[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 041745
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON NOV 04 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N14W TO
08N18W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
08N18W TO 03N26W TO 03N38W TO 02N45W. ISOLATED MODERATE
CONVECTION IS FROM 02N-10N BETWEEN 13W-25W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL ANTICYCLONIC FLOW IS NOTED ON WATER VAPOR IMAGERY
OVER MUCH OF THE GULF BASIN THIS AFTERNOON PROVIDING AN OVERALL
STABLE ENVIRONMENT ALOFT. THE UPPER LEVEL RIDGE SUPPORTS SURFACE
RIDGING EXTENDING FROM THE MID-ATLC SW OVER THE SE CONUS TO EAST-
CENTRAL MEXICO NEAR 21N98W. A RELATIVELY STRONG PRESSURE
GRADIENT EXISTS BETWEEN LOWER PRESSURE ACROSS THE CENTRAL
CARIBBEAN SEA AND THE RIDGE PROVIDING FOR NE TO E WINDS IN THE
RANGE OF 20 TO 25 KT E OF 90W. W OF 90W...E WINDS VEER
SOUTHEASTERLY ACROSS THE NW GULF AND REMAIN IN THE RANGE OF 10
TO 20 KT WITH A SMALL POCKET OF 20 TO 25 KT POSSIBLE N OF 27N
THROUGH THE AFTERNOON AND EVENING HOURS AS RETURN FLOW CONTINUES
INTO AN AREA OF DEVELOPING LOW PRESSURE ACROSS THE CENTRAL AND
SOUTHERN U.S. PLAINS. BY LATE WEDNESDAY...THE PRESSURE GRADIENT
ACROSS THE EASTERN GULF IS FORECAST TO RELAX SOMEWHAT WITH THE
NEXT COLD FRONT EXPECTED TO EMERGE OFF THE TEXAS AND LOUISIANA
COASTS BY LATE WEDNESDAY INTO EARLY THURSDAY.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN NEAR 21N83W
THAT EXTENDS A TROUGH AXIS SW TO ANOTHER BROADER UPPER LEVEL LOW
CENTERED OVER GUATEMALA NEAR 15N90W. MIDDLE TO UPPER LEVEL
LIFTING DYNAMICS ASSOCIATED WITH THE UPPER LEVEL LOW CONTINUES
TO GENERATE ISOLATED SHOWERS AND TSTMS ACROSS THE NW CARIBBEAN N
OF 17N W OF 80W...AND IN THE VICINITY OF THE GULF OF HONDURAS.
FARTHER EAST...THE REMAINDER OF THE CENTRAL AND EASTERN
CARIBBEAN ARE UNDER THE INFLUENCE OF AN UPPER LEVEL ANTICYCLONIC
CIRCULATION CENTERED NEAR 18N73W. AT THE SURFACE ON THE WESTERN
PERIPHERY OF THE UPPER LEVEL RIDGE WHERE DIFFLUENCE IS
MAXIMIZED...A 1009 MB LOW IS CENTERED NEAR 17N75W. BROAD FRONTAL
TROUGHING EXTENDS NORTHEAST FROM THE LOW ACROSS EASTERN
CUBA...HISPANIOLA...AND A LARGE PORTION OF THE SW NORTH ATLC
FOCUSED ALONG A SURFACE TROUGH ANALYZED FROM THE LOW CENTER TO
20N73W TO BEYOND 24N67W. SCATTERED SHOWERS AND ISOLATED TSTMS
ARE OCCURRING N OF 15N BETWEEN 68W-77W IN ASSOCIATION WITH THE
SURFACE LOW AND TROUGH AXIS. EAST OF 70W...NORTHERLY FLOW
DOMINATES ON THE EASTERN PERIPHERY OF THE UPPER LEVEL
ANTICYCLONE WITH MIDDLE TO UPPER LEVEL MOISTURE ADVECTING
SOUTHWARD OVER THE EASTERN CARIBBEAN. WITH OVERALL LOW-LEVEL
MOISTURE CONVERGENCE OF E-SE WINDS EAST OF THE AFOREMENTIONED
SURFACE TROUGH AXIS...WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS ARE OCCURRING N OF 13N BETWEEN 59W-68W. FINALLY...THE
MONSOON TROUGH AXIS IS ANALYZED FROM COSTA RICA ALONG 10N TO
11N78W AND IS PROVIDING FOCUS FOR A ISOLATED SHOWERS S OF 12N W
OF 75W THIS AFTERNOON.

