Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/12/18
Area Forecast Discussion
National Weather Service Gaylord MI
957 PM EST Sun Nov 11 2018
.UPDATE...
Issued at 957 PM EST Sun Nov 11 2018
Lake effect into the tip of the mitt had consistently waned since
the previous update. That is, until the last 45 minutes or so,
when another (final?) shot of mid-level moisture has contributed
to an uptick into Emmet Co. Suspect this will be relatively brief,
as mid-level moisture will decrease as 500mb heights tick upwards
ever-so-slightly overnight. Nam Bufr soundings at PLN show drying
in the 5-10k ft layer overnight, and a corresponding lowering of
inversion heights from 7k to 5k ft.
So expect the current uptick to be relatively brief, but it is
enough to warrant maintaining the current headlines over far
northern lower MI. Meanwhile, sub-850mb winds have veered enough
such that bands are just scraping by St Ignace and Drummond Isl.
Advisories for Chip/Mack Cos were set to expire at 10pm, and have
let them do so. Have also lowered Leelanau-Antrim Cos; there is
little going on there now, and though activity will migrate
southward with time overnight into the morning, we should be in a
weakening stage by then.
UPDATE Issued at 632 PM EST Sun Nov 11 2018
Continued vigorous lake enhanced bands poking into far northern
lower MI have required an upgrade to a warning for Emmet Co. The
central portion of Emmet, between Levering and Petoskey, will see
total accums of 5-10 inches. Recent HRRR runs show nearly 0.50"
of liquid QPF in this area. That is probably a little too high,
which is good, as that would equate to over a foot of snow.
Will be cautiously watching neighboring counties (especially
Cheboygan) for any potential need for an upgrade.
&&
.NEAR TERM...(Through Tonight)
Issued at 300 PM EST Sun Nov 11 2018
...Lake Snow Showers Through Tonight...
High Impact Weather Potential: Accumulating lake snows for parts
of NW lower Michigan.
Pattern Synopsis/Forecast: Afternoon analysis reveals low
amplitude short-wave trough advancing across northern Michigan,
attending surface low is across the U.P./Lake Superior. Main QG-
forcing for ascent ahead of the wave is moving out of the CWA
evidenced by diminishing trend to the larger scale snowfall across
the region. But SW flow enhancement continues off Lake Michigan
into NW lower Michigan of course with the heaviest snows impacting
the Lake Michigan shoreline from Grand Traverse Bay up through
Charlevoix/Emmet and parts of Cheboygan county and eastern upper
Michigan.
Primary Forecast Concerns: Ongoing lake enhancement and
accumulations.
QG-forcing for ascent and remaining widespread snowfall ends this
evening. However, low level flow veering more westerly in time
and favorable lake effect parameters will continue to target areas
from Leelanau county up through the tip of the mitt for a good
part of the night. Plan to extend/expand advisories for Emmet/
Charlevoix Cheboygan counties through tonight and I may add
Leelanau and Antrim counties back into the mix for good measure
(with lake banding skirting Leelanau and heavier elements
impacting Antrim county).
Further north, it`s been difficult to tell exactly what`s
happening today along the Lake Michigan and Huron shoreline. But
have to believe that heavier convective elements are getting into
the southern parts of Chip/Mack counties. Will probably just leave
the advisories up there alone for now. They expire at 03Z which
corresponds well with winds veering more westerly tonight.
&&
.SHORT TERM...(Monday through Wednesday)
Issued at 300 PM EST Sun Nov 11 2018
High Impact Weather Potential: Accumulating lake effect snow
expected at times, primarily across WNW/NW flow snowbelts.
Pattern Synopsis: Winter-like pattern continues through midweek
across northern Michigan led off by a weak cold front crossing the
forecast area during the day Monday, all while a storm system a
storm system emerges across the southeastern tier of the CONUS and
rides toward the East Coast. A well-defined shortwave will carve
through the Great Lakes region on Tuesday, bringing a reinforcing
shot of cold air before heights aloft slowly begin to rise through
the day Wednesday...at least briefly.
Primary Forecast Concerns/Challenges: Lake effect snow potential
through the forecast period.
Overall large scale pattern will remain supportive of continued lake
effect snow chances downwind of Lake Michigan and Lake Superior
Monday through at least Tuesday night. Aforementioned cold front
crossing the region during the day Monday along with renewed
troughing overhead as shortwave troughing digs into the region
Monday night-Tuesday will combine to deliver continued cold air
aloft...evident by H8 temps falling from roughly -10 C Monday
morning to -16 C. Plenty of lake induced instability will result as
delta Ts range from 15-20 C; however, as was alluded to by the prior
forecaster, subsidence inversion heights through the period
generally varying from 4-6 kft and moisture limited to sub 800 mb
should limit the overall coverage and intensity of snow showers.
Steering flow varying from WNW to NW should focus the most
persistent snows across the typical areas of northern
Chippewa/northwest Mackinac counties and along and west of I-75
across parts of northwest lower. Tuesday will likely be the day to
feature more robust snow shower activity as synoptic support
increases from the aforementioned shortwave sliding across the
region overhead. In terms of snowfall amounts, generally an inch or
less during the day Monday, and 1-2" in any 12-hour block of time
Monday night through Tuesday night at any given location with the
WNW/NW flow snowbelts.
