Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/13/16
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1117 PM PDT SUN JUL 10 2016
...Aviation discussion updated...
.SYNOPSIS...
Upper-level low pressure over the Pacific Northwest will support
continued gusty northwest to north winds focused across the
mountains and interior valleys tonight. A warming trend will
occur through much of the workweek as high pressure aloft over the
Desert Southwest builds in. A low pressure system may build back
into the West Coast for next weekend and bring cooler conditions.
&&
.UPDATE...
The latest satellite imagery indicates a trough of low pressure
moving into the Northern Rockies this evening from the Pacific
Northwest, while a ridge of high pressure remains anchored over
the Desert Southwest. A northerly surface gradient continues to
create gusty winds across the Central Coast, Transverse Mountain
Ranges and the Antelope Valley and Santa Barbara South Coast.
Wind advisories for the Central Coast and the Antelope Valley will
likely be allowed to expire this evening, while remaining in
effect for the Los Angeles and Ventura County Mountains and
Southern Santa Barbara County through late tonight.
Fog product imagery indicates little, if any marine layer stratus
coverage this evening across Southwest California. A patch of
stratus is apparent off the Orange and San Diego County coastlines
this evening. An eddy circulation should develop tonight in the
low- level northwest flow parallel to the Southern California
coastline. Stratus coverage should spread back north into the area
after midnight and into Monday morning. Current stratus coverage
looks agreeable at this time and no changes are planned.
After a cool day on Monday, high pressure aloft over the Desert
Southwest will build and expand westward into the region through
much of the workweek. A warming trend will develop on Tuesday and
continue into late week.
&&
.SHORT TERM...(TDY-TUE)
Gale force NW winds across the outer waters will help to spin up
an eddy circulation across the SoCal bight tonight. Low clouds are
expected to deepen across L.A. and most of Ventura county coast
and valleys overnight into Monday. Confidence is good that low
clouds should reach the foothills of the San Gabriel Valley.
However with a sharp northerly wind gradient, the San Fernando
valley might not see widespread low clouds...especially across the
northern and western portions. Also the Ventura County interior
valleys could remain clear overnight. That being said, will not
not be surprised if all of LA,VTU county valleys see widespread
stratus. Have left low clouds out of the Santa Barbara South Coast
for early Monday morning as northerly winds should hold off any
stratus to develop. Yet off the coast the eddy could bring some
stratus just off the SBA coast by sunrise Monday.
As far as temps...inland areas will see a modest cooling trend
today and Monday...while coastal areas will continue to be within
a degree or two of the previous days. The one exception will be
the Santa Barbara South Coast due to the strong Sundowner wind
event expected late this afternoon. Highs should reach the mid to
upper 80s...with a few degrees of cooling on Monday as NW winds
will not be as strong across the SBA south coast.
By Tuesday, the upper trough will be well east of the area and the
upper ridge in nrn Mexico will expand back into Southern
California helping to warm inland temps once again. The marine
layer will stay in tact but some subsidence will cause the
inversion to strengthen and become more shallow. The Antelope
Valley and interior valleys will reach the mid 90s while coastal
valleys will be in the mid 80s to a few spots reaching the lower
90s. Still quite seasonable across coastal areas.
.LONG TERM...(WED-SAT)
Both the GFS and EC continue to agree that a 594 DM upper ridge
will expand back over the region from nrn Mexico on Wed and Thu.
This will cause the marine layer to become more shallow (between
800-1400 ft) still bringing areas of low clouds into the coastal
valleys each night through morning hours. Onshore flow will be a
tad weaker so inland areas should warm up into the 90s...while the
Antelope Valley reaches triple digit temps. The warmest day of the
week should be Thursday, with high temps away from the coast about
3-6 degrees above normal on Thursday.
By Friday...both the GFS and EC models continue to be in good
agreement indicating another upper level trough...(not as deep as
the one today) to move in over the region. This will cause high
temps to cool a few degrees across inland areas yet remaining
above average for this time of year. The marine layer will deepen
with a stronger onshore flow expected. Greater cooling expected
for next weekend.
&&
.AVIATION...10/06Z...
At 05Z at KLAX... the inversion was about 2950 feet deep. The top
of the inversion was around 3750 feet with a temperature near
21 degrees Celsius.
Overall... Moderate confidence in the 06z TAFs. The reduced
confidence is due to the uncertainty in the timing and intensity
of the marine incursion. IFR/MVFR conditions will move into KLAX
and KLGB by 10z and into KBUR, KVNY, and KOXR by 13z. The
conditions will dissipate in the valley by 17z and may linger
along the coast through 19z. Otherwise and elsewhere VFR
conditions will prevail.
KLAX... Moderate confidence in the 06z TAF. The reduced
confidence is due to the uncertainty in the timing and intensity
of the marine incursion. IFR/MVFR conditions will move in by 10z
and may linger through 19z. Otherwise VFR conditions will
prevail.
KBUR... Moderate confidence in the 06z TAF. The reduced
confidence is due to the uncertainty in the timing and intensity
of the marine incursion. There is a sixty percent chance of
IFR/MVFR conditions 13z-16z. Otherwise VFR conditions will
prevail.
&&
.MARINE...10/800 PM.
High confidence in northwest gales over the outer waters from
Piedras Blancas to San Nicolas Island through late tonight. Lower
confidence in Gales over the nearshore waters north of Point Sal,
and will lower to SCA after 8 PM this evening. Short period seas
around 10 feet at 7 seconds over the outer waters will pose
significant hazard to Small Craft. SCA conditions for the Santa
Barbara Channel will include gusty winds and hazardous seas 5 to
7 feet at 6 seconds.
Winds will diminish some by early Monday morning, but will remain
at SCA levels from the northwest with gusts to 30 knots through
Thursday. Seas will remain around 8 to 11 feet at 8 seconds
through Tuesday and then slowly diminish through Thursday.
Hazardous short period seas will affect portions of the inner
waters...including those north of Point Sal, the Santa Barbara
Channel, and outer portions of the waters west of L.A. County.
Moderate period south swells generated by Celia are expected to
begin to arrive Tuesday night.
&&
.FIRE WEATHER...10/300 PM
An upper level trough passing through California today will
continue to bring GUSTY northwest to north winds across the
region through tonight. The strongest winds will be focused across
the mountains...Antelope Valley, and Santa Barbara south coast
where gusts between 40 and 50 mph can be expected. Drier air will
continue to filter into the mountains and Antelope Valley this
afternoon and evening, with widespread humidities in the teens and
localized single digit readings across the higher peaks. The
combination of gusty winds and low humidities with very dry fuels
will bring critical red flag conditions to the mountains and
Antelope Valley through tonight.
The sundowner wind event is expected to be stronger and more
widespread than last night across the Santa Ynez mountains and
SBA south coast. Initially, the gusty sundowner winds will be
focused across western portions of the south coast and adjacent
foothills this afternoon, then winds will spread eastward across
the foothills this evening. The strongest winds in the foothills
above Santa Barbara and Montecito are expected to occur between 8
pm and 3 am tonight. The gusty downslope winds will bring warming
temperatures as high as 90 degrees along with lowering humidities,
with potential brief critical fire weather conditions late this
afternoon and evening. For interior areas not under a Red Flag
Warning, elevated fire danger will continue through tonight.
For the Sage Fire region in the Santa Clarita Valley, gusty
southwest to west winds will continue through early evening. Winds
will shift to the northwest to north later this evening into the
overnight hours, especially across the ridgetops where gusts up to
30 mph can be expected.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT Monday For zones
39-52. (See LAXNPWLOX).
Wind Advisory in effect until 6 AM PDT Monday For zones
53-54. (See LAXNPWLOX).
Red Flag Warning in effect until 6 AM PDT Monday For zones
252>254. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday For
zones 645-650. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Monday For zones
670-673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Hall
FIRE...Gomberg
AVIATION...KJ
MARINE...Smith
SYNOPSIS...Hall
weather.gov/losangeles
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1041 PM PDT SUN JUL 10 2016
.SYNOPSIS...A quiet weather pattern is forecast to persist
through the week with temperatures warming back to near seasonal
averages by midweek. Cooling is then forecast for next weekend.
&&
.DISCUSSION...As of 9:00 PM PDT Sunday...Winds are diminishing
now, though still locally strong windiest portions of the coast.
Northwest winds have been continuing to gust to near 45 mph both on
top of the bluff out at Pt Reyes at the Pt Sur Lightstation on the
Big Sur coast. The mixing from these winds, in conjunction with a
significantly drier air mass moving in aloft, have resulted in
clear skies this evening, not only across all of our land areas
but all of our marine waters as well. Current fog product
satellite imagery shows the nearest patches of stratus are
presently about 175 miles west of the San Mateo County coast.
Based on new 00Z NAM boundary layer RH output and 02Z HRRR 0-0.5
km mixed layer RH, do expect stratus to fill back in over the
coastal waters at least south of around the Golden Gate -- but
with much more limited redevelopment either farther north along
the coast or into San Francisco Bay. In this regard have also
noted that the KACV to KSFO SLP gradient is now up at 6.7 mb as
surface high pressure builds inland through Oregon and far
northern California.
Have therefore made some minor updates to the forecast package to
diminish low cloud and patchy fog coverage overnight into Monday
morning. Otherwise present forecasts look good.
.PREVIOUS DISCUSSION...A gradual warming trend is forecast through
midweek as an upper ridge currently centered over the southern
Great Plains expands to the west and north. Inland temperatures
will warm back to near normal by Tuesday and some inland valleys
are forecast to warm a bit above normal by Wednesday. Meanwhile,
the marine layer will become better established over the next few
days as the low levels become more stable and onshore flow
persists. So, expect more widespread night and morning coastal low
clouds and fog by Tuesday and Wednesday, mainly in coastal areas.
Increased marine layer clouds will mean coastal areas will see
little, if any, warming as we move towards midweek.
The longer range models agree that the upper ridge will weaken
late in the work week and into next weekend as a trough drops
into the Pacific Northwest. This will bring about modest cooling
beginning on Friday or by Saturday at the latest.
&&
.AVIATION...As of 10:30 PM PDT Sunday...Surface high pressure
ridge is building into the Pacific Northwest coast. This is
increasing the n-s gradient which is a sign of drier air over the
area. As a result VFR is expected in the SFO Bay Area overnight.
