[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 232320
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON 23 MAY 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
2245 UTC.

...TROPICAL WAVES...

CENTRAL ATLC TROPICAL WAVE ALONG 41W S OF 11N MOVING W 10-15
KT.  THE SATELLITE SIGNATURE WITH THIS WAVE IS POOR AND
PARTIALLY OBSCURED BY AN ADVANCING AFRICAN DUST SURGE.  POSITION
IS BASED MAINLY ON EXTRAPOLATION. WIDELY SCATTERED MODERATE
CONVECTION IS NOTED IN THE VICINITY OF THE WAVE FROM 1N-5N
BETWEEN 36W-44W BUT THIS ACTIVITY IS CONFINED WITHIN THE ITCZ
AND IS UNORGANIZED.

E CARIBBEAN TROPICAL WAVE ALONG 65W S OF 14N MOVING W 15 KT.
WHILE THE SATELLITE SIGNATURE WITH THIS WAVE HAS BEEN POOR...NEW
CONVECTION IS OBSERVED DEVELOPING TO THE WEST OF THE ESTIMATED
POSITION OVER W VENEZUELA AND E COLOMBIA.  SCATTERED STRONG
ACTIVITY FROM 5N-9N BETWEEN 66W-70W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N10W 10N25W 2N52W. WIDELY
SCATTERED STRONG CONVECTION OVER SW AFRICA FROM 8N-14N BETWEEN
9W-15W.  SIMILAR ACTIVITY FROM 4N-8N BETWEEN 21W-33W.  WIDELY
SCATTERED MODERATE CONVECTION FROM 1N-4N BETWEEN 35W-44W.

...DISCUSSION...

GULF OF MEXICO...
A SHARP UPPER TROF BISECTS THE GLFMEX FROM N FLORIDA SW ACROSS
CENTRAL MEXICO NEAR MEXICO CITY. THE TROUGH CURRENTLY DELINEATES
DEEP-LAYERED TROPICAL MOISTURE OVER THE CARIBBEAN FROM A VERY
DRY/STABLE ENVIRONMENT TO THE WEST OVER THE W GLFMEX. THIS WAS
EVIDENCED BY THE 1200 UTC SOUNDING DATA FROM MIAMI AND JAMAICA
WHICH SHOWED PRECIPITABLE WATER VALUES OF 1.17 AND 2.06 INCHES
RESPECTIVELY.  AS SUCH...THE EVOLUTION OF THE UPPER TROUGH WILL
LIKELY BE A BIG PLAYER IN THE WEATHER OVER THE NEXT FEW DAYS.
EVALUATION OF WATER VAPOR IMAGERY INDICATES THE TROUGH IS
INCHING SLOWLY NWD AS STRONG RIDGING TRIES TO BUILD NWD FROM THE
W CARIBBEAN.  THIS SHOULD ALLOW MOISTURE VALUES TO INCREASE OVER
FLORIDA THROUGH WED WITH IMPROVING CHANCES OF AFTERNOON SHOWERS/
TSTMS.  AT THE SAME TIME...A LARGE CLOSED LOW CURRENTLY OVER THE
NE UNITED STATES AND W ATLC IS EXPECTED TO AMPLIFY SWD PUSHING A
COLD FRONT CURRENTLY OVER THE S UNITED STATES OFF THE N GULF
COAST TUE MORNING.  UPPER LEVEL DYNAMICS APPEAR MARGINAL WITH
WIDELY SCATTERED TO LOCALLY SCATTERED SHOWERS/TSTMS EXPECTED
ALONG THE FRONT MAINLY OVER THE NE GULF AND CENTRAL TO N FLORIDA
TUE.  FRONT WEAKENS WED AS IT PUSHES THROUGH CENTRAL FLORIDA
EXTENDING FROM ABOUT LAKE OKEECHOBEE TO SE LOUISIANA BY WED
EVENING.  LOW LEVEL MOISTURE POOLING SHOULD BE SUFFICIENT TO
SQUEEZE OUT WIDELY SCATTERED SHOWERS/TSTMS ALONG THE BOUNDARY
ESPECIALLY DURING THE PEAK AFTERNOON HEATING HOURS.
THEREAFTER...UPPER TROUGH AXIS IS FORECAST TO SWING SEWD
RESULTING IN DRYING ACROSS THE ENTIRE GLFMEX AND FLORIDA WITH
WHAT REMAINS OF THE SURFACE BOUNDARY EXPECTED TO DRIFT SWD OVER
S FLORIDA.