Lake effect chances will gradually diminish Tuesday night into
Wednesday as heights begin to rise and low-mid level warm air
advection takes over.
Below normal temperatures continue through the period with the
coolest day expected on Tuesday as high temperatures top out in the
mid-upper 20s for most areas...perhaps tagging 30 degrees nearest
the Great Lakes shorelines.
.LONG TERM...(Wednesday night through Sunday)
Issued at 300 PM EST Sun Nov 11 2018
High Impact Weather Potential: Additional accumulating snow possible
Friday through the remainder of next weekend.
Rather tranquil conditions expected Wednesday night through Thursday
night across northern Michigan; however, a potent clipper system and
attendant cold front is expected to sweep across the region on
Friday. This is expected to lead to more accumulating snow chances
across parts of northern Michigan through the remainder of next
weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 632 PM EST Sun Nov 11 2018
IFR at PLN tonight. Otherwise MVFR to VFR.
Lake enhanced snow continues in northern MI. This is light is most
places, but far northern lower MI is seeing more vigorous snow
showers. PLN had miserable conditions this afternoon; those have
improved somewhat as the better banding has drifted south. Still
expect IFR conditions in snow tonight at PLN, and would not
preclude occasional LIFR. Elsewhere, VFR to MVFR conditions will
prevail in light snow and with a lake-induced stratocu deck.
Light winds tonight, a w to nw breeze Monday.
&&
.MARINE...
Issued at 300 PM EST Sun Nov 11 2018
Southwest winds have been a little gusty today but largely short
of small craft advisory criteria. Have already trimmed out the
Lake Michigan nearshore zones and the Lake Huron zones will end at
6 pm this evening. Winds gradually veer into the NW tonight
through Monday. But I do not anticipate any marine headlines for
the next few days.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY until 5 AM EST Monday for MIZ017-019.
WINTER STORM WARNING until 5 AM EST Monday for MIZ016.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
NEAR TERM...BA
SHORT TERM...MG
LONG TERM...MG
AVIATION...JZ
MARINE...BA
Area Forecast Discussion
National Weather Service Cheyenne WY
422 PM MST Sun Nov 11 2018
.SHORT TERM...(This evening through Monday night)
Issued at 235 PM MST Sun Nov 11 2018
Water vapor loop depicted a trough axis from south central Canada
southwestward through the central Rockies. A shortwave was moving
from south central MT into northern WY. Most of the snow shower
activity over southeast WY was decreasing in coverage and intensity,
with redevelopment from northern WY into western SD. The Winter
Weather Advisory was cancelled shortly before 2 PM as WYDOT
webcams showed improving road conditions along the I-80 corridor
from Cheyenne to Arlington/Elk Mountain. Temperatures ranged from
the lower 20s to mid 30s and winds were northerly 5-15 mph.
Models/ensembles are in good agreement progging the shortwave
to the north to quickly dive south across WY into CO tonight and
early Monday. Only minor snow accumulations, an inch or less, are
forecast with drier air aloft as the shortwave passes overnight.
The light snow will end by Monday morning, with clearing skies and
cold temperatures Monday afternoon as 700mb temperatures hover
around -15C. After lows tonight in the single digits and lower
teens, lows Monday night will moderate into the teens.
.LONG TERM...(Tuesday through Sunday)
Issued at 235 PM MST Sun Nov 11 2018
A trend toward warmer and drier conditions can be expected through
the extended forecast period, as large scale upper ridging becomes
established over much of the western CONUS. H7 temperatures return
to around 0 deg C by Wednesday, suggesting the potential for highs
in the 50s and lower 60s across the Plains. The chances for rain &
snow will be low through the period w/ the lack of any substantial
weather system. We may be on the very fringe of a more active flow
pattern by Thursday and Friday as a clipper system tracks over the
Northern Plains, but moisture appears very limited at this time.
Cooler than average temperatures Friday and Saturday will moderate
back to above normal Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 419 PM MST Sun Nov 11 2018
Have a secondary cold front moving into the area from the north
this evening. There are indications that our southeast Wyoming
airports could see lower ceilings. Concentrated on KCYS and KLAR
for these lowering conditions as guidance shows this is where the
snow is going to develop. HRRR guidance hinting at IFR/LIFR
conditions at these two airfields as well. As front drops south,
MVFR conditions expected at out Panhandle airports through
sunrise.
&&
.FIRE WEATHER...
Issued at 230 PM MST Sun Nov 11 2018
Periods of light snow will persist through tonight with minor
accumulations. Cold temperatures will continue through Monday
night, followed by dry and milder conditions Tuesday and Wednesday.
Fire weather concerns will be minimal due to non- critical winds
and humidities.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...MAJ
LONG TERM...MAJ/CLH
AVIATION...GCC
FIRE WEATHER...MAJ
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1002 PM CST Sun Nov 11 2018
.UPDATE...
Light to moderate showers will continue to affect areas along
and east of Highway 281, especially the Hill Country and the far
southeast counties of our area tonight. Latest HRRR model run
suggests for the shower activity to diminish significantly overnight
into Monday morning. Not buying into this solution just yet with a
cold front approaching from the north and a coastal low nearing the
mid to upper Texas coast. Therefore, we will keep chances for rain
ranging from 50 to 80 percent for areas along and east of Highway 281
through Monday morning.
