[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211759
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON JUN 21 2010

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC...

...SPECIAL FEATURES...

TROPICAL WAVE EXTENDS FROM PUERTO RICO NEAR 19N66W TO 08N67W
MOVING W 10 KT. THE WAVE COINCIDES WITH A BROAD AREA OF DEEP
LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY
ACROSS THE EASTERN CARIBBEAN SEA BETWEEN 64W-74W. BROAD CYCLONIC
FLOW IS LOCATED IN THE VICINITY OF THE WAVE INDICATED BY
SATELLITE IMAGERY AND AN EARLIER ASCAT PASS AROUND 21/1438 UTC.
NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS FROM
10N-18N BETWEEN 64W-70W.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 15N24W TO 06N27W MOVING W 10-15 KT. A
DRY MIDDLE TO LOW-LEVEL VORTICITY CENTER IS AHEAD OF THE WAVE
AND EXHIBITS CYCLONIC TURNING OF THE MIDDLE TO LOW-LEVEL CLOUD
FIELD...WITH AN EARLIER MORNING WINDSAT AND ASCAT PASS AROUND
0802 UTC AND 1116 UTC RESPECTIVELY INDICATING A SWATH OF NE
WINDS TO THE NORTH OF THE WAVE. METEOSAT-9 VISIBLE SATELLITE
IMAGERY ALSO INDICATES A LARGE AREA OF DUST ASSOCIATED WITH THE
WAVE FROM 10N-22N E OF 43W. WIDELY SCATTERED MODERATE CONVECTION
IS FROM 05N-10N BETWEEN 23W-31W. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION IS LOCATED SE OF THE WAVE AXIS FROM 04N-09N
BETWEEN 16W-23W AND MOST LIKELY MORE ASSOCIATED WITH UPPER LEVEL
DIFFLUENCE LOCATED OVER THE EASTERN TROPICAL ATLC.

TROPICAL WAVE EXTENDS ALONG 12N54W TO 02N56W MOVING W 10-15 KT.
TOTAL PRECIPITABLE WATER IMAGERY HAS BEEN PROVIDING THE BEST
INDICATIONS FOR THE LOCATION OF THE WAVE DUE TO ONGOING
CONVECTION AND PLENTY OF MIDDLE AND HIGH LEVEL CLOUDINESS. THE
WAVE IS POSITIONED LARGELY ON A MAXIMUM IN TPW BETWEEN 52W-56W.
GLOBAL MODEL GUIDANCE ALSO INDICATES LOW-LEVEL CYCLONIC FLOW IN
STREAMLINE CONTOURS AND THE POTENTIAL VORTICITY FIELDS.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM
07N-12N BETWEEN 52W-59W.

TROPICAL WAVE EXTENDS FROM THE FLORIDA STRAITS NEAR 24N80W
ACROSS CENTRAL CUBA TO 17N78W TO 14N78W MOVING W AT 10-15 KT.
THE WAVE APPEARS TO BE FRACTURING ENERGY TO THE NW WITH
SCATTERED MODERATE CONVECTION FROM 19N-25N BETWEEN 79W-84W.
VISIBLE SATELLITE IMAGERY SHOWS THE WAVE AXIS FARTHER EAST
ACROSS PORTIONS OF THE CARIBBEAN IN AN AREA OF LOW-LEVEL
CYCLONIC TURNING OF THE LOW-LEVEL CLOUD FIELD. SCATTERED
MODERATE CONVECTION IS FROM 14N-18N BETWEEN 75W-80W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 12N17W 13N22W 07N28W 06N42W 08N54W.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 120
NM OF THE AXIS BETWEEN 16W-20W. A SURFACE TROUGH IS EMBEDDED
WITHIN THE AXIS ALONG 42W S OF 10N. CYCLONIC CURVATURE OF THE
LOW-LEVEL CLOUD FIELD IS NOTED WITH THE SURFACE TROUGH WHICH IS
GENERATING SCATTERED MODERATE AND ISOLATED STRONG CONVECTION
FROM 04N-10N BETWEEN 39W-46W. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION STRETCHING W-NW FROM THE SURFACE TROUGH WITHIN
250 NM NORTH OF THE AXIS BETWEEN 46W-52W.

...DISCUSSION...

GULF OF MEXICO...
A WEAK UPPER LEVEL SHORTWAVE TROUGH EXTENDS ALONG THE EASTERN
U.S. SEABOARD AND SUPPORT A SURFACE TROUGH FROM SOUTHERN GEORGIA
NEAR 31N83W INTO THE CENTRAL GULF WATERS NEAR 26N89W. MOSAIC
DOPPLER RADAR AND LIGHTNING DATA INDICATE SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING N OF 27N E OF 91W. FARTHER
SE...ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF 25N E OF
84W...INCLUDING THE FLORIDA STRAITS...DUE TO THE W-NW ADVANCE OF
A TROPICAL WAVE ALONG 80W AND CENTRAL CUBA. ENERGY FROM THIS
TROPICAL WAVE IS FORECAST TO CONTINUE TRACKING W-NW AND BECOME
ABSORBED BY THE UPPER LEVEL SHORTWAVE TROUGH AND SURFACE TROUGH
OVER THE NE GULF. ELSEWHERE...A WEAK PRESSURE GRADIENT EXISTS
ACROSS THE BASIN AND IS CONTRIBUTING TO LIGHT E-SE WINDS AND
GENERALLY FAIR SKIES. ALOFT...AN UPPER LEVEL RIDGE IS CENTERED
OVER SOUTHERN TEXAS AND PROVIDES MODERATELY DRY NE UPPER LEVEL
FLOW.

