144 
fxus63 kgid 211728 aaa 
afdgid 


Area forecast discussion...updated 
National Weather Service Hastings NE 
1228 PM CDT Thursday Aug 21 2008 


Update...went for another round of updates to account for slowly 
diminishing clouds across the County warning forecast area. We are finally seeing a slow 
migration east of western edge...and some thinning/mixing out from 
the south. Models suggest far northeast County warning forecast area will be last to clear 
and that seems to be coming true based upon satellite trends. Made 
some slight modifications to afternoon temperatures with only 
around 80 likely for that far northeast County warning forecast area area. 


&& 


Aviation...18z taf. IFR ceilings should quickly rise to MVFR ceilings 
by 19z...and then VFR ceilings by 20-22z at kgri. Satellite and 
observation trends supporting the likelihood of improved 
conditions shortly. By evening...prevailing VFR conditions are 
expected. A short period of lowered visibilities in haze is possible 
near dawn Friday...but it should not be nearly as lengthy nor 
widespread as previous days. 


&& 


Previous discussion... /issued 629 am CDT Thursday Aug 21 2008/ 


Aviation...12z kgri taf. Stratus is showing up nicely on 
satellite and local observations. Will not be long until this 
stratus the terminal area. Reduced visibility will occur as well. 
Expect MVFR conditions perhaps intermittent IFR conditions early 
this morning. Ceilings may take a while to raise above 
MVFR...possibly not until afternoon. VFR ceilings should scatter 
by Thursday evening...but a bit of a gusty wind that develops in 
the afternoon from the south and should continue tonight. 
Visibility may once again be reduced late tonight...but this does 
not look it would be quite as likely as this morning...so for now 
have left this out of the forecast...especially since it is toward 
the end of the forecast. 


Previous discussion... /issued 355 am CDT Thursday Aug 21 2008/ 


Discussion...one more quiet day expected today before 
precipitation chances make a return to the County Warning Area. 00z upper air data 
and current satellite imagery show a low pressure system/trough 
continuing to move onto the western coast. Pattern across the 
central and east a bit more interesting...a ridge axis extends 
north through the Great Lakes region and into Canada with a 
trough over the far northeast...Fay continues to spin over 
Florida...and a weakening cut off low sits near the Kansas/OK/MO/AK 
borders. Not many changes at the surface...as large area of high 
pressure remains anchored over the Great Lakes/northeast with an 
area of low pressure/trough over the High Plains. Resultant 
southeasterly flow aiding in the northward transport of lower 
level moisture...and increase in stratus and haze/fog across the 
area. 


Though it will be a cloudy start to the morning...expect this will 
give way to partly cloudy/mostly clear skies this afternoon. Models 
continue to be in good agreement with the upper level low to the 
south and the evolution of the overall pattern today. Pacific northwest 
low/trough will continue to work its way east...with the Southern 
Plains low continuing to weaken...and eventually shifting 
northeast and becoming phased in with the main flow. This path 
expected to keep the best forcing and bulk of precipitation well 
to our east...so forecast stays dry through tonight. Looking at 
the surface pattern...really not many changes today. Large Great 
Lakes/northeast high continues to shift slowly east...with the 
High Plains low/trough strengthening ahead of the approaching 
upper level Pacific northwest system. This means continued southerly flow 
across the region...with speeds once again increasing to near 15 
to 20 miles per hour this afternoon. As far as temperatures go...expecting 
little difference from the past few days...with highs in the 
Lower/Middle 80s and lows tonight cooling into the Lower/Middle 60s. 


Wet weather makes a return to the region starting on Friday. Models 
in decent agreement as upper level and surface low pressure slides 
east/northeast across the US/Canadian border. A surface cold front 
gets pushed south into the County Warning Area Friday afternoon...and there 
continues to be good agreement with the front draped across the 
County Warning Area by 00z Saturday...providing a focus for thunderstorm 
development. There are slight differences with the onset of precipitation 
and whether capping holds things off until after 00z...but kept in 
slight chance mention across Nebraska counties during the 21-00z 
timeframe. With the front here and decent instability present...anywhere 
from roughly 1500-2500 j/kg depending on the model...cant 
completely rule out isolated/scattered storms before 00z. And even 
with instability present...deep layer shear is less than 
stellar...so a few storms could be on the strong side but not 
overly concerned about severe weather. Better chances come Friday 
evening/overnight...with the County Warning Area getting a bit of help from an 
increased southerly low level jet. Looking at temperatures...Friday also expected 
to be the warmest day of the short term period...with better 
mixing ahead of the front helping highs reach into the middle/upper 
80s across central/northern areas and Lower/Middle 90s possible 
further south into Kansas. 


Chances for precipitation expected to linger on into the weekend. 
Main upper level/surface low pressure system in Canada continues to 
slide northeast...with surface front losing its push and becoming 
stalled out. Slight model differences exist as to just where the 
front sits...but all have it either right over or in very close 
proximity to the County Warning Area...with best chances for precipitation across the south. 
Trended high temperatures down a few degrees into the lower 80s 
north/middle 80s south with precipitation and clouds lingering around. 


No changes made to Sunday and beyond. 


&& 


Gid watches/warnings/advisories... 
NE...none. 
Kansas...none. 
&& 


$$