[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 041137
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI 04 MAR 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N8W 3N19W 2N33W 4N44W 2N52W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60/75 NM
OF THE AXIS FROM 15W-24W AND WITHIN 90 NM OF THE EQUATOR FROM
33W-38W.

...DISCUSSION...

GULF OF MEXICO...
MAIN WEATHER MAKER TODAY IS A STRONG SHORTWAVE UPPER TROUGH
MOVING ACROSS FLORIDA INTO THE W ATLC ON THE UPSLOPE SIDE OF A
MID/UPPER LEVEL TROUGH THAT COVERS THE AREA W OF 75W INCLUDING
AND MEXICO AND IS PRODUCING WIDESPREAD CLOUDINESS WITH SHOWERS/
THUNDERSTORMS OVER THE FAR E GULF...FLORIDA....AND THE BAHAMAS.
STRONG UPPER JET WITH WINDS TO 150 KT EXTENDS FROM SE TEXAS
ACROSS THE GULF OVER N FLORIDA INTO THE W ATLC IS ALSO COMING
INTO PLAY WITH ASSOCIATED DYNAMICS/LIFT BECOMING INCREASINGLY
ALIGNED WITH A 1010 MB SURFACE LOW JUST S OF KEY WEST FLORIDA.
THE LOW IS PRODUCING THE FINAL INGREDIENT WITH MOIST S FLOW TO
THE EAST AND WARM FRONT THROUGH THE FLORIDA STRAITS TO OVER THE
S BAHAMAS. ALL THIS IS SETTING THE STAGE FOR A STORMY DAY OVER
THE BAHAMAS AND RAPIDLY CLEARING OVER THE E GULF AND FLORIDA.
THE LOW AND ASSOCIATED SHOWERS/THUNDERSTORMS WILL CONTINUE TO
TRACK E THROUGH ACROSS THE BAHAMAS TODAY AND EAST OF THE AREA
THIS AFTERNOON WITH RAPID CLEARING IN ITS WAKE. ELSEWHERE...A
WEAK COLD FRONT TRAILS WSW FROM THE E GULF LOW TO THE COAST OF
MEXICO S OF VERACRUZ THEN INLAND ALONG THE E SLOPES OF THE
SIERRA MADRE MOUNTAINS. THIS COLD FRONT WILL SWEEP QUICKLY E
ACROSS INTO THE NW CARIBBEAN TODAY WITH POST-FRONTAL N FLOW AND
COLD AIR ADVECTION ACROSS THE ENTIRE AREA LATER TODAY. A SURFACE
TROUGH EXTENDS NW FROM THE SURFACE LOW INDICATING A SHARP WIND
SHIFT OVER THE CENTRAL GULF.

CARIBBEAN SEA...
LITTLE CHANGE IN THE LARGE SCALE PATTERN OVER THE CARIBBEAN WITH
BROAD MID/UPPER LEVEL RIDGING AND ANTICYCLONIC FLOW SEEN ACROSS
THE AREA E OF 35W. MID/UPPER LEVEL SUBSIDENCE CONTINUES TO
PRODUCE DRY/STABLE AIR ALOFT WITH LITTLE VERTICAL DEVELOPMENT OF
CLOUDS OR SHOWERS. IN FACT...SATELLITE IR IMAGERY SHOWS A
NOTICEABLE ABSENCE OF THE TYPICAL TRADE WIND SHOWERS. ONE AREA
OF NOTE LIES ALONG S EXTENT OF A STATIONARY FRONT OVER
HISPANIOLA TO JAMAICA WHICH IS PRODUCING BROKEN/OVERCAST
CLOUDINESS AND SCATTERED SHOWERS. THE SECOND IS OVER THE NW
CARIBBEAN AS A SURFACE TROUGH AHEAD OF THE COLD FRONT IN THE
GULF OF MEXICO EXTENDING ACROSS W CUBA TO OVER THE YUCATAN
PENINSULA NEAR BELIZE WITH A BAND OF SHOWERS/THUNDERSTORMS
TRAILING ACROSS THE AREA WITHIN 120 NM W OF THE TROUGH THAT WILL
CONTINUE TO MOVE E AS THE LOW OVER THE STRAITS OF FLORIDA TRAILS
A WEAK COLD FRONT INTO THE AREA LATER IN THE DAY. DYNAMICS/LIFT
WITH THIS SYSTEM WILL SKIRT THE AREA WITH THE STRONGEST AND MOST
NUMEROUS ACTIVITY OVER THE CARIBBEAN N OF 20N.