The cold front is expected to move across South Central Texas
Monday morning with showers mainly affecting the Hill Country
and southeastern counties. In the wake of the cold front,
expect breezy to windy conditions and gusts up to 40 mph
in the afternoon into the evening hours. A wind advisory is
likely to be issued overnight or Monday morning if models continue to
suggest elevated wind values. It is also likely that max temps occur
before noon Monday as temps begin to drop in the afternoon and
evening. By 8 PM, some areas across the Hill Country are expected to
get freezing temps. The freezing temps will continue to spread south
into the escarpment area through Tuesday morning. A Freeze Warning is
in effect from 8 PM to 9 AM Tuesday for areas west of Interstate 35
and north of Highway 90. Another cold night is expect Tuesday night
into Wednesday morning with a widespread freeze for all of South
Central Texas.
Dry weather conditions expected Tuesday into Friday with a warm up
middle to the latter part of the week with highs in the mid 60s Friday.
&&
.PREV DISCUSSION... /ISSUED 607 PM CST Sun Nov 11 2018/
AVIATION.../00Z TAFS/
Widespread light rain and drizzle will continue to move over most of
South Central TX with only the DRT area not seeing radar echoes.
There could be a brief shot of drizzle or a shower at DRT, but will
wait and adjust as needed given not much attention given to that area
by the mesoscale models. Will keep the eastern TAFs simple as
prevailing ifr, but there could be brief dips to lifr from both
lowered cigs and also from brief heavy downpours that might lower
vsby to below 1 mile. A short period of lifr is included as a strong
cold front approaches the I-35 corridor, and a boost in rainfall
rates near the front could provide the more likely limitation. Once
the front arrives, between 13Z and 17Z, strong winds should mix out
the low level cigs to mvfr levels and eventually vfr several hours
later.
PREV DISCUSSION... /ISSUED 242 PM CST Sun Nov 11 2018/
SHORT TERM (Tonight through Monday Night)...
Water vapor imagery shows a deepening trough, currently digging into
the lower desert southwest. Coastal low off the middle Texas coast
coupled with an increasing low-level jet is generating showers in our
eastern counties. These showers could strengthen to thunderstorms as
instability increases and becomes more widespread. Rain chances
continue into Monday as the strong cold front associated with the
trough pushes down into south central Texas with strong wind and very
cold temperatures behind it. No frozen precipitation is expected
behind this front as the moisture is not deep enough. Most of the
Hill Country will see below freezing temperatures Monday night into
Tuesday morning as the rest of the areas will be either at or just
above.
LONG TERM (Tuesday through Sunday)...
As the trough axis moves through skies will clear amplifying
radiational cooling. Tuesday night into Wednesday morning will be
the coldest night where freezing temperatures reach all the way down
to the coastal plains. Please remember to bring your pets indoors.
This cold dry airmass will stay in place through the week with only
slight modification later in the week as a slow warming trend begins.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 48 52 33 47 29 / 70 60 10 10 10
Austin Bergstrom Intl Airport 48 52 34 47 27 / 70 50 10 10 10
New Braunfels Muni Airport 50 54 33 49 27 / 60 50 10 10 10
Burnet Muni Airport 46 48 29 46 26 / 70 50 10 10 -
Del Rio Intl Airport 53 57 35 52 29 / 20 10 10 10 -
Georgetown Muni Airport 47 49 31 46 27 / 70 60 10 10 -
Hondo Muni Airport 52 62 33 52 26 / 40 30 10 10 -
San Marcos Muni Airport 49 54 34 47 27 / 60 50 10 10 10
La Grange - Fayette Regional 49 53 34 47 28 / 70 60 20 10 -
San Antonio Intl Airport 51 57 33 50 27 / 50 40 10 10 10
Stinson Muni Airport 52 59 35 51 28 / 50 40 10 10 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from 8 PM Monday to 9 AM CST Tuesday for Bandera-
Bexar-Blanco-Burnet-Comal-Edwards-Gillespie-Hays-Kendall-Kerr-
Kinney-Llano-Medina-Real-Travis-Uvalde-Val Verde-Williamson.
&&
$$
Aviation...Oaks
Short-Term/Long-Term...17
Area Forecast Discussion
National Weather Service Lincoln IL
843 PM CST Sun Nov 11 2018
.UPDATE...
Issued at 835 PM CST Sun Nov 11 2018
A weak cold front, analyzed across far west central Illinois this
evening is expected to push through our area tonight. Not much in
the way of weather associated with the boundary at the present
time. Short term models continue to indicate some patchy light
precipitation may develop along and immediately behind the front
later tonight/early Monday morning but amounts look to be quite
light, if it occurs at all. HRRR soundings slow to saturate the
lower levels overnight so the current low POPs over the central
sections of our forecast area look good for late tonight.
As the boundary continues to slide into southeast Illinois on
Monday, an upper level trof will rotate east across the Great
Lakes. In addition, parts of our area will be in the favorable
right rear quadrant of a speed max at 300 mb with more significant
lift noted on deterministic models with the speed max, especially
just to our south, so POPs increase to likely or higher across
south central through southeast IL during the day. Snowfall
amounts look to be on the light side, generally an inch or less,
roughly along and south of a Jacksonville to Champaign line.
