FXUS64 KCRP 112333 AAA AFDCRP AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 533 PM CST THU MAR 11 2010 .DISCUSSION...SEE AVIATION DISCUSSION FOR 00Z TAFS. && .AVIATION...ONLY MAJOR ISSUE IS WHETHER MOISTURE WILL COME BACK FAR ENOUGH EAST TO IMPACT KCRP AND KVCT AREAS SO THAT FOG MAY FORM. AT THIS TIME...BASED ON LATEST OBSERVATIONS (WITH KNGP ALREADY BELOW IFR VISIBILITIES)...FOG WILL ROLL INTO KCRP BUT NOT INTO KVCT WHICH IS CLOSER TO THE WINDSHIFT BOUNDARY AND DRIER AIR. ONCE WIND SHIFT MOVES THROUGH AROUND 03Z...FOG WILL GO AWAY AND VFR CONDITIONS ARE EXPECTED AREA-WIDE. ALSO...SEA-BREEZE BOUNDARY COULD GET INTO KALI BEFORE BOUNDARY SHIFTS WINDS BACK TO NORTH...SO DO HAVE A BRIEF WIND SHIFT BEFORE WINDS COME BACK TO NORTH AND STRENGHTEN. HOWEVER...DO NOT EXPECT FOG TO GET THAT FAR WEST. MAY HAVE A FEW WIND GUSTS AROUND 20 KNOTS BEHIND BOUDNARY BUT OVERALL SUSTAINED WIND FORECAST WILL DO. && .PREV DISCUSSION... /ISSUED 358 PM CST THU MAR 11 2010/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...A POTENT S/WV WL SWING THROUGH THE CWA TNT. THIS WL PRODUCE A DEEPENING NORTHWEST FLOW AND EVEN MORE SUBSIDENCE TO AFFECT THE CWA. LIMITED MOISTURE MOSTLY IN THE MID LVLS WL PRECLUDE THE MENTION OF PCPN. STRONG NVA AND SUBSIDENCE WL THEN PREVAIL THROUGH THE REMAINDER OF THE FCST AS STRONG RIDGING AT ALL LVLS BUILDS INTO THE CWA. THE MAIN EFFECT FROM THIS TROUGH PASSAGE WL BE A COOLDOWN...ESPECIALLY ON THE OVERNIGHT LOWS WHERE TEMPS WL BE AT LEAST 15 DEGREES COOLER THAN THEY HAVE BEEN IN RECENT DAYS. THERE WL BE A BRIEF WINDOW EARLY THIS EVENING FOR THE IMMEDIATE COASTAL AREAS TO EXPERIENCE FOG GIVEN THE FLAT GRADIENT AND LIGHT SEA BREEZE. HOWEVER...GIVEN THE EXPECTED SHORT DURATION OF THIS EVENT...AN ADVY IS NOT ANTICIPATED ATTM. MARINE...WIDESPREAD SEA FOG WL PERSIST THIS EVENING ACROSS MOST OF THE NEARSHORE AND OFFSHORE WATERS. THE FLAT GRADIENT AND VERY POOR MIXING HAS PREVENTED THIS FOG FROM DISSIPATING THAT MUCH TDA. SINCE THIS WK GRADIENT WL LKLY PERSIST THROUGH AT LEAST EARLY THIS EVENING...DECIDED TO ISSUE ANOTHER DENSE FOG ADVY FOR THE MARINE AREAS. BY 02-03Z...THE WINDS WL BEGIN TO INCREASE FROM THE NORTHWEST AS THE SFC HIGH PRESSURE WEDGE BEGINS TO BUILD IN FROM THE WEST DUE TO THE APPROACHING S/WV. AS A RESULT...THE FOG SHOULD BEGIN TO DISSIPATE AND MOVE FURTHER OFFSHORE BY THIS TIME FRAME. SCA CONDITIONS ARE EXPECTED AS EARLY AS 07-08Z FRI OVER THE OFFSHORE WATERS AS THE GRADIENT AND CAA REALLY INTENSIFIES. SCA CONDITIONS WL PERSIST THROUGH FRI MORNING AND THEN WEAKEN SIGNIFICANTLY BY FRI AFTN/EVE AS THE GRADIENT