Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/10/19
AREA FORECAST DISCUSSION
National Weather Service Albany NY
939 PM EST Sat Mar 9 2019
.SYNOPSIS...
A low pressure system approaching from the south and west will
bring widespread precipitation to the area late tonight into
Sunday. Initially snow is expected, then will quickly transition
to a wintry mix Sunday morning, and then rain by Sunday
afternoon for most of the area. Blustery conditions with some
snow and rain showers will occur Sunday night into Monday in the
wake of the storm system.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Winter Weather Advisory now in effect for all areas for late
tonight through Sunday afternoon...
Wind Advisory for the southern Green Mountains, southwest
Adirondacks, central/northern Taconics and Berkshires for
Sunday...
As of 930 PM EST, high clouds are steadily increasing across the
region. Temps have dropped off in some northern and eastern
sheltered areas into the lower/mid 20s, while remaining
generally in the mid 20s to lower 30s elsewhere. Wind has
persisted in many areas before the high clouds arrived,
preventing temps from falling as much as previously forecast.
Where clouds remain somewhat thin, temps could still drop to
around 20 across portions of the southern Adirondacks and Glens
Falls area, southern VT and the Berkshires over the next couple
of hours, while only dropping to 25-30 elsewhere.
The clouds should thicken toward and especially after midnight,
tempering any falling temps, and in fact, as winds become
east/southeast, temps should start rising in some areas.
Models, most notably near-term models such as the RAP13, HRRR
and also HREFs continue suggest a slower onset of
precipitation, as the departing ridge axis sharpens in response
to strengthening pressure/height falls to our west. However, as
the leading edge of a potent low/mid level jet approaches,
expect precipitation to quickly overspread the region between
roughly 4 and 6 AM EDT from west to east. Thermal profiles
suggest mainly snow to start, although as a mid level warm nose
quickly advances northeast, some sleet could mix in as soon as
after an hour or two of snow from the Capital Region area of NY
and points south and west. Snowfall rates could be between one
half inch and one inch per hour while all snow occurs, so a
quick inch of snow is possible before the changeover to sleet in
these areas. Farther north and east, the snow will just be
starting, so accumulations through 6 AM EDT should remain under
an inch, although snow may be falling moderate to heavy at times
shortly after commencing.
East to southeast winds will increase across higher terrain
areas of the SW Adirondacks and eastern Catskills, with some
gusts of 30-40 mph possible toward 6 AM Sunday, with stronger
gusts possible shortly thereafter across the SW Adirondacks.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Sunday, a band (fitting the "laterally translating" paradigm
per CSTAR research) of moderate to locally heavy precipitation
should continue advancing quickly east/northeast between 6 and 8
AM EDT. Mainly snow is expected for the Mohawk Valley, southern
Adirondacks, and southern VT as this initially moves through,
with snowfall rates possibly as high as 1-1.5 inch/hour.
However, sleet should mix in after 1-2 hours of snow. Thus, a
quick 1-3 inches of snowfall is expected between roughly 6 and 8
AM EDT in these areas, with perhaps another 1-2 inches in
portions of the SE Adirondacks and higher elevations of southern
VT of snow/sleet after 8 AM EST. Elsewhere, mainly sleet and
freezing rain is expected through mid morning Sunday before
changing to plain rain from south to north. Ice accretion should
range from a trace, to up to one tenth of an inch, with
greatest amounts across higher terrain areas of the eastern
Catskills, Helderbergs, and Litchfield Hills.
As a strong low level jet segment translates across the region,
strong wind gusts of 40-50 mph will be possible across higher
terrain areas of the southern Greens, northern/central Taconics,
Berkshires, and SW Adirondacks (mainly extreme northern Herkimer
and Hamilton Counties) where a Wind Advisory is in effect from 6
AM EDT Sunday until 4 PM EDT. There is a possibility that the
advisory may need to be expanded slightly southward in time into
the southern Taconics and Litchfield Hills, and trends in
upstream observational data will need to be watched.
Despite the strong low level jet passing overhead, strong wet
bulbing of the initially dry and chilly air mass may create
quite a shallow low level cold pool that may be very difficult
to dislodge Sunday, particularly across northern areas such as
the southern Adirondacks, eastern/central Mohawk Valley, the
Lake George/Saratoga region and portions of southern Vermont
(especially higher terrain areas of eastern Bennington County)
east to the CT River Valley in SE VT, as well as across
northeast Berkshire County. In these areas, spotty light
freezing rain/freezing drizzle may persist into at least the
early to mid afternoon hours Sunday.
Elsewhere, after the initial burst of snow/sleet and some
freezing rain, expect only spotty light rain/drizzle and some
areas of fog for the afternoon hours.
Late afternoon high temps should range from the mid 30s portions
of the southern Adirondacks, eastern Mohawk Valley and Lake
George/Saratoga region into portions of southern VT and
northeast Berkshire County MA, to the upper 30s to lower 40s
elsewhere.
Sunday night-Monday, an occluded front should move across the
region Sunday evening with some rain showers in valley areas,
and snow showers across higher terrain areas. Some minor
accumulations of 1-2 inches could occur in northern Herkimer
County. Otherwise, expect a brief period of clearing for areas
south and east of I-90/I-88 Sunday night, with clouds and
lingering snow showers/flurries to the north and west. Clouds
should expand south and east during Monday, with persistent snow
showers across the SW Adirondacks, and isolated to scattered
snow/rain showers farther south and east into the Mohawk Valley
and southern VT. West to northwest winds will increase during
this period, with gusts of 25-35 mph developing later Sunday
night, and 35-45 mph Monday. Will have to watch for any deeper
mixing potential for Monday afternoon, as this would increase
the possibility for gusts to reach up to 50 mph, especially
within the Mohawk Valley/Capital Region and Berkshires. If this
potential increases, then a Wind Advisory would be issued for
these areas. Lows Sunday night mainly in the 30s for lower
elevations, and upper 20s across higher terrain. Highs Monday
reaching 40-45 in most valley areas, with 30s across higher
elevations, where temps may fall during the afternoon.
Monday night-Tuesday, as the upper level trough passes through
Monday night, snow showers may increase in areal coverage before
diminishing later at night into Tuesday, and contracting to
areas closer central NYS with a veering low level wind flow.
Expect increasing sunshine for Tuesday after some morning
flurries/snow showers across western areas. It will be breezy,
but not quite as windy as Monday, with highs reaching the mid
30s to near 40 in valley areas, and 25-30 across most higher
elevations.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The period starts out Tuesday night with a ridge of high pressure
both at the surface and aloft building eastward across the region.
With light winds and clear skies this will result in a cold night.
After a cool start to the day Wednesday, temperatures will moderate
to near normal levels during the afternoon as the surface
anticyclone shifts eastward off the coast and a return southerly
flow develops. The upper level ridge will remain in place though, so
dry conditions will persist with minimal cloud cover.
The upper ridge axis will then move over the region Wednesday night,
and shift east of our area on Thursday. This is when temperatures
are expected to warm to above normal levels, due to strengthening
low level southwest flow. Model guidance (especially the 12Z ECMWF)
has backed off on any precip through at least the first half of
Thursday, so will mention dry conditions through early afternoon
then introduce a chance of showers late in the day as a frontal
boundary approaches.
Will trend forecast towards slower ECMWF for Thursday night into
Friday, with mainly chance pops for rain showers, as a weak boundary
meanders across the region. Ahead of this boundary, temperatures
could soar well into the 50s across much of the area and could reach
60s in some parts of the Hudson Valley. A deep snow pack will limit
significant warming in higher terrain areas though. QPF looks too
high from the GFS at this time, with only weak forcing present.
The first in a series of cold fronts will push through Friday night,
with some tempered cooling behind this boundary and some light
showers. Additional showers will be possible on Saturday associated
with another cold front. Temperatures expected to cool closer to
normal on Saturday.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
High pressure will remain in control through this evening and
into the overnight hours. A low pressure system will then track
into the Great Lakes region, with a warm front approaching from
the south and west during Sunday.
Clear to partly cloudy skies are expected through about 08Z/Sun
with VFR conditions.
Clouds will quickly thicken thereafter, with precipitation
quickly developing between 10Z-12Z/Sun from southwest to
northeast. Vsbys should quickly drop to IFR as precipitation
begins (mainly as snow and/or sleet), with MVFR Vsbys.
Initially, the precipitation should start as a
snow/sleet mix at KALB, KPSF and KPOU, before changing to
mainly sleet, then freezing rain and sleet between roughly 12Z-
14Z/Sun. Snow/sleet accumulations of around an inch, and a light
glaze is expected at KALB and KPOU before precipitation changes
to plain rain by 15Z/Sun. At KPSF, freezing rain may linger
until 18Z/Sun before changing to light rain or drizzle.
