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Area forecast discussion 
National Weather Service Denver/Boulder Colorado
1109 am MDT Monday may 25 2015

Update...
issued at 1038 am MDT Monday may 25 2015

There is an area of light showers associated with the wrap around
of the upper low. The showers are falling over eastern Weld...
Morgan...western Logan and northern Washington counties.
Precipitable water values on the morning soundings are similar to
what they've been for the last few days. Will make a few minor
adjustments...mostly for the current shower activity location.
Probability of precipitation look okay.

&&

Short term...(today through tonight )
issued at 410 am MDT Monday may 25 2015

Water vapor imagery showing upper low over northeast Colorado and
this feature will continue to move into Nebraska by afternoon.
Wrap around moisture is resulting in scattered showers over far
northern Colorado bordering Wyoming and Nebraska. Expect this
trend to continue through much of the morning hours. There are
also some snow shower activity in the mountains with modest west-northwest
orographic flow.

For this afternoon despite weak subsidence behind the low there
will be enough residual moisture and instability for scattered
coverage of showers and thunderstorms...especially higher terrain
and across the far northeast in closer vicinity to the upper low.
Surface based convective available potential energy only up to 500j/kg so not expecting and severe
storms today. Should see storms dissipate rather quickly this
evening with lack of upper air support and expect better clearing
tonight as well.

Long term...(tuesday through sunday)
issued at 410 am MDT Monday may 25 2015

In for a roller coast of a ride this week. Starts out warmer and
drier on Tuesday after a wet and coolish Holiday weekend. Upper
ridge builds over the region from the Great Basin. But plenty of
moisture still around with a steady stream of moist Pacific air
across the region. Should still see isolated to scattered
showers/T-storms Tuesday afternoon and evening with the help of
strong solar heating. Though not as much coverage as the day before.
Temperatures also on the rise with warming aloft with the ridge passing
overhead. By Wednesday upper ridge shifts east of the state
according to models and flow aloft GOES southwesterly. Models show a wave
embedded in this flow passing over the forecast area during the
afternoon and Erly evening hours. Southerly low-level flow out ahead of
this shortwave will increase low-level moisture across the northestern
corner of the County Warning Area...favoring storm development out that way late.
Could see a supercell or two form along a northeast moving north-
south shear axis. Wave lifts out overnight taking some of this
moisture with it. On Thursday...flow aloft becomes more southerly as
the next in the series of upper troughs drops in over the Great
Basin. Models slowly swing the trough across Colorado Thursday and
Friday and with it comes plenty of moisture and cooler air.
Precipitation chances will likely rise on Thursday but its Friday when
models esply the GFS paint a wet and unsettled weather pattern
across the forecast area. Moist upslope flow east of the mountains Friday
into Friday night would potentially result in widespread low
clouds...light to moderate stratiform precipitation and chilly temperatures for
the plains and foothills. Based on the GFS...we may even see
hydrology issues. Trough is forecast to move out late on Saturday and
be well east of the state on Sunday. And with an upper ridge
moving in...should see a couple of days of dry conditions and
above average temperatures starting Sunday.

&&

Aviation...(for the tafs through 18z Tuesday morning)
issued at 1038 am MDT Monday may 25 2015

There should be northeasterlies at dia into the early evening.
Ceilings could get bkn040 with the showers and thunderstorms.
There should be no ceiling issues after 06z tonight. Drainage
winds should kick in after 05z tonight.

&&

Hydrology...
issued at 1038 am MDT Monday may 25 2015

Lower flash flood threat today as moisture levels are lower while
airmass is more stable. Scattered light showers over the northern
border this morning but amounts will be under a tenth of an inch.
Still expect scattered coverage of storms this afternoon and
evening but heavy long duration storms not expected.

Current flood warnings will continue along the Cache la poudre in
Weld County and South Platte rivers through Weld..Morgan and Logan
counties.

&&

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

$$

Update...rjk
short term...entrekin
long term...Baker
aviation...rjk
hydrology...entrekin

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