Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/11/18
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
402 PM PST Sat Nov 10 2018
.SYNOPSIS...Mild afternoons, chilly nights, and very dry conditions
will continue through the middle of the upcoming week as high
pressure remains in control. Sunshine will be plentiful in most
areas, however areas of thick smoke will linger across Mendocino
county into Sunday.
.DISCUSSION...An upper-level trough will pass by to our east while
surface high pressure builds across interior California and Nevada
heading into tonight. Meanwhile, an upper-level ridge will
build back across the West coast, largely remaining the dominant
feature through the upcoming week. This will mean continued dry
weather, with fire weather along with some areas of freezing low
temperatures remaining the main weather threats.
GOES-16 rapid-scan visible satellite still depicts thick smoke
across most of Mendocino county, with even some hazy skies
extending up into far southern Humboldt and Trinity counties this
afternoon. Webcams and surface observations back that up, with
visibility of only a mile or so across much of interior Mendocino.
Some of the HRRR model guidance has been arguing for improvement
today, but that clearly hasn`t happened. There are some signs of
at least the upper layers of smoke trying to drift off to the
south, and this trend should continue as northeast to east flow
increases aloft tonight. These winds will be felt across the upper
slopes and ridges for sure (see the fire weather discussion
below), however it is questionable how much will translate down
into the lower elevations and valley floors, especially with
colder air trapped under an inversion in those areas. Conveyed
the trend for lingering areas of smoke in the forecast for
southern Mendocino into Sunday, but later shifts may need to be
even more pessimistic.
Meanwhile, it will be another cold night into Sunday morning, with
lows similar to this morning. We will stop issuing frost
advisories and freeze warnings for some of the interior Mendocino
and Humboldt zones as those areas have seen widespread freezing
temperatures the last couple of nights, and the growing season is
effectively over. That said, those areas will see another night of
sub-freezing temperatures in many valley locations, and have
issued frost advisories for coastal Humboldt and Mendocino, as
well as freeze warnings just inland, for those areas where the
growing season has not yet officially ended. Temperatures should
gradually begin to moderate into early next week, but some frost
advisories will likely be needed for Monday morning yet again.
Otherwise, the forecast will remain pretty quiet with no
substantial threats of rain through next week. The tail-end of one
cold front will try to approach the corner of northwest
California, but will likely fail with perhaps just a few sprinkles
making it to Crescent City around Wednesday if we`re lucky.
Otherwise model guidance continues to keep any widespread rain
threat away until late next weekend. There are some signs that a
pattern change may finally take place toward Thanksgiving, but
don`t get too excited just yet. /AAD
.AVIATION...Del Norte, Trinity and Humboldt aviation sites continue
to be blessed by dry weather and an offshore flow regime. This has
resulted in VFR conditions for both KACV and KCEC. VFR conditions
will likely continue for the next 24 hours as easterly winds aloft
strengthen tonight. At the other extreme, Mendocino county is still
being impacted by smoke that originated from the CAMP FIRE in Butte
County. IFR visibility and MVFR layers of smoke (FU) will likely
continue tonight. Robust easterlies aloft above the inversion should
result in improvement late tonight through the day on Sunday as
mixing increases. Also, there is a potential for low level wind
shear late tonight into early Sunday morning as easterlies increase
above the inversion. This will be looked at more closely for the 00z
and 06z forecasts.
.MARINE...North winds from 20 to 30 kt are expected for the
remainder of today and through most of tonight across mainly the
outer waters. A few points inside 10NM may see locally strong gusts,
however winds should remain fairly light across the inner waters.
Steep wind waves have been increasing today and will continue on an
upward trend this evening, eventually peaking around 10 to 12 ft in
the outer waters. Wave model guidance continues to portray a tight
wave height gradient near the 10nm demarcation zone. For now will
maintain the advisories for the outer waters, though some short
period wave energy may creep into the outer fringes of the inner
waters. Conditions will start to settle down by early next week as a
mix bag of small swell groups and short period wind waves combine to
produce seas generally around 5 ft or less.
Early to mid next week, a steeply angled long period south swell is
set to fill in. This swell will most likely bypass the coastal
waters and remain offshore. A solid mid to long period west swell
will likely build around mid week. This westerly swell may bring a
moderate threat for sneaker waves.
.FIRE WEATHER...An exceptionally dry airmass, characterized by min
RH values locally approaching 0 percent followed by continued poor
overnight recoveries, will remain in place across the region
into the middle of the upcoming week. In addition, east winds will
increase this evening, with gusts over exposed high terrain up to
and locally over 30 mph. This will yield a critical fire weather
threat for elevations above 2000 feet from interior Del Norte
County southward across portions of Humboldt, Trinity, and
Mendocino Counties, prompting the Red Flag Warning. Winds should
improve Sunday night, and we may be able to end the warning early
based on that. However, humidity will remain very low into Monday.
