Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/23/16
AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
515 PM PDT SUN MAY 22 2016
.SYNOPSIS...
A weaker marine layer over the area will keep a partly cloudy
skies in place through Monday morning. 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...(SUN-WED)
A couple of troughs will move through the area the next couple
days, keeping temperatures 3-6 degrees below normal with varying
amounts of clouds but likely no precipitation. The cloud coverage
will be tricky to forecast as there is ample low lvl moisture but
very little inversion, much like this morning. In fact, additional
cooling with the trof will likely weaken the inversion even
further. So despite the little eddy spin up and moderate onshore
flow it may be difficult to generate anything more scattered to
broken cloud decks, especially south of Pt. Conception. Still,
there should be at least slightly better coverage tomorrow with
temperatures a degree or two cooler. Similar on Wednesday as the
second of the troughs comes through in the morning. If somehow we
can get a more solid low cloud deck there could be some spots of
drizzle during the morning hours.
As far as afternoon convection it doesn`t look particularly
favorable. LI`s are mostly positive and CAPE values are generally
under 200 j/kg. We should see some afternoon clouds over the mtns,
and many other areas as well, but just not seeing enough juice for
convection.
Thu should see at least a few degrees of warming as very weak
ridging develops. It remains to be seen if the warming aloft will
re-establish the marine lyr by that time.
.LONG TERM...(THU-SUN)
Fairly non-descript weather pattern through next weekend. The
little ridge late next week breaks down over the weekend allowing
another trough to move into CA. It will likely lead to slight
cooling, mainly across inland areas, and a slightly deeper marine
lyr and later clearing, but that`s about it.
&&
.AVIATION...23/0014Z.
At 23Z, the marine layer was around 1100 feet deep at KLAX. The
top of the inversion was around 1300 feet with a temperature
around 14 degrees Celsius.
North of Point Conception...Moderate confidence in the current
forecast. IFR to MVFR conditions will likely spread into terminals
between 06Z and 13Z. VFR conditions should redevelop between 16Z
and 17Z. An early arrival of MVFR conditions is possible on
Monday afternoon and evening.
South of Point Conception...Low confidence in the current
forecast. There is a chance of MVFR conditions at Los Angeles
County Terminals between 09Z and 16Z. Highest confidence exists
in the 13Z-16Z time period for the South Bay Terminals. There is a
chance of moderate low-level wind shear and turbulence at KSBA
through 08Z. An early arrival of MVFR conditions is possible on
Monday afternoon and evening.
KLAX...Low confidence in the current forecast. There is a 50
percent chance of MVFR conditions between 09Z and 16Z. After 22Z,
there is a 30 percent chance of MVFR conditions spreading in.
KBUR...Low confidence in the current forecast. There is a 20
percent chance of MVFR conditions between 12Z and 16Z.
&&
.MARINE...22/130 PM...
For the Outer Waters, good confidence in current forecast. High
confidence in SCA level winds continuing across the southern two
thirds through tonight. Gusty northwest winds will continue
through mid-week. So, there is a good chance that the SCA will
need to be extended and expanded to include the northern third
later this week.
For the Inner Waters, good confidence in current forecast.
Overall, winds and seas are expected to remain below SCA levels
through Tuesday night although there will likely be some local
gusts to 25 knots each afternoon and evening. From Wednesday
through Friday, the winds are expected to strengthen with a good
chance of SCA level winds for all the Inner Waters.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
For zone 645. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Monday For
zones 650-670-673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...MW
AVIATION...Hall
MARINE...RAT
SYNOPSIS...30
weather.gov/losangeles
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
304 PM MST SUN MAY 22 2016
.UPDATE...To Aviation Discussion...
&&
.SYNOPSIS...
A large region of low pressure will continue over the Western states
through next weekend. There will be day to day fluctuations in
temperatures and afternoon breeziness as the system waxes and wanes.
Overall though, temperatures will remain below normal and conditions
will remain dry.
&&
.DISCUSSION...
Rest of today through Thursday...
Afternoon temperatures are running a few degrees cooler than
yesterday afternoon over south- central AZ with less change over
southwest AZ and even a bit of warming over southeast CA. This is
roughly 10 degrees below normal. Winds are lighter than yesterday
especially over southeast CA. Looking at the large scale flow
pattern, there is a split flow at multiple points within the
Westerlies. At high latitudes there is Rex pattern of sorts at high
latitudes with upper lows being centered over far northeast Canada
and the Bering Sea and ridging in between (even extending far north
of Alaska). Within the undercutting flow, there is a series of ridges
and troughs over the northeast Pacific and North America. One of
those troughs is over the western states and within it are multiple
vort maxes/lobes. The models are in good agreement that the trough
will wobble and morph as these vort maxes move through and an East
Coast low exits. However, troughing will remain over the West. Thus,
temps remain below normal. In the Tuesday through Thursday time
frame, the southern end of a reconfigured trough moves
through. This will lead to breezy to locally windy conditions (most
noticeably on Tuesday) and a small dip in temperatures Wednesday and
Thursday. However, not seeing enough moisture for a precip threat
over our forecast area.
Friday through Sunday...
Heading into the weekend, some measure of western troughing will
persist though the magnitude/depth of the height anomalies are
somewhat uncertain. Regardless, there is no ensemble member
indicating any amount of ridging through the Southwest, so a
continuation of slightly below normal temperatures looks like a very
good bet.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Aftn/evening winds will generally hold west headings with some
gustiness up to 20kts. Some drift off west is likely (and has been
occurring on and off throughout the day) and VRB winds are possible
for short periods. Under continued clear skies, typical evening
southeasterly trends will develop ranging 7 to 9 kts.
Southeast California/Southwest Arizona including KIPL and KBLH...
KIPL winds will maintain some westerly component into the evening and
overnight hours, with another sundowner/breezy downslope westerlies
for the terminal this evening with some gusts in the 20kt range. Sfc
pressure gradient along the CO River Valley have not allowed any
dominant heading to settle in for KBLH, so will keep VRB in through
the evening before south-southwest winds develop for field overnight.
Clear skies to continue.
