@ FXUS64 KLUB 201105 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 605 AM CDT Wed May 20 2026 ...New AVIATION... .KEY MESSAGES... Updated at 537 AM CDT Wed May 20 2026 - Overcast and some fog returns Wednesday, with chances for showers and thunderstorms arriving late Wednesday morning. - Brief, heavy rainfall will be common with storms Wednesday, with hail up to quarter size possible. - Daily chances for showers and thunderstorms are forecast to continue through this weekend. && .SHORT TERM... (Tonight through Wednesday night) Issued at 1046 PM CDT Tue May 19 2026 01Z upper air analysis depicts a large-scale, positively-tilted trough over the Intermountain West, with an ill-defined vorticity lobe evident on recent water-vapor imagery that was ejecting northeastward over Baja Sur and into northern Mexico. A disheveled and expansive baroclinic leaf is present, as it has been stretched out while rounding the base of the trough is it begins to become absorbed into the right-entrance region to a 250 mb jet streak that was objectively analyzed at 95 kt per the 20/00Z UA charts. Broadly cyclonic flow will be maintained over the CWA throughout the course of the short-term period, with the right-entrance region to the mid- and high-level jet streaks translating eastward and over W TX by Wednesday afternoon. Meanwhile, a subtle shortwave trough embedded within the larger-scale flow has resulted in thunderstorms far to the south of the CWA, with thick anvil debris advecting poleward over the Rolling Plains and eclipsing the Caprock. Low-level clouds have since mixed out on the Caprock, but with northeasterly flow persisting at 850 mb, low stratus remains dammed over the Rolling Plains per METAR data at CDS and VUF. Occasional breaks in the anvil debris field have also revealed the extent of the stratus deck. Fog is forecast to develop across portions of the Rolling Plains, and perhaps the Caprock, Wednesday morning as the lower boundary-layer nears its saturation point during the predawn hours. At the surface, the cold front that crossed through the CWA earlier this morning has stalled across the southern portion of the Edwards Plateau, and bends northwestward into the TX Big Bend and beyond into the southern Rocky Mountains. A lee cyclone was analyzed near the Sierra del Carmen, with WTM data observing the northern periphery of the low; and the quasi-stationary/slow-moving cold front then branches eastward into the Llano Uplift before bending northward towards central N TX. This front is expected to remain anchored across that corridor for the next 24 hours, which will maintain the upslope/easterly flow across the CWA tonight into Wednesday. However, the western periphery of the stalled front will serve as an impetus for the initiation of clusters of showers and thunderstorms by late Wednesday morning for portions of the CWA. The vorticity lobe analyzed over Baja Sur will emerge over the TX Big Bend and eastern NM near sunrise Wednesday, with the anomaly becoming stretched and elongated as it ejects over the CWA. This will occur in conjuction with the right-entrance region of the 250 mb jet streak translating over W TX, facilitating a net increase in high-level divergence and subtle geopotential height falls atop the stable, post-frontal airmass. Elevated, fast-moving clusters of showers and storms are forecast to develop by late Wednesday morning and into the early afternoon hours as the PV anomaly ejects over the CWA. The subtle geopotential height falls and backing of deep-layer flow aloft towards the southwest will advect the EML observed by the 20/00Z RAOBs from MAF and MMCU over the CWA, with MUCAPE values increasing to 1,000-1,500 J/kg atop the stable and near-saturated boundary-layer. Modest effective shear magnitudes near 30 kt and somewhat elongated hodographs in the mid/upper-levels will yield the potential for weak, mid-level mesocyclones to develop within the elevated storms; and with parcel trajectories rooted above the stable airmass, hail up to quarter size will be the predominant severe-related hazard with storms Wednesday. Brief, heavy rainfall will be common with storms otherwise, although the quick progression of storms will curtail the potential for flash flooding. The dense overcast will restrict diabatic heating, with highs forecast to struggle to breach 70 degrees across most of the CWA, especially as the upslope flow is maintained through most of the day. Storm chances will wane by the evening, with cool and damp conditions expected overnight into Thursday along with the potential for fog. Sincavage && .LONG TERM... (Thursday morning through next Tuesday) Issued at 1046 PM CDT Tue May 19 2026 Large-scale troughing will persist across the western U.S. Thursday, with a compact, shortwave trough forecast to dig into the Mosquito and Sawatch Ranges. Broadly cyclonic flow will be maintained over the CWA, albeit a dearth in magnitude as it becomes subgeostrophic between the base of the shortwave trough to the north-northwest of the CWA and the quasi-zonal, subtropical jet streak nosing into the Sierra Madre Occidental. Another small-scale, shortwave trough is forecast to eject into western TX Thursday, with the boundary-layer becoming weakly capped as low-level stratus erodes. Temperatures are forecast to be 5-7 degrees warmer than Wednesday, but with minimal MLCINH forecast as warmer theta-e air advects into the CWA as a weak, low-level jet near 25 kt backs towards the southeast by late Thursday afternoon, clusters of storms are forecast to develop and move towards the east-northeast across the CWA Thursday afternoon and evening. Isolated instances of marginally-severe hail will be possible given a slight uptick in effective shear magnitudes to around 35 kt amidst the maintained EML. NBM PoPs have been adjusted accordingly to reflect the best timing. Isolated storm chances are forecast to continue for portions of the Rolling Plains by Friday, with area-wide chances into the weekend. The large-scale troughing is forecast to attenuate and split into lower-amplitude shortwave troughs, with the southern-stream shortwave trough arriving by this weekend. Warmer temperatures will follow, with the best storm chances appearing to be east of the I-27 corridor Friday and into the weekend. Some storms may be strong-to-severe, but mesoscale details remain nebulous with this prognostication. Additional storm chances may arrive early next week, but predictability is limited. Sincavage && .AVIATION... (12Z TAFS) Issued at 537 AM CDT Wed May 20 2026 MVFR CIGs are expected to lower to IFR at PVW and LBB shortly after 12Z along with a reduction in VIS to low VFR/MVFR. Convection will be possible at LBB and PVW between 18Z-00Z. Some storms could be strong to severe and produce wind gust up to 50 knots and hail up to one inch in diameter. While it is possible for these storms to reach CDS by 00Z, confidence is too low for a mention in the TAF at this time. IFR CIGs will move back over the terminals after 06Z tonight. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...09 LONG TERM....09 AVIATION...51