[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211754
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN JUN 21 2015

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

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

...SPECIAL FEATURES...

A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE ACROSS THE
WESTERN ATLC AND THE GULF OF MEXICO...AND A 1006 MB LOW OVER
NORTHERN COLOMBIA SUPPORTS NEAR GALE FORCE WINDS OVER A PORTION
OF THE SOUTH-CENTRAL CARIBBEAN TODAY. THE GRADIENT WILL TIGHTEN
FURTHER TONIGHT...WHICH WILL RESULT IN GALE FORCE WINDS STARTING
AT 0600 UTC TONIGHT FROM 11N TO 14N BETWEEN 72W AND 77W. SEAS OF
10 TO 14 FT ARE EXPECTED. THESE GALE FORCE WINDS ARE FORECAST TO
PERSIST UNTIL 1200 UTC MONDAY. PLEASE READ THE HIGH SEAS
FORECAST... MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE
FORECAST...MIAOFFNT3/ FZNT23 KNHC...FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE EASTERN TROPICAL ATLC WITH AXIS
ALONG 20N FROM 16N TO 06N...MOVING W AT AROUND 15 TO 20 KT.
SSMI TPW IMAGERY INDICATE THIS WAVE IS EMBEDDED IN A MODERATE
MOIST ENVIRONMENT S OF 15N WITH METEOSAT IMAGERY INDICATING
SAHARAN DUST AND DRY AIR N OF 15N. SCATTERED MODERATE CONVECTION
IS FROM 07N TO 12N BETWEEN THE AFRICAN COAST AND 21W.

A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLC WITH AXIS
ALONG 40W/41W FROM 12N TO 04N...MOVING W AT 20 KT OVER THE PAST
24 HOURS. SSMI TPW IMAGERY SHOWS THE WAVE IS EMBEDDED IN A
MODERATE MOIST ENVIRONMENT S OF 12N...EXCEPT IN THE NORTHERN
REGION WHERE METEOSAT SATELLITE IMAGERY INDICATES SAHARAN DRY
AIR AND DUST. NO DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS
TIME.

A TROPICAL WAVE IS IN THE WESTERN TROPICAL ATLC EXTENDING FROM
16N54W TO S AMERICA NEAR 05N57W...MOVING W AT 15 KT OVER THE
PAST 24 HOURS. SSMI TPW IMAGERY INDICATES THAT THIS WAVE IS
EMBEDDED IN A DEEP MOIST AIRMASS. STRONG WESTERLY SHEAR IS
CURRENTLY IMPACTING THIS WAVE. CLUSTERS OF MODERATE CONVECTION
ARE FROM 08N TO 15N BETWEEN 51W AND 63W.

A TROPICAL WAVE IS IN THE SW CARIBBEAN BASIN WITH AN AXIS ALONG
82W FROM 17N TO PANAMA TO THE EASTERN PACIFIC...MOVING W NEAR 10
KT OVER THE PAST 24 HOURS. SSMI TPW IMAGERY INDICATES THAT THERE
IS ABUNDANT MOISTURE S OF 12N ALONG THE WAVE...WITH DRY AIR N OF
12N. SCATTERED MODERATE TO STRONG CONVECTION ARE FROM 09N TO 11N
BETWEEN 81W AND 85W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO 17N16W...THEN
RESUMES W OF A TROPICAL WAVE NEAR 08N21W AND CONTINUES TO
06N33W. THE ITCZ BEGINS NEAR 06N43W AND CONTINUES TO E OF A
TROPICAL WAVE NEAR 05N55W. BESIDES THE CONVECTION ASSOCIATED
WITH THE TROPICAL WAVES...ISOLATED MODERATE CONVECTION IS WITHIN
100 NM OF EITHER SIDE OF THE MONSOON TROUGH BETWEEN 21W AND 30W.

...DISCUSSION...

THE GULF OF MEXICO...