CARIBBEAN...
WELL DEFINED MIDDLE TO UPPER LEVEL RIDGE DOMINATES THE ENTIRE
CARIBBEAN EXTENDING E/W FROM THE WINDWARD ISLANDS THROUGH 16N75W
OVER W CUBA.  AT THE SURFACE...TROUGH EXTENDS ACROSS THE AREA
FROM THE N LEEWARD ISLANDS SW TO A 1009 MB LOW S OF JAMAICA NEAR
16.5N79W CONTINUING ACROSS CENTRAL AMERICA NEAR THE
NICARAGUA/HONDURAS BORDER.  THE TROUGH IS CURRENTLY PRODUCING
SHOWERS/THUNDERSTORMS WITH WIDELY SCATTERED ACTIVITY WITHIN 100
NM EITHER SIDE OF BOUNDARY FROM JAMAICA EWD. THE BOUNDARY IS
EXPECTED TO SLOWLY DRIFT NWD DURING THE NEXT SEVERAL DAYS
KEEPING ENHANCED SHOWER/THUNDERSTORMS ACTIVITY OVER THE CENTRAL
AND E CARIBBEAN MAINLY N OF 15N. ELSEWHERE...WIDELY SCATTERED
SHOWERS/THUNDERSTORMS ARE NOTED OVER S MEXICO AND CENTRAL
AMERICA FROM NICARAGUA NWD THROUGH THE ISTHMUS OF TEHUANTEPEC.
THIS ACTIVITY APPEARS RELATED TO UPPER DIVERGENCE ASSOCIATED
WITH A 50-80 KT UPPER JET EXTENDING AROUND THE N PERIPHERY OF
THE RIDGE FROM THE YUCATAN PENINSULA NEWD INTO THE W ATLC.  THE
UPPER JET IS EXPECTED TO WEAKEN SLIGHTLY ON TUE PRIOR TO BEING
AMPLIFIED WED AND THU AS UPSTREAM TROUGH DIGS SWD.
FINALLY...MOISTURE OVER S AMERICA HAS SPREAD INTO THE SW
CARIBBEAN SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS S OF 13N W
OF 75W INCLUDING NICARAGUA...COSTA RICA...AND PANAMA.  THIS
MOISTURE IS EXPECTED TO CONTINUE WESTWARD INTO THE PACIFIC
WITHIN THE NEXT DAY OR SO.

ATLANTIC...
MAIN WEATHER MAKER IS A COMPLEX AREA OF LOW PRES OVER THE CNTRL
ATLC WATERS...WITH 1004 LOW CENTERED NEAR 26N51W.  A TROUGH
TRAILS SWD FROM THE LOW TO THE N LEEWARD ISLANDS. WIDESPREAD
CLOUDINESS AND SCATTERED SHOWERS/TSTMS EXTEND UP TO 800 NM E OF
THE LOW/TROUGH N OF 20N AND WITHIN 100 NM EITHER SIDE OF TROUGH
S OF 20N. THIS SYSTEM IS BEING FORCED BY A MID-LEVEL SHORTWAVE
ALONG 47W WHICH IS EXPECTED TO AMPLIFY RESULTING IN GALE
CONDITIONS DEVELOPING TO THE E/SE OF THE SURFACE LOW WITHIN THE
NEXT 6 TO 12 HOURS.  THE LOW IS FORECAST TO LIFT N OF THE AREA
BY TUE AFTERNOON BUT SHOWERS/TSTMS WILL CONTINUE S AND E OF THE
TRAILING TROUGH FROM ROUGHLY 32N37W SWD THROUGH 21N50W TO
19N65W.   OVER THE W ATLC...BROAD TROUGH WELL N OF THE AREA IS
PRODUCING CONFLUENCE AND DRY/STABLE CONDITIONS ALOFT W OF 50W.
IN THE FAR E ATLC...A SHARP TROF EXTENDING 30W PENETRATES WELL
INTO THE TROPICAL ATLC WITH UPPER DIFFLUENCE TO ITS S AND E
SUPPORTING ENHANCED ITCZ ACTIVITY E OF 35W.  AFRICAN DUST
CONTINUES OVER PORTIONS OF THE CENTRAL AND E ATLC...GENERALLY E
OF A LINE FROM 20N44W TO 5N35W.

$$
RHOME


WWWW
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