERATE CONVECTION IS N OF 29N W OF 78W. A STATIONARY
FRONT EXTENDS FROM 30N26W TO 27N42W WITH SCATTERED SHOWERS
WITHIN 200 NM EITHER SIDE OF THE BOUNDARY. A SURFACE RIDGE
PREVAILS ACROSS THE NE ATLANTIC.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR
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