Scientific Forecaster Discussion
000 FXUS64 KFWD 161834 AAA AFDFWD Area Forecast Discussion...UPDATED National Weather Service Fort Worth TX 134 PM CDT Thu Aug 16 2018 .AVIATION... 18 UTC TAFs Concerns---Potential for showers and storms in the vicinity of Metroplex terminals on Friday. Otherwise, VFR. VFR is expected to prevail through the entire TAF cycle with generally south flow. Convection is expected to develop late this evening and into the overnight hours along the Red River which could cause some issues for northbound departures and arrivals from the Bowie and Bonham cornerposts. This activity may slide southward toward the I-20 corridor, but the decreasing wind field aloft should ensure that showers/storms will be on the decline. For now, I'll advertise VCSH that could impact the Friday morning push from 11 to 15 UTC at the Metroplex. Convective outflow could result in a deviation from the southerly flow currently advertised in the TAF. The predictability of these potential boundaries is too low to include in the TAF at this time. There should be a lull in convective coverage through the noontime hour with reinvigorated convection in the early to mid afternoon across North Texas. Confidence is high enough to include a VCTS group in the extended portion of the D/FW TAF between 18 and 22 UTC Friday. Storms may produce gusty winds and heavy rain which may result in restricted visibility. Waco will remain unaffected by showers or thunderstorms...unless activity develops earlier and farther south than currently expected. VFR should prevail, though MVFR stratus may attempt to make another run at the terminal on Friday morning. Bain && .SHORT TERM... /Issued 402 AM CDT Thu Aug 16 2018/ /Today and Tonight/ A shortwave is currently moving east-southeast across the Texas Panhandle and helping to maintain an area of showers and thunderstorms northwest of the CWA early this morning. Chances are that this area of convection will dissipate before reaching North Texas, but we will keep less than 20 POPs along the Red River for the outside chance of an isolated storm later today. Meanwhile, an upper low can be seen on satellite moving east across Nebraska. A second disturbance is progged to swing around the southwest portion of the upper low tonight, generating another round of showers and storms to our northwest. It looks like this activity will occur a little farther south, warranting slight chance POPs roughly along and north of the Highway 380 corridor for tonight. Otherwise, the primary concern will be the hot weather still expected across the region. The good news is that debris from upstream convection will keep temperatures slightly lower than what we were expecting this time yesterday. Still, heat index values from 100 to 104 will likely be experienced for all but the southwest counties, where drier air will knock a few degrees off apparent temperatures. && .LONG TERM... /Issued 402 AM CDT Thu Aug 16 2018/ /Friday through Next Week/ The passing shortwave will force a weak front southward to near the Red River on Friday. There should be enough lift generated by the northwest flow aloft over the Southern Plains to ignite scattered thunderstorms in the vicinity of the front during peak heating hours Friday. Storms will likely remain scattered in nature, but should generate enough mid and high cloud cover to keep temperatures and heat indices below heat advisory criteria, though again 100-104 apparent temperatures will be fairly common. A few of the storms Friday afternoon and evening will be capable of gusty winds and hail due to the enhanced shear provided by the northwest flow. Thunderstorm chances will continue over the weekend along the Red River due to the presence of the lingering boundary, good diurnal instability and modest shear. The better chances for storms will occur along the Red River with slight chance POPs extending as far south as I-20. A strong shortwave trough will then travel southeast through the Southern and Central Plains Sunday and Sunday night, sending a cold front south of the Red River and bringing better chances for showers and thunderstorms to the region. The strongest upper level forcing will occur Sunday evening, which is when the better storm chances and potential for strong to possibly severe storms will occur. Severe weather would not be widespread, but instability and shear should be enough for at least an outside chance for a damaging wind gust. A chance of storms will linger through midweek as the boundary becomes stationary over the area, but upper level forcing will be weak and coverage isolated. 30 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 97 80 98 78 98 / 5 10 10 10 10 Waco 98 77 99 77 99 / 5 5 5 5 5 Paris 95 76 96 75 95 / 10 20 30 30 30 Denton 96 78 97 77 98 / 10 20 20 20 20 McKinney 96 78 97 77 98 / 10 10 20 20 20 Dallas 98 80 98 80 98 / 5 10 10 10 10 Terrell 96 77 98 77 97 / 10 10 10 10 10 Corsicana 97 77 98 78 97 / 5 5 10 5 5 Temple 98 76 99 76 99 / 5 5 0 5 5 Mineral Wells 96 76 97 75 97 / 5 10 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... None.