[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011150
TWDAT

TROPICAL WEATHER DISCUSSION
NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE OCT 01 2013

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 JERRY IS CENTERED NEAR 27.2N 43.7W AT 01/0900 UTC
OR ABOUT 1140 NM E OF BERMUDA AND ABOUT 1060 NM WSW OF THE
AZORES REMAINING STATIONARY. ESTIMATED MINIMUM CENTRAL PRESSURE
IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO
50 KT. ISOLATED MODERATE CONVECTION IS FROM 23N-30N BETWEEN 39W-
46W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.

A SURFACE TROUGH IS ANALYZED ALONG 82W WITH A 1008 MB LOW
CENTERED ALONG THE AXIS NEAR 16N82W PROVIDING FOCUS FOR LOW-
LEVEL MOISTURE CONVERGENCE AND SCATTERED MODERATE CONVECTION
FROM 13N-20N BETWEEN 76W-83W. A RECENT ASCAT PASS AROUND 01/0222
UTC INDICATED THE TROUGH AXIS WITH THE STRONGEST WINDS NOTED ON
THE PASS FROM 14N-19N BETWEEN 79W-81W...LIKELY EMBEDDED WITHIN
THE AREA OF DEEPER ONGOING CONVECTION. SOME DEVELOPMENT OF THIS
LOW CENTER IS POSSIBLE DURING THE NEXT FEW DAYS WHILE IT MOVES
NORTHWESTWARD AROUND 9 KNOTS. THIS SYSTEM HAS A MEDIUM CHANCE
PERCENT OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
UPPER LEVEL WINDS ARE EXPECTED TO BE MARGINALLY CONDUCIVE FOR
DEVELOPMENT WHEN THE DISTURBANCE MOVES ACROSS THE SOUTHERN GULF
OF MEXICO LATER THIS WEEK. THE SYSTEM HAS A MEDIUM CHANCE OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. LOCALLY
HEAVY RAINS MAY AFFECT PARTS OF JAMAICA...CUBA...AND THE CAYMAN
ISLANDS DURING THE NEXT DAY OR TWO.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 08N27W TO 15N26W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH A MAXIMUM IN TOTAL PRECIPITABLE
WATER IMAGERY THAT REMAINS SOUTH-SOUTHWEST OF THE CAPE VERDE
ISLANDS IN THE VICINITY OF 09N26W. THIS ALONG WITH A BROAD
CYCLONIC CLOUD PRESENTATION S OF 13N IS GENERATING SCATTERED
MODERATE AND ISOLATED STRONG CONVECTION FROM 07N-13N BETWEEN 25W-
31W.

TROPICAL WAVE EXTENDS FROM 11N38W TO 20N39W MOVING W AT 15 KT.
THE WAVE IS EMBEDDED WITHIN A VERY MOIST ENVIRONMENT AS NOTED
TOTAL PRECIPITABLE WATER IMAGERY WHICH REMAINS STRETCHED FROM
07N-22N BETWEEN 34W-42W AND CONTINUES TO COINCIDE WITH SURFACE
TO 700 MB TROUGHING AND A RELATIVE VORTICITY MAXIMUM ALONG THE
WAVE AXIS NEAR 16N. ISOLATED MODERATE CONVECTION IS FROM 11N-19N
BETWEEN 36W-42W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 17N16W TO
16N20W THEN RESUMES NEAR 10N21W TO 08N30W TO 11N36W. THE
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N39W TO
05N52W. OUTSIDE OF CONVECTION ASSOCIATED WITH THE TROPICAL
WAVES...ISOLATED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 31W-
35W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES THAT SOUTHWEST TO WESTERLY FLOW
ALOFT PERSISTS BETWEEN AN UPPER LEVEL ANTICYCLONE CENTERED NEAR
23N88W AND A MIDDLE TO UPPER LEVEL LOW CENTERED OVER WESTERN
LOUISIANA NEAR 31N94W AND THE ASSOCIATED TROUGH AXIS EXTENDING
SW TO A BASE OVER NORTHERN MEXICO NEAR 25N100W. WEAK MIDDLE TO
UPPER LEVEL DIFFLUENCE N OF 24N W OF 87W IS GENERATING ISOLATED
SHOWERS AND TSTMS ACROSS THIS AREA WITHIN MOIST SOUTHERLY RETURN
FLOW THIS MORNING. THE REMAINDER OF THE GULF IS UNDER THE
INFLUENCE OF THESE E-SE WINDS DUE TO WEAK SURFACE RIDGING
EXTENDING FROM THE MID-ATLC COAST AND SE CONUS TO THE SW GULF
WATERS.

