726 FXUS64 KFWD 090532 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 1132 PM CST Thu Feb 8 2018 .AVIATION... The primary aviation weather concern overnight will be MVFR stratus. The stratus has already developed across the Hill Country and Central Texas and should reach DAL, GKY and DFW between 06 and 07Z and AFW/FTW about an hour later. The MVFR ceilings should remain in place through the morning hours Friday, but will lift above 4000 ft by midday and partially scatter, especially across the western TAF sites. Any lifting/scattering that does take place Friday afternoon will not last long with MVFR ceilings returning mid to late evening Friday when Gulf moisture surges northward. A southeast/south wind less at or below 10 knots overnight will become more southerly and increase between 11 and 15 knots Friday along with some higher gusts in the afternoon. 79 && .SHORT TERM... /Issued 259 PM CST Thu Feb 8 2018/ /Tonight/ Surface high pressure has shifted east of the forecast area, and weak return flow has begun across the northern half of the region this afternoon. The southern half will follow suit this evening as the ridge axis shuffles farther east towards the Mid Atlantic states. Low level flow will be on the increase tonight, and the resulting moisture return will lead to increasing low clouds across the eastern half of the region Friday morning. Higher dewpoints and southerly winds will keep temperatures above last night's readings, with lows ranging from the mid 30s along the Red River to the mid and upper 40s across the southern counties. 30 && .LONG TERM... /Issued 259 PM CST Thu Feb 8 2018/ /Friday through Wednesday/ A strong arctic cold front will be moving south across the Central Plains Friday in response to a mid level vort max moving east out of the Central Rockies. In advance of the cold front, falling pressure along the immediate lee of the NM/CO Front Range will allow for gusty south surface winds 15-20 mph and increasing moisture moving up from the Gulf of Mexico as 50s dew point temperatures return to the area. Some morning low clouds will encompass the southeast half of the region with a few afternoon showers across this same area. Most of the richest moisture will remain east of U.S. 281 from Jacksboro- Hamilton, so areas along and west of this area will see warm, breezy, and dry conditions that could result in an elevated fire danger Friday afternoon. Friday night will see the arrival of a southern stream vort max which will continue to enhance the low level warm advection ahead of the approaching arctic cold front. Column moisture will continue to deepen especially across areas east of I-35 overnight. The lift will help to moisten and eliminate the elevated inversion aloft with some skinny CAPE increasing across Central Texas. Chances of showers and possibly a few isolated, non- severe thunderstorms are expected across mainly the eastern half of the CWA. That said, precipitable water values do not appear to be very high, so rainfall amounts will average on the light side and below an inch in the east, with lesser amounts as you progress west toward the I-35 corridor. Meanwhile, the leading edge of the shallow arctic air will approach our northwest counties around daybreak Saturday morning. The higher resolution models such as the NAM, WRF, SPC HREF, Euro, and Canadian(GEM) appear to handle this very shallow airmass the best versus the GFS due to resolution. The GFS is still struggling with such airmasses that begin in the sub-boundary layer. Similar to the overnight forecast, we have blended a Euro, GEM, NAM with the arctic cold front. Regardless, the far northwest counties could see lows drop quickly into the 30s during the pre- dawn hours, with the remainder of the pre-frontal CWA remaining in the mid 40s to mid 50s. Some patches of light drizzle and even light fog can't be ruled out in the warmer and moist airmass ahead of the cold front late Friday night. This weekend becomes somewhat complicated, at least with precipitation timing and potential, while there's no doubt about the chilly airmass coming down. Ahead of the cold front, many areas will see highs occur in the mid-late morning, possibly early afternoon before temperatures rapidly tank the remainder of the day. Patchy drizzle and possibly some light fog will continue during the morning hours in advance of the arctic cold front. Meanwhile, the aforementioned southern stream vort max will be tracking east over Central and Southeast Texas through the day with lingering chances of showers and a few isolated thunderstorms, especially south of I-20/30 through much of the day. The cold front is expected to have easily cleared our area by Saturday night, as we have a brief lull in activity Saturday evening. However, a much stronger vort max will be trailing and moving southeast across the Four Corners region and Central/Southern High Plains during the overnight hours. Increasing pressure advection (ie...lift) will be punching into the Hill Country and Permian Basin areas on the 300K-310K surfaces with some weak instability aloft. Though 25-30 knot flow appears parallel with little in the way of isentropic upglide, the pressure advection itself will likely result in some overrunning, light precipitation across mostly Central Texas. That said, weaker overrunning is possible further north and west. Low chances of a light freezing drizzle or very light rain may occur across areas northwest of a Cooper, to Coriscana, to Gatesville and Lampasas line. The positive-tilted strong vort max looks to exist east across KS/OK during the day Sunday, so bulk of the better forcing will remain north of the better moisture and within the deeper and drier arctic air to our north. As such, we "may" see a mix of light freezing drizzle, freezing rain, or drizzle along a corridor from Sulphur Springs to Hillsboro, to Lampasas/Killeen briefly Sunday morning before temperatures warm to above freezing. Further south a cold rain is expected. Low chances for a a light cold rain will linger over Central Texas Sunday afternoon with highs struggling to reach the lower-mid 40s. Confidence is high on the shallow arctic air and very cold temperatures, but low on the evolution of moisture, lift, and any overrunning for light precipitation before the deeper and dry arctic air arrives on Sunday. Any light precipitation should end across our eastern counties sometime Sunday evening and while temperatures remain above freezing. By Monday morning, all the forcing from this system will have moved off to the northeast with a very chilly start to the day. Highs Monday will struggle to get into the lower to mid 50s. The shallow arctic cold air looks to shift to the east by Tuesday and moving into the mid week period, as an organizing mid level trough across the Northern Rockies and Great Basin helps induce lee cyclogenesis and the return of southerly flow across the Plains and our area. Both temperatures and modified Gulf moisture return with highs warming back into the 60s with overnight lows generally in the 40s and 50s. The resultant low level warm advection will likely result in some low rain chances across mainly the eastern half of the region once again, while the western areas are left out once again. 05/ && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 40 69 50 50 29 / 0 0 20 20 20 Waco 43 70 54 55 33 / 0 0 20 20 30 Paris 38 61 50 50 29 / 0 0 40 40 30 Denton 37 69 44 44 26 / 0 0 10 20 10 McKinney 38 66 50 50 28 / 0 0 20 20 20 Dallas 41 70 52 52 30 / 0 0 20 20 20 Terrell 39 66 52 53 29 / 0 0 30 30 20 Corsicana 44 67 54 55 32 / 0 0 30 30 30 Temple 44 69 53 55 33 / 0 0 20 20 30 Mineral Wells 35 74 41 41 24 / 0 0 5 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 79/92