Scientific Forecaster Discussion
000 FXUS64 KFWD 140005 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 605 PM CST Wed Nov 13 2019 .AVIATION... /00Z TAFs/ An upper level low continues to spin across the Sierra Madre in Mexico, and is gradually moving to the east. This upper level low has allowed for a continuous stream of mid and upper level moisture to move northward into North and Central Texas. Some light rain and drizzle has been reported across portions of Central Texas, but given the overall dry low levels, VFR continues for much of the region. As we continue through the evening and into tonight, a gradual top-down moistening is expected mainly across Central Texas, where total column moisture will be enough for light precipitation. A cold front will also be moving through the region, turning our current southerly winds into northerly winds around 12Z Thursday at DFW and 14Z at Waco. Along with the northerly winds, a brief period of MVFR is expected in the wake of the cold front, with light rain once again possible. The cold front will help usher in much drier air into the region by Thursday afternoon, helping to clear the skies yet keeping the northerly winds in place around 10 knots. Hernandez && .SHORT TERM... /Issued 1226 PM CST Wed Nov 13 2019/ /This Afternoon through Thursday/ High clouds continue to stream in across Central and North Texas ahead of an upper trough over northern Mexico. This disturbance is expected to move into South Texas later tonight into early Thursday morning. As it does, low and mid level warm advection will intensify, although moisture will be a little sluggish to return. Skies are currently overcast around 12,000 ft in Central Texas, but we should see a gradual saturation down to around 4,000 ft later this evening. Closer to the surface, the air is quite dry, as indicated by dewpoints in the low/mid 20s well down into South Texas. Given the lack of a more robust low level moisture return, expected rainfall amounts with this system should be fairly light. Areas of light rain or sprinkles may develop later tonight across our southeastern counties as stronger forcing for ascent arrives. Meanwhile, a stronger shortwave trough will be swinging through the Central U.S. through tomorrow morning. This will send another cold front southward and into the region during the early morning hours on Thursday. While there will be some convergence along the front, moisture is still expected to be too limited for a better coverage of rain. We'll hang on to some PoPs across our southeast counties through the afternoon, but much drier air will filter in behind the front and skies should become mostly clear by evening. Low temperatures tonight should drop into the low/mid 30s for most locations, while highs on Thursday should be in the mid 40s to lower 50s. The coldest air on Thursday should be in our southeast where clouds and rain chances will linger into the afternoon. Dunn && .LONG TERM... /Issued 335 PM CST Wed Nov 13 2019/ /Thursday Night Through the Middle of Next Week/ A progressive pattern will prevail the remainder of this week and throughout the coming week. This will mean periodic cold fronts, delaying the return of above normal temperatures. It will also prevent effective moisture return, maintaining a mostly rain-free forecast. In the wake of our next cold front, drier air will filter into the region Thursday night with clearing skies and diminishing winds. Much of the region will awaken to freezing temperatures Friday morning, sauf the heat island of the Metroplex and a handful of locations that are both east of I-35 and south of I-20. However, the dry air and abundant sunshine on Friday will effectively erode the shallow layer of cold air. This will help the warming trend in our high temperatures to continue unabated, with most locations reaching the upper 50s Friday afternoon. Southerly winds will return on Saturday. While this will only add a couple of degrees to our temperatures, its main impact will be to boost the low-level moisture to levels not seen since before our recent arctic blast. This will set the stage for our only decent rain chance in the 7-day forecast on Sunday when a trough emerges from the Rockies and swings through the Lone Star State. Since this feature is still in the data void of the eastern Pacific, there are significant disparities with its evolution and timing. In any event, its forcing alone should realize some rain, and the moistened sub-cloud layer should help these drops reach the ground. This would be a quick shot as the trough races past during the Sunday into Sunday night time frame. The trough's passage will usher in another cold front, but this one would be of Pacific origin. This means minimal cold advection and downsloping winds that will result in a sunnier and warmer day on Monday. A period of longwave troughing will prevail thereafter, pushing afternoon temperatures into the 70s by Tuesday and Wednesday. 25 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 35 53 34 58 36 / 10 5 0 0 0 Waco 36 49 33 59 34 / 30 30 0 0 0 Paris 33 51 31 56 31 / 10 5 0 0 0 Denton 30 53 31 57 34 / 5 0 0 0 0 McKinney 33 52 31 57 34 / 10 5 0 0 0 Dallas 37 54 34 58 36 / 10 5 0 0 0 Terrell 36 51 32 58 33 / 20 20 0 0 0 Corsicana 37 48 34 57 34 / 40 30 0 0 0 Temple 36 48 32 59 33 / 50 30 0 0 0 Mineral Wells 33 54 30 57 32 / 5 0 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... None.