Scientific Forecaster Discussion
000 FXUS64 KOUN 112344 AFDOUN Area Forecast Discussion National Weather Service Norman OK 544 PM CST Wed Dec 11 2019 .AVIATION... 1200/1224 TAFs... High clouds will continue to increase, as a shortwave trough approaches the southern Plains from the west tonight. Modest moisture advection may result in areas of MVFR ceilings later this evening and overnight, mainly in and near WWR and CSM. Low level winds will also become rather strong after 4-5Z which will result in LLWS, especially around OKC/OUN/PNC. High clouds should decrease some Thursday with a south to southwest wind. && .PREV DISCUSSION... /issued 354 PM CST Wed Dec 11 2019/ DISCUSSION... For tonight, cloudiness will be increasing as a short wave trough passes through, with its associated surface low/boundary staying well north of our area in the Central Plains. The cloudcover along with increasing south winds keep nighttime temperatures a little bit warmer than last night. Will go with Superblend model for tonights temperature and it should also be breezy mainly across our northwest. Still expecting slightly warmer than normal temperatures in the short range of the forecast, with little change to the previous forecast values. Another short wave will be digging across the Central Plains on Friday night, which will push a dry cold front into the Southern Plains. With more Pacific based air initially coming in, we should not see a drastic temperature change behind the front for Saturday. However, a much deeper trough behind this system will start bringing in much colder Canadian based air beginning Saturday night into early next week. This next deeper system will also introduce low POPs of light snow across northern Oklahoma for Saturday night. Our POPs increase further southward on Sunday with light rain across the remainder of our area during the day. Increasing Gulf moisture across eastern Texas advecting into southeast Oklahoma may result in marginal instability for convection to develop, and is also supported by negative Lifted Index values. As a result, isolated thunderstorms have been introduce into the grids across southeast Oklahoma for Sunday. However, POPS are being kept low at this point since both GFS and the ECMWF remain in disagreement at least through Sunday night. The European model is consistently the wetter of the two medium range models, where the GFS runs stay dry in our area with QPF across the eastern half of Oklahoma for Sunday night. If the ECMWF solution is correct for Sunday night, then rain could change over to light snow across much of our forecast area. For now, any snow accumulations would be across far northern Oklahoma. The exact precipitation types may change as we get closer to the event. For Monday, a changeover to light rain as the system exits off to our east with a very subtle warming trend beginning. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 36 54 35 58 / 0 0 0 0 Hobart OK 35 55 32 61 / 0 0 0 0 Wichita Falls TX 34 57 36 61 / 0 0 0 0 Gage OK 39 57 30 61 / 0 0 0 0 Ponca City OK 38 55 34 57 / 0 0 0 0 Durant OK 33 55 36 58 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None.