[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 230550
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT JUL 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...SPECIAL FEATURES...

TROPICAL STORM FRANKLIN IS CENTERED NEAR 28.7N 76.1W...OR
ABOUT 140 NM NNE OF GREAT ABACO ISLAND IN THE NORTHERN
BAHAMAS...AT 22/0600 UTC MOVING N 8 KT. MAXIMUM SUSTAINED WIND
SPEED IS 45 KT WITH GUSTS TO 55 KT.  ESTIMATED MINIMUM CENTRAL
PRESSURE IS 1001 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.
FRANKLIN REMAINS A SMALL AND CONNECTIVELY DISORGANIZED
SYSTEM....THE CONVECTIVE BANDS ARE PRIMARILY LOCATED OVER THE
ERN SEMICIRCLE. SCATTERED MODERATE CONVECTION IS FROM 26N-29N
BETWEEN 74W-77W.  ONLY BROKEN LOW/MID LEVEL CLOUDS CONTINUE TO
EXTEND SW ACROSS THE CNTRL BAHAMAS FROM ELEUTHERA SE TO LONG
ISLAND.

A STRONG TROPICAL WAVE IS LOCATED OVER THE CNTRL GULF OF MEXICO
SWD ALONG THE YUCATAN COAST ALONG 88W MOVING W 10-15 KT. THE
CONVECTIVE CLOUD PATTERN HAS GAINED CONSIDERABLE CURVATURE
THROUGH THE EVENING AND SFC A 1011 MB LOW HAS FORMED ALONG THE
WAVE AXIS NEAR 19N89W. SCATTERED MODERATE/STRONG CONVECTION
EXTENDS OVER THE YUCATAN CHANNEL...NE YUCATAN...AND S/CNTRL GULF
OF MEXICO FROM 13N-24N BETWEEN 83W-93W AND THEN STRETCHES S/SE
OVER THE GULF OF HONDURAS TO NE HONDURAS. A LARGE UPPER LEVEL
HIGH IS CENTERED ADJACENT TO THIS SYSTEM NEAR THE W TIP OF CUBA
AND IS PROVIDING A FAVORABLE ENVIRONMENT FOR CONTINUED
CONVECTIVE DEVELOPMENT OVER THIS AREA TODAY. THE LOW IS EXPECTED
TO RE-EMERGE OVER THE SE BAY OF CAMPECHE LATER TODAY AT WHICH
POINT TROPICAL CYCLONE DEVELOPMENT WILL BE POSSIBLE...IN THE
NEXT 24-36 HRS.

...TROPICAL WAVES...

EAST ATLANTIC TROPICAL WAVE ALONG 37W/38W S OF 25N MOVING W
20-25 KT.  THE SIGNATURE REMAINS QUITE AMPLIFIED WITH WIDESPREAD
DUST EXTENDING PRIMARILY W OF 30W TO THE LESSER ANTILLES. THE
ATMOSPHERE REMAINS EXTREMELY DRY WITH SOME MOISTURE ON THE BACK
SIDE OF THE WAVE WHICH HAS BEEN PULLED AROUND THE N AND W SIDE
OF THE CIRCULATION...ALL DEEP CONVECTION IS UP TO 600 NM E OF
THE WAVE ALONG THE ITCZ.

EAST CARIBBEAN TROPICAL WAVE ALONG 62W/63W S OF 21N MOVING W
20-25 KT. THE INVERTED-V SIGNATURE IS LESS DISTINCT OVER THE
LAST FEW DAYS...AND APPEARS TO BE TILTED SW TO NE FROM ISLA DE
MARGARITA TO ANTIGUA/BARBUDA.  SCATTERED MODERATE CONVECTION
MAINLY OVER VENEZUELA S OF 11N BETWEEN 63W-67W...ISOLATED
SHOWERS/TSTMS FROM 13N-19N BETWEEN 59W-65W.

WEAK TROPICAL WAVE ALONG CENTRAL COLOMBIA NEAR 74W/75W S OF 13N
MOVING W 10-15 KT. ONLY SCATTERED MODERATE/ISOLATED STRONG
CONVECTION MOVING OVER SOUTHERN PANAMA INTO THE PACIFIC.

SEE SPECIAL FEATURES FOR DISCUSSION ON TROPICAL WAVE NEAR
YUCATAN PENINSULA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 22N8W 11N16W 16N28W 14N33W 9N40W
5N50W 4N55W. SCATTERED MODERATE/STRONG CONVECTION CONTINUES TO
MOVE OFF THE COAST OF AFRICA...POSSIBLY ASSOCIATED WITH A NEW
TRPCL WAVE...FROM 6N-13N BETWEEN 15W-23W. SCATTERED MODERATE
FROM 7N-12N BETWEEN 27W-34W.

...DISCUSSION...

