[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 101052
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUN 10 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1040 UTC.

...SPECIAL FEATURE...
1003 MB LOW IS IN THE NW CARIBBEAN AT 0900 UTC NEAR 20.5N85W
MOVING NW 5 KT.  SURFACE OBSERVATIONS INDICATE THE LOW HAS
PASSED BUOY 42056 AS IT REPORTED LIGHT SW WINDS AT 0700 UTC AND
A RATHER LOW PRESSURE.  NIGHT VIS IMAGES ARE SUGGESTING THAT A
LOW-LEVEL CENTER HAS EITHER MOVED NORTHWARD OR HAS REFORMED TO
THE W OF A LARGE BURST OF CONVECTION.  THE SYSTEM COULD BECOME A
TROPICAL DEPRESSION OR TROPICAL STORM AT ANY TIME.  COMPUTER
MODELS GENERALLY MOVE THE SYSTEM NORTHWESTERLY THRU THE YUCATAN
CHANNEL INTO THE SOUTHERN GULF OF MEXICO BY LATE TONIGHT.  AN
UPPER TROUGH TO THE W OF THE CYCLONE HAS BEEN GRADUALLY MOVING
WESTWARD WITH A LITTLE EXPANSION OF A UPPER ANTICYCLONE CENTERED
NEAR 18N83W.  HOWEVER VERTICAL WIND SHEAR IS MARGINAL FOR
DEVELOPMENT AS THE UPPER TROUGH IS STILL IMPARTING SW WINDS OVER
THE CIRCULATION CENTER.  FOR NOW.. THE PRIMARY THREAT IS
CONTINUED HEAVY RAINS OVER THE CAYMAN ISLANDS AND CENTRAL CUBA
WESTWARD AS SOME OF THOSE AREAS HAVE RECEIVED OVER 8 INCHES OF
RAIN.  SCATTERED BANDS OF TSTMS ARE MOSTLY TO THE E OF THE
SYSTEM WITH STRONG CONVECTION NOW FROM 18N-CUBA BETWEEN 80W-85W
AND MORE MODERATE CONVECTION FROM 17N-19N BETWEEN 81W-84W WITH A
FEW TSTMS REMAINING IN THE GULF OF HONDURAS.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 34W S OF 15N MOVING W 15-20 KT.  THIS IS
A LARGE WELL-DEFINED WAVE WITH A V-SHAPE IN BOTH THE LOW AND
MIDDLE LEVEL CLOUDS.  ISOLATED MODERATE CONVECTION IS S OF 8N
BETWEEN 34W-37W.

TROPICAL WAVE IS ALONG 59W S OF 9N MOVING W 10-15 KT.  ANY
SIGNIFICANT WEATHER WITH THE WAVE IS INLAND OVER NORTHERN S
AMERICA.  COMPUTER MODELS SUGGEST THAT MOISTURE WITH THE WAVE
SHOULD STAY S OF THE WINDWARD ISLANDS SAVE PERHAPS TRINIDAD.

TROPICAL WAVE IS ALONG 72W S OF 10N MOVING W 10-15 KT. WAVE IS
FAIRLY LOW-LATITUDE WITH NO SIGNIFICANT WEATHER OVER WATER.
SOME TSTMS OVER NW COLOMBIA ARE PROBABLY ASSOCIATED WITH THE
WAVE.

TROPICAL WAVE IS ALONG 82W/83W S OF 13N MOVING W 10 KT. THE
SOUTHERN EXTENSION OF THE WAVE IS PRODUCING SHOWERS/TSTMS OVER
COSTA RICA AND PANAMA.

ITCZ...
ITCZ AXIS IS CENTERED ALONG 10N14W 5N25W 8N35W 5N47W 7N58W.
SCATTERED MODERATE CONVECTION FROM 4N-6N BETWEEN 24W-28W.  A FEW
TSTMS ARE WITHIN 90 NM OF 9N20W.  WIDELY SCATTERED MODERATE
WITHIN 60 NM OF AXIS W OF 40W AND S OF AXIS BETWEEN 48W AND S
AMERICA.

...DISCUSSION...
GULF OF MEXICO...
UPPER RIDGING COVERS THE NORTHERN GULF WITH A CENTER JUST S OF
SE LOUISIANA.  ASSOCIATED WEAK SURFACE RIDGING IS ALONG 28N IN
THE GULF.. PROVIDING WLY WINDS AND RECORD HEAT TO PORTIONS OF
THE NORTHERN GULF COAST.  DEWPOINTS ARE CONSIDERABLY LOWER THAN
AVERAGE AS THE TYPICAL SUMMERTIME SLY LOW-LEVEL WINDS HAVEN'T
STARTED.  MODERATE/STRONG SUBSIDENCE IS CONTROLLING THE REGION N
AND W OF AN UPPER TROUGH EXTENDING FROM SW FLORIDA TO JUST W OF
THE YUCATAN PENINSULA.  THIS UPPER TROUGH IS MOVING SLOWLY
WESTWARD AS UPPER RIDGING POKES INTO THE SE GULF OF MEXICO.  AS
THE TROUGH SLIDES WESTWARD.. IT SHOULD ALLOW DEEP TROPICAL
MOISTURE IN ASSOCIATION WITH THE TROPICAL DISTURBANCE IN THE NW
CARIBBEAN TO SPREAD NORTHWARD... INCREASING THE THREAT OF RAIN
FOR S FLORIDA TODAY AND MUCH HIGHER FOR SUN...PERHAPS ALL OF
FLORIDA FOR MON.  THE NORTHERN GULF COAST W OF LOUISIANA LOOKS
QUITE DRY FOR THIS TIME OF THE YEAR THOUGH RAIN CHANCES MIGHT BE
ON THE INCREASE IN THE EASTERN GULF BY EARLY NEXT WEEK.

CARIBBEAN SEA...
THE MAIN WEATHER INTEREST IN THIS AREA IS A 1003 MB LOW IN THE
NW CARIBBEAN THAT IS PRODUCING WIDESPREAD CLOUDINESS AND SHOWERS
OVER THE REGION AND ADJACENT LAND AREAS. SEE SPECIAL FEATURE FOR
DETAILS.  UPPER RIDGE AXIS EXTENDS FROM NEAR JAMAICA EASTWARD TO
JUST N OF PUERTO RICO WITH ELY WINDS ALOFT OVER THE CARIBBEAN
SAVE FOR A SMALL AREA OF UPPER TROUGHING IN THE FAR SE WINDWARD
ISLANDS.  LOW-LEVEL CONVERGENCE BETWEEN THE SLY FLOW FROM THE
TROPICAL SYSTEM AND ELY FLOW FROM THE ATLC RIDGE IS ENHANCING
SCATTERED MODERATE CONVECTION NW OF COLOMBIA FROM 9.5N-12.5N
BETWEEN 76W-79W.  ELSEWHERE UPPER CONVERGENCE IS LEADING TO A
DRY WEATHER PATTERN OVER THE EASTERN CARIBBEAN.  THE GFS
INCREASES THE DEEP-LAYERED MOISTURE SOME IN THE NE CARIBBEAN BY
LATE SUN WHICH COULD PROVOKE A FEW MORE SHOWERS/TSTMS IN THAT
AREA.  NEXT SIGNIFICANT WAVE IS FORECAST TO ENTER THE E
CARIBBEAN EARLY TUE AND MIGHT BE THE MOST CONVECTIVELY-ACTIVE OF
THE SEASON SO FAR.

ATLANTIC OCEAN...
UPPER TROUGH NOSES INTO THE NW PART OF THE AREA ALONG 68W N OF
27N INCREASING THE NUMBER OF MID/UPPER CLOUDS N OF 27N ALONG
WITH A FEW SHOWERS.  LARGE MID-OCEANIC TROUGH IS SITTING FROM
31N41W 14N50W THEN INTO THE WINDWARD ISLANDS NEAR BARBADOS WITH
A MID/UPPER LOW NEAR 26N45W ALONG THE TROUGH.  MODERATE/STRONG
SUBSIDENCE CONTROLS MUCH OF THE REGION WITHIN ABOUT 300 NM OF
THE TROUGH EXCEPT FOR ISOLATED SHOWERS/TSTMS WITHIN 120 NM OF
THE LOW CENTER... WHICH HAS A WEAK SURFACE TROUGH REFLECTION.
IN THE E ATLC.. HIGH PRESSURE HAS BUILT UP IN THE MID/UPPER
LEVELS WITH A CENTER NEAR 19N24W.. MUCH FARTHER N THAN AVERAGE
FOR EARLY JUNE.  RIDGE AXIS EXTENDS TO 19N33W 9N40W 7N60W..
FARTHER S THAN AVERAGE IN THE CENTRAL ATLC.  THIS UPPER PATTERN
IS FAVORABLE TO SUPPORT A FAIR NUMBER OF TSTMS IN THE ITCZ AND
SOMEWHAT CONVECTIVE WAVES.  TYPICAL STRATOCUMULUS DECK COVERS
THE CENTRAL/E ATLC WITH THE SUBTROPICAL RIDGE IN CONTROL..
ALBEIT A TAD WEAKER THAN AVERAGE.  COMPUTER MODELS SUGGEST THAT
THE NEXT FEW WAVES WILL BE FAIRLY STRONG WITH A MUCH FARTHER
NORTHWARD EXTENT THAN THE RECENT BATCH W OF 50W.  THIS IS
POSSIBLY DUE TO A LARGE-SCALE DIVERGENCE PATTERN ... SOMEWHAT
RELATED TO THE MADDEN-JULIAN OSCILLATION ... BEING OVERHEAD FOR
THE NEXT WEEK OR SO.

$$
BLAKE


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