935 FXUS64 KLUB 201627 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1127 AM CDT Mon Sep 20 2021 .UPDATE... Today's cold front is a bit ahead of schedule having already moved into the northern row of the forecast area. Will make some adjustments to the wind forecast to account for this. It is a bit unclear how quickly cooler air will move in behind the front. May end up having to lower high temp forecast for the northern part of the forecast area, but will hold off for now pending further data. && .PREV DISCUSSION... /issued 619 AM CDT Mon Sep 20 2021/ AVIATION... VFR next 24 hours. A cold front will move into the area around mid-afternoon bringing winds around to the north at KCDS first followed by KPVW and KLBB a few hours later. Expect hot and bumpy thermal turbulence today with most normally aspirated aircraft unable to climb high enough to find smooth air after 18Z. Check density altitude. There is a ~10pct chance of thunderstorm development east of a LBB to CDS line late this afternoon. Underflight of showers/virga not recommended due to threat of strong downburst winds. PREV DISCUSSION... /issued 306 AM CDT Mon Sep 20 2021/ SHORT TERM... A shortwave trough will traverse the central and northern plains today. The morphology of the trough tends to suggest a double- shot of energy. That is, an initial front followed by a secondary surge of cooler/drier air hours later. The trough axis is progged to deepen somewhat over the next 24 hours which will help reinforce the cooler airmass driving it southward. Subsident compression of the frontal boundary combined with westerly downslope winds will allow temperatures to get quite toasty this afternoon. The dryline should race east after sunrise making it to our eastern counties by mid-day. By mid-afternoon, a cold front should be arriving in our northeast which will set up a triple- point in the Rolling Plains late this afternoon. There will be scant little moisture to work with though forecast soundings do suggest at least some potential for virga and perhaps a dry thunderstorm closer to the triple point itself. All in all, the prospects for measurable rain at the surface are pretty meager...certainly below mentionable levels. However, any virga that develops will have the capability of producing strong downburst winds given the inverted V soundings anticipated. Wind gusts to 55 mph, and possibly higher, seem legit if we can get the precipitation processes going aloft. Honest thunderstorm development is certainly possible to our southeast late this afternoon and evening. The front will bring cooler lows (55- 65) tonight but it will take that second frontal surge on Tuesday to make it feel a lot more like fall. LONG TERM... By Tuesday morning the aforementioned cold front will be well south of the forecast area. The surface pressure gradient will remain tight across the region Tuesday morning and early afternoon keeping northerly winds breezy and bringing in the secondary surge of cooler/drier area. Temperatures will be much cooler on Tuesday with high temperatures in the 70's on the Caprock and lowers 80's off of the Caprock. By Tuesday night surface high pressure will settle across the southeastern Texas Panhandle bringing light winds and clear skies to the region. This will allow for excellent cooling conditions across the higher terrain of the forecast area and a few upper 30's would be possible in the typically cool spots with 40's and lower 50's possible elsewhere. By Wednesday, upper level ridging will begin to expand across the Desert Southwest although height rises will not be all that impressive. This means that temperatures will only slowly warm each day through the end of the week. The upper level pattern becomes more uncertain this weekend as models struggle with a cutoff low over southern California due to differences in the strength and location of a shortwave moving across the Pacific Northwest. However, these differences won't impact the forecast area too much until early next so dry conditions and gradually warming temperatures can be expected through the weekend. /WCI && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 07