Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Grand Junction Colorado
357 am MST Friday Mar 6 2015

Short term...(today through saturday)
issued at 357 am MST Friday Mar 6 2015

A familiar Rex block pattern has returned to the West Coast. The
high center is over northern California...and the low center is
off the northern Baja California coast. The controlling ridge strengthens
and amplifies inland slightly through Saturday. Locally this will
weaken our northwest gradient winds aloft and will continue our warming
trend. The Baja California low lifts into SW Arizona by Saturday but this appears
to have no effect on our sensible weather even in the four corner

Afternoon temperatures will generally climb about 5 degrees
each afternoon to around normal by Saturday. The valley inversions
will remain intact through the afternoons...limiting mixing. The
Gunnison basin may have a strengthening inversion so have undercut
the warming trend there. Mostly clear skies and light winds
tonight will keep overnight lows below normal.

Long term...(saturday night through thursday)
issued at 357 am MST Friday Mar 6 2015

Beginning Saturday night the Rex block over the western U.S. And
eastern Pacific will continue breaking down. The Baja California closed low
will lift NE through Arizona and nm. The latest model runs show it
will move in phase with a weak cold front dropping down the Front
Range through Sunday afternoon. This front backs up against the
Front Range and slips as far west as the Continental Divide. The
GFS places an area of light precipitation over the easternmost San
Juan Mountains Sunday and Sunday evening. The European model (ecmwf) shows the same
trend but the area of precipitation is much smaller. The cold front will
remain draped north to south along the Front Range with some
moisture continuing to spill in the SW portion of the County Warning Area through

For Tuesday through Thursday the model solutions are changing.
Both the European model (ecmwf) and GFS are slowing down by 24 hours the final
breakdown of the West Coast ridge. Both the European model (ecmwf) and the GFS
hold back any significant moisture through Thursday with a much
drier solution tonight than in previous nights at the end of the
extended period.


Aviation...(for the 12z tafs through 12z Saturday morning)
issued at 357 am MST Friday Mar 6 2015

VFR is expected area-wide into next week. High clouds will pass at
times...expected to be thickest over the north.


Gjt watches/warnings/advisories...


Short term...Joe
long term...cirrocumulus

National Weather Service Glossary of Abbreviations