Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/08/18
Area Forecast Discussion
National Weather Service Albany NY
923 PM EST Wed Nov 7 2018
.SYNOPSIS...
Seasonable temperatures are expected tonight into tomorrow with
mainly dry conditions. A storm system will bring some rain and
mountain show to the the region for Friday into Friday night. Cool
and breezy conditions are expected over the weekend, with some lake-
effect snow showers for western and northern areas.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 920 PM EST...A broad upper level trough extends from the
northern Plains eastward across the Midwest and Great Lakes.
Although the low level flow is out northwest, there is generally
west to southwest flow aloft. Some cold air advection has been
occurring throughout and with the colder air passing over Lake
Ontario, some light lake-effect showers have been impacting
parts of the western Adirondacks. With boundary layer temps warm
enough, this precip has been falling as rain showers. However,
surface temps will be falling and this on and off light precip
may changeover to snow showers for the overnight. Both the 3km
NAM Nest and HRRR suggest the flow will remain fairly steady
state, so basically areas north of Old Forge and Indian Lake may
see some light snow showers through the overnight. Any
accumulation looks fairly light, generally under an inch.
Outside of the lake-effect activity, it will remain partly to
mostly clear and seasonably chilly for tonight. Some cirrus
clouds moving up from the mid-Atlantic are expected for southern
areas, but it should stay dry. A decreasing pressure gradient
and nocturnal effects should help reduce winds for tonight after
some gusts this evening of up to 24 kts with the passage of a
weak trough of low pressure. Lows will generally be in the 30s.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Some additional lake-effect rain or snow showers will continue
across the western Adirondacks for Thursday (mainly early in the
day). Otherwise, the weather will remain fairly similar, with a
broad trough located just west of the region keeping it fairly
dry with a partly cloudy sky. Temps will be cooler on Thursday
compared to Wednesday thanks to chillier temps aloft, with highs
only reaching into the 40s.
High pressure will move across the region for Thursday night,
allowing any lake-effect precip to end and skies to be partly to
mostly clear. Lows will be in the upper 20s to mid 30s.
The next storm system will be arriving for Friday. As a
shortwave dives out of Canada into the trough, it will sharpen
and cut off over the Great Lakes. Meanwhile, a surface storm
over the Ohio Valley will be lifting towards the eastern Great
Lakes, while a secondary low develops off the mid-Atlantic
states. This system will tap into some Gulf moisture. While it
may be dry early in the day Friday, precip will expand across
the region for later Friday morning and through the rest of the
day. Valley areas will mainly see rain (cannot rule out a few
snowflakes to start, but no accumulation). Meanwhile, high
terrain areas (above 1500 feet) will see rain and snow, but any
snow accumulation looks limited to areas above 2500 ft, as the
southerly flow at the surface allows some warmer air to move
northward within the boundary layer. The highest terrain of the
Adirondacks and southern Greens may see a few inches of snow
accumulation from this storm.
As the storm along the coast deepens, frontogenesis along the
coast could allow for some heavier precip, so cannot rule out
some moderate to locally heavy rain, especially for southeastern
areas. Precip looks to be tapering off on Friday night after
midnight, as the secondary low lifts towards coastal Maine.
Nearly steady temps in the mid 30s to mid 40s are expected for
Friday into Friday night.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The long term forecast period starts out active and ends active with
some drier weather during the middle of the long term period.
On Saturday expect some measurable lake effect snow downwind of Lake
Ontario across the western Adirondacks with some scattered rain or
snow showers across the Mohawk Valley, Lake George Saratoga region,
southern Vermont, and the northern Berkshires. H8 temps are -4 C to
-8 C with Lake Ontario temp still around 10 C, so plenty of
differential to work. A this time expect generally 1 to 4 inches of
snow across the western Adirondacks with the greatest accumulation
along and north of Route 28. Highs on Saturday are expected to be in
the upper 20s to mid 40s.
On Saturday night the lake effect band shifts south into the
southern portions of the western Adirondacks as well as the Mohawk
Valley and Schoharie Valley. Accumulations look to be light at this
time, but up to another inch of snow accumulation is possible. Lows
will be in the upper teens to upper 20s.
Sunday through Monday...Looks to be mainly dry as a large ridge of
high pressure builds across the eastern seaboard. It will continue
to be chilly with highs on Sunday in the upper 20s to lower 40s with
lows Sunday night in the mid teens to upper 20s, and highs on Monday
in the upper 20s to mid 40s.
