Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/24/16
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
955 AM PDT SUN MAY 22 2016
.SYNOPSIS...
A weaker marine layer over the area will keep a partly cloudy
skies in place through Sunday. Low clouds and fog will be a
staple of the forecast for much of the work week next week as a
broad and persistent trough of low pressure remains centered over
the West Coast. Enough instability may move over the area early
next to bring afternoon showers and thunderstorms to the mountains
and patchy night through morning drizzle to the Southland.
&&
.SHORT TERM...(TDY-TUE)
Lots of sunshine this morning as a weak inversion prevented any
sort of solid marine lyr from developing overnight. Still plenty
of low lvl moisture around and we should see seom stratocu
developing through the day, especially inland with some afternoon
heating. Temperatures again below normal but mild.
Overnight tonight models again not showing much of an inversion
setting up south of pt conception. There is a weak coastal eddy
circulation developing and plenty of low lvl moisture, but without
that inversion it`s hard to see anything more than just random
clouds around. There`s a stronger inversion along the central
coast so better chance of a solid cloud deck developing there.
Similar day Monday with little change in temps/sky cover. Models
appear to have backed off the instability Monday afternoon as LI`s
are barely negative and CAPE is under 200 j/kg.
***From previous discussion***
The upper low sets up camp over the bay area Tuesday and dry sw
flow with lower than normal hgts sets up over Srn CA. The onshore
flow and the cyclonic turning aloft will keep up the night
through morning low cloud regime going as well as the blo normal
temps. There will be enough instability over the mtns for some
afternoon cu but there will not be enough moisture for showers or
tstms to develop.
.LONG TERM...(WED-SAT)
On Wednesday the upper low moves into the northern section of the
forecast area. The now relentless night through morning low
clouds and fog patter along with blo normal max temps will
continue. In addition the cool air pool aloft assoc with the upper
low will produce enough mountain instability for a slight chc of
showers or tstms.
Dry nw flow sets up for Thu and Fri. Still plenty of onshore flow
to keep the night through morning low cloud pattern going...but
the slightly higher hgts will smoosh the marine layer down enough
to keep it out of portions of the vlys. Max temps will rise a
little but will still be slightly blo normal.
Another upper low is on track to move into the state on Saturday.
If this comes true there will be more low clouds and lower max
temps.
&&
.AVIATION...22/1635Z...
At 1630Z, there was no marine inversion at KLAX.
Overall, moderate confidence in 18Z TAF package. High confidence
in VFR conditions continuing for all sites through this evening.
Overnight, a significant inversion is not anticipated to develop.
So, low cloud formation will be random for coastal and valley TAF
sites. Therefore, relatively low confidence in coastal/valley
forecasts tonight/Monday morning.
KLAX...moderate confidence in 18z TAF. There is a 15% chance of
a brief period of MVFR cigs 18Z-00Z. For tonight, only moderate
confidence in return of MVFR cigs to the airfield (50% chance that
skies will remain clear).
KBUR...High confidence in 18Z TAF. There is a 20% chance of a
brief period of MVFR cigs 18Z-00Z. For tonight, moderate
confidence in VFR forecast (30% chance of MVFR cigs 10Z-17Z).
&&
.MARINE...22/830 AM...
For the Outer Waters, good confidence in current forecast. High
confidence in SCA level winds continuing across the southern two
thirds through this evening. For Monday and Tuesday, winds and
seas are expected to remain below SCA levels. However by Wednesday
and Thursday, winds will increase with a good chance of SCA
conditions developing.
For the Inner Waters, good confidence in current forecast.
Overall, winds and seas are expected to remain below SCA levels
through Wednesday. However, there will likely be some local gusts
to 25 knots in the afternoon and evening hours across the waters
north of Point Sal and across western sections of the southern
Inner Waters.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Monday For
zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...MW
AVIATION...RAT
MARINE...RAT
SYNOPSIS...30
weather.gov/losangeles
Area Forecast Discussion
National Weather Service San Francisco Bay Area
914 AM PDT SUN MAY 22 2016
.SYNOPSIS...An upper level trough over Northern California will
bring continued cooling to the area through the weekend. Another
upper level disturbance could bring a few showers to extreme
North Bay on Monday and Tuesday.
&&
.DISCUSSION...as of 9:15 AM PDT Sunday...Mix of clouds and sun
across our CWA this morning after areas of drizzle and sprinkles
overnight. Lots of reports of light accumulations. Cooler than
normal day expected with a northwesterly flow aloft due to a
system centered near Idaho/Western Montana. Highs will mostly be
in the 60s even in far-inland locations that are often over 80
this time of year. Precipitation is expected to be well to our
north, although HRRR and NAM do hint at a few minor showers this
afternoon over the hills. Will do an update to the grids to put in
a mention of rain for those spots.
Interesting to note that the longer range guidance has us in a
general trof pattern with no indication of a ridge of high
pressure building back to the coast at least the next 8 days.
.Previous Discussion...Satellite imagery shows a few low clouds
have formed over portions of the district, mainly over portions of
the North and East Bay, as well as northern San Benito county.
Temperature trends are running similar to those from yesterday at
this time with readings in the upper 40s to mid 50s, with dew
points in the mid to upper 40s.
Today is expected to be generally a nice day with highs ranging
from the upper 50s to lower 60s at the coast, to the 70s inland.
on Monday, another upper low will approach the area giving another
chance of showers to extreme northern Sonoma and Napa counties by
the afternoon. This will be repeated again on Tuesday with a
slight chance of showers again for the far north North Bay areas.
After midweek, the upper trough will begin to shift eastward as
high pressure rebuilds over the Eastern Pacific. This will bring
in a bit of a warming trend that will persist through the
remainder of the forecast period, with dry conditions as well.
&&
.AVIATION...as of 5:00 AM PDT Sunday...Moist boundary layer will
result in patchy low clouds across the region this morning. VFR/MVFR
cigs expected across area terminals this morning with patchy
IFR/LIFR conditions at select terminals. Low clouds will scatter
out around 17z. Light onshore flow will prevail with an afternoon
seabreeze increasing winds across KSFO and KOAK to 15 to 20 kt
with gusts to 25 kt this afternoon.
Vicinity of KSFO...VFR/MVFR cigs will prevail til 17Z this morning.
Light onshore flow will prevail with an afternoon seabreeze
increasing winds across KSFO and KOAK to 15 to 20 kt with gusts to
25 kt this afternoon as the onshore gradient from SFO-SAC
increases to approx 3 mb.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR/MVFR cigs will prevail til 17Z this
morning. Generally light onshore winds through forecast period.
&&
.MARINE...as of 9:15 AM PDT Sunday...A weakening upper low is
over the region. Expect light NW winds over generally light seas
through early this week. Stronger NW winds will likely return by
Wednesday and Thursday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...None.
$$
PUBLIC FORECAST: Bell/Sims
AVIATION: CW
MARINE: CW
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Area Forecast Discussion
National Weather Service Pueblo CO
602 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 338 PM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area until about 03Z...with little chance of storms tomorrow. The
most likely area for these showers or storms would be across the
central mountains, the Pikes Peak Region and the far eastern plains.
These storms do not look all that intense but would pose threats of
lightning and erratic wind gusts to 50 mph. Storms right near the
eastern Colorado border could be stronger. Storms may produce local
MVFR, IFR or even LIFR flight conditions requiring circumnavigation
by pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
[top]
Area Forecast Discussion
National Weather Service Denver/Boulder CO
305 PM MDT MON MAY 23 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM MDT Mon May 23 2016
A jet max that pushed into southwestern Colorado earlier today
continues to push northeast, firing off convection over the
forecast area this afternoon. A shortwave ridge will be pushing
overhead tonight, however convection will spread northeast for
the rest of the afternoon and evening as a theta-e ridge advects
into the area from the south. The chance of showers and
thunderstorms will mainly confine itself overnight over the far
northeastern corner of the state. Skies will be clearing overnight
with winds becoming light, but at this time am not expecting any
fog to form. Minimum temperatures will be right around average
for this time of year.
More thunderstorms are expected Tuesday as a fast moving shortwave
ejected from an upper trough over California pushes over the area.
At the same time, a surface low should push into central Colorado,
with southeasterly surface winds helping to advect in higher
theta-e values. CAPE values between 1000-3300 J/kg are progged,
with the highest values over the far northern to northeastern
plains. Shear and instability is enough to prompt SPC to cover the
northeastern plains with an Enhanced Risk of severe storms. Large
hail and strong damaging winds are likely from the stronger
storms, but cannot rule out a tornado forming with good turning in
the winds from the surface upwards. Temperatures will warm about 5
to 10 degrees over todays readings.
.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM MDT Mon May 23 2016
Models continue to indicate the passage of a couple of weak mid-
level instability axes/shortwave troughs over the forecast area
during the afternoon and evening hours Tuesday and Wednesday. The
stronger of these disturbances appears to pass over the area late
on Tuesday impacting mainly the northeast corner of the CWA
during the evening. Could see t-storms forming along a wind
shift/dry line which slowly translates northeast with the
shortwave during the evening. Best sfc based capes and instability
east of this boundary where gusty sely sfc winds continue to
advect in lower 60s wetbulb temps. A few storms may produce hail...
stg gusty winds and brief moderate to heavy rainfall rates. Cannot
rule out a severe storm east of a Briggsdale-to-Akron line. The
late Wednesday disturbance being carried along by strengthening
swly flow aloft appears weaker and not as moist. Yet may still see
isolated to widely scattered showers and t-storms produce gusty
winds and light to moderate rainfall over and along the Front
Range during the late afternoon and evening hours.
During the Thursday-Friday time period...the poorly organized long
wave upper trough over the Great Basin is still progged to migrate
eastward across the Rocky Mountain region during this period.
Models now in better agreement as they all show this open wave
trough bringing cooler air and a decent amount of moisture to the
state. Should see an increase in shower and t-storm coverage
both days. Thursday afternoon and evening appears to be the
optimum time for shower and t-storm development along and east of
the Front Range with the upper low passing to south and a moist post-
frontal low-level upslope flow on the plains. CAPES off interactive
soundings not terribly great due largely to cooler temps and
increasing cloud cover. However cannot rule out a couple of t-storms
producing locally heavy rainfall and hail. By Friday...models
show the CWA on the back side of the upper trough...but a weak
upr air disturbance swinging out of the nrn Colorado mtns and srn
Wyoming during the afternoon could generate additional showers and
perhaps a few t-storms. Although their intensity should not be
not as great as the day before. Temps Thursday and Friday expected
to drop 10 deg f or so from those on Wednesday.
Saturday through Monday...trough moves east and washes out over
the northern Great Basins placing the fcst area under a gentle
near zonal flow aloft on Saturday. Sunday and Monday the area
comes under the influence of a warmer south-southwesterly flow
with just a slight chance of heat driven afternoon and evening
t-storms each day.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 305 PM MDT Mon May 23 2016
VFR conditions are expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains.
Wind gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward light drainage
tonight. At this time, no widespread fog is expected, however
there could be some patchy areas along the South Platte River
valley. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Kriederman
LONG TERM...Baker
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Denver/Boulder CO
144 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 139 PM MDT Mon May 23 2016
VFR conditions expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains. Wind
gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward drainage
tonight. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Pueblo CO
1106 AM MDT MON MAY 23 2016
.SHORT TERM...(Today and tonight)
Issued at 342 AM MDT Mon May 23 2016
Shallow cold front was dropping southward through the plains this
morning, bringing a shift to north winds and slightly higher
dewpoints to most areas along and east of I-25. Front looks like it
will become stationary near the NM border by mid-morning, before
lifting slowly back northward through the afternoon and evening as
surface pressure begins to fall in response to next upper wave
dropping south along the west coast. Models suggest some modest low
level moisture and instability may pool along and north of the
boundary by late afternoon, with perhaps some isolated tsra
developing along the palmer divide and near the ks border as weak
moisture convergence may be enough to generate convection. 0-6km
shear will be sufficient for a strong to severe storms if convection
can develop, although best chances for severe will likely stay just
north and east of the area where deeper instability lies. Central
mountains could also see a brief tsra or two as well, though again
coverage/intensity will be sparse/weak. Max temps will continue to
drift downward a few degrees, with most noticeable cooling over
the eastern plains behind the front. Overnight, any convection
will end quickly in the evening as strongest forcing continues to
stay just north and east of the region. By early Tue morning, cold
front will slosh back southward through the plains, with perhaps
enough low level moisture for some stratus along the KS border
toward sunrise.
.LONG TERM...(Tuesday through Sunday)
Issued at 342 AM MDT Mon May 23 2016
...Best chance of rain on Thursday...
Extended portion of the forecast still looks pretty tame, and models
are in good agreement through the end of the week and into the
weekend.
Tuesday should be the warmest day of the period, with highs likely
topping out in the mid to upper 80s for the Plains...and 60s to low
70s for the higher elevations. Could be a bit breezy in the
afternoon as SW winds in the 30-35 kt range mix down to the surface.
Best chance for storms late in the afternoon will be mainly over NE
CO...so have maintained nil POPs for most of the area. Risk for
severe storms could sneak into Kiowa County by late afternoon or
early eve...so could see a slight risk of severe once again near
the KS border. SW flow pattern continues on Wed with continued
warm conditions and low threat of convection. Best chance for any
precip will be over the Pikes Pk region and Upper Arkansas Valley.
Thursday morning, the upper low to our west will finally start
moving into our area...reaching the 4 Corners area by mid day.
This will bring an increased threat of showers and storms...first to
the central and SW mountains early in the day...and then to the I-25
corridor and Plains by afternoon, as the upper low moves eastward
into KS by Thu evening. Upslope flow, especially on the backside of
the upper circulation, will put the best chance of precip over the
eastern mountains and southern Front Range. Could potentially see
some localized heavy rainfall from this system so will have to keep
an eye out for that. Severe potential looks low over the area with
generally low CAPE...but the latest NAM does bring a ribbon of
higher CAPE into extreme eastern CO in the afternoon, so will
have to see how much low-level moisture can make its way into the
Plains. Latest guidance pushes the trough eastward fairly quickly on
Friday, so should see fewer showers and storms on Friday but still
on the cool side of climatology for afternoon temps. The pattern
reloads for the weekend as quasi-zonal flow transitions to SW flow
ahead of the next trough developing over the PacNW. Rose
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1023 AM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area...primarily from 18Z to 03Z. The most likely area for these
showers or storms would be across the central mountains, the
Pikes Peak Region and the far eastern plains. These storms do not
look all that intense but would pose threats of lightning and
erratic wind gusts to 50 mph. Storms right near the eastern
Colorado border could be stronger. Storms may produce local MVFR,
IFR or even LIFR flight conditions requiring circumnavigation by
pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...LW
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1029 AM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 431 AM MDT Mon May 23 2016
VFR through tonight. Scattered thunderstorms are expected this
afternoon, with the main threat between 20z and 00z. Wind gusts to
40 knots and brief heavy rain are possible with the storms.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Pueblo CO
1112 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1111 PM MDT Sun May 22 2016
A cold front will drop south across KCOS and KPUB through 06z
tonight with a northerly wind shift. Expect VFR conditions at all
three terminals through the next 24 hours. A few showers and
thunderstorms will be possible on Monday afternoon over the Palmer
Divide, and should remain north of KCOS through the evening.
Southerly winds will be gusty at all three terminals Monday
afternoon into the evening. Mozley
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
AVIATION...MOZLEY
[top]
Area Forecast Discussion
National Weather Service Grand Junction CO
1051 PM MDT SUN MAY 22 2016
.SHORT TERM...(This evening through Monday night)
Issued at 400 PM MDT Sun May 22 2016
H5 hand analysis at 12z had a dominant ridge over the central
CONUS with low pressure systems along both right and left coastal
states. Our CWA is squeezed between the ridge and west coast low
leaving moderately fast southwest flow aloft. So far cloud cover
is keeping much of the winds at bay in the valleys...but at
ridge tops and near showers gusty winds will continue into the
evening. Expect showers to quickly die off after sunset with loss
of heating and under subsidence behind a passing wave. Downstream
blocking over the eastern states over the next 24 to 36 hours
leaves low pressure over the northern rockies and intermountain
west. This leaves southwest flow in place across the region with
little moisture advection. The 1.5 PVU progs suggest another wave
passing through Monday afternoon during peak heating and will lead
to another round of convection over the higher terrain over the
northern mountains. Temperatures will be slightly warmer on Monday
but stay below normal for this time of May.
.LONG TERM...(Tuesday through Sunday)
Issued at 400 PM MDT Sun May 22 2016
The downstream block will gradually break down by mid week and the
western trough will be allowed to traverse across the Rockies
Thursday. Wednesday will be a mirror of Tuesday with only isolated
afternoon convection anticipated in the afternoon. The passage of
the trough will bring an uptick to the convection Thursday which
will linger into Friday with cooler temperatures aloft aiding in
afternoon instability in northerly flow aloft. The next Pacific
system drops into the west Saturday and southerly flow return to
our CWA going into next weekend. At this time winds seem more of a
concern than precipitation. Temperatures remain below normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1043 PM MDT Sun May 22 2016
A weak cold front will continue to move slowly east out of the
forecast area tonight with winds diminishing overnight. Weaker
flow will return on Monday...however...breezy gusts are expected
at all TAF sites by the afternoon hours. Residual moisture and
instability will allow scattered afternoon showers and isolated
thunderstorms north of I-70 before diminishing by early evening.
This shower activity is not expected to impact airport operations.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...15
LONG TERM...15
AVIATION...MPM
Area Forecast Discussion
National Weather Service Pueblo CO
800 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 310 PM MDT Sun May 22 2016
Dry southwest flow will result in VFR over most of the flight area
for most of the forecast period. The far eastern plains, along the
eastern border, may see exception to this for a brief period late
this afternoon into the evening as storms fire along a dryline in
this vicinity. Pilots may have to navigate dryline storms in this
area...generally 22z-02z. KCOS...KPUB and KALS TAF sites should
remain VFR next 24 hours.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
Area Forecast Discussion
National Weather Service Denver/Boulder CO
756 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 748 PM MDT Sun May 22 2016
Sct high based showers and a few storms will move across the nern
plains thru midnight and then should end shortly thereafter as a
disturbance moves quickly across.
&&
.SHORT TERM...(This evening through Monday)
Issued at 345 PM MDT Sun May 22 2016
Have seen a few showers develop over Larimer County over the past
couple hours, with additional showers expected over the next few
hours. A short wave seems to be embedded in the prevailing
southwest flow which is producing the shower activity across
northwest Colorado and the northern mountains. The HRRR and RAP
models indicate that a band of shower activity related to this
short wave will develop on the plains after 02z. The I-25 corridor
should remain dry, but areast to the east of Fort Morgan should
see an hour or so of shower activity between 02z and 06z. Showers
will move out of the state by 06z with clearing skies overnight. A
weak surge of northerly winds across the plains will follow the
passage of the evening shower activity.
Additional cooling is expected tomorrow as weak northerly flow
continues. More thunderstorm activity is expected over the
mountains tomorrow afternoon as the state remains under southwest
flow aloft and an upper jet moves over the state, bringing a bit
more dynamic forcing than we have had the past couple days. Late
in the afternoon showers are then expected to spread out onto the
plains.
.LONG TERM...(Monday night through Sunday)
Issued at 345 PM MDT Sun May 22 2016
A cross CONUS blocking trough-ridge-trough pattern keeps a warm
and relatively dry swly flow over Colorado through mid-week.
