FXUS64 KFWD 152031 AFDFWD AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FORT WORTH TX 331 PM CDT MON JUN 15 2015 .SYNOPSIS... AN ACTIVE WEEK OF WEATHER IS ON TAP FOR NORTH AND CENTRAL TEXAS. THE TROPICAL SYSTEM IN THE GULF CONTINUES TO BECOME BETTER ORGANIZED AND IS SET TO IMPACT OUR AREA BEGINNING ON TUESDAY AND LASTING POSSIBLY THROUGH THURSDAY. WIDESPREAD HEAVY RAIN LEADING TO FLOODING WILL BE THE MAIN CONCERN WITH THIS SYSTEM...AND AS A RESULT... A FLASH FLOOD WATCH IS BEING ISSUED WITH THIS FORECAST PACKAGE AREA-WIDE FROM TUESDAY MORNING THROUGH THURSDAY EVENING. && .SHORT TERM... SCATTERED SHOWERS AND STORMS HAVE DEVELOPED ACROSS MUCH OF THE AREA AGAIN TODAY WITH AN UNCAPPED UNSTABLE AIR MASS IN PLACE. STRONGER UPPER FORCING COUPLED WITH A REMNANT MCV HAVE LED TO INCREASED COVERAGE OF SHOWERS AND STORMS IN OUR WESTERN ZONES. THE MAJORITY OF THIS ACTIVITY WILL BEGIN TO DISSIPATE WITH LOSS OF DAYTIME HEATING BUT A FEW ISOLATED SHOWERS AND STORMS WILL STILL BE POSSIBLE OVERNIGHT. DESPITE RELATIVELY LIGHT APPEARANCE ON RADAR REFLECTIVITY...THESE SHOWERS AND STORMS HAVE BEEN EFFICIENT RAINFALL PRODUCERS WITH SOME SITES PICKING UP A QUICK 0.10 TO 0.20 INCHES OF RAIN. THIS IS NOT SURPRISING GIVEN THE VERTICAL PROFILE IN PLACE SHOWN BY OUR MORNING SOUNDING WITH PRECIPITABLE WATER VALUES ALREADY IN EXCESS OF 2 INCHES AND A DEEP WARM CLOUD DEPTH. THERE IS STILL UNCERTAINTY REGARDING THE TRACK AND TIMING OF OUR UNNAMED TROPICAL SYSTEM...AND THEREFORE WILL AVOID DELVING INTO SPECIFIC TIMING/LOCATION IMPACTS...BUT IT DOES APPEAR SET TO MAKE LANDFALL ON TUESDAY MORNING ALONG THE TEXAS COAST. LATEST MODEL GUIDANCE HAS BEEN CONVERGING TOWARD A SLOWER AND MORE WESTWARD TRACK WHICH WOULD TAKE THE LOW PRESSURE CENTER WEST OF THE I-35 CORRIDOR. GIVEN THIS SOLUTION...THIS IMPLIES THE HEAVIEST RAIN AXIS WILL BE NEAR THE I-35 CORRIDOR WITH A FAIRLY LARGE EAST-WEST BUFFER AREA. RAIN AND STORMS WILL DEVELOP AND ARRIVE AS MULTIPLE BANDS OF CONVECTION BEGINNING ON TUESDAY MORNING OR EARLY AFTERNOON. COVERAGE AND INTENSITY WILL GENERALLY BE ON THE INCREASE THROUGH TUESDAY EVENING AND WILL BEGIN TO DIMINISH OVERNIGHT. HEAVY RAINFALL IS CERTAINLY STILL A POSSIBILITY OVERNIGHT...BUT OVERALL COVERAGE AND INTENSITY WILL LIKELY BE LESS DURING THIS TIME. ALL RAIN SHOWERS AND THUNDERSTORMS WILL BE REMARKABLY EFFICIENT RAIN PRODUCERS WITH ALL GUIDANCE POINTING TOWARD PRECIPITABLE WATER VALUES NEAR 2.5 INCHES BY TUESDAY AFTERNOON/EVENING WITH THE COLUMN SATURATED TO 300MB. IT WILL NOT TAKE LONG FOR LOCATIONS TO PICK UP IMPRESSIVE RAINFALL TOTALS...AND AS A RESULT...FLOODING ISSUES ARE LIKELY TO BE REAGGRAVATED IN MANY LOCATIONS THROUGH THE MIDDLE OF THE WEEK. FLASH FLOODING WILL BE LIKELY WHERE CELL TRAINING OCCURS. MOST GUIDANCE SHOWS THE LOW PRESSURE CENTER NEAR