More active weather is expected Monday night into Wednesday as low
pressure moves east from the upper Great Lakes as a secondary area
of low pressure is expected to form along the middle Atlantic coast
on Tuesday morning. A secondary trough of low pressure is then
expected across the region on Wednesday bringing more cold air to
the region. Lows Monday night are expected to be in the mid 20s to
mid 30s with highs on Tuesday in the mid 30s to mid 40s. Lows
Tuesday night are expected to be in the upper teens to lower 30s
with highs on Wednesday in the mid 20s to around 40.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR conditions are expected to prevail over the next 24 hours ending
00Z Friday. Some intervals of low and high clouds are expected
through the period along with steady west to southwest winds.
The periods of low and high clouds and steady winds should
prevent any widespread fog through tonight and early Thursday
morning.
Winds diminish to less than 10 kts from the southwest tonight
then increase to around 10 kts from the southwest to west Thursday
morning. The exception will be at KALB, KGFL and KPSF where
winds will be west to northwest with gusts up to 24 kts this
evening.
Outlook...
Thursday Night: No Operational Impact. NO SIG WX.
Friday: High Operational Impact. Definite RA.
Friday Night: High Operational Impact. Definite RA.
Saturday: Low Operational Impact. Breezy Slight Chance of SHRA.
Saturday Night: No Operational Impact. NO SIG WX.
Veterans Day: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: Low Operational Impact. Slight Chance of SHRA.
&&
.FIRE WEATHER...
Mainly dry conditions are expected tonight into tomorrow. RH
values will be as low as 50 percent on Thursday with northwest
winds of 5 to 10 mph. A wetting rainfall is expected across the
entire area on Friday into Friday night.
&&
.HYDROLOGY...
Outside of a few lake effect rain and snow showers over the
western Adirondacks, dry weather is expected across the area for
tonight through early Friday morning. Rivers and streams have
been rather elevated due to recent rainfall (especially across
western New England) and this period of dry conditions will
allow for water levels to slowly recede.
More rain (and some mountain snow) is expected to return for
Friday morning through Friday night. Total QPF is currently
forecasted to be 0.75 to 1.25 inches across the region, which
should allow for more rises on rivers and streams. Current
river forecast and MMEFS solutions show some rivers may reach
action stage (especially the Hoosic and Housatonic Rivers), but
no flooding is currently forecasted. If QPF were to increase,
then some minor flooding would be possible, so continue to check
for any changes in the forecast over the next few days.
Behind this system, colder and drier conditions (outside of
some lake effect snow showers for northwestern areas) are
expected over the weekend. River and stream levels levels should
slowly recede.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis
NEAR TERM...Frugis/11
SHORT TERM...Frugis
LONG TERM...11
AVIATION...11/NAS
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service La Crosse WI
546 PM CST Wed Nov 7 2018
.SHORT TERM...(This evening through Thursday)
Issued at 237 PM CST Wed Nov 7 2018
Flurries and even some freezing drizzle in the higher elevations
were seen along and east of the Mississippi River Wednesday
afternoon as a shortwave trough continued to rotate through the
northwest flow aloft. At the surface, a fairly tight pressure
gradient brought gusty northwesterly winds to the area, though these
should subside a bit as high pressure continues to build in
overnight. The high pressure should also be enough to break up the
persistent cloud cover at least a little bit, but the RAP has
trended toward keeping the clouds around all night, which could lead
to temperatures being a few degrees higher than forecast.
Thursday will then be quiet as high pressure continues to build in,
but clouds will be on the increase through the afternoon.
Temperatures will remain cool, with highs in the 30s.
.LONG TERM...(Thursday night through Wednesday)
Issued at 237 PM CST Wed Nov 7 2018
Attention then turns to snow chances Thursday night through Friday.
Good model agreement of shortwave energy ejecting eastward out of
the Central Plains Thursday evening. In addition, should be some
decent mid-level frontogenesis in the area, but not great agreement
as to where it initially sets up. 07.12Z NAM/ECMWF/Canadian develop
the band to the northwest and slide it through the entire area. In
contrast, the 07.12Z GFS develops it directly over the forecast
area, keeping northwest portions of the area dry. Bottom line,
should be a band of light snow (an inch or less) that moves through
at least part of the forecast area through Friday morning.