Models show a couple of weak mid-level pertabations carried along
in this flow and passing over nern portions of the cwa Monday
evening and again Tuesday afternoon and early evening. Storms
forming on a wind shift line just east of the I-25 corridor is
forecast to shift northeast across weld...Adams and Morgan
counties Monday evening. Sfc based capes and instability may be
sufficient to support a few strong storms capable of small hail...
stg gusty winds and brief heavy rainfall. This storm area will
shift east-northeast with the shortwave passing through the nern
corner of the state during the mid to late evening hours. Models
indicate 3-hour qpf amounts in the 0-20-0.30 inch range out there.
The late Tuesday shortwave appears a bit weaker and farther
north with more of an impact on the northern Front Range and
northern I-25 corridor around Ft. Collins. Brief rainfall land
gusty winds probably main output from these high based cells.
Wednesday looks drier with strong mid-level subsidence..and temps
generally around average with a downslope flow off the Front
Range. Strong diabatic heating should still manage to generate a
few late day showers/t-storms over the high terrain.
Thursday-Friday time period...open wave upper trough passing over
the Great Basin is still progged to makes slow eastward progress
across Colorado during the period. GFS has come into closer
agreement with the European model which has changed little during
the past few runs. Both models as well as the DGEX and Canadian
models all show this trough and its cooler temperatures and
moisture enhancing shower/storm chances across the cwa. Best
chance for measurable precip appears to be late Thursday
afternoon/evening over and along the Front Range and Palmer
Divide...and on the northeast plains Friday afternoon with the
passage of a cold front. Would not rule out a few pockets of heavy
rainfall with rising precipitable water with this system.
By Saturday...models show this trough and front moving out across
the Great Plains and a shortwave upper ridge building over the
state...bring warmer and drier conditions to the area. This
trend continues Sunday with southerly flow and an amplifying
ridge.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 748 PM MDT Sun May 22 2016
An outflow bndry fm high based showers is moving south quickly
and should reach dia by 0215Z. Winds gusts to 30 mph fm the north
will occur for a brief period of time but should decrease by 03z.
A few high based showers/storms are developing behind the bndry
so may have to mention vcts at dia until 03z if they continue to
dvlp southward.
Overnight winds will become more ely by midnight and then sely
by 09z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...RPK
SHORT TERM...Dankers
LONG TERM...Baker
AVIATION...RPK
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
646 PM CDT MON MAY 23 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 315 PM CDT MON MAY 23 2016
20Z water vapor imagery continues to show a mean trough over the
western U.S. with southwest flow persisting over the central plains.
A MCV is seen in the water vapor and profiler data near the KS/MO
state line and continues to slowly drift east. At the surface, an
area of low pressure was analyzed over the OK panhandle with an
inverted trough of low pressure extending through eastern NEB. Low
level trajectories remain favorable for low level moisture advection
north.
For tonight, the main question is where will the next round of
convection develop and where will the resulting MCS and/or MCV
track. High resolution models vary from storms over central NEB to
southwest KS. Overall, think convergence along the inverted trough
axis to the northwest of the forecast area should be the main focus
for redevelopment as low level moisture continues to advect north.
However given the uncertainty of where storms may track overnight,
the forecast only has POPs at 50 percent for the overnight hours and
into Tuesday morning. I think it may play out similar to today where
storms to the west generate an MCV and that causes showers and
storms to fester over the area for a good portion of the day.
Although there is low confidence in the location of the showers and
storms. Deep layer shear is progged to be somewhat better tonight
and Tuesday. So there should be a little better potential for severe
storms. If the MCS is able to form a good cold pool, There could be
strong winds and hail with the storms overnight. Lows tonight should
again be in the lower to mid 60s due to cloud cover and the moist
airmass remaining over the region. Highs Tuesday of around 80
degrees are based on mixing the boundary layer to around 875MB with
some insolation. This may be overdone though if an area of clouds and
precip linger for a long time over any location.
.LONG TERM...(Tuesday Night through Monday)
Issued at 315 PM CDT MON MAY 23 2016
Thunderstorm chances will continue to be the main concern through
the extended forecast. Initial concern will be convective chances
Tuesday evening and Tuesday night. Depending on the duration of any
thunderstorms during the day Tuesday and any mesoscale boundary
could focus convection in the evening if convergence is strong
enough. Otherwise convection firing off of the dryline in western
Kansas may move into parts of north central Kansas overnight into
early Wednesday morning as the low level jet veers across northeast
Kansas. Models show capping inversion across the area through the
day on Wednesday and most of the day may remain dry after initial
morning convection ends. Dryline is forecast to remain to the west
of the forecast area in the afternoon. The models hint at a weak
wave moving northeast out of Colorado in the late afternoon and may
help initiate storms in northwest and parts of north central Kansas.
Shear is favorable across north central Kansas for supercells where
0-6km shear of 45 to 50 kts is forecast along with an unstable
airmass. Additional energy may move out across western and central
Kansas Wednesday night, this along with convergence across southern
Nebraska and northern Kansas around 850 mb may also cause showers
and thunderstorms to train along the border overnight Wednesday into
early Thursday morning. On Thursday and Thursday night a more potent
upper level trough will move northeast across western and central
Kansas and should fire storms along the dryline that is forecast to
be just west of our CWA. Again shear and instability coupled along
with good forcing for ascent will likely lead to severe storms
across parts of north central and northeast Kansas. The dryline and
frontal boundary looks to remain just to the west of the forecast
area through Saturday before retreating westward on Sunday. This
will act as a focus each day for storms as weaker waves move out of
the western trough and out into the Plains. Shear is weaker over the
weekend and into next Monday across central and eastern Kansas and
there may be a few stronger storms across the area. Temperatures
through the period will remain in the upper 70s to mid 80s with lows
mainly in the 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 646 PM CDT MON MAY 23 2016
VFR conditions should persist for the next several hours but
chances for limitations in clouds and/or precip seem to be
increasing for the 06Z-18Z window. Models showing some
consistency in cumulus field in west central Kansas developing
into convective cluster that moves east with time, aided by a
possible weak wave moving out of Colorado. Have gone ahead with
prevailing SHRA in most likely time of passage of this MCS.
Forecast soundings are also similar in rather moist lower levels
during this period bringing some potential for MVFR cigs in a
similar window.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...53
AVIATION...65
[top]
Area Forecast Discussion
National Weather Service Goodland KS
535 PM MDT MON MAY 23 2016
.SHORT TERM...(This afternoon through Tuesday)
Issued at 1158 AM MDT Mon May 23 2016
Cold front has stalled along the southeastern fringes of the
forecast area from Hill City to Gove. It may back up slightly this
afternoon and be the focus for isolated thunderstorm development
with the upper forcing still lagging over the central Rockies. If
a storm does develop...the environment will be conducive for
supercells with strong instability of up to 4000 j/kg and deep
layer shear of around 50kts. The aforementioned shortwave trough
will move out of northeast Colorado this evening and across the
northern tier of counties overnight. Point soundings show up to
2000 j/kg of elevated CAPE with little CIN in areas north of
Interstate 70 between 06z and 12z. High res model guidance shows
widespread qpf in that area. These slightly elevated thunderstorms
will be capable of producing large hail. In addition to the
thunderstorm threat...low level moisture will increase with light
southeasterly winds with areas of fog and low clouds likely
developing. Visibility could drop to less than a mile at times in
patchy dense fog which may linger through the mid morning hours.
The set up for Tuesday afternoon has strong to extreme
instability developing along and north of a Flagler to Tribune
line...most of the forecast area. Deep layer shear will be
slightly lower compared to today, around 40kts, but will be more
than sufficient for supercells. Problem as it has been the last
few days will be relatively weak upper forcing. Most likely
scenario will see isolated to widely scattered storms develop in
the mid to late afternoon hours in northeast Colorado as the next
shortwave emerges onto the plains and begins to move eastward into
the instability axis. Confidence is rather low due to the weak
synoptic scale forcing on the potential for anything more than an
isolated severe threat through Tuesday afternoon.
.LONG TERM...(Tuesday night through Monday)
Issued at 140 PM MDT Mon May 23 2016
Going into the extended period...the Tri State region will sit
between a broad h5 ridge over the eastern portion of the
country...with a digging slow moving upper trough building over the
rockies/western half of the country.
With this setup...Tuesday night on thru Wednesday will initially
have a few weak shortwaves move out over the plains region...moving
northeast along the western side of the blocking h5 ridge. Best
lift/dynamics ahead of these shortwaves will put best chances for
precipitation mainly north of Interstate 70...especially in sw
Nebraska.
By midweek...meandering surface boundary sets up in the Central
Plains out ahead of upper trough over the rockies. Models shift this
system eastward late Thursday and over the region thru Friday night
before lifting into north central Nebraska. Remnants of this
boundary do remain heading into the upcoming holiday weekend as
another upper low moves thru the north central rockies. For
precip...do expect an increase in areal coverage of rw/trw potential
as upper trough shifts eastward over the region...giving way to wrap-
around moisture going into the weekend. This moisture will be
enhanced by boundary remnants allowing for continuation of trw for
the weekend.
For temps...with a general sw upper flow over the region...looking
for near to above normal numbers thru the week as decent waa over
the area will only be hampered by extent of cloud cover/precip.
Overall...daytime highs will range from the mid 70s thru the mid
80s. coolest period will coincide with the passage of the midweek
upper trough. Overnight lows will range from the upper 40s thru the
mid 50s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 530 PM MDT Mon May 23 2016
For KGLD and KMCK...vfr conditions expected through approximately
09z or so with winds from the east and/or southeast 5-10kts. Could
see a thunderstorm or two near or over the terminals a bit later
this evening through the overnight but confidence not high enough
to include in the forecast. Updates will be sent when confidence
increases. After 09z or so stratus and ifr/vlifr cigs and possibly
visibility move in from the east-southeast and continue through at
least mid to late morning. During the mid to late afternoon hours
the stratus should slowly decrease from southwest to northeast
allowing vfr to mvfr cigs to develop with visibilities unlimited.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...024
LONG TERM...JN
AVIATION...99
[top]
Area Forecast Discussion
National Weather Service Dodge City KS
130 PM CDT MON MAY 23 2016
...UPDATE TO SHORT TERM...
.SHORT TERM...(This evening through Tuesday)
Issued at 130 PM CDT Mon May 23 2016
Dependent on the time frame for air mass recovery from yesterday`s
convection across the high plains southward into the panhandle of
Texas, thunderstorms will be possible across central and portions of
southwest Kansas tonight into Tuesday as short range models
indicate a difluent southwest flow aloft prevailing across the
Central Plains. The RAP13 and HRRR initialize well with the
surface low in extreme southwest Kansas and an attendant frontal
boundary extending northeast into north central Kansas and showing
both lifting northward across western Kansas through this evening.
A southeasterly upslope flow will redevelop across central and
much of southwest Kansas as a result, and in turn, draw moisture
back to the north raising surface dewpoints up into the lower and
mid 60s(F) across central and much of southwest Kansas. Heating of
the lower/mid levels will increase this afternoon as the
prevailing lower cloud deck continues to slowly scatter out,
allowing lower/mid level lapse rates to steepen. Depending on how
long this takes, thunderstorms will be possible toward early evening
as the cap weakens with the best chance for convection associated
with the frontal boundary as it lifts north. Short fuse model
soundings show SBCAPE values climbing in excess of 4000 J/KG
across south central and eastern southwest Kansas through early
this evening, increasing severe potential. Based on the
substantially high amount of CAPE, large hail will be the primary
threat with damaging winds also possible. Due to a modest amount
of vertical shear present, an isolated tornado threat closer to
the Oklahoma border does exist.
A few isolated storms may develop across eastern Colorado within
an upslope flow and move into west central Kansas later tonight
as an H5 vort maxima kicks northeast out of the Southern Rockies
into the Western High Plains. However, with less instability
available, the potential for severe storms will be limited with
damaging winds the main threat.
A prevailing low level south to southeasterly flow across western
Kansas tonight will help reinforce a moisture pool across the
area with surface dewpoints remaining in the upper 50s(F) to the
mid 60s(F). Look for lows generally in the 60s(F) toward daybreak
Tuesday with a few upper 50s(F) possible in west central Kansas.
For Tuesday, warm air advection across the high plains will push
H85 temperatures well up into the mid to upper 20s(C) across
southwest and much of central Kansas. Widespread 80s(F) can be
expected for highs Tuesday afternoon with near 90F possible in
extreme southwest Kansas. Similar high temperatures are likely
Wednesday and Thursday with little change to the general air mass
across the high plains.
.LONG TERM...(Tuesday through Sunday)
Issued at 352 AM CDT Mon May 23 2016
Little changes in the overall synoptic pattern in the coming days.
The models have been consistent will keeping Wednesday the likeliest
day to be dry and quite (no convection at least), however the rest
of the forecast looks fairly active with at least peak heating
dryline storms and waves exiting the the quasi-stationary western
upper trough. The warming trend will continue into mid week with
90s almost a certainty by wednesday. More clouds and precipitationmay
cool temperatures by late week with models showing a strong
shortwave into the plains. Overnight lows remain somewhat mild in
the mid to upper 50s through the period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1220 PM CDT Mon May 23 2016
VFR conditions will prevail at all TAF sites through late this
afternoon. Thunderstorms are then expected to develop and move
northeast across central and portions of southwest Kansas this
evening, potentially affecting KHYS with brief periods of MVFR/IFR
cigs/vsbys. There is less confidence of KDDC or even KGCK being
affected. Otherwise, VFR conditions are expected to continue
through early Tuesday morning. Winds will remain light and variable
through this evening as a near stalled out frontal boundary situated
across north central into southwest Kansas begins to lift slowly
north. East to southeast winds around 5 to 15kt are expected to
develop later this evening as the frontal boundary lifts further
north.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 81 63 87 64 / 30 30 20 20
GCK 81 58 87 60 / 20 20 10 10
EHA 84 58 90 57 / 10 10 10 10
LBL 84 62 90 62 / 20 20 10 10
HYS 78 62 84 63 / 30 40 20 20
P28 79 67 86 67 / 40 50 30 30
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...Russell
AVIATION...JJohnson
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
643 PM CDT MON MAY 23 2016
.UPDATE...
Issued at 643 PM CDT Mon May 23 2016
We expanded a low-end chance of showers and isolated thunderstorms
to the remainder of central ND with this update (and maintained the
mention in western ND) through mid-evening. As of 2330 UTC, steep
low- and mid-level lapse rates have allowed weak convection to
form as far east as the Rolla and Jamestown areas. The activity is
likely being aided by a weak shortwave trough entering southwest
ND per water vapor imagery. Model guidance, including recent RAP
and HRRR simulations, have been keying on a bit more well-defined
batch of convection ahead of that impulse, but those models could
be a bit too slow with its passage based on radar trends. Finally,
note that the dry boundary layer characterized by temperature-
dewpoint spreads of 40-50 F is contributing to gusty winds with
some of the showers and weak storms, and will continue to do so
until the boundary layer begins to decouple with the approach of
sunset.
UPDATE Issued at 420 PM CDT Mon May 23 2016
A quick update to add in an isolated rain shower central ND with
the shallow cumulus field and weak returns on radar. These should
begin to diminish this evening except in the southwest and south
central, where the next shortwave mentioned in the previous
discussion will maintain development through the evening and
overnight hours. Updates to the text products being sent out now.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 240 PM CDT Mon May 23 2016
Overall theme will be multiple shortwaves rotating around a
nearly stationary closed upper low in southern Saskatchewan,
resulting in periodic showers and thunderstorms. The best
probability will be Wednesday as the upper low melds into an open
wave as it merges with another stronger shortwave rotating in
from eastern South Dakota. A moist southwest flow remains in tact
through the long term period keeping an unsettled weather pattern
for western and central North Dakota.
Tonight through Tuesday, a weak shortwave in eastern Montana will
shift toward the ND/MT border near Williston this evening. Current
regional radar shows isolated showers in eastern Montana with weak
surface based convective available potential energy or CAPE.
Expect isolated to scattered showers and isolated thunderstorms
with this feature into western ND late this afternoon into early
evening. No severe weather anticipated with cape of 200-400 j/kg
along with low to mid level lapse rates between 7.5 and 8.5 c/km
and 0-6km shear around 15kt.
Another shortwave seen in northern Wyoming will shift into
northern South Dakota this evening, and then into the James River
Valley later tonight. A surface reflection with low pressure in
northern SD will move east along the border. Model data shows an
area of showers and perhaps an isolated thunderstorm developing in
southwest ND early this evening then moving into south central ND
between 10pm Monday and 2am Tuesday before reaching the James
River Valley by 12z Tuesday.
On Tuesday, once the aforementioned shortwave exits the James
River Valley during the morning, expect only a slight chance of
afternoon showers or thunderstorms associated with cyclonic flow
and daytime heating. Areal coverage will remain limited.
.LONG TERM...(Tuesday night through Monday)
Issued at 240 PM CDT Mon May 23 2016
The next shortwave trough mentioned in the short term period
rotating up from eastern South Dakota Tuesday night through
Wednesday will dumbbell and meld with the Saskatchewan upper
low. This will result in likely showers and thunderstorms during
the day Wednesday, then decreasing a bit Thursday.
For Friday through Monday, periodic shortwaves embedded within a
continued southwest flow will produce showers and thunderstorms
through the long term period. Timing of each wave difficult to
discern at this time. High temperatures will mostly be in the 70s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 643 PM CDT Mon May 23 2016
A few showers and thunderstorms will occur across western and
central ND this evening. Gusty winds to 40 kt and brief, local
MVFR conditions are possible with that activity, especially in
southwest and south central ND. We expect the showers and weak
storms to diminish after 06 UTC. VFR conditions will otherwise
prevail tonight and Tuesday.
&&
.BIS Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...KS
AVIATION...CJS
AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
1100 PM PDT MON MAY 23 2016
New Aviation Discussion
.SYNOPSIS...
A broad low pressure system will remain over the region into
midweek for breezy winds and below normal temperatures. A cool
weather pattern will prevail with a few showers at times. A high
pressure system should begin to build in on Thursday for normal
temperatures into the weekend.
&&
.UPDATE...
Locally gusty Sundowner winds have developed across Southern
Santa Barbara County this evening. With KSBA-KSMX gradients a tad
weaker than last night, winds are expected below advisory level
winds.
A broad trough remains over the West Coast this evening per the
latest water vapor imagery. A shortwave trough moving around the
broader trough circulation is currently located about 400 miles
west-northwest of Los Angeles. The shortwave trough and its
associated jet streak will wrap around the trough and nose into
the South Coast Basin after midnight tonight. With some clouds
developing on infrared satellite this evening ahead of the upper-
level feature and an eddy circulation remaining intact, mentions
of showers have been added to the forecast. The instability aloft
could interact with the expanding stratocumulus deck across the
South Coast Basin to bring mainly isolated showers to the coast,
valleys, and mountains.
Strong onshore flow in place and a bit better upper-level wind
support with the vorticity maximum could bring advisory level
winds to the Antelope Valley on Tuesday afternoon and evening.
The next shift will be briefed about the wind possibilities.
&&
.PREV DISCUSSION...
SHORT TERM...By late morning Tuesday with the added low lvl
moisture most areas should at least have more clouds with cooler
daytime highs. Again, a very small chance of a
sprinkle/drizzle/light shower around with the deep inversion. With
the daytime heating and lift from the onshore flow clouds should
increase over the mtns with some isolated light showers there.