HISPANIOLA...
CURRENTLY THE ISLAND IS UNDER THE INFLUENCE OF AN UPPER LEVEL
ANTICYCLONE CENTERED NEAR 18N73W. AT THE SURFACE...A 1009 MB LOW
IS CENTERED SW OF THE ISLAND NEAR 17N75W THAT REMAINS NEARLY
STATIONARY WITH A SURFACE TROUGH ANALYZED NE ACROSS WESTERN
PORTIONS OF HAITI TO BEYOND 22N70W. WIDELY SCATTERED SHOWERS AND
ISOLATED TSTMS ARE ONGOING PRIMARILY ACROSS THE ADJACENT COASTAL
WATERS OF HISPANIOLA...INCLUDING THE WINDWARD PASSAGE. WITH
AMPLE MIDDLE TO UPPER LEVEL DIFFLUENCE AND A WEAK CONVERGENT
SURFACE BOUNDARY FOR THE ATMOSPHERE TO WORK WITH...SHOWERS AND
TSTMS ARE EXPECTED TO CONTINUE THROUGH TUESDAY UNTIL THE SURFACE
LOW DRIFTS WESTWARD AND THE FRONTAL BOUNDARY TO THE NORTH ACROSS
THE SW NORTH ATLC BECOMES MORE DIFFUSE. WITH MAXIMUM DAYTIME
HEATING AND INSTABILITY OCCURRING DURING THE LATE AFTERNOON AND
EARLY EVENING HOURS...CONVECTION IS FORECAST TO PEAK DURING THIS
TIME EACH OF THE NEXT FEW DAYS.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS OVER THE WESTERN
NORTH ATLC FROM 39N63W TO A BASE NEAR 30N74W THAT SUPPORTS A
COLD FRONT ANALYZED FROM 32N62W TO 29N68W WHERE IT BECOMES
STATIONARY TO THE CENTRAL BAHAMAS NEAR 25N77W TO WESTERN CUBA
NEAR 23N81W. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER
SIDE OF THE FRONT. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED TO
THE SOUTHEAST OF THE FRONT FROM 31N63W TO 24N67W TO WESTERN
HISPANIOLA NEAR 20N73W. A LARGE AREA OF FRONTAL TROUGHING IS
NOTED ACROSS THE SW NORTH ATLC AND THIS AREA OF RELATIVELY
WEAKER LOW PRESSURE IS PROVIDING FOR SCATTERED SHOWERS AND
ISOLATED TSTMS N OF 18N BETWEEN 53W-78W...REMAINING GENERALLY IN
THE VICINITY OF AND SOUTH OF THE FRONTAL BOUNDARY. OTHERWISE...
THE REMAINDER OF THE SW NORTH ATLC NW OF THE FRONT IS UNDER THE
INFLUENCE OF SURFACE RIDGING BUILDING IN FROM THE SE CONUS
PROVIDING BRISK NE WINDS IN THE RANGE OF 20 TO 30 KT FROM
BERMUDA WESTWARD TO THE CAROLINAS...GEORGIA...AND FLORIDA
PENINSULA COAST THIS AFTERNOON. FARTHER EAST...A VERY BROAD
COMPLEX UPPER LEVEL LOW IS CENTERED NEAR 23N45W THAT SUPPORTS A
SURFACE TROUGH ANALYZED FROM 11N45W TO 19N43W. ISOLATED SHOWERS
ARE OCCURRING WITHIN 180 NM EITHER SIDE OF THE SURFACE TROUGH
AXIS. THE UPPER LEVEL LOW ITSELF IS GENERATING MULTI-LAYERED
CLOUDINESS AND POSSIBLE ISOLATED SHOWERS ACROSS A LARGE PORTION
OF THE EASTERN ATLC EAST OF A LINE FROM 10N28W TO 22N41W...
PRIMARILY IN THE AREA OF MAXIMUM MIDDLE TO UPPER LEVEL
DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL LOW.

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

$$
HUFFMAN


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