[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 172337
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT FEB 17 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 3N20W 2N35W CROSSING THE
EQUATOR AT 41W INTO NE BRAZIL NEAR 3N47W. SCATTERED MODERATE TO
ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS FROM
20W-40W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ARE OVER NE BRAZIL NEAR THE ITCZ AXIS.

...DISCUSSION...
GULF OF MEXICO...
A NEW COLD FRONT HAS ENTERED THE GULF TODAY. THIS FRONT IS
EMBEDDED WITHIN DRY AIR...THUS LITTLE IN THE FORM OF SHOWERS IS
EXPECTED. THIS FEATURE WILL RAPIDLY MOVE ACROSS THE AREA TONIGHT
REINFORCING THE WINTER CONDITIONS ALREADY IN PLACE. THE FRONT IS
FORECAST TO REACH SOUTH FLORIDA LATE TONIGHT. ANOTHER SHOT OF
COLD AND DRY AIR WILL GRIP THE GULF AND THE STATE OF FLORIDA ON
SUNDAY. WINDS WILL BRIEFLY INCREASE TO GALE FORCE BEHIND THE
FRONT OVER THE MIDDLE AND E GULF LATE TONIGHT AND EARLY SUN AS
HIGH PRES BUILDS OVER THE DEEP SOUTH AND NE MEXICO. OVERCAST
LOW/MID CLOUDS WITH EMBEDDED LIGHT RAIN/DRIZZLE ARE COVERING THE
SW GULF INCLUDING THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA.
IN THE UPPER LEVELS...STRONG WLY WINDS ASSOCIATED WITH A
SUBTROPICAL JET COVERS THE ENTIRE GULF. A BROAD UPPER TROUGH
THAT EXTENDS FROM THE GREAT LAKES TO TEXAS WILL MOVE EWD ACROSS
THE E US ON SUNDAY...DIGGING INTO THE E GULF OF MEXICO. THIS
UPPER TROUGH IS SUPPORTING THE COLD FRONT MENTIONED ABOVE.

CARIBBEAN SEA...
A DIFFUSE FRONTAL BOUNDARY EXTENDS FROM THE WINDWARD PASSAGE TO
THE HONDURAS/NICARAGUA BORDER. BROKEN/OVERCAST LOW/MID LEVEL
CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE OVERRUNNING THE
FRONTAL SYSTEM. MODERATE/STRONG EASTERLY TRADE WINDS DOMINATES
THE ENTIRE CARIBBEAN. IN THE   UPPER LEVEL...A BROAD RIDGE
CENTERED OVER THE SW CARIBBEAN IS STILL IN CONTROL OF THE
WEATHER PATTERN ACROSS THE BASIN. THIS RIDGE ALSO DOMINATES
CENTRAL AMERICA AND N SOUTH AMERICA WITH DRY SINKING AIR ALOFT.
THE DRIEST AIR IS LOCATED SOUTH OF HISPANIOLA. OVERCAST LOW/MID
CLOUDS WITH EMBEDDED LIGHT RAIN ARE COVERING THE NW CARIBBEAN W
OF 83W AND THE GULF OF HONDURAS. POCKETS OF LOW LEVEL MOISTURE
WITH MAINLY LIGHT SHOWERS DRIVEN BY THE TRADE WINDS ARE MOVING
FROM THE TROPICAL N ATLC INTO THE E CARIBBEAN. NLY WINDS WILL
INCREASE ACROSS THE NW CARIBBEAN AND W CUBA ON SUNDAY AS HIGH
PRES INVADES THE GULF OF MEXICO.

ATLANTIC OCEAN...
THE SURFACE RIDGE EXTENDS FROM THE CENTRAL GULF OF MEXICO INTO
THE W ATLC W OF THE SLOW MOVING COLD FRONT THAT ENTERS THE AREA
NEAR 32N52W THEN CONTINUES SW ALONG 27N60W TO THE TURKS AND
CAICOS ISLANDS WHERE IT BECOMES STATIONARY. IT CONTINUES ACROSS
CUBA INTO THE CARIBBEAN AS A DYING FRONTAL SYSTEM.  A 220 NM
WIDE BAND OF OVERCAST LOW/MID LEVEL CLOUDS AND ISOLATED SHOWERS
IS RELATED TO THE FRONT. THE ASSOCIATED UPPER LEVEL TROUGH DIPS
S OVER THE NW ATLC AND OVER THE E US WITH MOST OF THE UPPER
LEVEL ENERGY N OF THE REGION. A SUBTROPICAL JET WITH WINDS OF 90
TO 130 KT THAT COVERS THE GULF EXTENDS INTO THE W ATLC ACROSS N
FLORIDA THEN NE TO 32N70W AND BEYOND. UPPER RIDGE ANCHORED IN
THE SW CARIBBEAN EXTENDS AN AXIS NE ACROSS PUERTO RICO/VIRGIN
ISLANDS TO BEYOND 32N42W. AN UPPER TROUGH REMAINS OVER THE E
ATLC EXTENDING FROM THE MADEIRA/CANARY ISLANDS INTO THE TROPICAL
ATLC NEAR 12N40W. AT THE SURFACE...THE E ATLC IS DOMINATED BY A
SURFACE RIDGE THAT EXTENDS FROM A 1028 MB HIGH JUST SE OF THE
AZORES TO THE NE CARIBBEAN SUPPLYING MOSTLY FAIR WEATHER AND
MODERATE TRADES ACROSS A GOOD PORTION OF THE REGION. ONLY
PATCHES OF LOW LEVEL MOISTURE ARE UNDER THE INFLUENCE OF THIS
RIDGE.

$$
GR



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