OUR SOUTHEAST ZONES BY WEDNESDAY MORNING. ADDITIONAL WIDESPREAD CONVECTION IS EXPECTED THROUGHOUT THE DAY ON WEDNESDAY AS OUR ENTIRE CWA REMAINS IN A FAVORABLE ZONE FOR TROPICAL CONVECTION. THE HEAVIEST AND MOST WIDESPREAD RAINFALL IS LIKELY TO OCCUR ON WEDNESDAY AS THE LOW PRESSURE CENTER TRAVERSES OUR CWA FROM SOUTH TO NORTH. SUBSTANTIAL DIFFERENCES IN GUIDANCE BEGIN TO OCCUR BY LATE WEDNESDAY REGARDING THE SPEED OF THIS SYSTEM AS IT CONTINUES TO PUSH NORTHWARD. WITH RELATIVELY WEAK FLOW ALOFT...THERE IS NOT A STRONG MECHANISM TO USHER THIS SYSTEM OUT OF OUR AREA. INSTEAD IT WILL BE FORCED TO ROUND THE RIDGE POSITIONED OVER THE SOUTHEASTERN CONUS BEFORE BECOMING INGESTED IN THE STRONGER UPPER FLOW WHICH IS DISPLACED WELL TO THE NORTH. AS A RESULT...WE HAVE CARRIED THE FLASH FLOOD WATCH THROUGH THURSDAY EVENING SINCE IT IS POSSIBLE LINGERING CONVECTION FROM THIS SYSTEM WILL STILL BE IMPACTING PORTIONS OF OUR CWA. CHANGES CAN AND WILL BE MADE TO THE CURRENT FORECAST AS NEW DATA IS ACQUIRED AND ANALYZED...BUT THESE ARE SOME OF THE EXPECTATIONS AT THE CURRENT TIME. WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES ACROSS THE CWA ARE LIKELY BY THURSDAY EVENING. AN AXIS OF 2-4 INCHES IS POSSIBLE NEAR THE I-35 CORRIDOR...OR JUST EAST OF WHERE THE LOW PRESSURE CENTER WILL TRACK. IT IS ALSO POSSIBLE THAT SOME VERY LOCALIZED AREAS THAT EXPERIENCE MULTIPLE STRONGER STORMS PICK UP AMOUNTS MUCH HIGHER THAN 4 INCHES IN OUR CWA...BUT DO NOT HAVE THE CONFIDENCE TO ADVERTISE ANY SPECIFIC LOCATIONS OR SPECIFIC HIGHER AMOUNTS AT THIS TIME. ONE THREAT THAT CANNOT BE OVERLOOKED ON TUESDAY AND WEDNESDAY IS THE TROPICAL CYCLONE /TC/ TORNADO THREAT. THE THREAT FOR TC TORNADOES IS HIGHEST IN THE RIGHT-FRONT QUADRANT WITH RESPECT TO THE TC MOTION VECTOR...SO GENERALLY NORTHEAST OF THE LOW IN THIS CASE. GIVEN THE CURRENT FORECAST TRACK THIS PLACES THE HIGHEST THREAT ALONG AND EAST OF THE I-35 CORRIDOR...WHICH DOES CURRENTLY APPEAR TO HAVE A TYPICAL TC TORNADO ENVIRONMENT CHARACTERIZED BY TALL THIN CAPE AND STRONG SHEAR YIELDING LOW BULK RICHARDSON NUMBERS. THE MAIN TIME FRAME I AM CONCERNED WITH RIGHT NOW IS TUESDAY AFTERNOON AS SOME OF THE INITIAL OUTER BANDS STREAM NORTHWARD THROUGH THE CWA. THE THREAT FOR LOW-TOPPED SUPERCELLS IS GENERALLY LARGEST IN THE OUTER BANDS WHERE HIGHER INSTABILITY IS POSSIBLE DUE TO THE CHANCES FOR A FEW BREAKS IN THE CLOUDS LEADING TO LARGER SURFACE BASED INSTABILITY. LOW LEVEL SOUTHERLY WIND FIELDS ASSOCIATED WITH THIS SYSTEM MAY BE IN EXCESS OF 50 KTS....AND WHEN COUPLED EASTERLY SURFACE WINDS...WILL CREATE PREFERABLE LOW-LEVEL SHEAR AND LARGE LOOPING HODOGRAPHS WITH 0-3 KM HELICITY VALUES NEAR 300-400 M2/S2. THIS THREAT WILL CERTAINLY BEAR WATCHING ON BOTH TUESDAY AND WEDNESDAY. && .LONG TERM... AS EXPECTED...UNTIL THERE IS A