[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141756
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU JUN 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS LOCATED ALONG 25W MOVING W NEAR 15 KT. WEAK
TURNING IS NOTED IN THE ITCZ ALONG THE WAVE AXIS. SCATTERED
MODERATE CONVECTION WITHIN 120 NM EITHER SIDE OF THE AXIS FROM
6N-9N.

A LOW AMPLITUDE TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES
WITH THE AXIS ALONG 60W. IT IS MOVING QUICKLY TO THE W NEAR 25
KT. MOST OF THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE WAVE IS
WITHIN ITCZ. THE WAVE IS GENERATING SOME SHOWERS AND ISOLATED
TSTMS OVER TRINIDAD AND TOBAGO.

A LOW AMPLITUDE TROPICAL WAVE IS OVER WESTERN VENEZUELA NEAR 70W
SOUTH OF 13N MOVING W NEAR 15 KT. POSITION IS BASED ON SATELLITE
IMAGERY AND SFC OBSERVATIONS FROM THE ABC ISLANDS. SHOWER AND
TSTM ACTIVITY RELATED TO THE WAVE HAS SLIGHTLY DIMINISHED IN THE
LAST FEW HOURS AND IS AFFECTING THE AREA OF LAKE MARACAIBO. A
SURGE IN THE TRADE WINDS FOLLOWS THIS TROPICAL WAVE. WINDS IN
THE 20 TO 25 KT RANGE ARE BLOWING ACROSS THE CENTRAL CARIBBEAN
AND IS EXPECTED TO INCREASE A BIT FRI. AN EARLIER QUIKSCAT PASS
CONFIRMED THESE MODERATE TO STRONG WINDS.

A TROPICAL WAVE IS MOVING ACROSS GUATEMALA AND THE EPAC WITH
THE AXIS ALONG 89W/90W. NO DEEP CONVECTION IS ASSOCIATED WITH
THIS FEATURE.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N16W 8N22W 5N35W 5N45W 10N58W.
BESIDES FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...
WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE
OF THE AXIS BETWEEN 43W-52W.

...DISCUSSION...

THE GULF OF MEXICO...
LARGE ELONGATED UPPER TROUGH EXTENDS FROM THE W ATLC INTO THE NE
GULF WITH AN EMBEDDED UPPER LOW ALONG THE COAST NEAR THE GA/SC
BORDER. AN UPPER LOW IS OVER THE NORTHERN YUCATAN PENINSULA. THE
REMAINDER OF THE GULF IN UNDER THE INFLUENCE OF A BUILDING RIDGE
ANCHORED ON AN UPPER HIGH LOCATED OVER SOUTH MEXICO. A SURFACE
TROUGH EXTENDS ALONG THE BASE OF THE UPPER TROUGH ACROSS S
FLORIDA INTO THE GULF TO THE COAST OF LOUISIANA. THIS TROUGH IS
WELL DEFINED IN THE WIND FIELD...AND IS ALREADY AIDING IN THE
DEVELOPMENT OF SHOWERS AND TSTMS OVER MIAMI-DADE COUNTY AND THE
FLORIDA KEYS. SOME SHOWERS/ ISOLATED TSTMS ARE ALSO SEEN ALONG
THE TROUGH AXIS...MAINLY NEAR 28N92W. A SFC RIDGE IS SLOWLY
BUILDING OVER THE SOUTHEAST U.S. AND THE NE GULF BEHIND THE SFC
TROUGH. LIGHT E TO SE WINDS DOMINATES MUCH OF THE AREA.

THE CARIBBEAN SEA...
INTERESTING FEATURE OF THE DAY IS A LARGE AREA OF CLOUDINESS AND
SHOWERS OVER THE NW CARIBBEAN ASSOCIATED WITH A BROAD AREA OF
LOW PRESSURE AND SFC TROUGH EXTENDING FROM EXTREME W CUBA TO THE
GULF OF HONDURAS. A DIFFLUENT PATTERN ALOFT ASSOCIATED WITH A
RIDGE/ANTICYCLONE CENTERED NEAR 15N85W IS ENHANCING THIS
CONVECTIVE ACTIVITY THAT IS SPREADING OVER THE CAYMAN ISLANDS
AND E-CENTRAL CUBA. A NEAR 60 NM WIDE BAND OF MODERATE TO
ISOLATED STRONG CONVECTION IS ALSO EAST OF THE SFC LOW/TROUGH
AND EXTENDS FROM THE ATLC COAST OF NICARAGUA ALL THE WAY N TO
20N83W. A 1009 MB SFC LOW IS ANALYZED ON THE 1200 UTC SURFACE
MAP NEAR 19N86W. THIS LOW IS FORECAST TO SLOWLY DRIFT NORTHWARD.
UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR DEVELOPMENT. A PLUME OF
MID-HIGH LEVEL CLOUDINESS AND POSSIBLE SHOWERS IS STREAMING BY
WSW UPPER LEVEL WINDS ACROSS THE NW CARIBBEAN AND CUBA INTO THE
W ATLC. THE TYPICAL LOW OVER NORTHERN COLOMBIA IS PRODUCING SOME
SHOWERS AND ISOLATED TSTMS JUST OFF THE COLOMBIA COAST. COSTA
RICA AND PANAMA ARE UNDER THE INFLUENCE OF THE EPAC ITCZ. TRADE
WIND SHOWERS ARE POSSIBLE ACROSS THE REMAINDER OF THE BASIN. TWO
TROPICAL WAVES ARE ALONG 60W AND 70W. SEE TROPICAL WAVE SECTION
FOR DETAILS.

THE ATLANTIC OCEAN...
WSW UPPER LEVEL FLOW TO THE E/SE OF A LARGE ELONGATED UPPER
TROUGH IS PROVIDING PLENTY OF MOISTURE FOR PRECIPITATION ACROSS
THE W ATLC. THIS UPPER SYSTEM IS SUPPORTING A 1010 MB SFC LOW
CENTERED NEAR 29N71W  AND TROUGH THAT EXTENDS FROM THE LOW TO
SOUTH FLORIDA INTO THE GULF OF MEXICO. THIS LOW IS FORECAST TO
MOVE NE AND N OF THE AREA DURING THE NEXT 24 HOURS. IR IMAGERY
AND LIGHTNING DATA DETECT A BAND OF MODERATE CONVECTION WELL
AHEAD OF THE LOW/TROUGH ALONG 22N67W 26N63W 31N58W IN A
DIFFLUENT ZONE BETWEEN THE EXTENSIVE TROUGHING AND RIDGING TO
THE E. WV IMAGERY SHOWS A WEAK SHORTWAVE RIDGE EXTENDING NE FROM
HISPANIOLA TO BEYOND 31N52W. ANOTHER UPPER RIDGE DOMINATES THE E
ATLC ANCHORED ON A HIGH LOCATED OVER THE CAPE VERDE ISLANDS. IN
BETWEEN THESE RIDGES...THERE IS A WEAK UPPER TROUGH THAT ENTERS
THE FORECAST NEAR 31N22W THEN CONTINUES SW INTO THE DEEP TROPICS
JUST E THE WINDWARD ISLANDS. AT THE SURFACE...A 1023 MB HIGH IS
NEAR 28N40W COVERING THE DISCUSSION AREA E OF 60W. A MOSTLY DRY
AND STABLE ATMOSPHERE COVERS THE AREA WITH ONLY PATCHES OF
LOW/MID CLOUDS. THIS HIGH IS ALSO PRODUCING A LARGE AREA OF
MODERATE TRADE WINDS.

$$
GR




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