At KGFL, where cold air will be a bit more pronounced,
precipitation should start as snow, and could be briefly
moderate to heavy, before mixing with and/or changing to sleet
between 14Z-16Z/Sun, then freezing rain and sleet between 16Z-
19Z/Sun. After 19Z/Sun, mainly light rain or drizzle is
expected. Snow/sleet accumulations of 1-3 inches are possible at
KGFL, along with ice accumulations of up to one tenth of an
inch.
For Sunday afternoon, steady precipitation should taper off to
patchy drizzle or rain showers. However, MVFR Cigs will persist,
with VFR to MVFR Vsbys.
Winds will be variable around 5 kt or less, becoming east-
southeast around 8-12 kt by early Sunday morning. A
southeasterly low-level jet is expected to move over the region
Sunday morning, which will allow for low level wind shear to
develop, especially at KPOU/KPSF where wind speeds aloft should
be strongest.
Winds may become more northerly at KGFL during the morning and
into the afternoon due to localized terrain effects.
Outlook...
Sunday Night: Moderate Operational Impact. Chance of SHRA.
Monday: Moderate Operational Impact. Windy With Gusts To 35.0
Slight Chance of SHRA...SHSN.
Monday Night: Moderate Operational Impact. Breezy Chance of SHSN.
Tuesday: Low Operational Impact. Breezy NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SHRA.
.HYDROLOGY...
No hydrologic issues are anticipated through the middle of next
week.
A moderating trend is expected over the weekend into next week
to near seasonable levels. However, snowmelt is expected to
remain negligible, especially across higher terrain areas the
seasonable temperatures will only act to slightly ripen the
existing snowpack.
A low pressure system will bring widespread precipitation to
the area late tonight into Sunday. Current forecast is for
around a half inch across most of the area, to about two-thirds
of an inch across far southern portions of the area. At least
half of that amount is expected to fall as snow/sleet. Other
than some lake effect snow in some areas on Monday, dry
conditions are expected until late next week.
There are some signs for above normal temperatures later next
week, which could result in more significant snowmelt and river
rises/ice movement, depending on the magnitude of the warm air
and how long it will last.
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...Winter Weather Advisory from 4 AM to 1 PM EDT Sunday for
CTZ001-013.
NY...Winter Weather Advisory from 4 AM to 1 PM EDT Sunday for
NYZ047>054-058>061-063>066.
Wind Advisory from 6 AM to 4 PM EDT Sunday for NYZ032-033-054-
061.
Winter Weather Advisory from 4 AM to 5 PM EDT Sunday for
NYZ032-033-038>043-082>084.
MA...Winter Weather Advisory from 4 AM to 1 PM EDT Sunday for
MAZ025.
Wind Advisory from 6 AM to 4 PM EDT Sunday for MAZ001-025.
Winter Weather Advisory from 4 AM to 5 PM EDT Sunday for
MAZ001.
VT...Wind Advisory from 6 AM to 4 PM EDT Sunday for VTZ013-014.
Winter Weather Advisory from 4 AM to 5 PM EDT Sunday for
VTZ013>015.
&&
$$
SYNOPSIS...KL/NAS
NEAR TERM...KL
SHORT TERM...KL/DBT
LONG TERM...JPV
AVIATION...KL/JPV
HYDROLOGY...KL/NAS
Area Forecast Discussion...CORRECTED
National Weather Service Gaylord MI
942 PM EST Sat Mar 9 2019
.UPDATE...
Issued at 942 PM EST Sat Mar 9 2019
There are many, many ways in which this forecast could go awry.
Right out of the gate, the only county without an advisory
(Manistee) is seeing advisory-level wind gusts (49 mph peak gust at
MBL) as precip (liquid, at least at MBL) starts to move in. There
are some power outages in that area. That`s small potatoes
compared to the briefly (very) heavy wintry mix lifting into the
area. Highest QPF during the night remains in the sw half of the
forecast area, and in particular Gladwin/HTL/W Branch - the newest
RAP dumps almost exactly an inch of liquid precip on top of HTL
tonight (though the HRRR is far less wet). That high- end QPF
forecast looks far, far too wet. Various model soundings in this
area are riding the ragged edge of snow vs sleet vs freezing rain,
though with the latter two being favored.
Not sure the se zones (HTL-W Branch) see a quick burst of all
snow at the beginning, and will back off a bit on snow there to
add more sleet and even a touch of ice. However, there are no
locales that reach 0.25" of ice accum. Will add Manistee Co to the
advisory for a few hours (added to the group that expires at 1
am EST). Updated advisory will also play up the easterly winds
tonight a bit more.
Otherwise, changes to this point are minor.
&&
.NEAR TERM...(Through Tonight)
Issued at 347 PM EST Sat Mar 9 2019
...Another unfavorable storm track for easy precipitation type
forecasting tonight...
High Impact Weather Potential: Another precipitation type
nightmare...with a lot of possibilities.
Pattern Synopsis/Forecast: Early afternoon surface analysis shows
991mb low near Kansas City...with 7-8mb/3h pressure falls over
northeast Missouri/northwest Illinois (barograph is stair-
stepping downward rather sharply this afternoon). This low is
expected to make more of a northeast turn this evening toward
southern Lake Michigan...eventually winding up in the vicinity of
Grand Traverse Bay by Sunday morning. Expansive band of
precipitation continues to push northeast out of the Mississippi
Valley and toward the upper Great Lakes...with rain spreading
across Indiana/northern Illinois. Meanwhile a rather pleasant
afternoon across northern Michigan with a thickening blanket of
high clouds and some gusty east- southeast winds...but
temperatures have warmed nicely with a few spots (TVC/ACB) having
touched 40. But dew points are down in the single digits and
teens...these 20-30 degree dew point depressions will prove
problematic for tonight`s precip type forecast.
Primary Forecast Concerns: Approaching system from the southwest
will be pushing precipitation and warmer air north tonight...the
combination of a developing elevated warm nose and much uncertainty
regarding how low wet-bulbing temperatures will go make the precip-
type forecast a bit tricky.
Eastern Upper...Expect areas above the bridge to remain dry through
early evening before precipitation advances in from the southwest
during the mid-late evening hours. Precipitation should be
widespread into the early morning hours before some semblance of dry
slotting may turn things more freezing drizzly or showery for a
time. Precipitation type in general should be mostly snow though
warm nose may sneak into far eastern Upper late tonight. Gusty
easterly winds will create some issues with blowing/drifting snow as
well...though overall snowfall should be on the wetter/more dense
side given nearly 400mb deep layer of temperatures above -10c (more
accretion/aggregation/riming cutting down on snow-liquid ratios).
Think a solid 2-4 inches is a decent range for snow totals tonight.
Northern Lower...Precipitation type much more problematic here given
initial dry low levels as mentioned above...so an initial warm layer
aloft may erode quickly once precipitation starts especially across
interior northern Lower. There could be a decent burst of snow at
the onset of the precipitation from the M-55 north to the M-32
corridor and east of M-37 where a quick 3-4 inch burst of snow not
out of the realm of possibility. West of M-37 precipitation
precipitation could start as snow/sleet before changing to rain/
freezing rain. Again how far surface temperatures drop is an
unknown given large temperature/dew point spreads...but it seems
reasonable that temperatures may hang around or a bit below freezing
for a good part of the night in the hills of Grand Traverse/Wexford
Counties. So eventually some ice accumulation may be problematic...
but a lot of uncertainty here. Heading north of M-72 expect
precipitation to spread in as the evening progresses...likely to
fall as mostly snow (some sleet at the onset with evaporative
cooling)...eventually transitioning to more liquid precipitation
during the pre-dawn hours. Again...like eastern Upper some mid
level drying will complicate precipitation types with some periods
of freezing drizzle overnight. As temperatures warm aloft higher
terrain areas across interior northern Lower may hang around
freezing for a longer period of time. Also with gusty winds some
blowing snow issues probable.
Headlines...Will re-jigger the headlines around spatially and
temporally (reason number 400 why I`m not a fan of second period
advisories). Will push the start time of the eastern Upper advisory
into late evening...end time of Sunday afternoon will remain the
same. Not comfortable ending much of the northern Lower advisory
this evening...especially if surface temperatures are slow to
recover (e.g., higher terrain) and there ends up being a longer
potential window for freezing rain/icing. The exception will be
Gladwin/Arenac counties which will be added to the advisory (matches
DTX) but just through 05z. Otherwise it`s easier to cancel early if
conditions improve rather than trying to decide whether to extend a
headline farther out in time. Nor am I comfortable leaving Grand
Traverse and Leelanau counties out of the advisory...the latter in
particular since they may see more frozen/freezing precip types much
of the night and Sunday morning (they will be chunked in with the
far northwest Lower advisory that runs through Sunday). Grand
Traverse and Benzie will be added through 05z and then the headline
can be re-evaluated (especially with respect to interior Grand
Traverse County). Will leave Manistee county alone for now.