Aviation Discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Fire weather concerns throughout the period will be minimal.
Below normal temperatures and dry conditions can be anticipated each
day. Minimum humidity values will be between 10 to 15 percent with
good overnight recoveries. In addition, winds will range between 5
to 15 mph with stronger afternoon breezes.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...AJ/MO
AVIATION...Nolte
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service San Francisco Bay Area
228 PM PDT SUN MAY 22 2016
.SYNOPSIS...Cooler than normal conditions can be expected for much
of the week. In addition, there is a slight chance for showers
tomorrow and Tuesday especially for higher elevation locations.
&&
.DISCUSSION...as of 2:30 PM PDT Sunday...Just looking at
temperatures across our region today would not give you a clue at
the time of year. During many mid-to-late May days, inland spots
are well into the 80s with even 90s not out of the question.
Instead, almost all areas are in the 60s. This is due to the
overall pattern which has a cool nw flow aloft moving across our
CWA due to a system over the Northern Rockies plus an upper level
longwave trof.
Models show the general pattern will not change much through the week
with the overall flow forecast to remain from the nw while two
systems rotate through. Moisture will be very limited in our
region, however it will lead to some instability which will kick
off clouds plus even some spotty showers both Monday and Tuesday.
Thunderstorm remain an outside risk as well particularly tomorrow
afternoon as lifted values drop to around zero. Best chance for
that would be over far eastern parts of the CWA. Any rain that
falls should be light with less than 1/10" forecast. Due to the
pattern temperatures will stay mostly in the 60s to lower 70s
which would translate to as much as 10 degrees cooler than normal.
Currently do not see favorable conditions create weather related
hazards of note for the entire week.
&&
.AVIATION...as of 10:52 AM PDT Sunday...Low clouds prevail across
the area as a result of a very moist boundary layer. MVFR cigs
expected across area terminals this morning with clearing
anticipated after noon today. 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...MVFR cigs will prevail til 19Z-20Z 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 conditions will prevail through this
evening. Generally light onshore winds through forecast period.
&&
.MARINE...as of 02:30 PM PDT Sunday...A weakening trough of low
pressure situated over the Western U.S. will maintain light
northwesterly winds and seas across the coastal waters through
early next week. Winds will strengthen by midweek as high pressure
builds over the eastern pacific.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...None.
$$
PUBLIC FORECAST: Bell
AVIATION: CW
MARINE: CW
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook and twitter at:
www.Facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
[top]
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
208 PM PDT SUN MAY 22 2016
.SYNOPSIS...
Cooler than normal temperatures will continue over the central
California interior for much of this week as an upper level trough
resides along the west coast. Showers and thunderstorms are possible
Monday through Thursday over the southern Sierra Nevada.
&&
.DISCUSSION...The combination of an onshore flow and an upper
level trough along the West coast is keeping temperatures below
normal across the CWA again this afternoon, despite a good deal of
sunshine in most areas. The air is cold enough aloft to generate
some cumulus clouds over the higher terrain this afternoon but
stability indices are strong enough to cap any deep convection.
The atmosphere will become increasingly unstable over the central
Calfornia interior during the next couple of days, however, as an
upper level disturbance rotates through the base of this trough.
By Monday afternoon and evening...isolated showers and tstorms are
possible over the foothills and higher elevations of the Sierra.
Tuesday will likely become more active as the upper level
disturbance hovers near the central California coast. With the
exception of the Kern County desert, thunderstorms could pop up
just about anywhere over the CWA Tuesday and linger until just
after sunset. This even includes the San Joaquin Valley. However,
showers and thunderstorms will probably be more numerous over the
mountains Tuesday afternoon and evening. A recurrence of showers
and thunderstorms is likely over the mountains Wednesday afternoon
as the upper level disturbance drifts into southern California.
A slightly drier and more stable air mass will settle into the
CWA later this week as this feature moves into the Four Corners
region and finally exits into the southern Plains states Friday.
By then, only the highest elevations of the Sierra face a risk of
isolated afternoon thunderstorms.
The models forecast another upper level trough to develop along
the West Coast next weekend. We are not very confident that there
will be enough moisture and instability associated with this
trough to generate any more than cumulus buildups over the Sierra
by next Sunday. The GFS deepens this trough more significantly
than the ECM, so if this solution ends up being right, we will
probably not get through the entire Memorial Day weekend without
at least a slight chance of thunderstorms over the Sierra. This
is something hikers and back packers will need to keep on the
back of their minds if their destination includes the high Sierra
during the holiday weekend.
The good news is that temperatures will average cooler than normal
during the next week or so. Of the next 7 days, Friday looks to
be the warmest day. Even then, high temps will still fall at least
a few degrees shy of climatological normals.
&&
.AVIATION...
Areas of MVFR ceilings can be expected along the north facing slopes
of the Tehachapi mountains and the west facing slopes of the Sierra
between 09z and 18z Monday. Isolated thunderstorms will develop over
the Sierra Monday afternoon with local MVFR ceilings. VFR conditions
can be expected elsewhere across the central California interior
during the next 24 hours.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
NONE.
&&
$$
public...Durfee
avn/fw...Durfee
synopsis...DS
weather.gov/hanford
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1052 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 10:52 AM PDT Sunday...Low clouds prevail across
the area as a result of a very moist boundary layer. MVFR cigs
expected across area terminals this morning with clearing
anticipated after noon today. 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...MVFR cigs will prevail til 19Z-20Z 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 conditions will prevail through this
evening. Generally light onshore winds through forecast period.
&&
.MARINE...as of 10:44 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: RC/CW
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook and twitter at:
www.Facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
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
[top]
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
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
[top]
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
1139 PM CDT SUN MAY 22 2016
.UPDATE...
Issued at 1139 PM CDT Sun May 22 2016
We just made another quick update to remove one more row of
counties from the severe thunderstorm watch...including Burleigh
County. Thus, Bismarck is no longer in the watch.
