[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111746
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1645 UTC.

...TROPICAL WAVES...
E ATLC TROPICAL WAVE IS ALONG 32W S OF 12N MOVING W 10-15 KT.
POSITION IS BASED ON TURNING IN THE LOW CLOUD FIELD... LONG-
TERM SATELLITE LOOPS AND A GENERAL NORTHWARD BEND IN THE ITCZ IN
THE AREA.  SCATTERED MODERATE CONVECTION IS FROM 4N-6.5N BETWEEN
25W-33W.

TROPICAL WAVE IS NEAR FRENCH GUIANA ALONG 52W S OF 16N MOVING W
15 KT.  THE CAYENNE SOUNDING SHOWED A WIND SHIFT FROM NE TO E
WINDS IN THE MID-LEVELS ALONG WITH A SIGNIFICANT INCREASE IN
DEEP-LAYERED MOISTURE.  THE WAVE SHOULD BRING AN ENHANCED CHANCE
OF RAIN TODAY IN NE SOUTH AMERICA...SPREADING INTO THE LEEWARD
ISLANDS BY LATE TOMORROW AND MOSTLY AFFECTING THE E CARIBBEAN S
OF MARTINIQUE WITH ENHANCED RAIN/POSSIBLE TSTMS.  ISOLATED
SHOWERS/TSTMS IS BETWEEN 4N-9N FROM 50W-55W.

CENTRAL AMERICAN TROPICAL WAVE IS ALONG 91W S OF 17N MOVING W
10-15 KT. ASSOCIATED DEEP CONVECTION IS IN THE EPAC AREA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N14W 5N22W 5N32W 3N29W 7N52W
5N57W.  ISOLATED MODERATE CONVECTION WITHIN 120 NM OF AXIS W OF
46W AND E OF 20W.  WIDELY SCATTERED MODERATE FROM 1.5N-6N
BETWEEN 27W-35W.

...DISCUSSION...

GULF OF MEXICO INTO THE W ATLANTIC...
WEAK 1016 MB LOW IS SITTING ABOUT 100 NM E OF SAVANNAH GEORGIA
WITH A TROUGH EXTENDING SSW ACROSS CENTRAL FLORIDA NEAR CAPE
CANAVERAL.  THE SYSTEM HAS A STACKED STRUCTURE WITH A MID/UPPER
LOW PRESENT IN VIRTUALLY THE SAME PLACE.  COOLER TEMPERATURES
ALOFT ASSOCIATED WITH THE LOW ARE ALLOWING ISOLATED TSTMS TO
FORM WITHIN 120 NM OF THE LOW.  A BIT MORE CONVECTION IS
POSSIBLE TODAY OVER FLORIDA N OF LAKE OKEECHOBEE ALONG THE
SEA-BREEZES AS LOW/MID-LEVEL MOISTURE HAS INCREASED SINCE
YESTERDAY WITH A BIT MORE UNSTABLE ATMOSPHERE.  HOWEVER DRY
CONDITIONS ARE EXPECTED S OF 27N WITH DRY NW FLOW AND SUBSIDENCE
ALOFT PREVENTING SIGNIFICANT DEEP CONVECTION.  TYPICAL
SPRINGTIME SMOKE EXTENDS FROM FIRES OVER S MEXICO ACROSS THE BAY
OF CAMPECHE AND THE W GULF THOUGH THE VISIBILITY RESTRICTION
APPEARS TO NOT BE AS SEVERE AS LAST WEEK.

CARIBBEAN...
DISTURBED WEATHER CONTINUES IN THE SW CARIBBEAN COURTESY OF THE
NEARBY ITCZ AND A MID/UPPER JET PROVIDING DIVERGENCE ALOFT.
SCATTERED TSTMS ARE S OF SAN ANDRES W OF 79W.  CONTINUED PERIODS
OF TSTMS ARE LIKELY FOR THE NEXT FEW DAYS WITH LOTS OF DEEP-
LAYERED MOISTURE AND UPPER ENERGY.  FARTHER NE.... UNSETTLED
WEATHER ALSO REMAINS FOR THE CENTRAL AND E CARIBBEAN N OF 17N E
OF CUBA ASSOCIATED WITH THE REMNANTS OF A FRONT.  ANOTHER ACTIVE
TSTM DAY IS LIKELY FOR HISPANIOLA WITH PLENTY OF MOISTURE...
WHICH COULD CAUSE FLASH FLOODS AND MUDSLIDES IN HIGHER TERRAIN.
THIS WEATHER PATTERN SHOULD REMAIN ABOUT THE SAME FOR THE NEXT
FEW DAYS SO THE THREAT OF HEAVY RAINS/FLASH FLOODING WILL
CONTINUE IN THE AREA.  FARTHER E... ONE MORE NICE DAY IN THE SE
CARIBBEAN BEFORE A TROPICAL WAVE ENTERS TOMORROW.  MOSTLY ZONAL
UPPER WINDS DOMINATE THE AREA BUT SHOULD CHANGE A BIT AS AN
UPPER TROF IN THE W ATLC DROPS THRU THE CENTRAL CARIBBEAN DURING
THE NEXT FEW DAYS.

REST OF THE ATLANTIC...
POWERFUL MID-LATITUDE LOW IS SPINNING NEAR 38N56W WITH
ASSOCIATED MID/UPPER TROUGH DROPPING S INTO THE AREA TO 26N56W.
A WEAKENING COLD FRONT ENTERS THE AREA NEAR 31N51W BECOMING
STATIONARY TO 22N57W THEN 20N56W AND DISSIPATING.  DIVERGENCE
FROM THE UPPER TROUGH IS ENHANCING WIDELY SCATTERED TSTMS N OF
26N WITHIN 90 NM E OF THE FRONT WITH OTHER ISOLATED SHOWERS
WITHIN 75 NM OF THE FRONT S OF 26N.  DEEP LAYERED RIDGING
DOMINATES THE ATLC FROM 30W-45W WITH HIGH CLOUDS POURING ACROSS
THE RIDGE N OF 20N.  SURFACE RIDGING NOSES INTO THE AREA ALONG
31N37W TO 21N51W AND SE ALONG 31N31W TO 26N22W NE TO THE CANARY
ISLANDS.  MID/UPPER LEVEL TROUGH EXTENDS FROM THE CANARY ISLANDS
SW TO THE CAPE VERDE ISLANDS WITH LITTLE IN THE WAY OF CLOUDS OR
CONVECTION.  MOST OF THE DEEP TROPICS HAVE MODERATE/STRONG
SUBSIDENCE ALOFT... PROBABLY DUE TO CONVERGENCE BETWEEN A
MID/UPPER HIGH NEAR 8N58W AND AN UPPER TROUGH FROM THE CAPE
VERDES TO 7N38W.  ITCZ CONVECTION IS ENHANCED TODAY DUE TO THIS
TROUGH.

$$
BLAKE

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