000 AXNT20 KNHC 231800 TWDAT TROPICAL WEATHER DISCUSSION... NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUN 23 2012 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A BROAD AREA OF LOW PRESSURE COVERS THE GULF OF MEXICO TODAY CONCENTRATED NEAR A 1002 MB SURFACE LOW NEAR 26N88W. A SURFACE TROUGH EXTENDS THROUGH THE LOW CENTER FROM S OF THE FLORIDA PENINSULA AT 30N87W TO THE LOW AT 26N88W CONTINUING INTO THE BAY OF CAMPECHE ALONG 23N90W 21N93W. THE SYSTEM CONTINUES TO GAIN ORGANIZATION AND THERE IS A HIGH CHANCE OF DEVELOPMENT INTO A TROPICAL CYCLONE. A RECONNAISSANCE AIRPLANE IS CURRENTLY INVESTIGATING THE SYSTEM. IF THE PLANE FINDS A WELL-DEFINED CENTER THEN THE SYSTEM WILL BE CLASSIFIED AS A TROPICAL CYCLONE. GALE FORCE WINDS ARE EXPECTED TO ALREADY BE FORMING AROUND THE NE SEMICIRCLE OF THE LOW. CURRENTLY CONVECTION IS MAINLY JUST E OF THE SYSTEM WITH NUMEROUS MODERATE/SCATTERED STRONG CONVECTION RANGING FROM THE YUCATAN CHANNEL ACROSS WRN CUBA FROM 19N-22N BETWEEN 84W-87W...ACROSS THE FLORIDA STRAITS FROM 22N-24N BETWEEN 82W-86W...AND ACROSS THE ERN GULF FROM 24N-30N BETWEEN 81W-87W. THE MOVEMENT OF THE LOW IS SOMEWHAT UNCERTAIN AS MODEL GUIDANCE IS SPREAD ACROSS MUCH OF THE NRN GULF COAST. ALL AREAS OF THE NRN GULF COAST SHOULD MONITOR THE PROGRESS OF THE SYSTEM. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 17N39W TO 7N38W MOVING W AT 15-20 KT. THE WAVE ALIGNS WELL WITH A NARROW SURGE IN DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. VISIBLE SATELLITE IMAGERY ALSO INDICATES A CLEARING IN A LARGE AREA OF SAHARAN DUST THAT EXISTS BOTH E AND W OF THE WAVE AXIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE DUE TO THE DRY AIR EXCEPT FOR A SMALL AREA OF MODERATE CONVECTION NEAR THE S END OF THE AXIS FROM 6N-8N BETWEEN 38W-42W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF AFRICA NEAR 17N16W ALONG 11N22W TO 6N30W. THE ITCZ CONTINUES FROM 6N30W TO 6N38W. THE ITCZ DOES NOT CONTINUE PAST THIS POINT DUE TO THE PRESENCE OF ONLY NELY FLOW. HOWEVER...THERE IS STILL AN AREA OF WIND SPEED CONVERGENCE THAT IS PRODUCING SOME SHOWERS. ELSEWHERE ALONG THE ITCZ/MONSOON TROUGH...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-8N BETWEEN 18W-24W. SCATTERED MODERATE CONVECTION IS FROM 2N-5N BETWEEN 27W-38W. ...DISCUSSION... THE GULF OF MEXICO... BROAD LOW PRESSURE COVERS THE GULF OF MEXICO TODAY. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. MOST OF THE SHOWERS/THUNDERSTORMS ASSOCIATED THE TROUGH/LOW ARE E OF THE SYSTEM IMPACTING WRN CUBA AND PORTIONS OF FLORIDA. GALE FORCE WINDS ARE EXPECTED TO FORM BY 1800 UTC MAINLY E AND N OF THE LOW CENTER. THERE ARE ALSO ISOLATED SHOWERS W OF THE TROUGH AXIS AND IN THE BAY OF CAMPECHE ALONG WITH A FEW THUNDERSTORMS. ALOFT...AN UPPER LEVEL TROUGH EXTENDS ACROSS LOUISIANA INTO THE NW GULF SUPPORTING THE SURFACE TROUGH/LOW. UPPER LEVEL RIDGING COVERS THE SW GULF WITH AN ANTI-CYCLONIC CENTER OVER CENTRAL TEXAS. A SECOND UPPER LEVEL RIDGE EXTENDS FROM THE NW CARIBBEAN ACROSS THE FLORIDA PENINSULA. ANYONE INTERESTED IN THE GULF COAST SHOULD MONITOR THE PROGRESS OF THE SYSTEM AS THE FUTURE MOVEMENT IS SOMEWHAT UNCERTAIN. THE CARIBBEAN SEA... SHOWERS/THUNDERSTORMS COVER THE EXTREME NW CARIBBEAN TODAY ASSOCIATED WITH AN AREA OF BROAD LOW PRESSURE ACROSS THE GULF OF MEXICO. THE STRONGEST ACTIVITY IS CURRENTLY IN THE YUCATAN CHANNEL AND WRN CUBA. FLOODING AND MUDSLIDES ARE POSSIBLE OVER THE YUCATAN PENINSULA AND WRN CUBA IN AREAS THAT HAVE ALREADY RECEIVED LARGE AMOUNTS OF RAIN OVER THE PAST SEVERAL DAYS. THE REMAINDER OF THE BASIN IS UNDER MOSTLY FAIR CONDITIONS DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE WRN CARIBBEAN AND THE FLORIDA PENINSULA. WEAK UPPER TROUGHING COVERS THE ERN CARIBBEAN...BUT IS ALSO ACCOMPANIED BY DRY AIR ALOFT. TRADEWIND FLOW OF 15-20 KTS COVERS MUCH OF THE AREA. A FEW SHOWERS/THUNDERSTORMS ARE MOVING ACROSS THE SRN WINDWARD ISLANDS FROM THE TROPICAL ATLC. THE NRN LESSER ANTILLES ARE REPORTING DUST ALONG WITH PORTIONS OF THE NRN CARIBBEAN ISLANDS INCLUDING HISPANIOLA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OFF THE NE COAST OF FLORIDA ASSOCIATED WITH THE BROAD AREA OF LOW PRESSURE IN THE GULF OF MEXICO. WEAK SURFACE RIDGING COVERS THE REMAINDER OF THE W ATLC. HOWEVER...AN UPPER LEVEL LOW NEAR 29N66W IS SUPPORTING SOME SHOWERS/THUNDERSTORMS FROM 29N-31N BETWEEN 63W-67W AS WELL AS NEAR 26N67W. AN UPPER LEVEL TROUGH OVER THE CENTRAL ATLC SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N47W TO 31N59W. SCATTERED SHOWERS ARE ALONG THE AXIS. A PRE-FRONTAL SURFACE TROUGH IS ALONG 29N46W TO 25N54W. SCATTERED SHOWERS ARE WITHIN 50 NM EITHER SIDE OF THE AXIS. BOTH THE TROPICAL ATLC AND ERN ATLC ARE COVERED BY UPPER LEVEL RIDGING WHICH SUPPORTS BROAD SURFACE RIDGING AROUND A 1028 MB HIGH NEAR 36N22W PROVIDING FAIR CONDITIONS ACROSS THE REMAINDER OF THE BASIN. VISIBLE SATELLITE IMAGERY INDICATES A LARGE AREA OF SAHARAN DUST EXTENDS FROM THE COAST OF AFRICA ALL THE WAY TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON