[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202339
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE FEB 20 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 6N10W 5N20W 3N30W CROSSING THE
EQUATOR AT 36W INTO NE BRAZIL. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE WITHIN 40-60 NM OF THE AXIS BETWEEN 16W-23W AND
BETWEEN 30W-35W. SIMILAR CONVECTION IS OVER NE BRAZIL.

...DISCUSSION...
GULF OF MEXICO...
THE WEST PORTION OF A 1026 MB SFC HIGH LOCATED E OF FLORIDA
NEAR 30N70W IS EXTENDING INTO THE GULF...PRODUCING 10-20 KT SLY
RETURN FLOW OVER THE BASIN. STRONG MID/UPPER RIDGE CENTERED OVER
N GUATEMALA/BELIZE COVERS THE ENTIRE GULF AND SOUTHERN MEXICO.
THIS RIDGE WILL REMAIN IN PLACE DURING THE NEXT 24-48 HOURS. A
ZONAL FLOW DOMINATES THE NORTHERN GULF WATERS. DRY/STABLE MID TO
UPPER AIR EXISTS S OF 25N WITH MORE MOISTURE AVAILABLE TO THE N.
THIS MOISTURE IS BEING TRANSPORTED BY A SUBTROPICAL JET THAT
CROSSES N MEXICO...TEXAS AND THE SE US WITH A CORE WINDS OF
110-130 KT. SCATTERED TO BROKEN LOW TO MID CLOUDS ARE IN THE
GULF MAINLY ACROSS THE E HALF. RETURN FLOW WILL GRADUALLY RELAX
THROUGH MIDWEEK AS THE SFC RIDGING WEAKENS ACROSS THE AREA BUT
WILL INCREASE AGAIN ON SAT AHEAD OF A NEW COLD FRONT APPROACHING
THE TEXAS COAST.

CARIBBEAN SEA...
WEAKENING STATIONARY FRONT ENTERS THE CARIBBEAN NEAR THE LEEWARD
ISLANDS AT 18N64W AND CONTINUES WSW TO NEAR 14N78W. A SFC TROUGH
REMNANT OF AN OLD FRONTAL BOUNDARY IS VERY CLOSE TO THE
NICARAGUA/HONDURAS BORDER AND LIES ALONG 18N84W 14N80W. THIS
TROUGH IS MOVING WWD AND THE CLOUDINESS ASSOCIATED WITH IT IS
ALREADY AFFECTING CENTRAL AMERICA. A BAND OF BROKEN TO OVERCAST
LOW/MID CLOUDS IS RELATED TO THE STATIONARY FRONT. THESE CLOUDS
ARE STILL AFFECTING PUERTO RICO AND THE VIRGIN ISLANDS WITH
LIGHT TO MODERATE SHOWERS. THE STATIONARY FRONT WILL GRADUALLY
WEAKEN AND MOVE TO THE NORTH DURING THE NEXT FEW DAYS. EXTREMELY
DRY/STABLE MID TO UPPER AIR CONTINUES TO HOVER OVER THE
CARIBBEAN...AROUND RIDGING EXTENDING E THROUGH THE BASIN FROM
GUATEMALA. HIGH PRES WILL BUILD N OF AREA GIVING THE CARIBBEAN
SEA MODERATE TO STRONG TRADE WINDS THROUGH THE END OF THE WEEK.
FRAGMENTS OF LOW LEVEL MOISTURE WITH EMBEDDED LIGHT SHOWERS ARE
MOVING ACROSS THE LESSER ANTILLES FROM THE TROPICAL NORTH ATLC.

ATLANTIC OCEAN...
A 1026 MB SFC HIGH IS LOCATED OFFSHORE FLORIDA NEAR 30N70W.
AHEAD OF THIS FEATURE THERE IS A COLD FRONT THAT ENTERS THE AREA
NEAR 31N39W THEN CONTINUES SW TO 25N50W. FRONT IS THEN
STATIONARY FROM THAT POINT TO THE LEEWARD ISLANDS. A 100-130 NM
WIDE BAND OF BROKEN TO OVERCAST LOW/MID CLOUDS IS RELATED TO THE
FRONTAL SYSTEM. SCATTERED TO BROKEN COLD AIR STRATOCUMULUS
CLOUDS ARE FOUND ELSEWHERE BEHIND THE FRONT INCLUDING THE
BAHAMAS. REMAINDER OF THE E AND CENTRAL ATLC SFC PATTERN IS
DOMINATED BY THE SRN PERIPHERY OF A 1023 MB HIGH SITUATED NW OF
THE CANARY ISLANDS NEAR 31N21W. ALOFT...A RIDGE/TROUGH/RIDGE
PATTERN DOMINATES THE FORECAST AREA. A RIDGE IS BUILDING ACROSS
THE W ATLC BEHIND A WEAK UPPER TROUGH EXTENDING ALONG 61W.
ANOTHER RIDGE CENTERED NEAR 20N44W EXTENDS OVER THE REMAINDER OF
THE OCEAN. AN UPPER TROUGH REMAINS INLAND OVER W AFRICA. FAIRLY
DRY MID TO UPPER AIR IS ALSO SEEN BETWEEN 70W-30W.

$$
GR






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