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Area forecast discussion 
National Weather Service Norman OK 
352 am CDT Sat Mar 20 2010 


Discussion... 
upper low is prognosticated to take a near-optimal track for heavy snow 
across northern-central-eastern OK as it moves from nm east-southeast-Ward 
along/near the Red River into the arklatex by Sunday morning. 
Multitude of precipitation types being reported with the initial 
transition this morning... but the changeover to snow should be 
more swift later today as dynamic cooling arrives ahead of the 
approaching upper low. We will add a few more counties in southeast OK to 
the warning... and the rest of the area not in the warning will go 
to an advisory for snow and blowing snow. The current expiration 
times are generous given that model qpfs begin shutting down the 
snow in the west/northwest by this afternoon. Later shifts will likely be 
hacking away at the warning/advisory areas as the snow tapers 
off. 


This event will likely bring okc to a new seasonal record for snow 
by the time it ends. It might have set more records than that had 
there been more cold air established over the area prior to the 
event. As it is... much of the early part of the event will be 
rain or mixed precipitation. There is also the consideration of blizzard 
or near blizzard conditions... and perhaps the need to upgrade to 
a Blizzard Warning. At this time we are not confident enough that 
wind speeds and visibilities will justify that... and since we 
have maintained emphasis on the winds and blowing snow from the 
beginning... we will stick with a Winter Storm Warning for now. 


Snow should wind down this evening over much of west OK and our Texas 
zones... and early Sunday over central OK. Snow cover will keep 
temperatures down for a while thereafter... but it typically does not 
linger very long this late in the season and so we will bring 
temperatures back up to more springlike levels again by around Tuesday. 
No signifcant changes in reasoning for middle-late week. Another 
system moves through around Wednesday-Thursday but looks weaker and with less 
cold air. 


&& 


Preliminary point temps/pops... 
Oklahoma City OK 31 27 37 27 / 100 40 20 0 
Hobart OK 31 23 40 27 / 80 10 0 0 
Wichita Falls Texas 35 28 44 30 / 80 30 0 0 
gage OK 32 24 45 20 / 70 10 0 0 
Ponca City OK 31 28 34 22 / 100 50 30 0 
Durant OK 44 31 38 31 / 100 60 40 10 


&& 


Oun watches/warnings/advisories... 
OK...Winter Storm Warning until 7 PM CDT Sunday for okz007-008-012- 
013-017>020-023>032-040>042. 


Winter Storm Warning until 7 am CDT Sunday for okz004>006- 
009>011-014>016-021. 


Winter Weather Advisory until 7 am CDT Sunday for okz037>039-044- 
045. 


Winter Weather Advisory from 1 PM this afternoon to 7 PM CDT 
Sunday for okz046-050>052. 


Winter Storm Warning from 1 PM this afternoon to 7 PM CDT Sunday 
for okz043-047-048. 


Winter Storm Warning until 7 am CDT Sunday for okz022-033>036. 


Texas...Winter Weather Advisory until 7 am CDT Sunday for txz083>090. 


&& 


$$ 


06/24