Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 180957
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
357 AM MDT Sun Jun 18 2017

.SHORT TERM...(Today and tonight)
Issued at 325 AM MDT Sun Jun 18 2017

Some lingering showers over southern Washington County finally
dissipating. In its wake, a dry and subsident northwesterly flow
aloft will be over the region. Overall the airmass will be dry
and stable. Across the northeast plains, a weak anticyclonic flow
with weak east to southeast winds this aftn. There is a shallow
cloud deck, 040-060 kft agl along the Front Range early this
morning. The models show this mixing out by 15z with mostly sunny
conditions the rest of the day. No thunderstorms expected. Only
chance, albeit remote, will be over Park County but not enough to
warrant its inclusion in the grids. Coolest day of the week will
be today.

.LONG TERM...(Monday through Saturday)
Issued at 328 AM MDT Sun Jun 18 2017

The center of a hot dome of high pres over the Great Basin/Desert
Southwest region on Monday is projected to slowly migrate south-
southeastward over southern sections of Arizona and New Mexico and
northern Mexico by mid-week. In doing so, the northwest mid-level
flow over Colorado will gradually become nearly zonal and persist
through Friday. Before this occurs, the northwest flow aloft
appears to drive a weak cold front across nern Colorado Monday
morning. A relatively moist east-northeast low-level flow behind
this frontal boundary is expected to hold max temps to the low/mid
80s on the plains, and possibly produce a few gusty, weakly
organized t-storms over and near the high terrain circling South
Park. West slope areas will feel no effect from this frontal
system and therefore remain dry with temperatures creeping up into
lower 80s on the valley floors.

As geopotential heights rise with the upper ridge passing to our
south-southwest, temps will continue to climb and by Wednesday and
Thursday max temps on the plains are expected to be as much as 10-14
deg f above average for the date. How appropriate for the summer
solstice. FYI, average high at Denver for the 21st and 22nd is 84
and 85, respectively. Could see the strong heating sparking isolated
gusty t-storms late each afternoon and evening over and near the
Front Range. The high country won`t escape the heat with max
temps predicted to be in the 70s and 80s both days.

For Friday and Saturday, the GFS and ECMWF show the hot upper ridge
over the Southwest continuing its southward migration, helped along
by the southward shift of the jet stream along the bottom of an
upper trough dipping down over the northern Rockies. As a result
should see a slightly better chance for afternoon/evening showers/t-
storms for both days for the mtns and plains. Should also see a
return to near average temperatures.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 328 AM MDT Sun Jun 18 2017

ILS restrictions will be short lived this morning, with cloud deck
around 050 ft agl expected to dissipate after 15z then VFR
expected. Light east to southeast winds expected through this
aftn, generally less than 10 kts, than drainage winds overnight.
No tstms as the ams will be quite stable through this evening.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...Cooper
LONG TERM...Baker
AVIATION...Cooper



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