UPDATE Issued at 1040 PM CDT Sun May 22 2016
Quick update to cancel the western parts of severe thunderstorm
watch 192. The effective cold front, which has been partly re-
inforced by storm outflow, has moved east of a Minot to Fort
Yates line as of 0330 UTC. The severe threat has ended west of
the front. We are maintaining the watch east of there for now
given modest instability and moderate to strong deep-layer shear,
but radar trends suggest the severe threat is marginal.
UPDATE Issued at 859 PM CDT Sun May 22 2016
MODERATE INSTABILITY REMAINS OVER CENTRAL INTO EASTERN NORTH
DAKOTA ALONG WITH SUFFICIENT DEEP LAYER SHEAR TO RESULT IN A
CONTINUED SEVERE THREAT AHEAD OF A COLD FRONT DROPPING THROUGH
CENTRAL NORTH DAKOTA. STORMS HAVE HAD TROUBLE BECOMING VERY
STRONG...THOUGH HAVE HAD REPORTS OF PROLIFIC SMALLER HAIL
PRODUCING STORMS ALONG WITH HEAVIER RAIN PRODUCERS OVER THE JAMES
RIVER VALLEY REGION WHERE HIGHEST PRECIPITABLE WATER VALUES WERE
NOTED. SOME POST FRONTAL STORMS ALSO CONTINUE TO DEVELOP WHICH MAY
BE SPAWNED BY AN UPPER LEVEL JET STREAK LIFTING THROUGH THE
REGION. WILL KEEP CURRENT SEVERE WATCH IN TACT.
UPDATE Issued at 605 PM CDT Sun May 22 2016
Thunderstorms are starting to develop over western into south
central North Dakota. Stage is still set with increased
instability and sufficient deep layer shear to support severe
storms with large hail and damaging wind gusts as the main
threats. Plenty of moisture continues to surge in ahead of
gradually progressing cold front (dewpoints in the lower 60s) to
bring the risk of heavy rainfall from some storms. The area with
the greatest risk for this continues to be over south central
North Dakota into the James River Valley.
&&
.SHORT TERM...(This evening through Monday)
Issued at 206 PM CDT Sun May 22 2016
Severe thunderstorms highlight the short term period
The latest water vapor imagery shows a closed low circulating
over Alberta with a 100kt jet streak stretched out from northeast
Montana into central Wyoming. This jet streak nudges east into
western North Dakota this evening. This will provide large scale
ascent along a cold frontal boundary, now located from Portal to
Stanley, and south into Hettinger. Dewpoints in the west are in
the lower 40s while in central North Dakota moisture is higher
with dewpoints near 60F. The cold front will slowly move east
tonight, exiting the James River Valley between 09z-12z Monday.
Visible imagery showing stratus eroding which will initiate and
increase low level buoyancy and instability. The HRRR and NAM look
to have a good trend with convection initiation. The most intense
cells begin near Lemmon SD and develop within a corridor between
Dickinson and Bismarck, and narrowing but continuously developing
towards Minot from 4pm-7pm cdt. This consolidates into a line of
thunderstorms that slides into the James River Valley this
evening. Another area of severe and/or heavy rain develops in
south central ND between 7pm and midnight. This is forecast to
move northeast and expand into the James River Valley with heavy
rainfall late evening into the overnight period. Large hail,
damaging winds, and heavy rainfall continue as the main threats
late this afternoon through tonight. Flash flooding possible in
the southern James River Valley late this evening into the
overnight period. More stable air shifts from west to east tonight
ending the precipitation after midnight.
.LONG TERM...(Monday night through Sunday)
Issued at 206 PM CDT Sun May 22 2016
Broad trough over the western CONUS gradually works eastward towards
the plains through the middle and end of the upcoming week. This
will bring active cyclonic flow to the area, though models are
having quite a bit of trouble with timing out individual short waves
within the system. With that said, will keep chances for
precipitation going given the active pattern. Near to slightly above
average temperatures expected.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 1040 PM CDT Sun May 22 2016
Thunderstorms will gradually end from west to east tonight, but
are forecast to linger longest over the James River Valley. Local
IFR ceilings and visibilities with heavy rain and gusty winds are
expected with some storms. VFR conditions are expected on Monday
behind the cold front crossing the area tonight.
&&
.BIS Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...JJS
AVIATION...JJS/CJS
AREA FORECAST DISCUSSION
NWS Tulsa OK
1144 PM CDT SUN MAY 22 2016
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Convection across western OK will make a run at eastern OK and
have introduced VCTS for the OK TAF sites around 10z...with
VCSH for the AR sites toward 15z. While brief MVFR conditions
can`t be ruled out...expect mainly VFR through the period.
&&
.PREV DISCUSSION... /ISSUED 853 PM CDT SUN MAY 22 2016/
..UPDATE...
DISCUSSION...
Ongoing thunderstorms in the eastern panhandles making slow
eastward progress. The expectation continues that much of this
will diminish before reaching eastern Oklahoma, with perhaps only
areas along and west of Highway 75 seeing any remnants. Of this
area, it appears that parts of southeast Oklahoma would be the
most favored at this point, given recent data from the HRRR and
current location of the most developed area of convection. Have
made a few minor tweaks to the POPs after 06Z to account for this
thinking, as well as minor changes to the Sky grids to spread
cloud cover into northwest Arkansas faster. Updated forecast
products coming soon.
PREV DISCUSSION... /ISSUED 623 PM CDT SUN MAY 22 2016/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR conditions expected through the period. Scattered showers
and thunderstorms possible for eastern OK TAF sites late tonight
and into Monday morning.
PREV DISCUSSION... /ISSUED 359 PM CDT SUN MAY 22 2016/
DISCUSSION...
The upper ridge is shifting off to the east and we will be under
the influence of the western U.S. trough for at least the next
week or so. The dryline will remain well to our west for most of
the week, but we will be at risk of seeing at least the remnants
of any storms that develop well to our west making it far enough
east to affect us. Weak impulses moving out of the western trough
may also trigger scattered showers and storms within our forecast
area just about any day this week. Instability will be sufficient
for severe storms, especially from Tuesday on.
