[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 210628
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU 21 APR 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
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 0000 UTC SURFACE ANALYSIS AND
SATELLITE IMAGERY THROUGH 0345 UTC.

...THE ITCZ...

ITCZ 9N8W 5N15W 4N27W...THE EQUATOR AT 35W...TO THE EQUATOR AT
40W AND 46W...AND 3N54W. STRONG SHOWERS AND THUNDERSTORMS FROM
THE EQUATOR TO 2S BETWEEN 38W AND 43W. ISOLATED STRONG SHOWERS
AND THUNDERSTORMS FROM 2S TO 2N BETWEEN 43W AND 48W. ISOLATED
MODERATE TO LOCALLY STRONG SHOWERS AND THUNDERSTORMS FROM 4S
TO THE EQUATOR BETWEEN 27W AND 38W...AND FROM 2N TO 4N BETWEEN
29W AND 32W. SCATTERED MODERATE TO ISOLATED STRONG SHOWERS AND
THUNDERSTORMS FROM 4N TO 8N BETWEEN 10W AND 16W...AND FROM 3N
TO 6N BETWEEN 17W AND 21W...AND FROM 7N TO 8N BETWEEN 54W AND
56W.

...DISCUSSION...

THE GULF OF MEXICO...
BROAD UPPER LEVEL ANTICYCLONIC FLOW SPANS INTERIOR MEXICO FROM
THE EASTERN PACIFIC OCEAN TO THE CENTRAL GULF OF MEXICO.
MIDDLE TO UPPER LEVEL NORTHWESTERLY WIND FLOW ON THE EASTERN
SIDE OF THE BROAD RIDGE ALONG 100W MOVES TOWARD THE BASE OF
A MIDDLE TO UPPER LEVEL TROUGH NOW OVER THE BAHAMAS. THIS TROUGH
RUNS FROM THE NORTHERN BAHAMAS TO EASTERN GEORGIA. MIDDLE TO
UPPER LEVEL DRY AIR COVERS THE GULF WATERS NORTHEAST OF 29N94W
23N79W ON THE SOUTH AND WEST SIDE OF THE TROUGH. THE PATTERN
WILL BECOME INCREASINGLY AMPLIFIED DURING THE NEXT 2 DAYS AS
A LONG-WAVE TROUGH SETS UP EAST OF FLORIDA. THE RIDGE WILL
CONTINUE TO BUILD NORTHWARD OVER MEXICO AND THE CENTRAL UNITED
STATES EFFECTIVELY BLOCKING UPSTREAM DISTURBANCES THROUGH THE
END OF THE WEEK. THE RIDGE-TROUGH COMBO WILL CREATE AN HIGHLY
CONFLUENT PATTERN ALOFT OVER THE AREA WHICH SHOULD LIMIT
SIGNIFICANT CLOUDS AND CONVECTION UNTIL THE NEXT COLD FRONT
WHICH CURRENTLY IS FORECAST TO MOVE OFF THE SOUTHEASTERN
TEXAS COAST ON SATURDAY.

THE CARIBBEAN SEA...
WEATHER CONDITIONS ACROSS PUERTO RICO AND SURROUNDING AREAS WILL
NOT CHANGE MUCH DURING THE NEXT SEVERAL DAYS AND IN FACT THEY
WILL DETERIORATE MORE. SHOWERS AND SCATTERED THUNDERSTORMS
THROUGHOUT THE EARLY MORNING HOURS OF TODAY AND INTO THURSDAY
MORNING ESPECIALLY ALONG THE COASTAL AREAS OF THE SOUTH AND
EAST. THE POTENTIAL FOR FLOODING REMAINS HIGH BECAUSE ADDITIONAL
RAIN CELLS CONTINUE TO DEVELOP OVER INTERIOR PUERTO RICO.
THURSDAY PROMISES TO BE ANOTHER ACTIVE DAY WITH THE DISSIPATING
STATIONARY FRONT TO REMAIN TO THE NORTHWEST OF PUERTO RICO. THE
FRONT IS NOT EXPECTED TO RETROGRESS THROUGH FRIDAY. MIDDLE TO
UPPER LEVEL NORTHWESTERLY WIND FLOW POURS INTO THE AREA FROM THE
GULF OF MEXICO...THROUGH THE YUCATAN CHANNEL AND ACROSS THE
GREATER ANTILLES TO A BASE NEAR 13N69W IN THE SOUTH CENTRAL
CARIBBEAN SEA. PURELY UPPER LEVEL SOUTHWESTERLY WIND FLOW MOVES
ACROSS THE AREA...FROM NICARAGUA AND THE SOUTHWESTERN CORNER OF
THE AREA NORTHEASTWARD BEYOND THE NORTHEASTERN CORNER. THIS
SOUTHWESTERLY WIND FLOW COMES FROM AN UPPER LEVEL RIDGE OVER
SOUTH AMERICA...AND COMBINES WITH THE MIDDLE TO UPPER LEVEL
CYCLONIC WIND FLOW OF THE ATLANTIC TO CARIBBEAN SEA TROUGH.
MIDDLE TO UPPER LEVEL TROUGH THROUGH 32N56W TO 27N62W TO 19N66W
JUST NORTH OF PUERTO RICO TO 13N69W IN THE SOUTH CENTRAL
CARIBBEAN SEA. THIS TROUGH SUPPORTS THE EAST CENTRAL ATLANTIC
COLD FRONT THROUGH 32N35W TO 30N40W TO 28N48W...STATIONARY FRONT
CONTINUES FROM 28N48W TO 25N55W AND 22N61W. SURFACE TROUGH FROM
19N80W TO 16N83W TO SOUTHERN NICARAGUA NEAR 12N85W. BROKEN LOW
TO MIDDLE LEVEL CLOUDS AND POSSIBLE PRECIPITATION FROM 15N TO
20N BETWEEN 73W AND 84W.

THE ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL TROUGH THROUGH 32N56W TO 27N62W TO 19N66W
JUST NORTH OF PUERTO RICO TO 13N69W IN THE SOUTH CENTRAL
CARIBBEAN SEA. THIS TROUGH SUPPORTS THE EAST CENTRAL ATLANTIC
COLD FRONT THROUGH 32N35W TO 30N40W TO 28N48W...STATIONARY FRONT
CONTINUES FROM 28N48W TO 25N55W AND 22N61W. DISSIPATING
STATIONARY FRONT THROUGH 20N65W TO EASTERN DOMINICAN REPUBLIC
AND THE MONA PASSAGE TO 17N70W. ONE SURFACE RIDGE GOES FROM THE
EASTERN ATLANTIC OCEAN THROUGH A 1023 MB HIGH PRESSURE CENTER
NEAR 34N59W TO 29N75W INTO THE NORTH CENTRAL GULF OF MEXICO NEAR
29N91W. A SECOND SURFACE RIDGE...EAST OF THE ATLANTIC FRONTAL
BOUNDARY...RUNS FROM A 1025 MB EASTERN ATLANTIC HIGH PRESSURE
CENTER...TO 27N33W 16N52W TO 11N60W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION WITHIN 120 NM
ON EITHER SIDE OF 32N46W 27N54W 23N59W 20N64W. MIDDLE TO UPPER
LEVEL TROUGH GOES FROM A CYCLONIC CIRCULATION CENTER NEAR 19N27W
TO 5N30W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE
PRECIPITATION ARE CURVING NORTHWARD...NORTH OF 10N EAST OF 30W...
ON THE EASTERN SIDE OF THIS TROUGH.

$$
MT


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