Area forecast discussion
National Weather Service Norman OK
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 73 55 80 61 / 90 10 10 20
Hobart OK 75 54 87 61 / 40 10 10 20
Wichita Falls Texas 76 57 89 64 / 90 10 10 10
gage OK 78 51 85 56 / 10 10 20 20
Ponca City OK 75 53 79 57 / 30 10 10 20
Durant OK 77 60 85 64 / 100 40 10 10
&&
Oun watches/warnings/advisories...
OK...none.
Texas...none.
&&
$$
84