The main upper system will finally lift northeast into the central
Plains by Friday, perhaps 12 hours or so sooner than it appeared
at this time yesterday. Thus Friday will likely see the greatest
precipitation coverage, and greatest severe weather risk, of the
week.
Even after this system lifts out, another trough develops near the
West Coast, and the dryline gets left behind to our west, so storm
chances will continue through next weekend, as will the warm and
humid conditions.
Stayed close to guidance temperatures the next couple days.
TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
$$
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 66 83 69 85 / 10 40 30 30
FSM 62 86 67 84 / 10 30 20 30
MLC 67 83 70 82 / 20 30 30 30
BVO 64 82 67 84 / 10 40 30 30
FYV 58 82 64 80 / 0 20 20 30
BYV 58 82 64 80 / 0 20 20 30
MKO 63 83 68 83 / 10 30 30 30
MIO 63 83 67 82 / 10 30 30 30
F10 66 82 69 83 / 20 40 30 30
HHW 65 85 69 84 / 30 30 30 30
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...18
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
345 AM PDT MON MAY 23 2016
.SYNOPSIS...
A trough of low pressure over the western states
will strengthen a little through Wednesday...then weaken again for
next weekend. High temperatures will remain below average for
inland areas through much of the week...then warm towards the end
of the week into next weekend. A deep marine layer will bring
areas of night and morning low clouds and patchy fog for coastal
areas inland to the coastal mountain slopes. There are small
chances for light precipitation along and west of the mountains
for late tonight into Tuesday morning and again late Tuesday night
into Wednesday morning with a slight chance of thunderstorms near
the mountains Wednesday afternoon. There will continue to be
periods of gusty west winds in the mountains and deserts...stronger
during the late afternoon and evening each day.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Today through Wednesday)...
Broad low pressure extends across the western states. Within that
broader low pressure...a shortwave off the California coast will
move inland through Southern California tonight and Tuesday. This
will bring deepening of the marine layer with a slight chance of
light showers along and west of the coastal slopes of the
mountains for late tonight into Tuesday morning. A second
shortwave moving southward just off the West Coast will move
inland through Southern California Tuesday night and Wednesday as
a closed low pressure system. This will bring a slight chance of
light showers along and west of the coastal slopes of the
mountains late Tuesday night into Wednesday morning. With the
coldest mid level air moving across Southern California
Wednesday...there is a slight chance of thunderstorms Wednesday
afternoon...mainly near the mountains and inland valleys. Inland
high temperatures will cool slightly through Wednesday with gusty
west winds in the mountains and deserts...strongest during the
late afternoon and evening each day.
&&
.LONG TERM (Thursday through Sunday)...
The trough of low pressure will weaken for Thursday and Friday. A
low pressure system moving into the Pacific Northwest on Saturday
will maintain the low pressure trough into Southern California
through the Memorial Day weekend. Areas of night and morning
coastal low clouds and patchy fog will continue with slow warming
of inland high temperatures.
&&
.AVIATION... 230900Z...Coast/Valleys...Mostly scattered, but
occasionally broken low clouds will continue through 18z. Cigs would
be around 2500 feet msl with tops to 3200 feet. After 02z scattered
clouds will become more broken overnight with bases around 2500 feet
msl.
Mountains/Deserts...West winds with local gusts of 30-40 mph will
produce weak to moderate up/down drafts over and east of the
mountains through tonight. Otherwise, mostly clear.
&&
.MARINE...
200 AM...Wind gusts near 20 knots at times this evening over the
outer waters. Otherwise, no hazardous marine weather is expected
through Friday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...None.
PZ...None.
&&
$$
PUBLIC...17
AVIATION/MARINE...MM
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
330 AM PDT MON MAY 23 2016
.SYNOPSIS
An upper level disturbance will continue to bring unsettled weather
and cool conditions across NorCal this week.
&&
.SHORT TERM
Clear to partly cloudy skies across interior NorCal early this
morning. Temperatures are pretty similar to readings from 24 hours
ago and generally range from the 30s and 40s in the mountains to
the upper 40s and 50s elsewhere.
Long-wave trough will remain in place over the West through the
period maintaining cool and unsettled weather for the region. Weak
circulation evident on satellite imagery to the west of the Bay
Area (37N/129W) is forecast to move toward central California
today and may provide the trigger for another upswing in shower
and thunderstorm activity by this afternoon. Most of the action is
expected over the foothills and mountains, but the HRRR is
indicating that some showers may develop in the Sacramento region
(NE quad of the approaching low) around the afternoon commute
time.
Tuesday is expected to be quite similar to today as the weak low
continues to hang out over central California. With cloud cover
and a rather cool airmass remaining across the region,
temperatures will remain below average.
Less coverage of showers and thunderstorms are expected across
NorCal on Wednesday and Thursday as the low shifts south and east
of the area. Temperatures will gradually warm each day as the
airmass modifies and most areas see more sunshine.
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
The long term forecast period should begin dry for interior
northern California as a shortwave ridge of high pressure begins
to break down. High temperatures are looking to return to near
normal into the lower to mid 80s the valley and the 50s and 60s
for the higher elevations. Another upper level system is depicted
in model forecasts to slide across the Pacific NW Friday night
into Saturday, and a portion of the jet stream could clip
northern California. As a result, there will be the possibility of
some showers and isolated thunderstorms for northern portions of
the Sierra and southern Cascades for next weekend. Any snow
accumulations should remain confined to the upper elevations,
which should not affect mountain pass travel.
Model forecasts are in decent agreement as to the amplitude and
general timing pattern of the upper level low for next weekend,
however the progression differs slightly as to when the system will
clear northern California. Although there are slight differences in
the forecast scenarios, the beginning of next week should dry out as
a ridge builds back into the west from the eastern Pacific.
&&
.AVIATION
VFR conditions are expected for the terminals for the next 24
hours with light wind shifts. An upper level trough continues to
linger over northern California, which will result in BKN to OVC
ceilings for most flight times during the forecast period for the
TAF sites.
Showers and thunderstorms today should stay confined
to higher elevations, although portions of the northern valley
near KRDD and KRBL could also see some shower or thunderstorm activity.
