[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 240004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU APR 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL
ATLANTIC NEAR 07N12W TO 04N17W WHERE THE ITCZ BEGINS AND
CONTINUES TO 01S28W JUST E OF A SURFACE TROUGH ALONG 30W. THE
ITCZ RESUMES W OF THE SURFACE TROUGH NEAR 02S32W AND CONTINUES
TO THE NORTHERN COAST OF BRAZIL NEAR 02S44W. SCATTERED TO
ISOLATED MODERATE CONVECTION IS FROM 07S TO 02N W OF 24W.
SIMILAR CONVECTION IS FROM THE EQUATOR TO 05N W OF 45W.

...DISCUSSION...

GULF OF MEXICO...

A SHORTWAVE UPPER TROUGH SUPPORTS A 1009 MB LOW NEAR 37N47W FROM
WHICH A COLD FRONT EXTENDS ACROSS THE CENTRAL ATLC TRANSITIONING
TO A STATIONARY FRONT THAT STARTS TO DISSIPATE N OF THE SOUTHERN
BAHAMAS. THE DISSIPATING STATIONARY FRONT THEN EXTENDS NW ACROSS
THE NORTHERN BAHAMAS TO SOUTH OF LAKE OKEECHOBEE THE ACROSS THE
NE GULF OF MEXICO ALONG 26N82W TO 29N86W TO SE LOUISIANA NEAR
29N91W. A MIDDLE TO UPPER LEVEL TROUGH WITH BASE OVER THE SW N
ATLC ALONG WITH A RIDGE ANCHORED OVER THE SOUTHERN GULF IS
GENERATING A SLIGHT DIFFLUENT ENVIRONMENT OVER THE NE GULF. WIND
FLOW AROUND THE RIDGE ALSO ADVECTS MOISTURE FROM THE EPAC WATERS
TO THE NORTHERN GULF WHERE SSMI TPW IMAGERY CONTINUE TO SHOW
ABUNDANT MOISTURE. DEEP LAYER MOISTURE ENHANCES SCATTERED
SHOWERS AND TSTMS WITHIN 100 NM S OF THE FRONT AND ISOLATED
SHOWERS AND TSTMS N OF THE BOUNDARY...INCLUDING THE FLORIDA
PENINSULA. FOG IS POSSIBLE FOR THE NW GULF N OF 27N AND ALONG
COASTAL WATERS OF THE YUCATAN PENINSULA AS INDICATED BY GOES-13
MEDIUM TO HIGH IFR FOG PROBABILITIES. FAIR WEATHER IS ELSEWHERE.
LIGHT VARIABLE WINDS UP TO 10 KT ARE ACROSS THE BASIN. THE
DISSIPATING FRONT IS FORECAST TO WEAKEN INTO A SURFACE TROUGH
LATE TONIGHT THAT IS EXPECTED TO DISSIPATE FRIDAY MORNING. LOW
PRESSURE WILL DOMINATE ACROSS THE BASIN FOR THE NEXT THREE DAYS.

CARIBBEAN SEA...

NORTHERLY FLOW ASSOCIATED WITH A WEAK CENTER OF HIGH PRESSURE
OVER THE SW N ATLC WATERS AND E-SE TRADES OVER THE NORTHERN
CARIBBEAN WATERS IS GENERATING AN ELONGATED AREA OF LOW PRESSURE
OVER CUBA...WHICH ALONG MIDDLE TO LOW LEVEL MOISTURE BEING
ADVECTED FROM THE NORTHERN GULF OF MEXICO SUPPORT SCATTERED
SHOWERS AND TSTMS OVER CENTRAL CUBA...EXTENDING TO ADJACENT
WATERS. MIDDLE TO LOW LEVEL MOISTURE ASSOCIATED WITH THE FRONTAL
BOUNDARY ACROSS THE SW N ATLC IS BEING ADVECTED TO
HISPANIOLA...WHICH ALONG A DIFFLUENT ENVIRONMENT ALOFT SUPPORT
CLOUDINESS ACROSS THE ISLAND. HOWEVER...SHOWERS ARE NOT EXPECTED
AS DEEP LAYER DRY AIR DOMINATES ACROSS THE ISLAND. ISOLATED
SHOWERS ARE POSSIBLE ACROSS THE WINDWARD PASSAGE. FAIR WEATHER
PREVAILS ELSEWHERE. TRADES OF 15 KT DOMINATES ACROSS THE
CARIBBEAN...INCREASING TO 20 TO 25 KT ALONG THE COAST OF
COLOMBIA. NO SIGNIFICANT CHANGES ARE EXPECTED DURING THE NEXT
TWO DAYS.

HISPANIOLA...

A MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT IS OVER THE
ISLAND...HOWEVER CURRENTLY DEEP LAYER DRY AIR IS PREVENTING THE
DEVELOPMENT OF CONVECTION. DRY AIR IS FORECAST TO PREVAIL ACROSS
THE ISLAND THROUGH THU NIGHT. MOISTURE AHEAD OF A FRONT TO MOVE
N OF THE ISLAND WILL ENHANCE SHOWERS OVER HISPANIOLA FRIDAY
MORNING.

ATLANTIC OCEAN...

A SHORTWAVE UPPER TROUGH SUPPORTS A 1009 MB LOW NEAR 37N47W FROM
WHICH A COLD FRONT EXTENDS ACROSS THE CENTRAL ATLC ALONG 30N47W
SW TO 27N57W WHERE IT TRANSITIONS TO A STATIONARY FRONT SW TO
25N68W THEN STARTS TO WEAKEN TO THE NORTHERN BAHAMAS NEAR 26N78W
INTO SOUTHERN FLORIDA NW ACROSS THE NE GULF TO SOUTHERN
LOUISIANA. SCATTERED MODERATE CONVECTION IS N OF 25N BETWEEN 45W
AND 64W. SIMILAR CONVECTION ALONG WITH TSTMS ARE S OF THE
BOUNDARY TO ANDROS ISLAND W OF 76W. SURFACE RIDGING AND FAIR
WEATHER PREVAILS ELSEWHERE. A NEW COLD FRONT ENTERS THE SW N
ATLC FRIDAY MORNING ENHANCING SCATTERED TO ISOLATED SHOWERS.

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

$$
NR


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