Meanwhile, a broader upper level trough will drop southeastward out
of North Dakota and spin up a surface low. This will bring more cold
air to the region (highs in the upper 20s to mid 30s). Also, more
snow is expected with this system through Friday afternoon, mainly
along and west of the Mississippi River. Once again, model
differences in placement don`t allow for much confidence in the
forecast, but northeast Iowa looks to have the best shot for more
snow. In addition, there is good model agreement of a fairly tight
pressure gradient over the area, so should some pockets of heavier
snow develop, strong winds could lead to some temporary travel
issues. All snow should come to an end by Friday evening, with
totals from Thursday night through Friday being generally in the 1
to 2 inch range.
Zonal upper level flow will then set up for the weekend, with more
bits of shortwave energy sliding through Saturday night and possibly
bringing some light snow or flurries. Sunday will see a slight
"warmup" with highs into the 30s area-wide. A return to upper level
troughing is then on tap for the beginning of the work week, with
more cold air spilling in from the north. There are also hints of
more light snow with this, though surface high pressure will quickly
build in Monday night into Tuesday, keeping the area dry through the
remainder of the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 545 PM CST Wed Nov 7 2018
The 00Z TAF set will have significant delay to the MVFR
conditions overnight from the previous forecast. Took a more
pessimistic approach based on satellite expanse of the OVC MVFR
CIGS over all of MN/IA and slowly shifting east. Also, PIREPS
indicating the cloud depth is about 1500ft over the area,
thinning to around 1kft on western cloud edge. 1500 ft would
indicate a tougher mix out of the clouds via subsidence.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...CA
LONG TERM...CA
AVIATION...Baumgardt
Area Forecast Discussion
National Weather Service Burlington VT
955 PM EST Wed Nov 7 2018
.SYNOPSIS...
A slow cooling trend continues across the North Country with
scattered mainly mountain rain and snow showers. Temperatures
tonight drop into the mid 30s to lower 40s with highs on
Thursday warming into the upper 30s to upper 40s. Low pressure
will track toward our region on Friday into Saturday, with a mix
of rain and snow. Some snow and ice accumulation is likely in
the mountains, with limited accumulation anticipated in the
warmer valley locations. Temperatures will cool into the 30s to
lower 40s with overnight lows holding in the upper 20s to mid
30s.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
As of 955 PM EST Wednesday...Starting to see flow aloft
becoming more westerly tonight and this is helping to decrease
the areal coverage of lake effect precipitation with just some
isolated showers moving across the area. Going forecast has this
decreasing trend handled well and only tweaks needed were to
match temperature and dew point trends.
Previous Discussion...
Mid/upper level trof continues to deepen across the ne conus
with fast westerly flow aloft as VAD 500mb winds show values of
90 to 110 knots. Water vapor and RAP show weak embedded 5h vort
entering the slv and better 850 to 500mb moisture slowly
advecting south to produce isolated to scattered shower
activity. This general idea of chc pops mainly across the
mountains looks reasonable based on moisture/lift thru 06z. In
addition, aligned 925mb to 850mb west/southwest flow of 35 to 45
knots will help to advect better lake moisture into the dacks,
along with enhanced upslope flow to produce likely pops for this
evening. As better dynamics shifts east and winds slowly become
west/northwest expect moisture to decrease in areal coverage,
along with precip chcs. A light dusting of snow is possible
above 2000 feet over the dacks and northern Green Mountains.
Temps will range from the mid 20s summits to lower 40s warmer
valleys. Still expecting some gusty winds this aftn with kmss
gusting to 37 knots, these winds will decrease aft sunset as low
levels stabilize and pres gradient slowly weakens.
For Thursday into Thursday...weak sfc high pres and mid/upper level
ridge builds across our cwa. Deeper rh profiles show good drying
aloft, however with bl moisture, 5h energy and moisture trapped
below 850mb, expect mostly cloudy skies in the mountains and partly
sunny valleys. A few isolated rain/snow showers are possible, but
areal coverage based on moisture profiles will be minimal. Temps
range from the upper 20s/lower 30s summits to mid/upper 40s valleys
on Thursday. Thursday night will be quiet and chilly as 1030mb high
pres builds into our fa. The uncertainty will be amount of clearing,
as winds will become light and trrn driven. Clouds will have a
significant influence on sfc temps with initial thoughts lows
ranging from mid 20s to mid 30s most locations.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 345 PM EST Wednesday...Overall little change from what
we`ve been highlighting for the end of the work week and into
the first half of the weekend. Expect we`ll see a widespread
precipitation event Friday through Saturday with varying
precipitation types in the higher elevations and rain in the
valley floors. On the broad scale, a full latitude CONUS trough
will by digging through the Great Plains and becomes closed off
over the Great Lakes on by Saturday. As that upper level low is
deepening a surface low develops over the Ohio Valley and pushes
up through the Saint Lawrence Valley during the day on Friday.