ATLANTIC OCEAN...
BROAD UPPER LEVEL TROUGH COVERING THE ATLC WATERS W OF 35W WITH
MOST OF THE UPPER LEVEL ENERGY N OF THE REGION RESULTING IN
ALMOST ZONAL W FLOW ACROSS THE AREA W OF 35W ALTHOUGH LINGERING
SHORTWAVES REMAIN IN THE AREA. THE SHORTWAVE MOVING ACROSS
FLORIDA INTO THE W ATLC WITH ATTENDANT SURFACE LOW/FRONT IN THE
STRAITS OF FLORIDA APPROACHING THE BAHAMAS. WIDESPREAD
CLOUDINESS AND SHOWERS/THUNDERSTORMS HAVE DEVELOPED WELL AHEAD
OF THIS SYSTEM W OF 70W WITH ONLY WIDELY SCATTERED SHOWERS
CURRENTLY REMAINING ACROSS FLORIDA. THIS SYSTEM WILL CONTINUE TO
MOVE QUICKLY E PRODUCING A LARGE SWATCH OF CLOUDINESS AND
SHOWERS/THUNDERSTORMS BETWEEN 60W-75W LATER TODAY. ASSOCIATED
COLD FRONT WILL SWEEP RAPIDLY ACROSS CUBA LATER TODAY BRINGING
DRY AIR AND A QUICK END TO SHOWER ACTIVITY FROM W TO E. A
SECOND...MUCH WEAKER...SHORTWAVE IS LOCATED OVER THE CENTRAL
ATLC WITH ATTENDANT COLD FRONT ENTERING THE AREA ALONG 32N39W TO
22N57W WHERE IT DISSIPATES AS A STATIONARY FRONT OVER HISPANIOLA
TO JAMAICA. WHILE UPPER LEVEL DYNAMICS ARE CONFINED N OF THE
AREA...LOW LEVEL MOISTURE POOLING IS PRODUCING A 120/150 NM WIDE
BAND OF SCATTERED SHOWERS ALONG THE COLD FRONT. THIS FRONTAL
BOUNDARY WILL BECOME INCREASINGLY DIFFUSE DURING THE NEXT 12 TO
24 HOURS AS A STRONGER UPSTREAM SYSTEM CONTINUES TO MOVE ACROSS
THE W ATLC INTO THE CENTRAL ATLC. THE UPSTREAM COLD FRONT NOW
EXTENDS THROUGH 32N52W SW TO 27N68W. MOISTURE POOLING FROM THE
APPROACHING SHORTWAVE OVER FLORIDA HAS DEVELOPED A 90/120 NM
WIDE BAND OF SCATTERED SHOWERS ALONG THIS COLD FRONT. OVER THE
FAR E ATLC...DEEP LAYERED LOW PRESSURE NE OF THE CANARY ISLANDS
ALONG THE COAST OF MOROCCO CONTINUES TO SLOWLY FILL AS IT MOVES
NE INTO NW AFRICA...SPAIN...AND PORTUGAL WITH A SERIES OF UPPER
LOWS ROTATE AROUND THE DEEP LAYERED LOW. ALL OF THE ASSOCIATED
SHOWER ACTIVITY REMAINS N OF THE AREA AND THE SECOND FRONT/SURGE
NOW EXTENDS FROM THE DEEP LAYERED LOW ALONG THE COAST OF AFRICA
EMERGING OFF THE COAST OF WESTERN SAHARA S OF THE CANARY ISLANDS
NEAR 26N EXTENDING SW TO 23N24W.

$$
WALLACE



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