[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 142342
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT 14 MAY 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
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE CROSSING THE GUIANAS ALONG 57W S OF 13N...MOVING W
15 KT. THE WAVE HAS BEEN RELOCATED FARTHER W BASED ON GREATEST
LOW-LEVEL CURVATURE AND DEEP CONVECTION BEING JUST N OF
SURINAME/GUYANA. THE CAYENNE SOUNDING ALSO INDICATED A SHALLOW
WIND SHIFT BELOW 4000 FT BETWEEN 00 AND 12Z THIS MORNING WITH
MOISTENING OF PWAT VALUES OF ABOUT 1 INCH OVER THE SAME TIME
PERIOD. BROAD SELY FLOW IS STREAMING FROM THE EQUATOR UP THE
COAST OF S AMERICA IN THE WAKE OF THE AXIS. SCATTERED MODERATE
CONVECTION IS S OF 11N BETWEEN 55W-63W WITH STRONGER TSTMS
INLAND OVER NW GUYANA...SURINAME...AND FRENCH GUIANA ALONG THE
SEA BREEZE FRONT.

CENTRAL CARIBBEAN TROPICAL WAVE ALONG 73W S OF 19N MOVING W
10-15 KT. THE WAVE IS EMBEDDED WITHIN A LARGE AREA OF
SHOWERS/TSTMS PARTLY ASSOCIATED WITH A SFC TROF LOCATED N OF
HISPANIOLA AND PUERTO RICO...AND IS APPROACHING BROAD LOW PRES
OVER THE SW CARIBBEAN. AS SUCH...ITS CURRENT POSITION IS VAGUE
AND MOVED BASED ON CONTINUITY. NUMEROUS STRONG CONVECTION IS
FORMING GENERALLY NEAR THE WAVE AXIS FROM 13N-17N BETWEEN
69W-74W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 15N12W 3N25W 2N33W 1.5N40W 4N56W
15N72W...THEN FROM 10N80W SW ACROSS COSTA RICA. ISOLATED
MODERATE CONVECTION 3N-7N BETWEEN 15W-25W. NUMEROUS
MODERATE/STRONG LOCATED OVER PANAMA AND COSTA RICA SWD INTO THE
PACIFIC. OTHER CONVECTION IS ASSOCIATED WITH TROPICAL WAVES AND
TROF OVER SW CARIBBEAN.

...DISCUSSION...

MEXICO...
WEAK N/NE LOW-LEVEL FLOW OVER SRN TX IS BEING LIFTED ALONG THE
NE SLOPES OF THE SIERRA MADRES AND INITIATED THE DEVELOPMENT OF
SCATTERED MODERATE CONVECTION FROM 23N-30N BETWEEN 98W-105W...
ALONG A LINE FROM CIUDAD VICTORIA TO ABOUT 50 NM E OF CHIHUAHUA.
AN ACTIVE SEA BREEZE FRONT OVER THE COASTAL PLAINS OF NE MEXICO
IS ALSO ENHANCING TSTMS.

GULF OF MEXICO...
A NARROW RIDGE OF HIGH PRES LIES ALONG THE N GULF COAST FROM
ABOUT JACKSONVILLE FL TO BROWNSVILLE TX WITH A COLD FRONT MOVING
IN FROM THE W OVER E TX. GENERALLY DRY AIR IN THE MID/UPPER
LEVELS IS KEEPING THE AREA MOSTLY CLEAR EXCEPT FOR THE
OCCASIONAL CIRRUS MOVING BY ALONG THE SUBTROPICAL JET. A WEAK
MID/UPPER TROF IS ACROSS THE NE GULF WATERS FROM ATLANTA GA TO
27N85W BUT IS NOT CAUSING ANY NOTICEABLE WEATHER. ELSEWHERE...
ISOLATED SHOWERS/TSTMS HAVE BEEN POPPING OVER THE N/CNTRL GULF
INTO LOUISIANA. AN EXTREMELY WEAKENED FORM OF THE TX COLD FRONT
IS EXPECTED TO FIND ITS WAY OFF THE COAST DURING THE NIGHT WITH
THE POSSIBILITY OF SHOWERS/TSTMS EXTENDING EWD TO THE FL
PANHANDLE.