Current forecast looks reasonable at this time with only a few
minor tweaks to the grids based on early evening trends. As a
result, no ZFP update is needed at this time.
&&
.SHORT TERM...(This evening through Monday night)
ISSUED AT 330 PM CST Sun Nov 11 2018
1029 mb high pressure near the mid Atlantic coast was ridging
westward into the mid MS river valley at mid afternoon. This was
keeping a dry and cool air mass over central and southeast IL
today with 3 pm temps 40-45F. A weak 1019 mb surface low pressure
was just nw of Lake Superior with its cold front extending
through western WI into eastern IA and nw MO. Mid level clouds
were south of I-72 while some passing cirrus clouds along and
north of I-72. Radar mosaic shows some light radar returns along
and south of I-70 into central MO but this appears to be virga
coming out of mid level clouds with base of 9-10k ft. Plus air
mass quite dry with temp/dewpoint spreads of 20-27F.
Models continue to keep CWA dry through this evening as mid level
clouds increase over central IL. Some 850-925 mb frontogenetic
forcing to develop a band of light snow into central IL during
overnight into Mon morning, mainly between the IL river and north
of I-70 as surface cold front moves se across CWA. Little or no
snow accumulation expected with this initial band of light snow.
Lows overnight mostly in the upper 20s, but range from mid 20s nw
of the IL river to around 30F in southeast IL. Highs Mon range
from lower 30s along and nw of I-55, to the upper 30s to near 40F
in southeast IL.
1012 mb surface low pressure off the south Texas gulf coast to
track ne to the LA delta by 6 pm Mon, and move or reform off the
mid Atlantic coast by sunrise Tue, then deepen up the New England
coast on Tue. Better chance of light snow to occur Mon afternoon
and Mon evening se of the IL river from this southeast US storm
system. A mixture of light rain with light snow south of I-72 by
Mon afternoon and mainly light rain se of I-70 Mon afternoon. But
colder air arriving late Mon into Mon evening to change mix pcpn
to all light snow. Though southeast IL could see a chance of light
freezing rain/drizzle too during Monday night. Snow accumulations
up to 1 inch possible along and south of I-72 and from I-70 north
Mon afternoon and Mon evening with light ice around 0.05 inch or
less in southeast IL Mon night. Colder Mon night with lows ranging
from mid teen nw of the IL river to mid 20s near Lawrenceville.
Wind chills will drop into the single digits during overnight over
central IL.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 330 PM CST Sun Nov 11 2018
Dry and unseasonably cold wx expected Tue through Wed across CWA
as Canadian high pressure settles into the MS river valley on Tue
night into Wed morning. Despite return of mostly sunny skies Tue,
it will be quite cold with brisk nw winds. Highs only in the
upper 20s in central IL and lower 30s in southeast IL on Tue. Tue
night looks to be the coldest night across the CWA with lows in
the teens. Record lows for Tue/Nov 13 and Wed/Nov 14 along with
record cold highs for Tue/Nov 13 are listed in the climate section
below. A fair amount of sunshine Wed with light winds but still
pretty cold with highs in the mid to upper 30s. Lows Wed night in
the low to mid 20s, similar to readings we had this past night.
The 12Z models are now showing a strong cutoff 500 mb low moving
into ne AR by sunrise Thu, and lifting ne over the Ohio river
valley on Thu night. GFS model appears too fast with spreading qpf
into se IL overnight Wed night and prefer the slower Ecmwf model.
The GEM model is even slower, but followed middle of the road with
Ecmwf model. Best chances of light pcpn will be east of IL river
on Thu, with mainly light snow south of I-72 Thu morning and
chance of rain showers east of IL river Thu afternoon. Pcpn turns
to light snow during Thu evening and diminishes overnight Thu
night. Could be some light snow accumulations around 1 inch Thu
night in eastern IL. Highs Thu in the upper 30s and lower 40s.
Lows in the upper 20s Thu night. Highs Fri of 40-45F. A broad
upper level trof lingering over Great Lakes and into the Ohio
river valley to keep us on the cooler side next weekend with highs
in the mid 30s to lower 40s. Chances of light pcpn look low with a
few weak short waves passing through the trof.
Extended forecast models show a milder trend during Thanksgiving
week as upper level heights rise over the Midwest and upper level
flow becomes more zonal. Climate Prediction Center`s 8-14 Day
Outlook for Nov 19-25th has 40-50% chance of above normal
temperatures over IL with equal chances of above and below normal
precipitation.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 552 PM CST Sun Nov 11 2018
VFR conditions are expected through 12z with a slow lowering
of the cigs expected on Monday with precipitation approaching
from the southwest. Looking for mainly mid level clouds tonight
which will gradually lower to low VFR with MVFR cigs expected
by late morning or early afternoon, excpt in PIA where we will
hold with low VFR cigs. We may see some light snow develop over
our west and southwest Monday morning with a better threat for
light snow at SPI, CMI and DEC late morning through the afternoon
hours. Light mostly northerly flow expected tonight will increase
out of a north to northwest direction on Monday with speeds of
10 to 15 kts
&&
.CLIMATE...
