Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/09/17
Area Forecast Discussion
National Weather Service Albany NY
1031 PM EDT Sun Oct 8 2017
.SYNOPSIS...
A widespread rainfall will overspread the area overnight with
the rain continuing through Monday as the remnants of Nate move
across the region. The rain will come down heavy at times
Monday, mainly in the morning for areas north and west of the
Capital District. The rain is expected to taper off in the
evening with a fair and warm day Tuesday as higher pressure
builds in.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 1031 PM EDT...Remnant low from TC Nate is located over
eastern Kentucky and continues to move north-northeast along a
stalled frontal zone. This front extends northeast from the Ohio
Valley across our area, with a noticeable change in dewpoints
on either side of the boundary. Areas within the mid-Hudson
Valley continue to see dewpoints near 70, while further north,
dewpoints are in the mid 50s to low 60s.
This front will initially remain stationary across our area
late this evening, but will start to shift northwestward as a
warm front overnight, as the remnant low continues to track
along it and towards the upper Ohio River Valley and eastern
Great Lakes. Although no precip is occurring yet across the
area, mid and high level clouds continues to thicken thanks to
the persistent south-southwest flow at all levels.
Based off the latest 3km HRRR guidance, rainfall (currently
located over central and western PA) will make it into our far
southwestern areas by around Midnight and expand north-
northeastward, reaching the Adirondacks, Lake George area and
southern Vermont by 3 to 4 AM. Rainfall should pick up in
intensity towards daybreak, especially for areas west of the
Capital Region.
Overnight lows will remain mild and muggy (especially for areas
south of the frontal boundary). Lows range from the mid 50s over
the Adirondacks to the upper 60s across the mid-Hudson Valley
and NW CT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
The track of the remnants of Nate have shifted a bit farther to
the north and west and so has the highest expected QPF amounts.
Still looking at a widespread rainfall across the area with the
heavier rain north and west of the Capital District. Total QPF
amounts of 1 to 2 inches with locally higher amount of 3 inches
possible. Remnants move across quickly and with dry antecedent
conditions flooding is not expected on rivers and streams.
However, some ponding of water on roadways should occur with
some flooding of poor drainage and low lying areas possible.
Despite the rain and clouds tempertures will still run 5 to 10
degrees above normal Monday with highs in mid 60s to mid 70s as
the warm front is expected to lift to the north of the forecast
area.
Rain is expected to quickly taper off during the evening hours
with fair weather for Tuesday as the remnants quickly move off
to the east and higher pressure builds in. Conditions warm with
highs in the upper 60s to upper 70s but more comfortable with
dew points in the 50s.
A dampening short wave encountering the ridging across the
region will be on the approach Wednesday resulting in an
increase clouds. Temperatures will be more seasonable but still
above normal by 5 to 10 degrees.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
This will be a mixed scenario of sun and clouds, and showers and
dryness. The period kicks off with near normal temperatures and
rain showers as a trof will lie across the Lower Great Lakes
and northern New York. But high pressure will build quickly down
the appalachian chain, and dryness will ensue for Thursday.
Another weak trof will develop up the mid-Atlantic
coast...bringing a somewhat lesser risk for showers for Friday.
Dryness will return just in time for the weekend, along with a
decent amount of sunshine. As daytime temperatures become
increasingly warmer, highs for Saturday and Sunday will be markedly
above normal, with highs Sunday ranging from around 60 degrees in
the Greens of Vermont, to the lower to mid 70s down the Hudson
Valley. Wednesday night will be coolest, with lows mostly in the
40s. Friday night will be mildest, with low temperatures ranging
from the upper 40s in the higher elevations, to the lower and mid
50s in the bigger valleys and far southern zones.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Flying conditions are currently VFR for all sites, but rain is
rapidly approaching the mid-Atlantic and Ohio Valley regions
thanks to the remnants of TC Nate interacting with a frontal
zone. Rain will arrive after midnight and initially lower
vsby/cigs to MVFR levels for a few hours as it moves in from
south to north. By 06z-10z, IFR conditions will begin from
south to north and continue through the mid morning hours for
both vsbys/cigs thanks to tropical downpours. Behind this
heavier batch, precip will be more showery for the remainder of
the day on Monday, with generally MVFR conditions, for both
vsbys/cigs. There could be a brief improvement back to VFR
around KALB by the late afternoon hours, although this is still
unclear if it will occur or not.
Light to calm winds overnight will become southerly for the
morning hours on Monday around 5-10 kts. Winds look to become
southwest by late in the day Monday at around 10 kts.
Outlook...
Monday Night: Moderate Operational Impact. Chance of SHRA.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Low Operational Impact. Slight Chance of SHRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: Moderate Operational Impact. Chance of SHRA.
&&
.FIRE WEATHER...
A widespread rainfall will overspread the area overnight with
the rain continuing through Monday as the remnants of Nate move
across the region. The rain will come down heavy at times
Monday, mainly in the morning for areas north and west of the
Capital District. The rain is expected to taper off in the
evening with a fair and warm day Tuesday as higher pressure
builds in.
&&
.HYDROLOGY...
A widespread rainfall is on tap for late tonight and Monday
as the remnant Nate approaches and move across the region. Rainfall
of about an inch up to 2 inches is expected at this time with
locally up to 3 inches possible. The rain is expected to come
down heavy at times mainly in the morning for areas north and
west of the Capital District.
Due to antecedent dry conditions and the progressive nature of
the system, flooding is not anticipated on rivers and streams.
However, some ponding of water on roadways should occur with
some flooding of poor drainage and low lying areas possible.
This will be the first widespread rainfall since early September
when moisture from Tropical Cyclone Jose impacted the region.
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.
&&
.CLIMATE...
The record high minimum temperature (warmest low) for October 8th
for Albany is 62 degrees set in 1913. The morning low was only
69 degrees, however we have to see how much the temperature drops
this evening. We should break this.
Records highs were set today at Albany and Glens Falls.
Albany NY: 80 degrees today; old record 79 degrees 2011
Glens Falls NY:80 degrees today; old record 77 degrees 1993
Poughkeepsie NY fell well short with a high of 80 degrees.
The record is 89 degrees set in 2007.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...IAA
NEAR TERM...Frugis
SHORT TERM...IAA
LONG TERM...ELH
AVIATION...Frugis
FIRE WEATHER...IAA
HYDROLOGY...IAA
CLIMATE...WFO ALY
Area Forecast Discussion
National Weather Service La Crosse WI
945 PM CDT Sun Oct 8 2017
.SHORT TERM...(This evening through Monday)
Issued at 222 PM CDT Sun Oct 8 2017
At 1 PM, a weak surface low was located over south-central
Minnesota. The 08.12z models are in good agreement that this low
will move northeast this afternoon and evening. By 1 AM Monday,
it will be located near Green Bay. As this occurs, a Canadian cold
front will move southeast across the region. The HRRR continues to
try and generate a line of showers along this front. However, it
is also showing dew points in the lower 60s and this seems
unrealistic considering the soundings are very dry. As a result,
only expecting some clouds with this front. Besides clouds, there
will be gusty south and southwest winds. The winds will gust into
the 20 to 30 knot range.
On Monday, a longwave trough will advance eastward toward the
Upper Mississippi River Valley from the Northern and Central
Plains. As it approaches, mid and high clouds will move into the
region during the afternoon. High temperatures will range from the
upper 50s to mid 60s.
.LONG TERM...(Monday night through Sunday)
Issued at 222 PM CDT Sun Oct 8 2017
Main forecast concerns in the long term are on chances for showers
Monday night through Wednesday morning. Areas of frost are possible
north Monday night into Tuesday morning. Shower and possibly
thunderstorm chances then return going into next weekend.
A weak shortwave moves in Monday night into early into early Tuesday
morning with showers possible mainly south of Interstate 90. Cool
high pressure quickly builds in early Tuesday morning and we may see
areas of frost across portions of northeast Minnesota through
north central Wisconsin.
Low pressure will track east across southern Iowa through northern
Illinois and eventually into Indiana by late Wednesday morning. This
feature is expected to bring showers to the forecast area. There is
some question as to how far north these showers will get with high
pressure/drier air moving in from the north. At this time it
appears that areas along and south of Interstate 90 will have the
highest chances for seeing rain showers. The Canadian/GFS/ECMWF
are all in line with this idea. However the NAM is indicating a
further south solution. Will have to keep a close eye on the
possibility of the low tracking further south like the NAM
solution. Treated the NAM as an outlier at this point and leaned
toward a model consensus blend for rain chances.
A weak shortwave looks to move across the Upper Mississippi River
Valley Wednesday night into Thursday morning and may bring some
light showers to the region. Confidence is low that this system
will produce any measurable rainfall. Southwest flow aloft then
sets up over the region for late week as a trough deepens over
the western CONUS. A baroclinic zone sets up from central Nebraska
northeast through central Wisconsin Friday through Saturday as
the western conus trough pushes east towards the Great Lakes. Low
pressure looks to develop over southeast Nebraska early on
Saturday, then tracks northeast towards northeast Wisconsin
through the day on Saturday into Saturday night. If the GFS and
ECMWF solutions hold, widespread rain looks like a good
possibility Friday night through Saturday night and possibly into
Sunday, depending on how quickly the low departs.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 945 PM CDT Sun Oct 8 2017
Cigs/WX/Vsby: generally skc vfr conditions into Mon afternoon, with
increasing high/mid level clouds by late monday afternoon/evening
associated with an upper level shortwave trough. Should hold vfr
through Monday night.
Some hints in a few models that a few showers could develop on the
leading edge of the shortwave/associated thin band of low/mid level
frontogenetic lift. Doesn`t look like more then sprinkles/light
showers for Mon evening - with better rain chances to the southwest.
Not enough confidence in development/coverage to add to forecast.
Impact would be minimal.
Winds: will hold from the north/northwest through Monday night.
Expect some gustiness for the afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Boyne
LONG TERM...Wetenkamp
AVIATION...Rieck
Area Forecast Discussion
National Weather Service Binghamton NY
935 PM EDT Sun Oct 8 2017
.SYNOPSIS...
The remains of tropical system Nate, will bring rain to the
region, later tonight and Monday. The weather dries out by
Tuesday, as high pressure noses into the area. Temperatures will
stay well above normal, for the middle of October.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
900 pm update...Rain associated with the remnants of Nate
interacting with a frontal boundary draped from southeast NY to
northeast PA to southwest PA was slowly moving north toward
central NY and northeast PA. The rapid refresh HRRR has backed
off on the onset timing of the showers which matches slower
radar trends. So we have backed off on the onset timing in the
grids by 1-3 hours.
A look at the bigger picture shows that the only lightning so
far detected was well south of PA. But SPC mesoanalysis page
does have some surface based CAPE into eastern PA and NJ where
dewpoints were close to 70F. So we will have isolated
thunderstorms in our northeast PA zones overnight as the rain
spreads north mainly between 03z and 06z as moisture advection
rapidly spreads northward into a favorable dynamical set-up.
Models have a jet entrance region lifting ahead of the surface
low associated with Nate into Quebec by 12z. The right entrance
region will be overhead tonight and lead to low-level
frontogenetic forcing in the presence of strong moisture
advection north of the surface boundary. Hence hi resolution
models all spread showers north quickly.
So other than backing off on initial onset timing of
precipitation, forecast remains essentially unchanged. Chances
for heavy rain seems to be lessening overnight as the main
frontogentic forcing will quickly move north of our CWA by late
tonight. There is concern that heavy bands of rain on the east
side of Nate will affect the region Monday as the southerly
inflow region of Nate reaches into eastern PA/central NY
Monday. There will be a strong low-level jet of around 50 knots
across eastern PA into NY state by Monday afternoon. The 0-1 km
shear was around 45-50 knots and with deep tropical moisture,
low LCL heights, any convective rainbands will not only be
prolific rain producers but also could lead to isolated severe
weather. We could potentially see an isolated tornado or two
given the incredible low-level wind shear if any convective
lines remain intact this far north. This will bear watching for
Monday afternoon.
230 pm update... Model trends, which started with last night`s
runs, of shifting the main axis of heavy rainfall from Nate
farther north and west, have continued today. In fact, there is
now tight model clustering of bringing the remnants of Nate
across western/northern NY Monday, with a SW-NE oriented
frontogenesis forced band of heavy rainfall now mainly north and
west of our forecast area. Although this is certainly a good
trend for our local area, the aforementioned heavier rain band
could still perhaps brush the western Finger Lakes and some of
our far northern areas early Monday. A trailing N-S oriented
band of steadier and perhaps locally heavy rain should push
eastward across southern NY and PA during the morning and midday
hours Monday. Similar rain bands have been seen east and
southeast of Nate today, across GA, eastern TN, and the western
Carolinas.
As a result of what was just mentioned, we still have to be
vigilant for localized training of heavy rainfall, as copious
amounts of moisture will be available. Hopefully, fairly rapid
system movement and dry antecedent conditions will help us out,
but we`ll certainly monitor things closely through Monday.
Often, in the eastern/southern quadrants of a transitioning
tropical cyclone, one has to watch out for low-topped
thunderstorms. Although this has been observed today within some
of the rain bands east and southeast of Nate, the progged
environment Monday over CNY/NEPA should be characterized by very
weak instability and lack of dry air at any level. At this
point, we`ll keep just a mention of isolated thunder.
As alluded to earlier, the overall system is moving quickly,
thus we expect most of the rain to be out of our forecast area
by later Monday afternoon, followed by dry weather Monday night.
Temperatures will stay mild, only falling into the 60s to near
70 tonight, then reaching up into the 70s Monday.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
As the tropical moisture associated with the remnants of Nate
move northeast of our region, the weather will rapidly improve
over NY and PA on Tuesday. mainly a steady rain
A building ridge with very mild 925mb temperatures will push
highs well into 70s by Tuesday afternoon.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Weak waves moving northeastward through the prevailing flow will
keep the weather unsettled over NY and PA through the end of the
work week. A chance for showers exists each day, with the best
chance coming on Wednesday when a diffuse low pressure system
slides out of the Ohio Valley toward Lake Erie.