Some clouds willl form along the coast from the San Mateo coast
south which could get into MRY and SNS by morning.
Vicinity of KSFO...VFR. Westerly winds 20-25 kt through 04z.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR 13Z-17Z.
&&
.MARINE...as of 8:28 PM PDT Sunday...Surface high pressure off
the California coast extends into the Pacific Northwest coast.
This will maintain gusty northwest winds through Monday night.
Thermal low pressure will build over Southern California by
midweek resulting in lighter winds over the coastal waters.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...Rough Bar Advisory for SF Bar
&&
$$
PUBLIC FORECAST: Blier/Dykema
AVIATION: W Pi
MARINE: W Pi
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Area Forecast Discussion
National Weather Service Denver/Boulder CO
935 PM MDT TUE JUL 12 2016
.UPDATE...
Issued at 935 PM MDT Tue Jul 12 2016
Storms have generated on the back edge of outflow. As a result,
see isolated storm development as far west as the eastern portions
of the Denver Metro area so far. Will adjust thunderstorm chances
accordingly and also delay their departure overnight.
UPDATE Issued at 801 PM MDT Tue Jul 12 2016
As expected...a few weak thunderstorms have developed just north
of the palmer divide and are drifting east. there is an apparent
weak upper trough seen on water vapor imagery that is moving
through central wyoming and northwest colorado...as a result these
storms should spread into kansas by 11pm. These storms may produce
some small hail.
Overall the forecast is in good shape...no changes.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 337 PM MDT Tue Jul 12 2016
Warm temperatures and low humidities have returned this afternoon,
especially in the mountain areas. Moderate westerly flow aloft has
mixed down to the surface in the mountains with the warm
temperatures. On the plains...showers have failed to materialize
up to this point, but the HRRR shows a few showers over the Palmer
Divide in the next few hours. This will be the only areas of
weather this evening. For tomorrow...more of the same weather is
expected as westerly flow aloft continues. Temperatures are
expected to be a few degrees warmer under the persistent warm
ridging over the region. Medium range models do not generate any
shower activity tomorrow afternoon, but we will wait to see if the
shorter range models generate showers tomorrow morning.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 337 PM MDT Tue Jul 12 2016
The strong Westerly flow aloft will shift a bit more Northwesterly
for Thursday and Friday. This will open the door for some cooler
temperatures and weak surges moving into Northeast Colorado.
Moisture levels will also increase across the plains leading to a
better chance for showers and thunderstorms by late Thursday
afternoon and again for Friday. There are some differences showing
up in model solutions with the NAM being the cooler and wetter
model while GFS solution is drier and warmer. At this time will go
more in the middle road and see how things evolve as the week
goes along. If in fact the NAM is correct may even see severe
storms on the plains given higher dewpoints and CAPE values
upwards of 2000j/kg on the plains and modest shear.
The flow again shifts back more Southwest over the weekend as the
broad high pressure builds back over the Southern High plains.
Drier and warmer temperatures return under the SW flow. Model
trends by early next week indicate the High pressure aloft will
rebuild further North into the Central portion of the country
which may begin to steer moisture back into Colorado from the
Southwest.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 935 PM MDT Tue Jul 12 2016
Thunderstorm in the vicinity of KDEN that developed along outflow
boundary will likely move off to the east toward 05Z. Otherwise
VFR conditions and winds transitioning to normal drainage patterns
expected.
&&
.FIRE WEATHER...
Issued at 337 PM MDT Tue Jul 12 2016
Extremely low relative humidities are being observed in North and
Middle Park along with breezy conditions. Will let the Red Flag
Warning continue through expiration at 8 PM.
For Wednesday...much the same conditions are expected as moderate
zonal flow aloft continues with temperatures maybe a degree or
two warmer. Fire behavior this afternoon has been more limited
than yesterday, but may pick up again tomorrow. Will issue a Fire
Weather Watch for North, Middle and South Parks, along with the
northern Front Range Foothills.
&&
.BOU Watches/Warnings/Advisories...
Fire Weather Watch from Wednesday morning through Wednesday
evening for COZ211-213>215-217.
&&
$$
UPDATE...Barjenbruch
SHORT TERM...Dankers
LONG TERM...Entrekin
AVIATION...Barjenbruch
FIRE WEATHER...Dankers
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
640 PM CDT TUE JUL 12 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Wednesday)
Issued at 328 PM CDT TUE JUL 12 2016
Water vapor imagery showing upper wave rotating north into central
Canada around an upper low over southern Saskatchewan, with another
wave forming to its west. Overnight convective complex had
dissipated over southeastern Kansas and southwestern Missouri with
southeast winds returning early in the day. This has allowed rather
moist air to return and status to be prevalent for most areas early
this afternoon. Weak surface trough remains over the area from
southwest to northeast.
Precipitation chances remain the main challenge through Wednesday
afternoon. Surface-based convection looking more and more unlikely
this afternoon and evening with destabilization retarded by the
stratus. A weak mid-level wave appears to have initiated a few
elevated showers in central portions of the area and isolated
activity seems possible into the late afternoon as this moves off.
The more active period should come in the late evening to overnight
hours as the low level jet increases resulting in decent convergence
and isentropic lift around 850mb. With little other focusing/forcing
mechanism and little model agreement, have kept pops in chance
range, highest in east where the best moisture/upglide is suggested.
Elevated shear and CAPE values could support some severe wind and
hail. Thickness and Corfidi vectors suggest activity propagating
southeast with time and have followed along in the overnight and
early morning hours. Next front still looking to enter the area
from the northwest in the late afternoon. Expect better insolation
ahead of this front for more potential for storms with it though
mid level capping aloft does look to increase somewhat. Will keep
chance pops mainly in the north. Severe weather potential exists
here too with wind and hail the main issues in steep mid and low
level lapse rates.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 328 PM CDT TUE JUL 12 2016
Wednesday Night through Friday...
Speed and position of the incoming front for Wednesday evening into
the overnight hours has some timing differences both in synoptic
models and mesoscale propagation, but for the most part sweeps the
front and associated convection across the area in this time period.
Locally heavy rainfall will be possible but difficult to pinpoint
depending on the speed of the boundary, but should be noted as a
hazard. Atmosphere looks to have a chance to heat up and destabilize
before the boundary comes in, and as such these storms may bring
damaging winds or hail as a hazard as well.
Could likely see a break between overnight storms and
redevelopment on Thursday late, before once again being reignited
along and to our south as the low level jet increases. Both
Wednesday night and Thursday night models also indicate shortwave
trofs moving over the frontal boundary and aiding in convective
development. Think the front will be shifted southward into Friday
as high pressure moves into the Central Plains from the northeast,
and have diminished and shifted chances to the south as a result.
Highs Thursday are forecast near 90, and a few degrees cooler on
Friday behind the front in the middle 80s.
Friday Night through Tuesday...
Shortwaves in the synoptic flow leave the weekend in another
unsettled pattern. Chances for storms are seen Friday night through
Sunday night, although Sunday looks like dry periods will be
possible during the afternoon and evening. Monday and Tuesday look
to be dry as an upper level high pressure system moves over the
Central Plains. As for temperatures through the period, highs will
range from the mid-80s to lower 90s, with seasonable low
temperatures near the lower 70s forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 630 PM CDT TUE JUL 12 2016
For the 00z TAFs, MVFR cigs have improved to VFR cigs and should
remain VFR through the period. The main area of uncertainty is on
the timing and location of scattered storms. Latest short-range
models show KTOP/KFOE having the best potential, so have a TEMPO
group for the overnight hours. However, have kept just VCTS for
KMHK due to uncertainty in how far west storms will develop. Any storms
that develop late tonight and overnight should diminish by
Wednesday morning. There is the potential for additional scattered
storms to develop by late Wednesday afternoon, but confidence is
not high enough to warrant a mention in the TAFs at this time.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67/Heller
AVIATION...Hennecke
[top]
Area Forecast Discussion
National Weather Service Goodland KS
510 PM MDT TUE JUL 12 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 141 PM MDT Tue Jul 12 2016
Dry conditions will prevail this afternoon with increasing
cloudiness this afternoon and evening in advance of a fast moving
short wave followed by a warm front. Short term guidance has come
into better agreement at midday as the HRRR and RAP have
increasingly moved toward the NAM12 and SREF solutions. The ARW and
NMM models however, have backed off on precip chances. Overall, I
increased PoPs across the CWA in response to the model guidance
coming into better agreement. The environment will become
increasingly favorable for thunderstorms around or after 00Z in
eastern Colorado, spreading eastward into northwest Kansas as we
head through the evening and overnight. CAPE values will increase
through the afternoon to near 2100 J/Kg as the warm front approaches
with bulk shear at 30kt to 50kt (RAP), and DCAPE in the 400 J/Kg to
1000 J/Kg range. There is a marginal risk of severe thunderstorms
that could include large hail and damaging wind gusts.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 150 PM MDT Tue Jul 12 2016
Low chances for thunderstorms will continue Wednesday night and
Thursday morning in the wake of an earlier cold frontal passage.
Favorable low level upslope combined with weak shortwave trough
aloft will result in limited coverage during those time
periods...but increasing Thursday afternoon and evening with
destabilization. Moderate to strong instability is forecast with
deep layer shear of 40-50kts...an environment conducive to
supercells. Only negative is lack of well-defined synoptic scale
forcing which may limit overall coverage of storms. The wet
pattern continues into Friday with the upper flow becoming more
northwest and possible embedded shortwave trough providing lift.
Afternoon instability not as impressive as Thursday...only
moderate values are forecast...although deep layer shear remains
around 40kts. Severe storms will be possible once again.
Temperatures will be above normal on Wednesday...then below normal
on Thursday and Friday.
Upper ridge will begin to strengthen over the weekend. Other than
some isolated storms Saturday afternoon developing on the higher
terrain of eastern Colorado a hot and dry period will begin for
the region. This will continue through at least Tuesday.
