[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141800
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON 14 FEB 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM
THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON
SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N1W 2N20W 1N40W 2N50W. SCATTERED
MODERATE CONVECTION FROM 1N-5N BETWEEN 9W-13W AND FROM 1N-4N
BETWEEN 30W-37W.

...DISCUSSION...

GULF OF MEXICO...
A WEAK COLD FRONT MOVING ACROSS THE TENNESSEE VALLEY REGION OF
THE UNITED STATES TRAILS SWD OVER S LOUISIANA AND ALONG THE SE
TEXAS COAST AS A REMNANT FRONTAL TROUGH. THERE IS LITTLE
TEMPERATURE GRADIENT ACROSS THE BOUNDARY ALTHOUGH MOIST SW FLOW
JUST AHEAD OF THE TROUGH IS PRODUCING PATCHES OF SEA FOG UP TO
150 NM OFF THE TX/LA COAST. FURTHER E...A SHARP UPPER LEVEL
SHORTWAVE TROUGH OVER THE E UNITED STATES IS PRODUCING A LINE OF
STRONG SHOWERS/THUNDERSTORMS OVER N FLORIDA INTO THE NE GULF.
THE UPPER TROUGH IS FORECAST TO LIFT QUICKLY NEWD WITH
ASSOCIATED LINE OF SHOWERS/THUNDERSTORMS GRADUALLY WEAKENING
INTO A NARROW LINE OF WIDELY SCATTERED SHOWERS AS IT SAGS SWD
OVER FLORIDA.  MIDDLE TO UPPER LEVEL RIDGING WILL THEN BUILD IN
BEHIND THE EXITING SHORTWAVE PRODUCING MAINLY DRY/TRANQUIL
CONDITIONS OVER THE ENTIRE AREA THROUGH MID-WEEK.  THE NEXT COLD
FRONT TO AFFECT THE AREA WILL MOVE OFF THE TEXAS COAST LATE WED
NIGHT BUT WILL BE MOISTURE STARVED WITH LITTLE SIGNIFICANT
WEATHER IN ADVANCE.  EXPECT A RETURN TO A TYPICAL WINTER REGIME
OF POST-FRONTAL NLY FLOW AND COLD AIR ADVECTION BY LATE WEEK AS
THE FRONT SWEEPS THROUGH THE GULF.

CARIBBEAN...
THE CARIBBEAN CONTINUES TO BE DOMINATED BY A MIDDLE TO UPPER
LEVEL RIDGE EXTENDING ALONG THE N COAST OF VENEZUELA NWD ACROSS
HISPANIOLA INTO THE W ATLC.  RESULTING STRONG SUBSIDENCE AND
VERY DRY/STABLE CONDITIONS ALOFT EXIST ACROSS THE ENTIRE AREA.
AS SUCH...CLOUDINESS AND SHOWER ACTIVITY IS PRIMARILY FOCUSED
ALONG LOW LEVEL MOISTURE BOUNDARIES.  THE MOST PROMINENT OF
THESE BOUNDARIES TRAILS SWD FROM A DISSIPATING ATLC STATIONARY
FRONT OVER THE N LEEWARD ISLANDS TO THE CENTRAL CARIBBEAN NEAR
13N72W.  THE BOUNDARY IS ACCOMPANIED BY 120 NM WIDE LINE OF
SCATTERED SHOWERS.  A SECOND AREA OF SCATTERED SHOWERS IS
LOCATED SW OF JAMAICA FROM 15N-18N BETWEEN 79W-83W.  BOTH AREAS
OF SHOWER ACTIVITY ARE MOVING QUICKLY WESTWARD WITHIN THE
MODERATE TO STRONG ELY FLOW WHICH HAS BECOME ESTABLISHED ACROSS
MUCH OF THE CARIBBEAN AS HIGH PRES BUILDS SWD OVER THE W ATLC.
THE PRES GRADIENT IS FORECAST TO TIGHTEN A BIT FURTHER THROUGH
24 HOURS THEN BEGIN RELAXING WED.

ATLANTIC...
THE W ATLC IS UNDER THE INFLUENCE OF DEEP-LAYERED RIDGING WITH
RATHER DRY CONDITIONS NOTED THROUGHOUT THE ENTIRE DEPTH OF THE
ATMOSPHERE.  A COLD FRONT IS SLIDING DOWN THE E FLANK OF THE
RIDGE NOW ENTERING THE AREA E OF BERMUDA ALONG 32N52W AND
TRAILING SWD ALONG 29N60W THEN NW BEYOND 32N72W. HOWEVER...THIS
FEATURE IS MOISTURE STARVED AND LACKING UPPER LEVEL DYNAMICS
WITH ONLY A VERY NARROW BAND OF WIDELY SCATTERED SHOWERS RIGHT
ALONG THE LEADING EDGE. THE WEATHER BECOMES MORE ACTIVE OVER THE
CENTRAL ATLC COURTESY OF A STATIONARY FRONTAL BOUNDARY ALONG
31N45W 25N55W TO THE N LEEWARD ISLANDS NEAR ANGUILLA.  WHILE THE
LOW LEVEL THERMAL GRADIENT IS WEAKENING WITH THIS
FEATURE...SUFFICIENT MOISTURE POOLING AND DYNAMICS ASSOCIATED
WITH A WEAK SHORTWAVE TROUGH ALONG 60W IS PRODUCING SCATTERED
SHOWERS WITHIN 125 NM EITHER SIDE OF BOUNDARY.  THE FRONTAL
BOUNDARY SHOULD CONTINUE TO WASH OUT OVER THE CENTRAL ATLC
WATERS DURING THE NEXT FEW DAYS BUT SCATTERED SHOWERS WILL
REMAIN.  OVER THE FAR E ATLC...A LARGE DEEP-LAYERED LOW IS
CENTERED W OF THE CANARY ISLANDS NEAR 30N20W WITH ATTENDANT
TROUGH TRAILING SWD TO THE CAPE VERDE ISLANDS.  CONFLUENT FLOW
INTO THE BASE OF THE TROUGH IS PRODUCING STRONG SUBSIDENCE AND
DRY AIR FROM 10N-20N E OF 40W TO THE COAST OF AFRICA. AT THE
SURFACE... A DEEPENING 1011 MB SFC LOW IS LOCATED 200-300 NM WNW
OF THE CANARY ISLANDS.  MOST OF THE SIGNIFICANT WEATHER WITH
THIS FEATURE IS N OF THE AREA WITH ONLY A SMALL AREA OF
SCATTERED SHOWERS NEAR THE CENTER OF THE LOW ITSELF.  IN
FACT...SATELLITE IMAGERY SHOWS MAINLY DRY/STABLE CONDITIONS TO
THE SOUTH OF THE LOW DUE IN PART TO AN AREA OF DUST WHICH HAS
PROPAGATED OFF THE CONTINENT OF AFRICA AND IS NOW MOVING WEST
WITHIN THE LOW LEVEL ELY FLOW.  THE LEADING EDGE OF THE HIGHEST
CONCENTRATION OF DUST EXTENDS FROM THE CANARY ISLANDS SW TO
13N54W WITH VISIBILITIES DROPPING BELOW 5 MILES.

$$
RHOME




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