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Area forecast discussion 
National Weather Service Pueblo Colorado
339 PM MDT Tuesday Sep 2 2014

Short term...(this evening through wednesday)
issued at 338 PM MDT Tuesday Sep 2 2014

..near record high temperatures Wednesday...

Generally dry westerly flow across Colorado this afternoon with very
weak upper disturbance embedded in the flow crossing southern
Colorado. Satellite loop reveals a patch of moderate cumulus associated
with the disturbance over the San Juan/La Garita Mountains spreading
eastward...but have yet to see any lightning strikes within this
area as of 21z. Most mesocale models develop some very weak
convection over the la garitas and northern sangres late this
afternoon into this evening...and will include some very low probability of precipitation
for the higher peaks...though most activity will be sprinkles at
best. Overnight...stratus may return to portions of the eastern
plains...though developing west-SW flow will likely keep low clouds
rather patchy and confined to areas near the crest of the Palmer
Divide around Limon.

On Wednesday...W-SW flow strengthens over most of southern
Colorado...with deep mixing developing all areas by midday. Forecast
700 mb temperatures of 16-18c suggest very warm maximum temperatures...with forecast
highs near record levels at Pueblo (fcst 98f...record 98f in
1947)...Colorado springs(fcst 90f...record 91f in 1960) and Alamosa
(fcst 86f...record 87f in 1960). Threat of convection looks limited
to far southeast corner of the plains across Baca County...where low
level moisture will be slowest to mix out...and will leave isolated
probability of precipitation in place for late afternoon.

Long term...(wednesday night through tuesday)
issued at 338 PM MDT Tuesday Sep 2 2014

.Wednesday night and Thursday...Cold front will move southward
over the eastern plains and eastern mountains during the day.
Current models have the front passing over the County Warning Area during the late
morning and into the afternoon. Maxt grid has the north to south
temperature gradient over our on the County Warning Area. In the evening...low
level jet impinging on the front could produce some
convection...and increased probability of precipitation Thursday evening over the
southeast plains. Convection will try to move to the northeast
during the evening. Otherwise approaching weak disturbance could
keep some isolated to scattered thunderstorms over and near the
mountains continuing into the evening.

Friday through Sunday...moist atmosphere will be over the region
during the weekend with precipitable waters over 1 Standard
deviation above the mean. Upslope flow will increase low level
moisture over the lower elevations while plume of middle and upper
level moisture moves in the from the southwest. Tropical system Norbert
could help enhance the amount of moisture in the middle and upper
level moisture plume. Main question is how much instability and
lift will be available to produce precipitation. Approaching weak
disturbance on Friday afternoon and evening should help enhance
the convection especially over the eastern plains where low level
jet will develop. Location of the front and instability of the
atmosphere will be main challenges. On Saturday...the region could
get brushed by another disturbance. Will have to watch both days
for the threat of locally heavy rain and flash flooding...
especially on the burn scars. By Sunday...some drying aloft will
occur...but suspect still enough low level moisture for afternoon
and evening convection.

Monday and Tuesday...Lee trough develops with drying in the
lower levels. Ec and latest GFS has a trough passing over the
region Tuesday. With continued downslope flow on the
plains...lower levels will be dry. Have only silent probability of precipitation for
Tuesday over the plains. --Pgw--


Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 338 PM MDT Tuesday Sep 2 2014

VFR conditions at all taf sites the next 24 hours. Isolated -tsra will
be possible across the mountains early this evening...but not likely
to impact the terminals. Stratus may return for portions of the
southeast plains after 06z...though lower clouds will likely stay
northeast of the kcos and kpub terminals. Gusty SW winds will
develop most areas Wednesday afternoon with deep mixing...with a few gusts
to 20-25 kts at taf sites after 18z.


Pub watches/warnings/advisories...


Short term...petersen
long term...pgw

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