An approaching trough and weakening front will likely not bring
any rain for mid-week, but will act to at least allow for some
higher humidity values by Tuesday and Wednesday.
CA...Frost Advisory from midnight tonight to 9 AM PST Sunday for
Freeze Warning from midnight tonight to 9 AM PST Sunday for
Red Flag Warning until 8 AM PST Monday for CAZ203-204-211-212-
NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until
3 AM PST Sunday for PZZ470-475.
Visit us at http://www.weather.gov/eureka
Follow us on Facebook and Twitter at:
For forecast zone information
see the forecast zone map online:
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1029 PM EST Sat Nov 10 2018
Issued at 1030 PM EST SAT NOV 10 2018
Did one last update to the temperatures before shift change.
Loaded in the latest observations to make sure the near current
forecast grid was on track with the latest conditions. Also
reworked the diurnal curve for the rest of the night to better
capture falling trend through 12Z. Generally kept low temperatures
the same, so these updates will not result in the need for another
forecast package. All updates were sent to NDFD/web.
UPDATE Issued at 910 PM EST SAT NOV 10 2018
Temperatures continue to drop off this evening, and are surpassing
the previously forecasted diurnal trends. After loading in the
latest observations, adjusted temperatures down a couple degrees
throughout the rest of the night to better capture the expected
temperature drops. Since we are currently sitting around the
current record low temperature for today, any further temperature
drops this evening will surpass the previous record. All updates
have been published and sent to NDFD/web. A new forecast package
was also sent out to reflect any changes to the overnight low.
UPDATE Issued at 707 PM EST SAT NOV 10 2018
With high pressure in control, and generally benign weather in
place, forecast remains in good shape this evening. Will continue
to monitor temperature trends as we head into the overnight since
strong subsidence and clear skies will lead to a quick drop off.
Loaded in the latest observations to make sure that the near term
grids were on track thus far. All updates have been published and
sent to NDFD/web. A new forecast package is not needed at this
.SHORT TERM...(This evening through Sunday night)
Issued at 340 PM EST SAT NOV 10 2018
20z sfc analysis shows high pressure firmly in control of the
weather throughout eastern Kentucky. This has cleared the sky and
is starting to settle the northerly winds. The full sunshine this
afternoon had a tough time warming the area with mid afternoon
readings in the mid 30s northwest to the low 40s in the far
southeast. Dewpoints, meanwhile are quite dry in the mid to upper
The models remain in good agreement aloft through the short term.
They all depict fast and slightly southwest flow over the area
through Sunday night before the next trough takes shape over the
Four Corners region. Only weak energy slips through the area ahead
of this trough through Monday morning. Given the small spread
among the models with the mid level pattern will favor a blended
solution leaning on the higher resolution HRRR and NAM12 for
Sensible weather will feature a very cold night under a clear sky
with light winds and low dewpoints. The radiational cooling will
likely result in a moderate to large ridge to valley temperature
split through the night. Clouds will be on the increase Sunday
with winds switching to the south and allowing temperatures to
rebound smartly into the mid and upper 40s north and low 50s
south. The clouds will continue to increase overnight into Monday
morning with pcpn on our southwest doorstep by 12z. The clouds
should limit the cool down Sunday night with only a small ridge to
valley difference anticipated - in fact readings may even rise in
the predawn hours.
Again used the CONSShort and ShortBlend as the starting point for
the grids. Did make the temps cooler tonight and also opened up a
decent ridge to valley split. As for PoPs - basically zeroed out
the PoPs through Sunday and then kept them sub 14 percent into
.LONG TERM...(Monday through Saturday)
Issued at 330 PM EST SAT NOV 10 2018
The extended will feature an active weather the first few days, and
quiet weather to finish things out. An area of low pressure will
bring rain and snow to eastern Kentucky from Monday through around
dawn on Wednesday. The biggest questions will be how quickly cold
air filters into the area Monday night, how far east snow is able to
form, and how much, if any, snow accumulation will occur across the
area. The most recent set of blended model data has warmed
temperatures up slightly during the passage of the low pressure
system mentioned earlier. This would cut down on any snow
accumulations, but due to model uncertainty and differences, this
should continue to be taken with a grain of salt. Temperatures will
continue to run well below normal, with highs maxing out 30s and 40s
Monday through Wednesday, and in the 40s and 50s to end the week.