GULF OF MEXICO...
SCATTERED SHOWERS/TSTMS CONTINUE TO INCREASE IN COVERAGE FROM
THE SE GULF INTO THE ERN BAY OF CAMPECHE AS AN AMPLIFIED TRPCL
WAVE AND LOW PUSHES ACROSS THE YUCATAN PENINSULA. A MID/UPPER
LOW CENTERED NEAR 21N99W CONTINUES TO MOVE TO THE W INTO CNTRL
MEXICO AS THE UPPER LOW CURRENTLY LOCATED NEAR 21N85W SLOWLY
PUSHES W AND BEGINS TO REPLACE IT.  DEEP SLY FLOW BETWEEN THESE
TWO FEATURES IS PULLING MOISTURE NWD OVER SE MEXICO WITH BANDS
OF CONVECTION MOVING ONSHORE THE MAYAN COAST. THE LOW ASSOCIATED
WITH THE TRPCL WAVE LOCATED NEAR 18N89W IS EXPECTED TO RE-EMERGE
OVER THE SRN BAY OF CAMPECHE LATER TODAY WITH THE POSSIBILITY OF
TROPICAL CYCLONE DEVELOPMENT OVER THE WEEKEND. SEE SPECIAL
FEATURES FOR FURTHER DISCUSSION. ELSEWHERE...A PATCH OF
SUBSIDENCE/DRY AIR OVER THE E GULF FROM 27N-30N BETWEEN FLORIDA
AND TEXAS WILL CONTINUE THROUGH THE REST OF THE WEEKEND AND THEN
SPREAD ACROSS THE REST OF THE GULF FOR MUCH OF NEXT WEEK.

CARIBBEAN...
A LARGE SWATH OF SUBSIDENCE/DRY AIR IN THE MID/UPPER LEVELS
CONTINUES TO TRAVERSE ACROSS THE AREA FROM E TO W WHICH IS
KEEPING MOST OF THE SHOWER/TSTM ACTIVITY W OF 83W. A FEW SHOWERS
ARE LOCATED OVER THE E CARIBBEAN ALONG A TRPCL WAVE. HAZY SKIES
WILL CONTINUE TO MOVE ACROSS THE LEEWARD ISLANDS INTO THE E
CARIBBEAN IN THE WAKE OF THE TRPCL WAVE...AND SHOULD LAST FOR
SEVERAL DAYS CONSIDERING THE DUST LOCATED UPSTREAM.
ELSEWHERE...SEE SPECIAL FEATURES FOR DISCUSSION ON TRPCL WAVE
AND CONVECTION OVER THE NW CARIBBEAN. WIND SPEED CONVERGENCE
OVER THE SW CARIBBEAN IS INITIATING WIDELY SCATTERED MODERATE
CONVECTION FROM 9N-14N BETWEEN COLOMBIA AND NICARAGUA.

WEST ATLANTIC...
TROPICAL STORM FRANKLIN IS MOVING N AWAY FROM THE NRN BAHAMAS
LIFTED BY A SHARP UPPER TROF LOCATED OVER FLORIDA. A LARGE UPPER
TROF IS CENTERED JUST N OF PUERTO RICO NEAR 29N67W AND IS MOVING
SLOWLY TO THE W...EMBEDDED WITHIN A MUCH LONGER MID-OCEANIC TROF
THAT EXTENDS NE TO 26N54W. A LARGE AREA OF DRY AIR IS
CIRCULATING WITHIN THE LOW S OF 24N E OF 74W BUT WIDELY
SCATTERED SHOWERS/TSTMS ARE LOCATED N OF 30N BETWEEN 57W-64W DUE
TO A SHARP SHORTWAVE TROF N OF THE AREA.

CENTRAL/EAST ATLANTIC...
THE DUST HAS JUST ABOUT SPREAD OVER THE ENTIRE EAST AND CNTRL
ATLC...LOCATED S AND E OF A LINE FROM ANTIGUA/BARBUDA NE TO
26N51W 33N31W. AN UPPER LEVEL HIGH IS CENTERED NEAR 21N37W WITH
A RIDGE EXTENDING SW TO 10N57W. THE SUBTROPICAL RIDGE IS
WELL-ESTABLISHED ALONG 28N AND EXTENDS NE TO A 1027 MB HIGH NEAR
THE AZORES. A SECOND UPPER HIGH IS ALSO LOCATED JUST SW OF THE
CANARY ISLANDS NEAR 25N22W...AND A SMALL UPPER LOW IS DROPPING
SW TOWARDS THE MOROCCAN COAST NEAR 33N10W. THE BACK SIDE OF THE
DUST PLUME APPEARS TO BE LOCATED ROUGHLY ALONG 30W WITH ANOTHER
STATIONARY MASS OF DUST TRAPPED BETWEEN THE CAPE VERDE AND
CANARY ISLANDS.

$$
JP/DS



This weather bulletin was brought to you by:
www.nashvilleweather.net