461 
fxus63 koax 220811 
afdoax 


Area forecast discussion 
National Weather Service Omaha/valley NE 
311 am CDT Monday Mar 22 2010 


Discussion... 
quiet weather is dominating tonight as region lies under ridging. 
Subjective 00z upper air analysis indicates deep upper low centered 
in northern MS...progressing eastward. Trough was coming ashore in the Pacific 
northwest...with 500mb heat falls as high as 90m centered in or/ID. 
Between...weak ridging was in place across the central US. Weak low 
was also noted in the northern Gulf of California. Area radiosonde observations indicate 
very dry airmass in the region...with little moisture at any level. 
Gradient of temperatures at 850mb was in place across the central US...with 
warmer temperatures in The Rockies/High Plains and cooler closer to the 
upper low. Surface ridge at 06z extneded from western OK through eastern 
is/southeastern Nebraska/central Iowa into northern WI. 


Main forecast concern is simply temperatures for the next couple of 
days...followed by potential for system to skirt the southern County Warning Area around 
Wednesday/Wednesday nt. Temperatures today will be modulated by cirrus...as well as 
weaker winds /especially east/. Have knocked back temperatures a couple 
degrees in the east...but did bump up in the west where better 
mixing will occur. Weak and dry cold front will move through tonight 
as initial weak upper wave rolls across the northern plains. Given dry 
airmass in place...have little concern for precipitation...as even clouds 
will struggle to develop with relatively weak lift into dry air. 
Temperatures will be knocked down to slightly below norms though...as flow 
takes on a nearly component. Kept relatively strong gradient of temperatures 
from north to south on Tuesday as north is influenced by cold air 
advection during the day. 


Deeper wave is expected to move through the central/Southern Plains on 
Wednesday/Thursday as southern stream low ejects into the southwestern US...then interacts 
with second northern stream wave before sliding eastward. Current models 
keep system south of the County Warning Area...with the sernmost County Warning Area just on the northern 
fringe of the precipitation shield. GFS solution is further north than 
ECMWF/NAM...which are much further north than Gem. Have kept low 
probability of precipitation in the southern County Warning Area from Wednesday afternoon through Wednesday nt until there is 
better agreement...which hinges on interaction between northern and southern 
stream waves. Did take probability of precipitation out of Thursday as system pulls away to 
the east. 


&& 


Aviation... 
taf sites kofk/koma/klnk 


06z tafs 


VFR conditions at all taf sites through the period. Pressure gradient 
does increase this afternoon and we may see some gusts...especially at 
the ofk terminal...but these shld end by 21-23z. 


&& 


Oax watches/warnings/advisories... 
NE...none. 
Iowa...none. 
&& 


$$ 


Mayes/boustead