[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 211739
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE JUN 21 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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
1715 UTC.

...TROPICAL WAVES...

TROPICAL WAVE INTRODUCED OVER THE CENTRAL ATLC ALONG 43W S OF
12N MOVING W NEAR 15 KT. THE WAVE IS LOW AMPLITUDE COMPARED TO
THE WAVES LOCATED FARTHER W...BUT IT IS ASSOCIATED WITH CLUSTERS
OF SHOWERS/TSTMS ORIENTED WITHIN AN E/W BAND NEAR THE ITCZ. THE
POSITION IS BASED ON ELEVATED WAVE PASSAGE AT DAKAR EARLY ON
JUNE 17...GIVING IT A MEAN MOTION OF NEAR 15 KT. SEE ITCZ FOR
RELATED CONVECTION.

TROPICAL WAVE CROSSING THE LESSER ANTILLES ALONG 60W/61W S OF
19N MOVING W 20 KT. NEW UPPER AIR DATA FROM BARBADOS AND
GUADELOUPE INDICATE THAT A DEEP-LAYERED PERTURBATION PASSED BOTH
ISLANDS BETWEEN 1200 UTC YESTERDAY AND 1200 TODAY...WHICH LEADS
ME TO BELIEVE THE WAVE AXIS IS A LITTLE FARTHER W...PROBABLY
CLOSER TO 63W/64W. THIS WILL BE REFLECTED ON THE NEXT SFC
ANALYSIS. MOST OF THE SHOWERS/TSTMS HAVE MOVED W OF THE
LEEWARD/WINDWARD ISLANDS WITH SCATTERED MODERATE CONVECTION FROM
13N-16N BETWEEN 62W-67W. THE WAVE IS EXPECTED TO DRAW DEEP
TROPICAL MOISTURE NWD IN ITS WAKE...WHICH WILL ALLOW SCATTERED
SHOWERS/TSTMS TO BEGIN SPREADING OVER HISPANIOLA ON WED AND THEN
ACROSS THE BAHAMAS BEGINNING ON THU.

CENTRAL CARIBBEAN TROPICAL WAVE ALONG 72W S OF 19N MOVING W
15-20 KT. THE WAVE LIES ON THE DOWNSHEAR SIDE OF A MID/UPPER LOW
WHICH IS ROTATING SLOWLY WWD OVER THE CARIBBEAN...AND THIS IS
KEEPING ALL ASSOCIATED CONVECTION TO THE E OF THE AXIS ALIGNED
MORE OR LESS ALONG AN E/W BAND. WIDELY SCATTERED MODERATE
CONVECTION FROM 15N-17N BETWEEN 67W-74W.

TROPICAL WAVE CROSSING CENTRAL AMERICA ALONG 86W S OF 19N MOVING
W 20 KT. THE MOST PRONOUNCED CIRCULATION ASSOCIATED WITH THE
WAVE IS LOCATED OVER THE E PACIFIC SW OF COSTA RICA...BUT IT
DOES APPEAR THE AXIS EXTENDS N OF THIS AREA TO THE GULF OF
HONDURAS BASED ON SHOWERS/TSTMS APPROACHING THE YUCATAN COAST.
WIDELY SCATTERED MODERATE EXTENDS FROM ERN NICARAGUA AND
HONDURAS NWWD TO NEAR CANCUN AND COZUMEL...OR FROM 12N-21N
BETWEEN 84W-88W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 14N10W 8N30W 9N40W 7N48W
12N60W...THEN ALONG 10N61W 13N71W...THEN ALONG 12N73W 8N85W.
ISOLATED SHOWERS/TSTMS 240 NM S OF THE AXIS BETWEEN 14W-23W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 4N-11N
BETWEEN 36W-58W...MOVING INLAND BETWEEN FRENCH GUIANA AND GUYANA.

...DISCUSSION...