Stability parameters were very poor in the models for tomorrow
(and Wednesday), possibly just due to too much cloud cover, but
didn`t feel like there was much chance of thunder so that`s been
removed.
A second upper low dumbbells around the trough and moves through
Wed morning. Here again no real organized features to really have
much confidence in. A little moisture mainly below 850 mb again
with the flow shifting to northwest behind the trough in the
afternoon. And again a very weak marine inversion making it a
tricky sky cover forecast. Overall partly cloudy, maybe some
periods of mostly cloudy, perhaps an isolated light
sprinkle/shower, mainly near the mtns.
Air mass starts to dry out Wednesday night as the trough finally
exits to the east and a very brief low amplitude ridge develops
over California. Should be a sunnier day Thu with little threat
of any precipitation. Perhaps some afternoon clouds over the mtns
with highs a few degrees warmer than Wed.
LONG TERM...The little warming trend will continue into Friday
before a weak trough returns for the weekend. Minimal impacts
locally other than a cooling trend through early next week with a
deepening marine lyr.
&&
.AVIATION...
24/0600Z
At 06Z AT KLAX there was no marine layer.
Low confidence in TAFs due to a weak marine layer. There is a 40
percent chc of no MVFR conds for all TAFs KSBA and south. There is a
better chance of low VFR BKN conds later this morning and afternoon.
KLAX...Low confidence in TAF. There is a 40 percent chc of no cigs
through 17Z. Better chc of VFR cigs after 17Z but could range
anywhere from 035 to 080.
KBUR...Low confidence in TAF. There is a 40 percent chc of no mvfr
cigs.
&&
.MARINE...
23/900 PM
Winds will diminish some between late tonight and Tuesday night.
There is a 30 percent chance that the Small Craft Advisory could
be extended through Tuesday evening. Widespread advisory level
winds are expected across the outer waters from Wednesday evening
through at least Friday.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday For
zones 650-673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Hall/MW
AVIATION...ASR
MARINE...Hall
SYNOPSIS...Seto/Hall
weather.gov/losangeles
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
911 PM PDT MON MAY 23 2016
.SYNOPSIS...
An upper level disturbance will continue to bring unsettled
weather and cool conditions across NorCal most of this week.
Warmer and mainly dry conditions by this weekend.
&&
.DISCUSSION...
Low pressure area is moving over the Northern San Joaquin Valley
this evening. Showers have been gradually dissipating this evening
over the interior. The HRRR model is indicating some showers
enhancing over Shasta County and moving over the north end of the
valley overnight while the NAM model is keeping the valley dry and
indicating just a few showers over the mountains.
That shortwave over the San Joaquin Valley on Tuesday will help to
continue unsettled weather for the region. Most of the activity
will be focused over the mountains but some showers or isolated
thunderstorms could end up over the valley once again. Isolated
thunderstorms will continue to be possible for the afternoon into
the early evening hours.
On Wednesday the low moves over Southern California. This will
keep unstable conditions over the region with most of the activity
continuing to be focused over the mountains and slight chances
over the northern half of the Sacramento valley. Temperatures will
continue to be cooler than normal but 3-5 degrees warmer than
Tuesday.
On Thursday the trough moves far enough to the east to dry out
most areas. Only some isolated afternoon showers over the
mountains near the crest look possible. Temperatures will warm
back up to near seasonal normals.
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
On Friday, Northern California will be on the relatively dry
backside of the upper level trough. The northernly flow should
bring dry conditions to nearly everyone although there could be
enough instability in the Sierra to set off some afternoon
thunderstorms. For both Friday and Saturday, winds could become a
bit breezy at times while temperatures should be right around
normal for this time of year. Beyond this, both the GFS and ECMWF
have a weak shortwave dropping down the backside of the trough
which may trigger more mountain thunderstorms Sunday and into
Monday.
&&
.AVIATION...
VFR conditions expected over the next 24 hours with relatively
light winds. The upper level trough continues to linger over
Northern California and will result in SCT 5-8 kft cumulus in the
valley in addition to a higher (20 kft) SCT to BKN deck. Lcl MVFR
conditions in the mountains. Most of the shower activity tonight
should remain in the higher elevations.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
342 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 337 AM MDT Tue May 24 2016
...Warm and generally dry today...
Currently...low clouds are slowly expanding over the NE portion of
the CWA, and will likely continue to expand over the next few hours.
Areas of stratus will be most likely east of I-25 and north of Hwy
50. Low cloud deck should dissipate by mid morning, leaving mostly
sunny skies for the rest of today.
Main concern today will be the potential for strong to severe storms
over a small portion of the CWA, generally from Eastern Pueblo
County eastward to the KS border, and north of Hgwy 50. A surface
low will depend to about 996 mb this afternoon, setting up over
Bent and Prowers counties late in the day. North of the surface low,
surface winds will back strongly in a moisture rich environment with
CAPE approaching 3000 J/kg. Along with bulk shear in the 40-50 kt
range, this environment will be conducive to supercell development.
The surface low will shift northward by late afternoon, leaving only
a short window of opportunity for storms to develop in our area. The
NAM keeps the area free of storms, while other high res solutions
such as the ARW and NMM develop a couple cells in this area late in
the afternoon. Given the potential, will introduce low POPs for this
period. The severe threat looks mainly confined to Kiowa County, but
could shift to include more or less of our CWA depending on the
surface low development. Since all modes of severe wx would be
possible with any storms that form, will have to watch for this
potential later this afternoon.
Otherwise, just a warm and breezy day, with temps in the mid to
upper 80s over the plains and south to southwest winds gusting in
the 20-30 kt range this afternoon. Dry SW flow will increase by
evening, leaving us with a clear night with seasonal temps in the
40s for the plains and 30s for the high valleys. Rose
.LONG TERM...(Wednesday through Monday)
Issued at 337 AM MDT Tue May 24 2016
Troughieness over the western conus will keep the pattern potentially
active over the region during this period. The most active day is
expected to be Thursday as strong to severe storms may occur.
Friday should be cool with quite a few showers/-tsra over the
region.
Wednesday...
Primary trough will still be just offshore of the Calif coast and
will be moving inland during this day. Mid lvl low over the region
will be southwesterly with a weak shortwave ridge moving over the
area. Expect mainly dry warm weather will only an isold tsra over
the higher trrn...and possibly a high based tsra over the palmer
dvd.
Thursday...
Trough moves inland and should be located over the Las Vegas region
by 12z Thu. system will develop into a broad closed low as it moves
towards the region during the day. A cool front will move across the
plains during early morning Thursday and upslope flow will commence
by midday over the area. Given the closed low moving towards the
area...modest mid lvl southwesterly flow aloft and upslope.
flow...conditions will be come favorable for rotating convection on
the plains...with the best chance attm n of highway 50.
As the low moves over the region Thu nite...wrap around precip is
fcst to develop along the I25 corridor....especially from Walsenburg
northward. Scattered showers will likely continue through the night
across most of the region.
Friday...
Cooler weather is likely this day. Upper closed low will likely be in
the vicinity of the KS/CO/NE border by midday...with northwesterly
flow over the region. Given the rather cold air aloft...we should
see lots of showers and weaker tsra over the region...especially
during the afternoon.
Saturday...
Weak mid lvl ridge will move over the region during this day. Expect
mainly isold tsra during the afternoon...mainly over the higher
trrn.
Sunday...
Weak southwesterly flow aloft will once again redevelop over the
region as another pacific wx system moves towards the region. Weak
cyclogenesis is fcst to develop over the raton mesa and this will
allow upslope to develop over the plains. if pattern develops...weak
favorable deep shear will develop and we may see a strong storm or
two over the plains. Scattered tsra are likely over the mtns on this
day.
Memorial Day into early next week...
Broad trough will continue over the west. However...models disagree
on intensity of this trough. GFS is deeper with the troughieness
while EC is more progressive and not as amplified. if GFS
verifies...then area will see a better chance of precip while the EC
pattern will promote more of a dry pattern. FWIW...GFS spaghetti
ensemble plots show a considerable amount of variability in the
troughs location/intensity... so confidence in fcst is low attm for
early next week. /Hodanish
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 337 AM MDT Tue May 24 2016
Main AVN concern will be low cigs this morning over portions of the
SE CO Plains, generally east of I-25 and N of hwy 50. This will most
likely affect KCOS, which could see some MVFR cigs until about 13Z-
15Z. Low clouds could potentially move into the KPUB vicinity, but
likelihood is too low ATTM to mention in the TAF. Otherwise, expect
VFR conditions for the next 24-30 hours and S-SW winds a bit breezy
this afternoon with gusts in the 20-30 kt range possible. A strong
to severe TS or two cannot be ruled out over the Plains, but any
storms will be well east of I-25 and most of the stronger convection
will remain in NE CO and KS. Rose
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...HODANISH
AVIATION...ROSE
[top]
Area Forecast Discussion
National Weather Service Denver/Boulder CO
320 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 320 AM MDT Tue May 24 2016
Southwest flow aloft will prevail around an upper level trough
over California. A weak short wave trough embedded in the flow
aloft and a surface low will move across the state today.
Southerly flow around the low will bring drier air to southern
Colorado while southeast to east winds farther north will
transport moisture into northeast Colorado. Expect an east/west
boundary/dry line to set up this afternoon. The southerly flow
will also likely cause a Denver Cyclone to form. As the airmass
moistens...low clouds are expected to spread across parts of
northeast Colorado early this morning. They may be slow to burn
off and thus lowered highs a few degrees, especially across
northern parts of northeast Colorado.
The HiRes models are in general agreement that convection will
initiate over/near the Denver metro area 2-3pm. Likely due to
convergence along the Denver Cyclone and the east/west boundary.
Storms will spread northeast through afternoon and evening hours.
Greatest threat for severe thunderstorms will be northeast of the
Denver area where CAPES will be 1000-2500 J/kg. Main threat will
be large hail. Damaging winds and a couple of tornadoes will also
be possible.
Drier air will spread across northeast Colorado overnight.
Convection is expected to exit the area by midnight and by
Wednesday morning mostly clear skies will prevail.
.LONG TERM...(Wednesday through Monday)
Issued at 320 AM MDT Tue May 24 2016
On Wednesday...the upper level trough will remain to the west with
a dry southwesterly flow aloft over north central and northeast
CO. The models show weak subsidence over the cwa through the day
...with the best low level moisture flushed out to the east into
western NE and northwestern KS. The models generate some QPF in
the aftn but it is mainly over the mountains. Wednesday night...
...a little surge is progged to push into the northeast corner of
CO. This boundary could act as a focus for nocturnal tstms around
06Z Wednesday night. Thursday through Friday...it will be cooler
and wetter across the cwa. The models have the next system near
the Four Corners region by 18z Thursday then move into western
NE/KS by Friday evening. As a result...there appears to be a
prolonged period of light to moderate rainfall over the region. The
models all show moderate QG ascent over the cwa Thursday
aftn/evng...with decreasing QG ascent late Thursday night and
Friday as the trough starts to shift to the east of CO. Highest
pops will be Thursday night...but still a good chance of showers
especially from the Front Range Foothills eastward on Friday.
There is a marginal threat for severe thunderstorms closer to the
KS border on Thursday aftn. It will also be a little cooler and
this may help to minimize the threat of severe thunderstorms. Over
the weekend...a drier westerly flow aloft will be over the state
on Saturday. It will be warmer with enough moisture around to keep
a slight chance of aftn/evng thunderstorms both days. By Sunday...
another trough in the Pacific Northwest will produce a southwesterly
flow aloft over CO.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 320 AM MDT Tue May 24 2016
Southeast winds will increase low level moisture and is expected
to produce low clouds across eastern Colorado. Ceilings of 1000 to
3000 feet are expected at the Denver airports from 11 to 15z, low
clouds may linger through the late morning, until 18z. Scattered
thunderstorms are expected to form after 20z. The best chance for
thunderstorms in the Denver area will be 20-23Z. Wind gusts to 40
knots, hail, and heavy rain will be possible with the
thunderstorms. Drier air will move into the area after 00z and
bring mostly clear skies by 06z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Meier
LONG TERM...Cooper
AVIATION...Meier
Area Forecast Discussion
National Weather Service Pueblo CO
1132 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1126 PM MDT Mon May 23 2016
KALS should see VFR conditions thru the next 24 HRS. KALS should
have gusty S to SW winds Tue afternoon and early evening. KCOS
and KPUB will have the potential for low stratus...mainly between
about 10Z and 15Z Tue...OTRW VFR conditions are expected. KCOS
and KPUB should see gusty S to SW winds in the afternoon and early
evening hours on Tue.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...28
[top]
Area Forecast Discussion
National Weather Service Grand Junction CO
1117 PM MDT MON MAY 23 2016
.SHORT TERM...(Tonight through Tuesday night)
Issued at 330 PM MDT Mon May 23 2016
A broad trough of low pressure remains over the Intermountain
West into next week bringing generally breezy, unsettled, and
cool conditions. Spokes of energy rotating through the trough from
SW to NE will drive our weather. This afternoon the first of
these spokes was lifting through NW Colorado. Scattered showers
north of I-70 will quickly end this evening. Tonight valley
inversions will allow temperatures to fall below normal and a
transient weak ridge will diminish the SW winds in the high
country.
Tuesday SW winds increase as the larger trough deepens along the
California coast. Moisture will be limited with only disorganized
forcing, so late-day showers will favor the northern-central
mountains. Overnight temperatures remain at or below normal.
.LONG TERM...(Wednesday through Monday)
Issued at 330 PM MDT Mon May 23 2016
Wednesday the trough works through California and weakens as it
moves into Utah-Arizona overnight. Chances of showers increase on
Thursday as its associated cold front work through the area.
Moisture and instability are limited with only weak cold advection
aloft so did not force POPs much above guidance for now.
Friday an unsettled NW flow aloft brings another round of late day
showers and isolated thunderstorms for all but SE Utah. After a
cool Thursday-Friday a warming trend begins. The next upper low
drops in from British Columbia over the weekend backing the flow
to SW again. This trough deepens along the California coast early
next week and may pass through this forecast area on June 2nd or
so.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1112 PM MDT Mon May 23 2016
Dry southwest flow will be in place across eastern Utah and
western Colorado for the next 24 hours. There is a less than 20
percent chance for late afternoon showers over the higher terrain
with gusty outflow winds to 40 mph the primary impact. Terminal
sites will remain VFR through the period.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...JOE
LONG TERM...JOE
AVIATION...JDC
Area Forecast Discussion
National Weather Service Pueblo CO
602 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 338 PM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area until about 03Z...with little chance of storms tomorrow. The
most likely area for these showers or storms would be across the
central mountains, the Pikes Peak Region and the far eastern plains.
These storms do not look all that intense but would pose threats of
lightning and erratic wind gusts to 50 mph. Storms right near the
eastern Colorado border could be stronger. Storms may produce local
MVFR, IFR or even LIFR flight conditions requiring circumnavigation
by pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
Area Forecast Discussion
National Weather Service Denver/Boulder CO
305 PM MDT MON MAY 23 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM MDT Mon May 23 2016
A jet max that pushed into southwestern Colorado earlier today
continues to push northeast, firing off convection over the
forecast area this afternoon. A shortwave ridge will be pushing
overhead tonight, however convection will spread northeast for
the rest of the afternoon and evening as a theta-e ridge advects
into the area from the south. The chance of showers and
thunderstorms will mainly confine itself overnight over the far
northeastern corner of the state. Skies will be clearing overnight
with winds becoming light, but at this time am not expecting any
fog to form. Minimum temperatures will be right around average
for this time of year.
More thunderstorms are expected Tuesday as a fast moving shortwave
ejected from an upper trough over California pushes over the area.
At the same time, a surface low should push into central Colorado,
with southeasterly surface winds helping to advect in higher
theta-e values. CAPE values between 1000-3300 J/kg are progged,
with the highest values over the far northern to northeastern
plains. Shear and instability is enough to prompt SPC to cover the
northeastern plains with an Enhanced Risk of severe storms. Large
hail and strong damaging winds are likely from the stronger
storms, but cannot rule out a tornado forming with good turning in
the winds from the surface upwards. Temperatures will warm about 5
to 10 degrees over todays readings.
.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM MDT Mon May 23 2016
Models continue to indicate the passage of a couple of weak mid-
level instability axes/shortwave troughs over the forecast area
during the afternoon and evening hours Tuesday and Wednesday. The
stronger of these disturbances appears to pass over the area late
on Tuesday impacting mainly the northeast corner of the CWA
during the evening. Could see t-storms forming along a wind
shift/dry line which slowly translates northeast with the
shortwave during the evening. Best sfc based capes and instability
east of this boundary where gusty sely sfc winds continue to
advect in lower 60s wetbulb temps. A few storms may produce hail...
stg gusty winds and brief moderate to heavy rainfall rates. Cannot
rule out a severe storm east of a Briggsdale-to-Akron line. The
late Wednesday disturbance being carried along by strengthening
swly flow aloft appears weaker and not as moist. Yet may still see
isolated to widely scattered showers and t-storms produce gusty
winds and light to moderate rainfall over and along the Front
Range during the late afternoon and evening hours.
During the Thursday-Friday time period...the poorly organized long
wave upper trough over the Great Basin is still progged to migrate
eastward across the Rocky Mountain region during this period.
Models now in better agreement as they all show this open wave
trough bringing cooler air and a decent amount of moisture to the
state. Should see an increase in shower and t-storm coverage
both days. Thursday afternoon and evening appears to be the
optimum time for shower and t-storm development along and east of
the Front Range with the upper low passing to south and a moist post-
frontal low-level upslope flow on the plains. CAPES off interactive
soundings not terribly great due largely to cooler temps and
increasing cloud cover. However cannot rule out a couple of t-storms
producing locally heavy rainfall and hail. By Friday...models
show the CWA on the back side of the upper trough...but a weak
upr air disturbance swinging out of the nrn Colorado mtns and srn
Wyoming during the afternoon could generate additional showers and
perhaps a few t-storms. Although their intensity should not be
not as great as the day before. Temps Thursday and Friday expected
to drop 10 deg f or so from those on Wednesday.
Saturday through Monday...trough moves east and washes out over
the northern Great Basins placing the fcst area under a gentle
near zonal flow aloft on Saturday. Sunday and Monday the area
comes under the influence of a warmer south-southwesterly flow
with just a slight chance of heat driven afternoon and evening
t-storms each day.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 305 PM MDT Mon May 23 2016
VFR conditions are expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains.
Wind gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward light drainage
tonight. At this time, no widespread fog is expected, however
there could be some patchy areas along the South Platte River
valley. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Kriederman
LONG TERM...Baker
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Denver/Boulder CO
144 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 139 PM MDT Mon May 23 2016
VFR conditions expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains. Wind
gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward drainage
tonight. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Pueblo CO
1106 AM MDT MON MAY 23 2016
.SHORT TERM...(Today and tonight)
Issued at 342 AM MDT Mon May 23 2016
Shallow cold front was dropping southward through the plains this
morning, bringing a shift to north winds and slightly higher
dewpoints to most areas along and east of I-25. Front looks like it
will become stationary near the NM border by mid-morning, before
lifting slowly back northward through the afternoon and evening as
surface pressure begins to fall in response to next upper wave
dropping south along the west coast. Models suggest some modest low
level moisture and instability may pool along and north of the
boundary by late afternoon, with perhaps some isolated tsra
developing along the palmer divide and near the ks border as weak
moisture convergence may be enough to generate convection. 0-6km
shear will be sufficient for a strong to severe storms if convection
can develop, although best chances for severe will likely stay just
north and east of the area where deeper instability lies. Central
mountains could also see a brief tsra or two as well, though again
coverage/intensity will be sparse/weak. Max temps will continue to
drift downward a few degrees, with most noticeable cooling over
the eastern plains behind the front. Overnight, any convection
will end quickly in the evening as strongest forcing continues to
stay just north and east of the region. By early Tue morning, cold
front will slosh back southward through the plains, with perhaps
enough low level moisture for some stratus along the KS border
toward sunrise.