Confidence is low as to showers developing within the vicinity of
the terminals, so left mention out of the TAF for now.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
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
[top]
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
NWS Tulsa OK
928 AM CDT MON MAY 23 2016
.DISCUSSION...
The Overnight MCS across southern OKlahoma and northern Texas
has left an MCV over northeast Oklahoma this morning. This feature
will continue to have convection associated with it for the next
several hours as it moves off to the northeast with adequate elevated
instability in place. The convection may become a little more concentrated
around the MCV with the activity further south diminishing. Have made
some adjustment to the pops for Today to take this into account.
&&
.PREV DISCUSSION... /ISSUED 549 AM CDT MON MAY 23 2016/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Ongoing convection now entering eastern OK will continue to spread
eastward through the morning. The most likely aviation impact will
be across SE OK nearer the stronger storms. Thinking is that once
this convection dissipates then any redevelopment will be most
likely west of the area with storms possibly spreading into the
area early Tuesday morning.
PREV DISCUSSION... /ISSUED 435 AM CDT MON MAY 23 2016/
DISCUSSION...
The synoptic features from yesterday remain largely in play and
nearly in the same locations early this morning. The one
exception is that the ridge of high pressure has shifted east
southeast some...becoming more positively tilted as the longwave
trof settled over the Desert Southwest United States. Also this
morning...the dryline off the surface low over Eastern Colorado
continued to extend southward into far Eastern New Mexico.
Scattered convection that had developed yesterday along the
dryline had formed into a MCS across Southern Oklahoma...
approaching Southeast Oklahoma over the next couple of hours.
Across the rest of Eastern Oklahoma and Northwest Arkansas...
cloudy conditions with east to southeasterly winds were common.
The MCS will continue to push eastward into/across Southeast
Oklahoma this morning and potentially spreading into Northeast
Oklahoma and Northwest Arkansas this afternoon. An instability
axis remained just west of the CWA this morning...which could help
to weaken the overall intensity of the MCS...however gusty to
locally damaging winds could be possible with this activity.
Also...additional showers and thunderstorms will be possible
across the CWA through this evening as any leftover outflow
boundaries from the morning activity remain over the region.
Breezy southerly winds transporting moisture back into the region
combined with near seasonal average temperatures underneath a
destabilizing atmosphere could allow for any thunderstorm activity
through this evening to become strong to severe with large hail
and locally damaging winds being the main threats. The greater
severe potential though should remain west of the CWA...closer to
the dryline.
Also this afternoon...additional convection is expected to fire
along/near the dryline again...which will have the potential to
cluster together into another MCS and move into the CWA overnight
tonight. The instability axis overnight tonight looks to be a
little more eastward than where it is this morning. This will aid
in a continued severe potential overnight tonight over the
CWA...with locally damaging winds being possible.
Tuesday through Thursday...the longwave trof is forecast to stall
over the Southwest United States with west to southwesterly upper
level flow over the Plains. Weak impulses within this flow moving
across the Plains along with the dryline remaining over Western
Kansas and the Oklahoma/Texas Panhandles will give a "rinse-wash-
repeat" for thunderstorm chances each day over the CWA. Any
convection along the dryline could form into an MCS at night and
approach/move into the region...with additional daytime
thunderstorm chances as the weak impulses interact with any
leftover outflow boundaries. These conditions along with a
continued unstable atmosphere will allow at least limited severe
potentials through Thursday over Eastern Oklahoma and Northwest
Arkansas.
Latest model solutions continue to show the wave over the
Southwest United States finally lifting into the Plains
Friday...thus increasing thunderstorm chances again for the CWA.
Indications are that the wave could possibly move into the region
during the morning hours which could help to limit severe
potential...though with this several days away...will continue to
monitor latest data as this set up could likely change back-and-
forth several times. For the upcoming weekend...thunderstorm
chances will continue to be possible as another wave looks to
quickly develop and lift out of the Southwest United States into
the Plains.
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...10
[top]
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
928 AM CDT MON MAY 23 2016
.UPDATE...
Quick morning update to thunderstorm chances through this
evening.
&&
.DISCUSSION...
Jumping on the forecast early this morning given the chance for
severe storms developing on/just east of the Caprock and moving
into far western north Texas and southwestern Oklahoma late this
Afternoon and evening. Guidance, both traditional and mesoscale,
are in decent agreement with the redevelopment of the dryline on
the Llano Estacado and its mixing eastward through the mid
afternoon across the Texas and Oklahoma Panhandles. Dew points
across the Panhandles to central Oklahoma continue to reside in
the low to mid 60s, with sites farther south in western north
Texas already reaching the upper 60s to near 70s. the MCS that
moved across southern Oklahoma and northern Texas overnight has
had some impact, but recovery is already well underway farther
west. The fly in the ointment at the moment is the broken to
overcast stratus spread across the area. In western Oklahoma,
breaks have been farily evident, and temperatures are already in
the upper 60s and lower 70s. Agree with the night shift and with
latest SPC outlook, some form of a triple point will develop
south/southeast of the Red River, east of the Caprock this
afternoon. Solutions from the HRRRx and TTU WRF continue to pick
this as the primary initiation point. The operational HRRR and
traditional guidance continue to fire convection along a surging
point in the dryline early this afternoon in northwestern
Oklahoma/southwestern Kansas. This is likely overdone given the
current conditions, overcast skies, limiting heating this morning.
However, isolated thunderstorms may develop in the region, but
probably not as widespread as some of the solutions attempt.
Therefore, increased precip chances to likelys across southern
Oklahoma and western north Texas from late this afternoon through
the evening and into the overnight hours. Confidence is high for
storm development and and increase from chance PoPs was necessary.
Not to rehash the previous discussion, but instability and shear
will be plenty enough for the development of large damaging hail,
damaging winds, and the possiblity of a few tornadoes.
Of greater concern for many will be the potential for flooding
overnight, espcecially across portions of southern Oklahoma and
northern Texas where excessive rainfall fell last night and this
morning. Once again, this afternoon`s storms are expected to merge
into a complex and propogate eastward overnight, slowly. A flood
watch is in effect for this region and may need to be extended, but
this will be addressed with the afternoon forecast.