At the same time another surface low develops along the Atlantic
coast to create the double barrel low structure that guidance
has been keying on for a couple of days now. This setup will
bring widespread warm air advection precip to the region which
will mostly fall in the form of rain.
Because the upper level dynamics are stronger with the northern
stream low I would expect that one to intensify more than is
currently forecast and for the coastal low to be weaker. That
points to a slightly more warm solution with slightly less snow.
Guidance still points to a warm nose pushing into the region
briefly Friday afternoon which should be enough to cause some
mixed precip issues. However the differing ptypes will be above
2000 feet so largely the effects will be minimal where most
people live. Still a tad early for exact details but the best
chance for snow should be over the Adirondacks with the highest
potential for ice accumulation in the high peaks of the
Adirondacks and the Greens.
By Saturday morning, the precipitation becomes more showery and
we`ll start to see some mountain showers along with a lake
effect response. Precip tapers off Saturday night as the low(s)
pull farther northeast of the region and high pressure begins
to build in from the west/southwest.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 401 PM EST Wednesday...Cold temps and quiet weather
return Sunday into Monday as high pressure builds in. Expect
temps to stay on the chilly side Sunday as we`ll be mostly
overcast skies under cold air advection. This pattern is typical
where the temp at like 9am or 10am in the morning holds steady
through out the day. So I dropped temps by a couple degrees and
that puts our highs in the upper 20s to low 30s. By mid week
another strong low pressure system looks to lift north bringing
another round of precip. The difference this time is that temps
will start off much colder and so we`ll see a period of snow
before the warm air finally overrides and transitions the North
Country back to steady rain.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...Overall looking at VFR conditions through
the period. Some lake effect rain showers from Lake Ontario may
reach KSLK and cause some MVFR conditions through 06z before
precipitation moves south of the area. Gusty west to southwest
winds will continue with gusts in the 15 to 25 knot range
through about 12z before the gusts taper off and winds remain
from the west around 10 to 15 knots.
Outlook...
Thursday Night: VFR. NO SIG WX.
Friday: Mainly VFR, with local MVFR possible. Definite RA.
Friday Night: Mainly MVFR, with local IFR possible. Definite RA.
Saturday: Mainly VFR, with local MVFR possible. Chance SHRA,
Chance SHSN.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHSN.
Veterans Day: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. Slight chance SHSN.
&&
.MARINE...
Lake wind advisory remains in effect tonight for southwest
winds of 15 to 25 knots and gusts to 30 knots. Expect localized
wave heights near 4 feet in the open waters and this will create
rather choppy conditions.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Taber
NEAR TERM...Evenson/Taber
SHORT TERM...Deal
LONG TERM...Deal
AVIATION...Evenson/Taber
MARINE...Clay
Area Forecast Discussion
National Weather Service Lincoln IL
902 PM CST Wed Nov 7 2018
.UPDATE...
Issued at 852 PM CST Wed Nov 7 2018
Cloud deck hugging the I-74 corridor continues to inch southeast
early this evening and was not handled well by the operational
models. High resolution forecast soundings from the 3km NAM
suggest moisture in the 1200-2000 foot layer to be trapped under a
developing subsidence inversion overnight into Thursday morning.
Although the latest HRRR holds on to the clouds the longest over
the northern half of our forecast area, it appears the clouds
start to scatter out before dawn Thursday which looks to be too
quick based on the soundings. Will expand the cloud deck further
south for tonight to at least the I-72 corridor well after
Midnight. Based on the increase in cloud cover tonight, will edge
temperatures back up for overnight lows with morning lows in the
upper 20s to lower 30s.
