[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171957 RRA
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED JUN 17 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
1600 UTC.

...SPECIAL FEATURES...

A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE
WESTERN ATLC AND A 1006 MB LOW OVER COLOMBIA SUPPORTS GALE FORCE
WINDS WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. THIS WIND
FIELD IS FORECAST TO DECREASE BELOW TO GALE FORCE THIS
AFTERNOON...THEN PULSE BACK TO GALE FORCE TONIGHT. SEE LATEST
NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02
KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 06N21W TO 15N21W MOVING W AT 15 KT.
THIS WAVE EMERGED OFF THE AFRICAN COAST ON TUESDAY MORNING AND
COINCIDES WITH A NORTHWARD EXTENSION OF DEEP TROPICAL MOISTURE
NOTED IN SSMI TPW IMAGERY. SCATTERED MODERATE CONVECTION IS FROM
06N TO 10N BETWEEN 16W AND 23W.

TROPICAL WAVE EXTENDS FROM 06N50W TO 15N50W MOVING W AT 20-25
KT. TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE EMBEDDED
WITHIN A RELATIVELY LOW AMPLITUDE AREA OF MOISTURE S OF 09N.
ISOLATED MODERATE CONVECTION IS FROM 07N TO 11N BETWEEN 48W AND
51W.

TROPICAL WAVE EXTENDS FROM 05N61W TO 15N61W MOVING W AT 15 TO 20
KT. THIS WAVE HAS BEEN TRACKED ON LONG TERM IR SATELLITE IMAGERY
AS WELL AS NOTED IN 700 MB HEIGHTS. THIS WAVE IS AT THE TRAILING
EDGE OF DEEP MOISTURE OVER THE CARIBBEAN. ISOLATED MODERATE
CONVECTION IS WITHIN 100 NM OF THE WAVE AXIS...INCLUDING THE
LEEWARD ISLANDS.

TROPICAL WAVE EXTENDS FROM 08N77N TO 17N75W MOVING W AT 20 KT.
THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE EMBEDDED
WITHIN A POLEWARD SURGE OF DEEP MOISTURE ACROSS THE CENTRAL AND
EASTERN CARIBBEAN SEA. CONVECTION ACROSS COLOMBIA IS MAINLY
ASSOCIATED WITH THE MONSOON TROUGH TO THE WEST OF THE WAVE.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO
12N19W. THE ITCZ AXIS EXTENDS FROM 10N23W THROUGH 07N34W TO
04N48W. ISOLATED MODERATE CONVECTION IS WITHIN 150 NM OF EITHER
SIDE OF THE ITCZ AXIS EAST OF 43W.

...DISCUSSION...

GULF OF MEXICO...
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE REMNANTS OF BILL
CONTINUE TO PRODUCE CLUSTERS OF MODERATE TO STRONG CONVECTION
FROM 26N TO THE TX COAST BETWEEN 94W AND 98W. DEEP TROPICAL
MOISTURE NOTED IN SSMI TPW ACROSS THE WESTERN HALF OF THE GULF
COMBINED WITH UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER TROUGH
OVER W TEXAS AND UPPER LEVEL HIGH PRESSURE OVER THE SW GULF
SUPPORTS ISOLATED THUNDERSTORMS S OF 26N AND W OF 94W. A MIDDLE
TO UPPER LEVEL SHORTWAVE TROUGH MOVING WESTWARD ACROSS FL
SUPPORTS ISOLATED MODERATE CONVECTION FROM 22N TO 29N BETWEEN
83W AND 88W. SURFACE RIDGING ANCHORED BY A PAIR OF HIGH CENTERS
OVER THE SOUTHEAST US AND NE OF THE BAHAMAS IS PRODUCING 10 TO
15 KT EAST TO SOUTHEAST SURFACE WINDS OVER MOST OF THE
GULF...EXCEPT AN AREA OF 20 KT IN THE VICINITY OF THE CONVECTION
ASSOCIATED WITH THE REMNANTS OF BILL OVER THE NW BASIN. OVER THE
NEXT 24 HOURS CONVECTION WILL DECREASE OVER THE NW GULF AS THE
REMNANTS OF BILL MOVE FARTHER INLAND. DEEP MOISTURE AND
FAVORABLE UPPER LEVEL CONDITIONS WILL SUPPORT CONVECTION OVER
THE SW GULF STARTING THURSDAY.

CARIBBEAN SEA...
TWO TROPICAL WAVES ARE OVER THE CARIBBEAN...ONE EXTENDING FROM
THE SW CARIBBEAN TO SE OF JAMAICA...THE OTHER CROSSING THE
LESSER ANTILLES. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE
DETAILS. AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN
NEAR 21N85W WITH WESTERLY FLOW ALOFT OVER THE CENTRAL AND
EASTERN CARIBBEAN. THE UPPER LOW IS OVER A FAIRLY DRY
ENVIRONMENT AND THEREFORE SUPPORTS ONLY ISOLATED THUNDERSTORMS
FROM 17N TO 20N BETWEEN 83W AND 88W. AN AREA OF UPPER LEVEL
DIFFLUENCE IS SUPPORTING SCATTERED TO NUMEROUS SHALLOW
THUNDERSTORMS FROM 09N TO 16N BETWEEN 79W AND 84W. FRESH TO
MODERATE TRADE WINDS COVER MOST OF THE CARIBBEAN BASIN.
HOWEVER...AN AREA OF STRONGER TRADE WINDS OF GALE FORCE IS
LOCATED N OF COLOMBIA DUE TO A TIGHT PRESSURE GRADIENT BETWEEN
WESTERN ATLC HIGH PRESSURE AND A 1006 MB LOW OVER N COLOMBIA.
PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. OVER
THE NEXT 24 HOURS THE GALE FORCE WINDS WILL PULSE BELOW AND
ABOVE GALE FORCE. CONVECTION WILL CONTINUE TO BE POSSIBLE OVER
THE WESTERN CARIBBEAN.

...HISPANIOLA...
AN INCREASE IN TROPICAL MOISTURE IS NOTED MOVING NORTHWARD
ACROSS THE ISLAND TODAY. THIS WILL BRING AN INCREASE IN
THUNDERSTORM COVERAGE THIS AFTERNOON. MOST OF THIS ACTIVITY WILL
DIMINISH DURING THE EVENING. SCATTERED THUNDERSTORMS WILL BE
POSSIBLE AGAIN ON THURSDAY.

ATLANTIC OCEAN...
A 1020 MB HIGH IS CENTERED NEAR 28N74W AND SUPPORTS WEAK
ANTICYCLONIC FLOW OVER THE SW NORTHERN ATLC. A MID LEVEL TROUGH
AXIS EXTENDS FROM NEAR 30N60W TO 26N68W...SUPPORTING WIDELY
SCATTERED MODERATE CONVECTION WITHIN 100NM OF EITHER SIDE OF THE
TROUGH AXIS. A PAIR OF COLD FRONTS ARE ALONG OUR AREA OF
DISCUSSION BOUNDARY NEAR 31N ALONG 58W AND 43W. SCATTERED
THUNDERSTORMS ARE POSSIBLE NEAR THE INTERSECTION OF THESE COLD
FRONTS WITH OUR BOUNDARY. 1031 MB HIGH PRESSURE CENTERED NW OF
THE AZORES SUPPORTS GENERALLY FAIR WEATHER ACROSS THE EASTERN
SUBTROPICAL ATLC. CONVECITON ALONG THE MID LEVEL TROUGH IS
FORECAST TO CONTINUE THROUGH THE NEXT 24 HOURS.

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

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