Area forecast discussion National Weather Service Norman OK 637 PM CDT Tuesday may 21 2013 Aviation...00z taf issuance... VFR conditions will prevail through the evening and overnight. Skies will continue to clear from west to east across western and central OK this evening as the upper level low continues to shift eastward this evening. Some scattered to broken middle level clouds will likely linger across northwestern OK through Wednesday morning before dry south/southwest flow takes hold through noon Wednesday. Light and variable winds through the morning hours will result in possible MVFR to IFR fog at aerodromes across central and southern Oklahoma. Increasing west/southwest winds Wednesday morning from southwest OK/western North. Texas into central OK will allow any widespread fog to lift quickly through sunrise. Jtk && Previous discussion... /issued 212 PM CDT Tuesday may 21 2013/ Discussion... the main forecast challenges for this package will be ongoing convection across Oklahoma and North Texas...and forecasting shower/storm chances over the coming week...which may hamper search and Rescue efforts in central Oklahoma. A strong upper level wave of low pressure is moving across the Southern Plains. Recent WV imagery shows a well pronounced dry slot developing west of an eastward moving line of strong to severe storms extending from just east of Holdenville...southward to near Tishomingo and Lake Texoma. At times...strong to severe wind gusts have occurred with this complex...and storms are likely to remain strong to severe. The threat for severe weather is expected to continue into the evening. In addition to the severe threat...persistent heavy rainfall has led to occurrences of flash flooding and possibly river flooding over parts of south central and southeast Oklahoma. Do not drive through flood waters if you come across them on the roadway! Further north...with cooler and drier air filtering into the region...and with expansive cloud shield and increasing stability...expect mainly light to moderate rain over most of northern and central Oklahoma...with occasional thunder. By tonight...most activity will have exited the region...with clouds hanging around southeast Oklahoma. With residual moisture in place...and surface high pressure moving in behind as passing front...patchy to widespread fog may develop...especially from central Oklahoma southeastward. Patchy dense fog may even develop near sunrise...as winds go calm...causing hazardous driving conditions. For the rest of this week...flat middle level ridging will build into Oklahoma and North Texas. With several small scale impulses moving along the northern periphery of the ridge...at least isolated shower and thunderstorm activity will be possible each day over the coming week. This will mainly be driven by diurnal heating. Rain chances will increase from this weekend into early next week...as a large upper storm system emerges into the Southern Plains. For now...will keep chance probability of precipitation or less through the entirety of the forecast period. Regarding search and Rescue operations in the south Oklahoma City metropolitan area...expect main impacts in the short term to be light shower activity...which will diminish by this evening. Any fog development that occurs tonight into tomorrow morning will make Rescue operations difficult. Cool morning temperatures and patchy fog will yield to mild temperatures and mostly clear to partly cloudy skies by early afternoon tomorrow. Again...at least a slight chance of storms will linger into the weekend...so personnel involved in cleanup and Rescue activities will need to monitor the weather situation closely over the coming days. && Preliminary point temps/pops... Oklahoma City OK 73 56 80 60 / 90 10 0 20 Hobart OK 75 53 87 60 / 40 0 10 10 Wichita Falls Texas 76 58 89 63 / 90 10 0 10 gage OK 78 48 85 56 / 10 0 10 20 Ponca City OK 75 51 80 57 / 30 10 0 30 Durant OK 77 59 85 64 / 100 30 0 10 && Oun watches/warnings/advisories... OK...none. Texas...none. && $$ 03/04/04