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Area forecast discussion 
National Weather Service Grand Junction Colorado
300 PM MDT Tuesday Sep 23 2014

Short term...(tonight through Wednesday night)
issued at 300 PM MDT Tuesday Sep 23 2014

Upper ridge building over our County Warning Area through the period as upper
trough off the West Coast deepens...with resultant drier air and
warming trend. Our County Warning Area will remain east of the ridge axis tonight
with northwest flow aloft continuing to keep a little middle level moisture
across portions of our County Warning Area...mainly northwest Colorado. Still a threat for a
few sprinkles in the mountains around Steamboat Springs through
early this evening due to combination of weak convection and
orographic lift. Otherwise...lingering precipitation is about
done for this time period in our County Warning Area.

Mostly sunny Wednesday...though expect a few clouds developing
over mountains in the afternoon due to daytime heating. But
threat of any precipitation is very minimal due to subsidence. Maximum
temperatures Wednesday should generally be 4 to 6 degrees f higher
than today as 700 mb temperatures rise 2-4 degrees c across our County Warning Area.

Long term...(thursday through tuesday)
issued at 300 PM MDT Tuesday Sep 23 2014

Thursday...under the positively tilted ridge...there will be a
weak return flow of moisture from the southeast into the Pagosa Springs-
Lake City area. This backdoor moisture will be deeper in New
Mexico and will percolate northward more on Friday for isolated to
scattered showers and storms over the southern zones and along the
Continental Divide. Otherwise daytime temperatures will be 4-8
degrees above normal and winds will generally be terrain and
thunderstorm driven. Some gusty outflow winds are possible for
the southern half of the forecast area but are hard to resolve for

Friday night the ridge axis gets squirted NE as the eastern
Pacific trough closes over Oregon-California. The GFS timing has
slowed to better match the ec. Subtropical moisture begins to
surge into the Great Basin then works through Utah Saturday and
Saturday night. The GFS is pulling precipitable water values over
one inch into the region increasing the chances of heavy rainfall
especially on Sunday when the best upper divergence is currently
timed to work over the region.

Monday-Tuesday moisture erodes with the passing trough though
isolated to scattered storms are possible mainly over the northern
zones. The Pacific remains active and reloads quickly for a
another trough passage currently timed for mid-week.


Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 300 PM MDT Tuesday Sep 23 2014

VFR conditions are expected today through Thursday. Isolated
circumnavigable afternoon thunderstorms will collapse before
sunset. Kvel may be impacted by gusty erratic outflow winds
through 02z. No impact is expected at other regional taf sites.


Gjt watches/warnings/advisories...


Short term...jrp
long term...Joe

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