Temperatures will return to the upper 90s/lower 100s by the
beginning of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 510 PM MDT Tue Jul 12 2016
For KGLD and KMCK...vfr conditions expected through the period. A
weather disturbance will interact with a frontal boundary to
produce a slight chance for thunderstorms to both KGLD and KMCK in
the 03z-10z and 07z-11z timeframes respectively this evening
through overnight. As the storms develop and short term model
guidance comes in further refinements will be made. For the
daylight hours Wednesday little if any clouds expected. Winds
begin the period from the southeast around 10kts becoming light
and variable in the 07z-13z timeframe. From 14z through the rest
of the taf period winds shift to the northwest then north and
northeast at speeds around 10kts or so with some higher gusts.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...TL
LONG TERM...024
AVIATION...99
Area Forecast Discussion
National Weather Service Pueblo CO
401 AM MDT WED JUL 13 2016
.SHORT TERM...(Today and tonight)
Issued at 344 AM MDT Wed Jul 13 2016
Currently...
MCS over nw KS continues to move E-SE. Outflow boundary has pushed
south and was approaching Kiowa NE Kiowa county at 3 am. Elsewhere
across the region...Clear skies dominated. Temps were mild...with
values ranging mainly in the 70s across most of the plains...and 40s
and 50s in the valleys.
Today...
Outflow boundary will likely make it south and westward and sfc flow
across the plains will likely become upslope by this afternoon.
Expect dry and hot conditions over the district today. It will also
likely remain dry...however guidance does hint at some light
convective precip possibly developing along the s mtns late in the
day. For now...my confidence is low in this happening and do not
have any precip fcst in the NDFD...although have 4-7% pops over the
S mtns and plains.
It will be very warm today as max temps will approach 100 over the
plains...especially along the US-50 corridor from Canon City
eastward to KS.
As for fire weather...no hilites have been issued...although near
critical fire weather conditions will occur. RH values will be quite
low across all of the region with many locations reaching min RH
values below 10%. These low values include the Hayden Pass fire
area. Winds on the other hand will be relatively low...with most
values in the 5 to 15 mph range. The only exception to this will be
along the Central mtn tops were a few gusts will approach 30 mph
during the afternoon. I do not expect any widespread significant
gusts over the Hayden Pass fire.
tonight....
A slightly better chance of precip will be possible although
confidence is low that it will actually happen. I have no QPF
mentioned (pops less than 10%)...but I cannot rule out an isold TSRA
late this evening across the plains and possibly adj southern mtns.
The best chance will be over the Palmer Dvd region late this evening
and during the early morning hours.
Oncoming shifts will have to monitor hi-res model trends regarding
increasing/decreasing pops over the region for tonight. /Hodanish
.LONG TERM...(Thursday through Tuesday)
Issued at 344 AM MDT Wed Jul 13 2016
Not much change to the forecast thinking through the extended
period with low ensemble spreads and consistency among the
operational solutions.
Thursday and Friday...flat high pressure will be centered over the
desert southwest with westerly zonal flow with embedded energy
moving across Colorado is forecast for late in the week. A cold
front will have backed west across the eastern plains by Thursday
morning advecting moisture along with easterly upslope flow over
the plains. This, combined with energy moving across the region,
will allow for shower and thunderstorm development by Thursday
afternoon. Expect initiation over the eastern mountains, spreading
east into the I-25 corridor during the late afternoon and evening
hours, before shifting east into western Kansas by Friday morning.
Given the moisture, locally heavy rainfall will be possible, and
burn scars will need to be monitored for flash flooding. In
addition, modest instability and shear may allow for one or two
stronger storms with gusty outflow winds and sub-severe hail.
Models continue to differ on Friday. The GFS and ECMWF have
similar solutions, with the next disturbance dropping southeast
across the far eastern plains Friday afternoon and evening. Both
solutions develop an MCS over northeast Colorado, and drop it
southeast into western Kansas, clipping our far eastern plains.
The NAM however, has this disturbance further west with enhanced
upslope flow across the plains leading to more widespread shower
and thunderstorm activity across the area. Given the model
differences, have low pops across the whole area for Friday
afternoon and evening. Locally heavy rainfall, gusty outflow winds
and small hail will all be possible, especially if a MCS does
develop over the far eastern plains.
Temperatures will be a bit cooler Thursday and Friday with
generally upper 80s expected across the lower elevations.
Saturday through Tuesday...the upper level pattern will begin to
amplify this weekend into early next week. An upper trough is
forecast to develop over the Pacific northwest, while the desert
southwest high pressure builds northward into the central plains.
This will bring increasing southwesterly flow aloft to southern
Colorado. Expect a drying and warming trend as the pattern
evolves. Limited moisture and weak steering flows will keep
diurnally driven showers and thunderstorms over the higher terrain
with little movement. Lightning over the mountains will need to be
monitored, as fuels are critical and wetting rains are not likely
to be widespread under the upper pattern.
Temperatures will warm rapidly this weekend given the enhanced
mixing with most areas across the plains reaching back into the
upper 90s to lower 100s. Mozley
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 344 AM MDT Wed Jul 13 2016
VFR conditions expected at COS, PUB and ALS over the next 24 hours.
Winds will be diurnally driven. There is a very low chance that an
isold tsra could affect the COS and PUB taf sites this evening...but
the probability of this happening is very low.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOZLEY
AVIATION...HODANISH
[top]
Area Forecast Discussion
National Weather Service Denver/Boulder CO
359 AM MDT WED JUL 13 2016
.SHORT TERM...(Today and tonight)
Issued at 355 AM MDT Wed Jul 13 2016
Isolated strong storms finally exiting the far northeast corner of
the state in the pre-dawn hours. After that, expect mostly clear
skies through most of the day. Weak push from the north will bring
ever so slight cooling in the low levels on the plains so think
highs today may end up similar or just a degree warmer than those
observed yesterday, rather than a few degrees warmer as earlier
anticipated. Thunderstorm chances look practically nil during the
day, with only a slight chance near the Palmer Divide area toward
evening. That chance could expand on the eastern plains later this
evening into the overnight hours depending on potential for yet
another moisture surge/theta-e advection similar to what occurred
last night. Will have some low PoPs on the plains through the
entire night with weak Q-G lift slowly increasing.
.LONG TERM...(Thursday through Tuesday)
Issued at 355 AM MDT Wed Jul 13 2016
A 70-80 knot zonal flow up around 300mbs late Wed night gradually
shifts to more of a northwest component but with less strength as
heights rise over the Great Basin. The shift in flow transports
cooler air aloft down from Montana consequently resulting in
cooler sfc temperatures for the CWA on Thursday. The cooling
actually appears to begin late on Wednesday with passage of a weak
backdoor cold front. Model temperature guidance indicates a 3-5
deg f cool down from the day before...with most of the cooling
will be felt east of the mtns. Through the day bndry layer flow
on the plains transitions from northeasterly to southeasterly by
afternoon which advects higher theta-e air up into eastern
portions of the CWA...increasing the chance for convection...
particularly during the late afternoon and early evening hours
with the passage of the weak shortwave trough. NAM indicates sfc
based CAPES in the 2000-2500 j/kg range across Washington...Morgan...
Logan...ern Weld and Sedgwick counties along a wind shear axis.
GFS CAPES not as great and its best CAPES do not show up until
evening up along the Wyoming border with a stiff southeast wind.
Both models indicate the best likelihood for measurable precip
across eastern and southeastern sections of the CWA during the
evening hours when dewpt and PW values will be at their highest.
Could see storms linger well into the night across the eastern
fringe of the CWA. The risk of severe weather appears low although
an isolated t-storm or two could end up producing large hail and
heavy rainfall. The high country appears to remain dry on
Thursday...although the southern Front Range foothills and South
Park could see a few late day t-storms bubble up with stg
afternoon heating and a sely upslope flow. Otherwise...cooler
temperatures...higher RH and lighter winds should lessen the
wildfire danger in the high country.
By Friday...the upper ridge building out west moves a bit closer
which enhances the northwest flow aloft. However winds at low levels
differ in the models. GFS and ECMWF boundary layer winds east of the
mtns are predominately s-sely in direction throughout the day.
While the NAM starts out with sly winds in the morning then shift
to northerly winds in the afternoon creating a zone of convergence
on the plains which could act as a focus for thunderstorm
formation. Model max temperatures differ quite a bit on Friday.
The NAM temps are as much as 5-10 deg f lower than those offered
by the GFS and ECMWF. For now will use a blend of the models to
come up with Fri temps. If the NAM is correct the plains could see
a stormy day on Friday.
Saturday and beyond...upper ridge is progged to move east over the
state on Saturday and Sunday warming temperatures...lowering
humidity levels and reducing the chance of the t-storms. Should see
high temps return to the low/mid 90s at lower elevations. By
Monday...models show the upper ridge slipping east of the state
placing the CWA under a very warm and mostly dry southwest flow
aloft. May still see a few late day t-storms fire mainly over and
near the higher terrain as moisture begins to creep northward from
the Desert Southwest. By Tuesday...latest model runs show hints of
the American monsoon gaining strength over the desert Southwest.
Some of this moisture could spread as far north over our northern
mtns thereby increasing the chance of afternoon and evening
t-storms.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 355 AM MDT Wed Jul 13 2016
VFR conditions will persist through Thursday morning. Winds are
starting the day more northerly behind a weak surge early this
morning. Trend should be toward an anticyclonic wind pattern with
northeast to eventually southeast winds around 10 knots by
afternoon for the Denver metro area airports including KDEN.
Thunderstorm chance at or less than 10 percent, with slightly
better chances farther east including the northeast and southeast
Denver approach gates 00Z-12Z.
&&
.FIRE WEATHER...
Issued at 355 AM MDT Wed Jul 13 2016
Another very warm and dry day shaping up with the continued
westerly flow. Afternoon humidities are expected to drop into the
10 to 15 percent range over most of the forecast area...elevating
fire danger. Only locations that should experience critical wind
conditions with frequent gusts 25 mph or more in conjunction with
the low humidity would be North Park and Middle Park, the Mount
Zirkel Wilderness area including the Beaver Creek Fire, and the
northern Front Range Foothills mainly near the Wyoming border.
Have upgraded the Fire Weather Watch to a Red Flag Warning there.
Conditions should improve rather quickly early this evening as
winds subside.
&&
.BOU Watches/Warnings/Advisories...
