387 FXUS64 KFWD 210910 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 410 AM CDT Fri Aug 21 2020 .SHORT TERM... /Issued 1142 PM CDT Thu Aug 20 2020/ /Tonight through Friday night/ A mostly clear sky, dry air and light east to southeast wind will result in a cool night by mid August standards with lows ranging from the mid 60s to the lower 70s. Friday will be another seasonably hot and rain-free day with highs from the lower 90s near the Red River to the upper 90s across parts of Central Texas. Low level moisture will slowly increase across Central Texas through the day, resulting in afternoon heat index values near the century mark. Mid and high clouds will also increase from north to south during the afternoon as a shortwave approaches from the Central Plains. Large scale lift and elevated moisture will accompany the shortwave as it moves south across the region Friday night, bringing a chance for showers and thunderstorms mainly west of the I-35 corridor. We will keep PoPs low (20%-30%) since moisture will be limited to the mid levels. The limited moisture will also keep rain amounts generally less than 1/4 inch. Temperatures Friday night will be a bit warmer than the past several nights due to the increase in cloud cover and a gradual return of low level moisture. Lows will range from the upper 60s to the mid 70s. 79 && .LONG TERM... /NEW/ /This Weekend Through Next Week/ Showers and thunderstorms may be ongoing at daybreak Saturday morning as the final and most significant impulse embedded in northerly flow aloft dives into North Texas. Even though the event is only 24 hours away, CAMs are struggling to resolve this elevated activity, which they are wont to do. In their defense, this is a challenging scenario, with persistent mid-level moist advection to our west immediately adjacent to the dry slot on the back side of a decaying cyclone over the Lower Mississippi Valley. This means our western zones will be favored, but the eastern extent of the activity may bleed east of the I-35 corridor, particularly during the daylight hours of Saturday morning when the shortwave will steadily push the moisture discontinuity eastward. In any event, no significant rainfall is anticipated, even where rumbles of thunder disrupt outdoor activities. These precipitation processes are favored at night, and there should be a downward trend in intensity and areal coverage through midday. Convective debris may shave a few degrees off Saturday afternoon's temperatures, particularly south of the I-20 corridor where these mid and high clouds may linger longer. Highs will still easily reach the 90s regionwide. The disturbance aloft may still be above our Central Texas zones at peak heating, but there will likely be a disconnect between the unstable boundary layer and the forcing aloft. While we can't rule out some redevelopment, confidence isn't high enough to go above some silent 10-14 PoPs in our far southern zones. Our shortwave will arrive as the upper low to our east opens and ejects into the polar stream. This will leave a relative weakness in the mid-level height field between the intense anticyclone over the Desert Southwest and the semi-permanent Bermuda High. Guidance is coming into better agreement with the establishment of an inverted trough over the Lone Star State early next week. The main thrust of tropical moisture (perhaps with an attendant tropical cyclone) would be well east of our area, but rain chances will prevail across Central and East Texas during the middle of the week. A sharp PoP gradient may prevail within our CWA, but the eventual precipitation map will depend greatly on the evolution of the approaching tropical system. In any event, the lingering troughing may persist, which would enhance rain chances and reduce daytime temperatures through the following weekend. However, it would come with a price -- dew points remaining above 70F at peak heating. We'll continue to refrain from dousing the extended forecast with rain, which is quite contrary to climatology, but the coming week may be more eventful than its predecessor. 25 && .AVIATION... /Issued 1142 PM CDT Thu Aug 20 2020/ /06Z TAFs/ VFR at all TAF sites overnight through Friday night with a clear sky through Friday morning and increasing mid and high clouds Friday afternoon/night associated with an approaching shortwave. The arrival of the shortwave may generate a few showers and thunderstorms Friday night, especially west of the the I-35 corridor. Coverage of storms will be too limited to include in this TAF package. An east to southeast wind will prevail at all TAF sites through Friday night at speeds less than 10 knots. 79 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 94 73 94 74 95 / 0 10 10 10 5 Waco 97 73 95 73 97 / 0 20 20 10 5 Paris 90 68 91 70 92 / 0 5 5 5 5 Denton 94 71 94 72 95 / 0 20 10 10 5 McKinney 94 71 95 72 95 / 0 10 10 10 5 Dallas 94 73 95 75 95 / 0 10 10 10 5 Terrell 95 70 96 71 96 / 0 5 10 10 5 Corsicana 94 71 93 73 94 / 0 10 20 10 5 Temple 97 73 95 72 97 / 0 20 20 10 5 Mineral Wells 95 69 95 70 96 / 5 30 10 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 25/79