The low clouds may scatter out late tomorrow morning as a
developing easterly flow draws in somewhat drier air in the low
levels with a weakening of the inversion noted on forecast
soundings. However, any decrease in the lower cloud cover will be
offset by increasing high level clouds as the day wears on ahead
of our next weather system. It still appears any rain and snow in
our area will hold off until tomorrow evening. Updated forecast
should be out by 915 pm.
&&
.SHORT TERM...(This evening through Thursday)
ISSUED AT 206 PM CST Wed Nov 7 2018
Quiet weather expected in the short term, as high pressure
continues to build southeast. With abundant dry air aloft,
Thursday looks to remain precip-free as the storm system starts to
approach from the southwest. Not looking for a lot of change in
temperatures for Thursday, though the far southeast CWA should be
about 5 degrees cooler than today.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 206 PM CST Wed Nov 7 2018
Overall pattern still remains unseasonably cold across the Midwest
into the middle of next week. Several deep upper troughs will
swing through the region, accompanied by shots of Arctic air (850
mb temperatures as low as -15C at times). The coldest day looks to
be Saturday, when highs may struggle to reach freezing over the
northern CWA, after an early morning featuring wind chills in the
single digits.
Shortwave currently over southern Idaho will help sharpen as it
swings into the Plains on Thursday. Latest model guidance
continues to show widespread precipitation over the forecast area
by mid evening, with model soundings suggesting a quick change
from rain to snow. Amounts around an inch or so still appear
reasonable over areas north of I-72 Thursday night, with the snow
shifting northeast early Friday morning. Clipper system behind it
will bring a quick shot of rain/snow across the north Friday
afternoon and evening, but no accumulations are expected with this
feature.
With the system early next week, the longer range models are in
good agreement with the upper level features, though the GFS is a
bit faster with the progression of the upper trough. The
precipitation shield is a much different story, though, as the
European (especially) and Canadian models have much more of a
deformation zone present. The GFS largely bypasses any precip for
our area. Will mainly focus PoP`s on the Monday night time frame,
where another light dusting is possible.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 506 PM CST Wed Nov 7 2018
Significant changes already made to PIA and BMI bringing in MVFR
cigs over the next hour with the main question how far south the
lower cigs will get and how long they will be in our area
tonight/Thu morning. Recent runs of the HRRR model continues to
point towards a more pessimistic forecast for the overnight and
early morning hours with MVFR cigs spreading into our southern
TAF areas after Midnight before we see the clouds start to slowly
decrease during the mid-morning hours with VFR conditions expected
during the afternoon. Even that is in doubt as the latest 3km
soundings suggest moisture trapped below a subsidence inversion
around 2000 feet AGL late tonight through Thu morning may hold
the MVFR cigs longer than what is currently forecast.
Light northwest to north winds expected tonight should start to
veer more into a northeast then east direction on Thursday with
speeds of 10 kts or less.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Smith
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
753 PM CST Wed Nov 7 2018
.UPDATE...
Issued at 753 PM CST Wed Nov 7 2018
The RAP and HRRR models have ingested the 00z upper air data. A
blend of these models plus the HREF are in place for a new
snowfall forecast. The forecast suggests slightly less snow across
swrn Nebraska but slightly more across nrn Nebraska.
2 or 3 areas of snow are expected to affect parts of western and
north central Nebraska tonight and Thursday.
The area of snow underway across sern MT per radar may affect
highway 20 across northern Nebraska late tonight and Thursday. The
area of snow currently underway across sern WY may affect I-80
and the Sandhills later this evening, overnight and Thursday. The
area of snow underway across swrn Nebraska should exit that area
by 6 am Thursday morning.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 302 PM CST Wed Nov 7 2018
As a winter system crosses the area tonight, isentropic upglide
will be rather substantial across southwest and central Nebraska
overnight. Some potential for heavier banded convective snow,
given areas of negative EPV and even some weak elevated CAPE. The
upper jet axis is oriented from east central Co across the Nebr/KS
border. This places southwest and central Nebraska in the left
entrance region of the jet, which is less favorable for
divergence aloft. However, forecast model soundings do indicate
favorable saturation in the DGZ, so dendrite formation and growth
should be favorable. Snowfall overnight is expected to reach 1 to
3 inches in the winter weather advisory area, with additional
snowfall Thursday.
