[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 182329
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU OCT 18 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE
AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION
IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 45W S OF 17N MOVING W 10-15 KT.  VISIBLE
IMAGERY SHOWS A FAINT INVERTED V-SHAPE IN THE LOW-LEVEL CLOUD
FIELD.  CONVECTION HAS LESSENED SINCE YESTERDAY AND IS NOW E OF
THE WAVE AXIS AND CONFINED TO THE ITCZ AXIS.  WIDELY SCATTERED
MODERATE CONVECTION IS FROM 6N-11N BETWEEN 40W-44W.

WEAK TROPICAL WAVE IS IN THE E CENTRAL CARIBBEAN ALONG 68W S OF
17N MOVING W 10-15 KT. THIS WAVE HAS BEEN CHALLENGING TO TRACK
OVER THE PAST COUPLE OF DAYS. A LONG-TERM SATELLITE LOOP AND
SOUNDING DATA POSSIBLY SUGGESTS THAT THIS WAVE PASSED BARBADOS A
DAY OR TWO AGO. THERE IS VERY LITTLE EVIDENCE OF THIS WAVE ON
TODAY'S IMAGERY OR IN THE OTHER AVAILABLE DATA...SO MAINTAINED
FORWARD CONTINUITY.  NO SIGNIFICANT CONVECTION IS NOTED.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 10N12W 8N20W 9N30W 8N50W 10N60W.  IN
ADDITION TO THE CONVECTION MENTIONED IN THE TROPICAL WAVE
SECTION...SCATTERED MODERATE TO STRONG CONVECTION IS INLAND OVER
W AFRICA FROM 10N-13N BETWEEN 10W-15W.  ISOLATED MODERATE
CONVECTION IS FROM 4N-12N BETWEEN 33W-40W.  SCATTERED MODERATE
CONVECTION IS FROM 8N-13N BETWEEN 48W-60W.

DISCUSSION...

GULF OF MEXICO...
THE GULF HAS 10-15 KT SOUTHERLY WINDS WITH MOSTLY FAIR WEATHER.
A PREFRONTAL TROUGH OVER THE FLORIDA PANHANDLE IS PRODUCING
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 29N-32N
BETWEEN 83W-90W AND IS MOVING E.  IN THE UPPER LEVELS...AN UPPER
LEVEL HIGH IS CENTERED OVER THE NE GULF NEAR 30N85W.  A RIDGE
AXIS EXTENDS NE TO NEW JERSEY.  UPPER LEVEL MOISTURE COVERS THE
NE GULF N OF 28N AND E OF 90W.  STRONG SUBSIDENCE IS OVER THE
REMAINDER OF THE GULF.  EXPECT...CONTINUED CONVECTION OVER THE E
GULF AND FLORIDA DURING THE NEXT 24 HOURS.

CARIBBEAN SEA...
A TROPICAL WAVE IS OVER THE E CARIBBEAN.  SEE ABOVE.  IN
ADDITION... SELY SURFACE FLOW AND SLY UPPER LEVEL FLOW OVER CUBA
IS PRODUCING ISOLATED MODERATE CONVECTION OVER THE HIGHER
ELEVATIONS OF CUBA BETWEEN 71W-84W.  MODERATE TRADEWINDS
DOMINATE THE REMAINDER OF THE CARIBBEAN.  A 1008 MB LOW IS
CENTERED OVER N COLOMBIA NEAR 11N72W.  A SURFACE TROUGH EXTENDS
NW FROM THE LOW TO THE CAYMAN ISLANDS ALONG 12N79W 19N92W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE
CENTRAL GULF FROM 10N-18N BETWEEN 74W-81W.  IN THE UPPER
LEVELS... AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN
NEAR 20N86W MOVING W.  UPPER LEVEL DIFFLUENCE E OF THE CENTER IS
HELPING TO PRODUCE THEE CONVECTION OVER THE CENTRAL CARIBBEAN.
EXPECT... THE TROPICAL WAVE TO PRODUCE SHOWERS OVER THE CENTRAL
CARIBBEAN OVER THE NEXT 24 HOURS.  ALSO EXPECT THE CONVECTION
OVER THE CENTRAL CARIBBEAN TO MOVE W.

ATLANTIC OCEAN...
A COLD FRONT IS OVER THE CENTRAL ATLANTIC ALONG 32N33W 26N45W.
A DISSIPATING STATIONARY FRONT CONTINUES W TO THE W ATLANTIC
ALONG 25N55W 27N67W.  SCATTERED SHOWERS ARE WITHIN 60 NM OF THE
FRONTS.  IN ADDITION...WIDELY SCATTERED MODERATE CONVECTION IS
FROM 22N-24N BETWEEN 54W-62W.  A 1020 MB HIGH IS OVER THE E
ATLANTIC NEAR 26N27W PRODUCING MAINLY LIGHT WINDS.  MODERATE
TRADES PERSIST IN THE TROPICS.  IN THE UPPER LEVELS...AN UPPER
LEVEL RIDGE IS OVER THE W ATLANTIC N OF 20N AND W OF 65W.  THE
BASE OF AN UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC N OF
20N BETWEEN 40W-65W.  A RIDGE IS OVER THE E ATLANTIC N OF 20N
AND E OF 40W.  A SMALL UPPER LEVEL LOW IS OVER THE TROPICAL
ATLANTIC OFF THE COAST OF S AMERICA NEAR 7N51W.  FURTHER E...AN
UPPER LEVEL HIGH IS OVER THE TROPICAL E ATLANTIC NEAR 10N30W.
UPPER LEVEL WINDS ARE THUS UNFAVORABLE NEAR THE CAPE VERDE
ISLANDS FOR TROPICAL CYCLONE FORMATION.

$$
FORMOSA


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