[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 140000
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED MAR 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO
04N19W TO 01N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 01N23W TO EQ30W EQ40W TO THE NORTHERN COAST OF
BRAZIL NEAR 2S44W. WIDESPREAD MODERATE TO ISOLATED STRONG
CONVECTION IS FROM 3N-8N BETWEEN 13W AND 19W WHILE SCATTERED
MODERATE CONVECTION IS FROM THE EQUATOR TO 3N BETWEEN 20W AND
26W.

...DISCUSSION...

GULF OF MEXICO...
IN THE MIDDLE TO UPPER LEVELS...W-SOUTHWESTERLY FLOW SURROUNDING A
RIDGE CENTERED OVER THE CARIBBEAN IS ADVECTING MOISTURE FROM THE E
PACIFIC TO THE GULF. THIS MOISTURE IS SUPPORTING MULTI-LAYERED
CLOUDINESS S OF 26N. AN ENHANCEMENT OF GOES-E IR SATELLITE IMAGERY
INDICATE SCATTERED SHOWERS FROM 20N-24N WEST OF 83W WHILE METAR
OBSERVATIONS INDICATE BROKEN TO OVERCAST SKIES AND HAZE ALONG THE
EAST COAST OF MEXICO INCLUDING THE YUCATAN PENINSULA. AT THE SURFACE
NORTHEASTERLY FLOW DOMINATES THE BASIN. IN TERMS OF WIND
MAGNITUDE... WINDS OF 15 KT DOMINATE WEST OF 91W WHILE STRONGER
WINDS OF 20 KT SPREAD OVER THE EASTERN GULF S OF 27N. OVER THE
COURSE OF 24 HOURS...A SURFACE RIDGE WILL BUILD OVER LOWER
MISSISSIPPI AND LOUISIANA. THIS HIGH PRESSURE OVER THE NORTHERN
GULF WILL MAINTAIN THE NORTHEASTERLY FLOW OVER THE REGION.

CARIBBEAN SEA...
AS OF 2100 UTC...A STATIONARY FRONT ENTERS THE WEST CARIBBEAN
REGION BY CENTRAL CUBA NEAR 22N80W AND EXTENDS ALONG 20N84W
18N86W TO THE NORTHERN COAST OF HONDURAS NEAR 15N87W. BROKEN TO
OVERCAST SKIES ARE ALONG THE STATIONARY FRONT WITH RAINSHOWERS
CONCENTRATING S OF 21N. THE GFS MODEL SIX HOUR TOTAL
PRECIPITATION SUGGEST THE STRONGEST RAINSHOWERS ARE IN THE
COASTAL WATERS OF HONDURAS WHICH IS SUPPORTED BY METAR DATA IN
THE NORTHERN COAST OF HONDURAS. A MIDDLE TO UPPER LEVEL RIDGE IS
OVER THE CENTRAL CARIBBEAN PROVIDING W-SOUTHWESTERLY FLOW WEST
OF 74W AND NORTHWESTERLY FLOW EAST OF THAT MERIDIAN. WATER VAPOR
IMAGERY INDICATES VERY DRY AND STABLE AIR ALOFT E OF 82W WHICH
IS FAVORING FAIR WEATHER CONDITIONS FOR THE REMAINDER BASIN
EXCEPT FOR THE COASTAL WATERS OF PANAMA AND COLOMBIA. SCATTERED
SHOWERS ARE OCURRING ALONG THE COAST OF PANAMA AND COLOMBIA
ENHANCED BY SIGNIFICANT MOISTURE ADVECTION FROM THE EAST PACIFIC
OCEAN. IN TERMS OF WIND...THE SOUTHERN...CENTRAL AND EASTERN
CARIBBEAN IS UNDER THE INFLUENCE OF E-NE TRADEWINDS IN THE RANGE
OF 10 TO 20 KT WITH STRONGER WINDS OF 25 KT OCCURRING ALONG THE
COAST OF COLOMBIA. OVER THE WEST CARIBBEAN...NORTHERLY FLOW OF
20-25 KT IS WEST OF THE STATIONARY FRONT WHILE 5-15 KT WINDS
ABOUNDS EAST OF THE FRONT. WITHIN THE COURSE OF 24 HOURS...THE
FRONT IS EXPECTED TO DRIFT SOUTHEASTWARD BUT REMAIN
APPROXIMATELY 80 NM WEST OF JAMAICA. IN TERMS OF
WINDS...NORTHERLY FLOW WILL SPREAD WEST OF 78W WHILE E-NE
TRADEWINDS WILL PERSIST IN THE REMAINDER OF THE BASIN.

ATLANTIC OCEAN...
IN THE MIDDLE TO UPPER LEVELS...THE EASTERNMOST SIDE OF A BROAD
TROUGH OVER THE EASTERN CONUS N OF 31N IS SUPPORTING A COLD
FRONT THAT ENTERS THE WEST ATLC BY 30N72W AND EXTENDS ALONG
26N75W TO NORTHERN WESTERN CUBA NEAR 22N79W WHERE IT BEACOMES
STATIONARY. SCATTERED SHOWERS ARE WITHIN 180 NM EAST OF THE COLD
FRONT N OF 25N AND WITHIN 90 NM WEST OF THE FRONT S OF 25N.
FARTHER EAST IN THE W ATLC...A SURFACE 1019 MB HIGH IS LOCATED
NEAR 27N64W WHICH IS EXPECTED TO DRIFT SOUTHEASTWARD WITHIN 24
HOURS. IN THE CENTRAL ATLC A 1003 MB LOW IS LOCATED NEAR 27N44W.
AHEAD OF THE LOW A SURFACE TROUGH EXTENDS ALONG 26N37W 20N40W TO
15N45W WHERE IT TRANSITIONS TO A SHEARLINE THAT CONTINUES TO
12N53W TO 10N62W. WIDELY SCATTERED MODERATE CONVECTION
ASSOCIATED TO BOTH THE LOW AND THE TROUGH IS CONFINED TO N OF
20N BETWEEN 33W-43W. BOTH FEAUTURES ARE BEING SUPPORTED BY A
BROAD UPPER LEVEL TROUGH THAT EXTENDS FROM 10N TO 40N IN THE
CENTRAL ATLC. A SURFACE RIDGE DOMINATES ACROSS THE EASTERN ATLC
N OF 19N EAST OF 33W ANCHORED BY A 1016 MB HIGH CENTERED NEAR
28N20W. THIS HIGH IS EXPECTED TO DISSIPATE OVER THE NEXT 24
HOURS WHILE THE LOW OVER THE CENTRAL ATLC DRIFT EASTWARD. THE
COLD FRONT OVER THE W ATLC WILL CONTINUE TO MOVE EASTWARD WHILE
SLIGHTLY WEAKENS.

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

$$
RAMOS

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