[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 022330
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED 02 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 2N20W 2N50W 3N80W.  SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS S OF 4N BETWEEN 30W-40W.
ISOLATED MODERATE CONVECTION IS S OF 4N BETWEEN 40W-47W.

...DISCUSSION...

GULF OF MEXICO...
A WEAKENING 1016 MB LOW OVER SE LOUISIANA AND ASSOCIATED FRONTAL
SYSTEM CONTINUE TO BE THE MAIN WEATHER MAKER WITH SCATTERED
SHOWERS AFFECTING THE N GULF COAST AND SE UNITED STATES FROM THE
FLORIDA PANHANDLE TO THE SE TIP OF LOUISIANA. THE FRONTAL SYSTEM
CONSISTS OF A WARM FRONT EXTENDING ESE FROM THE LOW TO 28N84W
NEAR TAMPA FLORIDA.  CONVECTION IS MOSTLY N OF THE WARM FRONT. A
WEAK TO MODERATE COLD FRONT TRAILS SWD FROM THE LOW TO THE BAY
OF CAMPECHE THEN INLAND OVER MEXICO ALONG THE E SLOPES OF THE
SIERRA MADRE ORIENTAL MOUNTAINS ALONG 28N90W 18N95W 21N100W
25N100W. OVERCAST CLOUDINESS AND ISOLATED SHOWERS EXISTS BEHIND
THE COLD FRONT IN THE RELATIVELY UNSTABLE ENVIRONMENT CREATED BY
COLD ADVECTION OVER A WARM SEA SURFACE.  OVERCAST CLOUDINESS AND
SHOWERS EXTEND INLAND OVER MEXICO AS POST-FRONTAL NLY FLOW
ENCOUNTERS THE WINDWARD FACING SLOPES.  THE PATTERN ALOFT
CONTINUES TO SLOWLY SHARPEN AS A MID/UPPER TROUGH OVER THE SW
UNITED STATES AND NW MEXICO AMPLIFIES SWD AND MIDDLE TO UPPER
LEVEL RIDGING OVER THE GULF NOSES NWD.  THIS EVOLUTION SHOULD
PRODUCE WEAKENING UPPER LEVEL DYNAMICS/LIFT TONIGHT WHILE THE
LOW AND ATTENDANT WARM FRONT MOVE N OF THE AREA LATER THIS
EVENING.  HOWEVER...LOW LEVEL MOISTURE POOLING WILL CONTINUE TO
GENERATE A NARROW BAND OF WIDELY SCATTERED TO LOCALLY SCATTERED
SHOWERS ALONG THE COLD FRONT AS IT MOVES ACROSS FLORIDA TONIGHT
CLEARING THE S TIP BY EARLY FRI.

CARIBBEAN...
MIDDLE TO UPPER RIDGE REMAINS OVER THE W HALF OF THE CARIBBEAN
ANCHORED BY A WELL-DEFINED ANTICYCLONE OVER CENTRAL AMERICA NEAR
HONDURAS.  OVER THE NE CARIBBEAN...WEAK TROUGHING HAS DEVELOPED
AS A DEEP LAYERED TROUGH OVER THE W ATLC AMPLIFIES AND DIPS S.
THE RESULTING UPPER FLOW OVER THE CARIBBEAN IS PRIMARILY FROM
THE NW WITH VIRTUALLY ALL UPSTREAM MOISTURE STREAMING N OF THE
AREA ACROSS THE GULF AND LEAVING THE CARIBBEAN UNDER STRONG
SUBSIDENCE AND DRY/STABLE CONDITIONS ALOFT. THE LOW LEVELS ARE
ALSO RELATIVELY DRY AS POST-FRONTAL NLY FLOW BEHIND AN ATLC
FRONT FILTERS SWD OVER THE AREA. A THIN LINE OF BROKEN LOW
CLOUDS AND ISOLATED SHOWERS ARE WITHIN 30 NM EITHER SIDE OF THE
LEADING EDGE OF THIS DRIER AIR FROM ANTIGUA TO 17N74W. A FEW
SHOWERS ARE ALSO NOTED ALONG A WEAK LOW LEVEL TROUGH ALONG THE
COAST OF S AMERICA E OF 70W. ADDITIONALLY...THE USUAL AREA OF
OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS IS NOTED INLAND OVER
PORTIONS OF NICARAGUA AND SE HONDURAS AS NLY FLOW ENCOUNTERS
WINDWARD FACING SLOPES OF THE SIERRA MADRE MOUNTAINS.

ATLANTIC WEST OF 45W...
A NEARLY STATIONARY DEEP-LAYERED LOW IS LOCATED ROUGHLY 300 NM
ESE OF BERMUDA WITH A DEEPENING 993 MB STORM FORCE LOW.
ASSOCIATED OCCLUDED FRONT EXTENDS E TO NEAR 31N47W WITH COLD
FRONT TRAILING SWD ALONG 27N46W 22N50W 18N60W THEN WEAKENING TO
THE N LEEWARD ISLANDS NEAR 16N70W. ONLY A NARROW 30 NM WIDE BAND
OF WIDELY SCATTERED SHOWERS ACCOMPANIES THE COLD FRONT.  A
BROKEN STRATOCUMULUS FIELD IS NOTED W OF THE FRONT TO THE
BAHAMAS. WHILE THE STRONGEST DYNAMICS/LIFT WITH THIS PATTERN IS
CONFINED N OF THE AREA...INSTABILITY ASSOCIATED WITH THE COLD
CORE UPPER LOW IS PRODUCING SCATTERED CELLS OF SHOWERS/
THUNDERSTORMS N OF 29N BETWEEN 50W-65W.  WATER VAPOR IMAGERY
INDICATES THE MIDDLE TO UPPER LEVEL TROUGH IS DEEPENING AS A
SHORTWAVE FEATURE SWINGS THROUGH THE BASE. THIS SHOULD SUPPORT
SOME ADDITIONAL STRENGTHENING OF THE SURFACE LOW OVER THE NEXT
24 HOURS AS IT DRIFTS SEWD.  GIVEN THE LARGE SIZE AND RELATIVE
SLOW MOTION OF THIS STRONG SURFACE LOW...A SIGNIFICANT SWELL
EVENT...PERHAPS REACHING 20 FT...SHOULD UNFOLD ESPECIALLY W OF
60W WHERE THE FLOW WILL MAINTAIN A NLY COMPONENT.

ATLANTIC EAST OF 45W...
A SECOND NEGATIVELY-TILTED SHORTWAVE TROUGH IS LOCATED FARTHER E
BETWEEN 30W-40W N OF 20N WITH ATTENDANT 1009 MB SURFACE LOW NEAR
30N40W.  A SURFACE TROUGH TRAILS SWD ALONG 24N37W 16N43W.
UPPER DIFFLUENCE E OF THE TROUGH IS PRODUCING WIDESPREAD
CLOUDINESS AND WIDELY SCATTERED SHOWERS/THUNDERSTORMS WELL E OF
THE COLD FRONT N OF 22N BETWEEN 30W-37W.  UNDER THE INFLUENCE OF
THE LARGER SCALE AND STRONGER W ATLC SYSTEM...THE LOW AND
ASSOCIATED CONVECTION WILL MOVE QUICKLY NWD AND OUT OF THE AREA
DURING THE NEXT 24 HOURS.  SCATTERED SHALLOW TOPPED SHOWERS WILL
REMAIN ALONG A TRAILING LOW LEVEL TROUGH WHICH WILL EXTEND FROM
31N34W TO 20N40W BY THU AFTERNOON.  ELSEWHERE...A PLUME OF
AFRICAN DUST AND VERY DRY LOW LEVEL AIR HAS MOVED OFF THE COAST
AND REACHED AS FAR W AS 33W...INHIBITING CLOUD DEVELOPMENT S AND
E OF THE CAPE VERDE ISLANDS.

$$
FORMOSA





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