If the long term models are correct, next Saturday will be a
beautiful mid-October day with plenty of sunshine and
temperatures in the lower-70s.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Tropical moisture associated with Nate`s remnants will move into
our terminals overnight. Rain will reduce visibilities to
between 3/4 and 4SM through Monday morning, with ceilings
falling to 300-900 feet at most locations. IFR to fuel alternate
required ceilings will likely persist through most of the day
with periods of heavy rain in the morning tapering to light rain
after 16-18Z. The light rain should end after 21Z but with low
cigs persisting.
Light winds overnight will increase out of the south at 10 to 15
knots on Monday, with gusts of 20 to 25 knots in the late
morning and afternoon.
Outlook...
Monday night and Tuesday... Most of the rain will be over but
areas of MVFR cigs may persist.
Wednesday through Friday...Primarily VFR but brief restrictions
possible in scattered showers.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...DJN/MLJ
NEAR TERM...DJN/MLJ
SHORT TERM...DJP
LONG TERM...DJP
AVIATION...BJT/DJP
Area Forecast Discussion
National Weather Service Duluth MN
702 PM CDT Sun Oct 8 2017
.UPDATE...
Issued at 653 PM CDT Sun Oct 8 2017
Updated aviation section below for 00Z TAF TAF issuance.
&&
.SHORT TERM...(This evening through Monday)
Issued at 303 PM CDT Sun Oct 8 2017
A cold front will continue shifting east through northwest
Wisconsin this afternoon and evening. There are low chances of
showers ahead of the front late this afternoon and evening, per
the GFS, NAM, SREF, and earlier runs of the HRRR and RAP. The
latest HRRR and RAP are trending drier though.
Otherwise, surface high pressure centered will be building out of
the Rocky Mountains into the Plains overnight and Monday. This
evening looks clear with light wind flow, letting temperatures
drop quickly in this dry airmass. However, models are indicating
mid/high clouds will spread into the Northland later tonight,
giving a little late night insulation. The clearest conditions for
the overall night appear to be in north-central Minnesota, where
temperatures should drop into the lower 30s. A Frost Advisory has
been issued for this area. Patchy frost is in the forecast for
other parts of northern Minnesota. We might need to expand the
Advisory depending on the cloud development later this evening. If
it looks clearer, then we would likely forecast colder
temperatures and expand the Advisory.
Cool air will pour into the Northland Monday. The cold air
advection will mean good low-level mixing, breezy conditions, and
cumulus development. Increased the cloud cover in the forecast,
leaning on the regional Canadian. Highs should range from the
upper 40s to low 50s across northeast Minnesota to the middle 50s
in northwest Wisconsin.
.LONG TERM...(Monday night through Sunday)
Issued at 303 PM CDT Sun Oct 8 2017
The extended forecast period continues to feature a mainly dry
pattern for the upcoming week, with a few cold nights possible,
especially Monday night and Tuesday night.
Monday night and Tuesday morning looks to be very chilly over the
Northland, with sfc high pressure building into the region, along
with mid- to upper-level ridging progged to develop over the
Intermountain West states. Skies look to be mostly clear for this
time frame, especially over the western counties, so the potential
for a hard freeze in some spots will be possible. Lows Monday
night are progged in the middle to upper 20s over north-central
Minnesota, with lower 30s south. Due to the potential for
widespread freezing temperatures, we have issued a Freeze Watch
for all of northeast Minnesota and northwest Wisconsin, effective
Monday evening into Tuesday morning.
Another chilly night is expected for Tuesday night as well.
However, the sfc high pressure should shift to the east, bringing
a light southerly return flow. Temperatures are still expected to
drop to the freezing mark in some spots, but not as cold or as
widespread as Monday night. Lows Tuesday night should range from
near 30 over the International Border/Iron Range regions into the
middle 30s over the south.
No appreciable chances of precipitation expected through the work
week, except for some small chances of showers Wednesday morning
and Thursday morning, mainly over our eastern counties due to weak
850- 700 mb layer warm air and moisture advection. Due to a lack
of deeper moisture, precipitation chances will remain limited.
Given the WAA over the region, Thursday should have the warmest
temperatures of the upcoming work week, with highs in the lower to
middle 60s over the Northland.
The best chances of precipitation won`t arrive until Saturday,
when a more potent shortwave trough rides the northern fringe of
high pressure situated over the southeastern United States. Deeper
lift and moisture will be present with the shortwave. At this
point, the highest chances of precipitation will be Saturday
afternoon. The shortwave energy will linger through the day
Sunday, keeping chances of precipitation over the region.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 653 PM CDT Sun Oct 8 2017
VFR conditions expected through the TAF period. Mid and high
clouds moving into the area from the west is expected to continue
to spread in and expand through 09z, but then thin and shift
south through 18z as cumulus develop. Light west-northwest winds
to increase after 15z and may increase to around 10kts in the
18z-23z time range.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 39 52 31 52 / 0 0 0 0
INL 33 48 26 52 / 0 0 0 0
BRD 39 50 30 52 / 0 0 0 0
HYR 40 56 31 54 / 0 10 0 0
ASX 41 57 33 55 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Freeze Watch from Monday evening through Tuesday morning for
WIZ001>004-006>009.
MN...Freeze Watch from Monday evening through Tuesday morning for
MNZ010>012-018>021-025-026-033>038.
Frost Advisory from 3 AM to 9 AM CDT Monday for MNZ010-011-018.
LS...None.
&&
$$
UPDATE...LE
SHORT TERM...Grochocinski
LONG TERM...JTS
AVIATION...LE
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1148 PM EDT Sun Oct 8 2017
.AVIATION...
Canopy of opaque altocumulus from tropical remnants is in place over
all of southeastern Michigan with MVFR stratus stratocumulus lifting
northward across the Ohio border. Despite high ceilings yet north of
the Detroit area, high based shower activity in most northern band
has been sufficient enough to wet the ground. Plan view progs from
the NAM suggest that near surface moisture will be slow to move in
initially, so continue to keep the TAFS skewed toward the RAP which
prefers stratus over fog. Extremely low midlevel static stability or
even convective instability will exist just above the front at 4.0
to 5.0 kft agl late tonight. Thinking it will take rainfall and a
wet surface to provide near surface moisture for a light ground fog
after 07Z at the Detroit terminals. Did continue with a radiational
fog at MBS late for daybreak given light winds and light northeast
flow contribution off of Saginaw Bay.
//DTW THRESHOLD PROBABILITIES...
* High for cig at or below 5000 FEET tonight.
* low for CIGS/VSBY to fall below 200ft and/or 1/2SM.
&&
.PREV DISCUSSION...
Issued at 309 PM EDT Sun Oct 8 2017
DISCUSSION...
Sunny and warm conditions will again change rapidly this evening
with increasing clouds from the south from the remnants of Nate.
Impressive strong and deep deformation and Fgen across the Ohio
River valley will lift north as Nate moves into the Upper Ohio River
Valley tonight. These forcing features weaken as they move northward
into the southern Lakes region by 03z-06z. There is also some upper
divergence from the right entrance region of a jet streak that
situates itself over the Great Lakes. Plenty of moisture moving
north as well with Nate. All of this leads to more confidence in
the models that indicate rain for the southeast half of the forecast
area. Interesting to note that the GFS and NAM have switched with
the GFS now the wetter solution, but given the consistency of the
ECMWF and Canadian, will lean toward those depictions of POPs.
Gradient of POPs will be over the forecast area with categorical for
Monroe county, likely for much of metro Detroit and just chance
north of that up to a Port Sanilac to Howell line.