FLATTENS OUT. A QUICK RETURN TO ONSHORE FLOW IS EXPECTED BY MIDNIGHT FRI AS WINDS RESPOND TO A BROAD LOW PRESSURE AREA SPINNING OVER THE TN/OH VLY RGN. LONG TERM (SATURDAY THROUGH THURSDAY)...THE DRY/SUBSIDENT AIRMASS OVER SOUTH TEXAS WILL GRADUALLY SHIFT INTO THE WESTERN GULF LATE SATURDAY. DOWNSLOPE FLOW WILL ALLOW AFTERNOON HIGHS TO REACH THE UPPER 80S WEST...TO THE UPPER 70S ACROSS THE VICTORIA CROSSROADS. ONSHORE FLOW WILL DEVELOP SATURDAY NIGHT INTO SUNDAY AHEAD OF A SURFACE LOW DEVELOPING ACROSS WEST TEXAS...AHEAD OF AN UPPER LOW APPROACHING FROM THE FOUR CORNERS REGION. THE MEDIUM RANGE MODELS CONTINUE TO PROG THE UPPER LOW TO DIVE INTO THE BIG BEND AREA MONDAY. AS IT DOES...MOISTURE RETURN/ISENTROPIC UPGLIDE WILL COMMENCE ALONG AND WEST OF THE RIO GRANDE...GENERATING A SLIGHT CHANCE OF LIGHT RAIN WEST OF THE I-35 CORRIDOR MONDAY MORNING. INCREASING DYNAMICS ALOFT COMBINED WITH A 500MB JET STREAK NOSING INTO THE WESTERN PORTIONS OF THE CWA SHOULD ALLOW FOR STRATIFORM PRECIP TO TRANSITION TO CONVECTIVE ACTIVITY MONDAY AFTERNOON. THE LATEST GFS KEEPS THE DEEPEST MOISTURE/HIGHEST PRECIP CHANCES CONFINED TO THE WESTERN AREAS AS THE LOW SWINGS ACROSS SOUTH TEXAS MONDAY NIGHT/TUESDAY. HOWEVER...THE LATEST ECMWF IS CONSISTENT WITH THE PREVIOUS FORECAST SHOWING PRECIP OVERSPREADING THE CWA FROM WEST TO EAST DURING THE MONDAY NIGHT/TUESDAY PERIOD. WILL CONTINUE TO FORECAST THE ECMWF SOLUTION FOR THIS RAIN EVENT AS UPPER DYNAMICS ARE EXPECTED TO BE SUFFICIENT TO GENERATE CONVECTION ACROSS SOUTH TEXAS. THE UPPER LOW WILL GENERATE A COASTAL TROUGH WELL SOUTH OF THE REGION. NORTHERLY WINDS WILL DEVELOP AREAWIDE TUESDAY AS THE COASTAL TROUGH ENTERS THE WESTERN GULF. HIGHS TUESDAY WILL BE BELOW NORMAL GIVEN THE CAA AND CLOUD COVER. CONDITIONS SHOULD DRY OUT BY WEDNESDAY...AND WILL CONTINUE INTO THURSDAY AS HIGH PRESSURE BUILDS INTO SOUTH TEXAS. TEMPERATURES SHOULD BEGIN A GRADUAL WARMING TREND AS WELL. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 48 76 46 81 50 / 0 0 0 0 0 VICTORIA 43 73 42 78 46 / 0 0 0 0 0 LAREDO 49 81 49 88 55 / 0 0 0 0 0 ALICE 46 78 44 84 47 / 0 0 0 0 0 ROCKPORT 48 74 48 75 53 / 0 0 0 0 0 COTULLA 43 77 41 84 47 / 0 0 0 0 0 KINGSVILLE 47 78 44 86 47 / 0 0 0 0 0 NAVY CORPUS 51 74 51 75 56 / 0 0 0 0 0 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...RED FLAG WARNING UNTIL 9 PM CST THIS EVENING FOR THE FOLLOWING ZONES: LA SALLE...WEBB. GM...DENSE FOG ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM CST FRIDAY FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ GW/86...AVIATION/MESO SC/70...SYNOPTIC/GRIDS WWWW