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Area forecast discussion 
National Weather Service Denver/Boulder Colorado
317 PM MDT Sat Jul 12 2014

Short term...(this evening through sunday)
issued at 148 PM MDT Sat Jul 12 2014

Airmass is very moist with precipitable water values greater than an
inch and dew points in the middle 50s to lower 60s. Convective available potential energy are roughly
700 to 1300 j/kg. Thunderstorms will continue to build over the
mountains and foothills and spread east onto the plains this
afternoon and evening. The threat for heavy rain with possibility of
flash flooding will continue into the evening. Current storms are
not moving much over Northeast Park and El Paso counties. Will
continue with Flash Flood Watch through middle evening. The storms over
Larimer County are moving east around 15 to 20 miles per hour. This and drier
air moving in this evening will keep the flash flood threat low.
Chance for showers and storms will end from the north first as drier
air moves in from the northeast at the middle levels. Still could see a
few lingering showers late tonight...mainly south and east.

Northwest flow aloft will increase as upper level ridge intensifies
over the Great Basin. Precipitable water values fall to around an
inch...which is still somewhat moist. A weak disturbance embedded in
the flow aloft will trigger scattered storms Sunday afternoon. Due
to drier air and stronger flow aloft...the threat for heavy rain and
flash flooding will be lower. Shear will increase...however convective available potential energy
will be low...less than a 1000 j/ the severe threat will be
low too. The northwest flow will keep cooler air over the area.

Long term...(sunday night through saturday)
issued at 148 PM MDT Sat Jul 12 2014

Models have moderately strong northwesterly flow aloft over the
forecast area Sunday night through Tuesday night. Basically...the
models have a significant upper trough/closed low over the Great
Lakes with the upper ridge center of over the Great Basin all five
periods. The qg vertical velocity fields have weak upward motion
for the County Warning Area most of the time. For the most part...the boundary
layer flow has an easterly component to it from The Divide
eastward all five periods. For moisture...there is plenty the
whole time. Precipitable water values are prognosticated from 0.8 to 1.2
inches for the plains and foothills Sunday night through Tuesday
night. The low level dew point proggs have 50 to lower 60s f
readings for the plains and foothills all five periods. The cape
is fair Sunday evening...the highest values are over the
foothills. For late day Monday...there is cape over the western
two-thirds of the County Warning in the mountains...with practically
nothing over the northeast corner. On late day Tuesday...there is
significant cape over the western half of the plains...some areas
with over 2000 j/kg. The quantitative precipitation forecast fields show some measurable rainfall
across all the County Warning Area the day day periods. The best amounts are
Sunday evening and Tuesday late day. Will stay the course and go
with "chances" for the late day periods. Monday's high
temperatures are close to sunday's...maybe a tad cooler. Tuesday's
highs are similar as well. For the later days...Wednesday through
Saturday...models keep the upper ridge west of Colorado into
Friday...then it migrates eastward to be south of Colorado by
Saturday. Moisture is pretty good through Thursday then things dry


Aviation...(for the tafs through 00z Sunday late afternoon)
issued at 148 PM MDT Sat Jul 12 2014

Thunderstorms will again impact the Denver airports today through
02z. Heavy rain...small hail and strong winds will be possible with
the storms. Northeast winds may shift directions through 02z due to
outflow winds from convection. Once the storms move off to the
southeast...northerly winds are expected for the evening and
overnight hours.

There will be a chance for fog and low clouds again Sunday morning
09z to 16z. Have added a few low clouds to the tafs. Scattered
showers and thunderstorms are expected at the Denver airports Sunday


issued at 148 PM MDT Sat Jul 12 2014

Airmass will be very moist through this evening. There is a threat
for flash chance being from Denver south due to
slower storm movement and high number of storms. Flood prone areas
like burn/flood areas even outside of the Flash Flood Watch will see
a chance of flooding today. The heaviest rainfall rates will be
around one inch in 20 minutes.

There will be showers and thunderstorms again on Sunday...though
fewer than today. The flash flood threat will be lower Sunday due to
stronger flow aloft pushing storms along and a drier airmass.


Bou watches/warnings/advisories...
Flash Flood Watch until 9 PM MDT this evening for coz036-039>041.



Short term...meier
long term...rjk

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