For Thursday, total snowfall amounts are similar to previous
forecast, with amounts from 4 to 6 inches south of a Grant through
North Platte and Brady. Within winter weather advisory area,
areas north of this line can expect 2 to 4 inches. Even into the
Sandhills of north central Nebraska such as Gordon, Valentine and
Ainsworth can expect up to an inch. Isentropic downglide kicks in
across the area by 15Z, with an en to the snow from west to east
during the day. Winds will remain light southeast around 5 mph
where snow continues Thursday, while becoming north across the
western Sandhills, where the snow ends. A cold day, with highs
from around 30 most areas.
.LONG TERM...(Thursday night through Wednesday)
Issued at 302 PM CST Wed Nov 7 2018
Much colder air drawn in Thursday night with some clearing skies.
Lows mostly reach the mid teens. Northwest winds increasing
overnight, becoming 15 to 20 mph across the north central, where
wind chills will fall to the low single digits most areas. These
low wind chills, even near 5 below Valentine and Gordon areas will
Occur Friday morning. Breezy conditions through the day east of
highway 83. With the winds, there will be patchy blowing snow,
especially for counties in and around Custer County. Highs only
around 20 parts of north central, to near 30 the Imperial area.
Upper level ridging will remain in place across the eastern Pacific
as we head into the weekend and first of next week. Northwest
flow aloft will prevail downstream across our region east of the
ridge. Some moderation in highs Saturday to the upper 30s to mid
40s, ahead of the next trough in the Northern Plains. expected
during the weekend, before another shot of cold air Monday with
highs upper 20s to lower 30s. A nice warm up by Wednesday into the
mid 50s as upper level ridging builds east. The extended period
looks mainly dry, with no significant weather disturbances noted.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 554 PM CST Wed Nov 72018
Across wrn and ncntl Nebraska...areas of MVFR/IFR in -SN and low
ceilings will become IFR/local LIFR overnight and improve to
MVFR/local IFR from west to east 00z Thursday evening.
2 or 3 areas of snow are expected to affect parts of western and
north central Nebraska tonight and Thursday. The area of snow
underway across sern MT may affect highway 20 across northern
Nebraska late tonight and Thursday. The area of snow currently
underway across sern WY may affect I-80 and the Sandhills later
this evening, overnight and Thursday. The area of snow underway
across swrn Nebraska should exit that area by 12z Thursday
morning.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM CST /5 PM MST/ Thursday for
NEZ036>038-056>059-069>071.
&&
$$
UPDATE...CDC
SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
701 PM EST Wed Nov 7 2018
.SHORT TERM...(This evening through Thursday)
Issued at 307 PM EST WED NOV 7 2018
WV imagery and RAP analysis indicated a broad mid/upper level trough
through the central CONUS leaving unseasonably cold air entrenched
across the region from the plains through the western Great Lakes. A
weak shortwave trough over central Upper Michigan was sliding
quickly to the east with no significant shrtwvs upstream that are
expected to impact the short term. At the surface, cyclonic
northwesterly flow persisted through the northern Great Lakes
between a ridge through the plains and low pressure over nrn Quebec.
850 mb temps to around -10C along with lingering deep moisture
supported relatively unorganized multiple wind parallel lake effect
snow bands into the nrn cwa with only brief periods of lower vsby
and only a few inches of accumulation over the higher terrain in the
west so far.
Tonight, the deeper moisture is expected to move out this evening
with inversion heights dropping to around 5k ft resulting in
diminishing LES. Additional accumulations of around an inch will
still be possible for nw flow favored locations. Although the LES
should end farther inland with loss of larger scale lift/moisture,
some low clouds will persist with exception over far southern
Menonminee county.
Thursday, expect some lingering nw flow LES as 850 mb temps remain
around -11C, even as sfc ridging builds into the area with
diminishing winds. Any additional accumulations should remain at a
trace or less an an inch. Under mostly cloudy skies, highs will
remain below average with readings in the upper 20s inland west to
the mid or upper 30s over the south and east.
.LONG TERM...(Thursday night through Wednesday)
Issued at 404 PM EST WED NOV 7 2018
Focus is on late Thu night into early Sat morning when significant
snowfall is possible.
Overall setup is for a sharp upper trough moving into the region Thu
night to possibly deepen into a compact low over the CWA Fri before
exiting E Fri night. At the surface, a trough will set up from the
lower Great Lakes across the U.P. and into Lake Superior. 850mb
temps will start out around -11C then cool to closer to -16C once
the upper trough/low moves through.