.LONG TERM...(Tuesday through Sunday)
Issued at 342 AM MDT Mon May 23 2016
...Best chance of rain on Thursday...
Extended portion of the forecast still looks pretty tame, and models
are in good agreement through the end of the week and into the
weekend.
Tuesday should be the warmest day of the period, with highs likely
topping out in the mid to upper 80s for the Plains...and 60s to low
70s for the higher elevations. Could be a bit breezy in the
afternoon as SW winds in the 30-35 kt range mix down to the surface.
Best chance for storms late in the afternoon will be mainly over NE
CO...so have maintained nil POPs for most of the area. Risk for
severe storms could sneak into Kiowa County by late afternoon or
early eve...so could see a slight risk of severe once again near
the KS border. SW flow pattern continues on Wed with continued
warm conditions and low threat of convection. Best chance for any
precip will be over the Pikes Pk region and Upper Arkansas Valley.
Thursday morning, the upper low to our west will finally start
moving into our area...reaching the 4 Corners area by mid day.
This will bring an increased threat of showers and storms...first to
the central and SW mountains early in the day...and then to the I-25
corridor and Plains by afternoon, as the upper low moves eastward
into KS by Thu evening. Upslope flow, especially on the backside of
the upper circulation, will put the best chance of precip over the
eastern mountains and southern Front Range. Could potentially see
some localized heavy rainfall from this system so will have to keep
an eye out for that. Severe potential looks low over the area with
generally low CAPE...but the latest NAM does bring a ribbon of
higher CAPE into extreme eastern CO in the afternoon, so will
have to see how much low-level moisture can make its way into the
Plains. Latest guidance pushes the trough eastward fairly quickly on
Friday, so should see fewer showers and storms on Friday but still
on the cool side of climatology for afternoon temps. The pattern
reloads for the weekend as quasi-zonal flow transitions to SW flow
ahead of the next trough developing over the PacNW. Rose
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1023 AM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area...primarily from 18Z to 03Z. The most likely area for these
showers or storms would be across the central mountains, the
Pikes Peak Region and the far eastern plains. These storms do not
look all that intense but would pose threats of lightning and
erratic wind gusts to 50 mph. Storms right near the eastern
Colorado border could be stronger. Storms may produce local MVFR,
IFR or even LIFR flight conditions requiring circumnavigation by
pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...LW
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1029 AM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 431 AM MDT Mon May 23 2016
VFR through tonight. Scattered thunderstorms are expected this
afternoon, with the main threat between 20z and 00z. Wind gusts to
40 knots and brief heavy rain are possible with the storms.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Pueblo CO
1112 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1111 PM MDT Sun May 22 2016
A cold front will drop south across KCOS and KPUB through 06z
tonight with a northerly wind shift. Expect VFR conditions at all
three terminals through the next 24 hours. A few showers and
thunderstorms will be possible on Monday afternoon over the Palmer
Divide, and should remain north of KCOS through the evening.
Southerly winds will be gusty at all three terminals Monday
afternoon into the evening. Mozley
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
AVIATION...MOZLEY
Area Forecast Discussion
National Weather Service Grand Junction CO
1051 PM MDT SUN MAY 22 2016
.SHORT TERM...(This evening through Monday night)
Issued at 400 PM MDT Sun May 22 2016
H5 hand analysis at 12z had a dominant ridge over the central
CONUS with low pressure systems along both right and left coastal
states. Our CWA is squeezed between the ridge and west coast low
leaving moderately fast southwest flow aloft. So far cloud cover
is keeping much of the winds at bay in the valleys...but at
ridge tops and near showers gusty winds will continue into the
evening. Expect showers to quickly die off after sunset with loss
of heating and under subsidence behind a passing wave. Downstream
blocking over the eastern states over the next 24 to 36 hours
leaves low pressure over the northern rockies and intermountain
west. This leaves southwest flow in place across the region with
little moisture advection. The 1.5 PVU progs suggest another wave
passing through Monday afternoon during peak heating and will lead
to another round of convection over the higher terrain over the
northern mountains. Temperatures will be slightly warmer on Monday
but stay below normal for this time of May.
.LONG TERM...(Tuesday through Sunday)
Issued at 400 PM MDT Sun May 22 2016
The downstream block will gradually break down by mid week and the
western trough will be allowed to traverse across the Rockies
Thursday. Wednesday will be a mirror of Tuesday with only isolated
afternoon convection anticipated in the afternoon. The passage of
the trough will bring an uptick to the convection Thursday which
will linger into Friday with cooler temperatures aloft aiding in
afternoon instability in northerly flow aloft. The next Pacific
system drops into the west Saturday and southerly flow return to
our CWA going into next weekend. At this time winds seem more of a
concern than precipitation. Temperatures remain below normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1043 PM MDT Sun May 22 2016
A weak cold front will continue to move slowly east out of the
forecast area tonight with winds diminishing overnight. Weaker
flow will return on Monday...however...breezy gusts are expected
at all TAF sites by the afternoon hours. Residual moisture and
instability will allow scattered afternoon showers and isolated
thunderstorms north of I-70 before diminishing by early evening.
This shower activity is not expected to impact airport operations.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...15
LONG TERM...15
AVIATION...MPM
Area Forecast Discussion
National Weather Service Pueblo CO
800 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 310 PM MDT Sun May 22 2016
Dry southwest flow will result in VFR over most of the flight area
for most of the forecast period. The far eastern plains, along the
eastern border, may see exception to this for a brief period late
this afternoon into the evening as storms fire along a dryline in
this vicinity. Pilots may have to navigate dryline storms in this
area...generally 22z-02z. KCOS...KPUB and KALS TAF sites should
remain VFR next 24 hours.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
Area Forecast Discussion
National Weather Service Denver/Boulder CO
756 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 748 PM MDT Sun May 22 2016
Sct high based showers and a few storms will move across the nern
plains thru midnight and then should end shortly thereafter as a
disturbance moves quickly across.
&&
.SHORT TERM...(This evening through Monday)
Issued at 345 PM MDT Sun May 22 2016
Have seen a few showers develop over Larimer County over the past
couple hours, with additional showers expected over the next few
hours. A short wave seems to be embedded in the prevailing
southwest flow which is producing the shower activity across
northwest Colorado and the northern mountains. The HRRR and RAP
models indicate that a band of shower activity related to this
short wave will develop on the plains after 02z. The I-25 corridor
should remain dry, but areast to the east of Fort Morgan should
see an hour or so of shower activity between 02z and 06z. Showers
will move out of the state by 06z with clearing skies overnight. A
weak surge of northerly winds across the plains will follow the
passage of the evening shower activity.
Additional cooling is expected tomorrow as weak northerly flow
continues. More thunderstorm activity is expected over the
mountains tomorrow afternoon as the state remains under southwest
flow aloft and an upper jet moves over the state, bringing a bit
more dynamic forcing than we have had the past couple days. Late
in the afternoon showers are then expected to spread out onto the
plains.
.LONG TERM...(Monday night through Sunday)
Issued at 345 PM MDT Sun May 22 2016
A cross CONUS blocking trough-ridge-trough pattern keeps a warm
and relatively dry swly flow over Colorado through mid-week.
Models show a couple of weak mid-level pertabations carried along
in this flow and passing over nern portions of the cwa Monday
evening and again Tuesday afternoon and early evening. Storms
forming on a wind shift line just east of the I-25 corridor is
forecast to shift northeast across weld...Adams and Morgan
counties Monday evening. Sfc based capes and instability may be
sufficient to support a few strong storms capable of small hail...
stg gusty winds and brief heavy rainfall. This storm area will
shift east-northeast with the shortwave passing through the nern
corner of the state during the mid to late evening hours. Models
indicate 3-hour qpf amounts in the 0-20-0.30 inch range out there.
The late Tuesday shortwave appears a bit weaker and farther
north with more of an impact on the northern Front Range and
northern I-25 corridor around Ft. Collins. Brief rainfall land
gusty winds probably main output from these high based cells.
Wednesday looks drier with strong mid-level subsidence..and temps
generally around average with a downslope flow off the Front
Range. Strong diabatic heating should still manage to generate a
few late day showers/t-storms over the high terrain.
Thursday-Friday time period...open wave upper trough passing over
the Great Basin is still progged to makes slow eastward progress
across Colorado during the period. GFS has come into closer
agreement with the European model which has changed little during
the past few runs. Both models as well as the DGEX and Canadian
models all show this trough and its cooler temperatures and
moisture enhancing shower/storm chances across the cwa. Best
chance for measurable precip appears to be late Thursday
afternoon/evening over and along the Front Range and Palmer
Divide...and on the northeast plains Friday afternoon with the
passage of a cold front. Would not rule out a few pockets of heavy
rainfall with rising precipitable water with this system.
By Saturday...models show this trough and front moving out across
the Great Plains and a shortwave upper ridge building over the
state...bring warmer and drier conditions to the area. This
trend continues Sunday with southerly flow and an amplifying
ridge.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 748 PM MDT Sun May 22 2016
An outflow bndry fm high based showers is moving south quickly
and should reach dia by 0215Z. Winds gusts to 30 mph fm the north
will occur for a brief period of time but should decrease by 03z.
A few high based showers/storms are developing behind the bndry
so may have to mention vcts at dia until 03z if they continue to
dvlp southward.
Overnight winds will become more ely by midnight and then sely
by 09z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...RPK
SHORT TERM...Dankers
LONG TERM...Baker
AVIATION...RPK
Area Forecast Discussion
National Weather Service Pueblo CO
342 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 337 AM MDT Tue May 24 2016
...Warm and generally dry today...
Currently...low clouds are slowly expanding over the NE portion of
the CWA, and will likely continue to expand over the next few hours.
Areas of stratus will be most likely east of I-25 and north of Hwy
50. Low cloud deck should dissipate by mid morning, leaving mostly
sunny skies for the rest of today.
Main concern today will be the potential for strong to severe storms
over a small portion of the CWA, generally from Eastern Pueblo
County eastward to the KS border, and north of Hgwy 50. A surface
low will depend to about 996 mb this afternoon, setting up over
Bent and Prowers counties late in the day. North of the surface low,
surface winds will back strongly in a moisture rich environment with
CAPE approaching 3000 J/kg. Along with bulk shear in the 40-50 kt
range, this environment will be conducive to supercell development.
The surface low will shift northward by late afternoon, leaving only
a short window of opportunity for storms to develop in our area. The
NAM keeps the area free of storms, while other high res solutions
such as the ARW and NMM develop a couple cells in this area late in
the afternoon. Given the potential, will introduce low POPs for this
period. The severe threat looks mainly confined to Kiowa County, but
could shift to include more or less of our CWA depending on the
surface low development. Since all modes of severe wx would be
possible with any storms that form, will have to watch for this
potential later this afternoon.
Otherwise, just a warm and breezy day, with temps in the mid to
upper 80s over the plains and south to southwest winds gusting in
the 20-30 kt range this afternoon. Dry SW flow will increase by
evening, leaving us with a clear night with seasonal temps in the
40s for the plains and 30s for the high valleys. Rose
.LONG TERM...(Wednesday through Monday)
Issued at 337 AM MDT Tue May 24 2016
Troughieness over the western conus will keep the pattern potentially
active over the region during this period. The most active day is
expected to be Thursday as strong to severe storms may occur.
Friday should be cool with quite a few showers/-tsra over the
region.
Wednesday...
Primary trough will still be just offshore of the Calif coast and
will be moving inland during this day. Mid lvl low over the region
will be southwesterly with a weak shortwave ridge moving over the
area. Expect mainly dry warm weather will only an isold tsra over
the higher trrn...and possibly a high based tsra over the palmer
dvd.
Thursday...
Trough moves inland and should be located over the Las Vegas region
by 12z Thu. system will develop into a broad closed low as it moves
towards the region during the day. A cool front will move across the
plains during early morning Thursday and upslope flow will commence
by midday over the area. Given the closed low moving towards the
area...modest mid lvl southwesterly flow aloft and upslope.
flow...conditions will be come favorable for rotating convection on
the plains...with the best chance attm n of highway 50.
As the low moves over the region Thu nite...wrap around precip is
fcst to develop along the I25 corridor....especially from Walsenburg
northward. Scattered showers will likely continue through the night
across most of the region.
Friday...
Cooler weather is likely this day. Upper closed low will likely be in
the vicinity of the KS/CO/NE border by midday...with northwesterly
flow over the region. Given the rather cold air aloft...we should
see lots of showers and weaker tsra over the region...especially
during the afternoon.
Saturday...
Weak mid lvl ridge will move over the region during this day. Expect
mainly isold tsra during the afternoon...mainly over the higher
trrn.
Sunday...
Weak southwesterly flow aloft will once again redevelop over the
region as another pacific wx system moves towards the region. Weak
cyclogenesis is fcst to develop over the raton mesa and this will
allow upslope to develop over the plains. if pattern develops...weak
favorable deep shear will develop and we may see a strong storm or
two over the plains. Scattered tsra are likely over the mtns on this
day.
Memorial Day into early next week...
Broad trough will continue over the west. However...models disagree
on intensity of this trough. GFS is deeper with the troughieness
while EC is more progressive and not as amplified. if GFS
verifies...then area will see a better chance of precip while the EC
pattern will promote more of a dry pattern. FWIW...GFS spaghetti
ensemble plots show a considerable amount of variability in the
troughs location/intensity... so confidence in fcst is low attm for
early next week. /Hodanish
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 337 AM MDT Tue May 24 2016
Main AVN concern will be low cigs this morning over portions of the
SE CO Plains, generally east of I-25 and N of hwy 50. This will most
likely affect KCOS, which could see some MVFR cigs until about 13Z-
15Z. Low clouds could potentially move into the KPUB vicinity, but
likelihood is too low ATTM to mention in the TAF. Otherwise, expect
VFR conditions for the next 24-30 hours and S-SW winds a bit breezy
this afternoon with gusts in the 20-30 kt range possible. A strong
to severe TS or two cannot be ruled out over the Plains, but any
storms will be well east of I-25 and most of the stronger convection
will remain in NE CO and KS. Rose
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...HODANISH
AVIATION...ROSE
[top]
Area Forecast Discussion
National Weather Service Denver/Boulder CO
320 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 320 AM MDT Tue May 24 2016
Southwest flow aloft will prevail around an upper level trough
over California. A weak short wave trough embedded in the flow
aloft and a surface low will move across the state today.
Southerly flow around the low will bring drier air to southern
Colorado while southeast to east winds farther north will
transport moisture into northeast Colorado. Expect an east/west
boundary/dry line to set up this afternoon. The southerly flow
will also likely cause a Denver Cyclone to form. As the airmass
moistens...low clouds are expected to spread across parts of
northeast Colorado early this morning. They may be slow to burn
off and thus lowered highs a few degrees, especially across
northern parts of northeast Colorado.
The HiRes models are in general agreement that convection will
initiate over/near the Denver metro area 2-3pm. Likely due to
convergence along the Denver Cyclone and the east/west boundary.
Storms will spread northeast through afternoon and evening hours.
Greatest threat for severe thunderstorms will be northeast of the
Denver area where CAPES will be 1000-2500 J/kg. Main threat will
be large hail. Damaging winds and a couple of tornadoes will also
be possible.
Drier air will spread across northeast Colorado overnight.
Convection is expected to exit the area by midnight and by
Wednesday morning mostly clear skies will prevail.
.LONG TERM...(Wednesday through Monday)
Issued at 320 AM MDT Tue May 24 2016
On Wednesday...the upper level trough will remain to the west with
a dry southwesterly flow aloft over north central and northeast
CO. The models show weak subsidence over the cwa through the day
...with the best low level moisture flushed out to the east into
western NE and northwestern KS. The models generate some QPF in
the aftn but it is mainly over the mountains. Wednesday night...
...a little surge is progged to push into the northeast corner of
CO. This boundary could act as a focus for nocturnal tstms around
06Z Wednesday night. Thursday through Friday...it will be cooler
and wetter across the cwa. The models have the next system near
the Four Corners region by 18z Thursday then move into western
NE/KS by Friday evening. As a result...there appears to be a
prolonged period of light to moderate rainfall over the region. The
models all show moderate QG ascent over the cwa Thursday
aftn/evng...with decreasing QG ascent late Thursday night and
Friday as the trough starts to shift to the east of CO. Highest
pops will be Thursday night...but still a good chance of showers
especially from the Front Range Foothills eastward on Friday.
There is a marginal threat for severe thunderstorms closer to the
KS border on Thursday aftn. It will also be a little cooler and
this may help to minimize the threat of severe thunderstorms. Over
the weekend...a drier westerly flow aloft will be over the state
on Saturday. It will be warmer with enough moisture around to keep
a slight chance of aftn/evng thunderstorms both days. By Sunday...
another trough in the Pacific Northwest will produce a southwesterly
flow aloft over CO.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 320 AM MDT Tue May 24 2016
Southeast winds will increase low level moisture and is expected
to produce low clouds across eastern Colorado. Ceilings of 1000 to
3000 feet are expected at the Denver airports from 11 to 15z, low
clouds may linger through the late morning, until 18z. Scattered
thunderstorms are expected to form after 20z. The best chance for
thunderstorms in the Denver area will be 20-23Z. Wind gusts to 40
knots, hail, and heavy rain will be possible with the
thunderstorms. Drier air will move into the area after 00z and
bring mostly clear skies by 06z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Meier
LONG TERM...Cooper
AVIATION...Meier
Area Forecast Discussion
National Weather Service Pueblo CO
1132 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1126 PM MDT Mon May 23 2016
KALS should see VFR conditions thru the next 24 HRS. KALS should
have gusty S to SW winds Tue afternoon and early evening. KCOS
and KPUB will have the potential for low stratus...mainly between
about 10Z and 15Z Tue...OTRW VFR conditions are expected. KCOS
and KPUB should see gusty S to SW winds in the afternoon and early
evening hours on Tue.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...28
[top]
Area Forecast Discussion
National Weather Service Grand Junction CO
1117 PM MDT MON MAY 23 2016
.SHORT TERM...(Tonight through Tuesday night)
Issued at 330 PM MDT Mon May 23 2016
A broad trough of low pressure remains over the Intermountain
West into next week bringing generally breezy, unsettled, and
cool conditions. Spokes of energy rotating through the trough from
SW to NE will drive our weather. This afternoon the first of
these spokes was lifting through NW Colorado. Scattered showers
north of I-70 will quickly end this evening. Tonight valley
inversions will allow temperatures to fall below normal and a
transient weak ridge will diminish the SW winds in the high
country.
Tuesday SW winds increase as the larger trough deepens along the
California coast. Moisture will be limited with only disorganized
forcing, so late-day showers will favor the northern-central
mountains. Overnight temperatures remain at or below normal.