Kurtz
&&
.PREV DISCUSSION... /issued 850 AM CDT MON MAY 23 2016/
UPDATE...
Updated pops and slowed diurnal warming trend this morning.
DISCUSSION...
Showers/storms continue to move east with a new area of storms
that developed just east of OKC/Norman. Have updated short-term
pops with the latest trends in radar and satellite. HRRR/RAP and
various hi-res models show redevelopment before 18z across
northwest and central Oklahoma so have adjusted late morning pops
to account for this possibility. And made significant changes to
the hourly temperatures and dewpoints given the cloud cover will
keep temperatures cooler this morning and the post-convective
worked over airmass keeping dewpoints lower. Still expect we will
see eventual recovery to forecast highs, but it will likely take
some time.
PREV DISCUSSION... /issued 659 AM CDT MON MAY 23 2016/
DISCUSSION...
Please see the 12Z aviation discussion below.
AVIATION...
A few thunderstorms remain near SPS and OKC/OUN early this
morning, and may continue for a couple more hours. Otherwise,
expect MVFR cigs to return late this morning for a few terminals
before becoming VFR by this afternoon. Showers and thunderstorms
are expected again tonight, mainly after 00Z. Confidence in timing
is not exceptional, however, so expect some amendments/changes to
future TAFS.
PREV DISCUSSION... /issued 405 AM CDT MON MAY 23 2016/
DISCUSSION...
An MCS continues its track across southern OK and north TX early
this morning. Very heavy rainfall and damaging winds accompanied
it earlier, and are still expected across southern OK through the
early morning hours. Most of this activity should move out of our
area near or before sunrise. Later this afternoon storms will
initiate along the dryline again from the southeastern TX
panhandle into western and northwestern OK, and move east during
the evening hours. Supercells will be likely, with ALL severe
weather threats possible. The highest rainfall totals are again
expected over western and southwestern OK, and western north TX.
These areas already received a significant amount of rainfall this
morning so we have decided to issue a Flood Watch thru early Wed
AM.
The overall forecast has changed very little for the work week.
The severe threat will continue to shift slowly east each day
with the dryline and approaching upper trough. The tornado threat
should also increase during the late afternoon and early evening
hours with the onset of the LLJ, especially across western and
southwestern OK by Tue. There may be a break in COVERAGE Wednesday with
surface convergence becoming a bit more diffuse along the
dryline. However, if any isolated supercells can manage to develop
they will again be capable of producing ALL severe weather
threats.
By Thursday, a southern stream mid to upper level shortwave trough
is expected to lift over northeast TX and into SE OK around mid
day. Heavy rainfall and embedded supercells will be possible with
this activity. Further west, the upper trough will begin to near
the southern plains with rapid height falls and increasing mid to
upper flow expected over the dryline across western OK.
Widespread severe weather continues to appear possible thru
Thursday night, including the threat of tornadoes. Finally, by
Friday, the upper trough will being to lift northeastward but will
not pass overhead until late Friday night. Additional severe
weather will remain possible from along/just west of I35 through
eastern OK.
Additional storm chances are expected through the weekend and into
early next week as another upper trough moves over the western
CONUS and WSW flow aloft ahead of it continues over the Southern
Plains.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 81 67 83 68 / 30 50 20 50
Hobart OK 83 68 87 69 / 40 60 50 40
Wichita Falls TX 84 69 87 71 / 20 70 30 30
Gage OK 89 67 91 64 / 30 40 20 30
Ponca City OK 81 68 83 69 / 40 40 30 50
Durant OK 83 70 83 70 / 80 50 30 40
&&
.OUN Watches/Warnings/Advisories...
OK...Flood Watch from 3 PM CDT this afternoon through Wednesday
morning for OKZ021>023-027-033>039-044-045.
TX...Flood Watch from 3 PM CDT this afternoon through Wednesday
morning for TXZ083>090.
&&
$$
09/04
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
936 AM PDT MON MAY 23 2016
.SYNOPSIS...
A low pressure trough will continue to deepen over the
west coast today. This feature will bring onshore flow, below normal
inland temperatures, and a deep marine layer responsible for the
night and morning low clouds. Light rain or drizzle is possible west
of the mountains tonight into Tuesday morning, then again Tuesday
night into Wednesday morning. On Wednesday, a weak low pressure
disturbance will bring a slight chance of showers and thunderstorms
to the inland valleys and mountains. A trough along the West coast
will remain stagnant over the region through this weekend,
maintaining the low clouds west of the mountains, onshore flow,
and below normal temperatures.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AT 8 AM PDT...Water vapor imagery showed broad troughing draped
along the west coast with the center of low pressure located over
northern California. The 12z KNKX sounding indicated the marine
temperature inversion at 2600 ft msl with dry air aloft. Onshore
surface pressure gradients have nearly doubled in strength as
compared to 24-hours ago with SAN-TPH now +5.7 mb and SAN-DAG +5.4
mb.
As the west coast trough deepens today, scattered low clouds will
persist west of the mountains and breezy westerly winds will develop
in the mountains and deserts. Temperatures along the coast are
forecast around 5 degrees below normal with inland temperatures 10
to 15 degrees below normal for this time of year. Tonight, the local
WRF model depicts the stratus marine layer deepening to around 4000
ft msl and generates patchy light rain or drizzle west of the
mountains. Synoptically little changes on Tuesday. Breezy westerly
winds will continue across the mountain tops and desert slopes with
inland temperatures on the cool side, 10 to 20 degrees below normal.
Tuesday night into Wednesday, both the 12Z GFS and 00Z ECMWF drop a
distinct vort max southward towards Southern California. This
feature will once again act to deepen the marine layer Tuesday night
and maintain gusty westerly winds in the mountains and deserts.
Patchy light rain or drizzle will again be a possibility west of the
mountains. As the center of the low moves overhead on Wednesday, 500
mb temps lower to near -20 C. This cold and marginally unstable air
aloft, combined with limited moisture, will generate a slight chance
of showers and thunderstorms in the mountains and inland valleys
through the afternoon. Temperatures on Wednesday will be well below
normal, especially inland and over the mountains with a handful of
mountain locations forecast 20-25 degrees below normal.
