613 FXUS64 KAMA 110455 AAB AFDAMA Area Forecast Discussion...UPDATED National Weather Service Amarillo TX 1055 PM CST Wed Mar 10 2021 .AVIATION... For the 06Z TAFs, a weak cold front will continue moving across the region tonight. North winds behind this boundary will become southeast late Thursday afternoon and evening. In addition, some high level clouds are also expected in advance of an approaching upper level storm system, which will begin to affect the area after this fcst period. 02 && .PREV DISCUSSION... /Issued 557 PM CST Wed Mar 10 2021/ AVIATION... For the 00Z TAFs, winds will rapidly diminish by early this evening. A weak cold front will move across the terminal sites late tonight. Some high level clouds are also expected towards the end of this fcst cycle. 02 PREV DISCUSSION... /Issued 157 PM CST Wed Mar 10 2021/ SHORT TERM...This Afternoon through Tomorrow... An upper level disturbance is moving northeast across Nebraska, with an H25 jet of approximately 80 to 120 kts coincident with the dry slot shown on satellite. The cross barrier flow of this jet has caused westerly to southwesterly winds of around 20 to 30 MPH with gusts as high as 50 MPH (favoring the western Panhandles) to occur. A Wind Advisory is in effect through 6 PM CST as a result. Relative humidity values are mostly in the single digits and lower teens, and expected to remain close to those through about sunset. Details of fire weather conditions are covered in the fire weather section. Southwesterly flow aloft should continue into the overnight hours and into the day tomorrow. A weak cold front is progged to move into the northeastern Panhandles early tomorrow morning, and make it's way across the region through the day on Thursday. High temperatures are expected to drop about 10 degrees compared to today (lower 60s to lower 70s), with any precipitation chances expected to occur after the forecast period. Bieda LONG TERM...Thursday night through Tuesday night... GOES-16 water vapor analysis currently shows a mid to upper level low pressure system sitting off the coast of northern CA. This low pressure system is progged to move south along the coast of CA and end up over the far southeastern portion of CA into southern NV and western AZ by 18Z Friday. This system will be bringing in moisture from the Pacific late Thursday night. Over the Gulf of Mexico high pressure will be working to bring in moisture from the gulf up through southern to southwest TX as well. Cooler temperatures will be present across the Panhandles this weekend along with the chances for some severe thunderstorms. The best chances to receive beneficial rain fall will be Friday night into early Saturday. Going into Thursday night a surface cold front will move into the area from the NE, then quickly retreat to the north as warm moist air in the SE pushes northward. Dry air in the west will try and hang on to portions of western to southwest Texas Panhandle as these three different air masses battle over the FA. By Friday afternoon the dry air will make an advancement tightening up the dryline slightly along the eastern stack of counties in the eastern TX Panhandle. Overnight Thursday into early Friday thunderstorms will be possible mainly in the SE TX Panhandle with dewpoints near 50s to lower 60s. Not only will there be strong theta-e advection from the aforementioned systems, but there will be some upper level disturbances ejecting out from the low before the main dynamics move in Friday night. These perturbations are what introduces PoPs first to the far SE TX Panhandle early on Friday before the main system. Only have up to 30 PoPs before sunrise on Friday. The NBM suggest PoPs increase across the area going through the day on Friday. This will all depend on how far the dryline stays to the west during the day. But PoPs will increase going into Friday evening for the rest of the Panhandles. Instability Thursday night through Friday looks to be elevated. MLCAPE values look to remain below 900 J/Kg, but bulk shear values will be reaching 73 kts creating the possibility for some large hail up to an inch in diameter for Friday morning. By 00Z Saturday, things really start to get interesting. Model guidance is not in good agreement at the time though. Both the GFS and NAM have different solutions for the location of the triple point and its progression overnight Friday, from 00Z through 12Z Saturday. The NAM is showing the triple point around the far southwest Texas Panhandle Friday evening. It is suggesting a short period of uncapped SBCAPE around 800 to 1000 J/Kg. May not seem like much but at the same time surface to 1 km helicity is looking to be around 200 to 400 m^2 per s^2. Bulk shear will be around 80 kts. The NAM sig tor parameter is throwing out a value of 8. Now this is only one model solution, suggesting tornados could be possible across a small area Friday evening. Will have to watch closely as HiRes models come in in the short term. Severe weather will still be possible going through the day on Saturday but will be moving east as the dryline progresses. PWAT values suggest some heavy rain fall rates overnight Friday into Saturday as well. PWAT values are ranging from 0.70 inches in the west to 1.20 inches in the east which is well above normal for early March. Even if the NAM is correct and the cold front is south of Amarillo, moisture overrunning the front will create some decent showers and thunderstorms overnight Friday night. By 12Z Saturday the center of the H5 low is progged to be over the Four Corners Region and expand all the way down south to Mexico. The mid to upper level system will then track east through the day with showers ending in the western FA by Saturday evening. At the surface the dryline will progress east out of the area bringing in dry air once again with westerly downsloping winds. Showers and thunderstorms should be ending in the eastern zones by late Saturday. Early Saturday morning some areas in the western Panhandles have a chance to get cold enough to see some rain turn to snow but not cold enough to stick. Sunday trough Monday morning the NBM is giving 20 to 30 PoPs across the northern combined Panhandles from possible wrap around moisture. Monday through Tuesday there will be a dry period. Then Tuesday night a second mid to upper level low pressure system is progged to skim just north of the FA. Model guidance is diverging at this time with the GFS being the most progressive. The Canadian and EC are slower with also a more southerly track coming straight across the FA Tuesday night into Wednesday morning. Have stuck with the NBM PoPs leaving only a slight chance for the OK Panhandle and far northern Texas Panhandle. Hoffeditz FIRE WEATHER... A disturbance is passing north of the region, and cross barrier flow has created strong downsloping winds across the region. Wind speeds of around 20 to 30 MPH are being observed across the area, with the strongest winds favoring the western counties of the combined Panhandles. The strongest wind speeds and lowest relative humidity values are being observed presently with Red Flag Warning conditions being observed. RFTI values of around 4 to 7 should drop into the 2 to 6 range heading into the late afternoon hours. A Red Flag Warning remains in effect through 8 PM this evening, though there is a possibility that critical conditions could end sooner. Another round of elevated fire weather conditions behind a weak cold is expected tomorrow, though the contribution to the Red Flag Threat Index is nearly all due to the low relative humidities as winds are expected to be around 5 to 15 MPH. Bieda && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$