.LONG TERM...(Wednesday through Monday)
Issued at 330 PM MDT Mon May 23 2016
Wednesday the trough works through California and weakens as it
moves into Utah-Arizona overnight. Chances of showers increase on
Thursday as its associated cold front work through the area.
Moisture and instability are limited with only weak cold advection
aloft so did not force POPs much above guidance for now.
Friday an unsettled NW flow aloft brings another round of late day
showers and isolated thunderstorms for all but SE Utah. After a
cool Thursday-Friday a warming trend begins. The next upper low
drops in from British Columbia over the weekend backing the flow
to SW again. This trough deepens along the California coast early
next week and may pass through this forecast area on June 2nd or
so.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1112 PM MDT Mon May 23 2016
Dry southwest flow will be in place across eastern Utah and
western Colorado for the next 24 hours. There is a less than 20
percent chance for late afternoon showers over the higher terrain
with gusty outflow winds to 40 mph the primary impact. Terminal
sites will remain VFR through the period.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...JOE
LONG TERM...JOE
AVIATION...JDC
Area Forecast Discussion
National Weather Service Pueblo CO
602 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 338 PM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area until about 03Z...with little chance of storms tomorrow. The
most likely area for these showers or storms would be across the
central mountains, the Pikes Peak Region and the far eastern plains.
These storms do not look all that intense but would pose threats of
lightning and erratic wind gusts to 50 mph. Storms right near the
eastern Colorado border could be stronger. Storms may produce local
MVFR, IFR or even LIFR flight conditions requiring circumnavigation
by pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
Area Forecast Discussion
National Weather Service Denver/Boulder CO
305 PM MDT MON MAY 23 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM MDT Mon May 23 2016
A jet max that pushed into southwestern Colorado earlier today
continues to push northeast, firing off convection over the
forecast area this afternoon. A shortwave ridge will be pushing
overhead tonight, however convection will spread northeast for
the rest of the afternoon and evening as a theta-e ridge advects
into the area from the south. The chance of showers and
thunderstorms will mainly confine itself overnight over the far
northeastern corner of the state. Skies will be clearing overnight
with winds becoming light, but at this time am not expecting any
fog to form. Minimum temperatures will be right around average
for this time of year.
More thunderstorms are expected Tuesday as a fast moving shortwave
ejected from an upper trough over California pushes over the area.
At the same time, a surface low should push into central Colorado,
with southeasterly surface winds helping to advect in higher
theta-e values. CAPE values between 1000-3300 J/kg are progged,
with the highest values over the far northern to northeastern
plains. Shear and instability is enough to prompt SPC to cover the
northeastern plains with an Enhanced Risk of severe storms. Large
hail and strong damaging winds are likely from the stronger
storms, but cannot rule out a tornado forming with good turning in
the winds from the surface upwards. Temperatures will warm about 5
to 10 degrees over todays readings.
.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM MDT Mon May 23 2016
Models continue to indicate the passage of a couple of weak mid-
level instability axes/shortwave troughs over the forecast area
during the afternoon and evening hours Tuesday and Wednesday. The
stronger of these disturbances appears to pass over the area late
on Tuesday impacting mainly the northeast corner of the CWA
during the evening. Could see t-storms forming along a wind
shift/dry line which slowly translates northeast with the
shortwave during the evening. Best sfc based capes and instability
east of this boundary where gusty sely sfc winds continue to
advect in lower 60s wetbulb temps. A few storms may produce hail...
stg gusty winds and brief moderate to heavy rainfall rates. Cannot
rule out a severe storm east of a Briggsdale-to-Akron line. The
late Wednesday disturbance being carried along by strengthening
swly flow aloft appears weaker and not as moist. Yet may still see
isolated to widely scattered showers and t-storms produce gusty
winds and light to moderate rainfall over and along the Front
Range during the late afternoon and evening hours.
During the Thursday-Friday time period...the poorly organized long
wave upper trough over the Great Basin is still progged to migrate
eastward across the Rocky Mountain region during this period.
Models now in better agreement as they all show this open wave
trough bringing cooler air and a decent amount of moisture to the
state. Should see an increase in shower and t-storm coverage
both days. Thursday afternoon and evening appears to be the
optimum time for shower and t-storm development along and east of
the Front Range with the upper low passing to south and a moist post-
frontal low-level upslope flow on the plains. CAPES off interactive
soundings not terribly great due largely to cooler temps and
increasing cloud cover. However cannot rule out a couple of t-storms
producing locally heavy rainfall and hail. By Friday...models
show the CWA on the back side of the upper trough...but a weak
upr air disturbance swinging out of the nrn Colorado mtns and srn
Wyoming during the afternoon could generate additional showers and
perhaps a few t-storms. Although their intensity should not be
not as great as the day before. Temps Thursday and Friday expected
to drop 10 deg f or so from those on Wednesday.
Saturday through Monday...trough moves east and washes out over
the northern Great Basins placing the fcst area under a gentle
near zonal flow aloft on Saturday. Sunday and Monday the area
comes under the influence of a warmer south-southwesterly flow
with just a slight chance of heat driven afternoon and evening
t-storms each day.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 305 PM MDT Mon May 23 2016
VFR conditions are expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains.
Wind gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward light drainage
tonight. At this time, no widespread fog is expected, however
there could be some patchy areas along the South Platte River
valley. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Kriederman
LONG TERM...Baker
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Denver/Boulder CO
144 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 139 PM MDT Mon May 23 2016
VFR conditions expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains. Wind
gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward drainage
tonight. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Pueblo CO
1106 AM MDT MON MAY 23 2016
.SHORT TERM...(Today and tonight)
Issued at 342 AM MDT Mon May 23 2016
Shallow cold front was dropping southward through the plains this
morning, bringing a shift to north winds and slightly higher
dewpoints to most areas along and east of I-25. Front looks like it
will become stationary near the NM border by mid-morning, before
lifting slowly back northward through the afternoon and evening as
surface pressure begins to fall in response to next upper wave
dropping south along the west coast. Models suggest some modest low
level moisture and instability may pool along and north of the
boundary by late afternoon, with perhaps some isolated tsra
developing along the palmer divide and near the ks border as weak
moisture convergence may be enough to generate convection. 0-6km
shear will be sufficient for a strong to severe storms if convection
can develop, although best chances for severe will likely stay just
north and east of the area where deeper instability lies. Central
mountains could also see a brief tsra or two as well, though again
coverage/intensity will be sparse/weak. Max temps will continue to
drift downward a few degrees, with most noticeable cooling over
the eastern plains behind the front. Overnight, any convection
will end quickly in the evening as strongest forcing continues to
stay just north and east of the region. By early Tue morning, cold
front will slosh back southward through the plains, with perhaps
enough low level moisture for some stratus along the KS border
toward sunrise.
.LONG TERM...(Tuesday through Sunday)
Issued at 342 AM MDT Mon May 23 2016
...Best chance of rain on Thursday...
Extended portion of the forecast still looks pretty tame, and models
are in good agreement through the end of the week and into the
weekend.
Tuesday should be the warmest day of the period, with highs likely
topping out in the mid to upper 80s for the Plains...and 60s to low
70s for the higher elevations. Could be a bit breezy in the
afternoon as SW winds in the 30-35 kt range mix down to the surface.
Best chance for storms late in the afternoon will be mainly over NE
CO...so have maintained nil POPs for most of the area. Risk for
severe storms could sneak into Kiowa County by late afternoon or
early eve...so could see a slight risk of severe once again near
the KS border. SW flow pattern continues on Wed with continued
warm conditions and low threat of convection. Best chance for any
precip will be over the Pikes Pk region and Upper Arkansas Valley.
Thursday morning, the upper low to our west will finally start
moving into our area...reaching the 4 Corners area by mid day.
This will bring an increased threat of showers and storms...first to
the central and SW mountains early in the day...and then to the I-25
corridor and Plains by afternoon, as the upper low moves eastward
into KS by Thu evening. Upslope flow, especially on the backside of
the upper circulation, will put the best chance of precip over the
eastern mountains and southern Front Range. Could potentially see
some localized heavy rainfall from this system so will have to keep
an eye out for that. Severe potential looks low over the area with
generally low CAPE...but the latest NAM does bring a ribbon of
higher CAPE into extreme eastern CO in the afternoon, so will
have to see how much low-level moisture can make its way into the
Plains. Latest guidance pushes the trough eastward fairly quickly on
Friday, so should see fewer showers and storms on Friday but still
on the cool side of climatology for afternoon temps. The pattern
reloads for the weekend as quasi-zonal flow transitions to SW flow
ahead of the next trough developing over the PacNW. Rose
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1023 AM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area...primarily from 18Z to 03Z. The most likely area for these
showers or storms would be across the central mountains, the
Pikes Peak Region and the far eastern plains. These storms do not
look all that intense but would pose threats of lightning and
erratic wind gusts to 50 mph. Storms right near the eastern
Colorado border could be stronger. Storms may produce local MVFR,
IFR or even LIFR flight conditions requiring circumnavigation by
pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...LW
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1029 AM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 431 AM MDT Mon May 23 2016
VFR through tonight. Scattered thunderstorms are expected this
afternoon, with the main threat between 20z and 00z. Wind gusts to
40 knots and brief heavy rain are possible with the storms.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Pueblo CO
1112 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1111 PM MDT Sun May 22 2016
A cold front will drop south across KCOS and KPUB through 06z
tonight with a northerly wind shift. Expect VFR conditions at all
three terminals through the next 24 hours. A few showers and
thunderstorms will be possible on Monday afternoon over the Palmer
Divide, and should remain north of KCOS through the evening.
Southerly winds will be gusty at all three terminals Monday
afternoon into the evening. Mozley
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
AVIATION...MOZLEY
Area Forecast Discussion
National Weather Service Grand Junction CO
1051 PM MDT SUN MAY 22 2016
.SHORT TERM...(This evening through Monday night)
Issued at 400 PM MDT Sun May 22 2016
H5 hand analysis at 12z had a dominant ridge over the central
CONUS with low pressure systems along both right and left coastal
states. Our CWA is squeezed between the ridge and west coast low
leaving moderately fast southwest flow aloft. So far cloud cover
is keeping much of the winds at bay in the valleys...but at
ridge tops and near showers gusty winds will continue into the
evening. Expect showers to quickly die off after sunset with loss
of heating and under subsidence behind a passing wave. Downstream
blocking over the eastern states over the next 24 to 36 hours
leaves low pressure over the northern rockies and intermountain
west. This leaves southwest flow in place across the region with
little moisture advection. The 1.5 PVU progs suggest another wave
passing through Monday afternoon during peak heating and will lead
to another round of convection over the higher terrain over the
northern mountains. Temperatures will be slightly warmer on Monday
but stay below normal for this time of May.
.LONG TERM...(Tuesday through Sunday)
Issued at 400 PM MDT Sun May 22 2016
The downstream block will gradually break down by mid week and the
western trough will be allowed to traverse across the Rockies
Thursday. Wednesday will be a mirror of Tuesday with only isolated
afternoon convection anticipated in the afternoon. The passage of
the trough will bring an uptick to the convection Thursday which
will linger into Friday with cooler temperatures aloft aiding in
afternoon instability in northerly flow aloft. The next Pacific
system drops into the west Saturday and southerly flow return to
our CWA going into next weekend. At this time winds seem more of a
concern than precipitation. Temperatures remain below normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1043 PM MDT Sun May 22 2016
A weak cold front will continue to move slowly east out of the
forecast area tonight with winds diminishing overnight. Weaker
flow will return on Monday...however...breezy gusts are expected
at all TAF sites by the afternoon hours. Residual moisture and
instability will allow scattered afternoon showers and isolated
thunderstorms north of I-70 before diminishing by early evening.
This shower activity is not expected to impact airport operations.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...15
LONG TERM...15
AVIATION...MPM
Area Forecast Discussion
National Weather Service Pueblo CO
800 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 310 PM MDT Sun May 22 2016
Dry southwest flow will result in VFR over most of the flight area
for most of the forecast period. The far eastern plains, along the
eastern border, may see exception to this for a brief period late
this afternoon into the evening as storms fire along a dryline in
this vicinity. Pilots may have to navigate dryline storms in this
area...generally 22z-02z. KCOS...KPUB and KALS TAF sites should
remain VFR next 24 hours.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
Area Forecast Discussion
National Weather Service Denver/Boulder CO
756 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 748 PM MDT Sun May 22 2016
Sct high based showers and a few storms will move across the nern
plains thru midnight and then should end shortly thereafter as a
disturbance moves quickly across.
&&
.SHORT TERM...(This evening through Monday)
Issued at 345 PM MDT Sun May 22 2016
Have seen a few showers develop over Larimer County over the past
couple hours, with additional showers expected over the next few
hours. A short wave seems to be embedded in the prevailing
southwest flow which is producing the shower activity across
northwest Colorado and the northern mountains. The HRRR and RAP
models indicate that a band of shower activity related to this
short wave will develop on the plains after 02z. The I-25 corridor
should remain dry, but areast to the east of Fort Morgan should
see an hour or so of shower activity between 02z and 06z. Showers
will move out of the state by 06z with clearing skies overnight. A
weak surge of northerly winds across the plains will follow the
passage of the evening shower activity.
Additional cooling is expected tomorrow as weak northerly flow
continues. More thunderstorm activity is expected over the
mountains tomorrow afternoon as the state remains under southwest
flow aloft and an upper jet moves over the state, bringing a bit
more dynamic forcing than we have had the past couple days. Late
in the afternoon showers are then expected to spread out onto the
plains.
.LONG TERM...(Monday night through Sunday)
Issued at 345 PM MDT Sun May 22 2016
A cross CONUS blocking trough-ridge-trough pattern keeps a warm
and relatively dry swly flow over Colorado through mid-week.
Models show a couple of weak mid-level pertabations carried along
in this flow and passing over nern portions of the cwa Monday
evening and again Tuesday afternoon and early evening. Storms
forming on a wind shift line just east of the I-25 corridor is
forecast to shift northeast across weld...Adams and Morgan
counties Monday evening. Sfc based capes and instability may be
sufficient to support a few strong storms capable of small hail...
stg gusty winds and brief heavy rainfall. This storm area will
shift east-northeast with the shortwave passing through the nern
corner of the state during the mid to late evening hours. Models
indicate 3-hour qpf amounts in the 0-20-0.30 inch range out there.
The late Tuesday shortwave appears a bit weaker and farther
north with more of an impact on the northern Front Range and
northern I-25 corridor around Ft. Collins. Brief rainfall land
gusty winds probably main output from these high based cells.
Wednesday looks drier with strong mid-level subsidence..and temps
generally around average with a downslope flow off the Front
Range. Strong diabatic heating should still manage to generate a
few late day showers/t-storms over the high terrain.
Thursday-Friday time period...open wave upper trough passing over
the Great Basin is still progged to makes slow eastward progress
across Colorado during the period. GFS has come into closer
agreement with the European model which has changed little during
the past few runs. Both models as well as the DGEX and Canadian
models all show this trough and its cooler temperatures and
moisture enhancing shower/storm chances across the cwa. Best
chance for measurable precip appears to be late Thursday
afternoon/evening over and along the Front Range and Palmer
Divide...and on the northeast plains Friday afternoon with the
passage of a cold front. Would not rule out a few pockets of heavy
rainfall with rising precipitable water with this system.
By Saturday...models show this trough and front moving out across
the Great Plains and a shortwave upper ridge building over the
state...bring warmer and drier conditions to the area. This
trend continues Sunday with southerly flow and an amplifying
ridge.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 748 PM MDT Sun May 22 2016
An outflow bndry fm high based showers is moving south quickly
and should reach dia by 0215Z. Winds gusts to 30 mph fm the north
will occur for a brief period of time but should decrease by 03z.
A few high based showers/storms are developing behind the bndry
so may have to mention vcts at dia until 03z if they continue to
dvlp southward.
Overnight winds will become more ely by midnight and then sely
by 09z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...RPK
SHORT TERM...Dankers
LONG TERM...Baker
AVIATION...RPK
Area Forecast Discussion
National Weather Service Pueblo CO
344 PM MDT TUE MAY 24 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 343 PM MDT Tue May 24 2016
...Isolated storms mainly north and east of southern Colorado...
The interaction of southeast winds feeding into the Denver Cyclone
and an upper level disturbance will trigger the main show this
afternoon. Southern Colorado will generally be too far south for
much action. Still some threat of isolated storms, possibly severe,
over the far eastern plains into early evening. Also, maybe an
isolated storm or two over the central mountains or Pikes Peak
Region. The primary threats from any of these storms will be
lightning and wind gusts to around 50 mph. However, there is the
small possibility of a severe storm over the far southeast plains,
primarily Kiowa, Bent or Prowers Counties. If a storm manages to
gain enough strength out that way, 1 inch diameter hail and wind
gusts to 60 mph will be possibilities.
Things should wind down pretty quickly after sunset this evening.
Wednesday looks mostly sunny and warm with little chance for
precipitation across the area. Afternoon highs should be near
average over the west and about 5 or so degrees above average
over the east.
The combination of gusty winds and low humidities will make for
critical fire weather conditions Wednesday afternoon but with the
greenup underway, no fire weather highlights at this time.
Regardless, caution is advised.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 343 PM MDT Tue May 24 2016
Primary meteorological issues for the CWA continue to be
temperatures, POPS/QPF amounts and the potential for strong to
severe thunderstorms at times.
Relatively dry southwesterly upper flow is expected to continue
over the forecast district into Wednesday evening with a more
active active meteorological pattern then expected to develop.
A closed upper low, located over west-central Arizona at 06Z
Thursday is projected to enter the 4-Corners region by 18Z
Thursday and then move across southern Colorado Friday, before
shifting east of the forecast district Friday night. In addition,
northerly to northeasterly surface surges are expected to move
across the area during the late week period.
Increased precipitation chances are expected from Thursday into
Friday in combination with the potential for strong to potentially
severe thunderstorms at times. Also, locally heavy rainfall will
also be possible during this time-frame. In addition, even some
higher terrain accumulating snow is anticipated, primarily from
later Thursday into Friday.
It still appears that a return to somewhat drier and warmer
conditions with generally isolated to scattered showers and
thunderstorms at times should be noted over many locations from
Memorial Day weekend into early next week as zonal to
southwesterly upper flow combines with the daily orographic
heating cycle, available atmospheric moisture and generally weak
upper disturbances at times. In addition, the potential for some
strong to potentially severe thunderstorms will be possible during
this time-frame, favoring eastern portions of the forecast
district.
Coolest temperatures during the longer term should be noted from
Thursday into Friday night, while warmest conditions should
prevail from Sunday into next Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 343 PM MDT Tue May 24 2016
Generally VFR expected across flight area next 24 hours under dry
and warm southwest flow aloft. However, there could be a spotty late
day or early evening shower or storm over the central mountains, the
Pikes Peak Region, along the Palmer Divide or over the far southeast
plains. The primary concern with any such storm would be lightning
and erratic downburst winds gusts to around 50 mph. However, a storm
over the far southeast plains could be a bit stronger. The window
for convection will run until about 03Z. Tomorrow looks mostly sunny
and warm with little chance for precipitation across the flight
area. The KCOS...KPUB and KALS TAF sites should all remain VFR
over the next 24 hours.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
1104 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 337 AM MDT Tue May 24 2016
...Warm and generally dry today...
Currently...low clouds are slowly expanding over the NE portion of
the CWA, and will likely continue to expand over the next few hours.
