000
AXNT20 KNHC 200005
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 PM EDT MON APR 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC...

...THE ITCZ...

FROM 5N10W TO 2N20W 1N30W 1N40W TO THE EQUATOR ALONG 50W.
WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG 
THUNDERSTORMS ARE WITHIN 150 NM ON EITHER SIDE OF 4N10W 
1N30W...THE EQUATOR ALONG 40W TO 3S50W.

...DISCUSSION...

THE GULF OF MEXICO...
ONE MIDDLE LEVEL TO UPPER LEVEL TROUGH IS MOVING THROUGH THE
AREA FROM WEST TEXAS INTO NORTH CENTRAL MEXICO. SHOWERS AND
POSSIBLE THUNDERSTORMS COVER THE AREA TO THE NORTH OF 26N 
BETWEEN 102W AND 106W. A SECOND MIDDLE LEVEL TO UPPER LEVEL 
TROUGH IS MOVING THROUGH THE EASTERN GULF OF MEXICO. IT IS
ALONG A LINE FROM WESTERN CUBA NEAR 22N85W TO 25N84W...
TO 28N84W OFF THE WESTERN FLORIDA COAST...BEYOND SOUTHEASTERN 
GEORGIA. A SURFACE TROUGH EXTENDS NORTHWARD...FROM A 1013 MB
LOW PRESSURE CENTER THAT IS IN THE WESTERNMOST PART OF THE 
FLORIDA PANHANDLE...INTO NORTH CENTRAL ALABAMA. ISOLATED 
MODERATE SHOWERS RIGHT NOW ARE IN CENTRAL FLORIDA FROM 28N TO 
29N...AND MOVING THROUGH THE FLORIDA PANHANDLE BETWEEN 83W AND 
86W. THE SOUTHERN END OF AN ATLANTIC OCEAN COLD FRONT PASSES 
OVER ELEUTHERA ISLAND AND ANDROS ISLAND IN THE BAHAMAS TO
24N80W IN THE STRAITS OF FLORIDA. THE SURFACE PRESSURE GRADIENT 
IS WEAK ACROSS THE AREA.

THE CARIBBEAN SEA...
A SURFACE TROUGH EXTENDS FROM THE ATLANTIC OCEAN WATERS THAT ARE 
BETWEEN THE BAHAMAS AND CUBA NEAR 22N76W...ACROSS CUBA...INTO 
THE CARIBBEAN SEA NEAR 17N82W. WEAK MIDDLE LEVEL TO UPPER LEVEL
CYCLONIC FLOW COVERS THE AREA TO THE NORTHWEST OF THE 22N76W TO
17N82W SURFACE TROUGH. THIS CYCLONIC FLOW IS RELATED TO THE 
EASTERN GULF OF MEXICO TROUGH THAT EXTENDS FROM 22N85W BEYOND 
SOUTHEASTERN GEORGIA. BROAD UPPER LEVEL SOUTHWESTERLY WIND FLOW
COVERS THE REST OF THE CARIBBEAN SEA TO THE EAST OF THE AREA OF 
THE CYCLONIC FLOW. THE SOUTHWESTERLY WIND FLOW IS RELATED TO 
LARGE-SCALE UPPER LEVEL ANTICYCLONIC WIND FLOW THAT COVERS THE 
ATLANTIC OCEAN TO THE WEST OF 30W. THE SURFACE PRESSURE GRADIENT 
IS WEAK ACROSS THE AREA.

THE ATLANTIC OCEAN...
UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA TO THE EAST OF
THE LINE FROM THE CENTRAL BAHAMAS BEYOND BERMUDA. MIDDLE LEVEL
TO UPPER LEVEL SOUTHWESTERLY FLOW COVERS THE AREA TO THE 
NORTHWEST OF THE LARGE-SCALE ANTICYCLONIC FLOW. THIS 
SOUTHWESTERLY FLOW IS A COMBINATION OF THE MERGING WIND 
REGIMES...ONE AROUND THE EASTERN GULF OF MEXICO TROUGH...AND THE 
OTHER ONE AROUND THE ATLANTIC OCEAN ANTICYCLONE. A COLD FRONT 
PASSES THROUGH 33N60W TO 30N65W...TO A 1009 MB LOW PRESSURE 
CENTER THAT IS NEAR 28N67W...TO THE BAHAMAS NEAR ELEUTHERA 
ISLAND AND THEN ANDROS ISLAND...AND EVENTUALLY TO 24N80W IN THE 
STRAITS OF FLORIDA. SHOWERS ARE POSSIBLE WITHIN 120 NM ON EITHER 
SIDE OF THE FRONT. A TROUGH ON WATER VAPOR IMAGERY IS ALONG 
24W/25W FROM 10N BEYOND 32N. THIS TROUGH SUPPORTS AN EASTERN 
ATLANTIC OCEAN COLD FRONT THAT PASSES THROUGH 32N19W TO 30N19W 
28N20W 20N30W TO 16N40W. SHOWERS ARE TO THE NORTH OF 31N BETWEEN 
20W AND 30W. SURFACE ANTICYCLONIC FLOW COVERS THE ATLANTIC OCEAN 
FROM 18N TO 32N BETWEEN 40W AND 60W...AROUND A 1020 MB HIGH 
PRESSURE CENTER THAT IS NEAR 26N49W.

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

$$
MT