Issued at 300 PM CST Sun Nov 11 2018
Record Temperatures for Tuesday and Wednesday:
11/13 11/13 11/14
Coldest Coldest Coldest
Location Low (year) High (year) Low (year)
Champaign.... 7 (1986) 22 (1986) 10 (1986)
Charleston... 7 (1986) 24 (1986) 10 (1986)
Danville..... 9 (1986) 22 (1986) 10 (1976)
Decatur...... 7 (1986) 22 (1986) 8 (1986)
Effingham.... 9 (1986) 27 (1940) 9 (1986)
Galesburg.... 4 (1986) 18 (1986) 8 (1940)
Jacksonville. 7 (1986) 25 (1940) 7 (1986)
Lawrenceville 17 (2013) 29 (2014) 18 (2014)
Lincoln...... 5 (1986) 27 (1995) 7 (1986)
Normal....... 5 (1986) 21 (1940) 7 (1940)
Olney........ 10 (1920) 29 (1911) 12 (1940)
Paris........ 9 (1986) 24 (1986) 10 (1986)
Peoria....... 5 (1986) 22 (1986) 8 (1940)
Springfield.. 7 (1986) 23 (1986) 12 (1940)
Tuscola...... 8 (1986) 26 (1986) 10 (1986)
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...07
LONG TERM...07
AVIATION...Smith
CLIMATE...37
Area Forecast Discussion
National Weather Service San Francisco Bay Area
355 PM PST Sun Nov 11 2018
.SYNOPSIS...Smoke will continue to impact the area through
Monday with dry conditions and light offshore winds continuing.
Seasonably mild with continued dry weather through much of the
upcoming week through next weekend. A possible pattern shift by
Thanksgiving.
&&
.DISCUSSION...as of 1:45 PM PST Sunday...Smoke impacts from the
Camp Fire continue to be the main weather item of note across the
Bay Area. Red Flag Warning remains in place through 4 pm today.
Strongest offshore winds will ease as daytime heating is lost.
However very dry conditions continue across the region with low
humidity values. Currently the main smoke plume from the Camp Fire
is pointed towards northern Sonoma County. Forecast wind flow will
then bring much of the smoke southward across the Bay Area. Latest
18z hrrr smoke model keeps vertically integrated smoke values
elevated through Monday for much of the Bay Area. Keep in mind any
changes in fire activity will obviously change the potential
smoke impacts but for now expect air quality impacts at least
through Monday for much of the Bay Area. Smoke is also impacting
high temps with most sites staying in the upper 60s to lower 70s.
The smoke is enough to shave at least a few degrees off the model
guidance.
In the short term we are seeing some of the northeast winds mix
down into the valleys this afternoon with northeast wind gusts to
28 mph at Oakland Airport. Large scale gradients are easing with
only 10 mb offshore now thus lighter winds tonight in the hills.
Large scale pattern keeps a solid ridge over CA at least through
Weds. This will keep warm and dry weather in place but widespread
smoke could inhibit some of the warming potential. Nonetheless
still expect daytime highs upper 60s to mid 70s.
The ridge may weaken by Thursday but the pattern remains tranquil.
Expect dry and seasonable weather Thursday through the upcoming
weekend. Models have been consistent in changing to a more active
or at least zonal type flow starting next week. The ecmwf has a
weak shot of some light rain by around Nov 19th with better
chances around Nov 21-22nd. However confidence remains low to
medium overall on details in terms of rainfall but higher
confidence in temps at least dropping back to near or slightly
below normal around Thanksgiving.
&&
.AVIATION...As of 3:55 PM PST Sunday...For 00z TAFs. Smoke
continues to impact area terminals this afternoon with scattered
to broken cigs and reduced vsbys across the region. Slantwise
vsbys have been a major issue and will continue to cause problem
during approach and result in delays in air traffic for the next
24 to 36 hours. Light offshore winds will continue through much of
the period.
Vicinity of KSFO... Moderate NE winds will persist through this
afternoon and then will ease after sunset. Will keep 6sm HZ FU and
Few-Sct030-035 in the TAF through the period as a result of the
smoke.
SFO Bridge Approach...Similar to KSFO. Major smoke impacts due to
slantwise problems. Not seeing much improvement as upstream smoke
remains thick.
Monterey Bay Terminals...Light winds will turn easterly this
evening and persist through the overnight hours. Smoke will
continue to bring reduced vsby and possible cigs.
&&
.FIRE WEATHER...As of 1:45 PM PST Sunday...Red Flag Warning
remains in effect through 4 pm Sunday. Lighter offshore winds will
continue tonight into Monday. Humidity recovery will continue to
be very poor in the hills, generally under 30 percent. Warm and
dry weather with continued light offshore flow at least through
midweek will keep fire weather conditions near critical but no
strong wind events are forecast. Fuel conditions remain at record
dry levels. No rain forecast at least through next Sunday.
&&
.MARINE...as of 03:39 PM PST Sunday...Northerly to easterly winds
will persist over the coastal waters as high pressure remains
locked in place through tonight. Light southerly winds will
develop on Monday before transitioning back out of the northwest
by midweek. Small swells will continue before a northwest swell
builds by midweek.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...None.
