[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202350
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT APR 20 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 6N11W TO 3N16W WHERE THE ITCZ BEGINS AND CONTINUES
ALONG 2N22W 3N32W 3N46W TO INLAND OVER SOUTH AMERICA NEAR 2N51W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
FROM 3N TO THE EQUATOR BETWEEN 5W-24W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER TROUGH COVERS MOST OF THE GULF AND THE E CONUS TO
THE EASTERN SEABOARD SUPPORTING A COLD FRONT THAT AT 20/2100 UTC
ENTERS THE GULF OVER THE FLORIDA PENINSULA BETWEEN BOCA RATON
AND NAPLES TO 24N86W WHERE IT PULLS UP STATIONARY AS IT
CONTINUES TO INLAND OVER THE YUCATAN PENINSULA NEAR MERIDA.
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN
240 NM N AND W OF THE FRONT. A SURFACE RIDGE IS BUILDING IN
BEHIND THE FRONT ANCHORED BY A 1028 MB HIGH OVER THE GREAT
LAKES. COLD FRONT WILL STALL AND WEAKEN TONIGHT THEN SLOWLY
DISSIPATE THROUGH MON. ANOTHER COLD FRONT IS EXPECTED TO MOVE
INTO THE NW GULF EARLY WED.

CARIBBEAN SEA...
AN UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS CENTRAL
AMERICA INTO THE CARIBBEAN OVER THE GULF OF HONDURAS E TO
CENTRAL CUBA. AN UPPER LOW IS N OF PUERTO RICO EXTENDING AN
UPPER TROUGH INTO THE CARIBBEAN NEAR THE MONA PASSAGE THEN
EXTENDS SW TO COSTA RICA/NICARAGUA. THE TRADE WINDS ARE
ENHANCING SCATTERED SHOWERS GENERATED BY THE UPPER TROUGH OVER
THE NE CARIBBEAN N OF 15N E OF 70W INCLUDING PUERTO RICO...THE
VIRGIN AND LEEWARD ISLANDS. GUADELOUPE REPORTED EARLIER THIS
MORNING OVER 3 INCHES OF RAIN IN THE PAST 24 HOURS. A SECOND
UPPER RIDGE ANCHORED IN THE TROPICAL ATLC CLIPS THE SE
CARIBBEAN. AFTERNOON THUNDERSTORMS ARE DEVELOPING INLAND OVER
CUBA...W JAMAICA...AND HISPANIOLA. THE MONSOON TROUGH EXTENDS
BETWEEN COLOMBIA AND COSTA RICA ALONG 9W/10W GENERATING
SCATTERED SHOWERS S OF 11N W OF 80W. THIS IS LEAVING THE
REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS EVENING.
SURFACE RIDGE OVER THE W AND CENTRAL ATLC WILL MAINTAIN MODERATE
TO FRESH TRADE WINDS ACROSS THE CARIBBEAN TONIGHT. WINDS AND
SEAS WILL GRADUALLY DIMINISH SUN THROUGH WED.

ATLANTIC OCEAN...
THE UPPER TROUGH OVER THE E CONUS AND GULF OF MEXICO IS DRAPING
A COLD FRONT INTO THE W ATLC AT 20/2100 UTC NEAR 32N74W ALONG
28N78W THEN ACROSS FLORIDA INTO THE GULF OF MEXICO NEAR BOCA
RATON. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE
WITHIN 210 NM W OF THE FRONT. THE UPPER RIDGE OVER THE CARIBBEAN
EXTENDS INTO THE W ATLC ACROSS CENTRAL CUBA AND THE CENTRAL
BAHAMAS TO BEYOND 32N70W. THIS UPPER RIDGE IS PROVIDING
DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 120 NM E OF THE FRONT. AN UPPER LOW IS N OF
PUERTO RICO NEAR 21N66W EXTENDING AN UPPER TROUGH INTO THE
CARIBBEAN NEAR THE MONA PASSAGE AND GENERATING SCATTERED SHOWERS
FROM 15N-20N BETWEEN 60W-69W INCLUDING PUERTO RICO...THE VIRGIN
AND LEEWARD ISLANDS. THE REMAINDER OF THE CENTRAL ATLC IS
DOMINATED BY A BROAD UPPER RIDGE. A SURFACE RIDGE DOMINATES THE
W AND CENTRAL ATLC W OF 45W TO THE COLD FRONT ANCHORED WELL N OF
THE DISCUSSION AREA. AN UPPER TROUGH IS IN THE E/CENTRAL ATLC IS
N OF 20N BETWEEN 30W-48W SUPPORTING A COLD FRONT THAT ENTERS THE
REGION NEAR 32N36W ALONG 28N40W TO 26N45W AND A SURFACE TROUGH
THAT EXTENDS FROM 30N36W TO 24N44W. SCATTERED SHOWERS DOT THE
AREA N OF 25N BETWEEN 33W-43W. A WEAK 1011 MB SURFACE LOW IS
JUST W OF THE CANARY ISLANDS NEAR 29N19W WITH A SURFACE TROUGH
EXTENDING E-SE TO 27N14W. W ATLC COLD FRONT WILL BECOME
STATIONARY TONIGHT AND SLOWLY WEAKEN INTO A TROUGH. THE TROUGH
WILL THEN DRIFT NORTHWARD SUN AND MON. HIGH PRESSURE WILL BUILD
S ALONG THE SE U.S. COAST AND NE FLORIDA COAST MON AND TUE AS
THE TROUGH MOVES NE AWAY FROM THE AREA.

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

$$
PAW


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