Areas of stratus will be most likely east of I-25 and north of Hwy
50. Low cloud deck should dissipate by mid morning, leaving mostly
sunny skies for the rest of today.
Main concern today will be the potential for strong to severe storms
over a small portion of the CWA, generally from Eastern Pueblo
County eastward to the KS border, and north of Hgwy 50. A surface
low will depend to about 996 mb this afternoon, setting up over
Bent and Prowers counties late in the day. North of the surface low,
surface winds will back strongly in a moisture rich environment with
CAPE approaching 3000 J/kg. Along with bulk shear in the 40-50 kt
range, this environment will be conducive to supercell
development. The surface low will shift northward by late
afternoon, leaving only a short window of opportunity for storms
to develop in our area. The NAM keeps the area free of storms,
while other high res solutions such as the ARW and NMM develop a
couple cells in this area late in the afternoon. Given the
potential, will introduce low POPs for this period. The severe
threat looks mainly confined to Kiowa County, but could shift to
include more or less of our CWA depending on the surface low
development. Since all modes of severe wx would be possible with
any storms that form, will have to watch for this potential later
this afternoon.
Otherwise, just a warm and breezy day, with temps in the mid to
upper 80s over the plains and south to southwest winds gusting in
the 20-30 kt range this afternoon. Dry SW flow will increase by
evening, leaving us with a clear night with seasonal temps in the
40s for the plains and 30s for the high valleys. Rose
.LONG TERM...(Wednesday through Monday)
Issued at 337 AM MDT Tue May 24 2016
Trough over the western conus will keep the pattern potentially
active over the region during this period. The most active day is
expected to be Thursday as strong to severe storms may occur.
Friday should be cool with quite a few showers/-tsra over the
region.
Wednesday...
Primary trough will still be just offshore of the Calif coast and
will be moving inland during this day. Mid lvl low over the region
will be southwesterly with a weak shortwave ridge moving over the
area. Expect mainly dry warm weather will only an isold tsra over
the higher terrain...and possibly a high based tsra over the
palmer dvd.
Thursday...
Trough moves inland and should be located over the Las Vegas region
by 12z Thu. system will develop into a broad closed low as it moves
towards the region during the day. A cool front will move across the
plains during early morning Thursday and upslope flow will commence
by midday over the area. Given the closed low moving towards the
area...modest mid lvl southwesterly flow aloft and upslope.
flow...conditions will be come favorable for rotating convection on
the plains...with the best chance attm n of highway 50.
As the low moves over the region Thu night...wrap around precip
is forecast to develop along the I25 corridor....especially from
Walsenburg northward. Scattered showers will likely continue
through the night across most of the region.
Friday...
Cooler weather is likely this day. Upper closed low will likely be in
the vicinity of the KS/CO/NE border by midday...with northwesterly
flow over the region. Given the rather cold air aloft...we should
see lots of showers and weaker tsra over the region...especially
during the afternoon.
Saturday...
Weak mid lvl ridge will move over the region during this day. Expect
mainly isold tsra during the afternoon...mainly over the higher
terrain.
Sunday...
Weak southwesterly flow aloft will once again redevelop over the
region as another pacific wx system moves towards the region. Weak
cyclogenesis is forecast to develop over the raton mesa and this
will allow upslope to develop over the plains. if pattern
develops...weak favorable deep shear will develop and we may see a
strong storm or two over the plains. Scattered tsra are likely
over the mtns on this day.
Memorial Day into early next week...
Broad trough will continue over the west. However...models disagree
on intensity of this trough. GFS is deeper with the trough while
EC is more progressive and not as amplified. if GFS
verifies...then area will see a better chance of precip while the
EC pattern will promote more of a dry pattern. For what it is
worth...the GFS spaghetti ensemble plots show a considerable
amount of variability in the troughs location/intensity... so
confidence in forecast is low attm for early next week. /Hodanish
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1044 AM MDT Tue May 24 2016
Generally VFR expected across flight area next 24 hours under dry
and warm southwest flow aloft. However, there could be some spotty
late afternoon and early evening showers or storms over and near
the mountains, just north of the Palmer Divide and over the far
southeast plains. The primary concerns with any such storms would
be lightning and erratic downburst winds gusts to around 50 mph.
Window for convection would be about 20Z to 03Z. KCOS...KPUB and
KALS TAF sites should remain VFR next 24 hours.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...HODANISH
AVIATION...LW
[top]
Area Forecast Discussion
National Weather Service Grand Junction CO
1057 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today through Wednesday)
Issued at 316 AM MDT Tue May 24 2016
Eastern UT and western CO will remain under moderate southwest
flow aloft ahead of another low pressure system that covers the
states to the west and north. Today will be drier and warmer and
Wednesday will be drier than previous thought as the western
troughy pattern will be slow to move east. Two circulation
centers, the first retrograding from central Canada into central
and western Montana, will come into phase as the second low
travels along the west coast to southern California by Wednesday
morning. This process appears to slow the easterly movement of the
broader long wave trough comprised of the two smaller lows. This
leaves the forecast area under and drier southwest flow and allows
daytime temperatures today and Wednesday to rise to seasonal
normals.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 330 PM MDT Mon May 23 2016
Wednesday night the southern trough will move out of southern CA
into western AZ and it weakens as it lifts NE into Utah and
Arizona Thursday morning. Chances of showers increase on Thursday
as its associated cold front work through the area. Moisture and
instability are limited with only weak cold advection aloft so did
not force POPs much above guidance for now.
Friday an unsettled NW flow aloft brings another round of late day
showers and isolated thunderstorms for all but SE Utah. After a
cool Thursday-Friday a warming trend begins. The next upper low
drops in from British Columbia over the weekend backing the flow
to SW again. This trough deepens along the California coast early
next week and may pass through this forecast area on June 2nd or
so.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1057 AM MDT Tue May 24 2016
Mid and high level cloud cover at or above 120kft agl is keeping
VFR conditions in place at forecast terminals late this morning.
This flight level rule will persist over the next 24 hours.
Afternoon instability will lead to another round of isolated
thunderstorm development through sunset. Probabilities of a storm
impacting the TAF sites is too low to place in forecast attm.
General wind gusts exceeding 25 mph will also be possible through
the mid to late afternoon hours which could enhance outflow winds
from thunderstorms with gusts reaching up to 50 mph near some
storms.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...CC
LONG TERM...JOE
AVIATION...TGJT
[top]
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1050 AM MDT TUE MAY 24 2016
.UPDATE...
Issued at 1050 AM MDT Tue May 24 2016
Slightly more moisture is currently being observed across the
eastern plains than forecast at this time. With good southeasterly
flow, this moisture is expected to continue to advect toward the
front range urban corridor late this morning. Cumulus clouds on
webcams are already experiencing growth and latest hi-res models
are starting to fire convection off by 19z around the Denver
area. Forecast soundings are showing excellent shear with CAPEs in
the 2400-3500 J/kg over the area from Denver north and east to
Wyoming/Nebraska/Kansas borders. Will continue to expect scattered
to numerous thunderstorms to push northeast today with isolated to
scattered severe storms possible. Main threats will be large hail,
strong damaging outflow winds and lightning, but tornados will be
possible as well. Timing of the severe weather potential will
remain around 2-5pm for the urban corridor (mainly Denver and
north) and 3-9pm for the northeastern plains.
&&
.SHORT TERM...(Today and tonight)
Issued at 320 AM MDT Tue May 24 2016
Southwest flow aloft will prevail around an upper level trough
over California. A weak short wave trough embedded in the flow
aloft and a surface low will move across the state today.
Southerly flow around the low will bring drier air to southern
Colorado while southeast to east winds farther north will
transport moisture into northeast Colorado. Expect an east/west
boundary/dry line to set up this afternoon. The southerly flow
will also likely cause a Denver Cyclone to form. As the airmass
moistens...low clouds are expected to spread across parts of
northeast Colorado early this morning. They may be slow to burn
off and thus lowered highs a few degrees, especially across
northern parts of northeast Colorado.
The HiRes models are in general agreement that convection will
initiate over/near the Denver metro area 2-3pm. Likely due to
convergence along the Denver Cyclone and the east/west boundary.
Storms will spread northeast through afternoon and evening hours.
Greatest threat for severe thunderstorms will be northeast of the
Denver area where CAPES will be 1000-2500 J/kg. Main threat will
be large hail. Damaging winds and a couple of tornadoes will also
be possible.
Drier air will spread across northeast Colorado overnight.
Convection is expected to exit the area by midnight and by
Wednesday morning mostly clear skies will prevail.
.LONG TERM...(Wednesday through Monday)
Issued at 320 AM MDT Tue May 24 2016
On Wednesday...the upper level trough will remain to the west with
a dry southwesterly flow aloft over north central and northeast
CO. The models show weak subsidence over the cwa through the day
...with the best low level moisture flushed out to the east into
western NE and northwestern KS. The models generate some QPF in
the aftn but it is mainly over the mountains. Wednesday night...
...a little surge is progged to push into the northeast corner of
CO. This boundary could act as a focus for nocturnal tstms around
06Z Wednesday night. Thursday through Friday...it will be cooler
and wetter across the cwa. The models have the next system near
the Four Corners region by 18z Thursday then move into western
NE/KS by Friday evening. As a result...there appears to be a
prolonged period of light to moderate rainfall over the region. The
models all show moderate QG ascent over the cwa Thursday
aftn/evng...with decreasing QG ascent late Thursday night and
Friday as the trough starts to shift to the east of CO. Highest
pops will be Thursday night...but still a good chance of showers
especially from the Front Range Foothills eastward on Friday.
There is a marginal threat for severe thunderstorms closer to the
KS border on Thursday aftn. It will also be a little cooler and
this may help to minimize the threat of severe thunderstorms. Over
the weekend...a drier westerly flow aloft will be over the state
on Saturday. It will be warmer with enough moisture around to keep
a slight chance of aftn/evng thunderstorms both days. By Sunday...
another trough in the Pacific Northwest will produce a southwesterly
flow aloft over CO.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1050 AM MDT Tue May 24 2016
Southeast winds will continue to produce scattered low clouds of
3000-5000 ft across eastern Colorado for the next hour or two.
Scattered thunderstorms are then expected to form after 19z. The
best chance for thunderstorms in the Denver area will be 19-23Z.
Wind gusts to 40 knots, hail, and heavy rain will be possible with
the thunderstorms. Drier air will move into the area after 00z and
bring mostly clear skies by 06z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Meier
LONG TERM...Cooper
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Pueblo CO
342 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 337 AM MDT Tue May 24 2016
...Warm and generally dry today...
Currently...low clouds are slowly expanding over the NE portion of
the CWA, and will likely continue to expand over the next few hours.
Areas of stratus will be most likely east of I-25 and north of Hwy
50. Low cloud deck should dissipate by mid morning, leaving mostly
sunny skies for the rest of today.
Main concern today will be the potential for strong to severe storms
over a small portion of the CWA, generally from Eastern Pueblo
County eastward to the KS border, and north of Hgwy 50. A surface
low will depend to about 996 mb this afternoon, setting up over
Bent and Prowers counties late in the day. North of the surface low,
surface winds will back strongly in a moisture rich environment with
CAPE approaching 3000 J/kg. Along with bulk shear in the 40-50 kt
range, this environment will be conducive to supercell development.
The surface low will shift northward by late afternoon, leaving only
a short window of opportunity for storms to develop in our area. The
NAM keeps the area free of storms, while other high res solutions
such as the ARW and NMM develop a couple cells in this area late in
the afternoon. Given the potential, will introduce low POPs for this
period. The severe threat looks mainly confined to Kiowa County, but
could shift to include more or less of our CWA depending on the
surface low development. Since all modes of severe wx would be
possible with any storms that form, will have to watch for this
potential later this afternoon.
Otherwise, just a warm and breezy day, with temps in the mid to
upper 80s over the plains and south to southwest winds gusting in
the 20-30 kt range this afternoon. Dry SW flow will increase by
evening, leaving us with a clear night with seasonal temps in the
40s for the plains and 30s for the high valleys. Rose
.LONG TERM...(Wednesday through Monday)
Issued at 337 AM MDT Tue May 24 2016
Troughieness over the western conus will keep the pattern potentially
active over the region during this period. The most active day is
expected to be Thursday as strong to severe storms may occur.
Friday should be cool with quite a few showers/-tsra over the
region.
Wednesday...
Primary trough will still be just offshore of the Calif coast and
will be moving inland during this day. Mid lvl low over the region
will be southwesterly with a weak shortwave ridge moving over the
area. Expect mainly dry warm weather will only an isold tsra over
the higher trrn...and possibly a high based tsra over the palmer
dvd.
Thursday...
Trough moves inland and should be located over the Las Vegas region
by 12z Thu. system will develop into a broad closed low as it moves
towards the region during the day. A cool front will move across the
plains during early morning Thursday and upslope flow will commence
by midday over the area. Given the closed low moving towards the
area...modest mid lvl southwesterly flow aloft and upslope.
flow...conditions will be come favorable for rotating convection on
the plains...with the best chance attm n of highway 50.
As the low moves over the region Thu nite...wrap around precip is
fcst to develop along the I25 corridor....especially from Walsenburg
northward. Scattered showers will likely continue through the night
across most of the region.
Friday...
Cooler weather is likely this day. Upper closed low will likely be in
the vicinity of the KS/CO/NE border by midday...with northwesterly
flow over the region. Given the rather cold air aloft...we should
see lots of showers and weaker tsra over the region...especially
during the afternoon.
Saturday...
Weak mid lvl ridge will move over the region during this day. Expect
mainly isold tsra during the afternoon...mainly over the higher
trrn.
Sunday...
Weak southwesterly flow aloft will once again redevelop over the
region as another pacific wx system moves towards the region. Weak
cyclogenesis is fcst to develop over the raton mesa and this will
allow upslope to develop over the plains. if pattern develops...weak
favorable deep shear will develop and we may see a strong storm or
two over the plains. Scattered tsra are likely over the mtns on this
day.
Memorial Day into early next week...
Broad trough will continue over the west. However...models disagree
on intensity of this trough. GFS is deeper with the troughieness
while EC is more progressive and not as amplified. if GFS
verifies...then area will see a better chance of precip while the EC
pattern will promote more of a dry pattern. FWIW...GFS spaghetti
ensemble plots show a considerable amount of variability in the
troughs location/intensity... so confidence in fcst is low attm for
early next week. /Hodanish
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 337 AM MDT Tue May 24 2016
Main AVN concern will be low cigs this morning over portions of the
SE CO Plains, generally east of I-25 and N of hwy 50. This will most
likely affect KCOS, which could see some MVFR cigs until about 13Z-
15Z. Low clouds could potentially move into the KPUB vicinity, but
likelihood is too low ATTM to mention in the TAF. Otherwise, expect
VFR conditions for the next 24-30 hours and S-SW winds a bit breezy
this afternoon with gusts in the 20-30 kt range possible. A strong
to severe TS or two cannot be ruled out over the Plains, but any
storms will be well east of I-25 and most of the stronger convection
will remain in NE CO and KS. Rose
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...HODANISH
AVIATION...ROSE
Area Forecast Discussion
National Weather Service Denver/Boulder CO
320 AM MDT TUE MAY 24 2016
.SHORT TERM...(Today and tonight)
Issued at 320 AM MDT Tue May 24 2016
Southwest flow aloft will prevail around an upper level trough
over California. A weak short wave trough embedded in the flow
aloft and a surface low will move across the state today.
Southerly flow around the low will bring drier air to southern
Colorado while southeast to east winds farther north will
transport moisture into northeast Colorado. Expect an east/west
boundary/dry line to set up this afternoon. The southerly flow
will also likely cause a Denver Cyclone to form. As the airmass
moistens...low clouds are expected to spread across parts of
northeast Colorado early this morning. They may be slow to burn
off and thus lowered highs a few degrees, especially across
northern parts of northeast Colorado.
The HiRes models are in general agreement that convection will
initiate over/near the Denver metro area 2-3pm. Likely due to
convergence along the Denver Cyclone and the east/west boundary.
Storms will spread northeast through afternoon and evening hours.
Greatest threat for severe thunderstorms will be northeast of the
Denver area where CAPES will be 1000-2500 J/kg. Main threat will
be large hail. Damaging winds and a couple of tornadoes will also
be possible.
Drier air will spread across northeast Colorado overnight.
Convection is expected to exit the area by midnight and by
Wednesday morning mostly clear skies will prevail.
.LONG TERM...(Wednesday through Monday)
Issued at 320 AM MDT Tue May 24 2016
On Wednesday...the upper level trough will remain to the west with
a dry southwesterly flow aloft over north central and northeast
CO. The models show weak subsidence over the cwa through the day
...with the best low level moisture flushed out to the east into
western NE and northwestern KS. The models generate some QPF in
the aftn but it is mainly over the mountains. Wednesday night...
...a little surge is progged to push into the northeast corner of
CO. This boundary could act as a focus for nocturnal tstms around
06Z Wednesday night. Thursday through Friday...it will be cooler
and wetter across the cwa. The models have the next system near
the Four Corners region by 18z Thursday then move into western
NE/KS by Friday evening. As a result...there appears to be a
prolonged period of light to moderate rainfall over the region. The
models all show moderate QG ascent over the cwa Thursday
aftn/evng...with decreasing QG ascent late Thursday night and
Friday as the trough starts to shift to the east of CO. Highest
pops will be Thursday night...but still a good chance of showers
especially from the Front Range Foothills eastward on Friday.
There is a marginal threat for severe thunderstorms closer to the
KS border on Thursday aftn. It will also be a little cooler and
this may help to minimize the threat of severe thunderstorms. Over
the weekend...a drier westerly flow aloft will be over the state
on Saturday. It will be warmer with enough moisture around to keep
a slight chance of aftn/evng thunderstorms both days. By Sunday...
another trough in the Pacific Northwest will produce a southwesterly
flow aloft over CO.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 320 AM MDT Tue May 24 2016
Southeast winds will increase low level moisture and is expected
to produce low clouds across eastern Colorado. Ceilings of 1000 to
3000 feet are expected at the Denver airports from 11 to 15z, low
clouds may linger through the late morning, until 18z. Scattered
thunderstorms are expected to form after 20z. The best chance for
thunderstorms in the Denver area will be 20-23Z. Wind gusts to 40
knots, hail, and heavy rain will be possible with the
thunderstorms. Drier air will move into the area after 00z and
bring mostly clear skies by 06z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Meier
LONG TERM...Cooper
AVIATION...Meier
Area Forecast Discussion
National Weather Service Pueblo CO
1132 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1126 PM MDT Mon May 23 2016
KALS should see VFR conditions thru the next 24 HRS. KALS should
have gusty S to SW winds Tue afternoon and early evening. KCOS
and KPUB will have the potential for low stratus...mainly between
about 10Z and 15Z Tue...OTRW VFR conditions are expected. KCOS
and KPUB should see gusty S to SW winds in the afternoon and early
evening hours on Tue.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...28
Area Forecast Discussion
National Weather Service Grand Junction CO
1117 PM MDT MON MAY 23 2016
.SHORT TERM...(Tonight through Tuesday night)
Issued at 330 PM MDT Mon May 23 2016
A broad trough of low pressure remains over the Intermountain
West into next week bringing generally breezy, unsettled, and
cool conditions. Spokes of energy rotating through the trough from
SW to NE will drive our weather. This afternoon the first of
these spokes was lifting through NW Colorado. Scattered showers
north of I-70 will quickly end this evening. Tonight valley
inversions will allow temperatures to fall below normal and a
transient weak ridge will diminish the SW winds in the high
country.