A rather stagnant weather pattern holds in place through the end of
the weekend and into early next as the west coast trough remains in
place. So Cal residents can expect more night and morning low clouds
west of the mountains, onshore flow, and below normal temperatures.
&&
.AVIATION...
231515Z...Coast/Valleys...Areas of bkn low clouds based
mainly 2000-3000 ft MSL with tops to near 3500 ft MSL.
After about 23/19Z becoming mostly scattered. Confidence in
conditions becoming scattered by afternoon today is high. After
about 24/02Z this evening scattered clouds will become more broken
into the night with bases mainly around 2000-3000 feet MSL and tops
around 3500 ft MSL. Risk of bkn low clouds with bases below 2000
feet MSL at times tonight is moderate-high at KSAN.
Mountains/Deserts...Lower coastal slopes below 3500 ft locally
obscured before 23/18Z otherwise mostly clear. West winds with local
gusts of 30-40 mph will produce weak to moderate up/down drafts over
and east of the mountains through tonight.
&&
.MARINE...
815 AM...Wind gusts near 20 knots at times through this evening
over the outer waters. Otherwise, no hazardous marine weather
is expected through Friday.
&&
.SKYWARN...
Skywarn activation will not be needed today.
&&
.SGX Watches/Warnings/Advisories...
CA...None.
PZ...None.
&&
$$
PUBLIC...JT
AVIATION/MARINE...Small
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
915 AM PDT MON MAY 23 2016
.SYNOPSIS...
An upper level disturbance will continue to bring unsettled weather
and cool conditions across NorCal this week.
&&
.Short Term Discussion...
Forecast largely on track this morning. Latest hi-res guidance
continues to indicate showers popping up over next several hours
with coverage expanding into the afternoon. Showers will generally
remain over higher elevations but cannot rule out a shower or two
in the Valley. Modest instability will be present as shortwave
moves across the area, so isolated thunderstorms are possible as
well. Accumulations will generally be light although locally
heavier amounts possible in any thunderstorm. Afternoon
temperatures will top out in the low to mid 70s in the Valley with
40s-60s across higher elevations. CEO
.Previous Discussion...
Clear to partly cloudy skies across interior NorCal early this
morning. Temperatures are pretty similar to readings from 24 hours
ago and generally range from the 30s and 40s in the mountains to
the upper 40s and 50s elsewhere.
Long-wave trough will remain in place over the West through the
period maintaining cool and unsettled weather for the region. Weak
circulation evident on satellite imagery to the west of the Bay
Area (37N/129W) is forecast to move toward central California
today and may provide the trigger for another upswing in shower
and thunderstorm activity by this afternoon. Most of the action is
expected over the foothills and mountains, but the HRRR is
indicating that some showers may develop in the Sacramento region
(NE quad of the approaching low) around the afternoon commute
time.
Tuesday is expected to be quite similar to today as the weak low
continues to hang out over central California. With cloud cover
and a rather cool airmass remaining across the region,
temperatures will remain below average.
Less coverage of showers and thunderstorms are expected across
NorCal on Wednesday and Thursday as the low shifts south and east
of the area. Temperatures will gradually warm each day as the
airmass modifies and most areas see more sunshine.
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
The long term forecast period should begin dry for interior
northern California as a shortwave ridge of high pressure begins
to break down. High temperatures are looking to return to near
normal into the lower to mid 80s the valley and the 50s and 60s
for the higher elevations. Another upper level system is depicted
in model forecasts to slide across the Pacific NW Friday night
into Saturday, and a portion of the jet stream could clip northern
California. As a result, there will be the possibility of some
showers and isolated thunderstorms for northern portions of the
Sierra and southern Cascades for next weekend. Any snow
accumulations should remain confined to the upper elevations,
which should not affect mountain pass travel.
Model forecasts are in decent agreement as to the amplitude and
general timing pattern of the upper level low for next weekend,
however the progression differs slightly as to when the system will
clear northern California. Although there are slight differences in
the forecast scenarios, the beginning of next week should dry out as
a ridge builds back into the west from the eastern Pacific.
&&
.AVIATION...
VFR conditions are expected for the terminals for the next 24
hours with light wind shifts. An upper level trough continues to
linger over northern California, which will result in BKN to OVC
ceilings for most flight times during the forecast period for the
TAF sites.
Showers and thunderstorms today should stay confined
to higher elevations, although portions of the northern valley
near KRDD and KRBL could also see some shower or thunderstorm activity.
Confidence is low as to showers developing within the vicinity of
the terminals, so left mention out of the TAF for now.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
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
[top]
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
NWS Tulsa OK
1247 PM CDT MON MAY 23 2016
.DISCUSSION...
Showers and thunderstorms continue to persist across Osage County
this afternoon as a 35kt low level jet continues to funnel into
that area. The MCV continue across northeast Oklahoma with the
majority of the convection associated with this feature fading.
Have adjusted the pops and temperatures for this afternoon with
the cloud cover expected to keep temperatures a few degree lower.
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...10
[top]
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
1205 PM CDT MON MAY 23 2016
.AVIATION...23/18Z TAF ISSUANCE...
Tricky aviation forecast over the next several hours. Broken to
overcast MVFR ceilings will continue to impact airfields and TAF
sites across portions of central and southern Oklahoma through the
mid to late afternoon. Across western Oklahoma and western north
Texas, scattered to broken MVFR ceilings will continue to improve
to VFR through the afternoon. The biggest concern for aviation
will be thunderstorm development late this afternoon and evening
across portions of western Oklahoma and western north Texas.
Confidence in timing and coverage has increased for TAF sites
across the southwest, including KCSM/KHBR/KLAW/KSPS. Therefore,
utilized TEMPO groups, after 00Z for most. Expect a complex of
storms to develop similar to last night, primarily impacting
southern Oklahoma and northern Texas overnight.
Kurtz
&&
.PREV DISCUSSION... /issued 928 AM CDT MON MAY 23 2016/
UPDATE...