Other issue overnight is the chances of fog. Given a couple bouts of
up to half inch of rain in the last few days, dew points in the 50s,
light easterly component from the warmer Great Lakes and the longer
nights of October, think areas of fog will develop where there will
be a decent amount of clear skies overnight. Will go with areas of
fog mainly north and west of that Port Sanilac to Howell line and
just patchy fog south of there.
Nate pulls away early Monday, leaving a few hours of morning clouds
for the southeast half of the forecast area and chance POPs for just
the far southeast corner. By noon all of southeast Lower MI will
have sunny skies which allow temperatures to warm well above average
in the mid and upper 70s again.
A weak cold front drops down from the northwest later Monday night
and into Tuesday. Forcing is very weak and moisture quality is
lacking. Expect more clouds and cooler temps with a more pronounced
northerly flow on Tuesday, but will leave out any chance of a shower
to develop around the front. The next upper low moves toward the
southern Great Lakes late Tuesday night and Wednesday. Trend is for
a slightly slower and more southern track, but still expect
widespread rain for the bulk of the forecast area.
An advancing upper-level ridge and surface high pressure will move
into the Midwest and eastern U.S. late Wednesday and will remain in
place through the remainder of the week, providing minimal
opportunities for rain showers or thunderstorms. As the ridge
continues to advance east, wind direction will shift from the
northeast to the southwest, allowing daytime high temperatures to
return back into the upper 60s to lower 70s by the afternoon. For
reference, normal daytime high temperatures reside in the lower 60s
across SE Michigan for mid-October.
A surface low is then expected to develop across the Plains later
this week and push into Wisconsin to northern lower Michigan
Saturday into Sunday, which will allow a strong surge of warm air to
push across the state, as noted in the 850mb thermal layer, where
temperatures averaging 7 - 9 degrees C by late Thursday peak between
16 - 18 C late Saturday. This will allow temperatures to peak in the
mid-70s for a daytime high but will also bring the chance for
showers and thunderstorms, mainly across the Tri-Cities to Thumb
region as a baroclinic zones lines up across Central Michigan.
Better rain and thunderstorm chances move in for all of SE Michigan
through Sunday as the low moves through Ontario, allowing a cold
front to swing through state throughout the day.
MARINE...
Quieter conditions across the eastern lakes through Monday as high
pressure builds across the region. Winds continue to decrease today
as do wave heights, resulting in minimal marine concerns. The
remnants of Hurricane Nate will lift north today with the northern
edge of the precipitation shield clipping the Eastern Lakes, with
light showers possibly spreading from Lake Erie up into Southern
Lake Huron tonight for a few hours. Winds will be light as they back
from south to north through the overnight hours. A cold front will
drop through the region late Monday which will bring about northwest
flow and winds gusting to around 25 knots.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....CB
DISCUSSION...RBP/AM
MARINE.......DRK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Green Bay WI
607 PM CDT Sun Oct 8 2017
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Monday
Issued at 257 PM CDT Sun Oct 8 2017
The latest RAP analysis and satellite/radar imagery show a cold
front moving into northwest Wisconsin early this afternoon. A
very dry airmass ahead of the front based on 12z MSP and INL
soundings have limited any shower activity to far northern
Minnesota so far today. However, most of the hi-res model guidance
show a narrow line of showers developing during the 22-00z time
period over north-central WI and the western Upper Peninsula.
Because of this strong general consensus, will keep these showers
in the forecast despite precip pulling out of the arrowhead of
Minnesota early this afternoon. Besides light precip chances,
cloud trends are also one of the main forecast concerns.
Tonight...The moisture starved cold front will sag southeast
across the area from early evening through early overnight. Hi-res
models continue to indicate that the saturated layer along the
front will be the most robust over north-central WI this evening,
and looks deep enough for light showers or sprinkles. The moisture
dries up as it moves into eastern WI, though could see some broken
clouds arrive late. With northerly winds picking up behind the
front, conditions do not look to support fog, despite some hints
from the sref and statistical guidance. Lows ranging from the low
40s in the north to mid 50s near the Lake.
Monday...If clouds materialize as guidance indicates, sct to
broken clouds could linger over eastern WI through early to mid
afternoon. Otherwise, skies should range from mostly sunny to
partly sunny. Temps will be cooler than todays readings, and range
from near 60 in the north to the mid 60s south.
.LONG TERM...Monday Night Through Sunday
Issued at 257 PM CDT Sun Oct 8 2017
The main forecast concerns will be frost potential across
northern WI Monday night and Tuesday night, then precipitation
chances for the middle of the week and especially next weekend.
High pressure will build into the northern Great Lakes Monday
night, and linger over the region through Tuesday night. There is
some potential for a frost/freeze event over northern WI both
nights. There are concerns about whether or not clouds will
decrease early enough on Monday night, and increase earlier than
thought on Tuesday night, to allow for widespread frost events.
However, confidence is high enough to lower temperatures a few
more degrees in the typical cold spots and keep frost in the
forecast/grids. Overall, these should be low impact events, as
there have already been a number of frost (and localized freeze)
events in northern WI, and the growing season is basically over
there.
An upper level trof and associated surface low will impact the
region Tuesday night into Wednesday. The ECMWF continues to be
more aggressive than other models, but no longer brings rain as
far north as it was showing in earlier runs. Current indications
are that northern WI will remain dry, with light to moderate rain
developing farther south. Have bumped pops to likely in our
southern tier of counties Tuesday night.
Expect a quiet period of weather for the end of the work week,
with above normal temperatures. Some light showers will develop
late Friday and Friday night as a cold front moves through the
region.
A fairly potent frontal system is expected Saturday into Saturday
night, as a surface wave lifts northeast along the lingering
frontal boundary. Dynamics look fairly impressive with this
system, with an 850 mb warm front and associated strong low-level
jet lifting into the region, and the RRQ of a 150 knot jet
providing upper support. Weak elevated instability will be in
place Saturday and Saturday night, so kept a mention of thunder
in the forecast for those periods. In addition, PWATs increase to
1.5 to 1.8 inches over the southeast half of the forecast area,
so there is potential for heavy rainfall, especially Saturday
afternoon and evening.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 606 PM CDT Sun Oct 8 2017
A cold front will slide over the state tonight.
Mainly VFR mid levels were associated with the cold front passage
early this evening. Patchy MVFR clouds may develop Monday behind
the front and in the cooler air mass cooler air working into the
region.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kieckbusch
AVIATION.......TDH
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
628 PM CDT Sun Oct 8 2017
.SYNOPSIS...
Issued at 357 PM CDT Sun Oct 8 2017
H5 analysis this morning had a fairly low amplitude pattern
across the CONUS. Two main features of note are a shortwave trough
over the mid atlantic and a deepening trough of low pressure over
the intermountain west. A third shortwave was noted over northern
Manitoba. With respect to the western CONUS shortwave: Ht falls
in association with this feature were running from 100 to 150
meters across southern Idaho, western Wyoming and northern Utah
this morning. Further deepening of this feature is expected over
the next 12 to 24 hours, as it is being fed by a 50 to 70 KT jet
streak which is currently oriented from western British Columbia
into western Oregon. Mid level cloud cover and precipitation in
advance of the western CONUS feature was noted from swrn Wyoming
into far western South Dakota this afternoon. This area of
cloudiness was drifting slowly south and was approaching the
northern Nebraska Panhandle as of mid afternoon. At the surface:
Low pressure was located over southern Minnesota with a cold front
extending ssw into sern Nebraska and swrn Kansas. North of this
feature, winds were from the north or northeast and were gusting
into the 20 to 25 MPH range across portions of central and
southwestern Nebraska. Temperatures as of 3 PM CDT were in the mid
50s in the northwest, to the mid 60s south of Interstate 80.
