[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 031747
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN JUL 03 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.

...SPECIAL FEATURES...
W CARIBBEAN TROPICAL WAVE EXTENDS FROM THE YUCATAN CHANNEL INTO
NW HONDURAS WITH A 1010 MB LOW NEAR 19N86W MOVING WNW 10 KT.
THE LOW CONTINUES TO GET BETTER ORGANIZED WITH BANDING FEATURES
BECOMING MORE PROMINENT IN THE SOUTHERN SEMICIRCLE AND A LARGE
ANTICYCLONE ALOFT PROVIDING A FAVORABLE ENVIRONMENT FOR FURTHER
DEVELOPMENT.  BUOY 42056 JUST REPORTED A SUSTAINED WIND OF 31 KT
TO THE NE OF THE CENTER.  A LARGE AREA OF TSTMS HAS DIED DOWN
SOMEWHAT IN THE PAST 3 HOURS BUT WIDELY SCATTERED MODERATE
CONVECTION REMAINS OVER THE NW CARIBBEAN N OF 16N W OF 80W WITH
HEAVY RAINS MOVING OVER W CUBA AND THE ISLE OF PINES.  THIS
SYSTEM IS LIKELY TO MOVE OVER YUCATAN OVERNIGHT AND BRING VERY
HEAVY RAIN... EMERGING INTO THE GULF OF MEXICO LATE MON/EARLY
TUE.  THIS LOW HAS THE POTENTIAL TO BECOME A TROPICAL CYCLONE
WITHIN THE NEXT DAY OR TWO.

...TROPICAL WAVES...
E-CENTRAL TROPICAL WAVE ALONG 36W S OF 15N MOVING W 10 TO 15
KT.  THIS WAVE IS THE LEAST WELL-DEFINED IN THE BASIN AS THERE
IS ONLY WEAK TURNING OBSERVED IN THE LOW CLOUDS N OF THE WAVE
AND A SMALL NORTHWARD PROTRUSION OF THE ITCZ.  THE MID-LEVEL
WINDS FROM THE GFS/UKMET ALSO SUPPORT THIS WAVE POSITION. WIDELY
SCATTERED MODERATE CONVECTION WITHIN 75 NM OF 9N37.5W.  THE GFS
SUGGESTS THIS WAVE COULD IMPACT THE WINDWARD ISLANDS LATE THU.

STRONG W ATLC TROPICAL WAVE IS TILTED FROM E GUYANA TO 17N50W
WITH A BROAD 1013 MB LOW ALONG THE WAVE NEAR 11N55W AS THE WHOLE
SYSTEM MOVES W 15 KT.  THIS WAVE HAS GOTTEN BETTER-ORGANIZED
OVERNIGHT WITH NE TO NW WINDS OBSERVED IN THE WINDWARD ISLANDS S
OF BARBADOS AND SLY WINDS OVER GUYANA EASTWARD THRU FRENCH
GUIANA.  SOME BANDING-TYPE FEATURES ARE TRYING TO FORM W OF THE
WAVE AXIS THOUGH HIGH RESOLUTION VISIBLE IMAGES ARE NOT SHOWING
ANY CLOSED CIRCULATION WINDS.  REGARDLESS OF DEVELOPMENT...
SHOWERS AND TSTMS WITH GUSTY WINDS ARE OVERSPREADING THE
WINDWARD ISLANDS WITH STORMY WEATHER FORECAST FOR AT LEAST THE
PART FEW DAYS OF THE WEEK DUE TO THE LARGE SIZE AND MOISTURE
ENVELOPE OF THE WAVE.  SCATTERED TSTMS COVER THE AREA FROM
9N-14N BETWEEN 54W-61W WITH MORE WIDELY SCATTERED ACTIVITY FROM
8N-15N BETWEEN 45W-54W.

W TROPICAL ATLC WAVE DISCUSSED IN THE SPECIAL FEATURE SECTION.

...ITCZ...

ITCZ AXIS IS ALONG 12N17W 8N26W 10N36W 8N42W 11N60W.  ISOLATED
MODERATE CONVECTION FROM 6N-10N BETWEEN 29W-45W.  SCATTERED
MODERATE FROM 8N-12N BETWEEN 45W-60W.  SIMILAR CONVECTION IS
FROM 9.5N-14N BETWEEN W AFRICA AND 22W... ASSOCIATED WITH THE
NEXT WAVE JUST LEAVING THE COAST.

