046 
fxus63 klbf 102128 
afdlbf 


Area forecast discussion 
National Weather Service North Platte NE 
328 PM CST Wednesday Mar 10 2010 


Synopsis... 
double 500 mb low over the South Dakota and northern Nebraska with 500 mb 
low over Oklahoma. As seen in infrared. 


&& 


Discussion... 
models in good agreement today and have good confidence in the 
forecast. GFS and NAM both picking up on precipitation over 
southwest Nebraska this afternoon. Have upped probability of precipitation tonight across 
southwest and north central as 500 mb lows swing back to the east. Quantitative precipitation forecast 
on the low side of HPC most places will see an inch or less of 
snow tonight. Thursday will be more interesting as low over 
Oklahoma turns north and deepens as energy from the Dakota system 
is absorbed combined. Temperatures will remain in the 30s on 
Thursday and Friday as colder air from the northwest is drawn into 
the backside of this system. Have undercut guidance by around 5 
degrees with 850mb temperatures -3 to -5c and 700-850mb 
thicknesses falling into the 520 to 530 range tonight and 
continuing through Friday. Strong deformation zone with abundant 
lift and strong pressure gradient will see deteriorating 
conditions through the day Wednesday into Friday especially over 
north central. Will issue a Winter Storm Watch for north central 
Nebraska east of a line from Ainsworth to Broken Bow where 
significant snow accumulations are possible with the system 
through the night Friday. The question has been the amount of cold 
air with the system. Time of season with calving operations across 
the area and windy conditions expected and a significant amount of 
snowfall believe justify the watch. Wind Advisory possible for 
portions of western Nebraska Thursday and Friday with tight 
pressure gradient. System to wind down Friday night into Saturday 
with some sun on Saturday. With another southern stream system 
moving onto the plains Sunday night into Monday both GFS and Euro 
are bringing some precipitation to western Nebraska. Have left 
silent probability of precipitation for now. Temperatures warming into the 50s through middle week. 


&& 


Aviation... 
mostly MVFR conditions are expected for western and central Nebraska 
tonight into Thursday morning...including the klbf and kvtn taf 
sites. It is possible that IFR may be experienced in any areas of 
snow. Surface winds will be north at 10 kts...increasing to 15 kts with 
gusts to 25 kts after 06z Thursday. 


&& 


Hydrology... 
hydrology concerns continue over north central Nebraska where the 
Elkhorn river is out of its banks. Some reprieve for north central 
today as they have received little precipitation. Hydrology 
concerns return Thursday evening with expected quantitative precipitation forecast. 


&& 


Lbf watches/warnings/advisories...none. 
&& 


$$ 


Short term/extended...power 
aviation...Taylor 
hydrology...13