Tuesday SW winds increase as the larger trough deepens along the
California coast. Moisture will be limited with only disorganized
forcing, so late-day showers will favor the northern-central
mountains. Overnight temperatures remain at or below normal.
.LONG TERM...(Wednesday through Monday)
Issued at 330 PM MDT Mon May 23 2016
Wednesday the trough works through California and weakens as it
moves into Utah-Arizona overnight. Chances of showers increase on
Thursday as its associated cold front work through the area.
Moisture and instability are limited with only weak cold advection
aloft so did not force POPs much above guidance for now.
Friday an unsettled NW flow aloft brings another round of late day
showers and isolated thunderstorms for all but SE Utah. After a
cool Thursday-Friday a warming trend begins. The next upper low
drops in from British Columbia over the weekend backing the flow
to SW again. This trough deepens along the California coast early
next week and may pass through this forecast area on June 2nd or
so.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1112 PM MDT Mon May 23 2016
Dry southwest flow will be in place across eastern Utah and
western Colorado for the next 24 hours. There is a less than 20
percent chance for late afternoon showers over the higher terrain
with gusty outflow winds to 40 mph the primary impact. Terminal
sites will remain VFR through the period.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...JOE
LONG TERM...JOE
AVIATION...JDC
Area Forecast Discussion
National Weather Service Pueblo CO
602 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 554 PM MDT Mon May 23 2016
Made a few minor adjustments to the forecast for this evening.
Isolated showers and thunderstorms will be possible through 8 pm
for the Central Mountains, Palmer Divide and far Southeastern
Plains. Lightning will be the primary threat. Expect any showers
or thunderstorms that do manage to develop to dissipate with sun
down with dry conditions prevailing overnight. Mozley
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 338 PM MDT Mon May 23 2016
...Slight chances for evening storms Pikes Peak Region and far
eastern plains...
A weak upper level shortwave is tracking across the northern
Colorado Rockies this afternoon. This system will act as a trigger
for a few afternoon and early evening showers and storms over the
central mountains and Pikes Peak Region. Surface airmass is pretty
dry, so not looking for a whole lot of precipitation but certainly
some lightning and gusty winds to about 50 mph possible. Also, so
local, wet, light snow accumulations possible above 10,000 feet.
Another area to watch for the possibility of a few evening showers
or storms is the far southeast plains, near the Kansas border. The
potential does not look great. But, there are boundary remnants out
there, that try to sharpen up a little during the evening. This
could act as an impetus for convection. The Storm Prediction Center
has the marginal risk for severe weather draped over Kiowa, Prowers,
Bent and norther Baca County. This looks pretty good based on where
the old boundary remnants should be. Primary threats at this point,
if anything goes, look like 1 inch diameter hail, 60 mph winds and
lightning. Overnight into Tuesday morning, there could be some low
cloud development across parts of the plains resulting from this
evening`s boundary and convective interactions. This would
primarily be over portions of Kiowa, Prowers and Bent Counties.
Tuesday, the severe weather threaten sharpens but also shifts mainly
off to the north and east of southeast Colorado. The Storm
Prediction Center has a slight and enhanced risk of severe weather
over the northeast Colorado plains, with the marginal risk area just
clipping northeast Kiowa County. If this holds, little severe
weather threat over southern Colorado Tuesday. However, if features
drift to the south just a tad, it could be a little busier down here
in the severe weather department. The latest models runs really
want to keep the threat over northern Colorado with just warm, dry
southwest flow over southern Colorado. So, for now, not looking to
volatile. Little chance of precipitation with temperatures ranging
from a few degrees above average over the west to 5 and 10 degrees
above average the east.
.LONG TERM...(Tuesday night through Monday)
Issued at 338 PM MDT Mon May 23 2016
Not many adjustments required from previous forecast reasoning
with main meteorological concerns continuing to be temperatures,
pops and the potential for strong to severe thunderstorms at
times.
It still appears that a generally dry southwesterly upper flow
pattern in combination with varying degrees of eastern Colorado
lee-side troughing/surface lows will continue over the forecast
district from Tuesday evening into Wednesday evening with
primarily higher terrain isolated afternoon and evening showers
and thunderstorms expected during this time-frame.
Then, more active meteorological conditions in the form of
increased shower and thunderstorm activity(some possibly strong to
severe at times) as well as cooler temperatures is anticipated
from Thursday into Friday evening as a combination of relatively
moist north-northeasterly surface flow interacts with a passing
closed upper low.
This closed upper low, initially centered over northwestern
Arizona at 06Z Thursday, shifts into the 4-Corners region by 18Z
Thursday and then moves across southern Colorado into Friday
before shifting east of the forecast district by later
Friday/Friday night.
A return to somewhat drier and warmer meteorological conditions
with basically isolated showers and thunderstorms at times are
projected over the majority of the forecast district during the weekend
with another increase in pops possible by Memorial Day Monday as
zonal to southwesterly upper flow interacts with available
atmospheric moisture, the daily topographic heating cycle and
generally weak upper disturbances at times. Once again, the
potential for some strong to potentially severe thunderstorms will
be possible during this time-frame, primarily over eastern
sections of the forecast district.
Finally, warmest maximum temperatures during the longer term are
anticipated Wednesday and then again Saturday and Sunday with
coolest conditions projected Thursday and Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 338 PM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area until about 03Z...with little chance of storms tomorrow. The
most likely area for these showers or storms would be across the
central mountains, the Pikes Peak Region and the far eastern plains.
These storms do not look all that intense but would pose threats of
lightning and erratic wind gusts to 50 mph. Storms right near the
eastern Colorado border could be stronger. Storms may produce local
MVFR, IFR or even LIFR flight conditions requiring circumnavigation
by pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...MOZLEY
Area Forecast Discussion
National Weather Service Denver/Boulder CO
305 PM MDT MON MAY 23 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM MDT Mon May 23 2016
A jet max that pushed into southwestern Colorado earlier today
continues to push northeast, firing off convection over the
forecast area this afternoon. A shortwave ridge will be pushing
overhead tonight, however convection will spread northeast for
the rest of the afternoon and evening as a theta-e ridge advects
into the area from the south. The chance of showers and
thunderstorms will mainly confine itself overnight over the far
northeastern corner of the state. Skies will be clearing overnight
with winds becoming light, but at this time am not expecting any
fog to form. Minimum temperatures will be right around average
for this time of year.
More thunderstorms are expected Tuesday as a fast moving shortwave
ejected from an upper trough over California pushes over the area.
At the same time, a surface low should push into central Colorado,
with southeasterly surface winds helping to advect in higher
theta-e values. CAPE values between 1000-3300 J/kg are progged,
with the highest values over the far northern to northeastern
plains. Shear and instability is enough to prompt SPC to cover the
northeastern plains with an Enhanced Risk of severe storms. Large
hail and strong damaging winds are likely from the stronger
storms, but cannot rule out a tornado forming with good turning in
the winds from the surface upwards. Temperatures will warm about 5
to 10 degrees over todays readings.
.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM MDT Mon May 23 2016
Models continue to indicate the passage of a couple of weak mid-
level instability axes/shortwave troughs over the forecast area
during the afternoon and evening hours Tuesday and Wednesday. The
stronger of these disturbances appears to pass over the area late
on Tuesday impacting mainly the northeast corner of the CWA
during the evening. Could see t-storms forming along a wind
shift/dry line which slowly translates northeast with the
shortwave during the evening. Best sfc based capes and instability
east of this boundary where gusty sely sfc winds continue to
advect in lower 60s wetbulb temps. A few storms may produce hail...
stg gusty winds and brief moderate to heavy rainfall rates. Cannot
rule out a severe storm east of a Briggsdale-to-Akron line. The
late Wednesday disturbance being carried along by strengthening
swly flow aloft appears weaker and not as moist. Yet may still see
isolated to widely scattered showers and t-storms produce gusty
winds and light to moderate rainfall over and along the Front
Range during the late afternoon and evening hours.
During the Thursday-Friday time period...the poorly organized long
wave upper trough over the Great Basin is still progged to migrate
eastward across the Rocky Mountain region during this period.
Models now in better agreement as they all show this open wave
trough bringing cooler air and a decent amount of moisture to the
state. Should see an increase in shower and t-storm coverage
both days. Thursday afternoon and evening appears to be the
optimum time for shower and t-storm development along and east of
the Front Range with the upper low passing to south and a moist post-
frontal low-level upslope flow on the plains. CAPES off interactive
soundings not terribly great due largely to cooler temps and
increasing cloud cover. However cannot rule out a couple of t-storms
producing locally heavy rainfall and hail. By Friday...models
show the CWA on the back side of the upper trough...but a weak
upr air disturbance swinging out of the nrn Colorado mtns and srn
Wyoming during the afternoon could generate additional showers and
perhaps a few t-storms. Although their intensity should not be
not as great as the day before. Temps Thursday and Friday expected
to drop 10 deg f or so from those on Wednesday.
Saturday through Monday...trough moves east and washes out over
the northern Great Basins placing the fcst area under a gentle
near zonal flow aloft on Saturday. Sunday and Monday the area
comes under the influence of a warmer south-southwesterly flow
with just a slight chance of heat driven afternoon and evening
t-storms each day.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 305 PM MDT Mon May 23 2016
VFR conditions are expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains.
Wind gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward light drainage
tonight. At this time, no widespread fog is expected, however
there could be some patchy areas along the South Platte River
valley. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...Kriederman
LONG TERM...Baker
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Denver/Boulder CO
144 PM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 139 PM MDT Mon May 23 2016
VFR conditions expected through Tuesday afternoon. Scattered
thunderstorms across the Denver area airports will last through
about 00z before the main activity pushes east over the plains. Wind
gusts to 30 knots and brief heavy rain are possible with the
storms over the urban corridor...with stronger winds and small
hail possible over the eastern plains. Easterly winds at 15 to 25
knots will become variable with the convection, then trend
northeasterly early this evening before trending toward drainage
tonight. More convective activity is expected tomorrow, especially
over the far northeastern plains where strong winds and hail are
expected.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Kriederman
Area Forecast Discussion
National Weather Service Pueblo CO
1106 AM MDT MON MAY 23 2016
.SHORT TERM...(Today and tonight)
Issued at 342 AM MDT Mon May 23 2016
Shallow cold front was dropping southward through the plains this
morning, bringing a shift to north winds and slightly higher
dewpoints to most areas along and east of I-25. Front looks like it
will become stationary near the NM border by mid-morning, before
lifting slowly back northward through the afternoon and evening as
surface pressure begins to fall in response to next upper wave
dropping south along the west coast. Models suggest some modest low
level moisture and instability may pool along and north of the
boundary by late afternoon, with perhaps some isolated tsra
developing along the palmer divide and near the ks border as weak
moisture convergence may be enough to generate convection. 0-6km
shear will be sufficient for a strong to severe storms if convection
can develop, although best chances for severe will likely stay just
north and east of the area where deeper instability lies. Central
mountains could also see a brief tsra or two as well, though again
coverage/intensity will be sparse/weak. Max temps will continue to
drift downward a few degrees, with most noticeable cooling over
the eastern plains behind the front. Overnight, any convection
will end quickly in the evening as strongest forcing continues to
stay just north and east of the region. By early Tue morning, cold
front will slosh back southward through the plains, with perhaps
enough low level moisture for some stratus along the KS border
toward sunrise.
.LONG TERM...(Tuesday through Sunday)
Issued at 342 AM MDT Mon May 23 2016
...Best chance of rain on Thursday...
Extended portion of the forecast still looks pretty tame, and models
are in good agreement through the end of the week and into the
weekend.
Tuesday should be the warmest day of the period, with highs likely
topping out in the mid to upper 80s for the Plains...and 60s to low
70s for the higher elevations. Could be a bit breezy in the
afternoon as SW winds in the 30-35 kt range mix down to the surface.
Best chance for storms late in the afternoon will be mainly over NE
CO...so have maintained nil POPs for most of the area. Risk for
severe storms could sneak into Kiowa County by late afternoon or
early eve...so could see a slight risk of severe once again near
the KS border. SW flow pattern continues on Wed with continued
warm conditions and low threat of convection. Best chance for any
precip will be over the Pikes Pk region and Upper Arkansas Valley.
Thursday morning, the upper low to our west will finally start
moving into our area...reaching the 4 Corners area by mid day.
This will bring an increased threat of showers and storms...first to
the central and SW mountains early in the day...and then to the I-25
corridor and Plains by afternoon, as the upper low moves eastward
into KS by Thu evening. Upslope flow, especially on the backside of
the upper circulation, will put the best chance of precip over the
eastern mountains and southern Front Range. Could potentially see
some localized heavy rainfall from this system so will have to keep
an eye out for that. Severe potential looks low over the area with
generally low CAPE...but the latest NAM does bring a ribbon of
higher CAPE into extreme eastern CO in the afternoon, so will
have to see how much low-level moisture can make its way into the
Plains. Latest guidance pushes the trough eastward fairly quickly on
Friday, so should see fewer showers and storms on Friday but still
on the cool side of climatology for afternoon temps. The pattern
reloads for the weekend as quasi-zonal flow transitions to SW flow
ahead of the next trough developing over the PacNW. Rose
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1023 AM MDT Mon May 23 2016
Mostly dry southwest flow aloft over flight area next 24 hours.
KCOS...KPUB and KALS TAF sites likely to remain dry and VFR.
Enough moisture and instability exists for a few spotty afternoon
and evening showers or thunderstorms over portions of the flight
area...primarily from 18Z to 03Z. The most likely area for these
showers or storms would be across the central mountains, the
Pikes Peak Region and the far eastern plains. These storms do not
look all that intense but would pose threats of lightning and
erratic wind gusts to 50 mph. Storms right near the eastern
Colorado border could be stronger. Storms may produce local MVFR,
IFR or even LIFR flight conditions requiring circumnavigation by
pilots.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...LW
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1029 AM MDT MON MAY 23 2016
.UPDATE...
Issued at 1029 AM MDT Mon May 23 2016
Convective clouds are increasing evidenced on satellite and
webcams across western and north-central Colorado this morning as
a jet max pushes into the western part of the state. Hi-res models
continue to initiate convection over Clear Creek and Gilpin
counties just before noon with it then spreading over the metro
areas early afternoon. No impressive CAPE values until later this
afternoon and evening over the eastern plains...and even
overnight. May see a few stronger storms out that way later on.
This is all covered with the current forecast...no need to adjust
much at this point.
Focus will be shifting to tomorrow afternoon`s convective
potential across the plains. CAPE values will be much higher,
between 1000 and as much as 3300 J/kg with good shear as well.
NWS SPC has the forecast area in a SLIGHT to ENHANCED risk for
severe storms.
&&
.SHORT TERM...(Today and tonight)
Issued at 431 AM MDT Mon May 23 2016
Still a few showers going on the tail of a jet streak that moved
across overnight. These should continue to slowly fade as they
drift northeast over the next few hours. Weather maker for today
is a stronger jet max that will lift from northern Arizona
northeast across the state today. This is generating banded high
clouds over the dry air in Utah now, and will bring lift to
northeastern Colorado as it passes this afternoon. The convective
environment today is not that great otherwise, with slightly
cooler temps and dew points in the 30s and 40s. Models all show
some convection with the jet streak, and it is probably enough to
overcome the weak capping, especially given a little bit of
easterly low level wind to aid convergence once storms get
started. It could wind up being a fairly early show, perhaps early
afternoon storms over the mountains and Denver, then toward the
eastern border by evening. Nice shear but not much CAPE, we will
be hard pressed to get more than about 800 j/kg. So maybe more
coverage of the storms but not a lot of strength. With the shear
there could be a low threat of marginal wind/hail over the
eastern portion of the plains, especially if the storms get
organized which they well could.
Clouds and showers should diminish quickly this evening. Prefer
the cooler GFS guidance which was a couple degrees cooler than our
previous forecast.
.LONG TERM...(Tuesday through Sunday)
Issued at 431 AM MDT Mon May 23 2016
For Tue and Wed...a relatively dry southwesterly flow aloft will
remain over Colorado ahead of an elongated upper trough over the
west...stretching frm central CA to MT Tue aftn. The southern
branch of the trough will make its way into southern NV by 00Z
Thu. The general trend both days will be for some tstms over the
mountains. a Denver cyclone Tue aftn will generate a boundary
that will act as a focus for tstms late Tue aftn/evng. best chc of
storm possibly severe will occur along and east of this boundary.
The NAM12 mdl shows the development of this pattern with the
strongest storms develping over central Weld County and lifting
to the northeast...which seems reasonable. Boundary layer CAPE
1000-2000 j/kg in this area...but some CIN as well. The NAM12
however shows a weak upper level disturbance which may help to
initiate tstms as it move across western and northern CO around
00Z Wed. On Wednesday...the flow will be more south/southwesterly
with more mid level subsidence under a short wave ridge. Sfc based
CAPE much lower so weaker tstms with lesser coverage as well. Thu
through Fri...the mdls still show the upper low approaching the
Four Corners region by 12z Thu...then lifting east/northeast
across CO. Best QG ascent in the mid levels will occur late
aftn/evng period which will help to produce a better chc of
showers/tstms over the entire cwa. A little cooler as well. the
GFS is about 6 hrs faster than the ECMWF regarding the passage of
the trough. By the weekend...the flow aloft drier and more
west/southwesterly. still tstms in the grids each aftn/evng but
mainly slgt chc pops.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 431 AM MDT Mon May 23 2016
VFR through tonight. Scattered thunderstorms are expected this
afternoon, with the main threat between 20z and 00z. Wind gusts to
40 knots and brief heavy rain are possible with the storms.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Kriederman
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Gimmestad
Area Forecast Discussion
National Weather Service Pueblo CO
1112 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1111 PM MDT Sun May 22 2016
A cold front will drop south across KCOS and KPUB through 06z
tonight with a northerly wind shift. Expect VFR conditions at all
three terminals through the next 24 hours. A few showers and
thunderstorms will be possible on Monday afternoon over the Palmer
Divide, and should remain north of KCOS through the evening.
Southerly winds will be gusty at all three terminals Monday
afternoon into the evening. Mozley
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
AVIATION...MOZLEY
Area Forecast Discussion
National Weather Service Grand Junction CO
1051 PM MDT SUN MAY 22 2016
.SHORT TERM...(This evening through Monday night)
Issued at 400 PM MDT Sun May 22 2016
H5 hand analysis at 12z had a dominant ridge over the central
CONUS with low pressure systems along both right and left coastal
states. Our CWA is squeezed between the ridge and west coast low
leaving moderately fast southwest flow aloft. So far cloud cover
is keeping much of the winds at bay in the valleys...but at
ridge tops and near showers gusty winds will continue into the
evening. Expect showers to quickly die off after sunset with loss
of heating and under subsidence behind a passing wave. Downstream
blocking over the eastern states over the next 24 to 36 hours
leaves low pressure over the northern rockies and intermountain
west. This leaves southwest flow in place across the region with
little moisture advection. The 1.5 PVU progs suggest another wave
passing through Monday afternoon during peak heating and will lead
to another round of convection over the higher terrain over the
northern mountains. Temperatures will be slightly warmer on Monday
but stay below normal for this time of May.
