Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

454
FXUS65 KBOU 191800
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1200 PM MDT TUE JUL 19 2016

.UPDATE...
Issued at 1148 AM MDT Tue Jul 19 2016

Not much to change in the forecast at this time. Moist airmass
remains over the plains but very warm temperatures aloft will
limit instability again with CAPEs under 800 J/kg. Drier near the
mountains and south of Interstate 70. Over the mountains CAPEs are
low but it will be warm enough to break the cap. There is a little
shortwave with a solid band of convection now from Steamboat
Springs to Glenwood Springs to Ouray. Showers have diminished this
morning but new storms should be developing along this line
shortly. This should be the main event today, moving over Denver
in the mid afternoon hours and across the plains through early
evening. There will be other storms developing as well, mainly
over the mountains and in the northeast corner. Small threat of
stronger storms in the corner where there is a bit more moisture.
Main threat there is heavy rain with more water available, a bit
more CAPE, and a more linear wind profile that could lead to a bit
of training. All of this is fairly well covered. I will make minor
adjustments to POPs, slightly higher over the mountains and
northeast corner this afternoon into early evening.

&&

.SHORT TERM...(Today and tonight)
Issued at 204 AM MDT Tue Jul 19 2016

An upper level high will remain over the cntrl and srn plains with
a continued influx of subtropical moisture in sw flow aloft
affecting the area.  Showers and tstms will redevelop over the
higher terrain by late morning thru early aftn.  Additional activity
will develop across the front range by early to mid aftn and then
spread across portions of the plains fm late aftn into the evening
hours.  Precipitable water values will continue in the 1.1" to 1.2"
range across most of nern CO so the storms may produce heavy
rainfall in a few spots. Threat of svr storms looks low however
can`t rule out an isold marginal svr storm. As for highs readings
will remain in the 90s across nern CO. For tonight most activity
should end before midnight.

.LONG TERM...(Wednesday through Monday)
Issued at 204 AM MDT Tue Jul 19 2016

Upper high pressure centered over Oklahoma on Wednesday will
slowly begin to retreat back west through Thursday to decrease the
amount of subtropical moisture that is transported up and over the
state. However enough moisture will remain for diurnally driven
storms across the forecast area. Expect scattered to numerous
afternoon storms for the mountains, moving east over the plains
during the late afternoon and into the evening with some possibly
lasting past midnight near the eastern border. Precipitable water
values remain near an inch, though CAPE values will be decreasing
with readings of up to 500 J/kg over the plains and some slightly
higher readings over the mountains. Temperatures will remain above
normal with the upper high remains nearby.

On Friday, a shortwave trough will push over the Northern Rockies
to flatten the upper ridge and push a cold front into the state
late Friday night into early Saturday. This will cool temperatures
back to near normal values for this time of year. The front will
actually push in relatively drier air from the north...so not
looking for a large uptick in storm coverage or intensity at this
time. The plains actually look to become capped with the post
frontal airmass. High surface pressure should stay over the Great
Plains on Sunday to keep in the relatively cooler temperatures
but a possible upper shortwave may help give storms a better
chance to spread across the plains during the afternoon.

Models are portraying an upper trough to dig along the western
states Sunday into Monday for an increase in southwesterly flow.
This will bring slightly warmer temperatures and likely a
continuation of diurnally driven storms.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1148 AM MDT Tue Jul 19 2016

Light north winds have developed near the mountains, with a
boundary across the Denver area. Expect this to rotate with the
winds becoming northerly at KAPA around 20z. Scattered storms will
move off the mountains and through the Denver area between 21z and
00z. Wind gusts to 30 knots are the most likely effect. Brief
MVFR conditions in heavy rain also possible, but only in the storm
cores. Instrument approaches to KDEN may be needed for a couple of
hours. The showers should diminish between 00z and 02z with VFR
conditions overnight.

&&

.HYDROLOGY...
Issued at 255 AM MDT Tue Jul 19 2016

A few spots may see an inch or two of rain this aftn into the early
evening hours along the front range and across the plains. However
the threat of widespread heavy rain and flash flooding looks low
at this time.

&&

.BOU Watches/Warnings/Advisories...
None.
&&

$$

UPDATE...Gimmestad
SHORT TERM...RPK
LONG TERM...Kriederman
AVIATION...Gimmestad
HYDROLOGY...RPK



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.