CARIBBEAN SEA...
A PAIR OF WELL DEFINED TROPICAL WAVES ARE MOVING ACROSS THE
CARIBBEAN SEA BASIN. THE TROPICAL WAVE MOVING ACROSS THE EASTERN
CARIBBEAN SEA FALLS BENEATH AN UPPER LEVEL DIFFLUENT ENVIRONMENT
ON THE WESTERN PERIPHERY OF AN ANTICYCLONIC CIRCULATION CENTERED
IN THE TROPICAL NORTH ATLC NEAR 13N59W IN THE VICINITY OF
BARBADOS. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS
ASSOCIATED WITH THE WAVE FROM 10N-18N BETWEEN 64W-70W WITH
SCATTERED SHOWERS COVERING THE REMAINDER OF THE AREA EASTERN
CARIBBEAN BETWEEN 61W-73W. THE OTHER TROPICAL WAVE EXTENDS FROM
CENTRAL CUBA TO THE WEST OF JAMAICA NEAR 18N79W TO 14N78W. THIS
WAVE IS LOCATED BENEATH AN UPPER LEVEL LOW CENTERED OVER THE
CENTRAL BAHAMAS NEAR 23N76W WITH AN UPPER LEVEL TROUGH AXIS
EXTENDING SW TO THE YUCATAN PENINSULA NEAR 20N88W. LOW-LEVEL
CONVERGENCE AND INSTABILITY ASSOCIATED WITH THE WAVE COUPLED
WITH UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL TROUGH AXIS
IS GENERATING A SCATTERED SHOWERS AND TSTMS WITHIN 60 NM OF A
LINE FROM 19N78W TO 22N84W. THE SOUTHERN EXTENT OF THE TROPICAL
WAVE FALLS BENEATH AN UPPER LEVEL RIDGE AXIS EXTENDING FROM
SOUTHERN MEXICO ACROSS GUATEMALA TO NEAR 14N78W. AN UPPER LEVEL
DIFFLUENT PATTERN EXISTS ACROSS THE SW CARIBBEAN AND IS
GENERATING SCATTERED SHOWERS AND TSTMS S OF 18N BETWEEN 74W-86W.

ATLANTIC OCEAN...
AN UPPER LEVEL SHORTWAVE TROUGH AXIS EXTENDS ACROSS THE EASTERN
U.S. SEABOARD AND ALONG WITH LOW-LEVEL CONVERGENCE OVER PORTIONS
OF THE W ATLC...CONTINUES TO GENERATE ISOLATED SHOWERS AND TSTMS
N OF 29N BETWEEN 75W-81W. AN UPPER LEVEL LOW IS CENTERED NEAR
23N76W OVER THE CENTRAL BAHAMAS AND IS PROVIDING DRY AIR ALOFT
AND GENERALLY FAIR SKIES N OF 21N W OF 70W AND N OF 24N BETWEEN
60W-70W. UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL LOW IS
ADVECTING MOISTURE AND CLOUDINESS NE FROM THE NORTHERN EXTENT OF
THE TROPICAL WAVE LOCATED IN THE EASTERN CARIBBEAN. BROAD
CYCLONIC TURNING OF THE LOW-LEVEL CLOUDS ACROSS THE W ATLC IS
EVIDENT ON SATELLITE IMAGERY WITH POSSIBLE ISOLATED SHOWERS FROM
18N-24N BETWEEN 50W-70W. FARTHER EAST...SURFACE RIDGING
DOMINATES ANCHORED BY A 1029 MB HIGH CENTERED NEAR 33N32W
PROVIDING GENERALLY FAIR WEATHER ACROSS THE CENTRAL AND EASTERN
ATLC. A DRY SAHARAN AIR LAYER WRAPS AROUND THE TROPICAL WAVE
POSITIONED FROM THE CAPE VERDE ISLANDS SOUTHWARD TO 06N27W. THE
AFRICAN DUST IS NOTED ON METEOSAT-9 VISIBLE IMAGERY FROM 10N-22N
E OF 43W TO THE W AFRICA COAST. ALOFT...AN UPPER LEVEL TROUGH
AXIS EXTENDS FROM 29N33W TO 18N45W EMBEDDED BETWEEN TWO UPPER
LEVEL ANTICYCLONIC CIRCULATIONS CENTERED NEAR 13N34W AND 13N59W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
HUFFMAN



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