721 
fxus65 kpub 151515 
afdpub 


Area forecast discussion 
National Weather Service Pueblo Colorado 
915 am MDT Monday Mar 15 2010 


Update... 


Updated forecast to remove Winter Storm Warning for the southern sangre 
Delaware cristo mountains. 


&& 


Short term... 


The storm which was bringing the threat of heavy snow to the southern 
sangre Delaware cristo mountains has moved out of the area. Some light snow 
or light rain and snow is expected at times through afternoon over 
this area. No change to forecasts elsewhere. 


Long term... 


No updates at this time. 




&& 


Aviation... 


No updates at this time. 




&& 


Previous discussion... /issued 336 am MDT Monday Mar 15 2010/ 


Short term... 


(today and tonight) 


Currently...upper level storm system is located over western New 
Mexico and will track southeast through this afternoon into West 
Texas. Radar indicates snow continuing over the southern sangre Delaware 
cristo range this morning with areas of light rain and snow over the 
eastern plains. Low level flow has turned northerly across eastern 
Colorado with the exception of the southern I-25 corridor where 
northeasterly flow is aiding in continued upslope flow over the 
southern sangre Delaware cristo range. 


Went with a blend of the WRF/sref/NAM solutions which seem to have 
the best handle on current precipitation trends. Best forcing 
associated with the upper low is currently confined to northeastern 
New Mexico and the Texas Panhandle and will shift south through the 
morning hours. Easterly flow prognosticated by the models in the 850 to 
700 mb layer will continue through this morning along the 
Colorado/New Mexico border before turning northerly as the low 
tracks to the south. Expect snow to continue over the southern 
sangre Delaware cristo range and Raton ridge into early afternoon. 
Continued the Winter Storm Warning for the southern sangre Delaware 
cristos through middle morning with generally 1 to 3 inches over the 
lower elevations and up to an additional 5 inches over the higher 
terrain. Precipitation will come to an end across the plains this 
morning with the exception being Baca and Las Animas counties where 
light rain/snow will be possible through noon. The local WRF run 
hangs on to precipitation along the Colorado-New Mexico border 
through 20z with nothing more for this evening and tonight. NAM 
also indicating this with precipitation ending by 21z for the southern 
zones. Light snow will also continue through the morning hours for 
the western and central mountains with up to an inch of additional 
accumulation expected through this afternoon. Temperatures will be 
tricky and dependent on where clouds break this afternoon over the 
plains. Currently thinking upper 40s to near 50 north of U.S. 
Highway 50 where some sun will be possible by this afternoon. Over 
the southern zones...temperatures may struggle reach the 40s 
depending on how quickly precipitation exits the region and how long 
clouds hang around. 


High pressure over the Great Basin will begin to build eastward over 
The Rockies by Tuesday morning. This will allow for clearing skies 
over Colorado tonight. Model soundings indicating dry air in the 
lower levels which will help inhibit potential fog development for 
tomorrow morning. 88 


Long term... 


(tuesday-sunday) 


Main concern during this forecast period is Friday. 


In the meantime...ridge of high pressure will build aloft bringing 
pleasant Spring Time weather to the region. Temperatures Tuesday through 
Thursday on the plains should maximum out in the 60s with a 70 or two 
likely. Skies should generally be mostly sunny. 


By later Thursday...shortwave coming in form the Pacific northwest will be 
dropping into the state...and showers should start to ramp up by 
afternoon across the c mountain region. A surface low will begin to gin-up 
over the plains and we will likely see some increasing cloudiness 
over the plains. The front itself associated with the short wave 
will likely come across towards sunrise Friday and be through the County Warning Area 
by noon. 


As for precipitation...things looking a bit more promising for precipitation. As 
alluded to yesterday at this time...system is forecast to be a bit stronger on the 
GFS with 700 mb flow taking on a NE component. If this verifies...east 
slopes of S mountains may get some rain/snow with this event as lapse 
rates are forecast to be quite steep and we should see some convective 
showers over this region. Ec simulation run on the other hand is not 
so promising showing just northwest flow at 700 mb across the region 
during the day Friday. For now played up probability of precipitation a bit more across the 
area for Friday with low/middle scattered pop values. 


A bit of difference between the two simulations continues into Friday 
evening into Sat. GFS showing the trough lagging behind while the ec 
much more progressive. For now kept low probability of precipitation across area during 
these time periods. 


As for temperatures...it will be noticeably cooler on Friday as compared to 
the rest of the week. Expect temperatures in the 40s to around 50 over the 
plains on Friday. 


Sunday should be quite nice with sunny skies returning and temperatures 
returning into the l60s. \/34 


Aviation... 


Expect VFR conditions at kals through tomorrow. 


Expect MVFR conditions at kcos and kpub this morning. Light rain 
has been falling off an on along with some patchy fog at kpub early 
this morning with reduced visible and ceilings. Expect this trend to 
continue through 12z this morning with VFR conditions expected by 
20z. 


Low ceilings are producing MVFR conditions this morning at kcos 
and will continue through 19z this morning. A brief snow shower may 
pass across kcos early this morning with little impact. VFR 
conditions can be expected at both kcos and kpub this afternoon and 
overnight. 88 


&& 


Pub watches/warnings/advisories... 
none. 
&& 


$$ 


51/27 

National Weather Service Glossary of Abbreviations

Non-Expanded Version (with abbreviations)