110 FXUS64 KFWD 101137 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 637 AM CDT Sun Mar 10 2019 .AVIATION... /12z TAFs/ A weak cold front has moved southward through the TAF sites over the past few hours, and winds are now prevailing out of the NNE around 8-10 kts. Southerly winds are in place just above the frontal inversion, which are contributing to ascent via isentropic upglide. This has resulted in showers and isolated storms across parts of West Texas this morning, and this activity will spread into parts of North Texas over the next 6-12 hours. I haven't indicated any precip at the TAF sites through today as strongest lift should remain just north of the immediate DFW area, but a VCSH mention may be necessary depending on trends later this morning. Meanwhile, an area of low-level moisture is contributing to fog and low cigs across parts of Central and southeastern Texas, some of which have spread into Waco in the past hour. Have introduced Tempo groups for IFR and MVFR cigs at Waco through midday to handle these conditions which will likely be intermittent. Otherwise, an increase in VFR cigs should occur through the afternoon and early evening hours as top-down saturation occurs and additional low-level moisture arrives. Later tonight, warm advection will increase over much of the area which will aid in the development of scattered showers heading into Monday morning. Have handled this activity with VCSH for now, but a TS mention may be necessary in future TAFs. In addition, low-level moisture will surge northward and become trapped beneath the frontal inversion. The resultant low-level saturation should become sufficient for MVFR/IFR cigs around the end of the TAF period, and have introduced worsening conditions in the extended DFW TAF. -Stalley && .SHORT TERM... /Issued 345 AM CDT Sun Mar 10 2019/ /Through Tonight/ A weak cold front is making its way through the forecast area this morning, and is located roughly along I-20 as of 330 AM. Behind this front, a light northeast breeze will aid in brining in slightly lower dewpoints as well as cooler air today. To the south, dewpoints remain mostly in the 40s or even low 50s. Later this morning, this front will decelerate and stall across parts of Central Texas, causing a 30F spread in both dewpoint and temperature across the CWA throughout the remainder of the day. At this point, the NAM has the best handle on the post-frontal airmass, and have trended heavily towards its solution through the short-term. Later this morning, warm advection will ramp up across the Concho Valley in advance of a deepening upper trough over the western US. Ascent atop the cold frontal inversion should result in a rapid expanse of low/mid clouds and the development of a swath of light rain. Initially, much of this activity may be in the form of virga due to dry air beneath the cloud layer, but the low- levels should saturate rather rapidly later this afternoon as top- down saturation occurs with aid from moisture return within southerly flow in the 850-700mb layer. Most of this activity should consist of rather light stratiform rain as it spreads into our western and northern zones throughout the day. However, a slight steepening of mid-level lapse rates later in the afternoon may allow for precipitation to become more showery in nature. Elevated instability appears a bit too low for a mention of thunder in the forecast, though slightly more robust convection supportive of a lightning strike may be possible across the far western and southwestern portion of the CWA around midday. PoPs will be highest over our northwest and decrease to the southeast, but just about any location within the forecast area has a shot at seeing some light rain throughout the course of this afternoon or evening. Otherwise, the vast expanse of cloud cover should keep temperatures on the cooler side of guidance, especially across North Texas where the post-frontal airmass and occasional rain will be located throughout the day. Locations that remain on the southern side of the stalling front may still manage to reach the upper 70s or low 80s, mostly across our far southeastern zones. The shallow frontal inversion will remain in place across the area into tonight with deep southerly flow beginning to strengthen just above. The increased warm advection should support an increase in sporadic rain showers, and also an increase in low stratus and some fog/mist heading into Monday morning. -Stalley && .LONG TERM... /Issued 345 AM CDT Sun Mar 10 2019/ /Monday through Next Weekend/ A frontal boundary will be draped across South-Central Texas and the northern Gulf at the start of the forecast period, placing North and Central Texas in a cool continental airmass as a deep upper low approaches from the west. The resulting overrunning pattern will bring cloudy conditions and increasing rain chances while temperatures remain in the 50s on Monday. The stronger isentropic lift may initially be located across the Hill Country associated with a lead shortwave to the southwest, with the higher POPs subsequently located across the southern half of the region Monday morning. This zone of relatively stronger lift will spread north as the disturbance moves northeast, shifting the higher POPs to the northern half of the forecast area Monday afternoon and evening. Precipitation will be primarily in the form of stratiform rain, but there should be enough elevated instability to generate isolated thunderstorms embedded within the broad precipitation shield. A lull in activity may occur Monday night as the disturbance continues off to the northeast, but showers should redevelop Tuesday morning associated with a similar upper level impulse. By this time, the boundary should begin to retreat northward as a warm front. The better chances of showers and storms will likely occur along and just north of the front, shifting from the southern counties northward across the rest of the area during the day. Warmer air will accompany the front as it moves northward, resulting in a continued damp but warmer day compared to Monday. High temperatures will range from the lower 70s across the south to near 60 along the Red River where the front will not reach until late afternoon or early evening. The upper low to the west will open up and acquire a negative tilt as it encroaches on West-Central Texas Tuesday evening. An area of strong forcing for ascent will allow for rapid convective development to the west of the forecast area during the late afternoon and evening hours. Showers and thunderstorms will likely evolve fairly quickly into a quasi-linear system as activity becomes organized along a Pacific front while approaching the western counties of North Texas late Tuesday evening. Instability still looks to be fairly marginal with most unstable CAPE values between 500 and 1000 J/KG. However, deep layer shear values exceeding 60kt will support the potential for a few severe storms with damaging wind gusts. This potential will accompany the line of storms as it pushes east across all of North and Central Texas during the overnight hours into early Wednesday morning. There will also be a chance of localized flash flooding where heavier rain occurs, particularly since we expect a couple more days of rain chances prior to the arrival of the main trough. Storm total precip values between now and Wednesday are generally in the 2 to 2.5 inch range, and areas which receive isolated higher totals will need to keep a close eye on local creeks and rivers, particularly since the heaver precipitation will occur at night. Showers and storms will exit to the east Wednesday morning, giving way to a dry and windy Wednesday afternoon across the board. The strongest winds will be across the northwest counties, which will be closest to the surface cyclone moving east and then northeast along with the upper level system. Winds generally north of I-20 and west of I-35 will be westerly in the 25 to 35 MPH range with higher gusts. A gradual decrease in velocities can be expected the farther southeast you go. We will then enter what at this time looks to be a dry period Thursday through next weekend, as northwest flow dominates the Central part of the CONUS. Seasonal temperatures and precipitation-free weather can be expected Thursday through next Sunday. Longer range models then show the potential for more unsettled weather just beyond this forecast period as we enter the second half of March. 30 && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 58 50 58 53 66 / 30 40 60 50 70 Waco 68 53 60 56 71 / 20 30 60 50 60 Paris 57 50 58 49 61 / 40 40 50 50 60 Denton 54 49 57 52 65 / 50 40 60 50 70 McKinney 56 49 58 52 64 / 40 40 60 50 70 Dallas 59 51 59 54 67 / 30 40 60 50 70 Terrell 65 52 59 52 67 / 20 40 60 40 60 Corsicana 69 54 58 54 69 / 10 30 60 50 50 Temple 69 54 62 57 71 / 20 40 50 50 50 Mineral Wells 55 49 57 51 67 / 40 40 60 50 70 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 26/30