[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131802
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE JAN 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS THE GULF OF GUINEA TO 04N14W
WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ CONTINUES WEST ACROSS
THE ATLANTIC FROM 04N14W TO 03N31W TO THE COAST OF FRENCH
GUIANA. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM N OF THE
ITCZ BETWEEN 24W AND 45W.

...DISCUSSION...

GULF OF MEXICO...

A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM COASTAL WATERS OF
NORTH CAROLINA SOUTHWARD ACROSS CUBA TO THE SW CARIBBEAN SEA.
THIS TROUGH CONTINUES TO SUPPORT A FRONTAL SYSTEM ANALYZED AS A
COLD FRONT ACROSS NORTHERN FLORIDA SW TO 29N82W 26N87W TO 24N91W
WHERE IT TRANSITIONS TO A STATIONARY FRONT ALONG 21N95W TO THE
BAY OF CAMPECHE NEAR 18N94W. OVER THE GULF...SHALLOW MOISTURE
BEING ADVECTED FROM THE CARIBBEAN AND THE SW N ATLC WATERS ALONG
WITH A DIFFLUENT ENVIRONMENT ALOFT SUPPORT SCATTERED SHOWERS W
OF THE FRONTAL BOUNDARY EXCEPT FOR THE NW BASIN N OF 28N WHERE
FOG IS BEING REPORTED. MODERATE TO FRESH NORTHERLY FLOW PERSISTS
BEHIND THE FRONT WHILE LIGHTER NORTHEASTERLY TO EASTERLY FLOW
DOMINATES EAST OF THE BOUNDARY. THE PORTION OF THE FRONT ACROSS
THE BASIN WILL WEAKEN TONIGHT THROUGH WED MORNING LEAVING A
SURFACE RIDGING AS THE DOMINANT FEATURE.

CARIBBEAN SEA...

RAINSHOWERS PERSIST ACROSS THE NW CARIBBEAN BEING ENHANCED BY
MIDDLE-LEVEL DIFFLUENCE AND A SHARP UPPER-LEVEL TROUGH WITH BASE
REACHING THE SW BASIN. TRADE WIND FLOW CONTINUES TO DIMINISH
OVER THE CENTRAL AND EASTERN CARIBBEAN AS STRONG HIGH PRES N OF
THE AREA HAS WEAKENED AND SHIFTED EAST. TRADES IN THESE REGIONS
ARE 20-25 KT...DIMINISHING TO 15 KT BY WED MORNING. PASSING
SHOWERS ARE NOTED ACROSS THE LESSER ANTILLES THROUGH PUERTO
RICO.

...HISPANIOLA...

SHALLOW MOISTURE EMBEDDED IN A SLIGHT TO GENTLE BREEZE CONTINUES
TO DELIVER WEAK FAST MOVING SHOWERS ACROSS THE ISLAND. THESE
SHOWERS WILL REMAIN POSSIBLE THROUGH TONIGHT WHEN A DRY AIRMASS
STARTS TO MOVE ACROSS THE ISLAND. DRY AIR SUBSIDENCE ALOFT WILL
PREVENT THE DEVELOPMENT OF DEEP CONVECTION.

ATLANTIC OCEAN...

A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM COASTAL WATERS OF
NORTH CAROLINA SOUTHWARD ACROSS CUBA TO THE SW CARIBBEAN SEA.
THIS TROUGH CONTINUES TO SUPPORT A FRONTAL SYSTEM ANALYZED AS A
COLD FRONT FROM 30N77W SW ACROSS NORTHERN FLORIDA FROM 29N81W TO
28N82W THEN ACROSS THE GULF TO 24N91W WHERE IT TRANSITIONS TO A
STATIONARY FRONT. TROUGHINESS ALOFT SUPPORT A SURFACE TROUGH
ALONG 29N76W TO 23N80W. SCATTERED MODERATE CONVECTION AND TSTMS
ARE WITHIN 120 NM EITHER SIDE OF ITS AXIS...INCLUDING THE
NORTHERN BAHAMAS. ISOLATED SHOWERS ARE OVER THE REMAINDER
BAHAMAS. AN UPPER LOW IS IN THE FAR E ATLC CENTERED NEAR THE
CANARY ISLANDS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM THE
CANARY ISLANDS NEAR 32N15W TO INLAND OVER THE WESTERN SAHARA TO
SENEGAL. THE REMAINDER OF THE BASIN IS DOMINATED BY HIGH
PRESSURE WITH A 1036 MB HIGH CENTERED OVER THE N CENTRAL ATLC
NEAR 32N40W. THIS IS SUPPORTING A BROAD AREA OF FRESH TO STRONG
TRADE WINDS ACROSS THE ATLC BASIN S OF 25N. THE ATLC SURFACE
RIDGE WILL SHIFT E THROUGH TONIGHT. A WEAK FRONT WILL MOVE
THROUGH THE NW WATERS TONIGHT...SLOWLY SHIFTING E AND
DISSIPATING ACROSS THE CENTRAL ATLC WED.

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

$$
NR

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