&&
.SHORT TERM...(Sunday through Tuesday)
Issued at 347 PM EST Sat Mar 9 2019
High Impact Weather Potential....Mainly moderate snow in E Upper
as the freezing rain departs by the early morning.
Pattern Synopsis/Forecast...The models came in colder today, too as
the track shifted a little more south than yesterday at this time.
By 12z/Sun the sfc low is somewhere between the Bridge and KPZQ as
depicted by the GFS and ECMWF (or KCVX if you throw in the 12z NAM
or near Atlanta on the 18z NAM), so some where north of M-32. This
pushes the 850 mb cold air off the Lake Huron shoreline and with the
moisture in the 850-700 and 700-500 layers > above 85% will figure
that the chance for freezing precipitation will be done, and snow or
a rain/snow mix will be the case. The 850 mb temperatures are around
-8c and the water either frozen or around +2c where the water is
open. Think that lake enhancement low as the instability will be 10C
or less to start, but pick up as the temperatures drop overnight to
around -11c by 12z/Mon.
Monday, the 850 mb temperatures are dropping to around -13c, with
moisture in the 850-700 mb layer around 55%. So there will be some
LES as the system continues to move NE out of the Great Lakes. The
RH in the layer will continue to dry out through the day, so will
expect that the LES will diminish. Monday night, the 850 mb
temperatures warm to -5c by 12z/Tue and the rh in the layer drops to
< 20% so will expect that all the snow will stop sometime in the
evening or overnight.
Primary Forecast Concerns...Snow amounts look to be light to
moderate as the rain/snow mix changes to the snow in E Upper and N
lower. The amounts in N lower will be light as it will take a little
longer to transition to all snow. The wind gusts continue to not
show much over 40 mph as the models are showing 30-35 knots at 950
mb and 925mb Sunday evening. This makes the the winds getting to 15
to 25 mph with gusts to 35-40 mph, so that the areas of blowing and
drifting are expected. If there is a trouble spot, it could be
around KCVX as the winds over the ice/snow blow onshore and cause
issues wind gusts could be 40-45 mph from around Grand Traverse
light to near Bay Harbor if the HiResW models are right.
.LONG TERM...(Tuesday night through Saturday)
Issued at 347 PM EST Sat Mar 9 2019
High Impact Weather Potential...A storm on Wednesday/Thursday could
bring a mix of rain and snow.
Extended (Tuesday through Saturday)...Tuesday will be a quiet day as
the high pressure from Monday moves through the Upper Great Lakes.
Tuesday night, the next system begins to moves into the region, and
spreads snow during the evening and overnight. Wednesday, the system
moves into the C Plains, and continues to spread the precipitation
around the Upper Great Lakes. This one looks like it is mostly rain,
with the threat of a mix as we head into Thursday and Thursday
evening. The 500 mb low doesn`t move into the Upper Great Lakes
until Friday, which is more likely for the mix. Friday night, the
mix will turn to snow, and the snow will continue into Saturday as a
500 mb low drops into the Upper Great Lakes and brings another
chilly shot of cold air.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 626 PM EST Sat Mar 9 2019
Deteriorating conditions from south to north tonight.
Low pressure will move ne from the mid-MS Valley, and will be near
TVC at 12Z. Mixed precip will advance northward into the region,
falling initially as mostly snow, then mixing with sleet, freezing
rain, and just rain. Places further south (MBL) will see more in
the liquid precip, while further north (PLN) will see more in the
way of snow. IFR conditions will eventually develop, and LIFR is
at least briefly possible. Mix snow and rain will linger for much
of Sunday.
Gusty e/ese winds will diminish somewhat late tonight as the low
approaches. Gusty west winds return behind the low on Sunday.
LLWS tonight.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY until 6 AM EDT Sunday for MIZ017-018-023-
024-027>030-032>036.
WINTER WEATHER ADVISORY until 6 PM EDT Sunday for MIZ016-019>022.
WINTER WEATHER ADVISORY until 1 AM EST Sunday for MIZ025-026-041-
042.
WINTER WEATHER ADVISORY until 6 PM EDT Sunday for MIZ008-015.
&&
$$
UPDATE...JZ
NEAR TERM...JPB
SHORT TERM...JL
LONG TERM...JL
AVIATION...JZ
Area Forecast Discussion
National Weather Service Boston/Norton MA
946 PM EST Sat Mar 9 2019
.SYNOPSIS...
High pressure exiting E overnight as clouds spread across the
region. A wintry mix for Sunday morning changing over to rain
as late as Sunday afternoon out ahead of a storm sweeping across
the Great Lakes. High pressure slowly builds over the region,
cresting on Wednesday and moving off to the east Thursday. This
will mean dry weather and seasonable temperatures through most
of the workweek. A storm ejecting from south of California will
move through the Great Lakes Friday, spreading rain over
Southern New England with lingering showers Saturday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
945 pm update...
Previous forecast is on track. An abundance of mid level
cloudiness will be overspreading the region from the west over
the next few hours. This should keep temperatures mainly steady
in the middle 20s to the lower 30s overnight. Dry weather should
prevail overnight through about 5 am, before a burst of
snow/sleet overspreads the region through mid morning Sunday.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ Highlights ...
- Wintry mix onset Sunday morning, eroding N with warmer air
- WINTER WEATHER ADVISORIES for N CT, NW RI, Central and W MA
- Blustery SE winds with gusts to 40 mph across coastal MA and RI
- Possible roadway water ponding SE MA / RI per snow-clogged drains
*/ Overview ...
Warm-frontal upslope / over-running event associated with an inside-
runner Great Lakes storm. Preceding cold air damming and N drainage
winds especially for the CT / Pioneer River Valleys, forecasting an
onset snow early Sunday morning transitioning to sleet / freezing
rain then to plain rain over the interior, while transitioning to
sleet then to rain across the coast / coastal plains throughout the
morning hours into afternoon, concluding towards evening. Generally
speaking, a coating to around 3 inches of snow / sleet for most of S
New England. A trace and not going above a tenth of an inch of ice
accretion for NW RI, N CT, W and Central MA where a WINTER WEATHER
ADVISORY remains posted. GALE WARNINGS expanded over the S waters.
*/ Details (associated with 12z guidance) ...
Thermal fields ... SE Canada situated high pressure with interior low
pressure over the Great Lakes, shallow cold air drainage with H97-95
ageostrophic / isallobaric flow especially over CT / Pioneer Valley.
More of an E onshore component over S/E New England. Meanwhile over-
running warm nose around H8, subtle nuances / model differences, how-
ever leading into the event, global model H85-7 thicknesses colder
than high-res guidance. Same can be said with the maximum wet-bulb
temperature within the H9-5 layer. Prior forecaster made mention as
to the NAM tending to do well with mid-level warm noses, however the
forecast may be complicated by forcing / dynamic cooling that delays
onset of warmer air yielding more snow or sleet, plus aforementioned
cold air drainage aiding with colder low-levels and subsequent re-
freezing towards sleet. Perhaps precip-transition delays also by
signaled surface - H85 pressure falls sweeping over SE New England
Sunday afternoon that could hold longer / tuck colder air over CT /
Pioneer River Valleys. Preference to colder 1000-850 mb thicknesses
while warmer 850-700 mb thicknesses suggested by high-res guidance.
Forcing ... Speaking of, model consensus warm-frontal over-running
ascent and convergent mid-level SW winds yielding NW-SE H5-7 fronto-
genesis extending through the snow growth region with 15-25 microbar
per second omega early Sunday morning. SREF suggesting a brief burst
of snow / sleet with low probabilites of 1" per hour snowfall rates
over N/W MA and N/W CT. Both less than the prior event last weekend.
Frontogenesis transitioning to H925-85 coincident with surface - H85
1 to 2 mb per hour pressure falls sweeping across SE New England by
Sunday afternoon, subsequently aided by H925-85 low-level convergent
wind enhancement. Considering this along with forecast precipitable
waters around 0.75 inches, running +1-2 standard deviations above
average for early March, there`s a question as to how much liquid
equivalent will result.
Precipitation ... So compared to the last weekend`s event, forcing
not as robust however a more moist environment. Model consensus has
generally 0.40 to 0.80 storm-total liquid with highest amounts over
S/SE-coastal New England. But looking at model soundings along with
the latest HRRR / RAP model output, lot of dry air to overcome below
H5 initially. Onset by a few hours later into Sunday morning mainly
beginning after sunrise. A daytime event, lowered slightly snow
totals but kept ice totals roughly the same. Slight uptick in liquid
equivalent given +3-4 standard deviation above average H85 moisture
flux.
