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KEY MESSAGES

Updated at 632 PM CDT Mon May 18 2026

- Extremely critical fire weather conditions and strong winds will continue through this evening.

- Storm chances arrive in the Rolling Plains early Tuesday morning along a cold front, with area-wide storm chances, some severe, continuing through the end of the week.

- Cooler temperatures will persist through most of the rest of the week.

SHORT TERM

(This afternoon through Tuesday) Issued at 220 PM CDT Mon May 18 2026

A bimodal risk of dangerous fire weather conditions and severe thunderstorms is expected, with the potential for severe storms confined to the eastern Rolling Plains. In the mid/upper-levels, an amplified, negatively-tilting shortwave trough was digging into the Four Corners region, with a 250 mb and 500 mb jet streak approaching 100 kt and 50 kt, respectively, rounding its base as the trough begins to eject northeastward into the central Great Plains. The most substantial large-scale forcing for ascent remains displaced to the north of the CWA as a result of the position of this compacted, shortwave trough, with only modest ascent expected over the Rolling Plains this afternoon. The 12Z RAOB from WFO AMA observed 55 kt and 50 kt of flow at 250 mb and 500 mb, respectively; as the left-exit region of the southern-stream jetlet remained positioned over the TX PH. High-level flow is expected to weaken by this evening as the negatively-tilted trough ejects over the NE Sandhills by 19/00Z, with mid-level flow eventually veering west-southwestward as the CWA becomes positioned beneath the bifurcated jetlets aloft. Deep- and cloud-layer shear will become modest tonight, with broadly cyclonic flow aloft expected to be maintained through the short-term period.

At the surface, a quasi-stationary front was located to the north of the CWA and across the OK PH, with the front bending northwestward where a lee cyclone near RTN was present. A weaker surface cyclone was located north of WWD, with the quasi-stationary front bending farther northeast into central KS. Sharp baroclinity exists with this front, with very cool temperatures on its north side along the I-70 corridor in northwestern KS where temperatures are currently in the middle 40s. There is also a 20-degree temperature gradient between LBL and HHF, or about 85 statute miles. The dryline extends southward from near DUX and is currently positioned along the edge of the Caprock Escarpment where a subtle bulge is present, with the 65 degree isodrosotherm delineated along the 100th meridian. Strong, southwesterly winds were present behind the dryline, with a 53 mph gust observed by the WTM site near Shallowater; and winds remain backed towards the south across the moist sector. Intense heating was also underway across the CWA, and temperatures have already breached 95 degrees for some locales in the Rolling Plains as of 1745Z where surface-based cu continues to bubble. Highs will breach 100 degrees east of the Caprock this afternoon, with near-record highs possible at CDS. For details involving the fire weather forecast today, please read the Fire Weather section below.

Isolated-to-widely-scattered thunderstorms are forecast to develop along the southern edge of the dryline bulge this afternoon across the eastern Rolling Plains, with the best potential for storms being in the southeastern zones. Storms that develop will be severe. The 12Z RAOB from WFO AMA sampled a well-defined EML, characterized by MLCAPE values near 2,200 J/kg and near 3,200 J/kg for most-unstable parcel trajectories. Mid-level cooling associated with the geopotential height falls have maintained very steep lapse rates atop moderate CINH, with L57 of 8.5 deg C/km, which matches current RAP estimates over the Rolling Plains. MLCINH was half of its value from yesterday, or around -131 J/kg, which will continue to erode across the moist sector throughout the afternoon as hot surface temperatures breach 100 degrees. Low-level convergence will be enhanced by the present of the subtle dryline bulge, and with minimal MLCINH by late-afternoon, rapid thunderstorm development is forecast to occur, with storms quickly becoming severe and posing a risk for damaging wind gusts up to 70 mph and very large hail up to baseball size. The potential for severe-caliber storms will be early on in the convective stage while cloud-layer shear magnitudes remain modest, at or around 30 kt, as the weakening 250 mb flow will curb hydrometeor venting within updrafts. Initial high-based LCLs within the hotter air will also enhance the magnitude of outflow(s), which may result in some localized merging/clustering of cells as diabatic stabilization of the boundary-layer begins. Therefore, the risk for severe storms will be short-lived, but the steep lapse rates and favorable wind profiles for mid-level mesocyclones yields confidence in an isolated, significant hail up to baseball size across the east and southeastern Rolling Plains. Storm chances along the dryline will end after dark, or by 19/03Z.