&&
.SHORT TERM...(This evening through Monday)
Issued at 357 PM CDT Sun Oct 8 2017
Main forecast challenge through Monday afternoon deals with a potent
mid level shortwave crossing the Rockies/Northern Plains and low
that closes off over Kansas. Specifically, p-type will be tricky due
to temps.
Clouds will continue to thicken from northwest to southeast across
the area as easterly H7-8 flow contributes to upslope flow ahead of
the shortwave. Model consensus has slowed the start of the precip
slightly, which agrees with current satellite and sfc ob trends. The
best moisture aloft remains over central WY/far western SD per WV
and IR imagery, and sfc dew point depressions around 25F remain at
KAIA and KGRN as of 20z. Slowly work PoP in to cover areas west of
Hwy 83 by 03z and Hwy 183 by 06z. Kept all precip as -RA through
05z, then begin to add RASN across the far NW. Initially used sfc
temps of <37F to determine RASN and <34F for SN, then tweaked using
forecast soundings. The NAM is the coolest model, suggesting a
subfreezing layer as low as H85 and sfc wet bulb around 2C at KAIA,
KCDR, and Merriman. RAP and GFS showing slightly warmer temp
profiles, which will make a large difference in this scenario due to
being near freezing. Brought RASN line east to Hwy 61 and north of
Hwy 92, and all SN primarily invof the Pine Ridge. Went conservative
on the snow amounts due to the amount of rain mixing in and warm sfc
temps (4" soil readings in the 50s). Stayed near guidance for
overnight lows with increasing cloud cover and precip, but trended
toward the cooler solutions for Monday highs.
The main concern of expanded area of RASN or SN is reliant on the
magnitude of dynamic cooling. RAP and NAM agree with a couple
deformation bands developing across the forecast area - one
NW/panhandle and one central Sandhills to SW Neb. Cross section
analysis suggests some slantwise instability, which could lead to
enhanced precip rates and increased cooling in the temp profile.
Can`t rule out mixed precip as far east as KOGA to KVTN with the
deformation band setting up in the pre-dawn hours. Even if a
complete switch to snow occurs, little accumulation is expected.
Stronger lift occurs H5-7, but the DGZ lies primarily H4-6.
Regardless, SLRs are low, i.e. <10.
.LONG TERM...(Monday night through Sunday)
Issued at 357 PM CDT Sun Oct 8 2017
Monday night through Wednesday: The main forecast challenge deals
with precipitation chances in the east with the exiting h5 trough
Monday night, along with low temperatures Tuesday morning and the
threat for widespread freezing conditions. For Monday Night with
respect to the timing of the exiting h5 system and precipitation
chances: The latest NAM12 soln has slowed somewhat, allowing
deformation precipitation to back into sern portions of the
forecast area Monday evening. The GFS is more progressive and
leads to a dry fcst for the sern CWA Monday evening. With the
NAM12 and the gfs to a lesser degree, indicating some lingering
cloud cover in the sern forecast are late Monday night, will hold
onto a freeze watch for Frontier, Custer, Garfield and Wheeler
counties. Elsewhere, feel we will be clear enough overnight to
reach the mid to upper 20s and will upgrade the freeze and hard
freeze watches to warnings. Utilized a blend of the MET and MAV
guidance temps for lows Monday night, which was below the
superblend. On Tuesday, we should see clear skies across most of
the forecast area but highs will remain cool with readings in the
50s. Warmer air will push into the region for Wednesday, thanks to
the development of a low amplitude ridge across the high plains
downstream of a deepening trough across the Pacific Northwest.
Highs Wednesday will reach the mid to upper 60s.
Wednesday night through Sunday: Dry conditions will continue through
Friday with highs Thursday in the 70s. An upper level wave will
cross southern Canada Thursday Night, forcing a cold front into
western and north central Nebraska. ATTM, forcing for post frontal
pcpn will remain north of the forecast area, so a dry forecast
continues. Highs Friday will be upper 50s to lower 60s. A second
upper level trough of low pressure will deepen across the
intermountain west Saturday, inducing surface cyclogenesis across
eastern Colorado. This will lift the front north as a warm front
Friday night into Saturday with an increasing threat for showers,
mainly in the eastern forecast area Saturday. A better chance for
showers will arrive Saturday night into Sunday as the trough of low
pressure aloft traverses the Central Plains.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 628 PM CDT Sun Oct 8 2017
Indications from the SREF suggest IFR/LIFR in SN/RA and low
cigs/vsby will generally remain along and west of highway 61
tonight and Monday. MVFR/VFR will occur east of highway 61.
VFR will become widspread along and north of I-80 by 00z Monday
evening.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Hard Freeze Warning from midnight CDT /11 PM MDT/ Monday night
to 10 AM CDT /9 AM MDT/ Tuesday for NEZ004>006-008-009-022>027-
035>037-056>059-069-094.
Freeze Warning from midnight Monday night to 10 AM CDT Tuesday
for NEZ007-010-070.
Freeze Watch from late Monday night through Tuesday morning for
NEZ028-029-038-071.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Snively
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
738 PM EDT Sun Oct 8 2017
.SHORT TERM...(This evening through Monday)
Issued at 402 PM EDT SUN OCT 8 2017
WV imagery and RAP analysis indicated a mid/upper level trough
over the ern CONUS and a trough from nrn Manitoba into the Rockies
resulting in sw flow through the plains and nrn Great Lakes. At
the surface, a cold front extended from just west of James Bay
through wrn Lake Superior. Clouds and light pcpn with fgen behind
the front were lifting ne of the MN arrowhead.
Tonight, increasing 850-700 mb fgen forcing along and in the wake of
the front and associated upper level with the right entrance region
of 140 knot 250-300 mb jet max over nrn Ontario will support an
increase in clouds and potential for isold/sct -shra over mainly the
northwest half of cwa this evening. With dry low levels and little
moisture inflow, mainly sprinkles or only a few hundredths of an
inch are expected. Expect decreasing clouds behind the front later
tonight as min temps drop as low as upper 30s interior west and into
upper 40s/lower 50s east half of the cwa.
Monday, high pressure building into the area with anticyclonic nrly
flow will bring mostly sunny skies and high temps into the upper 50s
west and lower 60s southeast.
.LONG TERM...(Monday night through Sunday)
Issued at 328 PM EDT SUN OCT 8 2017
Overall, we`re looking at quiet weather and seasonable temperatures
through the first half of the week. Above normal temperatures will
return towards the end of the week ahead of an approaching cold
front. Confidence is increasing that we will see another system
track across the region bringing dreary and breezy conditions next
weekend. Heavy rain look possible with this system; however, the
exact location within the region that will see this heavy rain is
hard to pinpoint at this time.
