Area Forecast Discussion
Issued by NWS
Issued by NWS
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259 FXUS64 KLUB 231839 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 139 PM CDT Sun Jun 23 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Monday) Issued at 139 PM CDT Sun Jun 23 2024 A non-zero chance of isolated convection will exist for the extreme southwestern Texas Panhandle late this afternoon into the evening. Mid-level moisture was still prevalent rotating around the ridge although most activity will be confined to eastern New Mexico and into the central and northern Texas Panhandle. Upper level ridging will continue to linger over central Texas and slowly drift westward through Monday centering over El Paso by Monday afternoon. This will act to shunt the mid-level moisture farther to the north rotating around the ridge and eliminate any chances of isolated convection for Monday afternoon. A slight increase in heights/thickness values on Monday will result in a small bump in temperatures upwards as well. && .LONG TERM... (Monday night through next Saturday) Issued at 139 PM CDT Sun Jun 23 2024 Mid/upper-level ridging will continue to amplify into Tuesday as a barotropic low located west of Baja California rotates eastward and as a more-amplified, baroclinic, mid/upper-level trough digs into the Pacific Northwest. The net response of these features emerging towards western North America will result in an anticyclonically- curving, 250 mb jet streak over the central Rocky Mountains with its right exit-region nosing into the TX PH by late Tuesday. At the surface, diffuse troughing extending to the south of a lee cyclone in eastern Colorado/western Kansas will maintain slightly backed flow during the afternoon hours as intense insolation causes high temperatures to soar into the upper 90s across the Caprock and breach 100 degrees in the Rolling Plains. Heat indices may approach 105 degrees across portions of the Rolling Plains on Tuesday. (Heat Advisory criteria are temperatures or heat indices between 105-109 degrees for the Rolling Plains.) Weak, mid-level, shortwave perturbations translating about the apex of the ridge; in addition to MLCINH becoming completely eroded beneath a tall, skinny EML, will support the potential for thunderstorms across the extreme southwestern TX PH and farther southwestward into the South Plains. Low PoPs have been maintained for Tuesday evening across these locales as it remains unclear how far east thunderstorm initiation will occur in eastern New Mexico. Steering flow magnitudes between 10-15 kt will also result in slow-moving storms, with the mean convective movement governed by propagation effects from merging cold pools before chances for storms wane early Wednesday morning. Wednesday is forecast to be the hottest day of the work week as geopotential heights rise to near 596 dam in the mid-levels, with 850 mb temperatures nearing 30 deg C. Surface temperatures are forecast to approach 102-104 degrees across the eastern portions of the Rolling Plains while near 99-100 degrees towards the edge of the Caprock Escarpment. Heat index values between 105-108 degrees are forecast for the eastern Rolling Plains (i.e., Childress County southward into Stonewall County), which is within Heat Advisory criteria. The blended temperatures have been maintained and are slightly below the statistical guidance envelope, and this is due to the potential effects of evapotranspiration from lush vegetation. However, area-averaged forecast soundings do indicate a well-mixed boundary-layer developing while dewpoints remain within the middle 60s by peak heating. If hotter temperatures are realized, then heat indices could approach 110 degrees for portions of the eastern Rolling Plains on Wednesday afternoon. Farther west, temperatures are forecast to peak in the upper 90s across the Caprock Escarpment amidst the dampened, southeasterly breeze; and renewed chances of late-afternoon and evening thunderstorms remain intact across the northwestern South Plains into the extreme southern TX PH as the core of the subtropical ridge begins to rotate eastward. Very warm temperatures are expected on Tuesday and Wednesday morning, too, especially across the Rolling Plains where lows near 80 degrees are forecast, further contributing to the heat stress. Towards the end of the week and into next weekend, the amplitude of the subtropical ridge will dampen due to the progressive wave pattern along the 49th parallel, with the center of the 250 mb anticyclone rotating into eastern Texas or perhaps farther east. Global NWP guidance remains in agreement with the longitudinal extension of the subtropical ridge as it phases with an another amplified ridge over the North Atlantic. PoPs have been maintained for this forecast package; however, uncertainty exists with where the fetch of monsoonal moisture will be positioned by next weekend and one can expect adjustments to these PoPs until then. Otherwise, hot and breezy conditions are forecast through the end of the period as surface troughing and return flow persist across the entire CWA with temperatures remaining in the middle-upper 90s by next weekend. Sincavage && .AVIATION... (18Z TAFS) Issued at 1208 PM CDT Sun Jun 23 2024 VFR will prevail through the TAF period. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...01 LONG TERM....09 AVIATION...01