Red Flag Warning from 10 AM this morning to 8 PM MDT this
evening for COZ211-213-215-217.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Baker
AVIATION...Barjenbruch
FIRE WEATHER...Barjenbruch
[top]
Area Forecast Discussion
National Weather Service Grand Junction CO
328 AM MDT WED JUL 13 2016
.SHORT TERM...(Today through Thursday)
Issued at 249 AM MDT Wed Jul 13 2016
Yes, another day of dry and hot conditions with some afternoon
clouds thrown in for good measure. Zonal flow remains in place as
we`re sandwiched between high pressure to our south and the more
active northern states. Guidance suggesting another breezy day
today especially along the Wyoming border where gusts of 25 to
30 mph look to be common. Further south, some higher gusts will
be felt but does not look as widespread so cancelled the fire
weather watch for zone 202 while upgrading the watch to a Red Flag
Warning for zone 200.
Thursday, more of the same as high temperatures will be a few
degrees warmer than today. Some afternoon breezes are expected but
not as high as we`ve seen lately.
.LONG TERM...(Thursday through Tuesday)
Issued at 330 PM MDT Tue Jul 12 2016
Conditions will remain relatively quiet, dry and warmer than
normal through early next week. Flow aloft will shift from the
west on Friday to the southwest this weekend and into early next
week. Isolated thunderstorms may arrive as early as Monday with
better chances Tuesday. Latest model data suggests less moisture
available on Tuesday than in earlier runs so coverage may be
reduced.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 249 AM MDT Wed Jul 13 2016
VFR conditions continue for the next 24 hours. Expect some breezy
afternoon winds.
&&
.FIRE WEATHER...
Issued at 330 PM MDT Tue Jul 12 2016
The fire weather watch for zone 202 has been cancelled with this
morning`s package. While some breezes will reach criteria, they
don`t look widespread enough to issue any warnings. However, for
zone 200, much of the area looks to have gusts between 25 to 30
mph while humidities will drop below 15 percent. The watch for
that area has been upgraded to a Red Flag Warning from noon
through 8PM. Day shift folk will need to keep an eye on 202 to see
if winds become more widespread than originally thought.
&&
.GJT Watches/Warnings/Advisories...
CO...Red Flag Warning from noon today to 8 PM MDT this evening for
COZ200.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...NL
AVIATION...TGR
FIRE WEATHER...TGR
Area Forecast Discussion
National Weather Service Pueblo CO
1134 PM MDT TUE JUL 12 2016
.UPDATE...
Issued at 930 PM MDT Tue Jul 12 2016
Removed POPS from the forecast tonight based on the HRRR, although
the HRRR does show the potential for storms to get near Kiowa
county so will have to keep an eye on that area.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 327 PM MDT Tue Jul 12 2016
...A Few Possible Storms on the Plains Tonight...
Current water vapor imagery and upper air analysis continues to
indicate moderate westerly flow aloft across the region with a minor
embedded short wave translating across the northern Great Basin and
Northern Rockies at this time. At the surface, induced lee low
between LHX and TAD has kept low level moisture and easterly to
southeast winds in place across most the eastern plains through the
early afternoon, with drier westerly winds across the higher terrain
starting to mix out west of the I-25 corridor at this time. The
drier westerly flow can also be seen with increased activity on the
Hayden Pass Wildfire...with its plume now evident on KPUX radar into
the afternoon.
For this evening, added pops across the Palmer Dvd and kept current
pops across the far southeast plains, as lastest model runs
indicating the potential for a few storms developing along moisture
gradient as induced surface low lifts out across the southeast
plains this evening and into southwestern Kansas overnight. SPC meso
analysis indicating 1000-2000 J/KG of CAPE along with some CIN
across the plains at this time. If storms can develop, there will be
enough shear to support isolated supercells, producing large hail
and strong winds, along with locally heavy rainfall.
For the rest of tonight and Wednesday, dry westerly flow aloft to
persist across the region with the embedded short wave translating
east across the Northern Rockies and into the Northern High Plains.
Should see breezy westerly flow persisting across the higher terrain
tonight, keeping temperatures up and dew pts low supporting poor RH
recovery, especially along and west of the I-25 corridor. This will
likely keep area wildfires more active overnight than previous
nights.
Flow aloft relax a tad through the day tomorrow, though will still
see breezy westerly winds across the higher terrain through the
afternoon. This supports some marginal critical fire weather
conditions, mainly across the central mountains, though this does
not look widespread enough to support a red flag warning at this
time. Temperatures to be at or slightly warmer than today,
especially across the eastern plains, where could see highs pushing
the century mark once again.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 327 PM MDT Tue Jul 12 2016
Hot Weather with some rain opportunities...
Wednesday night...northern shortwave will allow some cooler air to
infiltrate the eastern plains during the night, and moister east
flow pushing up against the eastern mountains late. Models not
indicating enough moisture or lift to produce any measurable rainfall
though.
Thursday and Friday...moist low level upslope flow across the
plains and I-25 corridor will persist Thursday into Friday, with
the possibility being greater for rainfall on the Hayden Pass
wildfire Friday afternoon and evening. A series of shortwaves
rippling through the westerly flow aloft will help in the
development of showers and storms across the CWA during this
period. There will be the potential for a couple marginally severe
storms each afternoon and evening from the eastern mountains into
the plains. Also, locally heavy rainfall will be possible and
eastern burn scars will need to be monitored for flash flooding.
Friday night into Saturday...models show a shortwave causing
showers and storms mainly north of our CWA, which could morph
into an MCS. Current trends are for this feature to be north of
our CWA, but, even so, it would send an outflow into our plains,
keeping the atmosphere on the moist side to the eastern mountains
over the weekend and into early next week.
Saturday through Monday...the upper level pattern will transition
to a trough along the west coast and high pressure across the
great plains. The resultant southwest flow aloft, along with
somewhat limited moisture and weak disturbances will yield
afternoon and evening isolated convection.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1133 PM MDT Tue Jul 12 2016
VFR conditions are expected across the TAF sites during the next
24H. A few patchy areas of stratus could develop across the far
eastern plains overnight, but will not impact KPUB and KCOS. Dry and
hot conditions are expected Wednesday with breezy winds gusting up
to 20 knots developing across the terminals during
afternoon. ~Lukinbeal
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...28
SHORT TERM...TM/MW
LONG TERM...TM/MW
AVIATION...MOORE/LUKINBEAL
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
302 AM CDT WED JUL 13 2016
.SHORT TERM...(Today and Tonight)
Issued at 301 AM CDT WED JUL 13 2016
A complex of storms was located across northeast CO and northwest
KS early this morning. This complex of thunderstorms will begin to
forward propagate to the east and southeast along a deeper moisture
and instability axis that extends from south central KS and northwest
OK, northwest into northeast CO. If this complex of storms becomes
severe with damaging wind gusts as it moves southeast across west
central KS it may move into the southwest and southern counties of
the CWA after 12Z with the potential for severe wind gusts and heavy
rainfall generally south of I-70. The 00Z Nam model keeps the
complex southwest and south of the CWA during the morning hours. The
WRF solutions move the complex of storms across the southwest
counties after 12Z, then across the southern counties of the CWA
through the mid and late morning hours. The GFS moves the complex
due east across southern NE which clips the northern counties of the
CWA. The experimental HRRR moves the complex of storms east along
and just south of I-70 from 12Z through 17Z. The best chance for
strong to severe winds from this complex of thunderstorms will be
along and south of the nearly stationary outflow boundary which
extends along I-35 from south of KC, west-southwest to north of
Emporia, then due west. south of Salina, to north of Great Bend. If
this boundary drifts northward then there may be more of chance for
stronger winds up to I-70. Also, during the mid morning hours across
east central KS the boundary layer may mix deep enough with steep
lapse rates from 850mb to the surface for stronger winds aloft to be
entrained to the surface, if the complex of storms maintains it
intensity as it shifts east-southeast across the southern counties
of the CWA.
Wednesday afternoon through Tonight, the complex of storms will move
east-southeast across western MO. The outflow boundary may push
south of the CWA but should wash out across southeast KS. A weak
front will push southeast across the CWA and thunderstorms may
redevelop along and south of the weak surface front. The WRF and
experimental HRRR solutions show the surface outflow boundary
maintaining itself through the afternoon hours along and southeast
of I-35 where a line of storms or a complex of storms will develop
and push southeast of the CWA during the early to mid evening hours.
The NAM and GFS develop thunderstorms farther north across northeast
KS along the front during the afternoon hours, then forms a complex
of thunderstorms that tracks southward across east central KS during
the evening hours. At this time, I`m leaning more towards the meso
scale models. Any complex of thunderstorms may produce severe wind
gusts and heavy rainfall. Initial isolated to scattered
thunderstorm development may produce large hail. The NAM model
increases MLCAPE to over 5,000 J/KG this afternoon, which may be a
bit over done but if we see insolation this afternoon with dewpoints
in the mid 70s, we could see MLCAPES in the 3,000 to 4,000 J/KG
range. It will depends on where the storms develop to which areas
will have the best chances for severe thunderstorms during the
afternoon and evening hours.
Highs Today will depend on the track and timing of the mid and late
morning thunderstorm complex and if the cloud cover will scatter out
during the afternoon hours. If we see insolation this afternoon most
areas could see lower to mid 90s. If the thunderstorm complex moves
across the southern counties a few hours slower then east central KS
may keep cloud cover through the afternoon hours and highs may only
reach the mid and upper 80s. I think we will see break in the cloud
cover later this afternoon and have went with highs in the lower 90s
across the eastern and northern counties with mid 90s across the
southeast counties of the CWA.
.LONG TERM...(Thursday through Tuesday)
Issued at 301 AM CDT WED JUL 13 2016
Tomorrow the lingering frontal boundary should be located somewhere
in east central or southeast KS. The consensus is that it may be
located just south of the forecast area especially with storm
outflows pushing southward and reinforcing the boundary near the
OK/KS state line. The 12 km NAM is aggressive with developing an MCS
within the upslope flow over the high plains, and moving that MCS
along this boundary during the day Thursday. The WRF solutions
develop diurnal storms along the boundary in southeast KS. The other
larger scale models do not support this MC, and instead show
isolated to scattered storms developing late afternoon due to peak
heating and low level convergence similar to the WRF. There is a
chance this activity remains further south depending on the boundary
location. Given the uncertainty with morning showers and storms it
is difficult to determine if the environment will become favorable
for strong to severe storms Thursday afternoon. Instability if
realized should support a damaging wind threat and possibly hail. An
MCS during the afternoon would pose a wind threat as well.