.LONG TERM...(Tuesday through Sunday)
Issued at 400 PM MDT Sun May 22 2016
The downstream block will gradually break down by mid week and the
western trough will be allowed to traverse across the Rockies
Thursday. Wednesday will be a mirror of Tuesday with only isolated
afternoon convection anticipated in the afternoon. The passage of
the trough will bring an uptick to the convection Thursday which
will linger into Friday with cooler temperatures aloft aiding in
afternoon instability in northerly flow aloft. The next Pacific
system drops into the west Saturday and southerly flow return to
our CWA going into next weekend. At this time winds seem more of a
concern than precipitation. Temperatures remain below normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1043 PM MDT Sun May 22 2016
A weak cold front will continue to move slowly east out of the
forecast area tonight with winds diminishing overnight. Weaker
flow will return on Monday...however...breezy gusts are expected
at all TAF sites by the afternoon hours. Residual moisture and
instability will allow scattered afternoon showers and isolated
thunderstorms north of I-70 before diminishing by early evening.
This shower activity is not expected to impact airport operations.
&&
.GJT Watches/Warnings/Advisories...
CO...None.
UT...None.
&&
$$
SHORT TERM...15
LONG TERM...15
AVIATION...MPM
Area Forecast Discussion
National Weather Service Pueblo CO
800 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 759 PM MDT Sun May 22 2016
Updated forecast to remove pops along the KS/CO border for the
rest of the night. Thunderstorm activity remaining east of the
area. Also updated winds and temperatures to reflect current
conditions.
&&
.SHORT TERM...(This evening through Monday)
Issued at 310 PM MDT Sun May 22 2016
...Severe weather along and near the southeast Colorado border late
this afternoon into the evening...
Supercell thunderstorms will likely develop along and near a dryline
adjacent to the southeast Colorado border late this afternoon. A few
isolated supercells will be possible right along the border areas.
Among the threats from any supercells that develop will be hail over
an inch in diameter, wind gusts over 60 mph, tornadoes, lightning
and locally heavy rain.
The most likely area for development in southeast Colorado will be
over eastern Baca County and then possibly north across eastern
Prowers and eastern Kiowa Counties. High resolution model runs
throughout the day have been repeatedly hitting these areas as
initiation points. Although, they have been gradually nudging the
very first cells slightly farther east with each passing run. The
high resolution models have the first cells going up close to 4 pm
MDT.
Otherwise, not a whole lot to talk about through tonight. Rest of
forecast area should remain dry and mild. There is a shortwave
approaching from the northwest that could threaten a shower or storm
over the central mountains this evening. However, it probably won`t
be very successful producing any precipitation given dewpoints that
are in the teens up that way.
For Monday, a weak boundary will move south into the plains. For
the plains, this should cool things a bit and possibly act as a
trigger for some isolated afternoon convection. In addition, the
central mountain areas, along the Continental Divide, will see a
chance for afternoon showers and thunderstorms as shortwave energy
moves through that region. Elsewhere, another dry and warm day
pretty similar to today.
.LONG TERM...(Monday night through Sunday)
Issued at 310 PM MDT Sun May 22 2016
A relatively tame meteorological pattern is anticipated during
the longer term with highest potential of widespread precipitation
expected from Thursday into Friday night as next system impacts
the forecast district. At this time, primary longer term
meteorological issues appear to be pops, temperatures and gusty
winds at times.
Initially, a basically dry southwesterly upper flow pattern in
combination with varying degrees of eastern Colorado lee-side
troughing/surface lows should be noted over the CWA from Monday
night into Wednesday night with isolated primarily afternoon and
evening higher terrain showers and thunderstorms anticipated
during this time-frame.
Meteorological conditions then become more active in the form of
increased shower and thunderstorm activity and cooler temperatures
from Thursday into Friday night as combination of relatively
moist north-northeasterly surface surges interacts with a closed
upper low initially located over northern Arizona at 06Z Thursday
which shifts into the 4-Corners region by Thursday morning and
then moves across southern Colorado by Friday morning before
shifting east of the forecast district by later Friday.
Then, a return to drier and warmer meteorological conditions(although
generally isolated showers and thunderstorms will still be
possible) are projected over the majority of the forecast district
by next weekend as zonal to southwesterly upper flow returns to
southern Colorado.
Finally, the highest potential for gusty gradient winds are
expected from Monday night into Tuesday night and then again by
later Thursday while warmest conditions during the longer term
should be experienced from Tuesday into Wednesday and then again
by next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 310 PM MDT Sun May 22 2016
Dry southwest flow will result in VFR over most of the flight area
for most of the forecast period. The far eastern plains, along the
eastern border, may see exception to this for a brief period late
this afternoon into the evening as storms fire along a dryline in
this vicinity. Pilots may have to navigate dryline storms in this
area...generally 22z-02z. KCOS...KPUB and KALS TAF sites should
remain VFR next 24 hours.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Stark
Area Forecast Discussion
National Weather Service Denver/Boulder CO
756 PM MDT SUN MAY 22 2016
.UPDATE...
Issued at 748 PM MDT Sun May 22 2016
Sct high based showers and a few storms will move across the nern
plains thru midnight and then should end shortly thereafter as a
disturbance moves quickly across.
&&
.SHORT TERM...(This evening through Monday)
Issued at 345 PM MDT Sun May 22 2016
Have seen a few showers develop over Larimer County over the past
couple hours, with additional showers expected over the next few
hours. A short wave seems to be embedded in the prevailing
southwest flow which is producing the shower activity across
northwest Colorado and the northern mountains. The HRRR and RAP
models indicate that a band of shower activity related to this
short wave will develop on the plains after 02z. The I-25 corridor
should remain dry, but areast to the east of Fort Morgan should
see an hour or so of shower activity between 02z and 06z. Showers
will move out of the state by 06z with clearing skies overnight. A
weak surge of northerly winds across the plains will follow the
passage of the evening shower activity.
Additional cooling is expected tomorrow as weak northerly flow
continues. More thunderstorm activity is expected over the
mountains tomorrow afternoon as the state remains under southwest
flow aloft and an upper jet moves over the state, bringing a bit
more dynamic forcing than we have had the past couple days. Late
in the afternoon showers are then expected to spread out onto the
plains.
.LONG TERM...(Monday night through Sunday)
Issued at 345 PM MDT Sun May 22 2016
A cross CONUS blocking trough-ridge-trough pattern keeps a warm
and relatively dry swly flow over Colorado through mid-week.
Models show a couple of weak mid-level pertabations carried along
in this flow and passing over nern portions of the cwa Monday
evening and again Tuesday afternoon and early evening. Storms
forming on a wind shift line just east of the I-25 corridor is
forecast to shift northeast across weld...Adams and Morgan
counties Monday evening. Sfc based capes and instability may be
sufficient to support a few strong storms capable of small hail...
stg gusty winds and brief heavy rainfall. This storm area will
shift east-northeast with the shortwave passing through the nern
corner of the state during the mid to late evening hours. Models
indicate 3-hour qpf amounts in the 0-20-0.30 inch range out there.
The late Tuesday shortwave appears a bit weaker and farther
north with more of an impact on the northern Front Range and
northern I-25 corridor around Ft. Collins. Brief rainfall land
gusty winds probably main output from these high based cells.
Wednesday looks drier with strong mid-level subsidence..and temps
generally around average with a downslope flow off the Front
Range. Strong diabatic heating should still manage to generate a
few late day showers/t-storms over the high terrain.
Thursday-Friday time period...open wave upper trough passing over
the Great Basin is still progged to makes slow eastward progress
across Colorado during the period. GFS has come into closer
agreement with the European model which has changed little during
the past few runs. Both models as well as the DGEX and Canadian
models all show this trough and its cooler temperatures and
moisture enhancing shower/storm chances across the cwa. Best
chance for measurable precip appears to be late Thursday
afternoon/evening over and along the Front Range and Palmer
Divide...and on the northeast plains Friday afternoon with the
passage of a cold front. Would not rule out a few pockets of heavy
rainfall with rising precipitable water with this system.
By Saturday...models show this trough and front moving out across
the Great Plains and a shortwave upper ridge building over the
state...bring warmer and drier conditions to the area. This
trend continues Sunday with southerly flow and an amplifying
ridge.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 748 PM MDT Sun May 22 2016
An outflow bndry fm high based showers is moving south quickly
and should reach dia by 0215Z. Winds gusts to 30 mph fm the north
will occur for a brief period of time but should decrease by 03z.
A few high based showers/storms are developing behind the bndry
so may have to mention vcts at dia until 03z if they continue to
dvlp southward.
Overnight winds will become more ely by midnight and then sely
by 09z.
&&
.BOU Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...RPK
SHORT TERM...Dankers
LONG TERM...Baker
AVIATION...RPK
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
517 PM CDT TUE MAY 24 2016
.UPDATE...
Issued at 517 PM CDT Tue May 24 2016
Quick update to expand/move up the chance of showers over western
ND from now through the early evening in response to the showers
developing out of the cumulus field in southwestern ND through 22
UTC. We have a slight chance of thunderstorms expanding northward
with time, too, but so far the dry boundary layer is tending to
minimize instability, updraft depth, and thus lightning chances.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 240 PM CDT Tue May 24 2016
Thunderstorm chances highlight the short term.
An upper level low currently located over southern Saskatchewan
will keep the region in southwest cyclonic flow. Most of western
and central North Dakota will remain dry through the afternoon,
but precipitation chances will increase through the late afternoon
and evening hours from west to east as a surface trough and
associated upper level short wave approaches from Montana.
Tonight, showers and some thunderstorms will develop in the
southwest and spread east overnight. Any thunderstorms that
develop will remain sub severe with modest CAPE and shear
forecast.
Wednesday, a more potent shortwave and surface low will approach
the Dakotas as the upper low approaches, bringing widespread rain
and scattered thunderstorms. The 12z NAM and GFS iterations show
more instability than previously forecast. If these solutions were
to verify, potentially anywhere from 1000 J/KG to 2500 J/KG of
MLCAPE will be in place by 21z, along a line from near Bismarck to
Jamestown and south to the state border. This instability will be
collocated with deep layer shear values of 25-35 knots. These
parameters would suggest a conditional severe weather threat in
south central and southeast North Dakota. However, quite a bit of
uncertainty remains about how much destabilization will actually
occur. Widespread precipitation is likely over the area early
Wednesday, potentially limiting daytime heating. If we can get
some breaks in the clouds, then some storms could produce some
marginally severe hail and winds. SPC has placed parts of south
central and southeastern North Dakota in a marginal risk of severe
weather, which matches up well with our current thinking. Clusters
of multicell or marginal supercell structures seem to be the most
likely storm modes.
Overnight Wednesday, rain chances will continue on the back side
of the surface low.
.LONG TERM...(Thursday through Tuesday)
Issued at 240 PM CDT Tue May 24 2016
Persistant southwesterly flow remains through the period with a
variety of short waves sliding through the area. Models are having
a tough time timing out the individual waves, so most periods will
have a broad-brushed chance for showers and thunderstorms.
Temperatures will remain near to slightly above average.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1242 PM CDT Tue May 24 2016
VFR conditions and generally light southwest winds will dominate
the first part of the forecast period. As we turn to late
afternoon and the early evening hours...chances of showers and
thunderstorms will begin to increase from west to east and
continue through the overnight hours and Wednesday. Periods of
MVFR ceilings/visibilities and gustier winds can be expected in
heavier showers or thunderstorms.
&&
.BIS Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...ZH
LONG TERM...JJS
AVIATION...ZH
Area Forecast Discussion
National Weather Service Bismarck ND
330 PM CDT TUE MAY 24 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 240 PM CDT Tue May 24 2016
Thunderstorm chances highlight the short term.
An upper level low currently located over southern Saskatchewan
will keep the region in southwest cyclonic flow. Most of western
and central North Dakota will remain dry through the afternoon,
but precipitation chances will increase through the late afternoon
and evening hours from west to east as a surface trough and
associated upper level short wave approaches from Montana.
Tonight, showers and some thunderstorms will develop in the
southwest and spread east overnight. Any thunderstorms that
develop will remain sub severe with modest CAPE and shear
forecast.
Wednesday, a more potent shortwave and surface low will approach
the Dakotas as the upper low approaches, bringing widespread rain
and scattered thunderstorms. The 12z NAM and GFS iterations show
more instability than previously forecast. If these solutions were
to verify, potentially anywhere from 1000 J/KG to 2500 J/KG of
MLCAPE will be in place by 21z, along a line from near Bismarck to
Jamestown and south to the state border. This instability will be
collocated with deep layer shear values of 25-35 knots. These
parameters would suggest a conditional severe weather threat in
south central and southeast North Dakota. However, quite a bit of
uncertainty remains about how much destabilization will actually
occur. Widespread precipitation is likely over the area early
Wednesday, potentially limiting daytime heating. If we can get
some breaks in the clouds, then some storms could produce some
marginally severe hail and winds. SPC has placed parts of south
central and southeastern North Dakota in a marginal risk of severe
weather, which matches up well with our current thinking. Clusters
of multicell or marginal supercell structures seem to be the most
likely storm modes.
Overnight Wednesday, rain chances will continue on the back side
of the surface low.
.LONG TERM...(Thursday through Tuesday)
Issued at 240 PM CDT Tue May 24 2016
Persistant southwesterly flow remains through the period with a
variety of short waves sliding through the area. Models are having
a tough time timing out the individual waves, so most periods will
have a broad-brushed chance for showers and thunderstorms.
Temperatures will remain near to slightly above average.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1242 PM CDT Tue May 24 2016
VFR conditions and generally light southwest winds will dominate
the first part of the forecast period. As we turn to late
afternoon and the early evening hours...chances of showers and
thunderstorms will begin to increase from west to east and
continue through the overnight hours and Wednesday. Periods of
MVFR ceilings/visibilities and gustier winds can be expected in
heavier showers or thunderstorms.
&&
.BIS Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...ZH
LONG TERM...JJS
AVIATION...ZH
[top]
Area Forecast Discussion
National Weather Service Grand Forks ND
258 PM CDT TUE MAY 24 2016
.SHORT TERM...(This evening through Wednesday night)
Issued at 255 PM CDT Tue May 24 2016
Main impacts through the short term will be next rain event
Wednesday-Wednesday night. Models in better agreement through
Wednesday with biggest differences in rain potential/placement in
later periods where guidance is all over the place.
Uncertainty continues with TSRA potential remainder of afternoon
into the evening. Surface wind field remains weak with minimal
upper support. There is modest instability/cape and no cap in
place over all but DVL Basin. Cu fields have been developing from
far SE ND into west central and northern MN so have some low pops
in this region as echoes begin to develop. Expect what ever
develops will weaken with loss of heating. Later tonight models
slower in lifting rain band northward with next wave so trimmed
back pops until closer to daybreak. Minimum temperatures should be
similar to last night.
More significant short wave and associated surface low will lift
NE Wednesday into the FA. Arcing band of shra/TSRA will lift
northward through the FA. Enough instability/cape and shear along
with low level convergence for severe storm potential. Feel there
will be enough clouds to hold temperatures into the 70s.
Best rain potential will shift into the northern FA Wednesday
night as low and wave lift north.
.LONG TERM...(Thursday through Tuesday)
Issued at 255 PM CDT Tue May 24 2016
Low will wobble around the northern forecast area Thursday for
continued rain potential, mainly across the north. Uncertain about
coverage at this point so held with chance pops.
Unsettled weather continues into Friday as southern stream upper
low begins to lift northward.
As southern stream upper low lifts northward into the N central US
rain chances will continue into the holiday weekend. The best
potential looks to be Saturday surrounded by lesser rain chances.
Does not look like a wash for the weekend and any breaks in the
clouds will allow temperatures to recover into mainly the 70s.
Conditions begin to improve Mon-Tue as remnants of the upper low
lifts ne. Temperatures to remain at or a bit above average.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1229 PM CDT Tue May 24 2016
Wind speeds look to remain pretty light until Wednesday morning,
when they will take on more of a steady SE direction. Not much for
clouds out there now, but expect at least some mid level clouds to
move in later tonight into early Wednesday. At this point will leave
any clouds in the VFR range. Not a lot of confidence in the pcpn
forecast so have left VCSH for most locations by Wednesday morning.
&&
.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&
$$
SHORT TERM...Voelker
LONG TERM...Voelker
AVIATION...Godon
Area Forecast Discussion
National Weather Service Bismarck ND
1246 PM CDT TUE MAY 24 2016
.UPDATE...
Issued at 1242 PM CDT Tue May 24 2016
The current forecast looks to be on track. Just blended the latest
observations to the current forecast. No major changes needed.
UPDATE Issued at 853 AM CDT Tue May 24 2016
Quiet weather remains this morning as upper low continues to spin
over southern Saskatchewan. Latest guidance continues to show the
possibility of some showers/weak thunderstorms developing over
northwest North Dakota in cyclonic flow around the low. Updates
have been sent.
UPDATE Issued at 610 AM CDT Tue May 24 2016
Quick update to blend to observed trends. Overall, the previous
forecast is well supported by the 06-10 UTC suites. Did introduce
afternoon PoPs across the far southwest given agreement among the
09 UTC HRRR/Experimental HRRR and the 00 UTC Hi-Res Window WRFs,
all suggesting possible isolated high based convective
development with a few leading impulses propagating northeast out
of the southwest CONUS low.
&&
.SHORT TERM...(Today and tonight)
Issued at 314 AM CDT Tue May 24 2016
Thunderstorm potential tonight highlights the short term
forecast.
Morning elevated convection across the James River Valley and far
south central North Dakota is expected to become focused across
the northern Red River Valley after 10 UTC per observed radar
trends through 08 UTC and the 06-07 UTC HRRR iterations.
Otherwise, a dry day is forecast with the exception of far
northwest North Dakota where diurnally driven scattered showers
and thunderstorms are possible in the vicinity of the upper level
low.
For tonight, the 00-06 UTC high resolution suites are in agreement
on convection developing this afternoon across eastern Wyoming in
association with the shortwave across the southwest CONUS this
morning. The consensus is for this convection to potentially
propagate northeast into western and central North Dakota through
the night aided by modest low level warm air advection and
moisture transport along and east of the inverted trough extending
into southwest North Dakota. Given marginal moisture and shear,
severe weather is not expected.
.LONG TERM...(Wednesday through Monday)
Issued at 314 AM CDT Tue May 24 2016
An active weather pattern through the weekend highlights the
extended forecast.
The 00 UTC global and ensemble suites are in agreement on
potential phasing Wednesday across the Northern Plains of the
upper level low across southern Saskatchewan this morning with the
aforementioned shortwave from the short term. This would favor
likely showers and thunderstorms. Will disregard the 00 UTC NAM
given likely convective feedback driving is anomalously deep low
Wednesday night into Thursday. Overall, cloud cover from morning
convection may limit insolation and instability build up through
the day and the severe convective threat. Thus, the SPC Day 2
Convective Outlook has a marginal risk only across the far
southern James River Valley of central North Dakota. The active
weather pattern with daily chances for showers and thunderstorms
continues into the weekend under favorable southwest flow aloft.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1242 PM CDT Tue May 24 2016
VFR conditions and generally light southwest winds will dominate
the first part of the forecast period. As we turn to late
afternoon and the early evening hours...chances of showers and
thunderstorms will begin to increase from west to east and
continue through the overnight hours and Wednesday. Periods of
MVFR ceilings/visibilities and gustier winds can be expected in
heavier showers or thunderstorms.
&&
.BIS Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...ZH
AVIATION...ZH