Area forecast discussion National Weather Service Norman OK 1230 PM CDT Tuesday may 21 2013 Aviation... the main concern for this forecast are the thunderstorms currently moving east across Oklahoma and impacting kokc...koun...and ksps. These storms should move out by 20z. Showers may linger longer. Outside areas of convection...winds should remain fairly light throughout the taf period. Some br will be a possibility toward sunrise at our southern and eastern sites. && Previous discussion... /issued 1210 PM CDT Tuesday may 21 2013/ Update... made brief updates to the going forecast this morning. Probability of precipitation were significantly increased over central and southern Oklahoma as ongoing complex continues to move eastward. Current thinking based on recent high resolution models is that most activity will end from west to east through middle afternoon. Still...heavy rainfall, frequent lightning, and small hail will be a threat to ongoing search and Rescue operations in central Oklahoma. Severe thunderstorms will have a greater window of development over south central and southeast Oklahoma...nearer the greater instability. Previous discussion... /issued 628 am CDT Tuesday may 21 2013/ Discussion... 12z aviation discussion follows.... Aviation... a very slowly moving cold front has lit up with convection overnight...and these storms are likely to continue along the front all day and into the evening. The front...and the area of storms...should move slowly southeast the rest of the day. However...some northward development is not out of the question this morning. In any case...thunderstorms and rain should remain S of kpnc...kgag...and kwwr. The storms are expected to move southeast of our forecast area this evening...leaving clearing skies and light winds at most sites. Recent rains suggest that some br is a good possibility toward sunrise at all but our western sites. Winds will turn around to S overnight or tomorrow morning. Previous discussion... /issued 322 am CDT Tuesday may 21 2013/ Discussion... early model divergence and periodic convective activity will lead to a very low-confidence forecast...especially after Saturday. The synoptic-scale storm system that has plagued Oklahoma and North Texas with severe weather over the past couple of days has shifted slightly to the southeast. Storms are likely to continue today...with primary emphasis across the southeast parts of our forecast area. The risk of severe storms will be mainly confined to the southeast half of Oklahoma...and North Texas from Wichita Falls east. The cooler air behind the surface cold front will finally move farther south for Wednesday...reducing the chances for storms for a day or two. Southerly flow will bring warmth and moisture back into North Texas and Oklahoma late this week. This will bring another series of chances for rain as a long parade of shortwave troughs pass over the Southern Plains within the longwave trough anchored over western North America. Even if the model forecasts were in better agreement...the timing of such waves is difficult in this time frame. && Preliminary point temps/pops... Oklahoma City OK 55 80 61 76 / 10 10 20 30 Hobart OK 54 87 61 82 / 10 10 20 30 Wichita Falls Texas 57 89 64 85 / 10 10 10 20 gage OK 51 85 56 75 / 10 20 20 40 Ponca City OK 53 79 57 73 / 10 10 20 20 Durant OK 60 85 64 82 / 40 10 10 20 && Oun watches/warnings/advisories... OK...none. Texas...none. && $$ 99/99/14