DFW FORECAST DISCUSSION
000 FXUS64 KFWD 190050 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 650 PM CST Mon Jan 18 2021 ...New Short Term, Aviation... .SHORT TERM... /NEW/ /Through Tuesday Night/ Big changes are on the way as an unsettled weather pattern returns to North and Central Texas tonight and lingers through the end of the week. No significant departures from previous forecast with this update apart from adjustments to account for observations and latest trends in model guidance. Lower level moisture has been gradually increasing across the region today, discernible earlier on visible satellite as the deck of stratus that overspread the region early but has since gradually eroded and cleared. Low cloud cover will reassert itself and become more widespread this evening which will attribute to overnight temperatures remaining 10-15 degrees warmer than climatological normals for mid-January. Low temperatures will range from the lower 40s across northern and western North Texas to the mid to upper 50s across the southeast. A shortwave dropping through the Northern Plains has helped push a cold front across Oklahoma and parts of western North Texas this afternoon. This cold front, now draped just outside our northwest counties will advance slowly through the region tonight. The front is expected to reach the I-20 corridor between 9 PM and midnight with a notably slower forward progression as it approaches our far southeastern areas after daybreak Tuesday. Scattered showers are expected to begin developing late tonight along the southeastward advancing cold front. Isentropic ascent behind the cold front will lead to showers continuing Tuesday. The highest chances for rain will expand southward Tuesday morning through the afternoon, into areas generally near and south of I-20 where a pool of better moisture (PWATs in excess of 1") is likely to be concentrated. Mentions of isolated thunder have also been retained in this update with latest high resolution model guidance maintaining enough instability (300-600 J/kg) for a few rumbles of thunder south of I-20 and along and east of the I-35 corridor. Severe weather continues to look unlikely given limited instability. Behind the front, winds will shift to become northeasterly with sustained wind speeds increasing to 10-15 mph and gusts up to 20-25 mph possible in some locations. Weak CAA, breezy northerly winds, cloudy skies, and scattered showers will make for a dreary and cool Tuesday with high temperatures generally stalling in the upper 40s and 50s. High temperatures in the lower 60s will be likely in our far southeastern tier of counties, Milam to Anderson counties, where the slowed/delayed arrival of the front will allow these locations to spend an extended time in the warm sector. 12 && .LONG TERM... /Issued 227 PM CST Mon Jan 18 2021/ /Tuesday Night and Beyond/ Wet and unsettled weather will continue through the long term period with several rounds of rain expected over the next few days. An upper low near Baja California will remain nearly stationary on Wednesday, allowing southwesterly flow to bring ample Pacific moisture into the area. Periods of rain will be possible through Friday as the weakening trough slowly moves northeast. As it makes its final departure on Friday, a weak cold front will slide through the area, bringing a brief period of dry weather Friday night. As southerly flow is re-established on Saturday, rich Gulf moisture will advect into the area. Isentropic ascent within the plume of moisture should allow scattered showers to develop throughout the day. Meanwhile, a second upper trough will eject off of the West Coast. As it inches closer to the area, showers should gradually increase in coverage on Sunday. Showers and occasional thunderstorms will likely continue into early next week until another cold front brings drier air and cooler temperatures back to the region. Barnes && .AVIATION... /NEW/ /00 UTC TAF Cycle/ VFR cigs prevail but improvement will be short lived with MVFR conditions redeveloping tonight as a cold front approaches. SHRA are expected to begin developing well northeast of all TAF sites around 02-04Z Tuesday, as the southeastward advancing cold front crosses the Red River. Latest model guidance continues to show the potential for VCSH and MVFR cigs developing in DFW and Waco around 04-06Z. Isentropic ascent behind the cold front will lead to showers continuing through the day Tuesday. Occasional degradation to IFR cigs and SHRA possible at all Metroplex terminals between 07Z and 11Z and at Waco between 11Z and 15Z, as the cold front moves through the area. Higher moisture content across Central Texas will enhance the potential for lower cigs and impacts to vis. Southerly winds around 4-8 kts will shift to the northeast post- FROPA and increase to 10-14 kts with occasional gusts to 20 kts possible. 12 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 46 51 42 54 48 / 40 20 20 40 40 Waco 51 54 44 55 50 / 70 60 30 50 40 Paris 44 52 39 53 46 / 80 20 10 30 40 Denton 42 52 38 53 45 / 20 10 10 40 30 McKinney 44 51 39 53 47 / 60 20 10 40 40 Dallas 48 52 44 55 50 / 50 30 20 40 40 Terrell 47 52 41 54 48 / 70 40 20 40 50 Corsicana 52 55 45 56 50 / 70 70 20 40 50 Temple 50 55 44 55 49 / 50 70 30 50 40 Mineral Wells 42 51 39 53 45 / 10 10 20 40 20 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$