[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 012345
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE MAY 01 2012

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 2335 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE NRN COAST OF GUINEA NEAR
11N15W TO 6N16W TO 3N21W...WHERE THE ITCZ AXIS CONTINUES ALONG
1N32W TO THE COAST OF BRAZIL NEAR 2S45W. SCATTERED MODERATE TO
STRONG CONVECTION MOVES OFF THE COAST OF LIBERIA AND SIERRA
LEONE E OF 15W. ISOLATED WEAK CONVECTION IS WITHIN 140 NM ON
EITHER SIDE OF THE ITCZ BETWEEN 22W-40W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE TROUGH MOVES ACROSS THE N-CENTRAL GULF THIS EVENING
...ANALYZED FROM 29N86W TO 24N89W. SCATTERED WEAK TO MODERATE
SHOWERS AND ISOLATED THUNDERSTORMS EXTEND UP TO 130 NM FROM
EITHER SIDE OF THE TROUGH AXIS. MOST OF THIS ACTIVITY IS HEADING
TO THE LOUISIANA AND MISSISSIPPI COAST E OF 92W INDICATED BY
DOPPLER RADAR IMAGERY. LAST VISIBLE SATELLITE PICTURES OF THE
DAY SHOWED A MID-LEVEL CYCLONIC CIRCULATION ALONG THE TROUGH
AXIS NEAR 26N89W. HOWEVER...THE CLOUD PATTERN INDICATED THE
CIRCULATION WAS OPENING AS THIS FEATURE LOOSES UPPER LEVEL
SUPPORT...AND WESTERLY ZONAL FLOW ALOFT SETTLES ACROSS THE AREA
ON WATER VAPOR IMAGERY. FAIR WEATHER CONDITIONS ARE ELSEWHERE
ACROSS THE REMAINDER OF THE GULF. MARINE OBSERVATIONS SHOW ESE
WINDS 10-20 KT ACROSS THE AREA...GUSTING TO 25 KT IN THE
VICINITY OF THE SURFACE TROUGH. THIS FEATURE IS EXPECTED TO
CONTINUE TO TRACK NW TO INLAND OVER THE SOUTHERN STATES AND
LEAVING A TRAIL OF LINGERING ISOLATED MODERATE TO HEAVY SHOWERS
OVER THE NE AND N-CENTRAL GULF BASINS LASTING THROUGH FRIDAY.

CARIBBEAN SEA...
MOST OF THE CARIBBEAN BASIN IS UNDER MIDDLE TO UPPER LEVEL
SUBSIDENCE AND DRY AIR ON WATER VAPOR IMAGERY THIS EVENING...
ESPECIALLY OVER THE NW BASIN. HOWEVER...TOTAL PRECIPITABLE WATER
IMAGERY INDICATES MODERATE TO HIGH VALUES OF MOISTURE ENTERING
THE ERN BASIN...WHERE A BROAD AREA OF TROUGHINESS IS OBSERVED IN
THE EASTERLY FLOW PATTERN ACROSS THIS REGION. LOW LEVEL
CONVERGENCE COMBINED WITH PLENTY OF LOW LEVEL MOISTURE IS
GENERATING SCATTERED SHOWERS AND THUNDERSTORMS N OF 14N E OF 68W
INCLUDING THE WATERS NEAR THE LESSER ANTILLES. SIMILAR ACTIVITY
REMAINS OVER THE SRN COASTAL WATERS OF CUBA WITHIN 50-80 NM
BETWEEN 74W-82W. THE MONSOON TROUGH EXTENDS NEAR THE COASTAL
WATERS FROM COSTA RICA TO NRN COLOMBIA ALONG 10N. MOST OF THE
ACTIVITY ASSOCIATED TO THIS FEATURE REMAINS INLAND. SHORT RANGE
COMPUTER MODELS SUGGEST THE ACTIVITY OVER THE N-ERN CARIBBEAN
WILL SLOWLY INCREASE AND EXPAND DURING THE NEXT 24-48 HRS.

ATLANTIC OCEAN...
A WEAK UPPER LEVEL SHORTWAVE SLOWLY MOVES ACROSS THE FAR SW
NORTH ATLC GENERATING A BROAD AREA OF SCATTERED SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS S OF 27NW OF 65W...WITH THE
HEAVIEST CONCENTRATION OF SHOWER ACTIVITY OVER THE SE BAHAMAS
AND TURKS AND CAICOS ISLANDS. COMPUTER MODELS HAVE SOME
DISAGREEMENTS REGARDING HOW LONG THIS AREA OF CONVECTION WILL
REMAIN ACROSS THE AREA...ESPECIALLY OVER THE HEAVIEST ACTIVITY
MENTIONED ABOVE. A COLD FRONT ENTERED THE DISCUSSION AREA THIS
AFTERNOON...EXTENDING ALONG 30N50W TO 28N55W TO 30N64W.
SCATTERED WEAK SHOWERS ARE OBSERVED WITHIN 30 NM ON EITHER SIDE
OF THE FRONT. THE ACTIVITY IS SUPPORTED ALOFT BY A SHORTWAVE
TRACKING SE INTO THE AREA ALONG 27N55W. A SURFACE TROUGH IS
LOCATED SE OF THE FRONTAL BOUNDARY...ANALYZED FROM 29N48W TO
22N52W WITHOUT ANY SHOWER ACTIVITY. THE REMAINDER OF THE ATLC
BASIN IS UNDER THE INFLUENCE OF SURFACE RIDGING ACROSS THE AREA
E OF 44W.

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

$$

GARCIA




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