Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Denver/Boulder Colorado
248 PM MDT Tuesday Jul 26 2016

Short term...(this evening through wednesday)
issued at 219 PM MDT Tue Jul 26 2016

An upper level high over the Great Basin will produce a northwest
flow aloft over Colorado. Convergence along a surface trough over
eastern plains is expected to trigger thunderstorms this afternoon
and early evening. With cape running 1000 to 3000 j/kg a severe
storm or two will be possible over the eastern plains even though
wind shear isn't that great.

A cold front will drop south across eastern Colorado late tonight
and Wednesday morning. Northeast to easterly winds behind the front
will increase low level moisture Wednesday. If dew points hang in
the 50s through the afternoon surface based cape will reach 1000 to
2000 j/kg along the Front Range and eastern plains. A cap at 700mb
will limit convection development. Where convection is able to
break through the cap, severe storms will be possible with large
hail, damaging winds, and heavy rain. Highs behind the front look
to be in the upper 80s to around 90 across northeast Colorado.

Long term...(wednesday night through tuesday)
issued at 219 PM MDT Tue Jul 26 2016

Upper high remains centered over the southern Great Basin through the
end of the work week...with a northwest flow aloft over Colorado.
This pattern should allow upper level disturbances and associated
cool fronts to move across northeastern Colorado. In
addition...models show 40-50kt jet Max across the far northeastern
corner of Colorado. This pattern should bring near normal
temperatures to north central and northeastern Colorado for
Thursday and Friday...with isolated to scattered showers and
storms possible...most numerous east of the mountains. A few of
the storms could be strong with hail...gusty winds and heavy rain
over the plains...most likely to the east of Denver where more low
level moisture and lift is available. Difficult to know which day
would produce more convection due to differences between where
the GFS and NAM models place the surface boundaries.

Warmer and drier weather is expected on Saturday as the upper high
elongates and builds over the Rocky Mountain region. There should be
enough moisture around combined with daytime heating to produce a
few mainly high based storms over higher elevations.

By Sunday...models show the upper high shifting eastward into the
Southern Plains states which could allow monsoonal moisture to move
into Colorado from the south. As a result...the mountains could see
a better chance for afternoon and evening showers and storms on
Sunday...with a better chance across all of the County Warning Area by early next
week.

Temperatures will be near normal Thursday and Friday...with above
normal temperatures expected from the weekend into early next
week.



&&

Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 219 PM MDT Tue Jul 26 2016

There will be a slight chance for thunderstorms at the Denver
airports through 02z. Gusty outflow winds to 40 knots and brief
heavy rain will be the main threats from the storms. Outflow winds
from the thunderstorms may produce a wind shift or two through
02z. Winds will settle a south to southwest direction this evening
and continue most of the night. A cold front will push through
northeast Colorado around 12z bringing north to northeast winds.
There will be a slight chance for low clouds with the best chance
being kfnl to kgxy and north. There will be a slightly better
chance for thunderstorms late Wednesday afternoon and evening.

&&

Bou watches/warnings/advisories...
none.
&&

$$

Short term...meier
long term...Kalina
aviation...meier

National Weather Service Glossary of Abbreviations