CARIBBEAN...
A LOW-AMPLITUDE UPPER TROF HAS MOVED OVER THE NW CARIBBEAN WITH
AXIS FROM E CUBA SWD TO 12N78W AND IS PUMPING LARGE AMOUNTS OF
TROPICAL MOISTURE NEWD OVER THE HALF OF THE BASIN. THIS PATTERN
IS KEEPING THE DRIEST WEATHER NW OF A LINE FROM NICARAGUA TO E
CUBA. A SFC TROF IS LOCATED OVER THE SW CARIBBEAN ALONG 11N81W
16N80W WITH A POSSIBLE LOW FORMING JUST E OF SAN ANDRES ISLAND.
LOW-LEVEL CONVERGENCE IS SPARKING SCATTERED MODERATE/STRONG
CONVECTION E OF THIS FEATURE FROM 11N-16N BETWEEN 76W-80W...NOT
TO MENTION THE STRONGER CONVECTION FARTHER E ASSOCIATED WITH
TROPICAL WAVE ALONG 73W. A SECOND SFC TROF OVER THE ATLC WATERS
IS LOCATED VERY NEAR PUERTO RICO AND THE VIRGIN ISLANDS BUT MOST
OF THE CONVECTION IS N OF THESE ISLANDS. THE GFS HAS BEEN
TENDING TOWARDS DEVELOPING A LOW OVER THE SW CARIBBEAN OVER THE
NEXT 24 HRS AND THEN DRAGGING IT NEWD TOWARDS PUERTO RICO BY
TUE...BUT IT HAS BEEN RATHER DISORGANIZED AND PREMATURE SO IT
WILL BE WATCHED. NEVERTHELESS...STRONG CONVECTION IS ALREADY
OCCURRING OVER THE AREA AND MOISTURE VALUES ARE NOT EXPECTED TO
DECREASE THROUGH THE WEEK...SO THERE IS A STRONG POSSIBILITY OF
CONTINUED HEAVY FLOODING RAINS OVER PARTS OF THE GREATER
ANTILLES.

WEST/CENTRAL ATLANTIC...
A SMALL UPPER RIDGE IS BUILDING UP THE COAST OF GEORGIA AND THE
CAROLINAS WHICH IS INDUCING THE SLOW MOVEMENT OF AN UPPER TROF
LOCATED BETWEEN 67W-77W SWD TO THE TURKS AND CAICOS ISLANDS. A
COLD FRONT IS LOCATED AHEAD OF THE TROF ALONG 32N47W 29N58W
29N65W THEN STATIONARY TO 30N76W BUT IS QUICKLY WEAKENING AND
FLATTENING AS IT LOSES THE SUPPORT OF THE UPPER TROF. A REMNANT
FRONTAL TROF IS LOCATED SE OF THE FRONT ALONG 32N40W 25N50W
20N63W AND IS THE FOCUS OF MOST OF THE SHOWER/TSTM ACTIVITY
SINCE IT LIES BENEATH THE SUBTROPICAL JET. THE JET STRETCHES
FROM THE N COAST OF HISPANIOLA TO 28N52W AND IS BOUNDED ON ITS S
BY A DEEP LAYER OF MOISTURE WITH WIDESPREAD CIRRUS FROM 18N-28N.
SCATTERED SHOWERS/ISOLATED TSTMS ARE EMBEDDED WITHIN THIS CLOUD
SHIELD...ESPECIALLY N OF PUERTO RICO AS INDICATED BY SAN JUAN
RADAR.

EAST ATLANTIC...
GENERALLY WESTERLY UPPER FLOW SPANS ACROSS THE E ATLC WATERS
WITH A WEAK TROF LOCATED ALONG 33W N OF 20N. ANOTHER TROF IS
LOCATED FARTHER S IN THE TROPICS FROM ABOUT THE CAPE VERDE
ISLANDS TO 4N35W. THERE IS VERY LITTLE ACTIVE WEATHER AT THE
MOMENT AS A RIDGE OF HIGH PRES EXTENDS INTO THE AREA ALONG
32N24W 20N42W. THE SUBTROPICAL JET IS ADVECTING HIGH CLOUDS
ACROSS THE AREA FROM 22N-30N...EXTENDING ACROSS THE CANARY
ISLANDS TO NRN MOROCCO. THE LAST IMAGES OF VISIBLE IMAGERY SHOW
A LARGE DUST PLUME CONTINUING TO MOVE OFF THE W COAST OF AFRICA
FROM ABOUT THE GUINEA/SIERRA LEONE BORDER NWD TO 26N OVER
WESTERN SAHARA. SUN GLINT HAS MADE IT DIFFICULT TO DETERMINE THE
EXTENT OF THE DUST...BUT IT DOES APPEAR TO BE AT LEAST AS FAR W
AS 55W...POSSIBLY APPROACHING THE LESSER ANTILLES BEHIND THE
TROPICAL WAVE ALONG 58W.

$$
BERG


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