&&
$$
PUBLIC FORECAST: RWW
AVIATION: CW
MARINE: MM
FIRE WEATHER: RWW
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Area Forecast Discussion
National Weather Service Reno NV
545 PM PST Sun Nov 11 2018
.UPDATE...
The lake wind advisory for Lake Tahoe has expired. Winds are
diminishing across the lake, but choppy waves will continue
through this evening. Otherwise, the forecast remains on track,
with a cold night expected. CL
&&
.PREVIOUS DISCUSSION... /Issued 109 PM PST Sun Nov 11 2018/
SYNOPSIS...
High pressure will lead to dry and stagnant conditions through at
least Thursday. Localized air quality issues are possible under
valley inversions. Some smoke from California may filter into the
Sierra starting Tuesday if fires remain active. A pattern change
next week may open the door to a couple weak storms but no major
precipitation events are anticipated.
DISCUSSION...
* Today`s weather has been characterized by a super dry airmass
and strong east winds at ridgetop levels. Some of this wind is
making it down to Lake Tahoe with gusts above 30 mph. Latest
HRRR has winds relaxing after 6 PM so will extend lake wind
advisory until then.
* Strong and persistent ridging will overspread the region Monday
through much of this week. This leads to classic air stagnation
conditions in valleys with morning inversions, low mixing
heights, and weak transport winds. Air quality issues from local
sources remain possible. Transport winds generally E/NE but
simulations show some W winds starting Tuesday over the Sierra
which could bring some CA fire smoke into those regions.
* Simulations all show a pattern shift next week with a series of
troughs taking bites out of the persistent ridge. So we could
see a couple storms, likely in a weak or decaying phase, next
week. No atmospheric rivers showing up so any storms would
probably produce just light precip, gusty winds. Peak holiday
travel next week, however, does up the impact potential from
even just weak storms.
-Chris
AVIATION...
Expect VFR conditions at regional terminal areas today.
Northeasterly winds will continue with occasional surface gusts
15-20 kts possible this afternoon. Winds continue to blow atop
the Sierra crest, with current observations indicating gusts 45-55
kts. Turbulence is possible over and west of the Sierra this
afternoon and early this evening. Surface winds will decrease
after sunset, with wind gusts to 30 kts still possible along and
west of the Sierra crest overnight into Monday. Smoke from
California fires will remain west of the Sierra crest today and
tonight due to northeasterly flow.
For Monday and Tuesday, high pressure will move onshore across the
western US, which will cause winds to diminish at the surface and
aloft. Westerly flow aloft may allow smoke to be transported across
the Sierra, which could make for hazy skies, especially if fires
remain active in California. -Johnston
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Sacramento CA
318 PM PST Sun Nov 11 2018
.SYNOPSIS...
Dry weather continues with cool nights and near to above normal
days through the week. Critical fire weather conditions continue
through Monday morning, with breezy winds and low humidity.
Widespread smoke from the Camp Fire will continue to impact much
of the area.
&&
.DISCUSSION...
Latest satellite imagery shows interior NorCal on the east side of
a persistent upper ridge over the eastern Pacific. Widespread
smoke and haze continues to envelop the region due to the Camp
Fire. Current observations indicate Valley gusts up to 25 mph, and
local wind gusts of 30 to 40 mph over the mountains. Gradient is
trending down, with lighter wind expected by Monday afternoon.
Winds will gradually diminish across the Valley tonight as
pressure gradient relaxes. Gusty wind will persist over the
eastern foothills/mountains through Monday morning, then lighter
wind is anticipated in the afternoon. The combination of wind, low
humidity, and near record dry fuels is bringing critical fire
weather conditions. Therefore, a Red Flag Warning is in effect for
the Central Sacramento Valley southward until 9 PM, and until
Monday morning for higher elevations.
Wildfire smoke continues to be an issue, with poor visibility for
some spots, and bad air quality. Latest HRRR smoke forecast
indicates smoke continuing to impact the region mainly from Chico
southward, with some improvement on the west side of the Valley.
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. Make sure to check on sensitive groups, and go to
airnow.gov for air quality information.
The region will remain under the influence of a persistent upper
ridge, resulting in dry weather. Smoke might help to keep
temperatures cooler the next couple of days. High temperatures
will be in the 60s to mid 70s for the Central Valley, with mostly
50s to 60s for the foothills and mountains. Cold overnight
temperatures are expected mainly over the Central Sacramento
Valley southward, with lows in the 30s. Lows will be in the 10s
to low 20s across mountain basin locations.
&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)
Broad upper ridge forecast to continue across the region later in
the week maintaining dry weather with mild days and cool nights,
and no strong wind events are expected. Forecast guidance is
indicating the possibility of a pattern change as an upper trough
approaches the area late next weekend into early next week.
However, confidence in details remains low so have kept the area
dry for now.
&&
.AVIATION...
Widespread MVFR with local IFR expected to continue next 24 hours
south of KCIC as smoke continues to spread southward from the
Butte County wildfire. VFR to the north of KCIC and over the
higher elevations of the Sierra Nevada. Local northerly wind gusts
to 25 kts over far west side of the valley will decrease after
02Z. Local northeast wind gusts to 30 kts will continue over the
west slopes northern Sierra Nevada.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 AM PST Monday for Northern Motherlode
From 1000 to 3000 Ft. Includes portions of Nevada-Yuba-Placer-
Amador and ElDorado Units-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-Southern Motherlode From 1000 to
3000 Ft. Includes portions of Calaveras-Tuolumne Unit-Stanislaus
NF West of the Sierra Crest.