Nightly lows will quite cold as well, with min readings in the upper
teens and lower 20s expected Tuesday night and Wednesday. The other
nights of the week will likely see lows in the low to mid 30s across
the area. Once the initial storm system exits the area, we can
expect a ridge of high pressure to settle over the region. This
should bring dry and slightly warmer weather to the area to end the
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 709 PM EST SAT NOV 10 2018
VFR conditions will dominate the aviation period as high pressure
remains in control of the region. Winds will be light and
variable overnight, resuming from the southeast to south by late
morning Sunday. Some high clouds may push into the region Sunday
evening towards the tail end of the TAF period.
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
832 PM CST Sat Nov 10 2018
832 PM CST
No changes to going forecast this evening.
Evening water vapor imagery shows a mid-level short wave tracking
eastward across the upper Mississippi Valley. West-southwest flow
in the low to mid levels was inducing isentropic ascent and
production of mid/high clouds along the southern periphery of this
system, across the LOT forecast area, though low levels remain
very dry in an early season arctic air mass. 00Z RAOB from DVN
shows this very dry low level air below about 800 mb. Radar is
picking up some weak returns across southern Wisconsin and the
northernmost tier of Illinois counties at this time, but likely no
precip will reach the surface due to sublimation below the
7000-8000 ft cloud bases. Will leave the chance of flurries alone
across those counties at this time, but I suspect most locations
will see no flakes.
Otherwise, temperatures will not fall off too much from current
values tonight, with modest south winds and extensive cloud cover.
Forecast appears to be in good shape overall, and no changes are
planned at this time.
124 PM CST
A chilly start to the weekend with early afternoon temperatures
similar to normals for Christmas as opposed to Veterans Day. Also
a winter-like look to satellite imagery with solid lake effect
clouds to our east, light snow cover across the western half of
the CWA, and the next Clipper system tracking into the Upper
The last of that list will see its parent closed mid-level low
drift well north of the area tonight, however its southern
influence will bring quickly thickening clouds early this evening.
Weak to modest isentropic ascent within this system`s warm
advection wing is depicted by both the RAP and NAM, as also is
very dry sub cloud air (below ~6000 ft). Upstream observations
have supported this, such as the 12Z OAX sounding and current
surface observations across northern Iowa that are indicating no
light snow below virga thus far. Considering this, some high-
resolution guidance that is bringing light snow into far northern
Illinois tonight likely is a bit overdone. Have a small chance
for flurries/brief light snow across the far north this evening
and early overnight, and if it materializes south of the Wisconsin
border should be of no to very little impact.
With clouds moving in as the sun sets and southerly winds inching
their way up overnight, there should be little temperature drop,
with steady temperatures in many places in the mid 20s.
224 PM CST
Sunday through Saturday...
A relatively quiet period is expected for the long term forecast
period, with below to well-below normal temperatures and only a
couple opportunities for some light pcpn.
High pressure centered over the Ohio Valley this afternoon will
slowly settle across the Mid-Atlantic region Sunday and then move
off-shore early next week. Surface ridging will extend across the
sern CONUS and northern Gulf Coast, limiting any moisture advection
into the area and only the minimal in-situ moisture will be
available until at least Tuesday. A weak shear-out shortwave
tracking across cntrl IL/IN could bring some light snow to the far
southern portions of the CWA late Sunday night into Monday morning,
but with limited moisture and only weak upper forcing, little or no
accumulation is likely. Pcpn chances will shift to more of a lake-
effect pattern Monday night and Tuesday as a sfc low developing over
the Lower Mississippi Valley Monday night tracks northeast to New
England by Tuesday afternoon as a sfc ridge builds across the
plains. Nwly flow will bring another shot of colder air to the
Upper Midwest and Great Lakes region. Some moderation to
temperatures is expected for sunday and Monday, but the reinforcing
shot of cold air on Tuesday will drive temperatures down from highs
in the upper 30s on Sunday to the mid to upper 20s on Tuesday.
latest guidance suggests that the wind fetch over lake Michigan
should be closer to west-northwesterly than true northwesterly,
minimizing the lake effect potential to perhaps only the far
northeast corner of Porter County and more likely for north-central
Indiana and southwestern Michigan. As the sfc ridge progresses east
through the middle of next week, a return to dry weather is expected
with temperatures moderating back into the middle 40s for Thursday
and Friday. While this warming trend would reflect a 20 degree
temperature swing from highs in the middle 20s on Tuesday to the
middle 40s by Thursday. So, the forecast Max Temp of 44 F for
Chicago and Rockford on Thursday November 15 still 4 degrees below
the normal High Temp of 48 F for Rockford and 5 degrees below the
normal High Temp of 49 F for Chicago. The coldest morning of the
period should be Wednesday morning with lows in the lower teens west
of the Fox Valley and north of I-80 and the middle to upper teens
for the remainder of the CWA. Even the typically warmer Chicago
area urban heat island could see lows in the teens. The forecast
lows Wednesday morning are close to 20 degrees below normal.
