[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251129
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI 25 MAR 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N8W 2N23W 1N40W 1S50W.  WIDELY
SCATTERED MODERATE S OF 3N BETWEEN 10W-25W.  CLUSTER OF MODERATE
CONVECTION WITHIN 60 NM OF 5N16W.  WIDELY SCATTERED MODERATE
WITHIN 45/60 NM OF AXIS BETWEEN 25W-49W.

...DISCUSSION...

GULF OF MEXICO...
STRONG TO SEVERE TSTMS ARE FIRING NEAR AND AHEAD OF A WARM FRONT
FROM NEAR JACKSONVILLE FLORIDA TO TALLAHASSEE TO THE MOUTH OF
THE MISSISSIPPI RIVER.  MOST OF THE WIDELY SCATTERED TSTMS ARE
NOW ONSHORE IN THE FLORIDA PANHANDLE WITH SUPERCELLS POSSIBLE IN
THE REGION.  AN UPPER JETSTREAK IS PROVIDING DYNAMICAL SUPPORT
WHILE THE FRONT SERVES AS A LIFTING MECHANISM USING MOISTURE-
RICH AIR FROM THE SE GULF.  OTHERWISE WSW UPPER FLOW CONTINUES
OVER THE REGION WITH ANY SHORTWAVES N OF THE AREA.  THE WARM
FRONT SHOULD CONTINUE TO PROGRESS NORTHWARD AND DURING THE DAY
LINK INTO A DEVELOPING SURFACE LOW OVER THE TENNESSEE VALLEY.
THE NEXT COLD FRONT WILL WORK ITS WAY INTO THE NW GULF OVERNIGHT
SUN WITH ANOTHER ROUND OF STRONG/POSSIBLY SEVERE TSTMS IN THE
N-CENTRAL AND NE GULF ON SUN.

CARIBBEAN...
INCREASING PRESSURE GRADIENT BETWEEN A 1019 MB HIGH JUST E OF
THE CENTRAL BAHAMAS AND LOW PRESSURE OVER N COLOMBIA IS
PRODUCING WINDS NEAR 25 KT OVER THE TYPICAL ENHANCED WIND REGION
IN THE SW CARIBBEAN. DOMINATING MID/UPPER HIGH HAS BEEN SHOVED
EASTWARD WITH MORE CLIMATOLOGICALLY-FAVORED WLY WINDS
CONTROLLING THE REGION W OF 70W.  THERE STILL ISN'T MUCH
SIGNIFICANT WEATHER WITH ONLY A FEW SHOWERS OVER THE WINDWARD
ISLANDS AND MODERATE SUBSIDENCE KEEPING ANY SIGNIFICANT
CONVECTION LIMITED TO PEAK DIURNAL HEATING.  MODELS HAVE BEEN
FAIRLY CONSISTENT ABOUT BRINGING A FRONT INTO THE NW CARIBBEAN
LATE MON WITH A GOOD CHANCE FOR RAIN AND ISOLATED TSTMS ALONG A
POTENT SPRING COLD FRONT.

ATLANTIC...
SURFACE HIGH PRESSURE IS THE RULE WITH ONE WEAK COLD FRONT IN
THE WESTERN ATLC AND A DISSIPATING ONE OVER THE CANARY ISLANDS.
FIRST COLD FRONT EXTENDS FROM NEAR 31N59W TO 25N70W WITH
ISOLATED TSTMS WITHIN 45 NM OF THE FRONT N OF 27N.  DISTANT
UPPER TROUGH IN THE MID-LATITUDES PROVIDES THE UPPER SUPPORT FOR
THESE TSTMS THOUGH IT IS PROGRESSIVE IN NATURE AND SHOULD
CONTINUE TO SWEEP THE FRONT QUICKLY EASTWARD.  MID/UPPER RIDGING
DOMINATES THE CENTRAL ATLC WITH A DISSIPATING COLD FRONT ALONG A
LINE FROM THE ERN CANARY ISLANDS TO 25N19W.  THE FRONT IS
BREAKING UP WITH BROKEN MIDDLE-LEVEL CLOUDS W OF THE DIFFUSE
BOUNDARY WHICH BASICALLY COVER THE SUBTROPICAL ATLC E OF 40W N
OF 23N.  GENERALLY ZONAL FLOW CONTINUES OVER THE NE ATLC WITH
MID/UPPER RIDGING WEAKENING IN THE DEEP TROPICS.  THE
SUBTROPICAL RIDGE IS ORIENTED FROM NEAR THE CANARY ISLANDS TO A
1021 MB CENTER NEAR 25N46W W TO 23N65W WITH TYPICAL BROKEN LOW
CLOUDS MISSING OVER THE E TROPICAL ATLC.  MORE TYPICAL
LOW/MIDDLE CLOUD CLUSTERS ARE RETURNING OVER THE W TROPICAL ATLC
WITH SPRING-TIME TRADES BACK TO AVERAGE. THE NEARLY CLOUD-FREE
CONDITIONS OF THE FAR TROPICAL E ATLC (SOMEWHAT ENHANCED BY
RECENT AFRICAN DUST/DRY AIR EPISODES) ARE LIKELY TO CHANGE WITH
MODELS FORECASTING THE DEVELOPMENT OF MORE TYPICAL NE TRADES
ORIGINATING FROM THE COLDER WATER AND A PROBABLE RETURN TO THE
MARINE LAYER CLOUDINESS BY EARLY NEXT WEEK.

$$
BLAKE

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