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430 FXUS64 KAMA 201217 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 717 AM CDT Mon Sep 20 2021 .AVIATION... The low level jet is shifting east and LLWS in AMA has not be extended in the 12Z TAF. Fast moving front has cleared GUY and will move across DHT soon before reaching AMA around 15Z. Other than breezy NW-N winds today, no significant impacts/weather are expected with the frontal passage. Dry low levels will promote VFR conditions. There is a chance for elevated thunderstorms between 6Z and 12Z tonight in the northeast Panhandles. The probability of these impacting GUY is too low to include in the TAF. Gittinger && .PREV DISCUSSION... /Issued 314 AM CDT Mon Sep 20 2021/ SHORT TERM...Today through Tuesday... Well advertised and anticipated cold front has been trucking across NE CO at around 42 mph and it will enter the WRN OK Panhandle around 11Z this morning which is a little ahead of most models schedule. There is still some minor timing differences regarding the progression from there based on how much it slows down in the aftn, but the general consensus is that it will be at a minimum near I-40 by 18Z. Faster models (like HRRR which seems to have good handle) and the current forecast show it just about clearing the entire CWA at that point. CAA is pretty weak initially and the coldest air is lagging a bit behind the initial SFC boundary. So southern areas still should reach the 90s before the cooler air really begins to reach the area in the evening as the strongest pressure rises occur. It will be breezy to perhaps windy, especially across the northern areas behind the front, but not anticipating advisory level winds. WRLY low level winds in advance of the front will limit low level moisture (and help temps soar quickly south of the front) and any storms along and ahead of the boundary are expected to remain just south and east of the CWA. That said, good moisture advection is forecast in the H7-H6 layer across the NE Panhandles ahead of an H7 S/WV. This moisture will pool up along a weak area of H7 frontogenesis which forms as the base of a robust mid-upr level trough moves across the plains. There is a brief window where large scale lift assoc with the upper trough and H7 convergence may lead to isolated to scattered elevated showers and maybe even an elevated TSTM as NAM forecast soundings show uncapped CAPE just shy of 1000 J/KG above H7. That all said, models have significant differences regarding the degree the H7-H6 layer moistens, the amount of elevated CAPE, as well as the strength of the frontogenesis/convergence. Therefore POPs are only 10-30 percent (highest in far NE) between midnight and 6 am Tuesday to cover this possibility. NBM lows Tue are leaning toward the higher end of MOS, which makes sense given CAA will drive lows and fact that we will remain mixed overnight. Winds will decrease a bit early Tuesday morning but will likely increase again to near breezy levels with better mixing in the morning before weakening again in the aftn as the SFC high center approaches. Tuesday will be the coolest day with highs in the 70s area wide. The middle road NBM values for highs look good. Gittinger LONG TERM... Surface high will slide across the Panhandles early Wednesday morning. This will allow for light winds and with clear skies it should allow for good radiational cooling. The surface high builds into the south-central Texas Panhandle just before sunrise. This may allow for the coolest temperatures to be across the southwest and south-central Texas Panhandle. The "normally" cooler areas across the northwest CWA may have a return to south and southwest winds which may keep temperatures from falling to their complete "potential". Time will tell, if the high builds in more across the northwest CWA, then some upper 30's would not be out of the question in these areas. An upper level ridge then builds across the Panhandles through Thursday which will allow temperatures to warm to above normal by Thursday. The high will move out of the way to allow an upper level trough to move from south-central Canada into the Great Lakes by Friday. This should allow a cold front to move across the Panhandles on Friday. The models do not agree on how strong this front will be, so the high temperature forecast may be tricky on Friday. At any rate, any cool down from the front on Friday will be short as the upper level trough stays progressive and high pressure moves back across the Panhandles for Saturday and Sunday. && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 88/15