Winds ... Surface to H85 pressure falls over SE New England coupled
with a localized enhancement in H925-85 low-level winds in proximity,
while taking into account a stout inversion, still expect gradient-
driven SE winds of 30 to 40 mph centered around midday Sunday over
coastal MA and RI as well as adjacent waters. Roughly 20 to 30 mph
over the coastal plains and high terrain. Closer to high-res and MOS
guidance with respect to CT / Pioneer River Valley winds preferring
a N-drainage flow. As pointed out by the prior forecaster, a +2-3
standard deviation above average of H925-85 winds.
Hazards ... Given an average 1 to 2 inches of snow-water equivalent
in the snowpack, especially over interior SE New England which saw
around 8 to 14 inches last Monday, clogging drains as solid walls of
ice along roadways, can`t rule out ponding of water along roadways
in isolated spots. Snow ratios 8-12:1 and sleet ratios 2-3:1, a
consensus blended with aforementioned storm-total liquid, yields a
coating up to around 2 inches of snow / sleet, highest amounts up to
3 inches over the N Berkshires. High-res preference of thicknesses,
layer maximum wet-bulb, and 2m temperatures, a trace up to a tenth
of ice accretion over NW RI, N CT, W and Central MA. Opted not to
expanded E as consensus has icing mostly W of the MA I-495 beltway.
Yes, there`s icing in the forecast around I-495 but think the impact
will be minimal during the daylight hours compared to the W where
winter weather headlines exist. Expansion of GALE WARNINGS on the
waters per wind discussion above.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Big Picture...
Longwave scale shows trough west and ridge east at the start of the
week, which then transitions to ridge west and trough east late
week. A two-part shortwave trough lingers over the Northeast USA
Monday-Tuesday before moving off in favor of a ridge that covers the
Eastern USA. Closed low along the California coast sweeps south to
Northern Mexico, then ejects northeast midweek and crosses the Great
Lakes by Friday.
Contour heights at 500 mb over New England are a little below normal
Monday-Tuesday, then climb above normal Wednesday through Friday.
Expect, after a cool start to the week, a warming trend through the
rest of the week.
Model mass fields are in good agreement through Thursday morning.
Upper contour fields then diverge for the end of the week, while sea-
level isobars remain similar in indicating a Great Lakes storm with
New England in a mild airflow. Confidence in the forecast is high
through Thursday and moderate Friday. Low confidence Saturday.
Concerns...
Monday through Thursday...
One shortwave moves off to the east Monday. A second shortwave
sweeps through New England Monday night-Tuesday. Cold advection
Monday afternoon and night with coldest temps at 500 mb at -30C
Monday night. Warming temps aloft Tuesday. Moisture cross sections
show increasing moisture 925 mb to 700 mb Monday night which then
dissipates on Tuesday. Expect a period of partly cloudy skies.
Flurries possible especially in the hills.
High pressure then builds over the region. Expect mostly clear skies
and light wind from Tuesday night through Thursday morning. Cross
sections show increasing moisture above 700 mb Thursday afternoon
but lots of dry air below 700 mb. We will forecast dry weather
through Thursday afternoon, then chance pops for showers Thursday
night.
Friday-Saturday...
Low pressure ejects from Northern Mexico, crossing the Great Lakes
Friday and sweeping a cold front across our area Friday night-
Saturday. New England is in a southwest flow and the temperature
column is above freezing from surface to well above 800 mb. High
pressure is over the ocean, with no mechanism to hold in low-level
cold air. Expect showers, possibly as early as Thursday night and
more likely Friday-Saturday. Convective parameters show a weak theta-
e ridge Friday and total-totals around 50, while LI values remain
above 5. Will keep an eye on potential for thunder, but too early to
forecast with confidence.
Pacific atmospheric river feeds into the West Coast storm as it
moves into Northern Mexico. Once the storm crosses into the Plains,
it draws upon more moisture coming out of the Gulf of Mexico.
Interesting to see GFS forecast of 2 inch precip water values over
Western Louisiana Wednesday afternoon. Per sounding climatology,
that is 2-3 std deviations above normal for them this time of year!
Most of this moisture becomes trapped in convection over the Deep
South. But values of 1 to 1.25 inches reach to Southern New England
by Friday, which is 2-3 std deviations above normal for us as well.
This suggest a potential for downpours with this front, and will
also need to be monitored.
Final shortwave moves through the Northeast USA Saturday, but each
model shows a different location. For now we will show chance pops
across the northern half of our area.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Sunday Night/...High confidence.
Tonight ... Mostly clear skies to start, but clouds increase
during the night. Bases are above 15K through midnight and then
lower overnight. VSBYs lower towards morning in the west to
MVFR with onset of a wintry mix (SN/PL/FZRA) towards 12z,
coastal RA. Coastal E/SE winds increasing 10 to 15 kts with
potential gusts up to 30 kts along S-coastal terminals. Lighter
5 to 10 kt interior N drainage flow, mainly within N/W MA and CT
terminals.
Sunday ...
CIGs and VSBYs IFR-LIFR with wintry mix transitioning over to all
RA northward morning into afternoon. E/SE winds 10 to 20 kts with
gusts up to 35 kts morning into afternoon pushing further W into
the interior with only the CT / Pioneer River Valley hold with
lighter N winds, transitioning W/SW late and becoming light. LLWS
threats developing late morning into afternoon with S winds 50-60
kts at 2 kft agl, especially over S/SE MA and all of RI terminals.
Sunday night ...
Winds shifting W as terminal conditions improve towards VFR. IFR-
MVFR CIG and VSBY conditions lingering across E / SE coastal
terminals as late as roughly 6z Monday.
KBOS Terminal...
SN/PL developing around 12z Sunday, mixing with RA closer to 15z,
turning all RA by 18z. Potential LLWS threats briefly around 22z
with 180/50kt 2 kft agl. Clearing out and threats diminishing
by 0z Monday.
KBDL Terminal...
SN/PL developing around 11z Sunday, mixing with FZRA briefly towards
18z by which point all RA prevailing. N flow through Sunday afternoon,
overall light around 5 to 10 kts. Will see an improving trend
beginning 22-0z Sunday into Monday as winds shift W.
Outlook /Monday through Thursday/...
Monday through Monday Night: VFR. Windy with local gusts up to
30 kt.
Tuesday: VFR. Windy with areas of gusts up to 30 kt.
Tuesday Night: VFR. Breezy.
Wednesday through Thursday: VFR.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Sunday Night/...High confidence.
GALE WARNINGS expanded over the S waters. While the main storm
center sweeps across the Great Lakes, a secondary low may take
shape over SE New England. A local enhancement in the wind profile
aloft in addition to pressure falls should increase the local
gradient wind profile. SE winds gusting up to 40 kts pushing 8
to 12 feet, the height of both around Sunday afternoon into
Sunday evening. Winds should begin to diminish as they shift out
of the W Sunday night allowing seas to subside.
Outlook /Monday through Thursday/...
Monday: Moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Areas of rough seas.
Monday Night: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Seas up to 5 ft.
Tuesday: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Local rough seas.
Tuesday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft.
Wednesday through Thursday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Weather Advisory from 5 AM to 2 PM EDT Sunday for
CTZ002>004.
MA...Winter Weather Advisory from 5 AM to 2 PM EDT Sunday for
MAZ002>004-008>012-026.
RI...Winter Weather Advisory from 5 AM to 2 PM EDT Sunday for
RIZ001.
MARINE...Gale Warning from 1 PM to 8 PM EDT Sunday for ANZ231>234.
Small Craft Advisory from 6 AM Sunday to 2 AM EDT Monday for
ANZ230-236.
Gale Warning from 10 AM to 6 PM EDT Sunday for ANZ235-237.
Gale Warning from 10 AM to 10 PM EDT Sunday for ANZ250-254-255.
Small Craft Advisory from 6 AM Sunday to 8 AM EDT Monday for
ANZ251.
Gale Warning from 7 AM to 6 PM EDT Sunday for ANZ256.
&&
$$
SYNOPSIS...WTB/Sipprell
NEAR TERM...Frank
SHORT TERM...Sipprell
LONG TERM...WTB
AVIATION...WTB/Sipprell
MARINE...WTB/Sipprell
Area Forecast Discussion
National Weather Service Billings MT
835 PM MST Sat Mar 9 2019
.UPDATE...
