Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Denver/Boulder Colorado
952 am MST Thursday Nov 27 2014

issued at 952 am MST Thursday Nov 27 2014

Mild and dry day will prevail under a west-northwest flow aloft.
Temperatures have climbed in the upper 50s where the wind is
blowing near the foothills. In lower locations across the
northeast plains temperatures are in the upper 20s and 30s. May
need to lower temperatures in a few areas that have been slow to
warm. Appears the waves clouds will this should hold
temperatures some too.

Still looks windy in the mountains and higher foothills tonight
where gusts to 60 to 70 miles per hour will be possible.


Short term...(today through tonight )
issued at 315 am MST Thursday Nov 27 2014

The flow aloft will become more west-northwest as some higher level moisture is
embedded in the flow. There will be some wave clouds through the
day which may have some impact on high temperatures over northestern Colorado. With
downslope low level flow in place if skies were clear highs would
likely rise into the upper 60s to lower 70s along the Front Range
however with lower sun angle high cloud deck can alter temperatures quite a
bit in some cases. For now will keep readings in the middle 60s along
the Front Range with upper 50s to lower 60s near the Wyoming-NE border.
Meanwhile gusty winds will continue in the higher foothills and mountain
areas with gusts up to 60 miles per hour at times.

For tonight there is some potential for high winds in the higher
foothills and mountain areas after midnight as Cross Mountain flow increases
to 60-65 kts. Mountain wave is not well defined based on current data so
not sure how if they will stay above timberline or will mix down to
the the higher foothills.

Long term...(friday through wednesday)
issued at 315 am MST Thursday Nov 27 2014

Models have flat upper ridging over the County Warning Area Friday into Saturday
..then just zonal flow aloft. Anyway...jet level winds are
prognosticated in the 75-100 knot range from the west Friday through
Saturday night. The qg vertical velocity fields have benign
synoptic scale energy for the County Warning Area until Saturday...when upward
motion is prognosticated continuing Saturday night. The boundary layer
winds are downsloping west or southwesterly over all the County Warning Area for
all four periods. There is a bit of mountain wave set on the
cross sections for the foothills and mountains Friday and
Saturday night...but not highlight worthy. Moisture is very sparse
all four periods. There is a slight increase Saturday night...but
not very substantial. Doubt there will be enough moisture for a
decent wave cloud. None of the models show any measurable
precipitation for the County Warning Area Friday through Saturday night. No probability of precipitation
through Saturday night. For temperatures...friday's highs are
1.5-3.0 c warmer than today's expected highs. Saturday's are a
tad...0-1.5 c...cooler than friday's. Both day's MOS guidance
numbers from the NAM/GFS/ECMWF all show record or near record
highs for Denver. Readings will be 20-25 degrees f above normal.
For the later days...Sunday through Wednesday...models have a weak
upper trough pushing eastward to our north on Sunday. It brings in
a cold front and some upslope for the plains but moisture is still
insignificant. There is zonal flow on Monday. For Tuesday...the
European model (ecmwf) has a weak upper trough... the GFS is zonal moving to
ridging by Tuesday afternoon into Wednesday. There is more weak
upper troughing on the European model (ecmwf) for Wednesday. As a
result...temperatures vary quite a bit between the models. The
European model (ecmwf) has a bit of measurable quantitative precipitation forecast Sunday night late through
Tuesday but mainly in the mountains. The GFS has none through that
time. The GFS brings a tiny bit into the mountains on
Wednesday...the European model (ecmwf) is dry. Not good agreement...but the current
pattern looked wildly different between the two models 5 to 7 days
ago too. The GFS won that battle. May go with some minor alpine
probability of precipitation some of the time...but nothing significant. For temperatures
will mostly split the difference.


Aviation...(for the tafs through 18z Friday morning)
issued at 952 am MST Thursday Nov 27 2014

Middle and high clouds will continue to stream across Colorado today
and tonight. Winds will generally be south to southwest the next
24 hours and less than 25 knots. However at kbjc...westerly wind
gusts to 40 knots will be possible at times as winds move off the


Bou watches/warnings/advisories...


short term...rpk
long term...rjk

National Weather Service Glossary of Abbreviations