[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201755
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON JUN 20 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.

...TROPICAL WAVES...

TROPICAL WAVE NEARING THE LESSER ANTILLES ALONG 55W SOUTH OF 16N
MOVING WEST 20 KT. THIS WAVE CONTINUES TO DISPLAY A LARGE AND
IMPRESSIVE SIGNATURE IN SATELLITE IMAGERY WITH A SW/NE ELONGATED
CYCLONIC ENVELOPE BETWEEN 50W-60W. CONVECTION HAS ALSO INCREASED
WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION NOW COVERING
THE AREA FROM 10N-15N BETWEEN 52W-62W INCLUDING PORTIONS OF THE
WINDWARD ISLANDS AND TRINIDAD/TOBAGO.  THIS ACTIVITY WILL
CONTINUE TO SPREAD ACROSS THE ISLANDS TODAY AND TONIGHT
PRODUCING GUSTY WINDS AND LOCALLY HEAVY RAINFALL.

TROPICAL WAVE OVER THE E CARIBBEAN ALONG 65W MOVING W NEAR 15
KT.  THE HAS BEEN OVERTAKEN BY AN AFRICAN DUST SURGE WHICH IS
NOW CROSSING 70W.  DRY/STABLE AIR WITHIN THIS SURGE IS LIMITING
CONVECTION TO POINTS S OF 13. CURRENTLY...SCATTERED MODERATE
CONVECTION FROM 11N-13N BETWEEN 61W-67W.

TROPICAL WAVE OVER THE CENTRAL CARIBBEAN ALONG 76W SOUTH OF 15N
MOVING WEST NEAR 15 KT. THIS REMAINS LOCATED W OF AN UPPER LOW
NEAR 70W WHICH IS PRODUCING CONFLUENT FLOW AND SUBSIDENCE ACROSS
MUCH OF THE CENTRAL CARIBBEAN.  THIS IS RESTRICTING DEEP
CONVECTION TO POINTS S OF ABOUT 11N WITH SCATTERED MODERATE TO
STRONG CONVECTION NOW OVER PANAMA AND COSTA RICA SPREADING
WESTWARD INTO SE NICARAGUA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 14N10W 6N40W 5N50W 10N60W THEN
ACROSS N VENEZUELA AND COLOMBIA. SCATTERED STRONG CONVECTION OFF
THE SW COAST OF AFRICA WITHIN 125 NM EITHER SIDE OF ITCZ AXIS E
OF 20W. SIMILAR ACTIVITY WITHIN 300 NM N OF ITCZ AXIS W OF 52W
IN ASSOCIATION WITH A TROPICAL WAVE.

...DISCUSSION...

GULF OF MEXICO...
LARGE MIDDLE TO UPPER LEVEL CUTOFF LOW REMAINS PARKED OVER THE E
UNITED STATES NEAR THE CAROLINAS WITH A SHARP TROUGH TRAILING SW
OVER THE GLFMEX FROM THE FLORIDA PANHANDLE TO N MEXICO JUST S OF
THE TEXAS BORDER.  DEEP-LAYERED SW FLOW TO THE EAST OF THE
TROUGH IS ALLOWING A SIGNIFICANT PLUME OF TROPICAL MOISTURE TO
SURGE NWD ACROSS THE YUCATAN PENINSULA AND S HALF OF FLORIDA.
WATER VAPOR IMAGERY SHOWS THAT THE TROUGH AXIS HAS BEEN SLOWLY
RETREATING ALLOWING THIS MOISTURE TO CREEP NWD OVER FLORIDA.
THIS PATTERN IS PRODUCING WIDESPREAD CLOUDINESS AND
SHOWERS/TSTMS EQUATORWARD OF A LOW LEVEL TROUGH FROM LAKE
OKEECHOBEE TO THE BAY OF CAMPECHE.  THE LOW LEVEL TROUGH WILL
MOVE SLOWLY NWD OVER THE FLORIDA PENINSULA AND GLFMEX DURING THE
NEXT 2 DAYS WHILE THE UPPER LEVEL TROUGH IS FORECAST TO SHARPEN
OVER THE CENTRAL GLFMEX.  THIS WILL ALLOW MOISTURE TO CONTINUE
MOVING NWD AND PRODUCE A VERY WET AND STORMY PATTERN OVER THE SE
GLFMEX AND S TWO-THIRDS OF FLORIDA.  HEAVY RAINFALL WITH THIS
PATTERN WILL CREATE THE POTENTIAL FOR FLOODING ESPECIALLY OVER
ALREADY RAIN SOAKED PORTIONS OF FLORIDA.  ELSEWHERE...CONFLUENT
FLOW AND SUBSIDENCE ON THE POLEWARD SIDE OF THE UPPER TROUGH
AXIS SHOULD MAINTAIN VERY DRY/STABLE AIR ALOFT THROUGH
MID-WEEK.