Area of snow showers extending from the Beartooth/Absarokas to the
Bighorns is dissipating, and skies are mostly clear across the
remainder of the region. Have reduced pops based on latest radar
trends. Livingston has already fallen to 5 degrees so have dropped
their expected low a bit...but would anticipate temps bouncing
around through the night. HRRR has backed off on fog development
later tonight but not quite buying it as daytime snow melt added
moisture to the boundary layer, and skies are generally clear.
Will sustain patchy fog in the forecast from 06-15z, mainly in
river valleys. JKL
&&
.SHORT TERM...valid for Sun and Mon...
Skies have cleared across a good portion of our forecast area
this afternoon as the shortwave responsible for last night`s snow
has moved east. An elongated upper low exists to our west,
extending from Oregon to western Montana. Lapse rates are fairly
steep underneath this low, and latest satellite imagery shows
convective snow showers developing over central Idaho and western
Montana. BLX radar shows snow showers over the Beartooth Absarokas
with a band extending to near Columbus.
Scattered snow showers and flurries will continue across our
western and southern mountains and foothills from now through mid
evening. Models do not paint QPF as far off the foothills as
Billings, but quick look at a HRRR forecast sounding shows steep
lapse rates moistening thru the dendritic layer, so feel we could
see some late afternoon and evening flurries here locally. Any
lower elevation accumulation should stay less than an inch, but
mountains could see a fast inch or two in heavier snow showers.
Eastern areas will be dry this evening, and all lower elevations
will be dry overnight. The combination of recent precipitation and
daytime snow melt will bring the potential for fog tonight. HRRR
shows splotchy fog in our east only, but feel the boundary layer
is moist enough that western valleys could radiate cold enough for
some fog as well.
Upper low to our west will settle over the southwest CONUS and the
resulting split flow will bring us dry and warmer conditions
Sunday and Monday. Highs in the 30s tomorrow should warm to the
upper 30s and 40s for a good portion of our forecast area by the
beginning of the work week. Of course, the abundant snow cover
will make forecasting temperatures difficult, but as 850mb temps
rise to a few degrees above zero would be surprised if the
foothills don`t see 50 degrees on Monday. Winds will also be on
the increase in our west and that will help with the warming, as
well as the snow melt, and will need to keep an eye on water
runoff and/or ice jam issues over the next few days.
JKL
.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...
A split flow aloft along with weak ridging on Tuesday will give
way to a southwest flow aloft as an upper low and trough move onto
the Pacific Northwest coast into the Great Basin area. Dry
conditions and mild temperatures will continue on Tuesday with
temperatures looking to be the warmest day in the extended with
30s to lower 40s common.
Models organize this trough and upper low over the four corners
region and southern plains on Wednesday then shift it northeast
across the central plains and midwest during the day Thursday.
This storm track is further east than what models were showing
yesterday. As a result, the heaviest precipitation looks to remain
east of Montana, although the southeast portions of the state
will still need to keep an eye on this track. However, general
troughiness will be over the northern rockies along with an upper
low over Idaho during this time. This will result in temperatures
cooling back into the 20s and 30s along with a chance for snow
across our forecast area Wednesday and Thursday. Models then bring
weak ridging, a dry northwest flow aloft, along with some
moderating temperatures for Friday into next Saturday. Hooley
&&
.AVIATION...
Patchy fog and LIFR-IFR conditions are possible over southern MT
and north central WY after 06z Sunday. This will be mainly in the
river valleys. The best chance to impact a terminal will be
around KMLS, but cannot rule it out around KBIL and KSHR.
Otherwise, VFR will prevail at area terminals tonight. Ongoing
snow over the mountains will taper to scattered snow showers later
tonight...but mountains will remain obscured through the night.
RMS/Reimer
&&
.PRELIMINARY POINT TEMP/POPS...
Sun Mon Tue Wed Thu Fri Sat
-----------------------------------------------------------
BIL 013/034 018/042 022/042 020/037 022/034 015/035 017/037
00/U 00/U 00/U 13/O 41/E 10/B 10/B
LVM 002/035 010/041 014/037 016/029 014/029 010/032 013/035
00/U 00/N 00/U 24/S 21/E 01/U 11/B
HDN 005/033 006/039 013/041 015/036 019/034 010/034 012/035
00/U 00/U 00/U 14/S 52/S 10/B 00/B
MLS 006/028 005/034 013/037 015/033 020/030 012/030 011/030
00/U 00/U 00/U 13/S 41/N 00/B 00/B
4BQ 005/032 006/039 015/041 014/034 019/031 012/032 012/033
00/U 00/U 00/U 03/S 52/S 00/B 00/B
BHK 006/027 005/035 018/037 016/031 020/029 012/027 009/028
00/B 00/U 00/U 02/S 32/S 00/B 00/B
SHR 009/034 009/043 018/044 018/034 019/031 012/034 014/036
10/U 00/U 00/U 03/S 53/S 10/B 00/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Quad Cities IA IL
749 PM CST Sat Mar 9 2019
.UPDATE...
Issued at 745 PM CST Sat Mar 9 2019
Have expanded the wind advisory to include counties along the
Highway 20 corridor. Latest trends with the RAP, HRRR and NAM
indicate periods where winds will increase into advisory criteria
later tonight and Sunday morning.
&&
.SYNOPSIS...
Issued at 311 PM CST Sat Mar 9 2019
A strong, negatively tilted upper level shortwave was located over
north central MO into south central IA at 3 pm. At the surface, the
low was just north of Kansas City. An axis of strong 3 hour pressure
falls of 9 mb/3 hours was centered near Peoria, with a tight
pressure gradient around the entire system leading to strong gusty
winds. Area radars showed the dry slot lifting the initial axis of
warm advection rains north of I-80, while showers and thunderstorms,
some with small hail, were advancing through northeast Missouri,
southeast Iowa and west central Illinois, driven by steep mid level
lapse rates and strong mid and upper level forcing ahead of the
shortwave. As the low tracks east-northeast, the local area will
have showers and thunderstorms, then possible dense fog, followed by
strong winds in the cold air advection and pressure rises in its
wake.
&&
.SHORT TERM...(This Evening through Sunday)
ISSUED AT 311 PM CST Sat Mar 9 2019
Bottom Line Up Front
Will be hoisting a wind advisory for all but the Highway 20 corridor
for tonight. The possibility does exist that the wind advisory may
have to be extended into Sunday.
Also, there has been some persistent dense fog to the north and
northeast near the main surface low. There may or may not be a need
for a headline regarding the fog this evening prior to the winds
coming up.
Tonight
Assessment...medium confidence on precipitation timing. High
confidence on the potential for high impact weather.
Based on pressure falls, the main low looks to pass between Cedar
Rapids and the Quad Cities.
As the low moves up through the area, the risk for thunderstorms
will dissipate during the evening. Also, there is a potential for
dense fog to develop near the low as it moves through the area.
Starting around mid-evening precipitation will end from south to
north and winds will increase. Based on winds across Kansas wind
gusts up to 45 mph are expected and a few gusts may reach 50 mph.
Some snow is possible prior to the rain ending in the highway 20
corridor. Amounts would be a dusting at best.
On Sunday, windy and dry conditions are expected as cold air moves
into the area. I cannot completely rule out the possibility of some
flurries occurring during the morning hours.
.LONG TERM...(Sunday Night through Saturday)
ISSUED AT 311 PM CST Sat Mar 9 2019
Sunday night through Monday night
Assessment...high confidence
Quiet and dry conditions will be seen as high pressure quickly moves
through the Midwest. Temperatures will average below normal.
Tuesday
Assessment...low to medium confidence
The first part of a more significant storm system will move through
the area. There are differences between the models in regards to the
timing of this system. The ECMWF and CMC global bring the first part
in Tuesday afternoon while the GFS and FV3 bring the first part in
Tuesday morning.
As a result of these differences the model consensus has slight
chance to chance pops all day Tuesday. If the first part of the
storm system arrives Tuesday morning, precipitation will be in the
form of snow that changes to rain. If the system arrives in the
afternoon, precipitation will be in the form of all rain.
Tuesday night on...
Tuesday night through Thursday
Assessment...high confidence on a storm occurring. Low confidence
on the track and precipitation type.
Another significant storm system will affect the Midwest Tuesday
night through Wednesday night. All global models have the main
surface low passing through the western half of Iowa and moving into
Minnesota. Such a track would place the area in the warm sector with
precipitation having a high probability of being all rain. Warm air
being pulled north would also bring the risk of some thunderstorms
as well as temperatures averaging above normal.
However, there are some differences in timing with the storm system.
Right now the model consensus has likely to categorical pops Tuesday
night through Wednesday night. For Thursday the model consensus has
slight chance to likely pops with the highest pops over the
northwest third of the area.