A potent shortwave will track across the Middle Mississippi Valley
and eventually across the Lower Great Lakes region as it weakens
Tuesday night into Wednesday. The majority of the precipitation
associated with this system is expected to remain south of Upper
Michigan, but cannot rule out a few showers making into the far
south central. Otherwise, dry weather and seasonable temperatures
are expected to prevail as surface ridging tracks across the Upper
Great Lakes Monday night through Wednesday.
Thursday and Friday, surface ridging will slide east of the area in
response to return flow developing across the Plains as shortwave
energy embedded within longwave troughing across the western CONUS
ejects out across the northern Plains. We will see temperatures warm
5 to 10 degrees above normal in response to this return flow.
Precipitation wise, the main forcing is expected to remain north of
the area; however, a weak cold front will push east across the area,
which may bring a few scattered showers. The best chance for these
scattered showers will be Friday and Friday night once stronger warm
air advection arrives, along with enhanced jet dynamics.
Saturday morning there could be a few lingering showers, mainly
across the east; however, much of the area is expected to remain dry
during the first half of the day on Saturday as the above mentioned
cold front stalls out just south of Upper Michigan. Saturday
afternoon/evening through Sunday this baroclinic zone will become
reinforced and lift back north as the main longwave trough out west
lifts across the central Plains, and eventually up across the Upper
Great Lakes. This will result in the return of cooler, rainy and
windy conditions. As mentioned above, it is difficult to pinpoint
this far out what locations across the region will see the heaviest
rainfall; however, based on current model guidance the heaviest rain
looks like it may set up across southern portions of Upper Michigan
or just south of of the area into Wisconsin and lower Michigan.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 737 PM EDT SUN OCT 8 2017
VFR conditions will continue through the forecast period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 402 PM EDT SUN OCT 8 2017
Winds should be mostly less than 20kt tonight through Friday as high
pressure generally dominates through the period.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Ritzman
AVIATION...07
MARINE...JLB
Area Forecast Discussion
National Weather Service Mount Holly NJ
1151 PM EDT Sun Oct 8 2017
.SYNOPSIS...
A cold front will become stationary just north of our region, then
move slowly north overnight. Meanwhile, the remnants of Nate will
traverse the Appalachians, moving just west of our area on Monday.
Another cold front frontal passage is expected Tuesday night. A
sprawling area of Canadian high pressure will settle across our
region Wednesday through early next weekend. An additional cold
front may approach our area by late next weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Showers will develop and become more widespread as we head into
the early morning hours across eastern Pennsylvania and
northern New Jersey with the remnants of Nate moving north. Both
the HRRR and RAP models ramp this activity upward for a few
hours followed by another lull toward sunrise. POP grids were
adjusted to take into account convection trends and the new
mesoscale model data.
Lows will bottom out in the upper 60s to lower 70s. The
exception will be the higher terrain where mid 60s are expected.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
Overall rainfall totals have come down a bit across the coastal
plain. General totals are now expected to be in the 0.50 to 3.00
inch range across the CWA with the highest values across the western
zones. We can`t rule out some higher isolated amounts as some
convection is possible in the late morning through mid-afternoon
period as the last remaining piece of Nate moves through. SPC isn`t
all that excited about severe convection tomorrow as instability is
almost non-exist. But it`s hard to ignore that amount of shear that
will be crossing over the region.
As for precipitation, there will be a break for many of us in the
morning hours after daybreak. More showers (and maybe thunder) can
be expected in the later morning hours into the mid-afternoon hours,
from west to east. Models have sped up Nate. Any precipitation looks
like it will be done by the evening hours.
Winds in general will be in the 15 to 25 mph range. However, gusts
up to 45 mph are possible in and near stronger convection as winds
aloft are mixed down.
Temperatures are expected to remain above normal, and top out about
10 degrees above normal once again.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
The mid level progs continue to feature a period of southwest to
west flow aloft through the duration of the forecast period. Within
this flow, brief shortwave ridging is expected in the wake of Post
Tropical Cyclone Nate on Tuesday. The next shortwave impulse will
traverse invof the NY/PA border Wednesday into Thursday. A higher
amplitude shortwave will approach our region late next weekend.
During the interim, there are several smaller perturbations in the
somewhat zonal flow traversing our region.
The main forecast challenges continue to be Tuesday`s high temps, as
well as temporal and spatial uncertainty in precip Wednesday through
Friday.
Tuesday...The trend is for the cold front to time through our region
earlier, therefore, PoPs have been updated accordingly. We maintain
a slight chance across southeast NJ and southern Delmarva during the
day. Elsewhere...dry. Skies will become mostly sunny north of the
aforementioned area. While a drier airmass will gradually filter
south across the area, it will remain warm for October, with model
soundings indicating 850 hPa temps of around 17C east of the I-95
corridor. Model guidance has also been biased cold, up to 5 degrees
recently with maximum temperatures. The 12Z/08 MAV and EC 2-meter
temperatures are warmer compared to the MET, yet still seem too
conservative. With this forecast, we have bumped high temps up on
Tuesday where we expect full sun, and played it more conservative
under the cloud cover. Record highs may be in jeopardy at ACY and
GED, but overcast skies may hold temperatures below these levels
(see the climate section). Also, given clearing skies and the recent
rainfall, winds may decouple enough for some patchy fog Tuesday
morning, mainly in the more prone locations northwest of I-95.
Wednesday through Friday...We have the most confidence in precip
during the Wed-Thu time frame as a shortwave to the north skirts by,
so the forecast reflects continued chance PoPs. This timing is about
12-18 hours later compared to yesterday`s forecast package. Going
into Thu night and Friday, less confidence. Despite a strong ridge
at the surface, deterministic models continue to generate light
precip, while the ensembles remain drier. This forecast continues to
favor the drier solution, with slight chance PoPs across the area.
This period will feature high temperatures at or below normal, while
considerable cloud cover will keep low temps generally above normal.
Saturday and Sunday...Increasing southwest flow leads to the return
of above normal temperatures. There is uncertainty regarding how far
east the Great Lakes cold front advances on Sunday. For now, we kept
the forecast dry for both days.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Tonight...VFR conditions will carry through a good portion of the
evening hours. Ceilings everywhere are expected to drop into
the MVFR range, and most likely through it, by daybreak.
Precipitation should spread in across most/all the terminals
after midnight.
Monday...Terminals will start the day off with MVFR/IFR. The
precipitation is expected to take a break in the morning hours for
most of the terminals before spreading back into the picture late
morning and afternoon. A low level jet will be developing.
Directional shear won`t be present, but a fair amount of speed shear
will.
Outlook...
Mon night...MVFR due to low ceilings possible at ACY and MIV. In
addition, cannot rule out brief MVFR in fog at ABE and RDG. VFR
otherwise.
Tue through Wed...Predominantly VFR.
Wed night through Fri...MVFR possible in low clouds all terminals,
mainly Wed night and Thu night, with a return to VFR during the day
time.
&&
.MARINE...
Tonight...winds and seas are expected to remain below SCA
conditions.
Monday...SCA conditions are expected to develop once again around
daybreak and continue throughout the day. If convection develops in
the afternoon, gale force gusts will be possible and will be
covered short-fused SMWs.
Outlook...