A shortwave may also move across KS in the late evening into the
overnight and possibly support an MCS that could clip the far
southern forecast area. The track of this wave keeps gradually
shifting southward. Northwest flow aloft continues with subtle waves
moving over the region. Return flow will develop across the area
bringing moisture back northward. This pattern will favor possible
MCSs especially during the overnight with the strengthening of the
low level jet. This scenario may occur Friday night, but is too far
out to nail down exact timing and location. Mid level ridge begins
to build over KS, which pushes the storm track further north. One
more cold front may try to reach northern KS Sunday night and
Monday, but may only bring a small chances for storms to the area.
Beyond that looks rather dry and hot as the ridge centers overhead
into late week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1157 PM CDT TUE JUL 12 2016
For the 06z TAFs, the main focus is on the potential for scattered
storms near the TAF sites. The initial scattered storms should be
focused predominantly across east central Kansas overnight,
potentially impacting KTOP/KFOE so have a tempo group for TSRA.
Short-range models have been suggesting that storms across far
northwest KS may sustain themselves and advance into north central
KS by Wednesday morning, so added a tempo group for KMHK. A break
from thunderstorms is expected during the day before another round
of storms is expected to impact the TAF sites sometime during the
late afternoon through evening hours on Wednesday.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Sanders
AVIATION...Hennecke
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1200 AM CDT WED JUL 13 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Wednesday)
Issued at 328 PM CDT TUE JUL 12 2016
Water vapor imagery showing upper wave rotating north into central
Canada around an upper low over southern Saskatchewan, with another
wave forming to its west. Overnight convective complex had
dissipated over southeastern Kansas and southwestern Missouri with
southeast winds returning early in the day. This has allowed rather
moist air to return and status to be prevalent for most areas early
this afternoon. Weak surface trough remains over the area from
southwest to northeast.
Precipitation chances remain the main challenge through Wednesday
afternoon. Surface-based convection looking more and more unlikely
this afternoon and evening with destabilization retarded by the
stratus. A weak mid-level wave appears to have initiated a few
elevated showers in central portions of the area and isolated
activity seems possible into the late afternoon as this moves off.
The more active period should come in the late evening to overnight
hours as the low level jet increases resulting in decent convergence
and isentropic lift around 850mb. With little other focusing/forcing
mechanism and little model agreement, have kept pops in chance
range, highest in east where the best moisture/upglide is suggested.
Elevated shear and CAPE values could support some severe wind and
hail. Thickness and Corfidi vectors suggest activity propagating
southeast with time and have followed along in the overnight and
early morning hours. Next front still looking to enter the area
from the northwest in the late afternoon. Expect better insolation
ahead of this front for more potential for storms with it though
mid level capping aloft does look to increase somewhat. Will keep
chance pops mainly in the north. Severe weather potential exists
here too with wind and hail the main issues in steep mid and low
level lapse rates.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 328 PM CDT TUE JUL 12 2016
Wednesday Night through Friday...
Speed and position of the incoming front for Wednesday evening into
the overnight hours has some timing differences both in synoptic
models and mesoscale propagation, but for the most part sweeps the
front and associated convection across the area in this time period.
Locally heavy rainfall will be possible but difficult to pinpoint
depending on the speed of the boundary, but should be noted as a
hazard. Atmosphere looks to have a chance to heat up and destabilize
before the boundary comes in, and as such these storms may bring
damaging winds or hail as a hazard as well.
Could likely see a break between overnight storms and
redevelopment on Thursday late, before once again being reignited
along and to our south as the low level jet increases. Both
Wednesday night and Thursday night models also indicate shortwave
trofs moving over the frontal boundary and aiding in convective
development. Think the front will be shifted southward into Friday
as high pressure moves into the Central Plains from the northeast,
and have diminished and shifted chances to the south as a result.
Highs Thursday are forecast near 90, and a few degrees cooler on
Friday behind the front in the middle 80s.
Friday Night through Tuesday...
Shortwaves in the synoptic flow leave the weekend in another
unsettled pattern. Chances for storms are seen Friday night through
Sunday night, although Sunday looks like dry periods will be
possible during the afternoon and evening. Monday and Tuesday look
to be dry as an upper level high pressure system moves over the
Central Plains. As for temperatures through the period, highs will
range from the mid-80s to lower 90s, with seasonable low
temperatures near the lower 70s forecast.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1157 PM CDT TUE JUL 12 2016
For the 06z TAFs, the main focus is on the potential for scattered
storms near the TAF sites. The initial scattered storms should be
focused predominantly across east central Kansas overnight,
potentially impacting KTOP/KFOE so have a tempo group for TSRA.
Short-range models have been suggesting that storms across far
northwest KS may sustain themselves and advance into north central
KS by Wednesday morning, so added a tempo group for KMHK. A break
from thunderstorms is expected during the day before another round
of storms is expected to impact the TAF sites sometime during the
late afternoon through evening hours on Wednesday.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67/Heller
AVIATION...Hennecke
Area Forecast Discussion
National Weather Service Dodge City KS
1200 AM CDT WED JUL 13 2016
...Updated Aviation...
.SHORT TERM...(This evening through Wednesday)
Issued at 237 PM CDT Tue Jul 12 2016
An area of low pressure will slide westward along the KS/OK
border this evening reaching far southwestern Kansas by sunrise
tomorrow. Meanwhile, an associated warm front will shift from
central Kansas tonight into western Kansas by sunrise tomorrow.
Partly cloudy skies and dry conditions are expected with the
exception of across northern Kansas where a slight chance of
thunderstorms will be possible after midnight. The frontal
boundary slides back east tomorrow do to an upper level
disturbance moves into the area. A few thunderstorms may form
along this boundary late tomorrow afternoon into tomorrow evening,
mainly across central Kansas. Winds will generally be from the
southeast tonight shifting to more of a northerly direction
tomorrow as the frontal boundary moves through the CWA. As for
temperatures, lows tonight look to range from the mid 60s across
eastern Colorado to mid 70s across south central Kansas. Highs
tomorrow are expected to reach into the upper 90s with some areas
along the KS/OK border reaching around 100 degrees.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 323 PM CDT Tue Jul 12 2016
Scattered thunderstorms are expected Thursday into Friday as
upper level disturbances moves through the area with an upslope
easterly component of the wind at the surface. A few storms
Thursday afternoon may become severe with large hail and damaging
winds being the main concern. Moisture will be abundant in the
lower levels of the atmosphere creating an increase of cloudiness
across western Kansas. Thunderstorms chances look to be confined
across central Kansas Saturday morning with decreasing cloudiness
as the day progresses. Models then suggest the upper level high
across the Southern United States to build and shift northward
into the remainder of the Plains. This will bring a drier weather
pattern to western Kansas into at least the first part of next
week. As for temperatures, highs look to be in the 90s Thursday
then upper 80s to lower 90s Friday. A warming trend is expected
this weekend into the first part of next week reaching into the
upper 90s to around 100 degrees by Sunday. Lows look to dip into
the 60s through Friday night then increase into the upper 60s to
lower 70s this weekend into the early part of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1200 AM CDT Wed Jul 13 2016
VFR/SKC expected to prevail through the TAF forecast period.
Thunderstorms over NE Colorado at midnight are forecasted by
NAM/HRRR models to organize into a complex and track SE toward
HYS toward the 09-12z time frame. Have enough confidence in these
solutions to add a convective TEMPO group for HYS starting at 09z.
Otherwise, surface winds through Wednesday will trend NWly and
then NEly behind another weak frontal boundary. Convection
Wednesday afternoon/evening will be isolated at best, with
confidence on aviation impacts low.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 98 69 94 / 10 10 10 40
GCK 68 97 68 92 / 10 10 10 30
EHA 68 100 67 95 / 10 10 10 30
LBL 69 101 69 97 / 10 10 10 30
HYS 69 97 69 89 / 30 20 20 30
P28 75 103 72 97 / 10 20 20 50
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Hovorka_42
LONG TERM...Hovorka_42
AVIATION...Turner
Area Forecast Discussion
National Weather Service Goodland KS
1030 PM MDT TUE JUL 12 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 141 PM MDT Tue Jul 12 2016
Dry conditions will prevail this afternoon with increasing
cloudiness this afternoon and evening in advance of a fast moving
short wave followed by a warm front. Short term guidance has come
into better agreement at midday as the HRRR and RAP have
increasingly moved toward the NAM12 and SREF solutions. The ARW and
NMM models however, have backed off on precip chances. Overall, I
increased PoPs across the CWA in response to the model guidance
coming into better agreement. The environment will become
increasingly favorable for thunderstorms around or after 00Z in
eastern Colorado, spreading eastward into northwest Kansas as we
head through the evening and overnight. CAPE values will increase
through the afternoon to near 2100 J/Kg as the warm front approaches
with bulk shear at 30kt to 50kt (RAP), and DCAPE in the 400 J/Kg to
1000 J/Kg range. There is a marginal risk of severe thunderstorms
that could include large hail and damaging wind gusts.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 150 PM MDT Tue Jul 12 2016
Low chances for thunderstorms will continue Wednesday night and
Thursday morning in the wake of an earlier cold frontal passage.
Favorable low level upslope combined with weak shortwave trough
aloft will result in limited coverage during those time
periods...but increasing Thursday afternoon and evening with
destabilization. Moderate to strong instability is forecast with
deep layer shear of 40-50kts...an environment conducive to
supercells. Only negative is lack of well-defined synoptic scale
forcing which may limit overall coverage of storms. The wet
pattern continues into Friday with the upper flow becoming more
northwest and possible embedded shortwave trough providing lift.
Afternoon instability not as impressive as Thursday...only
moderate values are forecast...although deep layer shear remains
around 40kts. Severe storms will be possible once again.
Temperatures will be above normal on Wednesday...then below normal
on Thursday and Friday.
Upper ridge will begin to strengthen over the weekend. Other than
some isolated storms Saturday afternoon developing on the higher
terrain of eastern Colorado a hot and dry period will begin for
the region. This will continue through at least Tuesday.
