333 FXUS64 KAMA 192031 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 331 PM CDT Sun May 19 2019 .SHORT TERM... A H5 low center will cross very close to SRn NV through 12Z Monday. This location is favored for significant Panhandles severe events. Models agree on impressive h85-h5 theta-e advection and good upper diffluence in the jet exit region late tonight into tomorrow in advance of the first disturbance rounding the base of the low center. Isentropic upglide is also impressive, with 40-50kt upglide in the 305-315K layer per the NAM12. This all points to an early beginning of TSTMs before sunrise Monday morning. Although storms will be elevated above the shallow cool stable layer, impressive wind shear in the 1-7 km convective layer and elevated CAPE pushing 3000 j/kg suggests elevated supercells (or at least storms w/ supercell characteristics) with very large hail are possible late tonight and Monday morning. Elevated nature of the initial storms should preclude a tornado threat initially. Going pretty high on POPs for late tonight into Monday morning based everything mentioned above. The first area of storms will shift east through the morning, although individual storms will be moving more NE (35-45 mph, closer to 50 mph later). Wind shear will be impressive all day and into the evening with 0-6km bulk shear remaining very high (60-80 kts). 0-1 helicity is forecast to be in excess of 200 m^2/s^2 for much of the area as well. LCLs will remain relatively low (around 1000 m) in the warm sector adding to tornado concerns. The big question is if and when storms will be able to transition to SFC based, thereby increasing the tornado threat. There is a chance the initial convective area will be able to transition to SFC base by early afternoon across the east assuming they are still ongoing, but the bigger threat will likely occur as the area recovers from morning storms in the aftn and evening. Assuming the area is able to recover from morning storms, severe parameters are extremely impressive for Monday afternoon and evening. It shouldn't take much of a break to allow rounds 2 and 3 to re-fire in the afternoon and possibly again in the evening (a little further east each time), but there is also some concern wrt warm H7 temps promoting a deep stable layer and this will also have to be watched. In addition to the above mentioned shear, models show CAPE remaining very high (near or >3000 j/kg) in the warm sector SE of a developing SFC low and triple point. There is pretty good model agreement that a SFC low and triple point will develop across the area, but all over the place wrt the location of the low, warm front to its east, cold front to the west and dry line to the south. The trend has been for the triple point to develop further southeast in some CAMs, but even those CAMs keep the SE corner of the Panhandle in enough warm sector area to be concerning for supercells, with very large hail and tornadoes possible. Toward evening, we expect a transition to a linear event, but this may be in the far eastern Panhandle. Unfortunately, some of these details will not be clear until see see whites of its eyes on analysis and satellite tomorrow afternoon after the first round of storms ends. Bottom line, the enhanced to moderate SVR risk for much of the region tomorrow (favoring the east) is well founded although somewhat conditional on a few things coming together. That said, based on what we know now is that there is a potential for a significant severe event tomorrow with tornadoes possible (possibly large tornadoes). Gittinger && .LONG TERM... Cooler temperatures on Tuesday before returning back to the 80s for a daytime high on Wednesday. A blocking pattern to setup over Tuesday and Wednesday with a high over the southeast into the Gulf of Mexico and a trough over the west coast states. This will bring chances for several rounds of showers and thunderstorms Thursday through the weekend. Tuesday morning showers and thunderstorms will have moved off to the east out of the CWA. The associated midlevel low will move to the north as the leading edge of the h5 trough caries the thunderstorms out of the area. Cooler drier air will dominate the CWA on Tuesday with breezy west to southwest winds. A lee side low will develop over eastern Colorado and western Kansas early Tuesday and will tighten its pressure gradient going into the afternoon. This is when winds will pick up to near 30 to 35 mph gusting up to 45. Confidence in where the stronger winds will be in the Panhandle is low at this time. As of right now guidance is suggesting the southwest Texas Panhandle will see the higher end of these winds. Dewpoints will have fallen to the 20 and 30s on Tuesday and will bounce back to the 50s and 60s late Wednesday night. Wednesday will bring winds back to the southwest to south. The downslope flow, mostly clear skies and h85 temps around 26 degrees Celsius will bring temperatures back to the mid to upper 80s on Wednesday. A surge of moisture will return late Wednesday night into Thursday morning as an h5 high pressure system builds over parts of the southeast US and Gulf of Mexico. This high pressure will bring moisture in from the gulf through to west Texas then up to combined Panhandles. A low pressure system to the northwest will help with this as well and keep us under some decent moisture transport for some time. Guidance is suggesting that this pattern is going to stick around through the weekend giving us multiple rounds of showers and thunderstorms. Severe thunderstorms cannot be ruled out especially for Thursday night when the dryline forms over the central combined Panhandles splitting the west and east CWA. Instability and shear look to be present for the eastern half of the CWA. Will have to revisit the details Thursday through Sunday as we get closer. Hoffeditz && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 58 81 50 72 52 / 60 80 50 5 5 Beaver OK 56 68 53 73 53 / 50 90 70 10 5 Boise City OK 51 71 47 70 48 / 70 70 40 5 5 Borger TX 60 81 53 74 54 / 50 80 50 5 5 Boys Ranch TX 57 83 52 73 51 / 60 70 30 5 5 Canyon TX 58 83 51 73 52 / 60 70 40 5 5 Clarendon TX 59 79 54 75 54 / 50 80 80 5 5 Dalhart TX 53 77 49 71 48 / 70 70 30 5 5 Guymon OK 55 71 49 74 50 / 70 90 50 5 5 Hereford TX 57 83 50 72 51 / 50 50 30 5 5 Lipscomb TX 58 71 55 74 54 / 50 90 80 10 5 Pampa TX 58 76 53 73 53 / 50 90 70 5 5 Shamrock TX 60 75 58 75 54 / 40 80 90 10 5 Wellington TX 61 78 59 77 56 / 30 80 90 10 5 && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 88/36