Red Flag Warning until 7 AM PST Monday for Burney Basin and
Northeast Plateau in Shasta County Including Northwest Lassen NF
north of Lassen NP-Eastern Mendocino NF-Eastern Portion of
Shasta/Trinity NF-Lake County Portion of Lake-Napa-Sonoma Unit-
Northern Sacramento Valley to Southern Tehama County Line Below
1000 Ft-Southeast Edge Shasta-Trinity NF and Western Portions of
Tehama-Glenn Unit.
Red Flag Warning until 9 PM PST this evening for Carquinez
Strait and Delta-Central Sacramento Valley in Glenn, Colusa,
Yuba, Northern Sutter, and Butte County Below 1000 Ft-Southern
Sacramento Valley in Yolo-Sacramento Far Western Placer,
southern Sutter and Solano County Below 1000 Ft.
&&
$$
Area Forecast Discussion
National Weather Service Topeka KS
816 PM CST Sun Nov 11 2018
.UPDATE...
Issued at 816 PM CST Sun Nov 11 2018
Precip has been slow to develop due to low level dry air and
temperatures have remained warmer than expected early this
evening. Since snow was expected to have already begun across much
of the area by now, think snow totals could end up being a little
lower than previously forecast. Adjusting the forecast just for
the temps and delaying the change over to snow has lowered totals
along interstate 70 across the northern portions of the advisory.
Will keep the advisory going as is, but back off slightly on snow
amounts. It still looks as if east central KS, or areas southeast
of a line from Council Grove to Topeka, could end up with 1 to 3
inches. The main shortwave is just know beginning to move out into
the high plains of NM so there remains some decent dynamics to
lift across the area overnight and Monday morning. This is where
the 00Z NAM is now showing a second band of precip through the
morning.
&&
.SHORT TERM...(This evening through Monday)
Issued at 348 PM CST Sun Nov 11 2018
A potent band of snow sets up along and south of Interstate 70
this evening into Monday, producing a swath of 1-3 inches of snow
with locally higher amounts towards the I-35 corridor.
The synoptic setup early this afternoon features a sharp,
positively-tilted upper-tropospheric trough diving into the Four
Corners region, with resulting H500 height falls and increasing
290-300K isentropic upglide fueling a wide swath of precipitation
over western Kansas. Increasing 750-650mb frontogenetical forcing
was leading to banding features both within the snow shield in
western Kansas and now further east over the last few hours along
a northwest-to-southeast-oriented swath between Wichita and
Emporia. Despite warming up into the low to mid 40s, dynamic
cooling within this band is dropping surface temperatures into
the upper 30s and wet bulb values to near freezing, allowing for
at least a mixture of rain and snow to be observed. The
development of this band was modeled modestly well by the 12Z CAM
suite, with the NAM core models (NMM/NAMNest) doing the best in
defining the banded nature of the precip shield and the resulting
cooling occurring under it.
The best juxtaposition of isentropic upglide, coupled with mid-
level frontogenetical forcing under a region of negative EPV
within the DGZ, is still on track to occur late this evening
along and south of I-70. Most CAMs generating two to three tenths
of an inch of 6 hourly QPF with this band, with minor variability
noted in its placement between the various solutions. This could
easily produce a short-period of 1"+/hr snowfall rates in the
strongest bands. The transient nature of this lift means that any
deviations in its timing or location will have a significant
impact on snowfall amounts. There will likely be a sharp cutoff in
snowfall amounts north of the I-70 corridor, with barely
measurable snowfall totals expected near the Nebraska border.
The other big question will be how quickly the near surface
thermal profile cools to support snow. Given how quickly the
transition to snow occurred in central Kansas earlier this
afternoon, updated the hourly weather forecast to skew the
rain/snow threshold to 42/38 degrees. With dewpoints still in the
low 30s and wet bulb values in the mid 30s, it is expected that
the initial wave of snow will melt and have minimal impacts on the
roads. However, as the profile continues to cool and slightly
drier air funnels in from the north, snow accumulation will
commence quickly beginning near 00Z. Did make some minor
adjustments to the start time/location of the winter weather
advisory to account for the orientation of this snow band.
The bulk of the mesoscale forcing wanes after 06Z with continued
kinematic lift maintaining a broad swath of light snow over much
of the area through 12Z. A deepening DGZ on the order of
1000-1500m thick should allow this modest lift to still produce
up to another inch of snow before sunrise. As an embedded PV lobe
ejects northeastward from the base of the H300 trough early Monday
morning, the 700mb baroclinic zone pivots over southeastern
Kansas, keeping a continued threat for snow going throughout the
day in the southeastern forecast area. The NAM is quite aggressive
in snowfall rates within this band during the day Monday--with
6-7 inches depicted in Garnett using the Cobb snowfall technique--
and this potential will need to be watched closely. Did extend the
winter weather advisory until 00Z tomorrow in the southeastern
forecast area to account for these impacts. Increasing CAA ahead
of an approaching ridge finally ushers this system out of the area
around sunset Monday evening.
