[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 151808
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED OCT 15 2014

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
1745 UTC.

...SPECIAL FEATURES...

THE CENTER OF HURRICANE GONZALO AT 15/1800 UTC IS NEAR 23.8N
68.3W OR ABOUT 542 NM S-SW OF BERMUDA. GONZALO IS MOVING TOWARD
THE NORTHWEST OR 320 DEGREES AT 10 KT. THE ESTIMATED MINIMUM
CENTRAL PRESSURE IS 949 MB. THE MAXIMUM ESTIMATED WIND SPEED IS
115 KT WITH GUSTS TO 140 KT. GONZALO IS A CATEGORY FOUR
HURRICANE ON THE SAFFIR-SIMPSON HURRICANE WIND SCALE.
FLUCTUATIONS IN INTENSITY...COMMON IN MAJOR HURRICANES...ARE
LIKELY TO OCCUR WITH GONZALO OVER THE NEXT DAY OR SO. HURRICANE
CONDITIONS ARE POSSIBLE OVER BERMUDA ON FRIDAY...WITH TROPICAL
STORM CONDITIONS POSSIBLE BY LATE THURSDAY NIGHT. NUMEROUS
MODERATE/STRONG CONVECTION IS FROM 21N-26N BETWEEN 65W-70W. FOR
MORE INFORMATION SEE THE PUBLIC ADVISORIES UNDER WMO HEADER
WTNT33 KNHC/AWIPS HEADER MIATCPAT3 AND THE FORECAST/ADVISORIES
ISSUED UNDER WMO HEADER WTNT23 KNHC/AWIPS HEADER MIATCMAT3.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF GUINEA
BISSAU NEAR 11N15W TO 10N16W IN THE FAR E ATLC. THE ITCZ BEGINS
NEAR 10N16W AND CONTINUES ALONG 7N25W TO 9N35W. SCATTERED
MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 2N-10N BETWEEN
16W-31W.

...DISCUSSION...

...THE GULF OF MEXICO...

THE HIGHLIGHT IN THE BASIN CONTINUES TO BE A FRONTAL SYSTEM
ANALYZED AS A COLD FRONT FROM 30N79W SW ACROSS CENTRAL FLORIDA
TO 26N82W AND THEN ALONG 24N85W TO 22N88W WHERE IT TRANSITIONS
TO A STATIONARY FRONT TO THE BAY OF CAMPECHE NEAR 18N92W. THE
FRONT IS BEING SUPPORTED BY A MIDDLE TO UPPER LEVEL ELONGATED
CYCLONIC CIRCULATION OVER THE EASTERN U.S. EXTENDING ACROSS THE
NORTHERN BASIN. SSMI TPW AND WATER VAPOR IMAGERY SHOW A VERY DRY
ENVIRONMENT BEHIND THE FRONT WHICH ALONG STRONG DEEP LAYER
ENVIRONMENTAL WIND SHEAR SUPPORT CLEAR SKIES. AHEAD OF THE FRONT
AND IN THE UPPER LEVELS...A RIDGE ANCHORED OVER GUATEMALA
GENERATES A DIFFLUENT ENVIRONMENT ALOFT WHICH ALONG MOISTURE
ADVECTION FROM THE CARIBBEAN AND THE SW ATLC SUPPORT SCATTERED
MODERATE CONVECTION AND ISOLATED TSTMS WITHIN 100 NM OF THE
BOUNDARY. SURFACE RIDGING CONTINUES TO BUILD BEHIND THE FRONT
BEING ANCHORED BY A 1021 MB HIGH OVER THE COASTLINE OF SOUTHERN
TEXAS. NORTHERLY-NORTHWESTERLY FLOW OF 10-15 KT DOMINATES ACROSS
THE BASIN INCREASING TO 20-25 KT IN THE WESTERN BAY OF CAMPECHE.
THE COLD FRONT WILL DRIFT TOWARDS THE STRAITS OF FLORIDA BY
FRIDAY MORNING WHEN IT IS EXPECTED TO TRANSITION TO A STATIONARY
FRONT DISSIPATING LATER THAT DAY. SURFACE HIGH PRESSURE WILL
DOMINATE ELSEWHERE ACROSS THE GULF.

...THE CARIBBEAN SEA...

EXCEPT THE SW CARIBBEAN SEA...SHALLOW MOISTURE DOMINATES ACROSS
THE REGION. IN THE NORTHERN CENTRAL BASIN...AN UPPER LEVEL LOW
SUPPORT ISOLATED SHOWERS AND TSTMS OVER THE SOUTHERN COASTAL
WATERS OF HISPANIOLA. IN THE NW BASIN...ATMOSPHERIC INSTABILITY
DUE TO AN APPROACHING FRONTAL BOUNDARY PROVIDE FOCUS FOR
ISOLATED SHOWERS AND TSTMS W OF 82W. IN THE SW BASIN...THE
MONSOON TROUGH ENHANCES SCATTERED SHOWERS AND TSTMS S OF 14N.
STRONG DEEP LAYER ENVIRONMENTAL SHEAR ACROSS THE REMAINDER
WESTERN AND CENTRAL BASIN ALONG WITH DRY AIR SUBSIDENCE SUPPORT
FAIR WEATHER. A RELAXED PRESSURE GRADIENT ACROSS THE BASIN
PROVIDES VARIABLE WINDS OF 5-15 KT. A COLD FRONT WILL ENTER THE
FAR NW BASIN THU TO FRI MORNING AND THEN WILL DISSIPATE LATER
THAT DAY AS A STATIONARY FRONT.

...HISPANIOLA...

AN UPPER-LEVEL LOW CENTERED S OF HAITI ALONG WITH SHALLOW
MOISTURE ACROSS THE NORTHERN CARIBBEAN ENHANCES ISOLATED SHOWERS
AND TSTMS ALONG THE SW COAST AND COASTAL WATERS OF THE ISLAND.
NO DEEP CONVECTION IS EXPECTED THROUGH FRI MORNING.

THE ATLANTIC OCEAN...

THE HIGHLIGHT IN THE BASIN IS MAJOR HURRICANE GONZALO CENTERED
NEAR 230 NM E-NE OF THE SOUTHERN BAHAMAS. SEE SPECIAL FEATURES
ABOVE FOR MORE DETAILS. FARTHER WEST IN THE SW N ATLC...A COLD
FRONT IS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS N OF
24N W OF 77W. IN THE CENTRAL BASIN ANOTHER COLD FRONT IS
ANALYZED ALONG 30N33W TO 26N42W TO 24N49W ENHANCING SCATTERED
MODERATE CONVECTION AND TSTMS N OF 23N BETWEEN 39W-49W.

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

$$
NR


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