760 FXUS64 KFWD 161929 AFDFWD AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 229 PM CDT TUE JUN 16 2015 .AVIATION... FOR THE 18Z TAFS...RAIN SHOWER AND THUNDERSTORM CHANCES ARE HIGH OVER THE NEXT 36 HOURS...BUT TIMING THE ONSET OF PERIODS OF MORE INTENSE AND PERSISTENT RAINFALL IS A SIGNIFICANT SHORT TERM FORECAST CHALLENGE. AT 2 PM...THE CENTER OF TROPICAL STORM BILL WAS SOUTHEAST OF VICTORIA...DIRECTLY OVER THE TEXAS GULF COAST. BILL WAS MOVING SLOWLY TO THE NORTHWEST...AND IS EXPECTED TO CONTINUE TO MOVE NORTHWEST UNTIL IT CROSSES OVER THE I-35 CORRIDOR LATE THIS EVENING. AFTER MIDNIGHT...BILL IS EXPECTED TO MOVE NORTH...AND REMAIN WEST OF THE I-35 CORRIDOR. THE RAIN BANDS ASSOCIATED WITH BILL ARE EXPECTED TO BEGIN TO DIRECTLY IMPACT THE WACO AREA A COUPLE OF HOURS AFTER MIDNIGHT...AND THEN IMPACT THE DFW AREA EARLY WEDNESDAY MORNING. THESE TROPICAL RAIN BANDS NEAR BILL ARE EXPECTED TO BE FAIRLY INTENSE...AND SHOULD CAUSE IFR FLIGHT CONDITIONS AND RESULT IN STRONG LOW-LEVEL WIND SHEAR. WENT AHEAD AND MENTIONED LOW-LEVEL WIND SHEAR IN THE TAF WHEN INTENSE RAIN BANDS LOOK MOST LIKELY TO IMPACTS AREA AIRPORTS. THIS WILL HAVE TO BE ADJUSTED BASED ON THE ACTUAL POSITION AND SPEED OF BILL...AND WILL HAVE TO AMEND TAFS THROUGH THIS EVENING ADAPTING TO THE LATEST SPEED AND POSITION OF BILL. ASIDE FROM THE DIRECT IMPACTS OF BILL...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO OCCUR ON AND OFF THROUGHOUT THE NEXT 36 HOURS. HAVE EITHER RAIN OR THUNDER IN ALL HOURS OF THE FORECAST AS A RESULT. WHEN STRONGER RAIN BANDS MOVE OVER AN AIRPORT...RAINFALL RATES WILL LIKELY INCREASE TO 2 INCHES PER HOUR WITH ANY STORM. TROPICAL RAIN BANDS NEAR THE CENTER OF BILL MAY PRODUCE RAINFALL RATES AS HIGH AS 3-4 INCHES PER HOUR. IF BILL IS OVER THE RED RIVER BY LATE WEDNESDAY AFTERNOON...THE INTENSITY AND COVERAGE OF RAIN SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO TAPER OFF. CAVANAUGH && .UPDATE... ...TROPICAL STORM BILL WILL BRING MAJOR FLOODING AND TORNADOES TO NORTH AND CENTRAL TEXAS... IN MY 26 YEAR CAREER IN NORTH TEXAS...THIS IS THE SECOND TIME TO WITNESS A MAJOR RAIN EVENT WHILE AREA LAKES ARE FILLED TO CAPACITY. THE LAST TIME WAS MAY OF 1990...AND IT PRODUCED SIGNIFICANT FLOODING THROUGHOUT A LARGE PORTION OF THE REGION. DALLAS TRINITY PEAKED AT 47.10 FEET ON MAY 3...WHICH IS THE SECOND HIGHEST PEAK AFTER MAY OF 1908 (52.60 FEET). NOT TO SAY THAT THIS EVENT WILL EXCEED THE ABOVE LEVELS...BUT WE FEEL THIS EVENT WILL PRODUCE WIDESPREAD 3-6 INCHES WITH SOME LOCATIONS RECEIVING 6-12 INCHES BEFORE ENDING. AREA LAKES...ESPECIALLY ON THE TRINITY...WILL EXPERIENCE INFLOWS THAT FAR EXCEED THEIR RELEASE POTENTIAL...THUS FORCING MANY RIVERS BACK INTO MAJOR FLOOD FOR THE REST OF THE WEEK AND INTO NEXT WEEK. WITH SUCH HEAVY RAINFALL FORECAST ALONG AND EAST OF THE I-35/35W CORRIDOR THROUGH THURSDAY...WIDESPREAD FLASH FLOODING IS ALSO EXPECTED. RESIDENTS ARE ENCOURAGED TO TAKE ACTION NOW TO PROTECT PROPERTY AND HAVE AN EVACUATION PLAN IN PLACE IF FLASH FLOODING OCCURS. ANOTHER THREAT FROM THIS TROPICAL SYSTEM WILL BE TROPICAL TORNADOES. THIS THREAT WILL INCREASE DURING THE AFTERNOON HOURS WITH A LARGER THREAT