CARIBBEAN SEA...
A RATHER ACTIVE PATTERN CONTINUES OVER THE CARIBBEAN WITH
SEVERAL AREAS OF ACTIVE CONVECTION.  THE FIRST AREA OF
CONVECTION IS LOCATED OVER THE NW CARIBBEAN AND YUCATAN
PENINSULA COURTESY OF A LOW LEVEL TROUGH OVER THE SE GLFMEX AND
A SHARP MIDDLE TO UPPER LEVEL TROUGH OVER THE CENTRAL GLFMEX.
THIS SETUP IS GENERATING SCATTERED TO LOCALLY NUMEROUS
THUNDERSTORMS WITHIN 100 NM EITHER SIDE OF A LINE FROM GUATEMALA
TO THE W TIP OF CUBA.  THIS ACTIVITY IS EXPECTED CONTINUE DURING
THE NEXT 12-12 HOURS PRODUCING LOCALLY HEAVY RAINFALL AND
POSSIBLE FLOODING PRIOR TO SLOWLY SPREADING INTO THE SE GLFMEX
BY TUE.  FURTHER E...THE MID-OCEANIC TROUGH HAS FRACTURED
FORMING A CUTOFF UPPER LOW WHICH IS RETROGRADING ACROSS THE
CENTRAL CARIBBEAN CURRENTLY NEAR 70W.  DIFFLUENCE E OF THIS
FEATURE IS PRODUCING INCREASING CLOUDINESS AND SHOWERS/TSTMS
OVER THE E CARIBBEAN ESPECIALLY S OF 13N. THIS ACTIVITY WILL
INCREASE AND EXPAND NWD AS A STRONG TROPICAL WAVE...CURRENTLY
ALONG 55W...MOVES INTO THE AREA WITHIN THE NEXT 12-24 HOURS.
FINALLY...A THIRD AREA OF ACTIVE CONVECTION IS LOCATED OVER THE
SW CARIBBEAN IN ASSOCIATION WITH A TROPICAL WAVE CURRENTLY ALONG
76W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS
LOCATED S OF 11N BETWEEN BETWEEN THE W COAST OF COLOMBIA TO
NICARAGUA. THIS ACTIVITY WILL SLOWLY MOVE WESTWARD AFFECTING
CENTRAL AMERICA MAINLY S OF THE HONDURAS/NICARAGUA BORDER.  ON
THE LARGER SCALE...THE ATLC SUBTROPICAL RIDGE CONTINUES TO
STRENGTHEN PRODUCING VERY STRONG ELY TRADES ACROSS A GOOD
PORTION OF THE CARIBBEAN.  RECENTLY INSTALLED NOAA BUOYS 42057
AND 42058 AS WELL AS A QUIKSCAT PASS FROM THIS MORNING INDICATE
WINDS ON THE ORDER OF 20-30 KT WITH GUSTS TO GALE FORCE.
ACCOMPANYING THIS HIGH WIND EVENT IS A LARGE AFRICAN DUST SURGE
WITH THE LEADING EDGE ESTIMATED ALONG 82W PER LATEST VISIBLE
SATELLITE IMAGERY.

ATLANTIC OCEAN...
THE SHARP MIDDLE TO UPPER LEVEL TROUGH-RIDGE-TROUGH PATTERN
CONTINUES OVER THE SUBTROPICAL ATLC WATERS WITH A HIGH AMPLITUDE
TROUGH OVER THE E UNITED STATES...BUILDING RIDGE OVER THE
CENTRAL TO W ATLC...AND THE MID-OCEANIC TROUGH ENTERING THE AREA
IN BETWEEN THE CANARY ISLANDS AND AZORES EXTENDING SW TO THE N
LEEWARD ISLANDS.  OVER THE DEEP TROPICAL ATLC...A WELL-DEFINED
E/W ORIENTED RIDGE REMAINS IN PLACE WITH MEAN AXIS ALONG
12N/13N.  RESULTING DEEP-LAYERED ELY FLOW S OF 10N E OF THE
LESSER ANTILLES.  THE BULK OF THE ACTIVE SHOWERS/TSTMS CONTINUE
TO BE FOCUSED OVER THE W ATLC IN ASSOCIATION WITH THE STRONG
TROUGH ALONG THE E UNITED STATES E COAST.  WIDESPREAD CLOUDINESS
AND SCATTERED SHOWERS/TSTMS CONTINUE OVER THE W ATLC WITHIN 150
NM EITHER SIDE OF A LINE FROM THE W TIP OF CUBA NEWD OVER S
FLORIDA TO BEYOND 31N75W INCLUDING THE N BAHAMAS.  THIS OVERALL
ACTIVITY WILL LIKELY PERSIST AND EXPAND SLOWLY NWD DURING THE
NEXT 12-24 HOURS AS THE UPPER TROUGH SHARPENS.  ANOTHER AREA OF
SIGNIFICANT CONVECTION IS LOCATED IN PROXIMITY OF A TROPICAL
WAVE NEARING THE LESSER ANTILLES. SEE TROPICAL WAVE DISCUSSION
ABOVE.  AT THE SURFACE...THE ATLC SUBTROPICAL RIDGE CONTINUES TO
STRENGTHEN FROM THE AZORES TO THE S BAHAMAS RESULTING IN
INCREASING TRADES OVER MUCH OF THE TROPICAL ATLC S OF 20N.  THIS
PATTERN IS FACILITATING THE WESTWARD PROGRESSION OF A LARGE AREA
OF AFRICAN DUST WHICH NOW SPANS FROM E CUBA TO AFRICA S OF 22N.

$$
RHOME


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