The bulk of the rainfall looks to be centered around late Tuesday
night through Wednesday evening.
Thursday night through Friday night
Assessment...low confidence
A fairly strong upper level disturbance will move through the
Midwest. However, there are differences in the overall timing of the
disturbance moving through the Midwest. Colder air aloft will create
an unstable atmosphere and forcing acting upon the available
moisture should be enough to generate light precipitation across the
area.
The model consensus has slight chance to chance pops Thursday night
through Friday night for much of the area. Precipitation should be
mainly rain during the daytime but may mix with or change to all
snow at night.
Saturday
Assessment...medium confidence
The model consensus has dry conditions for the area as the next high
pressure starts moving through the Midwest. Temperatures will
average below normal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
ISSUED AT 529 PM CST Sat Mar 9 2019
Strong area of low pressure moving from northern Missouri to central
Illinois will keep poor flying conditions in place for much of
this TAF period. Area of rain and snow currently impacting
KDBQ/KMLI/KBRL will move out of the area this evening, with dry
conditions expected by 10/02z. As the low moves by, there will be
the potential for some areas of fog as winds briefly diminish.
Current KCID ob is showing misty conditions with MVFR visibility,
so included a TEMPO group there through 10/02z. Any fog potential
will be short lived as west winds quickly pick up after the low
pressure passes, with gusts up to 30 kts at times. Conditions
will slowly improve across the area Sunday, with several models
hinting at VFR by 10/18z.
&&
.HYDROLOGY...
Issued at 1134 AM CST Sat Mar 9 2019
Forecasted rainfall still looks to average between 0.5 and 1.00
inch today into this evening. This rainfall falling over a
saturated and frozen ground will runoff fairly quickly into area
waterways. Additional runoff in the form of snow melt will also
occur while temperatures are above freezing.
Another storm system is forecast to affect the Midwest around the
middle of next week. Rainfall and temperatures above freezing
will result in another round of rises on area waterways that may
push additional rivers into flood.
Rock river:
The forecast rainfall and expected snow melt will now push the
Rock river into moderate flood. Additional rises are expected
with the next round of rain late next week that is expected to
push the river even higher.
The situation with the ice jams between Lyndon and Prophetstown
has not changed over the past 24 hours. Route 78 remains open but
water is at the edges of the pavement. Rainfall and temperatures
above freezing may cause water levels near the ice jams to
fluctuate rapidly.
Iowa river:
New flood watches were issued for the Marengo and Lone Tree areas.
The river will rise in response to the rain and snow melt that
occurs today but will remain below flood stage. The next round of
rain and snow melt next week will cause the river to rise again that
may push it above flood stage.
Pecatonica river:
A flood watch was issued for the Pecatonica area. The river will
rise in response to rain and snow melt today but is expected to
remain below flood stage. The next round of rain and snow melt
next week will cause the river to rise again that may push it into
flood.
Mississippi river:
A flood watch was issued for the Gregory Landing area. Two rounds
of rises will occur in response to rainfall and snow melt over the
next 7 days that may push the river into flood.
&&
.CLIMATE...
ISSUED AT 311 PM CST Sat Mar 9 2019
Week 2...March 17-23
Odds favor below normal temperatures and below normal
precipitation in this time frame. Below normal temps will help
ensure the snowpack in Minnesota/Wisconsin does not melt too quickly.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Wind Advisory until 7 AM CDT Sunday for Benton-Buchanan-Cedar-
Clinton-Delaware-Dubuque-Jackson-Jones-Linn-Scott.
Wind Advisory until 7 AM CDT Sunday for Des Moines-Henry IA-
Jefferson-Lee-Van Buren.
Wind Advisory until 7 AM CDT Sunday for Iowa-Johnson-Keokuk-
Louisa-Muscatine-Washington.
IL...Wind Advisory until 7 AM CDT Sunday for Bureau-Carroll-Henry IL-
Jo Daviess-Putnam-Rock Island-Stephenson-Whiteside.
Wind Advisory until 7 AM CDT Sunday for Hancock-Henderson-
McDonough-Warren.
Wind Advisory until 7 AM CDT Sunday for Mercer.
MO...Wind Advisory until 7 AM CDT Sunday for Clark-Scotland.
&&
$$
UPDATE...Speck
SYNOPSIS...Sheets
SHORT TERM...08
LONG TERM...08
AVIATION...Speck
HYDROLOGY...08
CLIMATE...Wolf
Area Forecast Discussion
National Weather Service Grand Forks ND
941 PM CST Sat Mar 9 2019
.UPDATE...
Issued at 938 PM CST Sat Mar 9 2019
Main 500 mb short wave is lifting into northern Wisconsin with
snow ending from the south thru southern MN and snow ending slowly
from the east thru the Red River valley. This trend to continue
with the heavier snow shifting to our far eastern fcst area which
hasnt had as much as farther west. At least that is the forecast
and right now see no reason to alter the messaging of this. Though
it would appear Bemidji/Park Rapids area will see the lower end of
the 8-12 range vs the higher end of the range farther west.
Winds are not playing a factor in NE ND and in the advsisory area
where snow is now all moved out will drop advisory. Will leave
warning as is, though likely a good portion can be expired early
toward morning. Some wind gusts 35 mph or so southern RRV but even
that isnt affecting vsby once snow ends as snow is quite wet and
needs a lot more wind to blow it or drift it.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 344 PM CST Sat Mar 9 2019
Negatively tilted mid/upper level trough axis just west of our CWA
with small mid level circulation apparent near our southern CWA. RAP
analysis showing axis of strong 700MB frontogensis orientated
northeast to southwest across the Red River Valley along with axis
of negative EPVg. This matches radar trends which show
narrowing/intensifying snow band and we should see an uptick in snow
rates. This also matches expected trend reflected in high res
guidance, and while residence time of this band is more uncertain
further north, we should still see potential for additional 3-7" or
within the RRV (totals 6-10"). Further east stronger moisture
advection in axis of WAA continues to rotate north and this will
result in more accumulations there before this band moves eastward.
This allows for possible 8-12" totals for parts of west
central/northwest MN depending again on residence time of band.
Model mixed layer winds still support potential gusts to 35 mph,
though with wet snow there are still questions to how much impacts
there will be if this period of wind occurs after snow ends. Before
wind increases this evening, most significant vis restrictions will
be due to heavy snow alone (some locations reported 1/4sm or less
already). Still, blowing/drifting remain possible this
evening/overnight before gusts start to decrease after midnight.
Regarding headlines: no changes made as most intense period of this
system for our CWA is getting underway. Any adjustments will be
delayed until this evening when we see how this band evolves and
begins to transition east of the RRV. Still expect our western CWA
to see more improvement this evening and if blowing snow is less
of an issue products could be ended this evening.
.LONG TERM...(Sunday night through Saturday)
Issued at 344 PM CST Sat Mar 9 2019
For Sunday night through Tuesday, a quiet period occurs as warmer,
seasonal air builds into the Northern Plains as split flow aloft
merges into upper level ridging over the central U.S.
For Tuesday through early Wednesday, strong warm air advection
over portions of the Northern and Central
Plains coupled with a weak shortwave aloft will induce precipitation
chances across portions of the area. Model forecast soundings
suggest potential for freezing rain and/or drizzle as a strong low
level warm nose develops Monday night into Tuesday morning. In this
period, QPF is likely to be less than a tenth of an inch with the
best chances for precipitation in northwest MN and possibly little
to no precipitation west of the RRV. As surface temperatures
increase through Tuesday, precipitation is expected to gradually
transition to rain.
Of greater concern is widespread precipitation chances building
across the Northern and Central Plains Wednesday afternoon through
Thursday as a strong Colorado low tracks from western Kansas to the
Great Lakes region. This system looks to bring a wet period with
around a half inch to inch of QPF across southeast ND
and the northwest quarter of MN and a much greater uncertainty
in amounts for areas further north and west. At this point, the most
likely scenario is an initial predominant cold rain period as
temperatures remain near or above the freezing mark and a transition
to snow occurring Wednesday night or Thursday. A strong surface
pressure gradient behind this system coupled with mixing an
anomalously strong 850mb jet streak yields potential for blowing
snow Thursday and perhaps Thursday night. However, with temperatures
hovering around the freezing mark, there is low confidence in any
details regarding precipitation type and amounts at any given
location at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 708 PM CST Sat Mar 9 2019
IFR conditions in vsby in snow for all but DVL basin this evening
with improving conditions slowly into GFK by 06z and then rest of
the area later tonight/Sunday AM. Once snow ends ceilings will
rise and expect VFR balance of Sunday daytime.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Winter Storm Warning until 1 PM CDT Sunday for NDZ027>030-038-
039-049-052-053.
