000 AXNT20 KNHC 141103 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT MAR 14 2009 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N5W 1N17W CROSSING THE EQUATOR NEAR 24W EXTENDING TO 2S32W INTO NE BRAZIL NEAR 5S39W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-5N BETWEEN 6W-14W. SCATTERED MODERATE CONVECTION IS S OF 3N BETWEEN 28W-30W. ...DISCUSSION... GULF OF MEXICO... DIFFLUENT WESTERLY FLOW ALOFT IS PRESENT ACROSS THE WESTERN GULF REGION. DEEP LAYER ATMOSPHERIC LIFT IN THIS FLOW IS SUPPORTING A SURFACE COLD FRONT IN THE W GULF THAT EXTENDS FROM S LOUISIANA NEAR 30N92W TO 26N94W TO 22N96W AND A SURFACE STATIONARY FRONT THAT EXTENDS FROM 22N96W TO THE COAST OF MEXICO NEAR 20N97W. LOW LEVEL CONVERGENCE AND DEEP LAYER ATMOSPHERIC LIFT ARE SUPPORTING SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THE FRONTS. TO THE NW OF THE FRONTS...NW TO N SURFACE WINDS OF 15 TO 20 KT ARE OCCURRING...WHERE A RELATIVELY COOLER AND DRIER AIRMASS IS PRESENT. THIS COOLER AIR IS OVER RELATIVELY WARMER WATERS... RESULTING IN LAYERS OF SCATTERED TO OVERCAST STRATOCUMULUS CLOUDS TO THE NW OF THE FRONTS. TO THE SE OF THE FRONTS...DEEP LAYER DRY AIR IS RESULTING IN GENERALLY FAIR WEATHER CONDITIONS ACROSS MUCH OF THE CENTRAL AND SE GULF. CARIBBEAN SEA... STRONG SURFACE HIGH PRESSURE BUILDING SOUTHWARD OVER THE W ATLC WILL MAINTAIN MODERATE TO STRONG TRADES OVER MUCH OF THE CARIBBEAN SEA THROUGH MONDAY. GENERALLY FAIR WEATHER CONDITIONS ARE OCCURRING ACROSS MUCH OF THE CARIBBEAN REGION...WHERE DEEP LAYER DRY AIR IS PRESENT. HOWEVER...THE TRADE WINDS ARE ADVECTING PATCHES OF LOW LEVEL MOISTURE WESTWARD ACROSS THE CARIBBEAN...WITH SCATTERED SHOWERS EMBEDDED WITHIN THESE PATCHES OF LOW LEVEL MOISTURE. THE GREATEST CONCENTRATION OF THESE SHOWERS IS FROM 15N-19N BETWEEN 75W-81W. ALSO...INCREASED UPPER LEVEL MOISTURE IS STREAMING NORTHEASTWARD ACROSS PORTIONS OF THE SW CARIBBEAN. ATLANTIC OCEAN... SOUTHWESTERLY FLOW ALOFT IS PRESENT ACROSS THE FAR W ATLC. DEEP LAYER ATMOSPHERIC LIFT IN THIS FLOW IS SUPPORTING A SURFACE STATIONARY FRONT EXTENDING FROM THE E FLORIDA PENINSULA NEAR 30N81W TO 31N78W TO 32N76W TO NE OF THE DISCUSSION AREA. LOW LEVEL CONVERGENCE AND DEEP LAYER ATMOSPHERIC LIFT ARE SUPPORTING SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THIS FRONT. TO THE SE OF THIS FRONT...AN UPPER LEVEL RIDGE IS IN PLACE. DEEP LAYER DRY AIR AND ATMOSPHERIC STABILITY IN THE VICINITY OF THIS UPPER LEVEL RIDGE ARE RESULTING IN GENERALLY FAIR WEATHER CONDITIONS TO THE SE OF THE FRONT. FARTHER TO THE E...AN UPPER LEVEL TROUGH IS N OF 25N BETWEEN 28W-39W...WITH AN UPPER LEVEL LOW NEAR 31N36W. THE UPPER LEVEL LOW AND UPPER LEVEL TROUGH ARE ASSOCIATED WITH A 1003 MB SURFACE LOW NEAR 29N37W...A DISSIPATING SURFACE STATIONARY FRONT EXTENDING FROM 14N41W TO 23N33W TO 31N32W...AND A SURFACE OCCLUDED FRONT EXTENDING FROM 31N32W TO 32N35W TO 31N39W. ATMOSPHERIC INSTABILITY...UPPER LEVEL DIFFLUENCE...AND LOW LEVEL CONVERGENCE IN THE VICINITY OF THE SURFACE LOW AND SURFACE FRONTS ARE SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS N OF 26N BETWEEN 28W-37W. THIS ACTIVITY IS BEING SUPPORTED BY UPPER LEVEL DIVERGENCE IN THE NE QUADRANT OF A 100-110 KT UPPER LEVEL JET MAXIMUM LOCATED SE OF THE UPPER LOW. THE SURFACE LOW IS FORECAST TO MOVE NORTHEASTWARD DURING THE NEXT DAY AND BE LOCATED NEAR 32N32W AS A 1007 MB SURFACE LOW AT 15/0600 UTC. FARTHER TO THE E...SUBSIDENCE ASSOCIATED WITH A SURFACE RIDGE IS RESULTING IN FAIR WEATHER CONDITIONS ACROSS THE E ATLC. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL RIDGE IS S OF 13N E OF 51W WITH AN UPPER LEVEL HIGH NEAR 10N21W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER LEVEL HIGH AND UPPER LEVEL RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ. $$ COHEN