[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040018
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAY 03 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 09N14W TO
06N18W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
06N18W TO THE EQUATOR NEAR 34W. WIDELY SCATTERED MODERATE
CONVECTION IS S OF 02N BETWEEN 12W-19W. ISOLATED MODERATE
CONVECTION IS S OF 05N BETWEEN 29W-39W.

...DISCUSSION...

GULF OF MEXICO...
GENERALLY DRY AIR AND WESTERLY UPPER LEVEL FLOW DOMINATE OVER
THE GULF THIS EVENING...HOWEVER A VIGOROUS MIDDLE TO UPPER LEVEL
LOW IS CENTERED NEAR 36N94W OVER NE OKLAHOMA AND NW ARKANSAS
THAT SUPPORTS A COLD FRONT ANALYZED INTO THE BASIN NEAR THE
MISSISSIPPI DELTA REGION EXTENDING SOUTH TO THE YUCATAN
PENINSULA NEAR 21N90W AND ALONG THE SOUTHERN MEXICO COAST TO
18N92W. WHILE THE ATMOSPHERE REMAINS FAIRLY DRY ALOFT...ONLY A
FEW ISOLATED SHOWERS ARE OCCURRING N OF 27N WITHIN 60 NM EITHER
SIDE OF THE FRONT. TO THE EAST...WATER VAPOR INDICATES A MIDDLE
TO UPPER LEVEL SHORTWAVE TROUGH LOCATED ON THE SOUTHEASTERN
PERIPHERY OF THE MAIN UPPER LEVEL LOW OVER THE CENTRAL CONUS.
THIS SHORTWAVE SUPPORTS A BROAD AREA OF LOWER PRESSURE ACROSS
THE EASTERN GULF...FLORIDA PENINSULA...AND A PORTION OF THE SW
NORTH ATLC. SATELLITE IMAGERY AND SURFACE OBSERVATIONS NEAR THE
FLORIDA PENINSULA COAST INDICATE A 1006 MB LOW IS CENTERED NEAR
28N80W WITH A SURFACE TROUGH EXTENDING S-SW ALONG 24N81W AND
INTO THE NW CARIBBEAN SEA. A WEAKER SECONDARY 1009 MB LOW IS
CENTERED NEAR 29N85W AND IS QUICKLY BECOMING ABSORBED INTO THE
LOW TO THE EAST. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE
OCCURRING IN THE VICINITY OF THE LOW ACROSS INLAND PORTIONS OF
THE FLORIDA PENINSULA. ADDITIONAL ISOLATED SHOWERS ARE OCCURRING
PRIMARILY E OF 85W. THE REMAINDER OF THE GULF WEST OF THE COLD
FRONT IS UNDER THE INFLUENCE OF STRONG NORTHERLY WINDS AS
SURFACE RIDGING BUILDS IN FROM THE SOUTHERN PLAINS AND ALONG THE
EASTERN MEXICO COAST. THE AREA OF LOW PRESSURE OVER THE EASTERN
GULF AND FLORIDA PENINSULA WILL BE SLOW TO MOVE NORTHWARD OVER
THE WEEKEND AND IS FORECAST TO EVENTUALLY EXIT THE REGION BY
WEDNESDAY OF NEXT WEEK.

