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fxus65 kpub 131028 
afdpub 


Area forecast discussion 
National Weather Service Pueblo Colorado 
428 am MDT Monday Oct 13 2008 


Short term... 
(tonight and monday) 


Short term concerns are precipitation chances and temperatures with 
broad upper trough remaining across the region. 


Current water vapor imagery and RUC upper air analysis continues 
to indicate moderate to strong dry southwest flow aloft across the 
area as broad upper trough continues to elongate across northern 
rockies through the Desert Southwest with associated jet cores 
lifting out across southeast Colorado and digging across the western 
Great Basin at this time. At the surface...cold front has finally moved across 
all of southeast Colorado with 2-3mb pressure rises being realized across 
eastern Colorado as high pressure builds across the northern High 
Plains. Satellite and surface observation indicating low VFR and MVFR ceilings 
across the eastern mts and plains and mostly clear conditions out 
west with regional radars indicating a few weak echoes streaming 
across the far eastern plains and western Kansas at this time. Current temperatures 
in the teens and 20s across the higher terrain with mainly 30s and 
40s across the eastern plains. 


Today...with mesonet readings indicating temperatures in the upper 
20s and lower 30s across northern portions of El Paso County early 
this morning...will keep current freeze warning in tact through 9 
am. Models continuing to have a hard time with NAM and GFS overdone 
with quantitative precipitation forecast early this morning over the plains. However...have kept 
isolated to scattered probability of precipitation across the far eastern plains associated 
with 700 mb baroclinic zone continuing to lift across eastern Colorado 
this morning. Have kept isolated probability of precipitation across the mts and eastern 
foothills this afternoon with surface-700 mb flow becoming more easterly as 
high pressure continues to build across the High Plains and weak Lee 
troughing developing across the I-25 corridor. Soundings indicating 
clouds slowly diminishing across the eastern plains through late 
morning with partly sunny skies for the afternoon...save along the 
lower eastern slopes where believe stratus may hang in place through 
the greater part of the day. Have compromised between the warmer mav 
and cooler met guidance...though have stayed closer to the cooler 
side along the eastern slopes. 


Tonight...models continue to struggle with movement of broad trough 
with latest GFS closer to the European model (ecmwf) in developing a closed low 
across northern Arizona through tonight...though both models are 
slower in upper low development than previous runs. This would allow 
for deepening south to southeast flow middle level flow and better 
chances of overrunning precipitation across the southern reaches of the 
state and have trimmed back probability of precipitation to match across the northern areas. 
Temperatures to remain a challenge as with upslope flow continuing...would 
tend to see stratus developing keeping temperatures up once again 
across the eastern plains...and have stayed closer to the warmer 
side of guidance. Could however see pockets of at or subfreezing 
temperatures across portions of the I-25 corridor and eastern plains and 
will let the day shift evaluate further runs to see if highlights 
are needed. -Mw 


Long term... 
(tuesday through sunday) 


Main question is northward extent of precipitation on Tuesday...with 
how quickly temperatures warm up Wednesday-Friday a secondary concern. In 
general...NAM a little farther south with the upper low than 
either GFS or European model (ecmwf)...thus it keeps the bulk of the heavier precipitation 
south of the area Tuesday. Given very dry air mass in the middle 
levels already in place over the area...plus prognosticated position of 
the cold front well south of the Colorado/nm border...suspect drier 
solution is the way to go at this point...especially over northern 
and western sections of the area. Kept the fairly sharp pop 
gradient in place through Tuesday afternoon...with likely probability of precipitation 
southeast corner...lowering to isolated over the Continental 
Divide and Teller County. Most of the plains will remain socked in 
with lower clouds through the day Tuesday...though areas north and 
west of kpub could clear by sunset...as subsidence and westerly 
700 mb winds develop. Nudged maximum temperatures down slightly on the plains 
Tuesday afternoon to fit better with neighbors. Precipitation ends over 
all the area by late Tuesday night...certainly could see a hard freeze 
over the plains if clouds clear quick enough. Warming begins 
Wednesday...with weak cold advection behind the departing surface low 
ending by 18z...allowing 700 mb temperatures to rise to near 4c by late 
afternoon under westerly flow aloft. Nudged previous forecast down 
a few degrees as middle 70s seemed rather optimistic on the 
plains...though readings near 70f certainly obtainable as surface 
winds become weakly downslope. Remainder of the forecast from Thursday 
Onward unchanged...with mild and dry Fall weather in store. 


&& 


Aviation... 
low VFR and MVFR ceilings expected to persist across the 
eastern mts and plains this morning with partial clearing through 
the afternoon. Patchy IFR ceilings possible across the lower eastern 
slopes with surface-700 mb flow becomes more easterly as high pressure 
builds across the northern and Central High plains. Could see low 
VFR and MVFR ceilings developing once again across the eastern plains 
tonight with increasing chances of showers across the southern 
border areas through the overnight. -Mw 


&& 


Pub watches/warnings/advisories... 
freeze warning until 9 am MDT this morning for coz084. 


&& 


$$ 


23/10