CARIBBEAN SEA...
A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN
NEAR 19N85W AND REMAINS EMBEDDED WITHIN RELATIVELY DRY AIR ALOFT
PROVIDING FOR MOSTLY CLEAR SKIES AND FAIR CONDITIONS W OF 84W
THIS MORNING. TO THE EAST...AN UPPER LEVEL ANTICYCLONE IS
CENTERED NEAR 18N78W AND CONTINUES TO PROVIDE AN OVERALL UPPER
LEVEL DIFFLUENT ENVIRONMENT FOR THE CENTRAL CARIBBEAN AND
PORTIONS OF THE WESTERN CARIBBEAN. AT THE SURFACE ACROSS THIS
AREA...A SURFACE TROUGH IS ANALYZED ALONG 82W WITH A 1008 MB LOW
NOTED ALONG THE AXIS NEAR 16N PROVIDING FOCUS FOR LOW-LEVEL
MOISTURE CONVERGENCE AND SCATTERED SHOWERS AND TSTMS FROM 13N-
22N BETWEEN 76W-84W. THE REMAINDER OF THE CARIBBEAN E OF 72W IS
UNDER THE INFLUENCE OF NORTH-NORTHEASTERLY DRY AND STABLE FLOW
ALOFT PROVIDING FOR MOSTLY CLEAR SKIES AND FAIR CONDITIONS WITH
ONLY MIDDLE TO HIGH LEVEL CLOUDINESS NOTED ON SATELLITE IMAGERY
THIS MORNING.

HISPANIOLA...
CURRENTLY A FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT IS OVER
THE ISLAND AS WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL
ANTICYCLONE IS CENTERED NEAR 18N78W. MOST OF THE MOISTURE NOTED
ON SATELLITE IMAGERY AT THIS TIME IS MIDDLE TO UPPER LEVEL
CLOUDINESS...HOWEVER A FEW LINGERING ISOLATED SHOWERS ARE
POSSIBLE THROUGH THE MORNING HOURS. WHILE MOST OF THE STRONGER
LIFTING DYNAMICS ARE LOCATED TO THE WEST OVER THE WESTERN
CARIBBEAN SEA...EAST-SOUTHEASTERLY TRADES ARE EXPECTED TO REMAIN
IN PLACE FOR TUESDAY WITH AFTERNOON AND EVENING CONVECTION
EXPECTED DUE TO PEAK DAYTIME HEATING AND INSTABILITY.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL LOW IS CENTERED OFF THE NEW ENGLAND
COAST NEAR 40N66W THAT EXTENDS A TROUGH AXIS SOUTHWARD ALONG 62W
TO 25N. THE TROUGHING SUPPORTS A 1006 MB LOW CENTERED NEAR
41N64W WITH A SURFACE TROUGH EXTENDING INTO THE DISCUSSION AREA
NEAR 32N61W TO 29N64W. WITH LARGE-SCALE MOISTURE TRANSPORT AND
LOW-LEVEL MOISTURE CONVERGENCE PRIMARILY EAST OF THE BOUNDARY...
ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF A
LINE FROM 32N56W TO 21N65W. THE REMAINDER OF THE SW NORTH ATLC
WEST OF THE SURFACE TROUGH REMAINS UNDER WESTERLY FLOW ALOFT
EAST OF AN UPPER LEVEL TROUGH AXIS EXTENDING FROM OVER THE
CAROLINA COAST NEAR 35N74W SW TO 30N83W. ISOLATED SHOWERS AND
TSTMS COVER THE AREA W OF 66W. FARTHER EAST...ASIDE FROM
TROPICAL STORM JERRY...THE CENTRAL ATLC IS UNDER THE INFLUENCE
OF A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH CENTERED NEAR
26N57W AND ANOTHER SURFACE RIDGE ACROSS THE EASTERN ATLC
ANCHORED BY A 1017 MB HIGH CENTERED NEAR 24N30W. A COLD FRONT
PASSES ACROSS NORTHEASTERN PORTIONS OF THE DISCUSSION AREA
ANALYZED FROM 32N18W TO 28N30W BECOMING STATIONARY WESTWARD TO
29N41W DUE NORTHEAST FROM TROPICAL STORM JERRY. A FEW ISOLATED
SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT.

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

$$
HUFFMAN


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