Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 02/01/19

Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
907 PM CST Thu Jan 31 2019 .UPDATE... Going forecast remains in pretty good shape, but made some adjustments to re-trend temperatures and dewpoints based on recent observations. Temperatures are in the upper 40s to mid 50s and won`t move all that much more overnight under thick cloud cover and persistent southerly flow, so nudged overnight lows up a degree or two. Drizzle and light fog has started to develop across parts of Central Texas, and anticipate a northward expansion of reduced visibilities through the rest of the evening more-or-less along and west of the I-35/35W corridor. Upstream visibilities haven`t gotten out of hand just yet, running generally in the 1 to 4 mile range, but Hamilton has just fallen below a mile. We`ll continue to keep an eye on observation trends here this evening, but don`t have plans to hoist a Dense Fog Advisory at this juncture, although one may be needed a bit later tonight. Updated products have been transmitted. Carlaw && .AVIATION... /Issued 613 PM CST Thu Jan 31 2019/ /00z TAFs/ MVFR cigs at FL012-022 prevail at all TAF sites early this evening, and a gradual deterioration in flying conditions is anticipated through the evening hours as the low-levels cool and additional moisture surges out of the Hill Country. Both statistical and perfect-progged hi-res guidance indicate the development of IFR cigs--initially at KACT after about 02/03z, followed a few hours later in the Metroplex. Cloud bases are expected to build down further into the LIFR category overnight, and confidence in this potential has increased enough to warrant a prevailing mention at all TAF sites. Recent ACARS soundings from KDAL and the currently-ascending KFWD balloon indicate the top of the stratus deck is right around 840 mb/5000 feet. This is likely too shallow to support much in the way of shower activity tonight and Friday morning, with drizzle the more likely scenario as dewpoint depressions fall to under 2 C and veering low-level flow supports modest warm advection within the cloud layer. In addition, forecast soundings seem supportive of fog (even with modest 25 kt winds present just off the surface). Hi-resolution guidance indicates the potential for LIFR and even VLIFR vsbys in DZ/BR overnight and into the morning hours on Friday and right on through the DFW morning push. Conditions will be slow to improve on Friday with no real impetus to scour low- level moisture out. As a result, the latest TAFs are fairly pessimistic, indicating IFR through much of the day at Waco, and low-MVFR conditions at the Metroplex sites during the early- afternoon. IFR cigs will probably need to be added into the DFW extended TAF in the 06z issuance. Surface winds will generally be out of the southeast at under 10-12 kts through the forecast period. Carlaw && .SHORT TERM... /Issued 338 PM CST Thu Jan 31 2019/ /Tonight and Friday/ The injection of Gulf moisture across North and Central Texas continues this afternoon resulting in widespread low cloud cover. Veered 925-850 mb winds are helping to scour out the low clouds immediately west of US-281 where mostly sunny to partly cloudy conditions will prevail for the remainder of the afternoon, but backing flow will ensure additional low clouds slosh back to the west this evening and overnight. With the strongest warm advection/isentropic upglide displaced generally north of the Red River this evening and the low-levels only saturated up to about 850 mb, the potential for measurable rainfall appears low tonight, and carrying 20-30% PoPs seems reasonable for locales roughly along and east of I-35. Instead, a combination of drizzle and fog appears more likely. Based on this afternoon`s model guidance, expanded the mention of fog to essentially all of North and Central Texas tonight, with drizzle wording confined within the deepest part of the moisture plume across the eastern half of the CWA. We`ll have to keep an eye on visibilities this evening and overnight, with indications that dense fog will be possible as a notable hydrolapse develops in the 1000-900 mb layer and an additional wave of moisture surges out of the Hill Country. We`ll let the evening shift assess observation and hi-resolution guidance trends for any potential Dense Fog Advisory issuance. Fog and drizzle will linger into the morning hours on Friday, but conditions should slowly improve by noon or so. With no impetus to scour out the low-level moisture, it looks like locales east of US-281 will remain socked in with low clouds through the afternoon hours, which obviously has implications for the high temperature forecast. Think that the GFS-based statistical guidance is a bit too warm where clouds are expected to remain in place, and nudged highs towards the cooler NAM/MET guidance. Better insolation may occur west of US-281 where diurnal mixing may be able to chew away at the thinner moisture plume, and nudged highs into the upper 60s there as a result. Carlaw && .LONG TERM... /Issued 338 PM CST Thu Jan 31 2019/ /Friday Night and Beyond/ By Friday night, the shortwave will enter North and Central Texas, with the best forcing spreading into Central Texas after midnight. The latest CAMs continue to lack in developing showers and thunderstorms, but given steep midlevel lapse rates of 6.5-7.5 C/km and the possibility of saturated parcels overcoming the weak cap around 800 mb, some elevated activity remains possible during the overnight hours. Any elevated storms would be able to produce small to marginally severe hail during this time. As the shortwave exits from west to east on Saturday, rain chances will end as well. Latest guidance keeps most of the weekend rain- free, but abundant cloud cover will remain across the region. The first weekend of February will be warm, with highs on Sunday in the 70s across the region. Mild nights with lows in the 50s to near 60 degrees are expected. Despite temperatures 20-25 degrees above normal, our record maximum and highest minimum temperatures should remain safe. Warm weather will continue on Monday and Tuesday, with some low rain chances possible beginning Monday afternoon as a weak disturbance slides across the region. At this time, model soundings support scattered showers as a cap around 800 mb remains in place. Some isolated thunderstorms will be possible across Central Texas, where the cap is weaker. Meanwhile, across the western US, an upper level trough will deepen and begin to track eastward towards the Plains. This system will bear watching over the next several days, as a strong cold front accompanied by precipitation chances will move across North and Central Texas Wednesday night into Thursday. While ensembles and long range guidance have hinted at the possibility of wintry precipitation, it is far too early to include in the forecast. Villanueva-Garcia && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 51 62 53 67 56 / 20 10 40 20 5 Waco 54 63 54 68 57 / 20 20 40 30 10 Paris 46 57 49 62 55 / 20 20 20 30 10 Denton 50 62 51 67 55 / 20 10 30 20 5 McKinney 50 60 51 64 56 / 20 20 30 30 5 Dallas 52 62 53 67 56 / 20 20 40 30 5 Terrell 52 62 51 66 56 / 20 20 40 30 10 Corsicana 52 64 52 65 57 / 20 20 40 30 10 Temple 53 64 54 67 57 / 20 20 40 30 10 Mineral Wells 50 65 51 67 55 / 10 5 30 20 0 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 90/25