MN...Winter Storm Warning until 1 PM CDT Sunday for MNZ001>003-005-
006-008-009-013>017-022>024-027>032-040.
&&
$$
UPDATE...Riddle
SHORT TERM...DJR
LONG TERM...BP
AVIATION...Riddle
Area Forecast Discussion...UPDATED
National Weather Service Green Bay WI
820 PM CST Sat Mar 9 2019
New Information added to update section
.UPDATE...
Issued at 809 PM CST Sat Mar 9 2019
No headline changes planned this evening, though will be
reshuffling the zone configuration a bit in the next WSW update.
The primary band of precipitation with the cyclone tracking into
the region continued to lift north across the forecast area.
After an hour or so of mixed precipitation across the southern two
tiers of counties in the area, the precipitation changed to snow
due to evaporative cooling. Some very heavy snow has occurred,
with a Co-op observer in Plover reporting nearly 2.5 inches of
snow in an hour.
The primary band will continue to shift north, and northern
Wisconsin is cold enough for all snow with any precipitation of
consequence. Strong forcing is still present in the wake of the
primary band, so expect additional development to occur and feed
into the southern portion of the band. But the new development is
unlikely to reach the intensity of precipitation with the main
band. Which is fortunate for the going forecast, because it would
not take too long to sail right past forecast snow amounts if the
high snowfall rates were to persist for too long.
Satellite indicates some mid-level drying behind the primary
band, so it is possible precip could change to FZDZ during lulls.
Will refresh the hourly grids and forecast shortly, but the gist
of the going forecast remains on track.
UPDATE
Issued at 542 PM CST Sat Mar 9 2019
The main surge of precipitation associated with a mature cyclone
tracking northeast from the Central Plains has reached the area.
The air at low levels was very dry, with surface dew point
temperatures around 20F and the zero-degree (C) maximum wet-bulb
temperature aloft isotherm completely south of the area on local
meso plots. This indicates there will be significant evaporative
cooling with the onset of precipitation, likely causing a
transition to heavy snow across much of central and east-central
Wisconsin within an hour or so after precipitation begins. There
may be a tendency to flop back to more of a mix once the heaviest
radar returns shift through. Have handled with with an SPS, and
will re-evaluate snow totals for this area shortly.
&&
.SHORT TERM...Tonight and Sunday
Issued at 234 PM CST Sat Mar 9 2019
The latest RAP analysis and satellite/radar imagery show a potent
area of low pressure centered over northeast Kansas early this
afternoon, while high pressure prevails along the east coast of
the conus. A wide arcing band of precipitation is lifting
northeast across Minnesota through Illinois, and starting to work
into southwest Wisconsin. Ample dry air emanating out of the
departing high have slowed down the precip slightly, and the
latest short range models show the precip starting to move into
central WI and the southern Fox Valley in the 4-5 pm time frame.
Precip continues to look like a mix at arrival time due to the
below freezing surface wet bulb temps and warmer air pushing in
aloft. As the low swings northeast tonight, forecast concerns
revolve around potential snow and ice accumulations.
Tonight...Low pressure remains on track to move northeast across
northern Illinois and into northern Lower Michigan. The strongest
forcing will push across the area during the evening, via a 50kt
low level jet and associated moisture transport, mid-level fgen,
and dpva ahead of the shortwave. As a result, should see most of
the precip occur during the evening, though comma head precip
should continue through the rest of the night. Models continue to
indicate that the surge of warm air aloft only grazes east-central
WI for a couple hours during the evening. Progged soundings also
indicate that moisture above the -10C temp line will also be lost
at times over parts of central and northeast WI this evening. The
combo of warm air aloft and loss of ice crystals continue to
suggest some ice/sleet accumulations roughly south of a line from
Mosinee to the tip of the Door Peninsula, most likely highest over
east-central WI. This will eat into the potential snow
accumulations somewhat in this area. In general though, 3-6 inches
of snow accumulations is a solid bet across most of the area,
except for 1-3 inches over parts of east-central WI. Despite gusty
east to north winds, the heavy/wet nature of the snow should
limit blowing and drifting somewhat. No adjustments to the
inherited advisory look necessary even with the slower timing, as
start times line up with surrounding offices, and the potential
ice accumulations continues to justify an advisory for east-
central WI.
Sunday...Low pressure will continue to lift away from the region
into northeast Ontario. Light comma head snowfall will likely
continue for most of the area early in the morning before ending
from south to north through midday or early afternoon. Additional
accumulations could reach up to an inch across far northern WI,
but most likely will remain under an inch. Cloudy and windy
conditions should then persist through the rest of the day. Gusts
up to 35 mph will be possible, which could lead to some blowing
and drifting of the lighter weight snowfall, especially over
northern WI where the higher snow to liquid ratios will occur.
Highs ranging from the low to mid 30s over most of the area.
.LONG TERM...Sunday Night Through Saturday
Issued at 234 PM CST Sat Mar 9 2019
The main concern in the extended portion of the forecast will be the
potential rainfall/flooding potential for the middle of the workweek
along with above normal temperatures.
Sunday night through Tuesday: A surface ridge and increasing 500mb
heights will be in place through this time period, bringing an
extended break in the precipitation along with warmer temperatures.
In fact many places will warm to near normal by Tuesday afternoon.
Highs Monday will be around 30 while high temps warm to the mid and
upper 30s for Tuesday. Overnight lows will be chilly with lows
dropping down into the teens Sunday night and to the single digits
above and below zero for Monday night. Leaned toward the colder
guidance for Monday night with high pressure over the area, clear
skies and PWAT values around 25 percent of normal.
Wednesday through Thursday: The next southern stream piece of energy
is expected to eject out of the Four Corners region into the central
Plains Tuesday night into Wednesday morning. This would likely
lead to rapid cyclogenesis across the Oklahoma and Texas Panhandles
Wednesday morning. The low is then expected to lift northeastward,
reaching western or central WI late in the day Thursday. This would
keep most of the CWA in the warm sector, keeping the precipitation
mainly in the form of rain. There could be a brief period of mixed
precipitation early Tuesday evening, but this should quickly
transition to all rain for the rest of this time period. Of greatest
concern will be how much rain falls out of this system as it
traverses the area. It looks like there will be plenty of moisture
for the system to work with as the surface isobars remain wide open
to Gulf moisture through much of this time period. PWAT values are
progged to be around 1.0 to 1.5 inches for this time period, which
is roughly 200 percent of normal for this time of year. A strong
southerly LLJ is progged to develop ahead of this system, which will
allow moisture to quickly advect northward into the CWA along with
much warmer temperatures. Actually, most of the models are pushing
850mb temperatures up to around the +6 to +10C range Wednesday into
Wednesday night. This would allow temperatures to warm well above
freezing through this time period with most locations warming well
into the 40s and possibly even pushing 50 in a few locations. The
combination of increasing dewpoint temperatures (above freezing/mid
to upper 30s) and warmer temperatures will start melting some of the
snow across the area; however, this will take some time as the
snowpack is fairly dense and will take time to ripen to the point
where rapid melt would take place. The bigger concern will be
largely focused on the potential for an inch or so of rain to fall
(GEM/GFS) on frozen ground and across areas that may have poor
drainage due to ice/snow clogging. The latest 12Z model run of the
EC has less QPF, closer to a half inch or so. There will of course
be some contribution from melting snow, but the bigger issue will
likely be any significant amount of rain that falls, which may lead
to at least localized flooding concerns.
Rest of the extended: A cold front will then pass through the area
ushering much colder air and a fairly deep upper-level trough for
Friday. This will effectively put the brakes on any snow melt issues
and help to lock in any water making its way through the snowpack.
Otherwise, temperatures will fall back well below normal with highs
only expected to reach into the upper 20s and low 30s for Friday
into Saturday.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 542 PM CST Sat Mar 9 2019
A band of heavy precipitation in the northern quadrant of a mature
cyclone tracking northeast from the Central Plains will push
across the area this evening, taking aviation conditions down to
IFR/LIFR. LLWS is also likely this evening as winds aloft increase
with the approach of the storm.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 10 AM CDT Sunday for WIZ022-031-
035>040-045-048>050-074.
Winter Weather Advisory until 1 PM CDT Sunday for WIZ005-010>013-
018>021-030-073.
&&
$$
UPDATE.........Skowronski
SHORT TERM.....MPC
LONG TERM......Cooley
AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Grand Rapids MI
1037 PM EST Sat Mar 9 2019
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 300 PM EST Sat Mar 9 2019
- Freezing rain central lower Michigan this evening
- Windy late this afternoon through tonight into Sunday
- Some light snow showers late tonight and Sunday
- Milder with rain showers Wednesday through Thursday
&&
.UPDATE...
