000 AXNT20 KNHC 290003 CCA TWDAT TROPICAL WEATHER DISCUSSION...UPDATED NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUN 28 2010 UPDATED FOR TROPICAL STORM ALEX CURRENT LOCATION AND TIME 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2245 UTC... ...SPECIAL FEATURES... TROPICAL STORM ALEX IS CENTERED NEAR 20.6N 91.6W AT 28/0000 UTC...ABOUT 525 MILES SE OF BROWNSVILLE TEXAS...OR 420 MILES ESE OF TAMPICO MEXICO MOVING NNW AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB WITH MAXIMUM SUSTAINED WINDS OF 50 KT WITH GUSTS TO 60 KT. TROPICAL STORM AND HURRICANE WATCHES ARE IN EFFECT FOR PORTIONS OF NE MEXICO AND SE TEXAS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. THIS SYSTEM CONTINUES TO DRAW A SIGNIFICANT AMOUNT OF DEEP LAYER MOISTURE ACROSS THE GULF OF MEXICO GENERATING NUMEROUS STRONG CONVECTION FROM 19N-23N BETWEEN 87W-91W AFFECTING THE YUCATAN PENINSULA...FROM 19N-21N BETWEEN 91W-92W NEAR THE CENTER FIX...AND FROM 22N-25N BETWEEN 91W-94W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 24N-32N BETWEEN 81W-90W COVERING MUCH OF THE ERN HALF OF THE GULF OF MEXICO. SIMILAR ACTIVITY IS ALSO IMPACTING CUBA...AND SE MEXICO FROM 17N-21N BETWEEN 92W-97W. DUE TO THE LARGE AMOUNT OF RAINFALL ACCUMULATED OVER THE PAST FEW DAYS OVER THESE AREA...THE THREAT FOR FLASH FLOODING AND MUDSLIDES IS STILL HIGH ON AREAS WHERE THE TERRAIN HAS BECOME SATURATED ESPECIALLY OVER THE YUCATAN PENINSULA AND SE MEXICO. ALEX IS EXPECTED TO INCREASE IN FORWARD SPEED TO THE NW. ALEX IS ALSO FORECAST TO STRENGTHEN TO HURRICANE FORCE WITHIN THE NEXT 24 HRS. ...TROPICAL WAVES... TROPICAL WAVE IS APPROACHING THE AFRICAN COAST ALONG 18N14W 6N15W MOVING W 15-20 KT. SCATTERED STRONG CONVECTION IS FROM 10N-14N BETWEEN 10W-18W. UPPER-AIR TIME SECTION ANALYSIS FROM DAKAR SENEGAL INDICATES A LOW-LEVEL DRY VORTICITY CENTER PASSING THE STATION AROUND 28/1200 UTC WHICH PRECEDES THE WAVE AXIS. TROPICAL WAVE IS ALONG 43W S OF 13N MOVING W NEAR 10 KT. LOW-LEVEL CYCLONIC FLOW IS ABOUT THE WAVE AXIS CONCENTRATED S OF 10N. THE WAVE IS ALSO W OF A SURGE OF RELATIVE ENHANCED MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE/STRONG CONVECTION IS FROM EQ-6N BETWEEN 40W-47W...AND FROM 8N-10N BETWEEN 42W-45W. TROPICAL WAVE EXTENDS FROM 16N79W TO 8N83W MOVING W NEAR 15 KT. WAVE IS FOLLOWING A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY SEEN ACROSS THE WRN HALF OF THE CARIBBEAN. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 14N-19N BETWEEN 77W-81W...AND FROM 9N-12N BETWEEN 82W-86W ACROSS COSTA RICA. THE WAVE MAY ALSO BE ENHANCING SOME OF THE CONVECTION SEEN ACROSS CUBA. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N16W 4N29W 5N44W 5N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM N...AND 200 NM S OF THE AXIS BETWEEN 23W-40W. SIMILAR ACTIVITY IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 47W-60W. ...DISCUSSION... GULF OF MEXICO... SIGNIFICANT MOISTURE ASSOCIATED WITH TROPICAL STORM ALEX IS BEING DRAWN ACROSS MUCH OF THE GULF OF MEXICO SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE MAJORITY OF THE BASIN. ALEX IS CURRENTLY IN THE SE BAY OF CAMPECHE PRODUCING STRONG SHOWERS/THUNDERSTORMS FROM 19N-23N BETWEEN 87W-91W ACROSS THE YUCATAN PENINSULA...FROM 19N-21N BETWEEN 91W-92W NEAR THE CENTER OF THE SYSTEM...AND FROM 22N-25N BETWEEN 91W-94W. SCATTERED SHOWERS/THUNDERSTORMS ARE E OF 91W INCLUDING MUCH OF SE LOUISIANA...AND THE FLORIDA PENINSULA. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. ALOFT...UPPER LEVEL RIDGING EXTENDS FROM CENTRAL MEXICO TO ERN TEXAS WITH A SHORTWAVE UPPER LEVEL TROUGH TO ITS IMMEDIATE E ACROSS LOUISIANA. AN UPPER LEVEL RIDGE COVERS THE ERN HALF OF THE BASIN. THE SHORTWAVE UPPER TROUGH IS FORECAST TO MOVE EWD ALLOWING UPPER LEVEL RIDGING TO BUILD ACROSS THE NRN GULF WHICH WILL HELP STEER ALEX TOWARD THE NW. EXPECT CONTINUED SHOWER ACTIVITY ACROSS MUCH OF THE BASIN AS MOISTURE WITH ALEX REMAINS ACROSS THE AREA. FOR MORE INFORMATION AND UPDATES REGARDING ALEX...VISIT OUR WEBPAGE AT WWW.NHC.NOAA.GOV. CARIBBEAN SEA... MOISTURE ASSOCIATED WITH TROPICAL STORM ALEX...AND A TROPICAL WAVE FROM 16N79W TO 8N83W CONTINUES TO AFFECT THE NW CARIBBEAN SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE MAJORITY OF CUBA...FROM 14N-19N BETWEEN 77W-81W IN THE NW CARIBBEAN...AND FROM 9N-12N BETWEEN 82W-86W ACROSS COSTA RICA. SCATTERED SHOWERS/THUNDERSTORMS HAVE ALSO FLARED UP OVER NRN HISPANIOLA MOST LIKELY ENHANCED BY THE COMBINATION OF DAYTIME HEATING AND UPPER LEVEL SUPPORT FROM AN UPPER LEVEL LOW SPINNING N OF TURKS AND CAICOS NEAR 25N72W. THE REMAINDER OF THE CENTRAL AND ERN CARIBBEAN IS INFLUENCED BY DRY AIR ALOFT KEEPING CONDITIONS FAIR. ALOFT...NLY FLOW COVERS THE WRN HALF OF THE BASIN AROUND AN UPPER LEVEL RIDGE EXTENDING FROM THE ERN GULF OF MEXICO WITH WEAK UPPER TROUGHING COVERING THE ERN HALF OF THE BASIN EXTENDING FROM THE AFOREMENTIONED UPPER LEVEL LOW NEAR 25N72W. DIFFLUENCE ALOFT BETWEEN THESE TWO FEATURES MAY BE ENHANCING CONVECTION OVER NRN VENEZUELA S OF 13N BETWEEN 68W-73W. EXPECT MOISTURE AND WINDY CONDITIONS TO REMAIN ACROSS THE NW CARIBBEAN INFLUENCED BY TROPICAL STORM ALEX AND THE TROPICAL WAVE MOVING ACROSS THE NW CARIBBEAN. ATLANTIC OCEAN... A SURFACE TROUGH IS N OF ERN HISPANIOLA ALONG 68W FROM 21N-26N SUPPORTED BY A MID-UPPER LEVEL LOW NEAR 25N72W. POSSIBLE ISOLATED SHOWERS ARE FROM 19N-27N BETWEEN 61W-74W. A SECOND SURFACE TROUGH IS ALONG 57W FROM 21N-26N ENHANCING ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE AXIS. ELSEWHERE ACROSS THE ATLANTIC...A BROAD SURFACE RIDGE DOMINATES ANCHORED BY A 1030 MB AZORES HIGH NEAR 35N35W KEEPING CONDITIONS FAIR ACROSS THE BASIN. ALOFT...WATER VAPOR IMAGERY INDICATES A DRY AND STABLE AIRMASS ACROSS THE AREA FURTHER SUPPORTING THE FAIR WEATHER. AN UPPER LEVEL RIDGE EXTENDS ALONG 60W E OF THE AFOREMENTIONED UPPER LEVEL LOW WITH A BROAD UPPER LEVEL TROUGH COVERING THE REMAINDER OF THE AREA EXTENDING FROM THE AZORES ISLANDS TO NEAR 16N40W. 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