[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 230002
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 22 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

TROPICAL STORM JOSE CENTERED NEAR 19.7N 95.7W...OR 40 NM NE OF
VERACRUZ MEXICO...AT 23/0000 UTC MOVING W 6 KT. MAXIMUM
SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 1002 MB. SEE LATEST NHC FORECAST/
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND THE
PUBLIC ADVISORY UNDER HEADERS MIATCPAT1/WTNT31 KNHC FOR MORE
DETAILS. JOSE HAS A FAIRLY SMALL CIRCULATION HIGHLIGHTED BY
SEVERAL BURSTS OF CONVECTION WITHIN ABOUT 40 NM OF THE CENTER...
AND THEN A BAND OF TSTMS WHICH WRAPS AROUND THE W AND N SIDES.
SCATTERED MODERATE CONVECTION FROM 18N-22N BETWEEN 93W-99W.
MEXICAN RADAR IMAGERY FROM ALVARADO...NEAR VERACRUZ...SHOWS A
BATCH OF HEAVY RAINS ALREADY OVER THE STATE OF VERACRUZ MOVING
INTO THE MOUNTAINS. JOSE IS EXPECTED TO MOVE INLAND LATER THIS
EVENING AND WEAKEN BUT WILL STILL HAVE THE POTENTIAL TO PRODUCE
FLASH FLOODING OVER PARTS OF CENTRAL AND SOUTHERN MEXICO.

A SURFACE TROF EXTENDS FROM THE WINDWARD PASSAGE NEWD ACROSS THE
SOUTHERN BAHAMAS TO 25N71W AND IS MOVING NW 5-10 KT. THE
LOW-LEVEL FLOW IS NOT PARTICULARLY SHARP...AND THE SYSTEM IS
COLLOCATED BENEATH A MID/UPPER LOW LOCATED NEAR 26N71W WHICH
ALSO HAPPENS TO BE MOVING WWD TOWARDS THE BAHAMAS. SCATTERED
MODERATE CONVECTION IS LOCATED PRIMARILY E OF THE SURFACE TROF
FROM 18N-26N BETWEEN 67W-74W...OVER HISPANIOLA...THE TURKS AND
CAICOS ISLANDS...AND SOUTHERN BAHAMAS. DESPITE THE PRESENCE OF
THE UPPER LOW...NEITHER THE DEEP-LAYERED NOR MID-LEVEL VERTICAL
SHEAR APPEARS THAT DETRIMENTAL. TWO MODELS...THE GFS AND
ECMWF...HAVE BEEN DEVELOPING A SURFACE LOW FROM THIS TROF NEAR
CUBA OR THE BAHAMAS OVER THE NEXT DAY OR SO...SO TROPICAL
CYCLONE DEVELOPMENT APPEARS POSSIBLE WITHIN THE NEXT 36 HRS.

A 1008 MB LOW IS CENTERED ABOUT 420 NM W OF THE CAPE VERDE
ISLANDS NEAR 16N33W...ALONG A TROPICAL WAVE S OF 22N MOVING W
15-20 KT. THE LOCATION OF THE LOW HAS BECOME BETTER DEFINED
SINCE YESTERDAY...ALTHOUGH THE CIRCULATION APPEARS ELONGATED
ALONG 19N30W TO 16N37W. CONVECTION IS QUITE MEAGER SINCE THE
SYSTEM APPEARS TO BE EMBEDDED IN A STABLE DRY LAYER N OF 14N.
ISOLATED SHOWERS/TSTMS ARE FROM 13N-18N BETWEEN 29W-37W WHERE
MOISTURE IS BEING PULLED UP THE E SIDE OF THE CIRCULATION. THE
LOW CONTINUES TO BE LOCATED IN A LOW SHEAR ENVIRONMENT AND IS
OVER WATERS WARM ENOUGH TO SUPPORT A TROPICAL CYCLONE...SO
TROPICAL DEVELOPMENT IS POSSIBLE WITHIN THE NEXT 36 HRS.

...TROPICAL WAVES...

SEE SPECIAL FEATURES FOR TROPICAL WAVE/LOW ALONG 32W/33W.

TROPICAL WAVE LOCATED ABOUT 200 NM E OF BARBADOS ALONG 56W S OF
19N MOVING W 15-20 KT. THE WAVE HAS A FAINT SIGNATURE
CHARACTERIZED PRIMARILY BY A SPECKLING OF TRADE WIND SHOWERS
FROM 11N-16N BETWEEN 54W-58W.

CENTRAL/WEST CARIBBEAN TROPICAL WAVE ALONG 79W S OF 20N MOVING W
15 KT. THE NORTHERN PART OF THE WAVE DETACHED LAST NIGHT FROM
THE WINDWARD PASSAGE NEWD INTO THE W ATLC...WHILE THE MAIN PART
HAS CONTINUED ON TO THE W. SATELLITE IMAGERY SHOWS A WEAK
CIRCULATION OVER THE SW CARIBBEAN WATERS WITH A GENERAL VOID IN
DEEP CONVECTION. SCATTERED MODERATE CONVECTION DOES EXTEND FROM
OVER PANAMA SWD INTO THE E PACIFIC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 15N17W 19N30W...THEN ALONG 11N33W
13N54W. SCATTERED MODERATE CONVECTION WITHIN 120 NM OF A LINE
FROM 14N8W 11N20W 16N24W...SOME OF WHICH IS MOVING OVER THE SE
CAPE VERDE ISLANDS. ISOLATED SHOWERS/TSTMS FROM 6N-12N BETWEEN
36W-49W.

...DISCUSSION...

GULF OF MEXICO...
A STRONG MID/UPPER LEVEL HIGH IS CENTERED INLAND OVER SRN
MISSISSIPPI AND LOUISIANA WHICH IS PRODUCING 30-45 KT EASTERLY
FLOW IN THE UPPER LEVELS ACROSS FLORIDA AND THE N HALF OF THE
GULF. NUMEROUS TSTMS HAVE BROKEN OUT N OF 30N FROM BILOXI
MISSISSIPPI NEWD INTO THE CAROLINAS DUE TO WEAK SURFACE
TROUGHING...AND SOME OF THIS ACTIVITY COULD OCCASIONALLY MAKE
ITS WAY OVER THE FAR NE GULF WATERS. FARTHER S...TROPICAL STORM
JOSE HAS FORMED OVER THE WRN BAY OF CAMPECHE AND IS CENTERED
JUST TO THE W OF AN INVERTED UPPER LEVEL TROF WHICH EXTENDS
ACROSS THE ISTHMUS OF TEHUANTEPEC FROM 21N95W SWD TO 14N94W.
OTHERWISE...JOSE IS PRODUCING ITS OWN SMALL AREA OF OUTFLOW WITH
AN UPPER ANTICYCLONE FORMING NEAR 21N95W. MOISTURE VALUES WILL
REMAIN HIGH OVER THE GULF FOR AT LEAST THE NEXT 48 HRS...WHICH
WILL SUPPORT SCATTERED AREAS OF CONVECTION ESPECIALLY OVER THE
NRN GULF AND NEAR T.S. JOSE.

CARIBBEAN...
AN INVERTED UPPER LEVEL TROF IS LOCATED OVER THE NW CARIBBEAN
FROM THE E TIP OF HONDURAS NWD TO THE YUCATAN CHANNEL...MOVING
SLOWLY WWD TOWARDS BELIZE/YUCATAN COAST. WIDELY SCATTERED
SHOWERS/TSTMS WERE LOCATED BENEATH THE TROF EARLIER IN THE DAY
BUT SINCE DISSIPATED IN FAVOR OF DAYTIME CONVECTION INLAND OVER
CUBA AND THE YUCATAN PENINSULA. OTHER NUMEROUS MODERATE/STRONG
CONVECTION HAS DEVELOPED INLAND OVER WRN NICARAGUA...COSTA
RICA...AND PANAMA ON THE W SIDE OF A BROAD UPPER LOW WHICH IS
CENTERED N OF COLOMBIA NEAR 13N77W. A WEAK UPPER HIGH IS
CENTERED BETWEEN JAMAICA AND CUBA AND IS DRAGGING UPPER LEVEL
MOISTURE SWD OVER HISPANIOLA FROM THE CONVECTION NEAR THE SRN
BAHAMAS. FARTHER E...A SFC TROF EXTENDS FROM NEAR ST. VINCENT
NWWD TO PUERTO RICO MOVING W 10-15 KT AND IS PRODUCING ISOLATED
SHOWERS/TSTMS OVER THE LESSER ANTILLES FROM 13N-20N BETWEEN
59W-68W. THIS MOISTURE IS EXPECTED TO LINGER OVER THE ISLANDS
THROUGH TOMORROW...BUT THEN SHOULD SHIFT W OVER OPEN WATERS BY
WED.

WEST ATLANTIC...
UPPER RIDGE AXIS EXTENDS FROM GEORGIA NEWD OFF THE OUTER BANKS
OF NORTH CAROLINA WITH BROAD NE/E FLOW EXTENDING FROM N OF THE
BAHAMAS TO FLORIDA. A FAIRLY SIZEABLE UPPER LOW IS TUMBLING WWD
TOWARDS THE BAHAMAS NEAR 26N71W AND IS KICKING UP CONVECTION TO
ITS E NEAR A SFC TROF. SCATTERED MODERATE CONVECTION EXTENDS
FROM THE FLORIDA STRAITS EWD PAST THE TURKS AND CAICOS ISLANDS
FROM 20N-26N BETWEEN 67W-81W. THIS MOISTURE IS EXPECTED TO
CONTINUE MOVING NW TOWARDS FLORIDA OVER THE NEXT SEVERAL DAYS
WITH THE POSSIBLE DEVELOPMENT OF A SFC LOW...AS DESCRIBED ABOVE
IN SPECIAL FEATURES.

EAST/CENTRAL ATLANTIC...
STRONG SUBTROPICAL RIDGING EXTENDS N OF 20N WITH MOSTLY DRY AIR
IN THE MIDDLE AND UPPER LEVELS OVER THE ENTIRE AREA. AN UPPER
LOW LOCATED N OF THE AREA NEAR 35N50W IS PULLING SOME MOISTURE
SWD PAST 30N...AND HAPPENS TO BE INITIATING WIDELY SCATTERED
MODERATE CONVECTION N OF 28N BETWEEN 49W-53W. THE UPPER RIDGE
EXTENDS FROM THE COAST OF MAURITANIA WWD ALONG 20N...THEN SWWD
TO 17N60W NEAR THE SRN LEEWARD ISLANDS. THE FLOW IS DEEP
EASTERLY S OF THE RIDGE...BUT AN INVERTED TROF (PROBABLY THE
UPPER LEVEL REFLECTION OF THE STRONG E ATLC TROPICAL WAVE) IS
ALONG 32W AND IS INFLECTING MOISTURE NWD OVER THE E ATLC WATERS.
A SECOND CUT-OFF MID/UPPER LOW IS CENTERED ABOUT 270 NM W OF THE
CANARY ISLANDS NEAR 29N23W AND APPEARS TO BE DRIFTING SLOWLY S.
A PLUME OF SAHARAN DUST EXTENDS W OF WESTERN SAHARA TO ABOUT 45W
BETWEEN 20N-29N...SOME OF WHICH IS WRAPPING INTO THE CIRCULATION
OF THE E ATLC LOW.

$$
BERG


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