Moderate to heavy lake enhanced snow showers are expected in the
vicinity of the surface trough at first, then spreading as the upper
feature moves in. LES then takes hold Fri night behind the system
with N-NW winds, diminishing late Fri night through Sat. Snowfall
details depend on the track and strength of the upper forcing and the
tracking of the surface trough. The NAM is an outlier in showing a
stronger upper feature, and the surface trough more the SW, which
then leads to substantially more precip than other models. Staying
more toward the consensus leads to a few inches of snow over the S-
central U.P. and several inches elsewhere. Of course, if the surface
trough hangs over Lake Superior longer, snowfall amounts will be
lower. Snow ratios will likely be in the low to mid teens most of
Friday, increasing Fri night when the event transitions for pure
LES. Winds gusting to 30-40 mph at times may also lead to blowing
snow near Lake Superior. With the continued uncertainty, did not
issue any headlines at this time, but continue to highlight in the
HWO.
Beyond that, still seeing active weather with off and on chances for
lake effect snow, but nothing significant of any predictability.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 654 PM EST WED NOV 7 2018
While MVFR conditions are expected much of the time tonight,
there could be periods of IFR vsby under lake effect snow bands
at KCMX this evening. As snow diminishes to flurries to Thursday,
MVFR cigs will persist at all sites through much of the day,
except for the possibility of brief improvement to VFR at KSAW.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 307 PM EST WED NOV 7 2018
No gale events are expected through Thursday. Winds nw at 20-30 kts
are expected through Thursday as colder air moves across the Upper
Great Lakes. From Friday afternoon into Friday evening, n-nw winds
approaching gales could develop with a stronger push of cold air
into the region behind a cold front and strengthening low pressures
system.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...Voss
MARINE...JLB
Area Forecast Discussion
National Weather Service Pueblo CO
259 PM MST Wed Nov 7 2018
.SHORT TERM...(This evening through Thursday)
Issued at 237 PM MST Wed Nov 7 2018
An upper level trof will continue to slowly sink south toward CO
tonight, and will move over CO thru the day Thu. Western portions
of the forecast area are expected to remain dry tonight and Thu.
Eastern portions of the forecast area will see a lot of low cloud
cover tonight, and the potential for light precip. The HRRR shows
very little chance for precip tonight and Thu morning, with mainly
just some light precip over El Paso county before midnight. The NAM
shows a little more precip, mainly over El Paso county thru the late
night hours, and over the far southeast plains. The GFS shows
little precip, and mainly has precip from about the I-25 corridor
and west in El Paso/Teller county. The low level southeast upslope
flow in El Paso county may help get some light precip going, mainly
snow, but it is possible that there could be a little freezing
drizzle tonight. Precip increases a little in the models on Thu as
the upper trof approaches, but mainly over the far southeast plains.
Will still go with the potential for maybe around an inch of snow
over eastern portions of Kiowa county Thu morning. The GFS has
precip Thu afternoon over the Wet mtns and southern I-25 corridor,
while the NAM does not. Temps Thu are going to be well below
average, with highs mostly in the mid 30s to lower 40s over the
southeast plains and the Upper Arkansas River Valley, with lower and
mid 40s in the San Luis Valley.
.LONG TERM...(Thursday night through Wednesday)
Issued at 237 PM MST Wed Nov 7 2018
Operational models and ensemble members are in general agreement
into early next week with minor differences. This leads to overall
higher forecast confidence with large trough over the Central
Plains and ridge developing over the west. This will lead to
cooler conditions across the region into early next week.
Thursday night through Saturday...expect dry northwest flow
through this period with a couple of cold fronts impacting the
area, one on Friday and another on Saturday late in the day. As
for Friday, the frontal boundary will likely stall out across the
far Northeast Plains with cooler temperatures east of an Eads to
Lamar line. West of this area, highs on Friday will likely reach
into the upper 40s to lower 50s. East of the boundary highs will
likely only reach into the upper 30s to lower 40s.
By Saturday, flow aloft will transition westerly head of a
digging upper level trough out of the Northern Rockies. This will
allow much of southern Colorado to warm nicely Saturday afternoon
with upper 50s and perhaps a few low 60s across the Eastern
Plains. The next frontal boundary will push back west across the
Plains during the late afternoon hours into the evening. Much
colder air will work in behind the front with temperatures
falling into the lower to mid 20s by Sunday morning. Models
slightly different on precipitation timing as well. The GFS is
most aggressive with developing snowfall along the Palmer Divide
by Sunday morning.