GULF OF MEXICO...
A NEARLY STATIONARY CLOSED LOW OVER THE SRN APPALACHIANS
CONTINUES TO KEEP THE OVERALL WEATHER PATTERN QUITE STAGNANT
WITH A MID/UPPER LEVEL TROF EXTENDING TO THE SW FROM THE FL
PANHANDLE TO NEAR 24N91W IN THE CNTRL GULF. THE TROF IS STILL
PULLING LARGE AMOUNTS OF TROPICAL MOISTURE FROM SRN MEXICO AND
THE BAY OF CAMPECHE NEWD ACROSS THE YUCATAN CHANNEL...W CUBA...
AND S FLORIDA ON THE EQUATORWARD SIDE OF A STRONG 90-100 KT
SUBTROPICAL JET THAT RIDES UP TO THE CAROLINA COAST. THIS REGION
LIES WITHIN THE RIGHT REAR QUADRANT OF THE JET...AND IS
INTERACTING WITH A SFC TROF WHICH EXTENDS FROM CNTRL FLORIDA AND
THE E GULF SW TO THE BAY OF CAMPECHE. AS SUCH...CLUSTERS OF
SCATTERED MODERATE CONVECTION ARE DEVELOPING OVER THE SE GULF
WATERS FROM 21N-28N BETWEEN 83W-88W AND WILL BEGIN TO SPREAD
OVER S/CNTRL FLORIDA LATER TODAY...OVER SOME OF THE SAME AREAS
WHICH RECEIVED SEVERAL INCHES OF RAIN YESTERDAY. FLOODING...
ESPECIALLY IN URBAN AREAS...WILL CONTINUE TO BE A CONCERN
THROUGH THE REST OF TODAY AND POSSIBLY TOMORROW. THE DEEP
MOISTURE AXIS SHOULD BEGIN TO DIMINISH ON WED WHICH WILL ALLOW
FOR SOME DRIER WEATHER BY THE END OF THE WEEK. ELSEWHERE...
SCATTERED MODERATE CONVECTION IS ALSO LOCATED AT THE TAIL END OF
THE SFC TROF OVER THE BAY OF CAMPECHE FROM 19N-22N BETWEEN
92W-97W WITH SHOWERS/TSTMS SPREADING INLAND OVER COASTAL MEXICO
FROM TAMPICO TO VERACRUZ.

CARIBBEAN...
A MID/UPPER LEVEL LOW IS CENTERED SW OF HAITI NEAR 15N75W AND IS
MOVING W NEAR 10 KT. THE LOW IS PULLING MID/UPPER LEVEL MOISTURE
NWD ON ITS ERN SIDE...WHICH IS ALLOWING CONVECTION TO DEVELOP
PRIMARILY OVER THE E CARIBBEAN IN THE VICINITY OF TWO TROPICAL
WAVES. THE W CARIBBEAN GENERALLY LIES WITHIN THE SUBSIDENT SIDE
OF THE LOW WITH FAIR SKIES N OF 13N SPREADING OVER
JAMAICA...CUBA...AND THE CAYMAN ISLANDS. DIFFLUENT UPPER LEVEL
FLOW OVER THE SW CARIBBEAN IS PRODUCING SCATTERED MODERATE
CONVECTION FROM 9N-13N BETWEEN 77W-82W WHERE STRONG EASTERLY
TRADE WIND FLOW IS CONVERGING ON WEAK VARIABLE FLOW NEAR THE
PANAMA COAST. DEEPER EASTERLY FLOW WILL BEGIN TO DEVELOP OVER
THE NEXT 48-72 HRS AS THE UPPER LOW WASHES OUT...AND A
CORRESPONDING INCREASE IN MOISTURE ACROSS THE ENTIRE CARIBBEAN
WILL ALLOW FOR MORE EVENLY DISTRIBUTED SHOWERS/TSTMS EXCEPT FOR
HEAVIER TSTMS NEAR TROPICAL WAVES.

ATLANTIC...
THE TROPICAL MOISTURE PLUME ORIGINATING OVER THE GULF OF MEXICO
SPANS ACROSS FLORIDA AND COVERS MUCH OF THE FAR WRN ATLC...N OF
THE BAHAMAS. THE PLUME IS MOSTLY ASSOCIATED WITH OVERCAST
MID/UPPER LEVEL CLOUDINESS BUT FLORIDA RADAR DOES SUGGEST SOME
EMBEDDED WIDELY SCATTERED SHOWERS W OF 75W. STRONG UPPER LEVEL
RIDGING IS CENTERED ALONG 67W WITH A 1023 MB HIGH LOCATED S OF
BERMUDA NEAR 29N66W. FARTHER E...A COLD/STATIONARY FRONT IS
LOCATED ALONG 31N/32N BETWEEN 40W-60W WITH A PRE-FRONTAL TROF
ALONG 28N52W 31N43W...AND THERE ARE ISOLATED SHOWERS NEAR THIS
BOUNDARY N OF 28N BETWEEN 40W-50W. A CUT-OFF MID/UPPER LOW IS
LOCATED FARTHER SE NEAR 22N41W WITH THE SUBTROPICAL JET
UNDERCUTTING THIS FEATURE ALONG 17N60W 15N45W 22N30W. MOISTURE
IS GENERALLY LIMITED E OF THE LOW WITH VERY LITTLE HIGH LEVEL
CLOUDS OBSERVED NEAR AFRICA. IN FACT...THE LOW LEVELS ARE ALSO
QUITE DRY WITH A SAHARAN DUST LAYER OBSERVED BETWEEN THE ITCZ
AND 21N BETWEEN AFRICA AND THE CARIBBEAN.

$$
BERG


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