747 
fxus64 ktsa 202302 
afdtsa 


Area forecast discussion 
National Weather Service Tulsa OK 
602 PM CDT Sat Mar 20 2010 


Aviation... 
concerning taf sites ktul/krvs/kmlc/kxna/kfyv/kfsm. 
For the 0z tafs... snowfall... with reduced visibilities and low 
ceilings will continue across the region overnight and into 
Sunday. Strong and gusty northerly winds will continue as well. 
All taf sites will likely remain in IFR conditions or worse throughout 
the forecast period. 




&& 


Previous discussion... /issued 341 PM CDT Sat Mar 20 2010/ 


Discussion... 
round one of the Spring 2010 winter storm appears to be wrapping 
up with a large dry slot invading eastern Oklahoma...but not 
before dumping 2-5 inches of snow over parts of northeast 
Oklahoma. Freezing line currently near Miami-Antlers and inching 
ever closer to northwest Arkansas. All rain so far to the east of that. 
Some light icing was noted this morning but any additional threat 
of that is waning as warm nose seen at ksgf sounding has 
significantly eroded per 18z sounding. 


Round two still looking troublesome this evening through much of 
Sunday as upper low in the process of cutting off over northwest Texas/SW 
Oklahoma. Forecast track expected to bring the low slowly east 
near the Red River valley through Sunday with further deepening as 
it tracks toward the Mississippi Valley by late in the day. This 
process likely to wrap considerable warm air into the east side of 
the low and this presents some issues with the final snow amounts. 
Models will likely continue to struggle with this through the 
event but main effect appears keeping snow amounts down 
considerably over the far eastern sections of the forecast area. 
Will stay the course with the Winter Storm Warning through Sunday 
but have trimmed back snow amounts from fyv-fsm east. Temperature 
forecast will also be a problem as many places might be at their 
coldest now with steady or even a slow rise tonight... plus being 
impacted by the location/duration of the heaviest snowfall. 
Forecast temperatures more reflective of raw surface temperatures vs mav/met numbers 
through Sunday. 


System will finally move out Sunday evening with a rapid decrease 
in clouds from the west overnight. This will lead to a very cold 
night Sunday morning with temperatures likely several degrees colder than 
guidance. This being late March temperatures will recover quickly... 
especially by Tuesday when most areas back into the 60s and lower 
70s...thus completing the roller-coaster ride. 


Next system brings a good chance of rain and thunderstorms 
Wednesday night and cooler temperatures for Thursday...looks warm again 
by next Saturday. 


&& 


Tsa watches/warnings/advisories... 
OK...Winter Storm Warning until 7 PM Sunday for okz049-okz053-okz054- 
okz055-okz056-okz057-okz058-okz059-okz060-okz061-okz062- 
okz063-okz064-okz065-okz066-okz067-okz068-okz069-okz070- 
okz071-okz072-okz073-okz074-okz075-okz076. 


Arkansas...Winter Storm Warning until 7 PM Sunday for arz001-arz002-arz010- 
arz011-arz019-arz020-arz029. 


&& 


$$ 


Short term...99 
long term....99 
aviation...06