For the 00Z TAFs...
Quiet aviation weather period through Sunday, with no major
Surface high pressure continues to drift southeast across the Ohio
Valley this evening. Winds have backed to the south across the
terminals, and are expected to remain south-southwest through the
day Sunday. The gradient will tighten a bit this evening allowing
speeds just under 10 kts, and with some mixing Sunday should
produce gusts in the 15-20 kt range at times. Aloft, VFR clouds
were thickening across the region in association with an upper
level disturbance tracking toward the upper Midwest. Mid deck will
develop and lower overnight, but should remain above 5000-6000 ft
agl for the most part. A few flurries aren`t completely out of the
question, especially from KRFD northward, though the low level
arctic air mass is quite dry and no significant precip threat is
Low pressure passes across the northern Great Lakes Sunday, and
will trail a cold front into the forecast area Sunday evening. Not
much more than a wind-shift to the northwest is expected, though
guidance does suggest some potential for patchy MVFR ceilings
Sunday night. Precipitation developing along the front Sunday
night is expected to remain south of the terminals.
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
Area Forecast Discussion
National Weather Service Sacramento CA
423 PM PST Sat Nov 10 2018
Dry with warmer than normal temperatures through next week. Critical
fire weather conditions return tonight through Monday morning.
Widespread smoke from the Camp Fire will continue to impact much
of the area.
Latest satellite imagery reveals widespread smoke and haze
enveloping interior NorCal due to the Camp Fire. Afternoon
temperatures are currently in the upper 50s to mid 60s across the
Valley, except for the northern Sacramento Valley where wildfire
smoke is not impacting the area. Poor visibilities are occurring
across portions of the Central Valley and the Delta, with some
locations reporting visibilities less than a mile. As such, a
Dense Smoke Advisory is in effect through 4 AM Sunday due to poor
The forecast area remains on the east side of Pacific ridging,
with a dry airmass over the area. An upper trough will continue
to drop into the Great Basin tonight into tomorrow, with another
round of gusty north to east winds developing overnight. The
enhanced surface gradient will result in gusty winds tonight,
mainly across portions of the western Sacramento Valley and the
western slopes of the Sierra Nevada. The strongest winds will
last through about 11 AM, with winds decreasing during the day as
pressure gradient relaxes. Winds will pick up again late Sunday
into early Monday, mainly over the northeastern foothills/mountains.
The combination of gusty winds and low humidity will lead to
critical fire weather conditions tonight into Monday morning.
Therefore, a Red Flag Warning remains in effect for most of
interior NorCal through Monday morning. Lighter winds are expected
Monday afternoon as surface pressure gradients relax.
HRRR smoke model keeps a similar type of smoke plume again on
Sunday. Periods of dense smoke will be possible across the Valley
for the next few days, although it`ll be difficult to determine
breaks in smoke. Therefore, smoke will continue to be an issue
in terms of air quality, visibility, and reduced temperatures.
No precipitation is expected across interior NorCal as high
pressure remains in control of the region. Daytime highs are
expected to be 5 to 10 above seasonal normals through the forecast
period. Forecast highs will be in the mid 60s to mid 70s across
the Valley. Morning lows are anticipated to be in the 30s to mid
40s across the Valley, with in the 10s to low 20s across mountain
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
Dry weather with mild days and cool nights expected to continue
during the second half of next week as a strong ridge remains over
the West downstream of a deepening trough over the eastern
Pacific. No strong wind events are expected. The mountain areas
and far northern portion of the forecast area may see a few
showers by next Saturday as the initial batch of short-wave energy
moves ashore, but confidence in details remains low.
Smoke from Butte County wildfire will continue to drift mainly
southward the next 24 hours resulting in areas of MVFR with local
IFR conditions. Elevated smoke layer expected to remain around
050-070 from around the Sacramento area southward. Look for
increasingly gusty northerly winds of 15-25 kts across the
Sacramento Valley TAF sites after 06Z Sunday. &&
Red Flag Warning from 10 PM this evening to 7 AM PST Monday for
Burney Basin and Northeast Plateau in Shasta County Including
Northwest Lassen NF north of Lassen NP-Carquinez Strait and
Delta-Central Sacramento Valley in Glenn, Colusa, Yuba, Northern
Sutter, and Butte County Below 1000 Ft-Eastern Mendocino NF-
Eastern Portion of Shasta/Trinity NF-Lake County Portion of Lake-
Napa-Sonoma Unit-Northern Motherlode From 1000 to 3000 Ft.
