280 FXUS64 KAMA 241132 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 532 AM CST Tue Nov 24 2020 .AVIATION... 12Z TAF Cycle IFR to MVFR conditions this morning at the Amarillo and Dalhart TAF sites will become VFR after 14Z to 17Z today. MVFR conditions at the Guymon TAF site will prevail until after 00Z to 02Z Wednesday when VFR conditions return. Showers and thunderstorms may impact the Guymon and Dalhart TAF sites after 19Z to 21Z today resulting in IFR to MVFR conditions. At this time, the showers and thunderstorms are not forecast to impact the Amarillo TAF site but this will need to be monitored closely in case the showers and storms develop further south. Blowing dust at the Amarillo TAF site may reduce visibilities after 20Z today. Southwest to west winds 20 to 25 knots with gusts near 35 knots will shift to the northwest after 18Z to 22Z today. The northwest winds will diminish to around 10 to 20 knots after 05Z to 10Z Wednesday. Schneider && .PREV DISCUSSION... /Issued 411 AM CST Tue Nov 24 2020/ SHORT TERM...Today and tonight. Very dynamic closed upper low over the Four Corners region this morning will approach the Panhandles by late today and this evening. Perturbations in the southwesterly upper flow ahead of the upper system will trigger isolated to scattered convection across the forecast area this morning through this evening. Best chances for convection will be mainly across the northeastern and eastern Texas Panhandle and the central and eastern Oklahoma Panhandle. Some storms could become severe mainly across the northeastern portions of the forecast area between about 19Z to 21Z today and 00Z or so Wednesday with large hail and damaging winds being the primary threats along and just ahead of a cold front. The cold front will advance south and east this morning as a surface low tracks out of far southeastern Colorado and far southwestern Kansas. The cold front should push into the northwestern portions of the Panhandles by mid to late morning and then across the remainder of the forecast area between 21Z today and 00Z Wednesday. Convection expected to linger into the evening hours across the northeastern Panhandles. With the strong cold air advection following the passage of the front, the rain may change over to or mix with snow mainly across the Oklahoma Panhandle and northwestern portions of the Texas Panhandle. Precip expected to end between 03Z and 06Z Wednesday as the main upper trough exits east away from the forecast area with decreasing cloudiness. 850 mb low level southerly jet 40 to 50 knots early this morning will mix down to the surface as skies begin to clear from southwest to northeast this morning. West and southwest winds will increase to around 25 to 30 mph with gusts near 40 to 45 mph by mid to late morning starting over the southwest and south central Texas Panhandle and then spreading north and east across the remainder of the forecast area by this afternoon. Patchy or areas of blowing dust will likely develop along and south of the Interstate 40 corridor across the far southern Texas Panhandle. Winds will remain strong and gusty following the passage of a cold front and will shift to the northwest and north. Winds will gradually diminish by late evening and overnight tonight. Schneider LONG TERM...Wednesday through Monday. Generally benign weather is anticipated Wednesday. The next cold front is slated to move across the OK and TX Panhandles on Thanksgiving Day. This frontal passage is in advance of another upper level storm system which is expected to affect the area Friday night through Sunday morning, the degree of which remains in question this far out in time as medium range models are still not in good agreement handling this feature. The 00Z GFS remains consistent in dragging a highly positively tilted upper level trof across the region Friday and Friday night and brings no precipitation to the area. Both the 00Z ECMWF and 00Z CMC models remain consistent as well in digging an upper level shortwave trof south southeastward and developing a closed upper level low pressure system south of the four corners region by late Friday afternoon, then tracking it eastward across our forecast area Saturday into Sunday morning. The 78 to 84 hour panels of the 00Z NAM are also hinting at a potential closed upper level low near the four corners region on Friday. Overall, the ECMWF rmmains the relatively wettest model while the GFS is driest. Given these medium range model discrepancies this far out in time, have gone with the consensus NBM pops and temps from Wednesday through Monday. Since the pattern is expected to amplify some, would not be too surprised if some semblance of a closed low develops in the vicinity of the four corners region during the time period discussed above if separation occurs between the northern and southern streams. The NBM appears to have captured this possibility with slgt chc to low end chc pops for Friday night through Sunday morning a good compromise at this time. Based on the progged atmospheric temperature profiles for this possible storm system, the potential exists for some sort of wintry precipitation, or at least a mix later Friday night into Saturday morning, and then again Saturday night into Sunday morning. Details on this possible storm system should become better defined as time gets closer, if the closed low scenario were to verify. However, if the GFS ends up verifying, no precipitation would occur Friday night through Sunday. Dry weather is anticipated Sunday afternoon and Monday. 02 && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 11/2