Temperatures will return to the upper 90s/lower 100s by the
beginning of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1030 PM MDT Tue Jul 12 2016
KGLD...mvfr/ifr conditions possible from taf issuance through
about 09z-10z with winds from the east-southeast/southeast under
10kts. Short range models insisting that convection currently a
row of counties north of the terminal will move east-southeast or
southeast into axis of elevated instability and possibly producing
near severe/severe thunderstorms with large hail, damaging winds
and locally heavy rainfall to the terminal. They also suggest that
stratus will develop immediately behind the convection for a few
hours producing scattered to broken low cloudiness. After 10z
winds start to veer to the west, north, northeast and east through
the rest of the taf period with some gusts near 20kts possible.
Strato cumulus/cumulus clouds possible during the morning hours
with perhaps some mid clouds during the afternoon and evening.
KMCK...vfr conditions expected through the period. May have
thunderstorms in the vicinity or on top of the terminal in the
08z-10z timeframe with winds light from the southeast. After 10z
winds are similar to KGLD with west then northwest, north,
northeast and east through the rest of the taf period. A few gusts
near 20kts possible. Fair weather cumulus clouds possible during
the daylight and early evening hours.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...TL
LONG TERM...024
AVIATION...99
Area Forecast Discussion
National Weather Service Pueblo CO
401 AM MDT WED JUL 13 2016
.SHORT TERM...(Today and tonight)
Issued at 344 AM MDT Wed Jul 13 2016
Currently...
MCS over nw KS continues to move E-SE. Outflow boundary has pushed
south and was approaching Kiowa NE Kiowa county at 3 am. Elsewhere
across the region...Clear skies dominated. Temps were mild...with
values ranging mainly in the 70s across most of the plains...and 40s
and 50s in the valleys.
Today...
Outflow boundary will likely make it south and westward and sfc flow
across the plains will likely become upslope by this afternoon.
Expect dry and hot conditions over the district today. It will also
likely remain dry...however guidance does hint at some light
convective precip possibly developing along the s mtns late in the
day. For now...my confidence is low in this happening and do not
have any precip fcst in the NDFD...although have 4-7% pops over the
S mtns and plains.
It will be very warm today as max temps will approach 100 over the
plains...especially along the US-50 corridor from Canon City
eastward to KS.
As for fire weather...no hilites have been issued...although near
critical fire weather conditions will occur. RH values will be quite
low across all of the region with many locations reaching min RH
values below 10%. These low values include the Hayden Pass fire
area. Winds on the other hand will be relatively low...with most
values in the 5 to 15 mph range. The only exception to this will be
along the Central mtn tops were a few gusts will approach 30 mph
during the afternoon. I do not expect any widespread significant
gusts over the Hayden Pass fire.
tonight....
A slightly better chance of precip will be possible although
confidence is low that it will actually happen. I have no QPF
mentioned (pops less than 10%)...but I cannot rule out an isold TSRA
late this evening across the plains and possibly adj southern mtns.
The best chance will be over the Palmer Dvd region late this evening
and during the early morning hours.
Oncoming shifts will have to monitor hi-res model trends regarding
increasing/decreasing pops over the region for tonight. /Hodanish
.LONG TERM...(Thursday through Tuesday)
Issued at 344 AM MDT Wed Jul 13 2016
Not much change to the forecast thinking through the extended
period with low ensemble spreads and consistency among the
operational solutions.
Thursday and Friday...flat high pressure will be centered over the
desert southwest with westerly zonal flow with embedded energy
moving across Colorado is forecast for late in the week. A cold
front will have backed west across the eastern plains by Thursday
morning advecting moisture along with easterly upslope flow over
the plains. This, combined with energy moving across the region,
will allow for shower and thunderstorm development by Thursday
afternoon. Expect initiation over the eastern mountains, spreading
east into the I-25 corridor during the late afternoon and evening
hours, before shifting east into western Kansas by Friday morning.
Given the moisture, locally heavy rainfall will be possible, and
burn scars will need to be monitored for flash flooding. In
addition, modest instability and shear may allow for one or two
stronger storms with gusty outflow winds and sub-severe hail.
Models continue to differ on Friday. The GFS and ECMWF have
similar solutions, with the next disturbance dropping southeast
across the far eastern plains Friday afternoon and evening. Both
solutions develop an MCS over northeast Colorado, and drop it
southeast into western Kansas, clipping our far eastern plains.
The NAM however, has this disturbance further west with enhanced
upslope flow across the plains leading to more widespread shower
and thunderstorm activity across the area. Given the model
differences, have low pops across the whole area for Friday
afternoon and evening. Locally heavy rainfall, gusty outflow winds
and small hail will all be possible, especially if a MCS does
develop over the far eastern plains.
Temperatures will be a bit cooler Thursday and Friday with
generally upper 80s expected across the lower elevations.
Saturday through Tuesday...the upper level pattern will begin to
amplify this weekend into early next week. An upper trough is
forecast to develop over the Pacific northwest, while the desert
southwest high pressure builds northward into the central plains.
This will bring increasing southwesterly flow aloft to southern
Colorado. Expect a drying and warming trend as the pattern
evolves. Limited moisture and weak steering flows will keep
diurnally driven showers and thunderstorms over the higher terrain
with little movement. Lightning over the mountains will need to be
monitored, as fuels are critical and wetting rains are not likely
to be widespread under the upper pattern.
Temperatures will warm rapidly this weekend given the enhanced
mixing with most areas across the plains reaching back into the
upper 90s to lower 100s. Mozley
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 344 AM MDT Wed Jul 13 2016
VFR conditions expected at COS, PUB and ALS over the next 24 hours.
Winds will be diurnally driven. There is a very low chance that an
isold tsra could affect the COS and PUB taf sites this evening...but
the probability of this happening is very low.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOZLEY
AVIATION...HODANISH
Area Forecast Discussion
National Weather Service Pueblo CO
401 AM MDT WED JUL 13 2016
.SHORT TERM...(Today and tonight)
Issued at 344 AM MDT Wed Jul 13 2016
Currently...
MCS over nw KS continues to move E-SE. Outflow boundary has pushed
south and was approaching Kiowa NE Kiowa county at 3 am. Elsewhere
across the region...Clear skies dominated. Temps were mild...with
values ranging mainly in the 70s across most of the plains...and 40s
and 50s in the valleys.
Today...
Outflow boundary will likely make it south and westward and sfc flow
across the plains will likely become upslope by this afternoon.
Expect dry and hot conditions over the district today. It will also
likely remain dry...however guidance does hint at some light
convective precip possibly developing along the s mtns late in the
day. For now...my confidence is low in this happening and do not
have any precip fcst in the NDFD...although have 4-7% pops over the
S mtns and plains.
It will be very warm today as max temps will approach 100 over the
plains...especially along the US-50 corridor from Canon City
eastward to KS.
As for fire weather...no hilites have been issued...although near
critical fire weather conditions will occur. RH values will be quite
low across all of the region with many locations reaching min RH
values below 10%. These low values include the Hayden Pass fire
area. Winds on the other hand will be relatively low...with most
values in the 5 to 15 mph range. The only exception to this will be
along the Central mtn tops were a few gusts will approach 30 mph
during the afternoon. I do not expect any widespread significant
gusts over the Hayden Pass fire.
tonight....
A slightly better chance of precip will be possible although
confidence is low that it will actually happen. I have no QPF
mentioned (pops less than 10%)...but I cannot rule out an isold TSRA
late this evening across the plains and possibly adj southern mtns.
The best chance will be over the Palmer Dvd region late this evening
and during the early morning hours.
Oncoming shifts will have to monitor hi-res model trends regarding
increasing/decreasing pops over the region for tonight. /Hodanish
.LONG TERM...(Thursday through Tuesday)
Issued at 344 AM MDT Wed Jul 13 2016
Not much change to the forecast thinking through the extended
period with low ensemble spreads and consistency among the
operational solutions.
Thursday and Friday...flat high pressure will be centered over the
desert southwest with westerly zonal flow with embedded energy
moving across Colorado is forecast for late in the week. A cold
front will have backed west across the eastern plains by Thursday
morning advecting moisture along with easterly upslope flow over
the plains. This, combined with energy moving across the region,
will allow for shower and thunderstorm development by Thursday
afternoon. Expect initiation over the eastern mountains, spreading
east into the I-25 corridor during the late afternoon and evening
hours, before shifting east into western Kansas by Friday morning.
Given the moisture, locally heavy rainfall will be possible, and
burn scars will need to be monitored for flash flooding. In
addition, modest instability and shear may allow for one or two
stronger storms with gusty outflow winds and sub-severe hail.
Models continue to differ on Friday. The GFS and ECMWF have
similar solutions, with the next disturbance dropping southeast
across the far eastern plains Friday afternoon and evening. Both
solutions develop an MCS over northeast Colorado, and drop it
southeast into western Kansas, clipping our far eastern plains.
The NAM however, has this disturbance further west with enhanced
upslope flow across the plains leading to more widespread shower
and thunderstorm activity across the area. Given the model
differences, have low pops across the whole area for Friday
afternoon and evening. Locally heavy rainfall, gusty outflow winds
and small hail will all be possible, especially if a MCS does
develop over the far eastern plains.
Temperatures will be a bit cooler Thursday and Friday with
generally upper 80s expected across the lower elevations.
Saturday through Tuesday...the upper level pattern will begin to
amplify this weekend into early next week. An upper trough is
forecast to develop over the Pacific northwest, while the desert
southwest high pressure builds northward into the central plains.
This will bring increasing southwesterly flow aloft to southern
Colorado. Expect a drying and warming trend as the pattern
evolves. Limited moisture and weak steering flows will keep
diurnally driven showers and thunderstorms over the higher terrain
with little movement. Lightning over the mountains will need to be
monitored, as fuels are critical and wetting rains are not likely
to be widespread under the upper pattern.
Temperatures will warm rapidly this weekend given the enhanced
mixing with most areas across the plains reaching back into the
upper 90s to lower 100s. Mozley
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 344 AM MDT Wed Jul 13 2016
VFR conditions expected at COS, PUB and ALS over the next 24 hours.
Winds will be diurnally driven. There is a very low chance that an
isold tsra could affect the COS and PUB taf sites this evening...but
the probability of this happening is very low.
