656 FXUS64 KLUB 020959 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 359 AM CST Wed Jan 2 2019 .DISCUSSION... The forecast remains focused on possible wintry impacts later today (primarily tonight) into Thursday and the Winter Storm Watch remains in place for much of the region from this evening through Thursday afternoon. Overall the latest trends favor less snow for our area, with the best chances still residing over the more eastern locations off the Caprock. However, with the instigating upper level low still spinning across the Desert Southwest and not moving much, there is a lot that could change yet before it emerges over the southern High Plains in the next 24 to 48 hours. Given this, we are not planning on making any changes to the ongoing headlines (Winter Storm Watch) even though the current NWP would suggest more of an advisory level event for most/all of our CWA. Instead, since any real impacts likely won't be felt until late this evening/tonight, we will not commit to any one outcome just yet. That said, we will be scaling back expectations in the WSW product. Jumping into the details, we are seeing a nice warm conveyor belt forming across the center part of the state early this morning. The bulk of the lift/precipitation with this will remain well to our east, though we can't completely rule out a light wintry mix (or just FZDZ) brushing our far southeast CWA around Stonewall County. Progged sounding around Aspermont would support freezing rain and/or sleet with a weak warm nose around 5000 ft AGL. In fact, the NAM even suggests a little weak elevated instability developing late this afternoon into this evening, so isolated convective wintry showers may be possible there around and after 00Z. Before then, precipitation, if any, should be very light and we don't anticipate any impacts. Otherwise, we'll have to wait for the lift associated with the upper low to bring more widespread precipitation chances to northwest Texas. NWP are in decent agreement that the upper low will begin a more eastward trek late this morning, moving across southern NM this afternoon and evening, then traversing the South Plains and/or northern Permian Basin late tonight through Thursday morning. Overall, NWP agree on the timing, with about 50 to 100 miles of difference (north to south) on where the center of the low will be by 18Z Thursday. Obviously, these track difference can have big implications on who receives the most snow. Probably more importantly though is the fact that currently all of the guidance consulted have the upper low maintaining a positive tilt until around 12Z Thursday before becoming neutral. This effectively blocks the better low/mid-level moisture from wrapping back into the upper low, delaying a good TROWAL development until later on Thursday as the system is starting to pull away from the area. This is the main limiting factor regarding snow amounts late tonight into Thursday morning, and would effectively limit snowfall for much of the FA, except perhaps across our far eastern counties where the maturing TROWAL could play a bigger factor. Further west, we will still have the deformation with the upper low try to squeeze out some snow, though it may also be fighting some dry mid-level air. Regarding p-type, aside from the Rolling Plains, which could see a little wintry mix (sleet and/or freezing rain this afternoon into this evening), snow should be the primary mode through the event. Taking into account these latest trends, we now have a dusting to half inch of total snow forecast for spots on the Caprock between this evening and Thursday afternoon. Snow totals do increase to 1-3 inches over the central and eastern Rolling Plains and far southeast Texas Panhandle, though this could even be a little too high if the latest guidance is correct. It will all depend on the exact track of the low and when the deeper moisture (TROWAL development) can be tapped. Since cutoff upper lows are notoriously difficult to forecast, we wouldn't be surprised if things still change significantly from what is currently forecast. Stay tuned! Beyond this storm system, upper ridging will provide a nice warm up late week into the weekend. In fact, if the precipitation does come up on the light side the next couple of days, forecast highs could be 5 to 10 degrees too cool. The next storm system, likely an open trough, is then progged to pass on Monday. Current projections would favor more of a wind event, though it may carry just enough Pacific moisture in advance of it for a few showers in the region Sunday night into early Monday. Only minor adjustments were made to the blended guidance beyond this initial winter storm, primarily to boost forecast wind speeds on Monday. && .LUB WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from this evening through Thursday afternoon for TXZ022>026-028>032-034>038-040>044. && $$ 23