Severe weather threat Friday, winter weather Saturday

(TULSA, Okla.) During the day Friday precipitation well above the seasonal normal in the 1 to 1.5 inch range along with dewpoints climbing into the 60s ahead of the frontal boundary will help set the stage for widespread heavy rainfall, as well as severe weather across the County Warning Area (CWA). The greater potential is expected starting Friday afternoon and continuing into Friday night. Conditions will aid in storms developing into more of a line segment mode. This will allow for damaging winds as well as a potential for QLCS tornadoes to be the main threats. Any storms that can remain discrete could have the potential for all modes of severe weather with damaging winds, large hail and also a tornado threat. A little more directional shear across far Southeast would have the greater potential for the large hail threat. With the parallel flow along/ahead of the cold front, training of storms will be possible- which will create the potential for flash flooding conditions as well as mainstem river flooding. Widespread rainfall in the 2 to 4 inch range with locally higher amounts up around 6+ inches are possible. The greater of these amounts look to be south of Interstate 44., especially over the Illinois, Poteau and Kiamichi River basins where moderate to near major flooding is possible. NWS will continue with the current flash flood watch as is for locations along and south of I-44. The cold front finally gets a push into Northeast Oklahoma Friday afternoon and through Northwest Arkansas late Friday evening/overnight Friday night as the main upper low shifts eastward into Texas. Behind the cold front much colder air is forecast to filter into the region Friday night which will allow for precipitation to transition over to a wintry mix of freezing rain and sleet into Saturday morning from northwest to southeast. The greater wintry mix is expected across Northeast Oklahoma before the nose of warmer temps aloft can be eroded. Ice accumulations of a few hundredths of an inch will be possible with to up toward a tenth of an inch for some location along the Oklahoma Kansas border. Surface temps will continue to fall Friday night through much of the Saturday as the upper low shifts east into the CWA and then Northeast into Missouri Saturday afternoon. By Saturday afternoon temperatures in the 20s to mid 30s are forecast from north to south. These temperature profiles combined with moisture wrapping around the upper low will aid in a transition to all snow during the day Saturday from west to east before tapering off and exiting by Saturday evening. Also behind the exiting low, gusty northerly winds in the 20 to 30+ mph range will be possible which could create areas of blowing snow Saturday morning. At this time, snow accumulations of 1 to 3 with locally higher amounts could be possible along and north of I-44 with around 1 inch or so for far Northwest Arkansas before the precip ends. With these amounts and also the possible ice amounts a winter storm watch will be issued across parts of the Oklahoma Kansas border in Northeast Oklahoma Friday night into Saturday.