[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 150527
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED MAY 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE COAST OF SIERRA LEONE NEAR
8N13W TO 6N17W. THE ITCZ BEGINS FROM 6N17W AND CONTINUES ALONG
4N30W 2N40W 4N51W. A LARGE CLUSTER OF STRONG CONVECTION IS JUST
MOVING OFF THE COAST OF AFRICA FROM 5N-10N EAST OF 14W.
SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-6N BETWEEN 22W-
37W. SIMILAR ACTIVITY IS FROM 4N-7N BETWEEN 49W-55W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1024 MB
HIGH SOUTH OF THE FLORIDA PANHANDLE NEAR 30N87W. AN UPPER LEVEL
RIDGE ALONG 90W SUPPORTS THE SURFACE RIDGE. CLEAR SKIES ARE
NOTED OVER THE MAJORITY OF THE BASIN EXCEPT FOR THE FAR WESTERN
PORTION ALONG THE MEXICO COAST. WEST OF 95W ISOLATED SHOWERS ARE
POSSIBLE SOUTH OF 27N. LIGHT ANTI-CYCLONIC WINDS ARE IN THE NE
GULF AROUND THE HIGH CENTER INCREASING TO 15 KT ON THE OUTER
PERIMETER...AND REACHING 20 KT ACROSS THE TEXAS COAST. A WEAK
SURFACE TROUGH IS ALSO ANALYZED IN THE SW GULF ALONG 22N93W TO
18N94W. ISOLATED SHOWERS ARE EAST OF THE TROUGH OVER THE YUCATAN
PENINSULA. SURFACE RIDGING WILL CONTINUE TO DOMINATE THE BASIN
FOR AT LEAST THE NEXT SEVERAL DAYS.

CARIBBEAN SEA...
MOSTLY FAIR CONDITIONS SPREAD ACROSS THE CARIBBEAN DUE TO DRY
AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING MUCH OF THE GULF
OF MEXICO CARIBBEAN...AND AN UPPER LEVEL TROUGH WITH AXIS JUST
EAST OF THE LESSER ANTILLES. A FEW ISOLATED SHOWERS ARE NOTED
SOUTH OF WESTERN CUBA...AND ACROSS THE NE CARIBBEAN MOVING
WESTWARD WITH THE TRADEWINDS. ISOLATED SHOWERS ARE ALSO OVER
HISPANIOLA NEAR A WEAK SURFACE TROUGH ALONG 22N68W TO 18N71W.
TRADEWIND FLOW OF 15-20 KT DOMINATES THE MAJORITY OF THE EASTERN
AND CENTRAL CARIBBEAN WITH A FEW 25 KT WINDS NEAR THE COAST OF
COLOMBIA. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS.
ISOLATED TO SCATTERED SHOWERS MAY REMAIN OVER THE NE CARIBBEAN
AS MODEL GUIDANCE INDICATES ENHANCED MOISTURE WILL STAY OVER
THIS AREA.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH ALONG 66W SUPPORTS A COLD FRONT THAT
ENTERS THE DISCUSSION AREA NEAR 32N62W AND CONTINUES TO THE
BAHAMAS NEAR 24N76W...AND DISSIPATES TO 23N79W. A PRE-FRONTAL
SURFACE TROUGH IS EAST OF THE FRONT ALONG 31N62W 23N69W.
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ARE UP TO 250 NM
EAST OF THE TROUGH AXIS NORTH OF 28N. ISOLATED SHOWERS ARE
WITHIN 60 NM OF THE FRONTAL BOUNDARY. A SECOND SURFACE TROUGH IS
THE SOUTH ALONG 22N68W TO 18N71W SUPPORTING ISOLATED SHOWERS
WITHIN 60 NM AS WELL. A RIDGE TROUGH RIDGE PATTERN COVERS THE
REMAINDER OF THE UPPER LEVELS ACROSS THE BASIN. THE FIRST RIDGE
IS NARROW AND ALONG 53W. THE UPPER TROUGH IS ALONG 43W
SUPPORTING A SURFACE TROUGH ALONG 32N41W TO 24N41W. SCATTERED
SHOWERS ARE EAST OF THE TROUGH FROM 28N-31N BETWEEN 34W-41W.
THE SECOND UPPER RIDGE IS BROAD AND COVERS THE MAJORITY OF THE
TROPICAL ATLC. AT THE SURFACE...A BROAD SURFACE RIDGE DOMINATES
THE CENTRAL AND EASTERN ATLC...EXCEPT FOR THE SURFACE
TROUGH...ANCHORED BY A 1040 MB HIGH NEAR 45N41W. FAIR CONDITIONS
SPREAD ACROSS THIS AREA EXCEPT FOR AN AREA OF SHOWERS NEAR THE
SURFACE TROUGH.

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

AT THE REQUEST OF METEO-FRANCE AND THE METEOROLOGICAL 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.

$$
WALTON


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