Includes portions of Nevada-Yuba-Placer-Amador and ElDorado
Units-Northern Sacramento Valley to Southern Tehama County Line
Below 1000 Ft-Northern Sierra Foothills from 1000 to 3000 Ft.
Includes portions of Shasta-Trinity and Butte Units-Northern
Sierra Including Lassen NP and Plumas and Lassen NF/S West of
the Sierra Crest (West of Evans Peak-Grizzly Peak-Beckworth
Peak)-Northern Sierra Including the Tahoe and ElDorado NF/S West
of the Sierra Crest-Southeast Edge Shasta-Trinity NF and Western
Portions of Tehama-Glenn Unit-Southern Motherlode From 1000 to
3000 Ft. Includes portions of Calaveras-Tuolumne Unit-Southern
Sacramento Valley in Yolo-Sacramento Far Western Placer,
southern Sutter and Solano County Below 1000 Ft-Stanislaus NF
West of the Sierra Crest.
Wind Advisory from 10 PM this evening to noon PST Sunday for
Motherlode-Northeast Foothills/Sacramento Valley-West Slope
Northern Sierra Nevada-Western Plumas County/Lassen Park.
Dense Smoke Advisory until 4 AM PST Sunday for Carquinez Strait
and Delta-Central Sacramento Valley-Motherlode-Northeast
Foothills/Sacramento Valley-Northern San Joaquin Valley-Southern
Area Forecast Discussion
National Weather Service Las Vegas NV
445 PM PST Sat Nov 10 2018
.SYNOPSIS...Sunny skies and cooler temperatures expected through
the weekend. Windy conditions are expected on Sunday as another
dry cold front moves through. This will be followed by benign week
with sunny skies with slightly below average temperatures.
.UPDATE...Visible satellite imagery along with regional webcams
show increasing smoke moving into the western edges of the forecast
area, mainly across Inyo and San Bernardino counties. Some lofted
higher altitude smoke has also been reported in the Vegas Valley
this evening. I went ahead and updated the weather grids to include
smoke wording tonight, mainly for the Western Mojave Desert near
Barstow, and Inyo county within the Owens Valley, as HRRR smoke
forecasts bring increasing near surface smoke concentrations into
these areas overnight.
Luckily, swift moving cold front will move through by day break
which will help to clear the air in time for Sunday across the
entire region. The rest of the forecast is in good shape and no
other updates are planned.
.SHORT TERM...through Tonight.
Cool conditions will continue through the afternoon with temperature
readings around the region just below normal values. A shortwave
trough axis, currently positioned over the northern Great Basin,
will continue to move southeastward overnight. As it does, it will
usher in cold front that will bring gusty north winds to the region.
These northerly winds are expected to stay below Wind Advisory
criteria this evening. With clear skies tonight, overnight lows will
range from mid 30s to low 50s in valley locales and from single
digits to low 20s at higher elevations across the southern Great
Basin and Mojave Desert.
.LONG TERM...Sunday through Saturday. Main concern is still the next
wind event down the Colorado River valley Sunday. Models have
changed very little from yesterday, so left the Lake Wind Advisory
in place and upgraded the Fire Weather Watch to a Red Flag Warning.
Models also still agree on high amplitude Pacific ridging nosing in
Monday, reducing the winds. This high will remain in control through
much of the upcoming week, although it will weaken a bit as the next
trough rides into the Pacific Northwest Wednesday. The high pressure
will allow temperatures to rise about ten degrees from Monday to
Friday. There are still some disagreements on how the pattern might
shift by next weekend, but there is strong consensus on dry weather
continuing, with temperatures near or slightly above normal.
.AVIATION...For McCarran...Light winds will continue through the
afternoon remaining below 7 knots. Winds will begin to shift to the
northwest tonight as a cold front approaches the valley. North winds
will initially push in around 8-12 knots around 10z-12z. Speeds are
expected to increase along with gusts between 16z-18z. North winds
will persist through Sunday gradually decreasing Sunday evening.
VFR conditions through the period.
For the rest of southern Nevada, northwest Arizona and southeast
California...Generally light winds will continue through the
afternoon. A cold front will begin to push into the region tonight
and bring gusty north winds along with it. North gusts will be
15-30 knots at most locations, except along the Colorado River
where gusts may reach 40 knots. VFR conditions through the period.
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter