[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 261728
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT 26 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1645 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N1W 3N20W EQ40W 1S50W.  AREA OF
SCATTERED MODERATE CONVECTION MOVING RAPIDLY WESTWARD FROM THE
EQUATOR NWD TO 5N BETWEEN 17W-20W.  WIDELY SCATTERED MODERATE
CONVECTION WITHIN 60 NM EITHER SIDE OF AXIS BETWEEN 29W-45W.

...DISCUSSION...

GULF OF MEXICO...
COMPLEX AND ACTIVE PATTERN IS UNFOLDING OVER THE AREA AS A
REMNANT FRONTAL TROUGH OVER THE N GULF ALONG 29N LIFTS NWD
TRIGGERING AN AREA OF NUMEROUS SHOWERS/THUNDERSTORMS OVER THE NE
GULF AND N FLORIDA.  AT THE SAME TIME...THE S STREAM UPPER JET
REMAINS ACTIVE WITH YET ANOTHER POTENT SHORTWAVE DISTURBANCE
TRACKING EWD ACROSS THE SW UNITED STATES.  THE SHORTWAVE IS
ACCOMPANIED BY A STRONG...150 KT...SUBTROPICAL JET EXTENDING
ACROSS THE S UNITED STATES FROM TEXAS EWD THROUGH THE CAROLINAS.
ADDITIONALLY...A COLD CONTINENTAL AIRMASS IS OBSERVED MOVING SWD
ALONG THE E SLOPES OF THE ROCKIES THROUGH TEXAS. THIS EVOLVING
PATTERN IS PRODUCING A SECOND AREA OF SHOWERS/THUNDERSTORMS OVER
E TEXAS.  THE AFOREMENTIONED SURFACE BOUNDARIES SHOULD
CONSOLIDATE OVER THE NEXT 12-24 HOURS AS THE UPPER LEVEL
SHORTWAVE IGNITES CYCLOGENESIS IN THE VICINITY OF SE
TEXAS/LOUISIANA.  INCREASING SLY FLOW TO THE EAST WILL PRODUCE
FRONTOGENESIS ALONG THE N GULF COAST TODAY. THE DEVELOPING LOW
WILL THEN TRACK NEWD AND STRENGTHEN OVER THE TENNESSEE VALLEY
DRAGGING THE CONTINENTAL AIR CURRENT OVER TEXAS SWD INTO N
MEXICO AND ACROSS THE GLFMEX.  LEADING EDGE OF THIS AIRMASS IS
EXPECTED TO MOVE OFF THE SE COAST OF TEXAS LATE TONIGHT THEN
MARCH QUICKLY ACROSS THE GULF CLEARING S FLORIDA MONDAY EVENING.
UPPER LEVEL DYNAMICS/LIFT APPEAR MOST IMPRESSIVE OVER THE
CENTRAL AND NE GULF WITH THE STRONG SUBTROPICAL JET.
SHOWERS/THUNDERSTORMS SHOULD DEVELOP EARLY SUNDAY AS THE COLD
FRONT MOVES OFF TEXAS.  FURTHER S...THE ATTENDANT UPPER TROUGH
IS EXPECTED TO TRACK FAR ENOUGH S TO PRODUCE WEAK TO MODERATE
LIFT/DYNAMICS ALONG THE S PORTION OF THE FRONT ASSISTING
SCATTERED SHOWERS/THUNDERSTORMS OVER THE SE GULF AND S FLORIDA
LATE MONDAY.

CARIBBEAN...
STRONG MID/UPPER RIDGING CONTINUES OVER THE CARIBBEAN ANCHORED
BY A WELL-DEFINED ANTICYCLONE CENTERED JUST E OF NICARAGUA NEAR
12N81W.  RESULTING UPPER LEVEL FLOW IS GENERALLY NW AND QUITE
DRY WITH STRONG SUBSIDENCE CREATING A STABLE PATTERN ALOFT.
SHOWER ACTIVITY REMAINS LIMITED WITH INSUFFICIENT MOISTURE ALSO
NOTED IN THE LOWER LEVELS. ONLY A FEW ISOLATED LOW-TOPPED
SHOWERS ARE CURRENTLY NOTED. THESE CONDITIONS SHOULD PREVAIL
THROUGH THE WEEKEND PRIOR TO THE APPROACH OF THE NEXT COLD FRONT
MONDAY.  SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE OVER W
CUBA...YUCATAN CHANNEL...AND THE YUCATAN CHANNEL MONDAY
AFTERNOON OR MONDAY NIGHT.

ATLANTIC...
BUILDING MIDDLE TO UPPER LEVEL RIDGE IS NOTED OVER THE W ATLC
AHEAD OF A AMPLIFYING TROUGH OVER THE CENTRAL UNITED STATES.
THE RIDGE IS EXPECTED TO CONTINUE BUILDING NWD TOWARD THE
CANADIAN MARITIMES THROUGH SUNDAY NIGHT. UPSTREAM COLD FRONT
EMERGES OFF THE SE UNITED STATES COAST SUNDAY NIGHT INTO EARLY
MONDAY WITH GUIDANCE INDICATED THE POSSIBILITY OF
SHOWERS/THUNDERSTORMS IN ADVANCE. SHIFTING EWD...BROAD UPPER
TROUGH DOMINATES THE CENTRAL ATLC WATERS BETWEEN 40W-70W WITH
ASSOCIATED COLD FRONT ENTERING THE AREA ALONG 32N43W AND
EXTENDING SW TO 26N54W THEN DISSIPATING TO 24N60W. WIDELY
SCATTERED SHOWERS/ISOLATED TSTMS ARE WITHIN 120 NM AHEAD OF THE
FRONT E OF 55W.  OVER THE E ATLC...AN E/W ORIENTED DEEP-LAYERED
RIDGE BISECTS THE AREA WITH UPPER LEVEL AXIS EXTENDING FROM
AFRICA NEAR MAURITANIA TO N PORTIONS OF S AMERICA.  SURFACE
RIDGE AXIS EXTENDS FROM THE CANARY ISLANDS TO THE WINDWARD
ISLANDS.  MODERATE TRADES ARE S OF THE RIDGE AXIS.  VERY DRY
CONDITIONS CONTINUE TO LIMIT SIGNIFICANT CLOUDS OR PRECIPITATION
AND ITCZ ACTIVITY REMAINS CONFINED NEAR THE EQUATOR.

$$
RHOME


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