[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 132349
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI APR 13 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
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.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N10W 2N20W 1N35W...CROSSING THE
EQUATOR AT 45W THEN INLAND OVER SOUTH AMERICA NEAR 1S50W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 80-100
NM OF THE AXIS FROM 22W-28W. AN AREA OF STRONG CONVECTION IS
MOVING OFF THE AFRICAN COAST AND COVERS FROM 4N-11N BETWEEN
7W-12W. A CLUSTER OF SIMILAR CONVECTION IS NEAR 5N13W.

...DISCUSSION...

GULF OF MEXICO...
A DEEPENING LOW PRES SYSTEM OVER NEW MEXICO AND N TEXAS WILL
MOVE ENE ACROSS THE SE US GENERATING SEVERE WEATHER CONDITIONS
FROM TEXAS TO THE CAROLINAS TONIGHT AND TOMORROW. SEVERAL
WATCHES/WARNINGS HAVE BEEN ISSUED. THE ASSOCIATED COLD
FRONT...CURRENTLY OVER CENTRAL TEXAS AND COAHUILA MEXICO IS
FORECAST TO ENTER THE NW CORNER OF THE GULF EARLY SATURDAY AND
WILL EXTEND FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE
EARLY SUNDAY MORNING. MODERATE TO STRONG NLY WINDS OF 20 TO 30
KT WITH GUSTY GALE FORCE WILL FOLLOW THE FRONT. THIS FEATURE IS
EXPECTED TO REACH SOUTH FLORIDA SUNDAY AFTERNOON. SLY WINDS OF
20 TO 25 KT ARE NOW BLOWING ACROSS THE GULF AHEAD OF THE COLD
FRONT. ALOFT...SWLY WIND FLOW DOMINATES THE GULF AHEAD OF A
STRONG SHORT WAVE TROUGH THAT RUNS FROM CENTRAL NEW MEXICO TO
NORTHERN MEXICO. THESE WINDS ARE TRANSPORTING UPPER LEVEL
MOISTURE/HIGH CLOUDS FROM THE EPAC INTO CENTRAL MEXICO AND THE
GULF. THE MOSAIC DOPPLER RADAR SHOWS A NARROW LINE OF STRONG
SHOWERS AND TSTMS RELATED TO THE COLD FRONT OVER CENTRAL TEXAS.

CARIBBEAN SEA...
THE MAIN WEATHER FEATURE ACROSS THE CARIBBEAN IS A BROAD UPPER
LEVEL RIDGE THAT COVERS THE ENTIRE BASIN AND CENTRAL AMERICA.
IT IS ANCHORED ON A HIGH CENTERED OVER THE SW CARIBBEAN NEAR
13N80W. UPPER LEVEL MOISTURE IS BEING ADVECTED FROM THE EPAC
OVER CENTRAL AMERICA AND THE NW CARIBBEAN BY THE SLY WIND FLOW
ON THE WEST SIDE OF THIS ANTICYCLONE. CLUSTERS OF MODERATE
CONVECTION ARE SEEN OVER W PANAMA AND GUATEMALA. THE EPAC ITCZ
AXIS EXTENDS ACROSS PANAMA AND COSTA RICA ALSO GENERATING SOME
SHOWER ACTIVITY. HEAT AFTERNOON SHOWERS/ISOLATED TSTMS ARE OVER
CENTRAL/EASTERN CUBA. THE REMAINDER OF THE BASIN IS PRETTY QUIET
WITH THE TYPICAL PATCHES OF LOW LEVEL MOISTURE MOVING FROM THE
TROPICAL N ATLC INTO THE EASTERN CARIBBEAN. MODERATE TO STRONG
EASTERLY TRADE WINDS DOMINATE THE REGION. A COLD FRONT IS
FORECAST TO MOVE ACROSS THE YUCATAN CHANNEL/WESTERN CUBA SUNDAY
EVENING.

ATLANTIC OCEAN...
A BROAD UPPER RIDGE FROM THE CARIBBEAN ALSO EXTENDS ACROSS THE
W-CENTRAL ATLC WHILE A DEEP LAYERED TROUGH REMAINS OVER THE E
ATLC. A COUPLE OF FRONTAL BOUNDARIES LIE OVER THE FORECAST AREA.
ONE IS A DYING COLD FRONT THAT ENTERS THE AREA NEAR 32N64W THEN
CONTINUES SW TO NEAR THE NORTHERN BAHAMAS. THE SECOND ONE
EXTENDS SE FROM A 1009 MB SFC LOW LOCATED NEAR 31N59W TO 26N40W
THEN NE AND N TO ANOTHER SFC LOW OVER THE AZORES. THE FRONT
COMBINED WITH UPPER LEVEL DIFFLUENCE IS CREATING A BAND OF
MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS N
OF 25N BETWEEN 30W-55W. A SWIRL OF LOW CLOUDS IS ASSOCIATED WITH
THE 1009 MB LOW. SOUTH OF THE COLD FRONT A RIDGE DOMINATES MOST
OF THE E-CENTRAL ATLC. THIS FEATURE IS PROVIDING FAIR WEATHER
AND MAINLY LIGHT TO MODERATE TRADES THROUGHOUT THE REGION. A
BAND OF UPPER LEVEL MOISTURE/HIGH CLOUDS EXTENDS FROM N SOUTH
AMERICA ALL THE WAY ENE TO W AFRICA CROSSING SOUTH OF THE CAPE
VERDE ISLANDS. THIS UPPER LEVEL MOISTURE IS RELATED TO A
TROPICAL JETSTREAM WITH CORE WINDS OF 70-90 KT.

$$
GR


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