[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291734
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN MAY 29 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...

EAST ATLANTIC TROPICAL WAVE ALONG 36W S OF 14N MOVING W 15 KT.
THE WAVE IS LOCATED BENEATH A SHARP MID/UPPER LEVEL TROF WHICH
IS PROVIDING STRONG WESTERLY SHEAR. THE ITCZ IS EXCEPTIONALLY
LINEAR ACROSS THE WAVE AXIS BUT A WEAK CIRCULATION IS NOTED IN
THE MORE STABLE AIR MASS TO THE N NEAR 11N. NO SIGNIFICANT
CONVECTION.

TROPICAL WAVE CROSSING THE LESSER ANTILLES ALONG 61W/62W S OF
20N MOVING W 20-25 KT. THE CIRCULATION ASSOCIATED WITH THE WAVE
HAS BECOME A LITTLE LESS DISTINCT DURING THE PAST 24 HRS BUT
THERE IS STILL PLENTY OF DEEP CONVECTION. SCATTERED MODERATE
CONVECTION IS SPREADING FROM E TO W OVER THE SRN WINDWARD
ISLANDS AND NE VENEZUELA FROM 9N-12N BETWEEN 58W-63W...
PARTICULARLY OVER TRINIDAD AND TOBAGO. ONLY ISOLATED SHOWERS ARE
STREAMING ACROSS THE REST OF THE ISLAND CHAIN TO THE N.

W CARIBBEAN TROPICAL WAVE ALONG 78W S OF 18N MOVING W 10-15 KT.
A 5-DAY LOOP OF SATELLITE IMAGERY SHOWS THE WAVE LOSING MOST OF
ITS ENERGY AS IT CROSSES THE CARIBBEAN BASIN BUT A WEAK FEATURE
CAN STILL BE TRACKED TO NEAR JAMAICA. THE WAVE WAS LOCATED ALONG
THE LEADING EDGE OF THE FIRST AFRICAN DUST SURGE...AND NOW THIS
DRY AIR MASS HAS SPREAD ACROSS THE W CARIBBEAN LOWERING PWAT
VALUES BELOW 1.00" S OF JAMAICA. AS SUCH...DEEP CONVECTION...AND
EVEN CLOUDINESS...ARE HARD TO COME BY.

CENTRAL AMERICA TROPICAL WAVE ALONG 89W S OF 16N MOVING W 10 KT.
A MESOSCALE CONVECTIVE COMPLEX HAS BEEN MOVING NWWD ALONG THE
WAVE FROM PANAMA TO EL SALVADOR DURING THE PAST 36 HRS...BUT
THIS CLUSTER HAS SINCE DISSIPATED. WIDELY SCATTERED MODERATE
CONVECTION IS E OF THE WAVE AXIS OVER SRN NICARAGUA AND THE
COASTAL WATERS OFF COSTA RICA DNA W PANAMA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 13N10W 8N35W 9N46W 8N55W 11N62W.
WIDELY SCATTERED MODERATE CONVECTION WITHIN 175 NM OF THE AXIS
BETWEEN 15W-20W...AND FROM 3N-8N BETWEEN 10W-20W. ISOLATED
SHOWERS/TSTMS WITHIN 45 NM OF THE AXIS BETWEEN 24W-37W. WIDELY
SCATTERED MODERATE 150 NM S OF THE AXIS BETWEEN 52W-60W
INCLUDING NEAR THE COASTS OF GUYANA AND SURINAME.

...DISCUSSION...

MEXICO AND GULF OF MEXICO...
A PAIR OF MID/UPPER LEVEL LOWS ARE MOVING EWD ACROSS THE RIO
GRANDE VALLEY WITH THE MOST VIGOROUS OF THE TWO HAVING CROSSED
THE RIVER FROM MEXICO INTO SE TEXAS. THE SUBTROPICAL JET IS
TUCKED BENEATH THESE LOWS RANGING FROM CNTRL MEXICO EWD THRU THE
MIDDLE OF THE GULF OF MEXICO TO CNTRL FLORIDA...AROUND A
SMALL-SCALE RIDGE WHICH IS POKING N FROM THE YUCATAN PENINSULA.
THE JET CONTINUES TO ADVECT DRY AIR OVER MOST OF CNTRL MEXICO
ALTHOUGH MOISTURE IS INCREASING OVER THE GULF AS HIGH CIRRUS
MOVE IN FROM THE S. A SHORTWAVE TROF ROTATING AROUND THE PAIR OF
UPPER LOWS IS CURRENTLY SWINGING ACROSS THE NW GULF AS IS
TRIGGERING A CLUSTER OF TSTMS OVER LOUISIANA...BUT ONLY A FEW
STRAGGLER CELLS EXTENDS S OVER THE COASTAL WATERS. ELSEWHERE...
THE REST OF THE GULF IS UNDER MAINLY FAIR SKIES. THROUGH THE
REST OF THIS WEEK...THE UPPER LOWS ARE EXPECTED TO DROP SE AND
BECOME A STATIONARY TROF OVER THE W GULF BY TUE...SETTING UP FOR
A FAIRLY WET PATTERN OVER THE CNTRL GULF AND N/CNTRL GULF COAST.

