Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/06/19

Area Forecast Discussion

National Weather Service Denver/Boulder CO

 Issued by National Weather Service Pueblo CO
836 PM MDT Thu Sep 5 2019

.UPDATE...
Issued at 836 PM MDT Thu Sep 5 2019

Persistent storm continue to form along an outflow boundary over
the plains and over the metro area. Increased PoPs for the next
few hours, but eventually a stable atmosphere will overcome the
showers that are occurring.

&&

.SHORT TERM...(This evening through Friday)
Issued at 344 PM MDT Thu Sep 5 2019

Satellite and radar pictures are showing some convection
developing over the mountains, foothills and the plains in Weld
county at this time. The strongest convection is over northern
Park County. The plains have a northeasterly wind field in place
at this time. It is difficult to locate a cold front over the
plains or upstream in Nebraska or Wyoming. Most locations have
north and northeasterly winds now. There is still a significant
cap at around 450 mb on the ACARS soundings at this time. Models
keep the upper ridge centered over southern Colorado overnight.
The upper ridge center migrates south into New Mexico by Friday
afternoon. The flow aloft is weak and west-southwesterly tonight
and Friday. The QG Omega fields have very weak upward energy in
the synoptic scale for the CWA tonight and Friday. The low level
wind fields show easterly upslope winds much of tonight, then
east-southeasterlies much of Friday. For moisture, there is plenty
in the mid and upper levels on all the models tonight and Friday.
Precipitable water values are in the 0.75 to 1.10 inch range this
evening, then they increase into the 0.75 to 1.50 inch range
overnight and Friday for all the CWA. There is fairly high CAPE
over the mountains this evening. Values are pretty high again over
the western half of the CWA Friday, with some CAPE over the
eastern half. The QPF fields show measurable rainfall over the
high country this evening. On Friday, there is measurable
rainfall over much of the CWA with the highest amounts over the
mountains and foothills east of the divide. For pops, will go with
10-40%s this evening for the western half of the CWA. By Friday
afternoon, pops will be 30-80%s for the mountains, foothills and
western half of the plains.

.LONG TERM...(Friday night through Thursday)
Issued at 249 PM MDT Thu Sep 5 2019

The main features in the coming week`s weather are a weak
shortwave moving over the northern Rockies as there`s a moisture
plume over Colorado on Saturday, followed by a larger shortwave
trough late Sunday. The models are in pretty good agreement on
these features. The only complicating issue is that the amount of
instability on the plains is in question. Cool surface
temperatures will take the edge off of the thunderstorm threat
despite the moisture. This will likely limit how many storms get
onto the plains on Saturday. The Sunday wave should have better
lift to overcome weak capping and should also wipe out our
persistent inversion just above 500 mb, so Sunday afternoon looks
like the most likely time to get fairly widespread rain. It is a
fairly quick moving system timed in the afternoon, so one good
batch of convection with perhaps some weak trailing showers is the
most likely mode of convection, but it could be different if the
shortwave timing winds up being off a bit. Cloud cover will
restrain temperatures a little these days, likely keeping us in
the 80s despite a still hot air mass.

Behind the late Sunday trough, much drier southwest flow aloft
will develop. There could still be some limited late day
convection, mainly over the east slopes of the mountains. There
doesn`t appear to be a lot of warming, but we could creep up
towards the 90 degree mark again. Another trough should develop
over the west and could bring a bit stronger cooling and a better
chance of rain about Thursday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 836 PM MDT Thu Sep 5 2019

Showers are lasting longer than anticipated, therefore a tempo
group has been reintroduced into the TAF. Low clouds are
anticipated for KDEN, KAPA, and KBJC, but the coverage shouldn`t
be wide enough to lower flight categories, therefore VFR
conditions are anticipated throughout the forecast period.
Tomorrow afternoon and evening there is another chance at
thunderstorm development over all of the forecast points,
therefore gusty and erratic winds if a storm develops near the
forecast point.

&&

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

$$

UPDATE...PUB Backup
SHORT TERM...RJK
LONG TERM...Gimmestad
AVIATION...PUB Backup