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fxus63 kgid 282344 
afdgid 


Area forecast discussion 
National Weather Service Hastings NE 
644 PM CDT Thursday Aug 28 2008 


Aviation...00z taf. Surface high pressure will settle into 
central Nebraska tonight with VFR conditions expected at kgri. 


&& 


Previous discussion... /issued 254 PM CDT Thursday Aug 28 2008/ 


Short term...latest water vapor imagery from this afternoon shows a 
relatively flat upper pattern across the western and central Continental U.S. 
With a broad/Flat Ridge sitting from the Desert Southwest into the 
central and Southern Plains. Riding across the top of this ridge is 
a fast west to northwest flow regime with several small wave 
embedded within this flow pattern. Quick examination of surface observation 
reveals a cold front stretching from east central Iowa into northeast 
Kansas and the Oklahoma Panhandle. This boundary has been pushing 
steadily south through the day with much drier air advecting in 
behind the front with dewpoints in the middle 30s to lower 40s seen 
over western and north central Nebraska. 


As the area heads into tonight...the aforementioned front will 
continue to slide south before stalling near the Oklahoma...Kansas 
border by sunrise on Friday. This will allow much drier and hence 
stable air to invade the entire forecast by early evening. The NAM 
does reveal some weak instability existing in the 850-700mb layer 
over north central Kansas through most of the evening to early 
overnight hour...but inhibition is shown to remain strong enough and 
with little sign of a low level jet...it appears this instability will remain 
capped. Given this setup...will leave the forecast area dry for 
tonight and with a clearing sky...winds turning light and much drier 
air in place...will aim for some of the coolest lows of the season 
up to this point with readings ranging from the middle 40s near 
Ord...to the upper 50s near Beloit. 


Quiet weather pattern is expected to continue over the area Friday 
into Friday night as the front remains stalled out near the 
Oklahoma...Kansas border. Although the models do advertise some 
weak Theta/east advection around 850mb along with some modest elevated 
convective available potential energy of 300 to 500 j/kg between 850-700mb working into north 
central Kansas Friday afternoon to evening...appears better forcing 
for convective initiation will stay south of the forecast area. 
Based on this setup...will keep dry forecast Friday into Friday 
night. Temperature wise...good mixing should allow for highs in the 
middle to upper 80s on Friday. 


Long term...12z Saturday through Thursday. Warm and generally dry 
conditions still the theme for the Friday through Monday timeframe. 
Upper ridge is in place over the region on Saturday...while at the 
surface high pressure slides eastward while the Lee trough deepens 
to the west. This will tighten the pressure gradient across the 
region...driving increased southerly low-level winds and attendant 
warm air advection which combined with upper ridging will boost high temperatures 
into the upper 80s to lower 90s. Models are hinting at the 
possibility of some weak shortwave ripples drifting about the area 
on Saturday along with some weak 850 mb Theta-E advection. Thus cannot 
totally rule out a stray shower or thunderstorm...but at the same 
time chances of this look low enough to keep out of the forecast. 


The upper ridge slides east Saturday night as the next upper trough 
pushes onto the West Coast. This leaves the plains under a warm 
southwest flow aloft in between the two dominant pressure systems 
Sunday and Monday...as the western trough continues its eastward 
push across the intermountain west. Surface winds will be a bit 
breezy Sunday and Monday /and Saturday for that matter/. The warm 
temperatures will continue through Monday ahead of the approaching 
system...with highs reaching around 90 and lows in the 60s. The dry 
conditions should hold through the daytime hours on Monday...with a 
slight chance for thunderstorms returning to at least the northwest 
County Warning Area Monday night as the trough begins to lift more northeast through 
the northern rockies...sending a cold front southeast to near the 
northwest County Warning Area border by early Tuesday morning. The upper trough will 
lift northeast into the northern plains on Tuesday...while the 
surface front pushes through the forecast area. With the upper 
forcing staying primarily north of the area...the surface front and 
any middle-level frontogenesis will be the main player for our precipitation 
chances. May see some precipitation linger into Tuesday night across the 
east/southeast depending on frontal timing...but overall nature of 
the system looks fairly progressive. Cooler air will be ushered in 
with the front on Tuesday...with highs on Wednesday and Thursday 
expected to reach the upper 70s to lower 80s. Surface high pressure 
settling in behind the front should keep it dry Wednesday and 
Thursday. 


&& 


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


$$