Northwest winds will likely remain at SCA levels into early Monday
night, with seas subsiding below SCA levels Tuesday morning. Thus,
the SCA may be needed into Tue morning.
Easterly winds may reach SCA levels again Wed afternoon, and this
could linger into Thursday afternoon. While winds may subside by
this point, the continued east flow (long fetch) may result in
elevated seas into Friday.
&&
.TIDES/COASTAL FLOODING...
A few sites in southern New Jersey and Delaware could approach minor
flooding thresholds with the high tide cycle again Monday morning
(between 10:30 AM EDT and Noontime on the oceanfront). However, all
guidance continues to indicate that we shouldn`t see widespread
minor tidal flooding. Thus, we are not planning on issuing a coastal
flood advisory at this time.
Along the eastern short of MD, despite the southerly flow, we expect
to remain below minor flooding thresholds for Monday evening`s high
tide.
&&
.CLIMATE...
There is the potential for daily record high temps on Tuesday,
October 10th. For your convenience, records are listed below.
At this time, only ACY, GED, ILG, and PHL are forecast to be
within 5 degrees of their respective daily record high temp.
Site Record Year
____ ______ ____
ACY 85 1939
PHL 90 1939
ILG 89 1939
ABE 89 1949
TTN 89 1939
GED 86 1958
RDG 89 1949
MPO 86 1949
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 7 AM Monday to 8 AM EDT Tuesday for
ANZ450>455-470>473-475.
&&
$$
Synopsis...Franck
Near Term...Gaines/Kruzdlo/Miketta
Short Term...Kruzdlo
Long Term...Franck
Aviation...Franck/Kruzdlo/Miketta
Marine...Franck/Kruzdlo/Miketta
Tides/Coastal Flooding...
Climate...
Area Forecast Discussion
National Weather Service Blacksburg VA
1048 PM EDT Sun Oct 8 2017
.SYNOPSIS...
Tropical Depression Nate will progress into the Ohio Valley
overnight. The remnants of Nate will continue heading northeast
through West Virginia and Pennsylvania early Monday with a cold
front following in its wake across our region Monday afternoon.
This front will briefly stall to our south, but then progress
north again as a warm front starting Tuesday.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 1040 PM EDT Sunday...
Area of moderate to heavy rainfall continues to spread northeast
across NW NC into SW Va late this evening. Have had reports of
2-4 inches of rain per automated gages, as well as reports via
social media of flooding in the Boone area. Streams and creeks
are reacting to this tropical rainfall, despite how dry we have
been.
Will continue with the flash flood watch overnight, but think we
can cancel it before dawn as back edge of heavier rain shield is
already moving toward northeast TN, while TD Nate weakens over
the Cumberland Plateau.
Synoptic models appear too slow with shield of rain and low,
while the HRRR looks to start weakening the showers over the
mountains by 10z/6am, as does the RAP13. With the next update
will likely see lower pops past 8am Monday in the west.
Previous early evening discussion...
Rain becoming more widespread over the NC mountains/foothills
northwest into SW VA early this evening. Had one tornadic cell
cross from Caldwell into Wilkes County, but so far no confirmed
tornadoes in Wilkes, but some damage reported.
As far as Nate and the rain goes, appears models on track to
give the southwest CWA about 2-3 inches of rain through dawn
with locally higher amounts, with lighter amounts further east.
Current flash flood watch and wind advisory cover the scenario
well and no changes planned. Will be monitoring streams and
rainfall rates for any possible flood/flash flood advisories or
warnings. Severe threat is starting to diminish but some showers
could bring down stronger winds this evening over NW NC.
Previous discussion from mid afternoon...
Have expanded the Flash flood Watch into Tazewell county. RFC
forecast for the North Fork of the Holston River had the site
going to action stage tomorrow evening. Expecting enough
rainfall tonight that smaller streams have an enhanced threat of
flooding across the watch area.
Have expanded the Wind Advisory for tonight. Through 03Z/11PM
surface through 850mb winds are out of the southeast and
downsloping will enhance winds in areas like Tazewell and Mercer
counties. For much of the period from 22Z/6PM through 12Z/8AM
3KM NAM was showing the potential for strong winds at higher
elevations in southwest Virginia and northwest North Carolina,
especially along the southern Blue Ridge. 850MB winds may be as
high as 65 knots. So Advisory now covers into Mercer County WV
and along the Blue Ridge through Floyd and Patrick Counties.
Radar showed a well defined band of showers and thunderstorms
associated with Tropical Depression Nate from eastern Tennessee
into northern Florida. Models show good consensus bringing the
leading edge of this band into Watauga County around 22Z/6PM and
progressing the tropical precipitation southwest to northeast
across the region by 15Z/10AM Monday. Much of any heavier
precipitation will fall in the 00Z/8PM to 12Z/8AM time frame. By
Monday morning winds turn to the west and the remnants of Nate
will be well to the north. West winds will favor diminishing
precipitation and cloud east of the Blue Ridge Monday afternoon.
Guidance was forecasting steady or rising temperatures
overnight. Challenging to agree with rising nightime
temperatures in October but agree there will be no change in air
mass. Will use a non-diurnal trend for hourly temperatures
tonight.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 230 PM EDT Sunday...
Remnants of Nate will move off the New England shore Monday
night. In the wake of Nate, a baroclinic zone will lay over the
Carolinas Monday night, then lifts north over the area on
Tuesday. Models are displaying a weak surface ridge developing
over southern Virginia Tuesday night. Even though this surface
ridge looks like a weak insitu wedge with easterly flow and
diabatic cooling, it does not have a true parent center.
Regardless of this feature`s classification, weak isentropic
lift over a high PWAT/theta-E environment will bring either
light rain, drizzle, low clouds and/or fog to the area,
especially along and east of the Blue Ridge. Damp and dreary
conditions remain over the area into late Wednesday morning. By
Wednesday afternoon, pressure falls over the Ohio Valley may
help this surface feature dissipate over the area to see some
sun. Rain chances decrease, but fog and/or low stratus cloud
deck likely to return Wednesday night.
Temperatures will be cooler than what we have been seeing, but
still running warmer than normal. Highs each afternoon will
primarily be in the 70s. Overnight lows will be generally in the
60s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 230 PM EDT Sunday...
The upper level ridge that has been along the southeast coast
over the weekend will retrograde westward along the Gulf States
during the work week. The center of this ridge may actual move
over eastern Texas by Friday. This ridge will expand from the
Gulf states and cover the Tennessee Valley and the southern
Appalachains Mountains by next weekend.
To start the period, Thursday afternoon temperatures will be
close to seasonal with most locations in the low 70s. Afternoon
temperatures will warm a few degrees each day. By Sunday,
temperatures will range from the upper 70s to lower 80s. There
will be chances for showers each afternoon, but areal coverage
and duration will be limited to cover with a PoP less than 20
percent.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
As of 720 PM EDT Sunday...
Not a good night to fly with rain expected to overspread much of
the area with strong winds associated with TD Nate. Cigs will
drop to MVFR to IFR as will vsbys with moderate to heavy
showers. Non-convective LLWS possible but with rain showers,
wind shear will already be there through overnight.
Should start to see some diminishing rainfall intensity Monday
morning, with models starting to improve conditions in the
afternoon back to MVFR to VFR with rainfall ending.
Extended Aviation Discussion...