Quick morning update to thunderstorm chances through this
evening.
DISCUSSION...
Jumping on the forecast early this morning given the chance for
severe storms developing on/just east of the Caprock and moving
into far western north Texas and southwestern Oklahoma late this
Afternoon and evening. Guidance, both traditional and mesoscale,
are in decent agreement with the redevelopment of the dryline on
the Llano Estacado and its mixing eastward through the mid
afternoon across the Texas and Oklahoma Panhandles. Dew points
across the Panhandles to central Oklahoma continue to reside in
the low to mid 60s, with sites farther south in western north
Texas already reaching the upper 60s to near 70s. the MCS that
moved across southern Oklahoma and northern Texas overnight has
had some impact, but recovery is already well underway farther
west. The fly in the ointment at the moment is the broken to
overcast stratus spread across the area. In western Oklahoma,
breaks have been fairly evident, and temperatures are already in
the upper 60s and lower 70s. Agree with the night shift and with
latest SPC outlook, some form of a triple point will develop
south/southwest of the Red River, east of the Caprock this
afternoon. Solutions from the HRRRx and TTU WRF continue to pick
this as the primary initiation point. The operational HRRR and
traditional guidance continue to fire convection along a surging
point in the dryline early this afternoon in northwestern
Oklahoma/southwestern Kansas. This is likely overdone given the
current conditions, overcast skies, limiting heating this morning.
However, isolated thunderstorms may develop in the region, but
probably not as widespread as some of the solutions attempt.
Therefore, increased precip chances to likelys across southern
Oklahoma and western north Texas from late this afternoon through
the evening and into the overnight hours. Confidence is high for
storm development and and increase from chance PoPs was necessary.
Not to rehash the previous discussion, but instability and shear
will be plenty enough for the development of large damaging hail,
damaging winds, and the possibility of a few tornadoes.
Of greater concern for many will be the potential for flooding
overnight, especially across portions of southern Oklahoma and
northern Texas where excessive rainfall fell last night and this
morning. Once again, this afternoon`s storms are expected to merge
into a complex and propagate eastward overnight, slowly. A flood
watch is in effect for this region and may need to be extended,
but this will be addressed with the afternoon forecast.
Kurtz
PREV DISCUSSION... /issued 850 AM CDT MON MAY 23 2016/
UPDATE...
Updated pops and slowed diurnal warming trend this morning.
DISCUSSION...
Showers/storms continue to move east with a new area of storms
that developed just east of OKC/Norman. Have updated short-term
pops with the latest trends in radar and satellite. HRRR/RAP and
various hi-res models show redevelopment before 18z across
northwest and central Oklahoma so have adjusted late morning pops
to account for this possibility. And made significant changes to
the hourly temperatures and dewpoints given the cloud cover will
keep temperatures cooler this morning and the post-convective
worked over airmass keeping dewpoints lower. Still expect we will
see eventual recovery to forecast highs, but it will likely take
some time.
PREV DISCUSSION... /issued 659 AM CDT MON MAY 23 2016/
DISCUSSION...
Please see the 12Z aviation discussion below.
AVIATION...
A few thunderstorms remain near SPS and OKC/OUN early this
morning, and may continue for a couple more hours. Otherwise,
expect MVFR cigs to return late this morning for a few terminals
before becoming VFR by this afternoon. Showers and thunderstorms
are expected again tonight, mainly after 00Z. Confidence in timing
is not exceptional, however, so expect some amendments/changes to
future TAFS.
PREV DISCUSSION... /issued 405 AM CDT MON MAY 23 2016/
DISCUSSION...
An MCS continues its track across southern OK and north TX early
this morning. Very heavy rainfall and damaging winds accompanied
it earlier, and are still expected across southern OK through the
early morning hours. Most of this activity should move out of our
area near or before sunrise. Later this afternoon storms will
initiate along the dryline again from the southeastern TX
panhandle into western and northwestern OK, and move east during
the evening hours. Supercells will be likely, with ALL severe
weather threats possible. The highest rainfall totals are again
expected over western and southwestern OK, and western north TX.
These areas already received a significant amount of rainfall this
morning so we have decided to issue a Flood Watch thru early Wed
AM.
The overall forecast has changed very little for the work week.
The severe threat will continue to shift slowly east each day
with the dryline and approaching upper trough. The tornado threat
should also increase during the late afternoon and early evening
hours with the onset of the LLJ, especially across western and
southwestern OK by Tue. There may be a break in COVERAGE Wednesday with
surface convergence becoming a bit more diffuse along the
dryline. However, if any isolated supercells can manage to develop
they will again be capable of producing ALL severe weather
threats.
By Thursday, a southern stream mid to upper level shortwave trough
is expected to lift over northeast TX and into SE OK around mid
day. Heavy rainfall and embedded supercells will be possible with
this activity. Further west, the upper trough will begin to near
the southern plains with rapid height falls and increasing mid to
upper flow expected over the dryline across western OK.
Widespread severe weather continues to appear possible thru
Thursday night, including the threat of tornadoes. Finally, by
Friday, the upper trough will being to lift northeastward but will
not pass overhead until late Friday night. Additional severe
weather will remain possible from along/just west of I35 through
eastern OK.
Additional storm chances are expected through the weekend and into
early next week as another upper trough moves over the western
CONUS and WSW flow aloft ahead of it continues over the Southern
Plains.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 67 83 68 86 / 50 20 50 20
Hobart OK 68 87 69 90 / 60 50 40 20
Wichita Falls TX 69 87 71 90 / 70 30 30 20
Gage OK 67 91 64 93 / 40 20 30 10
Ponca City OK 68 83 69 88 / 40 30 50 20
Durant OK 70 83 70 84 / 50 30 40 20
&&
.OUN Watches/Warnings/Advisories...
OK...Flood Watch from 3 PM CDT this afternoon through Wednesday
morning for OKZ021>023-027-033>039-044-045.
TX...Flood Watch from 3 PM CDT this afternoon through Wednesday
morning for TXZ083>090.
&&
$$
09/04/04