Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Grand Junction Colorado
323 PM MDT Monday may 25 2015

Short term...(this evening through Tuesday night)
issued at 323 PM MDT Monday may 25 2015

Upper level low pressure centered over western Nebraska will continue
moving slowly northeast. Associated cyclonic flow aloft over our
region today will be replaced a weak transitional ridge tonight
and Tuesday. However...little if any drying of the atmosphere in
general will occur ahead of next synoptic scale trough moving over
the Great Basin Tuesday night. So given the available
moisture...weak instability...and diurnal heating will have
continued isolated to numerous showers and thunderstorms from late
morning through late evening...focused on the higher terrain.
Small hail and gust winds will occur with strongest storms. Snow
levels could be locally as low as 9kft tonight...but should
quickly rise above 10kft Tuesday. Minimal impacts from snow
expected with main accumulations remaining well above 10kft.

Long term...(wednesday through monday)
issued at 323 PM MDT Monday may 25 2015

Closed upper level circulation with the aforementioned upper
level trough will move to the northern Utah/Colorado border region by Thursday
night. Without a bonafide change in the atmosphere in the
preceding southwest flow aloft...will continue the diurnally
driven showers and thunderstorms through Thursday. Upper level
system weakens as it passes overhead Thursday night and
Friday...but will still provide ample shower activity until it
passes east late Friday. Moderating temperatures ahead of the next
trough will bring the likelihood of near normal temperatures Wednesday
and Thursday...followed by cooler temperatures Friday and Saturday. Intensity
of precipitation through the week does not appear overall very
high...but could be locally heavy under the strongest
thunderstorms. Snow levels should remain above 11kft so only
impacts of snow will be on highest peaks and above passes.

Long term models in good agreement with an upper level ridge
building over the southwest U.S. By Sunday and moving over our
region next Monday. Will show warming and drying trend toward the
end of the 7 day forecast. If this ridge materializes as
currently forecast it would bring the warmest temperatures of
this Spring to our region.


Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 1115 am MDT Monday may 25 2015

Scattered showers and thunderstorms will continue to impact the
region through 06z this evening. Ils breakpoints will be met or
exceeded at all terminal sites as showers and thunderstorms move
through. Expect locally heavy rain...small hail and gusty outflow
winds to 30 kts near the stronger storms. Conditions are expected
to improve after 06z this evening...although there is a 30 percent
chance for patchy valley fog and low ceilings between 06z and 14z.


Gjt watches/warnings/advisories...


Short term...Ben
long term...Ben

National Weather Service Glossary of Abbreviations