Sunday through Monday...the next upper disturbance will drop south
across the region Sunday into Monday. As mentioned, the GFS is
slightly faster with snowfall onset with light snow into the
Palmer Divide region by Sunday morning. The ECMWF is slightly
slower and brings snow into the region by mid day. Expect at least
light rain and snow to develop over the mountain areas by Sunday
morning and expand eastward across the Plains Sunday night into
Monday. At this time, temperatures look like they could be cold
enough for snowfall, especially during the overnight hours across
the region. Afternoon highs on Sunday and Monday only look to
reach the mid to upper 30s, so during the daylight hours, there
could be rain and snow mixing across the lower elevations.
As for snow totals, its currently too early to tell. Both the GFS
and ECMWF have the heaviest snowfall banked along the Eastern
Mountains and Raton Mesa area where northeast upslope flow in the
lower levels is preferred. This will have to be monitored for
consistency in model runs. The main model differences are in
timing, with the GFS quicker to bring the system south into the
Southern Plains, while the ECMWF brings in a secondary surge
Monday night with another round of light snow clearing north to
south by Tuesday morning.
Tuesday and Wednesday...high pressure over the western states is
forecast to build east across the Rockies with drier and warmer
conditions expected across the area. Afternoon highs will warm
back into the 40s on Tuesday and 50s on Wednesday. Mozley
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 237 PM MST Wed Nov 7 2018
KALS is expected to see VFR conditions thru the forecast period.
KPUB will the ceiling lower this evening, with MVFR conditions
expected to develop and continue into about midmorning Thu. There
could be a few light snow showers tonight.
KCOS will see the ceiling lower this evening, with MVFR and maybe
even occasional IFR conditions until early Thu morning. Some light
snow will probably develop this evening and be possible thru the
night, there could be some light freezing drizzle at times. North
winds are expected to develop near 12Z on Thu and then the low
clouds should dissipate.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
Area Forecast Discussion
National Weather Service Tucson AZ
836 PM MST Wed Nov 7 2018
.SYNOPSIS...Dry conditions will continue into early next week.
Daytime temperatures will be several degrees above average today
then gradually cool into the upcoming weekend. A trough of low
pressure will bring additional cooling early in the new week.
&&
.DISCUSSION...Clear skies this evening with just a few cirroform
clouds across Sonora shifting eastward. Quiet weather will continue
through the overnight with seasonable temperatures. No updates this
evening. See previous discussion for additional information.
&&
.AVIATION...Valid through 09/06Z.
Mostly clear. SFC wind less than 12 kts through the period, with
some afternoon gusts around 15 kts at KOLS and KDUG possible
Thursday. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect dry conditions with occasional cirrus clouds
into early next week. Daytime minimum relative humidity values will
generally be in the 15-30 percent range, with slightly higher
humidity values across the higher peaks. 20-foot winds will be
terrain driven at less than 15 mph during much of the period into
next week. However, there will be some afternoon gusty winds at
times. A more easterly component should occur Friday into
Saturday afternoon. Temperatures will cool into next week.
&&
.PREV DISCUSSION...Long period troughiness across much of the U.S.
will bring a slow cooling trend to SE AZ late in the week and into
early next week. Otherwise relatively dry with precipitable water
values near or below 1/2 inch. Surface dewpoints in the 30s this
morning have cratered into the teens and 20s closer to the
international border as northern Sonora and Southeast Arizona see a
low level drying trend over the next 18 hours. The latest HRRR
captures this well. A week westerly flow will bring in some patches
of cirrus level moisture around Thursday or so, but still dry below
that.
Surface high pressure building down the front range of the Rockies
and the Central Plains will bring a lower level southeasterly to
easterly flow late Friday into Saturday. We might see dew points
creep up along with this, but still relatively dry. It will make the
early morning low forecast Saturday morning problematic as we see
some locations with an easterly exposure fail to set up the normal
early morning radiation inversion. With the boundary layer remaining
mixed in those locations overnight temperatures will not drop as
low, even as some nearby sheltered locations do.
Additional energy carving into the back side of the CONUS mean
trough position early in the new week will probably be far enough
west for some gusty winds and more significant cold air advection.
However, any significant moisture and dynamics will likely remain
northeast and east of our area.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Lader/Meyer/Powell
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