CARIBBEAN SEA...
WEST-SOUTHWESTERLY MIDDLE TO UPPER LEVEL FLOW IS OVER MUCH OF
THE CARIBBEAN THIS EVENING AS THE OVERALL SURFACE PRESSURE
PATTERN REMAINS RELAXED AND SLIGHTLY MODIFIED FROM THE USUAL E-
NE TRADE WIND FLOW. A LARGE AREA OF SURFACE TROUGHING IS
ESTABLISHED OVER THE EASTERN GULF...FLORIDA PENINSULA...AND SW
NORTH ATLC WHICH STRETCHES SOUTHWARD AND COVERS THE BASIN. WEAK
SOUTHERLY WINDS ARE NOTED E OF 80W AS ISOLATED SHOWERS REMAIN
POSSIBLE THROUGH THE OVERNIGHT HOURS. THE ONLY AREA OF SCATTERED
SHOWERS AND TSTMS OCCURRING THIS EVENING IS LOCATED OVER THE SW
CARIBBEAN S OF 16N W OF 78W...INCLUDING INLAND PORTIONS OF
NICARAGUA AND COSTA RICA. AN APPROACHING COLD FRONT CURRENTLY
OVER THE GULF OF MEXICO WILL PROVIDE FOR N-NW WINDS TO FILTER IN
ACROSS THE WESTERN CARIBBEAN OVER THE WEEKEND. MEANWHILE WEAK
SURFACE RIDGING WILL MAINTAIN ITS POSITION OVER THE EASTERN
CARIBBEAN E OF 70W.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR
IMAGERY WITH AXIS EXTENDING FROM OVER THE SE CONUS TO NEAR
29N79W. IT SUPPORTS A 1006 MB LOW CENTERED OFF THE FLORIDA
PENINSULA COAST NEAR 28N80W. A STATIONARY FRONT REMAINS ANALYZED
FROM THE LOW CENTER E-SE ALONG 25N74W TO 23N58W. A SURFACE
TROUGH IS ALSO ANALYZED FROM THE LOW CENTER S-SW ACROSS THE
SOUTHERN FLORIDA PENINSULA AND FLORIDA STRAITS NEAR 24N81W INTO
THE NW CARIBBEAN SEA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE
OCCURRING OVER MUCH OF THE SW NORTH ATLC WATERS THIS EVENING
REMAINING MOSTLY N OF 22N W OF 60W IN ASSOCIATION WITH THE
FRONTAL BOUNDARY. FARTHER EAST...A BROAD AND COMPLEX MIDDLE TO
UPPER LEVEL LOW IS CENTERED NEAR 37N59W WITH SEVERAL WAVES OF
ENERGY ROTATING AROUND THE MEAN CENTER. THIS UPPER LEVEL FEATURE
SUPPORTS A VERY BROAD AREA OF SURFACE LOW PRESSURE CENTERED ON A
1009 MB LOW CENTERED NEAR 33N46W. A SURFACE TROUGH EXTENDS S-SW
FROM THE LOW TO 26N50W TO 23N57W AND MARRIES UP WITH THE
STATIONARY FRONT IN THE SW NORTH ATLC. SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING WITHIN A LARGE AREA TO THE EAST OF
THE SURFACE TROUGH FROM 20N-32N BETWEEN 35W-50W...AND WITHIN 240
NM EITHER SIDE OF THE SURFACE TROUGH W OF 50W. FINALLY...A
SURFACE RIDGE IS MAINTAINING CONTROL OVER THE EASTERN ATLC
ANCHORED BY A 1020 MB HIGH CENTERED NEAR 26N29W.

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

AT THE REQUEST OF METEO-FRANCE AND THE METEROLOGICAL SERVICES OF
HAITI AND THE DOMINICAN REPUBLIC...THE TROPICAL ANALYSIS AND
FORECAST BRANCH (TAFB) WILL BEGIN PROVIDING...ON A TEMPORARY
BASIS...A SEPARATE DETAILED SECTION WITHIN THE ATLANTIC TROPICAL
WEATHER DISCUSSION (TWDAT). IT WILL COVER BOTH HAITI AND THE
DOMINICAN REPUBLIC DUE TO THE SHARED GEOGRAPHY OF BOTH COUNTRIES
ON THE ISLAND OF HISPANIOLA.

THE SECTION BEGINS ON MAY 15 2013 AT 1800 UTC...2 PM EDT. IT
WILL PROVIDE GUIDANCE FOR SIGNIFICANT WEATHER EVENTS THAT ARE
EXPECTED TO IMPACT THE REGION THROUGH 48 HOURS...WITH THE FOCUS
ON ASSESSING THE POTENTIAL FOR HEAVY RAINFALL.

$$
HUFFMAN

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