000 AXNT20 KNHC 141046 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE AUG 14 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION FOUR IS CENTERED NEAR 12.0N 36.8W AT 14/0900 UTC MOVING W AT 17 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. THE ASSOCIATED DEEP CONVECTION REMAINS DISPLACED TO THE W OF THE CENTER DUE TO EASTERLY SHEAR OVER THE SYSTEM. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 9N-13N BETWEEN 37W-42W. THE SYSTEM WILL CONTINUE TO MOVE RATHER BRISKLY IN A GENERALLY WESTWARD MOTION DURING THE NEXT COUPLE OF DAYS ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYER RIDGE. SOME STRENGTHENING IS FORECAST...AND THE DEPRESSION COULD BECOME A TROPICAL STORM LATER TODAY. A 1007 MB LOW IS CENTERED NEAR 22N88W...OR JUST OFF THE N COAST OF THE YUCATAN PENINSULA. THE ASSOCIATED TROPICAL WAVE IS JUST OT THE W OF THE LOW CENTER. THE SYSTEM CONTINUES INTERACT WITH AN UPPER LOW MOVING ACROSS THE W GULF OF MEXICO AND IS PRODUCING WIDESPREAD CLOUDINESS WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE SE GULF...S OF 27N BETWEEN 83W-90W. UPPER-LEVEL WINDS CONTINUE TO BECOME MORE FAVORABLE FOR DEVELOPMENT OF THIS SYSTEM...AND A TROPICAL DEPRESSION COULD FORM LATER TODAY AS THE LOW MOVES TO THE WNW NEAR 10-15 KT. INTERESTS IN THE W GULF OF MEXICO SHOULD CONTINUE TO MONITOR THE PROGRESS OF THIS SYSTEM. AN AIR FORCE RESERVE RECONNAISSANCE PLANE IS SCHEDULED TO INVESTIGATE THIS SYSTEM TOMORROW AFTERNOON...IF NECESSARY. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 23W/24W S OF 19N MOVING W 15-20 KT WITH A 1010 MB LOW JUST S OF THE CAPE VERDE ISLANDS NEAR 14N24W. THIS WAVE HAS A WELL DEFINED LOW/MID LEVEL ROTATION WITH SCATTERED MODERATE CONVECTION WITHIN 60 NM OF LINE FROM 11N23W TO 13N28W. TROPICAL WAVE IS ALONG 48W S OF 16N MOVING W 15 KT. WEAK LOW/MID LEVEL ROTATION IS EMBEDDED WITHIN THE ITCZ WITH LOW AMPLITUDE LOW LEVEL INVERTED-V CURVATURE OBSERVED. NO ASSOCIATED SHOWER ACTIVITY/CONVECTION. A TROPICAL WAVE ASSOCIATED WITH THE 1007 MB LOW IN THE SPACIAL FEATURES CONTINUES TO MOVE JUST W OF THE LOW. THE WAVE IS ALONG 89W S OF 26N MOVING W NEAR 10 KT. INVERTED-V CURVATURE IS CLEARLY DISCERNIBLE IN THE E PACIFIC REGION. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 15N15W 14N27W 13N34W 10N46W 11N62W. SEE SPACIAL FEATURES ABOVE. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 3N-10N E OF 37W. DISCUSSION... GULF OF MEXICO... THE MAIN FOCUS THIS MORNING CONTINUES TO BE THE 1007 MB LOW JUST OFF THE N COAST OF THE YUCATAN AS DESCRIBED IN THE SPECIAL FEATURES ABOVE. A MID/UPPER LOW IS IN THE NW GULF NEAR 26N96W AND IS SUPPORTING A BAND OF SCATTRED THUNDERSTORMS ALONG THE NE COAST OF MEXICO FROM TAMPICO TO BROWNSVILLE TEXAS. ISOLATED SHOWERS/THUNDERSTORMS OVER THE BAY OF CAMPECHE S OF 20N. AN UPPER HIGH IS TO THE E OF THE SURFACE LOW JUST N OF THE YUCATAN CHANNEL NEAR 23N86W ENHANCING THE ACTIVITY MENTIONED IN THE SPECIAL FEATURES. CARIBBEAN SEA... UPPER HIGH JUST N OF THE YUCATAN CHANNEL IS GIVING THE W CARIBBEAN WIDESPREAD CLOUDINESS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MAINLY W OF 82W. AN ELONGATED CUT-OFF UPPER LOW EXTENDS ACROSS PUERTO RICO SW TO NEAR 13N75W. THE ITCZ AXIS CROSSES THE N PORTION OF SOUTH AMERICA...PANAMA...AND COSTA RICA GENERATING CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF 13N FROM 64W-80W. FOR THE MOST PART...DRY STABLE AIR DOMINATES THE REMAINDER OF THE CARIBBEAN WITH SOME WIDELY ISOLATED LOW LEVEL TRADE WIND INDUCED SHOWERS MAINLY E OF 70W. ATLANTIC OCEAN... DEEP LAYERED TROUGH DIPS S OF THE W ATLC N OF 26N W OF 67W WITH A SURFACE TROUGH EXTENDING FROM A WEAK 1009 MB LOW NEAR 33N67W TO 28N76W GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM THE BAHAMAS NEAR 26N78W NE TO BEYOND 32N62W. AN UPPER RIDGE EXTENDS FROM THE UPPER HIGH JUST N OF THE YUCATAN CHANNEL THROUGH THE FLORIDA STRAITS E ALONG 26N68W NARROWING TO 30N60W ENHANCING THE ACTIVITY ABOVE. THE REMAINDER OF THE ATLC IS DOMINATED BY BENIGN UPPER LOW/HIGH/LOW WITH MODERATELY DRY STABLE AIR AND A BROAD SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR 32N33W GIVING THE ATLC E OF 60W FAIR WEATHER CLOUDS AND LITTLE CHANCE OF SHOWER ACTIVITY. $$ WALLACE