[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 311802
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE MAY 31 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 ADDED ALONG 29W S OF 12N MOVING W 20 KT.  THE
DAKAR TIMESECTION SHOWS THE WAVE PASSING BEFORE 12 UTC ON THE
29TH WITH SATELLITE SUPPORTING THAT POSITION.  TSTMS ARE ALSO
QUITE ACTIVE WITH WIDELY SCATTERED MODERATE CONVECTION FROM
4N-9N BETWEEN 23W-37W.

CENTRAL ATLC TROPICAL WAVE ALONG 47W S OF 12N MOVING W 20 KT.
WAVE REMAINS EMBEDDED WITHIN A LARGE SWATH OF AFRICAN DUST WITH
ENHANCED ELY TRADEWINDS ALSO ACTING TO SUPPRESS THE WAVE'S
SIGNATURE.  SCATTERED MODERATE CONVECTION IS WITHIN THE ITCZ
FROM 6N-9N BETWEEN 47W-51W.  MOISTURE FROM THE WAVE WILL BEGIN
TO ENTER THE SE CARIBBEAN BY LATE WED BRINGING A GREATER-
THAN-AVERAGE CHANCE OF SHOWERS S OF GUADELOUPE THRU THU.

TROPICAL WAVE OVER THE CENTRAL CARIBBEAN ALONG 76W S OF 20N
MOVING W 15-20 KT.   WAVE POSITION IS BASED ON EXTRAPOLATION
WITH LITTLE SATELLITE PRESENTATION.

TROPICAL WAVE OVER CENTRAL AMERICA ALONG 88W/89W S OF 18N MOVING
W 10-15 KT. MOST OF THE ENERGY WITH THIS WAVE IS S OF THE AREA
OVER THE EPAC WITH NO ASSOCIATED DEEP CONVECTION IN THE AREA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N14W 6N21W 8N45W 7N60W.  WIDELY
SCATTERED MODERATE W OF 55W S OF 9N AND FROM 6N-9N BETWEEN
38W-46W.  SCATTERED MODERATE FROM 3.5N-8N BETWEEN 20W-27W.

...DISCUSSION...

GULF OF MEXICO...
INTERESTING WEATHER PATTERN FOR LATE MAY WITH A STATIONARY FRONT
ALONG THE FL/GA BORDER WSW INTO A 1006 MB LOW JUST SOUTH OF
BILOXI WITH THE FRONT DISSIPATING WSW ACROSS SE LOUISIANA THRU
THE NW GULF TO 28N94W.  MID/UPPER LOW NEAR 27N91W WAS
RESPONSIBLE FOR INITIATING A STRONG SQUALL LINE THAT PROPAGATED
EASTWARD AND HAS CLEARED THE FLORIDA PENINSULA... LEAVING COOLER
TEMPERATURES AND MOSTLY CLOUDY SKIES IN ITS WAKE.  ANOTHER ROUND
OF TSTMS IS FORMING IN A STRONGLY DIFFLUENT REGION E OF THE
FLORIDA ALONG 25N88W TO 30N85W BUT ITS MOVEMENT APPEARS TO BE
MORE NORTHEASTERLY TOWARD THE FLORIDA PANHANDLE.  MOSTLY CLEAR
SKIES ARE BEHIND THE MID/UPPER TROUGH IN THE WESTERN GULF UNDER
STRONG SUBSIDENCE.  ONLY A SLOW EASTWARD PROGRESS IS EXPECTED
WITH THIS SYSTEM.. LEAVING N FLORIDA AND THE PANHANDLE IN A WET
PATTERN FOR THE NEXT FEW DAYS.

CARIBBEAN...
A WELL-DEFINED MID/UPPER LEVEL HIGH IS CENTERED OVER THE SW
WITH A MID/UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL ATLC
INTO THE E CARIBBEAN E OF 71W. THIS PATTERN CONTINUES TO PRODUCE
SUBSIDENCE AND DRY/STABLE AIR ALOFT OVER THE CENTRAL TO W
CARIBBEAN FROM 74W-82W AND IS MAKING TROPICAL WAVES DIFFICULT TO
FIND.  HOWEVER ITCZ ACTIVITY IS ENHANCED DUE TO DIFFLUENT FLOW
IN THE FAR SW CARIBBEAN WITH WIDELY SCATTERED TSTMS S OF SAN
ANDRES W OF 80W.  FURTHER W...DEEP-LAYERED S FLOW AND ASSOCIATED
MOISTURE ADVECTION AHEAD OF A TROUGH OVER THE W GULF WILL
PRODUCE ENHANCED AFTERNOON SHOWERS/THUNDERSTORMS OVER THE
YUCATAN PENINSULA INTO THE NW CARIBBEAN.  HAZY SKIES CONTINUE
OVER MOST OF THE CARIBBEAN E OF 75W WITH AFRICAN DUST BEING THE
CAUSE.  WET WEATHER SHOULD SHIFT WESTWARD BY LATE-WEEK WITH
MOISTURE FROM THE CENTRAL CARIBBEAN TROPICAL WAVE INTERACTING
WITH AN UPPER TROUGH OVER THE GULF.. LEADING TO POSSIBLY HEAVY
RAINS OVER W CUBA.. HONDURAS AND NICARAGUA.

ATLANTIC...
UPPER LEVEL RIDGING COVERS THE AREA W OF 70W COMING FROM THE W
CARIBBEAN.  WIDELY SCATTERED TSTMS ARE N OF 27N W OF 75W.. A
REMNANT OF A SQUALL LINE FROM THE GULF OF MEXICO OVERNIGHT.
OTHERWISE A COLD FRONT IS RIGHT ALONG THE BORDER NEAR 31NW
BEFORE 73W-79W WITH ISOLATED TSTMS NEAR THE BOUNDARY.   THE FAR
NW PART OF THE AREA IS LIKELY TO CONTINUE TO BE CONVECTIVELY-
ACTIVE WITH THE FRONT NEARBY ALONG WITH UPPER ENERGY FROM THE
GULF OF MEXICO.   DOWNSTREAM OF THE RIDGE... BROAD BUT WEAK
TROUGHING FROM THE CENTRAL ATLC COVERS THE AREA FROM 26W-65W
SAVE A WEAK UPPER HIGH NEAR 28N41W.  OTHERWISE THE TROUGH IS
COMPRISED OF A SERIES OF SHORTWAVE FEATURES WITH A TROUGH FROM
30N32W TO THE E LEEWARD ISLANDS....AN EMBEDDED UPPER LOW NEAR
19N43W AND A  LOW NEAR 31N26W.  UPPER TROUGH NEAR THE LEEWARD
ISLANDS IS ENHANCING ITCZ CONVECTION WITH WESTERLIES OVER DEEP
MOIST ELY FLOW.  OTHERWISE MODERATE SUBSIDENCE COVERS THE
TROPICAL ATLC W OF 30W WITH STRONG ZONAL FLOW ALOFT.  IN THE E
ATLC... MID/UPPER RIDGING IS GROWING ALONG 18W NEAR THE W COAST
OF AFRICA WITH UPPER DIFFLUENCE SUPPORTING WIDELY SCATTERED
TSTMS IN THE ITCZ E OF 35W.  AT THE SURFACE... THE HIGHEST
PRESSURES IN QUITE SOME TIME ARE SUPPORTING 20 TO OCCASIONALLY
25 KT TRADES S OF 20N W OF THE CAPE VERDES FROM A DISTANT 1031
MB AZORES HIGH.  MODELS SUGGEST THIS HIGH WILL WEAKEN WITH TIME
AS A COLD FRONT JUST N OF THE AREA ALONG 51W IS REINFORCED BY A
STRONGER FRONT... PUSHING SE INTO THE SUBTROPICAL RIDGE AND
RELAXING THE PRESSURE GRADIENT FOR THE WEEKEND.  FOR NOW...S OF
THE RIDGE THE MODERATE TO STRONG TRADES PREVAIL WITH AN
EXPANSIVE PLUME OF AFRICAN DUST SPANNING THE ENTIRE LENGTH OF
THE ATLC AND CARIBBEAN...GENERALLY S OF 25N TO THE ITCZ.

$$
BLAKE

WWWW
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