000 AXNT20 KNHC 170600 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU MAY 17 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ... 10N12W 7N20W 6N27W 4N40W 3N50W...TO 4N53W IN FRENCH GUIANA. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS WITHIN 90 TO 120 NM ON EITHER SIDE OF 6N11W 6N20W 5N30W 4N37W 2N42W 3N50W...AND SOUTH OF 8N BETWEEN 52W AND 58W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH THAT ORIGINATES IN THE MISSISSIPPI VALLEY AREA OF THE U.S.A. REACHES THE GULF OF MEXICO NEAR 27N92W. THIS TROUGH SUPPORTS A COLD FRONT FROM SOUTHEASTERN MISSISSIPPI TO THE SOUTH CENTRAL LOUISIANA COAST. A STATIONARY FRONT CUTS ACROSS THE NORTHWESTERN GULF WATERS FROM THE LOUISIANA COAST TO THE LOWER TEXAS COAST TO 27N100W IN MEXICO. THE STATIONARY FRONT CONTINUES NORTHWESTWARD ACROSS MEXICO BEYOND 30N108W. ISOLATED MODERATE SHOWERS ARE NORTH OF 28N BETWEEN 84W AND THE TEXAS COAST. OTHER ISOLATED MODERATE SHOWERS ARE SOUTH OF 27N BETWEEN 85W AND 93W MOVING SOUTH-SOUTHWEST. A WEAK SURFACE PRESSURE GRADIENT COVERS THE REST OF THE GULF OF MEXICO AWAY FROM THE FRONT. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA SOUTH OF 23N WEST OF 86W. THIS ANTICYCLONIC FLOW MOVES FROM THE EASTERN PACIFIC OCEAN NORTH OF THE ITCZ EAST OF 120W...ACROSS MEXICO...INTO THE SOUTHWESTERN GULF OF MEXICO. THE CARIBBEAN SEA... A DEVELOPING MIDDLE TO UPPER LEVEL TROUGH STARTS IN THE ATLANTIC OCEAN NEAR 32N75W...PASSES OVER THE NORTHERN BAHAMAS TO THE STRAITS OF FLORIDA. A SURFACE TROUGH RUNS FROM ANDROS ISLAND TO CUBA NEAR 22N79W INTO THE NORTHWESTERN PART OF THE AREA NEAR 20N81W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS COVER THE AREA FROM THE CARIBBEAN SEA NEAR 16N TO THE BAHAMAS NEAR 23N BETWEEN 70W AND 82W. A SECOND SURFACE TROUGH RUNS FROM THE COLOMBIA COAST NEAR 9N76W TO 12N79W TO 17N81W. ISOLATED MODERATE SHOWERS ARE FROM 10N TO 15N BETWEEN 79W AND JUST OFF THE NORTHEASTERN NICARAGUA COAST ALONG 83W/84W. STRONG SHOWERS AND THUNDERSTORMS ARE ALONG THE PANAMA COAST BETWEEN 78W AND 80W WITH THE ITCZ. STRONG SHOWERS AND THUNDERSTORMS ARE OVER INTERIOR COSTA RICA BETWEEN THE BORDER WITH PANAMA AND 85W. BROAD AND DRY UPPER LEVEL NORTHWESTERLY WIND FLOW MOVES ACROSS THE AREA. HIGH CLOUDS ARE SOUTH OF 16N BETWEEN 70W AND NICARAGUA. THE ATLANTIC OCEAN... A DEVELOPING MIDDLE TO UPPER LEVEL TROUGH IS ALONG 32N75W... TO THE NORTHERN BAHAMAS NEAR 27N78W TO THE STRAITS OF FLORIDA. A SURFACE TROUGH IS ALONG 27N77W TO ANDROS ISLAND TO CUBA NEAR 22N79W INTO THE NORTHWESTERN CARIBBEAN SEA NEAR 20N81W. SCATTERED STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN A 30 NM RADIUS OF 23N73W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WITHIN 60 NM ON EITHER SIDE OF 30N74W 27N69W 24N66W 21N64W. OTHER ISOLATED MODERATE SHOWERS ARE NORTH OF 20N WEST OF 60W. A MIDDLE TO UPPER LEVEL TROUGH RUNS FROM A CYCLONIC CIRCULATION CENTER NEAR 28N50W TO 20N54W AND 15N55W. THIS TROUGH SUPPORTS THE ATLANTIC OCEAN STATIONARY FRONT THAT PASSES THROUGH 32N42W TO 24N50W TO 20N60W AND 20N65W. ISOLATED MODERATE SHOWERS ARE FROM 19N BEYOND 32N BETWEEN 43W AND 52W. A SURFACE RIDGE RUNS FROM A 1029 MB HIGH PRESSURE CENTER NEAR 35N55W TO BERMUDA TO 30N75W. A FAR EASTERN ATLANTIC OCEAN MIDDLE TO UPPER LEVEL TROUGH RUNS FROM ONE CYCLONIC CIRCULATION CENTER NEAR 32N23W TO 25N27W TO 15N36W. A SURFACE RIDGE PASSES THROUGH 32N33W TO 23N38W TO 14N42W. UPPER LEVEL SOUTHWESTERLY WIND FLOW TRAVELS FROM 8N40W TO THE EAST OF THE 32N22W 10N44W TROUGH... EVENTUALLY ACROSS THE CAPE VERDE ISLANDS AND AFRICA. $$ MT