[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011203
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT SEP 1 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURE...

THE SIXTH NAMED STORM OF THE 2007 ATLANTIC SEASON FORMS OVER THE
WINDWARD ISLANDS. AT 01/1200 UTC FELIX WAS CENTERED NEAR 12.4N
62.8W OR ABOUT ABOUT 65 NM WEST-NORTHWEST OF GRENADA MOVING
WESTWARD AT 16 KT. ON THIS TRACK...FELIX WILL MOVE AWAY FROM THE
SOUTHERN WINDWARD ISLANDS LATER THIS MORNING AND WILL BE PASSING
NEAR THE ISLANDS OF ARUBA...BONAIRE AND CURACAO LATE TONIGHT OR
EARLY SUNDAY MORNING. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004
MB. MAXIMUM SUSTAINED WINDS HAVE INCREASED AND ARE NEAR 45
MPH...WITH HIGHER GUSTS. SEE LATEST NHC INTERMEDIATE PUBLIC
ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE
FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21
KNHC FOR MORE DETAILS. RADAR IMAGERY FROM MARTINIQUE INDICATES
THAT THE CENTER HAS RECENTLY PASSED OVER GRENADA. THE CLOUD
PATTERN OF THE CYCLONE HAS IMPROVED SOMEWHAT OVERNIGHT WITH
MODERATE TO STRONG CONVECTION FROM 10N-13N BETWEEN 61W-65W AND
THE COLDEST CLOUD TOPS NOW FOCUSED ON A CLUSTER VERY NEAR THE
ESTIMATED LOW-LEVEL CENTER LOCATION.

...TROPICAL WAVES...
TROPICAL WAVE IS TILTED ALONG 18N32W 8N37W MOVING W AT ABOUT 12
KT WITH A 1010 MB LOW ALONG THE WAVE NEAR 13N. THE WAVE AND LOW
ARE EMBEDDED WITHIN A WELL ESTABLISHED MONSOON TROUGH THAT IS
PRESENT WITH WEST TO SOUTHWEST WINDS AT THE SURFACE AND 850 MB
FROM WEST AFRICA OUT TO 40W BETWEEN 5 AND 15N. MODERATE TO
ISOLATED STRONG CONVECTION IS FROM 12N-15N BETWEEN 35W-39W.

A TROPICAL WAVE IS 73W SOUTH OF 20N MOVING W 10 TO 15 KT. THE
WAVE COUPLED WITH THE COLOMBIAN LOW IS GENERATING CLUSTERS OF
SCATTERED MODERATE CONVECTION OVER WESTERN VENEZUELA AND
NORTHERN COLOMBIA...AND IS ALSO HELPING TO INDUCE ISOLATED TO
SCATTERED SHOWERS OVER HISPANIOLA AND BETWEEN E CUBA AND JAMAICA.

TROPICAL WAVE IS ALONG 82W/83W S OF 22N MOVING W 10 TO 15 KT.
THE WAVE IS ENHANCING SOME SHOWER ACTIVITY OVER THE ISLE OF
YOUTH CUBA AND OVER THE SW CARIBBEAN AND THE CARIBBEAN PLAINS OF
NICARAGUA.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N16W 13N33W 10N40W 9N5W 12N58W.
IN ADDITION TO SHOWERS/CONVECTION ASSOCIATED WITH THE TROPICAL
WAVE...CLUSTERS OF SCATTERED MODERATE CONVECTION ARE ALONG THE
COAST OF SW AFRICA FROM 8-13N EAST OF 24W. WIDELY SCATTERED
SHOWERS ARE FROM 5N-10N WEST OF 44W.