After dark, the quasi-stationary front currently draped across the OK PH will progress southward into the early morning hours Tuesday as the negatively-tilted trough dampens entirely. The movement of the cold front will be convectively-reinforced by a squall line/MCS across western OK and into the TX Big Country. Moist, isentropic ascent atop the sharp convergence along the cold front may result in the formation of a broken line of elevated storms along the front as it moves southward across the Rolling Plains during the predawn hours Tuesday. Moderate thermal instability will be maintained above the anafront, with the potential for large hail between 1-2" in diameter should updrafts be able to become organized. Otherwise, a mixed-mode of rain showers and weaker storms will be more common by dawn Tuesday. The front is forecast to clear south of the CWA after sunrise, with brisk, northerly winds expected post-FROPA. Winds will gradually veer throughout the morning and into the afternoon hours, with winds diminishing Tuesday afternoon. As previously mentioned, broadly cyclonic flow will persist aloft, and with the potential for convectively-augmented vorticity lobes to propagate over the Permian Basin and into the TX Big Country, elevated storms will be possible across the southeastern Rolling Plains into early Tuesday afternoon, but confidence in this scenario is low, and it appears that any storm potential will be south of the CWA. The surface and low-level airmass in the Rolling Plains will have been contaminated by the passage of the synoptic cold front and remnant outflow boundaries, but with upslope, low-level winds beneath southwesterly flow aloft, the potential cannot be ruled out for a localized severe storm across the southeastern zones. Otherwise, much cooler temperatures are forecast area-wide, with highs ranging from the middle 70s across the far southern TX PH to the middle 80s in the southern South and Rolling Plains.

Sincavage

LONG TERM

(Tuesday night through next Sunday) Issued at 220 PM CDT Mon May 18 2026

Broadly cyclonic flow is forecast to persist across the western U.S. through the latter half of the week. Cool temperatures are expected across the CWA Wednesday, with highs struggling to climb above the middle 70s as the post-frontal, upslope flow remains intact. The stalled front is forecast to bend northwestward into eastern NM late Wednesday, and with the CWA positioned beneath the right-entrance region to an amplified jet streak arcing into the Upper Midwest, there is an increasing potential for multiple rounds of storms from Wednesday afternoon into Thursday morning. Global and now-in-range mesoscale NWP guidance has been consistent in the potential for an overnight convective event as a vorticity lobe rotates towards the northeast out of northern Mexico, with the possibility for bands or clusters of storms to progress over W TX. Severe-caliber storms will be possible, with the potential for storms to produce heavy rain, but where exactly storms occur remains unclear. The primary severe hazards involved with storms Wednesday will be large hail, as the stalled front will be south and west of the CWA, thereby keeping parcel trajectories elevated above the cool, stable airmass. Storm chances remain forecast throughout the end of the week and into this weekend as broad troughing persists over the western U.S.

Sincavage

AVIATION

(00Z TAFS) Issued at 632 PM CDT Mon May 18 2026

VFR and strong south-southwesterly surface flow will continue through the rest of this evening, with winds then gradually weakening after sunset. A cold front will pass southward through the region tonight, and will bring a shift to strong north winds which will continue from before sunrise on Tuesday through the rest of the morning. Some convective development is expected along the front, with TS possible overnight especially at KCDS with lesser chances for thunder at KLBB and KPVW. A period of post- frontal MVFR CIGs is also possible at all sites on Tuesday morning, with highest confidence in MVFR CIGs at KCDS.

FIRE WEATHER

Issued at 220 PM CDT Mon May 18 2026

A high-end fire weather episode is underway today, with extremely critical fire weather conditions expected for a large portion of the CWA. Strong, southwesterly winds between 25-35 mph, with gusts up to 55 mph, will occur across the Caprock and into the far southeastern Texas Panhandle. The only change from the previous forecast(s) was a slight increase in wind gusts, with wind gusts up to 55 mph now expected across most of the Caprock. RH will fall to as low as 4 percent this afternoon amidst hot surface temperatures ranging from the lower-middle 90s on the Caprock to near or in excess of 100 degrees in the Rolling Plains. Very deep mixing of the airmass remains expected, which will facilitate the strongest wind gust potential beyond 3 PM CDT as temperatures peak. The dryline will move into the Rolling Plains by the mid-afternoon hours, with winds transitioning towards the south ahead of it. Isolated-to-scattered severe thunderstorms are forecast across the eastern Rolling Plains this afternoon and evening. Cloud-to-ground lightning strikes may occur in rain-free areas. Storms will be capable of producing damaging wind gusts up to 70 mph, with sudden and erratic changes in wind direction expected near storms. Otherwise, conditions will be favorable for dangerous growth and spread of wildfires through tonight. The Red Flag Warning remains in effect until 10 PM CDT for the Caprock and most of the Rolling Plains.

A strong cold front will move through the forecast area during the early morning hours Tuesday, and is currently forecast to cross into the far southern TX PH by 3 AM CDT. Trends in the frontal timing will continue to be monitored. A wind shift to the north will occur immediately post-frontal passage, with wind speeds between 15-25 mph and localized gusts between 30-35 mph expected as the cold front moves through the forecast area. Storms may also develop across the Rolling Plains along the cold front. The front is forecast to clear south of the CWA shortly after sunrise Tuesday, with northerly winds gradually diminishing while veering eastward into the afternoon.

LUB WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 10 PM CDT this evening for TXZ021>037- 039>043.

Wind Advisory until 8 PM CDT this evening for TXZ021>031-033>036.