A weak front will stall across VA/NC on Tuesday. This boundary
will bring the chance for sub VFR ceilings and showers for a
line south of KBLF, KROA and KLYH Tuesday and Tuesday night. A
wave tracking along this boundary will likely bring rain to the
region for Wednesday. High pressure and drier weather return on
Thursday and Friday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Wind Advisory until noon EDT Monday for VAZ007-009-010-012-
015>017-032.
Flash Flood Watch until 8 AM EDT Monday for VAZ007-009-015.
NC...Wind Advisory until noon EDT Monday for NCZ001>003-018-019.
Flash Flood Watch until 8 AM EDT Monday for NCZ001-002-018.
WV...Wind Advisory until noon EDT Monday for WVZ042.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...AMS/DS/WP
Area Forecast Discussion
National Weather Service Seattle WA
836 PM PDT Sun Oct 8 2017
.SYNOPSIS...An upper ridge will move over the area tonight and
Monday for dry weather and mostly clear skies. A series of upper
troughs will bring cool weather, some showers, and occasional sun
breaks Tuesday through Saturday.
&&
.SHORT TERM...An upper ridge will cross the area tonight and
Monday for dry weather. Areas of fog are likely later tonight and
Monday morning with mostly clear skies, light winds, and lingering
low level moisture from recent rains. It will be a bit chilly
tonight with lows dipping into the upper 30s in the colder spots.
Northerly flow aloft will back to westerly Monday ahead of a weak
approaching frontal system. High clouds will probably increase
ahead of this front during the day. The front and an upper trough
will push into the area Tuesday for a chance of showers. A Puget
Sound Convergence Zone is likely behind the front Tuesday night.
The upper trough will remain over the area Wednesday for a
continued shower threat.
The mountains could pick up a few inches of snow Tuesday night and
Wednesday as snow levels around 5500 feet Tuesday lower to 3000
to 3500 feet by Wednesday morning. There will be a corresponding
cooling of daytime highs over the next few days going from lower
60s Monday to lower to mid 50s by Wednesday. Schneider
.LONG TERM...Previous discussion...Although the trough axis
pushes eastward of the area come Thursday...W WA will find itself
still in a troughy pattern. GFS solutions have shown some variance
here in the past 24 hours...as earlier solutions shifted any
associated precip more to the south of the area...whereas current
solution plows the moisture...and thus precip...directly into the
area. The ECMWF...as is becoming a theme in this
discussion...maintains a wetter solution. While this may be an
indication of the GFS adopting or at least transitioning toward a
solution more akin to the ECMWF...the fact that this breaks from
previous solutions cannot be overlooked and as such...have
continued the forecast trend of finding a middle ground between
the drier past GFS solution and the consistent wet ECMWF. Should
the next GFS run continue this wet trend...however...would not be
surprise to see POPs for this period trend upward.
This trough and its associated moisture looks to linger on into
Friday before a very weak ridge provides a breather late Friday
night and into Saturday morning. From there...it looks like another
trough is on the way to allow for a wet weekend. SMR
&&
.AVIATION...A transient upper ridge axis will pass across Western
Washington early Monday morning, then an upper trough will start
to move southeast down the B.C. coast on Monday night. Moderate
northerly flow aloft tonight will become westerly on Monday
afternoon, then southwesterly on Monday night. The air mass will
be dry and stable, though high clouds AOA 150 will thicken quite a
bit on Monday. Otherwise, expecting fog-prone locations such as
river valleys to get socked in late tonight, followed by rapid
late morning burnoff.
KSEA...Other than some cirrus, clear night ahead. Expecting fog to
form in the valleys to the east-southeast of the airport late
tonight and Monday morning. Should mostly avoid the airfield. The
latest LAMP guidance and HRRR models show no fog at KSEA in the
morning. Still, there is the possibility of light east wind
slopping a little fog up the hill and over the airfield for a
short time (1 hr or less) as the fog starts to break up 1-2 hours
after sunrise, or around 8-9 am. Latest TAF amendment trended
more optimistic with prevailing conditions in the morning while
narrowing the TEMPO group for cig/vsby restrictions into a smaller
time window in that post-sunrise period. Haner
&&
.MARINE...West-northwest swell over the coastal waters is in the
process of subsiding. Buoy 87 now shows swell under 10 feet, so
will end the SCA at the West Entrance. Elsewhere, swell will
subside below 10 feet later tonight.
Meanwhile, light northerly flow will develop tonight due to
rising pressure over British Columbia with lower pressure over
Oregon. Expect the flow to become nearly flat on Monday. A cold
front will arrive from the northwest early Tuesday morning, with
onshore flow following the front during the day. The flow will
become more northerly on Wednesday. Haner
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory for hazardous seas until 3 AM PDT Monday
for Coastal Waters From Cape Flattery To James Island 10 To
60 Nm-Coastal Waters From James Island To Point Grenville
10 To 60 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater 10 To 60 Nm.
Small Craft Advisory for rough bar until 11 PM PDT this evening
for Grays Harbor Bar.
Small Craft Advisory for hazardous seas until 11 PM PDT this
evening for Coastal Waters From Cape Flattery To James
Island Out 10 Nm-Coastal Waters From James Island To Point
Grenville Out 10 Nm-Coastal Waters From Point Grenville To
Cape Shoalwater Out 10 Nm.
&&
$$
www.weather.gov/seattle
You can see an illustrated version of this discussion at
www.wrh.noaa.gov/sew/gafd/latest_webafd.html
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
530 PM MDT Sun Oct 8 2017
.DISCUSSION...(This Evening Through Sunday)
Issued at 238 PM MDT Sun Oct 8 2017
The latest water vapor images and RAP analysis had a positively
tilted upper trough over the northwestern CONUS with at least a
110 kt jet from KSLC to KINL. Banded rain/snow extended from
southwestern WY into north-central SD, with some snow
accumulating over the highest Black Hills. This was being forced
by the jet along with midlevel frontogenesis.
For tonight the best Q-G forcing will shift to the south of the CWA
as does the frontogenesis and isentropic lift. This will allow for
the band of precip to gradually move across southwestern SD. The
latest radar trends show a contraction of the band with convective
type elements along the southern edge of the band; thus, may see
some locally heavier rain/snow amounts than what has been suggested
by the models.
The upper low will move to our south on Monday with drier air
filtering into the area, and precip coming to an end over southern
SD during the morning. Clear skies, light winds, and 850-mb temps of
0-3C will then set the stage for frost over south-central SD late
Monday night and Tuesday morning.
Otherwise, dry and warmer weather is expected later Tuesday into
Friday as a flat ridge dominates much of the central/eastern CONUS.
Another trough will move over the area next weekend, bringing
another round of rain/snow.
&&
.AVIATION...(For the 00Z TAFS Through 00Z Monday Evening)
Issued At 528 PM MDT Sun Oct 8 2017
Bands of -RASN over northeast WY/southern SD with MVFR conditions
will slip slowly southward this evening, leaving the area by
morning. Local IFR conditions expected near the higher terrain of
the Black Hills. Conditions will gradually improve everywhere
overnight from north to south.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Freeze Watch from late Monday night through Tuesday morning for
SDZ049.
WY...None.
&&
$$
DISCUSSION...Bunkers
AVIATION...Helgeson