...DISCUSSION...

GULF OF MEXICO...
THOUGH THE GULF IS MOSTLY CLEAR...THE TROPICS ARE EXCEPTIONALLY
ACTIVE FOR 4TH OF JULY WEEKEND.   SHOWERS AND TSTMS FROM THE NW
CARIBBEAN DISTURBANCE ARE MOVING INTO THE EXTREME SE GULF NEAR
THE YUCATAN CHANNEL.  MOISTURE ASSOCIATED WITH THIS SHOULD
SLOWLY MOVE NWWD TOWARD THE CENTRAL GULF COAST FOR MIDWEEK.  FOR
NOW MOST OF THE AREA N OF 25N HAS PARTLY CLOUDY SKIES WITH
MODERATE SUBSIDENCE ALOFT.  A TRIO OF WEAK MID/UPPER LOWS ARE IN
THE WESTERN GULF... JUST SE OF GALVESTON AND THE OTHER TWO NEAR
20N97W/24N92.5W.  THESE FEATURES SHOULD MOVE OUT OF THE WAY AS A
LARGE ANTICYCLONE FROM THE CARIBBEAN HEADS NWWD.  CONDITIONS
COULD DRY OUT A BIT FOR THE FLORIDA PENINSULA AS MOST OF THE
MOISTURE ASSOCIATED WITH THE TROPICAL SYSTEM IS FORECAST TO MOVE
W OF THE AREA AND LEAVE UPPER RIDGING IN ITS WAKE TO SUPPRESS
CONVECTION A BIT.

CARIBBEAN SEA...
THE CENTRAL CARIBBEAN IS SANDWICHED BETWEEN THE WAVE IN THE NW
CARIBBEAN AND THE WAVE APPROACHING THE WINDWARD ISLANDS.
OTHERWISE DRY AIR IN THE MID/UPPER LEVELS DOMINATES BETWEEN
65W-80W WITH A SMALL AREA OF TSTMS JUST S OF DOMINICAN REPUBLIC
NEAR 17N70W.  ELY WINDS BASICALLY COVER THE CARIBBEAN WITH MUCH
LESS-THAN-AVERAGE SHEAR THROUGHOUT THE AREA.  WET WEATHER SHOULD
BE MOVING INTO PUERTO RICO BY LATE MON AND INTO THE WHOLE
CARIBBEAN E OF 70W BY TUE.

ATLANTIC OCEAN...
UPPER RIDGING CONTROLS THE W ATLC WITH WIDELY SCATTERED MODERATE
CONVECTION WITHIN 90 NM OF 31N75W AHEAD OF A STATIONARY FRONT.
ANY SIGN OF THE MID-OCEANIC TROUGH HAS SHIFTED WELL TO THE N
FROM 20N63W TO 31N60W WITH INSTABILITY ALONG THE TROUGH AXIS
FIRING A FEW TSTMS FROM 25N-31N BETWEEN 55W-60W.  BROAD
TROUGHING COVERS THE CENTRAL ATLC N OF 20N W OF 30W WITH A
SHORTWAVE NEAR 31N49W RESPONSIBLE FOR ISOLATED TSTMS.  YET
ANOTHER TROUGH DIPS INTO THE FAR NE ATLC NEAR THE CANARY ISLANDS
BUT IS VIRTUALLY WEATHER-LESS DUE TO VERY DRY AIR.  FARTHER
S...THE DEEP TROPICS ARE CONTROLLED BY ANTICYCLONIC FLOW WITH
RIDGING FROM W MAURITANIA TO THE SOUTHERN LEEWARD ISLANDS.
DIFFLUENT FLOW TOWARD THE WESTERN END OF THIS RIDGE IS HELPING
TO SPARK TSTMS AS A TROPICAL WAVE APPROACHES THE LESSER
ANTILLES.  MODERATE/STRONG SUBSIDENCE IS N OF OF THE RIDGE AXIS
TO 25N WITH SOME SAHARAN DUST MIXED IN E OF 50W.  AT THE
SURFACE... LARGE 1033 MB HIGH NEAR 38N38W DOMINATES THE AREA
EXCEPT FOR TROPICAL WAVES ALONG ITS SOUTHERN PERIPHERY.

$$
BLAKE

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