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOZLEY
AVIATION...HODANISH
[top]
Area Forecast Discussion
National Weather Service Denver/Boulder CO
359 AM MDT WED JUL 13 2016
.SHORT TERM...(Today and tonight)
Issued at 355 AM MDT Wed Jul 13 2016
Isolated strong storms finally exiting the far northeast corner of
the state in the pre-dawn hours. After that, expect mostly clear
skies through most of the day. Weak push from the north will bring
ever so slight cooling in the low levels on the plains so think
highs today may end up similar or just a degree warmer than those
observed yesterday, rather than a few degrees warmer as earlier
anticipated. Thunderstorm chances look practically nil during the
day, with only a slight chance near the Palmer Divide area toward
evening. That chance could expand on the eastern plains later this
evening into the overnight hours depending on potential for yet
another moisture surge/theta-e advection similar to what occurred
last night. Will have some low PoPs on the plains through the
entire night with weak Q-G lift slowly increasing.
.LONG TERM...(Thursday through Tuesday)
Issued at 355 AM MDT Wed Jul 13 2016
A 70-80 knot zonal flow up around 300mbs late Wed night gradually
shifts to more of a northwest component but with less strength as
heights rise over the Great Basin. The shift in flow transports
cooler air aloft down from Montana consequently resulting in
cooler sfc temperatures for the CWA on Thursday. The cooling
actually appears to begin late on Wednesday with passage of a weak
backdoor cold front. Model temperature guidance indicates a 3-5
deg f cool down from the day before...with most of the cooling
will be felt east of the mtns. Through the day bndry layer flow
on the plains transitions from northeasterly to southeasterly by
afternoon which advects higher theta-e air up into eastern
portions of the CWA...increasing the chance for convection...
particularly during the late afternoon and early evening hours
with the passage of the weak shortwave trough. NAM indicates sfc
based CAPES in the 2000-2500 j/kg range across Washington...Morgan...
Logan...ern Weld and Sedgwick counties along a wind shear axis.
GFS CAPES not as great and its best CAPES do not show up until
evening up along the Wyoming border with a stiff southeast wind.
Both models indicate the best likelihood for measurable precip
across eastern and southeastern sections of the CWA during the
evening hours when dewpt and PW values will be at their highest.
Could see storms linger well into the night across the eastern
fringe of the CWA. The risk of severe weather appears low although
an isolated t-storm or two could end up producing large hail and
heavy rainfall. The high country appears to remain dry on
Thursday...although the southern Front Range foothills and South
Park could see a few late day t-storms bubble up with stg
afternoon heating and a sely upslope flow. Otherwise...cooler
temperatures...higher RH and lighter winds should lessen the
wildfire danger in the high country.
By Friday...the upper ridge building out west moves a bit closer
which enhances the northwest flow aloft. However winds at low levels
differ in the models. GFS and ECMWF boundary layer winds east of the
mtns are predominately s-sely in direction throughout the day.
While the NAM starts out with sly winds in the morning then shift
to northerly winds in the afternoon creating a zone of convergence
on the plains which could act as a focus for thunderstorm
formation. Model max temperatures differ quite a bit on Friday.
The NAM temps are as much as 5-10 deg f lower than those offered
by the GFS and ECMWF. For now will use a blend of the models to
come up with Fri temps. If the NAM is correct the plains could see
a stormy day on Friday.
Saturday and beyond...upper ridge is progged to move east over the
state on Saturday and Sunday warming temperatures...lowering
humidity levels and reducing the chance of the t-storms. Should see
high temps return to the low/mid 90s at lower elevations. By
Monday...models show the upper ridge slipping east of the state
placing the CWA under a very warm and mostly dry southwest flow
aloft. May still see a few late day t-storms fire mainly over and
near the higher terrain as moisture begins to creep northward from
the Desert Southwest. By Tuesday...latest model runs show hints of
the American monsoon gaining strength over the desert Southwest.
Some of this moisture could spread as far north over our northern
mtns thereby increasing the chance of afternoon and evening
t-storms.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 355 AM MDT Wed Jul 13 2016
VFR conditions will persist through Thursday morning. Winds are
starting the day more northerly behind a weak surge early this
morning. Trend should be toward an anticyclonic wind pattern with
northeast to eventually southeast winds around 10 knots by
afternoon for the Denver metro area airports including KDEN.
Thunderstorm chance at or less than 10 percent, with slightly
better chances farther east including the northeast and southeast
Denver approach gates 00Z-12Z.
&&
.FIRE WEATHER...
Issued at 355 AM MDT Wed Jul 13 2016
Another very warm and dry day shaping up with the continued
westerly flow. Afternoon humidities are expected to drop into the
10 to 15 percent range over most of the forecast area...elevating
fire danger. Only locations that should experience critical wind
conditions with frequent gusts 25 mph or more in conjunction with
the low humidity would be North Park and Middle Park, the Mount
Zirkel Wilderness area including the Beaver Creek Fire, and the
northern Front Range Foothills mainly near the Wyoming border.
Have upgraded the Fire Weather Watch to a Red Flag Warning there.
Conditions should improve rather quickly early this evening as
winds subside.
&&
.BOU Watches/Warnings/Advisories...
Red Flag Warning from 10 AM this morning to 8 PM MDT this
evening for COZ211-213-215-217.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Baker
AVIATION...Barjenbruch
FIRE WEATHER...Barjenbruch
[top]
Area Forecast Discussion
National Weather Service Grand Junction CO
328 AM MDT WED JUL 13 2016
.SHORT TERM...(Today through Thursday)
Issued at 249 AM MDT Wed Jul 13 2016
Yes, another day of dry and hot conditions with some afternoon
clouds thrown in for good measure. Zonal flow remains in place as
we`re sandwiched between high pressure to our south and the more
active northern states. Guidance suggesting another breezy day
today especially along the Wyoming border where gusts of 25 to
30 mph look to be common. Further south, some higher gusts will
be felt but does not look as widespread so cancelled the fire
weather watch for zone 202 while upgrading the watch to a Red Flag
Warning for zone 200.
Thursday, more of the same as high temperatures will be a few
degrees warmer than today. Some afternoon breezes are expected but
not as high as we`ve seen lately.
.LONG TERM...(Thursday through Tuesday)
Issued at 330 PM MDT Tue Jul 12 2016
Conditions will remain relatively quiet, dry and warmer than
normal through early next week. Flow aloft will shift from the
west on Friday to the southwest this weekend and into early next
week. Isolated thunderstorms may arrive as early as Monday with
better chances Tuesday. Latest model data suggests less moisture
available on Tuesday than in earlier runs so coverage may be
reduced.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 249 AM MDT Wed Jul 13 2016
VFR conditions continue for the next 24 hours. Expect some breezy
afternoon winds.
&&
.FIRE WEATHER...
Issued at 330 PM MDT Tue Jul 12 2016
The fire weather watch for zone 202 has been cancelled with this
morning`s package. While some breezes will reach criteria, they
don`t look widespread enough to issue any warnings. However, for
zone 200, much of the area looks to have gusts between 25 to 30
mph while humidities will drop below 15 percent. The watch for
that area has been upgraded to a Red Flag Warning from noon
through 8PM. Day shift folk will need to keep an eye on 202 to see
if winds become more widespread than originally thought.
&&
.GJT Watches/Warnings/Advisories...
CO...Red Flag Warning from noon today to 8 PM MDT this evening for
COZ200.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...NL
AVIATION...TGR
FIRE WEATHER...TGR
Area Forecast Discussion
National Weather Service Pueblo CO
1134 PM MDT TUE JUL 12 2016
.UPDATE...
Issued at 930 PM MDT Tue Jul 12 2016
Removed POPS from the forecast tonight based on the HRRR, although
the HRRR does show the potential for storms to get near Kiowa
county so will have to keep an eye on that area.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 327 PM MDT Tue Jul 12 2016
...A Few Possible Storms on the Plains Tonight...
Current water vapor imagery and upper air analysis continues to
indicate moderate westerly flow aloft across the region with a minor
embedded short wave translating across the northern Great Basin and
Northern Rockies at this time. At the surface, induced lee low
between LHX and TAD has kept low level moisture and easterly to
southeast winds in place across most the eastern plains through the
early afternoon, with drier westerly winds across the higher terrain
starting to mix out west of the I-25 corridor at this time. The
drier westerly flow can also be seen with increased activity on the
Hayden Pass Wildfire...with its plume now evident on KPUX radar into
the afternoon.
For this evening, added pops across the Palmer Dvd and kept current
pops across the far southeast plains, as lastest model runs
indicating the potential for a few storms developing along moisture
gradient as induced surface low lifts out across the southeast
plains this evening and into southwestern Kansas overnight. SPC meso
analysis indicating 1000-2000 J/KG of CAPE along with some CIN
across the plains at this time. If storms can develop, there will be
enough shear to support isolated supercells, producing large hail
and strong winds, along with locally heavy rainfall.
For the rest of tonight and Wednesday, dry westerly flow aloft to
persist across the region with the embedded short wave translating
east across the Northern Rockies and into the Northern High Plains.
Should see breezy westerly flow persisting across the higher terrain
tonight, keeping temperatures up and dew pts low supporting poor RH
recovery, especially along and west of the I-25 corridor. This will
likely keep area wildfires more active overnight than previous
nights.
Flow aloft relax a tad through the day tomorrow, though will still
see breezy westerly winds across the higher terrain through the
afternoon. This supports some marginal critical fire weather
conditions, mainly across the central mountains, though this does
not look widespread enough to support a red flag warning at this
time. Temperatures to be at or slightly warmer than today,
especially across the eastern plains, where could see highs pushing
the century mark once again.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 327 PM MDT Tue Jul 12 2016
Hot Weather with some rain opportunities...
Wednesday night...northern shortwave will allow some cooler air to
infiltrate the eastern plains during the night, and moister east
flow pushing up against the eastern mountains late. Models not
indicating enough moisture or lift to produce any measurable rainfall
though.
Thursday and Friday...moist low level upslope flow across the
plains and I-25 corridor will persist Thursday into Friday, with
the possibility being greater for rainfall on the Hayden Pass
wildfire Friday afternoon and evening. A series of shortwaves
rippling through the westerly flow aloft will help in the
development of showers and storms across the CWA during this
period. There will be the potential for a couple marginally severe
storms each afternoon and evening from the eastern mountains into
the plains. Also, locally heavy rainfall will be possible and
eastern burn scars will need to be monitored for flash flooding.