The other concern for Monday revolves around the potential for
horizontal convective roll processes to develop and produce banded
snow squalls behind this main complex over north-central and
northeast Kansas. The 12Z NAM is the most aggressive in this
scenario, depicting a deeply mixed boundary layer over 1-km in
depth with upright surface convective instability noted under the
H825 inversion. Both RAP and NAM forecast soundings contain winds
of 25 to 30 kts at the top of the mixed-layer, the top of which
extends into the lower DGZ and would support snow as the primary
precip type. The increasing dewpoint depressions at the surface
may aid in sublimating some of the snow before it reaches the
ground. For this reason, have kept only the mention of flurries
throughout the day across the forecast area. However, any stronger
HCRs, coupled with the blustery winds, could bring brief,
localized periods of travel difficulties. These snow showers wane
as diurnal heating lessens in the afternoon and evening.
.LONG TERM...(Monday night through Sunday)
Issued at 348 PM CST Sun Nov 11 2018
Little sensible weather is forecast for the rest of the week with
temperatures lingering below normal.
A sharp meridional upper-tropospheric longwave trough will be
positioned overhead at the start of the period, with
split/northwesterly upper flow ensuing for the bulk of the work
week. A 1030mb surface high pressure cell becomes the dominant
feature over the central plains by Tuesday, with continued CAA
ahead of the ridge pushing lows down into the teens Monday night.
The ridge passes east of the forecast area by late Tuesday, with
weak southerly flow setting up for Wednesday and Thursday. Recent
EC/GFS/GEM runs have backed off on the strength of the downslope-
induced H850 thermal ridge for midweek, with the resultant surface
highs slipping five to eight degrees lower than what was forecast
yesterday. The H500 ridge translates through the region on
Thursday, with height falls on the backside of the ridge
facilitating the passage of a weak surface trough devoid of precip
on Thursday night. The upper-level pattern over the western CONUS
amplifies for late in the week, with an increasing threat of
transient PV lobes bringing light snow to the region; however,
confidence in the timing and location of these disturbances over
the weekend is low and there is a large spread in the longer
range guidance.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday)
Issued at 527 PM CST Sun Nov 11 2018
Most of the guidance suggests the terminals should be on the
northern fringes of the main snow band tonight with some dry air
in place that needs to be overcome. With this in mind, have a VFR
forecast for a few hours into the evening. Think the main window
for some MVFR conditions and -SN is between 03Z and 07Z. After
07Z the banded precip is expected to shift southeast. The next
wave of energy is progged to move across southeast KS by 12Z. This
could bring some -SN back into TOP and FOE mid morning. Then
forecast sounding develop steep low level lapse rates during the
day Monday suggesting some potential for snow showers. Confidence
is marginal in both these things bringing SN into the terminals
so have a VCSH for now.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM CST Monday for KSZ040-054>056-
058-059.
Winter Weather Advisory until 6 AM CST Monday for KSZ021-022-026-
034>039.
&&
$$
UPDATE...Wolters
SHORT TERM...Skow
LONG TERM...Skow
AVIATION...Wolters
Area Forecast Discussion
National Weather Service Tulsa OK
927 PM CST Sun Nov 11 2018
...UPDATE...
.DISCUSSION...
Precipitation continues to expand from eastern NM through the TX
Panhandle and extending across southern KS. A notable uptick in
precipitation intensity has been observed across the TX Panhandle
with recent reports of thundersnow, and this band of associated
forcing will begin to extend eastward overnight with an expected
increase in precip into NE OK late tonight. Additionally, the
widespread ongoing convection over E TX will gradually lift
northward into SE OK later tonight before spreading more east of
the forecast area early Monday.
Regarding the winter weather potential, the recent operational
HRRR runs have verified well with the sfc freezing line, where as
the recent 00z NAM showed considerable error across western KS
with its 3HR fcst. This trend will be closely followed as the
aforementioned NAM run is more aggressive with the freezing line
south of I-44 during the the period of strongest lift around mid
morning Monday. Also, data trends have been more northward with
the mid level dry intrusion which, if verified, would quickly
limit the snow potential southeast of Interstate 44 during the day
Monday. In typical fashion, Southern Plains winter event are
seldom straight forward. The updated forecast will adjust for
precip coverage trends through the early morning hours otherwise
the overnight forecast remains on track.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 34 35 18 35 / 60 100 10 0
FSM 36 38 26 38 / 70 100 20 0
MLC 36 37 23 36 / 70 100 10 0
BVO 31 32 17 37 / 70 100 10 0
FYV 34 35 21 33 / 50 100 20 0
BYV 34 35 20 33 / 40 100 20 0
MKO 35 36 21 35 / 60 100 10 0
MIO 33 34 18 33 / 60 100 10 0
F10 35 36 21 36 / 60 100 10 0
HHW 39 40 27 39 / 80 100 10 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Winter Weather Advisory from 3 AM to 6 PM CST Monday for
OKZ054>067.
AR...Winter Weather Advisory from 3 AM to 6 PM CST Monday for ARZ001-
002-010-011.
&&
$$
SHORT TERM...07