AN ELONGATED UPPER TROUGH EXTENDS FROM CENTRAL FL SOUTHWESTWARD
TO THE YUCATAN PENINSULA. AN UPPER RIDGE IS OVER CENTRAL MEXICO.
AREAS OF WEAK UPPER LEVEL DIFFLUENCE OVER THE SW...SE...AND NE
GULF SUPPORTS SCATTERED MODERATE CONVECTION WITHIN 50 NM OF THE
MEXICO COAST FROM 26N TO 20N...SCATTERED THUNDERSTORMS FROM 22N
TO 25N BETWEEN 81W AND 86W...AND FROM 29N TO THE GULF COAST
BETWEEN 84W AND 89W. SURFACE RIDGING EXTENDS FROM THE WESTERN
ATLC TO THE NORTHERN GULF AND IS ANCHORED BY A 1020 MB HIGH
CENTERED OVER THE NE GULF NEAR 27N86W. ANTICYCLONIC FLOW
GENERALLY UNDER 10 KT IS OVER THE EASTERN GULF...WHILE
SOUTHEASTERLY WINDS AROUND 15 KT ARE OVER THE WESTERN GULF. A
SURFACE TROUGH EXTENDS FROM 24N91W TO 18N93W. NO CONVECTION IS
ASSOCIATED WITH THIS TROUGH. OVER THE NEXT 24 HOURS EXPECT
CONVECTION TO CONTINUE TO BE POSSIBLE OVER THE SW GULF.

THE CARIBBEAN SEA...

A TROPICAL WAVE IS OVER THE SW CARIBBEAN. PLEASE SEE THE SPECIAL
FEATURES SECTION FOR MORE DETAILS. A TIGHT PRESSURE GRADIENT
BETWEEN HIGH PRESSURE OVER THE WESTERN ATLC AND GULF OF MEXICO
AND LOW PRESSURE OVER N COLOMBIA SUPPORTS NEAR GALE-FORCE WINDS
OVER A PORTION OF THE SOUTH-CENTRAL CARIBBEAN. PLEASE SEE THE
SPECIAL FEATURES SECTION FOR MORE DETAILS. MODERATE MOISTURE IS
CONFINED ALONG THE GREATER ANTILLES WITH RELATIVELY DRY AIR OVER
THE CARIBBEAN BETWEEN 12N AND 17N. OTHER THAN CONVECTION
ASSOCIATED WITH THE WAVE OVER THE SW BASIN...SCATTERED
THUNDERSTORMS ARE FROM 21N TO 22N BETWEEN 82W AND 85W...AND OVER
THE SOUTHERN LESSER ANTILLES WELL IN ADVANCE OF A TROPICAL WAVE
OVER THE WESTERN ATLC. OVER THE NEXT 24 HOURS CONVECTION WILL
SPREAD ACROSS THE LESSER ANTILLES AS A WESTWARD MOVING TROPICAL
WAVE CROSSES OVER THE ISLANDS AND INTO THE EASTERN CARIBBEAN.

...HISPANIOLA...

ISOLATED THUNDERSTORMS ARE OVER HISPANIOLA THIS
AFTERNOON...MAINLY DUE TO DAYTIME HEATING. THESE STORMS ARE
EXPECTED TO WEAKEN AROUND SUNSET...REDEVELOPING MONDAY
AFTERNOON. ADDITIONAL CONVECTION IS EXPECTED TO SPREAD ACROSS
THE ISLAND MONDAY NIGHT...ASSOCIATED WITH A WESTWARD MOVING
TROPICAL WAVE.

THE ATLANTIC OCEAN...

BROAD SURFACE RIDGING COVERS THE ATLC BEING ANCHORED BY A 1027
MB HIGH NEAR 29N37W. METEOSAT SATELLITE IMAGERY INDICATES
SAHARAN DRY AIR AND DUST COVERING MOST OF THE TROPICS S OF 20N.
THE ONLY NOTABLE CONVECTION OVER THE SUBTROPICAL ATLC S OF 31N
IS SCATTERED THUNDERSTORMS FROM 27N TO 29N BETWEEN 78W AND THE
FL EAST COAST. FOR INFORMATION ON TROPICAL WAVES SEE THE
TROPICAL WAVES SECTION ABOVE. SURFACE RIDGING WILL REMAIN
DOMINANT ACROSS THE ATLC THROUGH TUESDAY.

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

$$
LATTO
This weather bulletin was brought to you by:
www.nashvilleweather.net