[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121800
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE NOV 12 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.

...SPECIAL FEATURES...
A COLD FRONT IS EXPECTED TO EMERGE INTO THE NW GULF WATERS
TONIGHT. AS THE COLD FRONT PUSHES ACROSS THE GULF OF MEXICO...
NORTHERLY-NORTHEASTERLY GALE FORCE WINDS/GUSTS ARE EXPECTED TO
DEVELOP WEST OF THE FRONTAL BOUNDARY. SEE LATEST HIGH SEAS
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE
DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR
12N16W TO 10N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 09N21W TO 06N35W 04N49W. ASCAT DATA SHOW THERE IS A
SURFACE TROUGH EMBEDDED WITHIN THE ITCZ AXIS...WHICH AT 1200 UTC
IS ANALYZED FROM 13N40W TO 06N41W. SCATTERED RAINSHOWERS ARE
MAINLY EAST OF THE TROUGH AXIS FROM 09N-12N BETWEEN 33W-40W.
SCATTERED MODERATE CONVECTION AND TSTMS ARE FROM 04N-09N E OF
26W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER-LEVEL RIDGE CENTERED OVER THE NW CARIBBEAN NEAR
18N78W CONTINUES TO PROVIDE SOUTHWEST TO WESTERLY FLOW ALOFT
ACROSS THE GULF WATERS. UPPER-LEVEL DIFFLUENCE BETWEEN THE W-SW
PERIPHERY OF THE RIDGE AND A TROUGH IN THE EAST PACIFIC WITH
AXIS NEAR 110W CONTINUES TO ADVECT MOISTURE OVER GREAT PORTIONS
OF MEXICO AS WELL AS NORTHEASTWARD ACROSS THE GULF. UPPER-LEVEL
DIVERGENCE ALONG WITH LOW-LEVEL MOISTURE CONVERGENCE ALONG A
SURFACE TROUGH ANALYZED FROM 24N93W TO 18N94W IS GENERATING
SCATTERED SHOWERS AND ISOLATED TSTMS MAINLY S OF 26N W OF 85W.
SURFACE RIDGING DOMINATES N OF 26N AS WELL AS WEST OF THE TROUGH
OVER THE BAY OF CAMPECHE WITH NW TO N WIND FLOW IN THE RANGE OF
20-25 KT S OF 25N W OF 95W. A COLD FRONT FOLLOWED BY REINFORCING
SURFACE RIDGING WILL EMERGE TONIGHT INTO THE NW GULF WATERS. AS
THE COLD FRONT PUSHES ACROSS THE GULF OF MEXICO... NORTHERLY-
NORTHEASTERLY GALE FORCE WINDS/GUSTS ARE EXPECTED TO DEVELOP
WEST OF THE FRONTAL BOUNDARY. NOTE SPECIAL FEATURES SECTION
ABOVE...TO THE GULF TUESDAY THROUGH LATE THURSDAY.

CARIBBEAN SEA...
AN UPPER-LEVEL ANTICYCLONE CENTERED OVER THE NW CARIBBEAN NEAR
18N78W INFLUENCES THE NW AND NORTH-CENTRAL BASIN WITH DRY AIR
SUBSIDENCE...THUS FAVORING FOR THE MOST PART FAIR WEATHER. IN
THE FAR NW CARIBBEAN...LOW-LEVEL MOISTURE CONVERGENCE IS
ENHANCING ISOLATED SHOWERS WITHIN 100 NM OF THE YUCATAN
PENINSULA AND BELIZE COASTLINES. LOCALIZED MARGINAL UPPER-LEVEL
DIVERGENCE S OF CENTRAL HISPANIOLA IS ENHANCING SIMILAR
CONVECTION FROM 16N-18N BETWEEN 70W-73W. THE MONSOON TROUGH AXIS
EXTENDS FROM THE E PACIFIC TO COSTA RICA AND PANAMA TO NORTHERN
COLOMBIA. LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH UPPER-LEVEL
DIVERGENCE IS GENERATING SCATTERED MODERATE CONVECTION AND TSTMS
S OF 11N W OF 76W. AN UPPER-LEVEL TROUGH EXTENDS FROM THE
CENTRAL ATLC SW ACROSS THE LESSER ANTILLES TO A BASE OVER
NORTHERN COLOMBIA SUPPORTING ISOLATED SHOWERS ACROSS THE EASTERN
CARIBBEAN. A COLD FRONT IS EXPECTED TO ENTER THE FAR NW BASIN BY
LATE WEDNESDAY TO EARLY THURSDAY.

...HISPANIOLA...
CURRENTLY A FEW ISOLATED SHOWERS OCCURRING OFFSHORE THE SOUTHERN-
CENTRAL ISLAND FROM 16N-18N BETWEEN 70W-73W. OTHERWISE...DRY AND
OVERALL STABLE NORTHERLY FLOW ALOFT IS NOTED ON WATER VAPOR
IMAGERY WHICH IS ANTICIPATED TO LIMIT ANY SIGNIFICANT DEEP
CONVECTION OVER THE NEXT FEW DAYS.

ATLANTIC OCEAN...
WEAK UPPER LEVEL TROUGHING IS NOTED OVER THE CENTRAL ATLC
SUPPORTING SURFACE TROUGHINESS GENERALLY N OF 25N BETWEEN 37W-
80W AS WELL AS A 1018 MB LOW CENTERED NEAR 30N58W. THE SURFACE
TROUGHS ARE PROMOTING LOW-LEVEL MOISTURE CONVERGENCE WITH WIDELY
SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING N OF 25N BETWEEN
45W-70W. THE REMAINDER EASTERN ATLC IS UNDER THE INFLUENCE OF
SURFACE RIDGING ANCHORED BY A 1037 MB HIGH CENTERED WELL NORTH
OF THE DISCUSSION AREA NEAR 49N17W.

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

$$
NR


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