BETTER HANDLE ON THE TRACK AND SPEED OF THE TROPICAL SYSTEM...THERE IS MUCH UNCERTAINTY IN THE EXTENDED FORECAST. SOME LINGERING SHOWERS AND STORMS WILL BE POSSIBLE ON FRIDAY AS AN ELONGATED POSITIVELY TILTED UPPER TROUGH PERSISTS JUST TO OUR WEST. THE GFS IS QUICK TO BUILD IN AN UPPER RIDGE OVER THE WEEKEND CUTTING OFF OUR PRECIP CHANCES WHILE THE ECMWF LINGERS SOME CHANCES FOR RAIN OVER OUR SOUTHEAST ZONES. REGARDLESS...TEMPERATURES SHOULD RETURN TO THE LOW 90S FOR MUCH OF THE AREA BY NEXT WEEKEND WITH MUCH LOWER RAIN CHANCES IN PLACE THAN WHAT WE WILL EXPERIENCE MID-WEEK. STALLEY && .AVIATION... /ISSUED 1250 PM CDT MON JUN 15 2015/ THE PRIMARY AVIATION WEATHER CONCERN THIS AFTERNOON AT ALL NORTH TEXAS TAF SITES WILL BE SCATTERED THUNDERSTORMS. THE MOST FAVORED TIME FOR STORMS WILL BE DURING THE HEAT OF THE AFTERNOON MUCH LIKE THE PAST SEVERAL DAYS. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. LOW LEVEL MOISTURE WILL REMAIN HIGH ACROSS NORTH TEXAS THROUGH THE NIGHT AND THIS WILL RESULT IN A RETURN OF MVFR TO IFR CEILINGS DURING THE OVERNIGHT AND MORNING HOURS TUESDAY. RAIN CHANCES WILL ALSO BE ON THE INCREASE TUESDAY MORNING AS A TROPICAL SYSTEM IN THE GULF MOVES INLAND. A SOUTHEAST WIND THIS AFTERNOON WILL SLOWLY BACK TO THE EAST TUESDAY AS THE TROPICAL LOW MOVES INLAND. WIND SPEEDS WILL RANGE FROM 8 TO 13 KNOTS ALONG WITH SOME HIGHER GUSTS. 79 && .AVIATION... THE PRIMARY AVIATION WEATHER CONCERN THIS AFTERNOON AT ALL NORTH TEXAS TAF SITES WILL BE SCATTERED THUNDERSTORMS. THE MOST FAVORED TIME FOR STORMS WILL BE DURING THE HEAT OF THE AFTERNOON MUCH LIKE THE PAST SEVERAL DAYS. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. LOW LEVEL MOISTURE WILL REMAIN HIGH ACROSS NORTH TEXAS THROUGH THE NIGHT AND THIS WILL RESULT IN A RETURN OF MVFR TO IFR CEILINGS DURING THE OVERNIGHT AND MORNING HOURS TUESDAY. RAIN CHANCES WILL ALSO BE ON THE INCREASE TUESDAY MORNING AS A TROPICAL SYSTEM IN THE GULF MOVES INLAND. A SOUTHEAST WIND THIS AFTERNOON WILL SLOWLY BACK TO THE EAST TUESDAY AS THE TROPICAL LOW MOVES INLAND. WIND SPEEDS WILL RANGE FROM 8 TO 13 KNOTS ALONG WITH SOME HIGHER GUSTS. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 74 86 74 82 74 / 40 70 70 80 80 WACO, TX 72 86 73 82 74 / 50 80 70 80 70 PARIS, TX 72 85 72 82 72 / 40 70 70 80 80 DENTON, TX 73 86 73 79 72 / 40 70 70 80 80 MCKINNEY, TX 72 85 72 84 73 / 40 70 70 80 80 DALLAS, TX 77 86 76 82 75 / 40 70 70 80 80 TERRELL, TX 72 85 73 82 72 / 40 70 70 80 80 CORSICANA, TX 73 85 74 82 73 / 50 80 70 80 70 TEMPLE, TX 71 86 71 82 72 / 50 80 70 80 70 MINERAL WELLS, TX 72 84 70 80 72 / 50 70 70 70 80 && .FWD WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FROM TUESDAY MORNING THROUGH THURSDAY EVENING FOR TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175. && $$ 79/77