CARIBBEAN...
THE WEATHER ACROSS THE CARIBBEAN REMAINS OVERWHELMINGLY DRY FOR
ANOTHER DAY...WITH THE EXCEPTION OF A FEW SHOWERS/TSTMS AROUND
ITS PERIPHERY. A TRPCL WAVE IS MOVING ACROSS THE LESSER
ANTILLES...AS DESCRIBED ABOVE...WITH WIDELY SCATTERED MODERATE
CONVECTION SPREADING ACROSS THE SRN WINDWARD ISLANDS AND NE
VENEZUELA. ISOLATED SHOWERS/TSTMS ARE ALSO POPPING OVER THE E
CARIBBEAN FROM 12N-18N E OF 70W AS THE EASTERLY FLOW DEEPENS.
FARTHER TO THE W...THE USUAL LOW-LEVEL CONVERGENCE OF WINDS OVER
THE SW CARIBBEAN IS PRODUCING SCATTERED TSTMS OFF THE COASTS OF
W PANAMA AND COSTA RICA...WHICH ARE MOVING W ONSHORE.
OTHERWISE...A LARGE UPPER LEVEL ANTICYCLONE OVER WRN HONDURAS IS
PULLING DRY AIR SWD OVER THE E/CNTRL CARIBBEAN...SUPPRESSING
DEEP CONVECTION OVER THE AREA.

ATLANTIC...
A WEAK COLD FRONT IS DROPPING S OFF THE SE U.S. COAST AND JUST
BRUSHES THE FAR W ATLC WATERS. THE LOW-LEVEL FLOW AHEAD OF THE
FRONT OVER FLORIDA IS GENERALLY WESTERLY...AND THIS IS
CONVERGING WITH FLOW ASSOCIATED WITH THE SUBTROPICAL RIDGE OVER
THE ATLC TO PRODUCE A CONVERGENCE LINE THAT RUNS FROM BIMINI NE
ACROSS GREAT ABACO TO 29N76W. SCATTERED SHOWERS/TSTMS HAVE BEEN
WITHIN 45 NM OF THIS LINE...PRIMARILY N OF THE BAHAMAS. A
PROGRESSIVE SHORTWAVE TROF IS MOVING EWD ACROSS THE W ATLC ALONG
72W AND IS ASSOCIATED WITH A SUBSIDENT CIRCULATION WHICH IS
SUPPRESSING CLOUD COVER. HOWEVER...DIFFLUENCE IS INCREASING E OF
THE TROF AND IS SUPPORTING THE DEVELOPMENT OF ISOLATED
SHOWERS/TSTMS FROM 22N-26N BETWEEN 61W-68W ALONG WHAT LOOKS TO
BE A DETACHED SEGMENT FROM THE E CARIBBEAN TRPCL WAVE. FARTHER
E...ANOTHER UPPER TROF EXTENDS ALONG 32N42W 20N50W AND IS
COLLOCATED WITH A 1017 MB SFC LOW WHICH IS SPLITTING THE
SUBTROPICAL RIDGE NEAR 30N47W. A STATIONARY CUT-OFF UPPER LOW IS
CENTERED OVER THE TROPICS NEAR 13N36W WITH THE SUBTROPICAL JET
JUMPING TO THE N AND E PAST THE CAPE VERDE ISLANDS. HIGH LEVEL
MOISTURE IS STREAMING ALONG THE JET BUT TURNS QUICKLY EWD INTO W
AFRICA AS IT ENCOUNTERS THE SRN FLANK OF A SECOND UPPER LOW
MOVING INLAND OVER MOROCCO. THE PLUME OF AFRICAN DUST EXTENDS
ACROSS THE ENTIRE ATLC GENERALLY BETWEEN THE ITCZ AND
20N...BECOMING MORE DIFFUSE AS IT ENTERS THE CARIBBEAN BASIN.
LOW DRIFTING SAND IS BEING REPORTED ALONG THE COAST OF
MAURITANIA WHERE THE PLUME IS EMERGING WITH VISIBILITIES DOWN TO
3 MILES.

$$
BERG


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