DISCUSSION...
GULF OF MEXICO...
WEAK PRESSURE GRADIENT DOMINATES THE AREA WITH MAINLY LIGHT AND
VARIABLE WINDS. A WEAK SURFACE TROUGH CONTINUES OVER THE SW GULF
VERY CLOSE THE MEXICAN COAST ALONG 24N97W 20N95W AND 18N94W.
CONVECTION HAS SLIGHTLY INCREASE OVERNIGHT...MAINLY ON THE
NORTHERN END OF THE TROUGH WITH A CLUSTER OF SCATTERED MODERATE
CONVECTION WITHIN 35 NM OF 22N97W. A WEAK 1011 MB LOW IS
CENTERED OVER N FLORIDA NEAR 30N84W. A SURFACE TROUGH EXTENDS SW
FROM THE LOW TO 26N90W. ISOLATED SHOWERS AMD TSTMS ARE RELATED
TO THE TROUGH/LOW OVER THE NE CORNER OF THE GULF AND NORTHERN
FLORIDA...JUST NORTH OF TAMPA BAY. SIMILAR CONVECTION IS ALSO
FOUND OVER THE NW GULF WITH A MOIST ONSHORE FLOW. A WEAK HIGH
PRESSURE CENTER OF 1014 MB IS AT 28N92W. ALOFT...A RIDGE IS OVER
MEXICO AND THE W GULF W OF 93W. A TROUGH IS OVER THE CENTRAL
GULF 88W-93W.  AN UPPER LEVEL RIDGE DOMINATES FLORIDA AND THE
EASTERN GULF TO 88W. EXPECT CONVECTION OVER MOST OF THE GULF
ESPECIALLY OVER THE W PORTION...AND OVER THE NE GULF AND
FLORIDA...DURING THE NEXT 24 HOURS.

CARIBBEAN SEA...
ATTENTION REMAINS FOCUSED ON TROPICAL STORM FELIX MOVING ACROSS
THE SOUTHERN WINDWARD ISLANDS. FELIX IS EXPECTED TO PRODUCE
ADDITIONAL RAINFALL ACCUMULATIONS OF 1 TO 2 INCHES ACROSS THE
WINDWARD ISLANDS WITH STORM TOTAL AMOUNTS OF 7 INCHES POSSIBLE.
RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE OVER COASTAL
VENEZUELA AND THE NETHERLANDS ANTILLES ISLANDS OF ARUBA...
BONAIRE AND CURACAO. A PAIR OF TROPICAL WAVES ARE MOVING WWD
ACROSS THE BASIN. SEE ABOVE. TRADEWINDS ARE MOSTLY 10-15 KT. IN
THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER CENTRAL AMERICA
W OF 85W.  AN UPPER LEVEL LOW IS OVER THE SW CARIBBEAN NEAR
12N81W. A WEAK RIDGE ANCHORED ON A HIGH OVER THE NE CARIBBEAN
COVERS THE REMAINDER OF THE AREA. EXPECT THE HIGHEST POTENTIAL
FOR CONVECTION TO BE NEAR TROPICAL STORM FELIX AND THE TROPICAL
WAVES DURING THE NEXT 24 HOURS.

ATLANTIC OCEAN...
AS OF 06Z...A SURFACE TROUGH ENTERS THE AREA NEAR 31N70W THEN
CONTINUES MAINLY WEST TO 29N77W. SCATTERED MODERATE TO ISOLATED
STRONG CONVECTION IS E OF THE TROUGH AXIS N OF 28W BETWEEN
60W-70W. A DISSIPATING STATIONARY FRONT CLIPS THE CENTRAL
ATLANTIC ALONG 30N BETWEEN 43W-50W WITH A NARROW LINE OF
SHOWERS. A SURFACE RIDGE DOMINATES MOST OF THE FORECAST AREA
WEST OF 70W WITH MODERATE TRADE WINDS. ALOFT...AN UPPER LEVEL
HIGH IS CENTERED OVER THE WESTERN ATLANTIC NEAR 27N67W. AN UPPER
TROUGH OVER THE CENTRAL ATLC N OF AREA SUPPORTS THE ABOVE
MENTIONED STATIONARY FRONT. AN UPPER LEVEL RIDGE COVERS THE
CENTRAL-EASTERN ATLANTIC E OF 45W ANCHORED ON A HIGH NEAR
22N30W.

$$
GR


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