DURING THE OVERNIGHT HOURS AS THE REMNANTS OF BILL MOVE NORTHWARD JUST WEST OF I-35. HELICITY VALUES INCREASE IN THE 0-3KM 250-450 M2/S2 RANGE BY LATE EVENING ON THE NORTH THROUGH EAST SIDE OF LOW LEVEL CIRCULATION. THERE WILL BE LITTLE LOSS OF HELICITY OVERNIGHT AND ON WEDNESDAY MORNING AS BILL CONTINUES TO MOVE NORTHWARD THROUGH THE CWA. HAVE INCREASED WINDS ASSOCIATED WITH BILL FOR TONIGHT THROUGH THURSDAY. LEFT POPS MOSTLY AS IS AND ADJUSTED HIGH TEMPERATURES DOWN A DEGREE OR TWO FOR THIS AFTERNOON. 75 && .PREV DISCUSSION... /ISSUED 344 AM CDT TUE JUN 16 2015/ THE MAIN WEATHER STORY FOR TEXAS DURING THE NEXT COUPLE OF DAYS WILL BE TROPICAL STORM BILL. BILL WILL CONTINUE TO MOVE NORTHWEST AROUND THE PERIPHERY OF AN UPPER LEVEL HIGH CENTERED OVER THE SOUTHEASTERN UNITED STATES. THUS THE TROPICAL STORM WILL MAKE LANDFALL ACROSS THE TEXAS COASTAL BEND LATER THIS MORNING AND WEAKEN TO A TROPICAL DEPRESSION OVERNIGHT TONIGHT. ALTHOUGH THE SURFACE CIRCULATION WILL BECOME DIFFUSE TOMORROW MORNING AFTER IT MOVES INTO THE SOUTHWESTERN PART OF THE FORECAST AREA...THE 500 MB LOW WILL LIFT NORTHWARD ACROSS THE AREA JUST WEST OF THE I-35 CORRIDOR WEDNESDAY. THE LOW WILL THEN INTO MOVE NORTHEAST ACROSS OKLAHOMA OVERNIGHT WEDNESDAY NIGHT AND THURSDAY. YESTERDAY AFTERNOON...WE ISSUED A FLASH FLOOD WATCH FOR THE ENTIRE FORECAST AREA THAT GOES INTO EFFECT AT 7 AM TODAY AND GOES THROUGH 7 PM THURSDAY. RATHER THAN TRY TO BREAK THE WATCH INTO SEGMENTS FOR TIMING PURPOSES...WILL LEAVE IT AS IS. WIDESPREAD 4 INCH PLUS RAINFALL TOTALS ARE EXPECTED ALONG AND EITHER SIDE OF THE I-35 CORRIDOR WITH 2 TO 4 INCHES EXPECTED ACROSS THE EASTERN-MOST ZONES..AND 1 TO 3 INCHES ACROSS THE WESTERN-MOST ZONES. BESIDES THE THREAT FOR FLASH FLOODING...THERE WILL BE THE POTENTIAL FOR SOME TROPICAL TORNADOES TODAY AND TOMORROW WITH THE INCREASED SHEAR. HIGH RAIN CHANCES WILL CONTINUE ON THURSDAY BUT WILL SLOWLY SHIFT EASTWARD AS THE UPPER LEVEL LOW MOVES OFF TO THE NORTHEAST. AN UPPER LEVEL RIDGE WILL START TO BUILD IN FROM THE WEST FRIDAY. HAVE KEPT SOME LOW POPS ACROSS THE WEST INTO FRIDAY...WITH CHANCE POPS ALONG AND EAST OF I-35. HAVE ALSO PLACED SOME LOW POPS ACROSS THE SOUTHEAST SATURDAY AFTERNOON AND SOUTH SUNDAY AFTERNOON FOR SOME DIURNALLY DRIVEN CONVECTION. AS A SHORTWAVE MOVES SOUTHEAST ACROSS THE PLAINS AROUND THE PERIPHERY OF AN UPPER LEVEL RIDGE SUNDAY NIGHT...THERE MAY BE A LOW CHANCE OF STORMS NEAR THE RED RIVER...THUS HAVE INTRODUCED SOME 20 PERCENT POPS FOR THEN. OTHERWISE... IT LOOKS DRY FOR THE BEGINNING OF NEXT WEEK WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 73 81 73 84 / 80 100 100 70 70 WACO, TX 84 74 83 74 85 / 90 100 90 70 70 PARIS, TX 83 72 82 72 83 / 80 90 100 70 70 DENTON, TX 82 72 80 72 84 / 80 100 100 70 70 MCKINNEY, TX 83 72 81 72 83 / 80 100 100 70 70 DALLAS, TX 83 73 82 74 84 / 80 100 100 70 70 TERRELL, TX 84 73 82 73 84 / 80 100 100 70 70 CORSICANA, TX 84 74 81 73 83 / 80 100 100 70 70 TEMPLE, TX 84 72 83 73 85 / 90 100 90 70 70 MINERAL WELLS, TX 81 71 80 70 85 / 80 100 100 60 50 && .FWD WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR TXZ091>095- 100>107-115>123-129>135-141>148-156>162-174-175. && $$