Friday night into Saturday...models show a shortwave causing
showers and storms mainly north of our CWA, which could morph
into an MCS. Current trends are for this feature to be north of
our CWA, but, even so, it would send an outflow into our plains,
keeping the atmosphere on the moist side to the eastern mountains
over the weekend and into early next week.
Saturday through Monday...the upper level pattern will transition
to a trough along the west coast and high pressure across the
great plains. The resultant southwest flow aloft, along with
somewhat limited moisture and weak disturbances will yield
afternoon and evening isolated convection.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1133 PM MDT Tue Jul 12 2016
VFR conditions are expected across the TAF sites during the next
24H. A few patchy areas of stratus could develop across the far
eastern plains overnight, but will not impact KPUB and KCOS. Dry and
hot conditions are expected Wednesday with breezy winds gusting up
to 20 knots developing across the terminals during
afternoon. ~Lukinbeal
&&
.PUB Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...28
SHORT TERM...TM/MW
LONG TERM...TM/MW
AVIATION...MOORE/LUKINBEAL
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
642 AM CDT WED JUL 13 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 301 AM CDT WED JUL 13 2016
A complex of storms was located across northeast CO and northwest
KS early this morning. This complex of thunderstorms will begin to
forward propagate to the east and southeast along a deeper moisture
and instability axis that extends from south central KS and northwest
OK, northwest into northeast CO. If this complex of storms becomes
severe with damaging wind gusts as it moves southeast across west
central KS it may move into the southwest and southern counties of
the CWA after 12Z with the potential for severe wind gusts and heavy
rainfall generally south of I-70. The 00Z Nam model keeps the
complex southwest and south of the CWA during the morning hours. The
WRF solutions move the complex of storms across the southwest
counties after 12Z, then across the southern counties of the CWA
through the mid and late morning hours. The GFS moves the complex
due east across southern NE which clips the northern counties of the
CWA. The experimental HRRR moves the complex of storms east along
and just south of I-70 from 12Z through 17Z. The best chance for
strong to severe winds from this complex of thunderstorms will be
along and south of the nearly stationary outflow boundary which
extends along I-35 from south of KC, west-southwest to north of
Emporia, then due west. south of Salina, to north of Great Bend. If
this boundary drifts northward then there may be more of chance for
stronger winds up to I-70. Also, during the mid morning hours across
east central KS the boundary layer may mix deep enough with steep
lapse rates from 850mb to the surface for stronger winds aloft to be
entrained to the surface, if the complex of storms maintains it
intensity as it shifts east-southeast across the southern counties
of the CWA.
Wednesday afternoon through Tonight, the complex of storms will move
east-southeast across western MO. The outflow boundary may push
south of the CWA but should wash out across southeast KS. A weak
front will push southeast across the CWA and thunderstorms may
redevelop along and south of the weak surface front. The WRF and
experimental HRRR solutions show the surface outflow boundary
maintaining itself through the afternoon hours along and southeast
of I-35 where a line of storms or a complex of storms will develop
and push southeast of the CWA during the early to mid evening hours.
The NAM and GFS develop thunderstorms farther north across northeast
KS along the front during the afternoon hours, then forms a complex
of thunderstorms that tracks southward across east central KS during
the evening hours. At this time, I`m leaning more towards the meso
scale models. Any complex of thunderstorms may produce severe wind
gusts and heavy rainfall. Initial isolated to scattered
thunderstorm development may produce large hail. The NAM model
increases MLCAPE to over 5,000 J/KG this afternoon, which may be a
bit over done but if we see insolation this afternoon with dewpoints
in the mid 70s, we could see MLCAPES in the 3,000 to 4,000 J/KG
range. It will depends on where the storms develop to which areas
will have the best chances for severe thunderstorms during the
afternoon and evening hours.
Highs Today will depend on the track and timing of the mid and late
morning thunderstorm complex and if the cloud cover will scatter out
during the afternoon hours. If we see insolation this afternoon most
areas could see lower to mid 90s. If the thunderstorm complex moves
across the southern counties a few hours slower then east central KS
may keep cloud cover through the afternoon hours and highs may only
reach the mid and upper 80s. I think we will see break in the cloud
cover later this afternoon and have went with highs in the lower 90s
across the eastern and northern counties with mid 90s across the
southeast counties of the CWA.
.LONG TERM...(Thursday through Tuesday)
Issued at 301 AM CDT WED JUL 13 2016
Tomorrow the lingering frontal boundary should be located somewhere
in east central or southeast KS. The consensus is that it may be
located just south of the forecast area especially with storm
outflows pushing southward and reinforcing the boundary near the
OK/KS state line. The 12 km NAM is aggressive with developing an MCS
within the upslope flow over the high plains, and moving that MCS
along this boundary during the day Thursday. The WRF solutions
develop diurnal storms along the boundary in southeast KS. The other
larger scale models do not support this MC, and instead show
isolated to scattered storms developing late afternoon due to peak
heating and low level convergence similar to the WRF. There is a
chance this activity remains further south depending on the boundary
location. Given the uncertainty with morning showers and storms it
is difficult to determine if the environment will become favorable
for strong to severe storms Thursday afternoon. Instability if
realized should support a damaging wind threat and possibly hail. An
MCS during the afternoon would pose a wind threat as well.
A shortwave may also move across KS in the late evening into the
overnight and possibly support an MCS that could clip the far
southern forecast area. The track of this wave keeps gradually
shifting southward. Northwest flow aloft continues with subtle waves
moving over the region. Return flow will develop across the area
bringing moisture back northward. This pattern will favor possible
MCSs especially during the overnight with the strengthening of the
low level jet. This scenario may occur Friday night, but is too far
out to nail down exact timing and location. Mid level ridge begins
to build over KS, which pushes the storm track further north. One
more cold front may try to reach northern KS Sunday night and
Monday, but may only bring a small chances for storms to the area.
Beyond that looks rather dry and hot as the ridge centers overhead
into late week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 633 AM CDT WED JUL 13 2016
A complex of thunderstorms across portions of central KS will
continue moving east down the I-70 corridor throughout the
morning hours. Introduce VCTS at 13Z and TSRA at 14Z for the
Manhattan terminal. TSRA activity is expected to arrive at the
Topeka terminals near 15Z with VCTS possible after 14Z. Winds are
expected to shift to a northerly direction during the thunderstorm
activity with gusts 35+ knots. Thunderstorm activity should exit
MHK by 17Z and by 18Z at the Topeka terminals. Another round of
thunderstorm are possible this evening into the overnight. Will
continue to refine timing on those thunderstorms in future
outlooks.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Sanders
AVIATION...Baerg
Area Forecast Discussion
National Weather Service Denver/Boulder CO
350 PM MDT WED JUL 13 2016
.SHORT TERM...(This evening through Thursday)
Issued at 350 PM MDT Wed Jul 13 2016
Another afternoon with no shower activity through this time. Fair
weather cumulus have developed along the Front Range, but the
airmass over the mountains appears to warm and stable to support
the development of any thunderstotms. Dew point temperatures on
the plains have dropped ot the upper 20s and 30s with the
afternoon warming which would seem to preclude the development of
any thunderstorms on the plains. However, the NAM and HRRR are
once again forecasting showers to develop over the Palmer Divide
early in the evening which would spread to the eastern border by
midnight. A surge of low level moisture may move into the
northeast from Nebraska and western Kansas later this evening. If
this occurs, then nocturnal convection will be possible. Have held
on to isolated showers on the eastern plains later this evening.
Similar conditions are expected through tomorrow as the moderate
westerly flow aloft continues and weak high pressure builds in
from the north. Temperatures should be a few degrees cooler than
what we have seen the past few days.
.LONG TERM...(Thursday night through Wednesday)
Issued at 350 PM MDT Wed Jul 13 2016
There will be a moderate Northwest flow aloft over Northern
Colorado from late Thursday through Friday. The best chances for
storms will be again over the far Northeast plains of Colorado due
to higher levels of low level moisture. Earlier forecasts showed
some of this higher moisture levels further West towards the urban
corridor but now appears the focus for storms will remain farther
East again. Have raised Friday temperatures back into the upper
80s to near 90 for the urban corridor. Could be a few severe
storms over the plains given CAPE values in excess of 2000j/kg and
moderate Northwest flow aloft with resultant ample speed shear.
The flow aloft then turns back Southwesterly this weekend as a
trof deepens over the Pacific Northwest. Temperatures rise
even higher into the 90s over much of the lower elevations with
this warmer air from the Southwest. The upper ridge of high
pressure begins to build even further Northward into the Central
Plains by early next week. This will begin to steer some moisture
back Northward into Western Colorado and possibly the mountains
for a better chance for storms. The plains will likely be too
capped and dry for storms through the middle of next.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 350 PM MDT Wed Jul 13 2016
Dry and stable air remains over the i-25 and urban corridor
overnight which will keep any showers that develop over the
palmer divide and farther east on the plains. no aviation impacts
are expected at the Denver area airports other than wind shifts
from outflow boundaries generated by distant storms. Later this
evening should see the winds transition to southerly drainage
winds. Thursday morning will see northerly winds develop as weak
high pressure builds into the state from the north. Shower
activity on Thursday is expected to remain over the far eastern
plains until later in the afternoon when some showers will be
possible over the Palmer Divide.
&&
.FIRE WEATHER...
Issued at 350 PM MDT Wed Jul 13 2016
Marginal Red Flag conditions are occurring this afternoon, so the
Red Flag Warning will be continued through its expiration at 8 PM
this evening. Less wind is expected tomorrow afternoon and there
is a chance that dew points could be a couple degrees higher,
leading to slightly higher relative humidity levels. Should not
need any fire weather highlights tomorrow, though fire danger
conditions will remain elevated until we can get some shower
activity to develop over the mountains.
&&
.BOU Watches/Warnings/Advisories...
Red Flag Warning until 8 PM MDT this evening for COZ211-213-215-
217.
&&
$$
SHORT TERM...Dankers
LONG TERM...Entrekin
AVIATION...Dankers
FIRE WEATHER...Dankers