Issued at 1022 PM EST Sat Mar 9 2019
Based on recent trends in wind and weather we added Oceana and
Mason. A variety of precipitation types along with gusts over 40
knots support the headline. Some impacts also noted on the roads.
UPDATE Issued at 843 PM EST Sat Mar 9 2019
We added a few more counties to the winter weather advisory. This
was based on temperatures being at or below freezing and rounds of
precipitation moving through. Radar does show another round of
steady to heavy precipitation tracking towards these counties...so
conditions will likely worsen over the next hour or two.
We have been highlighting the wind impacts much of the evening.
Gusts have generally been 35 to 45 throughout the area and this
has caused some power outages. It looks like there will be a lull
in the wind starting in an hr or two the will last for a few
hours. Then the wind will shift to the southwest and increase
considerably again after midnight. Winds of 35 to 45 mph are
expected. Thus...scattered power outages are possible again late
tonight into Sunday.
&&
.DISCUSSION...(This evening through next Saturday)
Issued at 300 PM EST Sat Mar 9 2019
Main short term fcst concerns continue to involve assessment of
freezing rain potential north of I-96 this evening.
A strong low pressure system near Kansas City early this afternoon
will move northeast and bring rain into our southern fcst area
late this afternoon and evening. A consensus of latest high
resolution model guidance such as the nam nest and hrrr continue
to show potential for several hours of freezing rain over roughly
the northeast 6 counties in our fcst area where the winter wx
advisory is in effect.
The winter wx advisory headline looks excellent and will remain
unchanged for up to around a tenth of an inch of ice accumulation
up there. Latest hrrr and especially the 12z nam nest guidance
still show potential for more ice accumulation than that. However
based on overall shorter range guidance trends the past 24 hours
we believe a tenth of an inch or less of ice accumulation will be
the most likely outcome up there and this notion is more in line
with latest runs of the hrrr.
12Z HREF ensembles suggest pcpn could even begin as fzra as far
south as KMKG/KGRR/KLAN. Based on overall guidance trends and
current sfc obs this is too far south (unless if wet bulb/dynamical
cooling effects when rain initially moves in this evening causes
the sfc temp to drop to 32 F). It is noted that dew point values
along the I-96 corridor are only in the teens as of mid aftn. Our
gut feel is that sfc temps will stay above freezing in the middle
30s in the GR metro area this evening before actually going up a
few degrees late tonight before fropa.
This strong low pressure system will bring windy conditions late this
afternoon through tonight into Sunday. Peak wind gusts may flirt
with advisory criteria at a few locations (especially near the
Lake MI shoreline) this evening and overnight. However for the
most part we expect gusts predominantly in the 30 to 44 mph range.
Therefore we will not issue a wind advisory headline.
Rain showers will change over to snow showers late tonight as caa
commences on the back side of the low. However any snow
accumulations late tonight through tomorrow will be very light at
only around an inch or less (relatively highest accumulations in
that range over our northern fcst area).
Tranquil wx is fcst Monday through Tuesday as a high pressure ridge
builds in from the west. Strong waa will develop on the back side
of the departing ridge for midweek and rain showers are forecast
Wednesday through Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 636 PM EST Sat Mar 9 2019
Gusty wind impacts will continue at the TAF sites for much of the
period with values topping 30 knots at times with local 40 knots
possible. The direction will be shifting from east to southeast
then southwest to more of a westerly wind through the period as
well. Visibility and ceiling impacts are likely as well with
moisture on the increase and rain moving in. The onset of the
precipitation is close to being a wintry mix...but at this time it
looks like it will be plain rain for the TAF sites. IFR is
expected at times with an increased risk for sub IFR. Some
instability lifting northeastward from Indiana may support an
isolated thunderstorm or two...mainly over far southern Lower
Michigan this evening.
As temperatures fall late tonight into Sunday morning any
remaining precipitation is expected to transition into snow.
&&
.HYDROLOGY...
Issued at 300 PM EST Sat Mar 9 2019
Rain and freezing rain will spread into the area this evening and
last through the overnight hours before changing to light snow
Sunday morning. Total rain and water equivalent from the ice and
snow that will fall looks to average around three-quarters of an
inch. Rain may even be heavy at times. Rain and warmer temperatures
will melt some of the snowpack, especially for areas near and south
of I-96. Runoff from precipitation and snowmelt will cause
significant rises on rivers and streams, starting with the smaller
ones this weekend, with the larger rivers following next next week.
The most notable rises are expected to occur within the Grand River
Basin, and many rivers and streams there are forecast to reach
bankfull. A few could just touch minor flood stage (Looking Glass
near Eagle, Grand River near Robinson Township) and will need to be
watched closely.
Additional precipitation is expected Wednesday night and Thursday,
but has not yet been accounted for in current river forecasts.
Although amounts look much lighter with this second system, much
warmer temperatures are expected which will melt much, and in some
places all, of the snow left on the ground. This could prolong or
add to rises in rivers already occuring due to precipitation this
weekend.
Finally, ice remains intact along stretches of rivers in West
Michigan. Warmer temperatures and increased runoff may shift or
break this ice up, leading to rapid changes in water levels or even
a few break-up ice jams. If you live along a river, be alert for
changing conditions and rising water levels.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 1 AM EST Sunday for MIZ037>040-
043>046-051-052.
&&
$$
UPDATE...MJS
SYNOPSIS...Laurens
DISCUSSION...Laurens
AVIATION...MJS
HYDROLOGY...HLO
Area Forecast Discussion
National Weather Service Jacksonville FL
858 PM EST Sat Mar 9 2019
.UPDATE...
Warm southerly flow continues over the forecast area this evening
with fairly strong low pressure system at 991 mb over IL with
trailing cold front through the Mid MS valley into ern TX.
Locally, temps are in the 60s and 70s at 8 pm and with occasional
clouds tonight and with prevailing low level flow from the south,
lows not expected to drop lower than about 58-60 deg tonight.
Some patchy fog is possible but given the low level weak boundary
layer mixing and occasional clouds, not the optimal setup for
some fog formation. Some stratus and fog may form near the coast
where relatively warm/moist air overrides the cooler Atlantic
shelf waters, so will maintain patchy fog and some stratus for the
coastal areas overnight and into Sunday morning. Otherwise,
little change for the evening update.
&&
.AVIATION...
VFR cig conditions will prevail most of tonight and Sunday. A
brief period of MVFR cig/vsby possible from 06z to 13z. HRRR and
SREF also suggest some lower cig conditions to IFR/LIFR at SSI
late tonight and early Sunday due to some potential for sea fog
off the Atlantic waters, so will be monitored. Stratus and any
mist/fog will dissipate Sunday morning with VFR conditions after
13z-15z.
&&
.MARINE...
South-Southeast winds near 10-15 kt will gradually veer to south
and decreasing a few knots by 12z Sunday. The increased winds may
kick up wind waves a bit for tonight. A slight decrease in winds
around 12z may enable some patchy sea fog to form along the coast
by early Sunday morning. Will keep this in the forecast at this
time.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 61 83 62 78 / 0 20 30 20
SSI 62 77 62 75 / 0 0 20 20
JAX 63 83 62 81 / 0 0 10 40
SGJ 65 81 62 80 / 0 0 10 30
GNV 63 85 61 84 / 0 0 0 30
OCF 63 85 61 85 / 10 0 0 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Shashy/Peterson
Area Forecast Discussion
National Weather Service Elko NV
202 PM PST Sat Mar 9 2019
.SYNOPSIS...
A storm system will bring accumulating snow to parts of central
Nevada tonight through Sunday but should stay mainly south of
Interstate 80. Snow showers will taper off Sunday night as the
weather disturbance moves farther away from the region. Another
cold front will bring more snow to the state Tuesday into
Wednesday before drier conditions finally settle in for the
latter part of the week.
&&
.SHORT TERM...Tonight through Tuesday. Mid-level low pressure
system will slide southeastward along the CA coast through Sunday.
A diffuse boundary across central Nevada along with the CA low
will regenerate snow across central Nevada tonight into Sunday.
Central Nevada including southern Lander and Eureka counties, far
northern Nye county and White Pine county are still expected to
see advisory level snowfall. 3 to 5 inches should be common in
WHite Pine County with slightly lesser amounts further west. In
addition, the northern extent of the snow band has trended
northward closer to I-80 in the latest mesoscale model runs. The
HRRR, NAM and RAP all show another round of snow reaching into
southwest Elko Sunday morning. Although more snow is expected
across southern ELko county, only about an inch is anticipated
through the late morning hours before snow diminishes along the
I-80 corridor. As the low pivots into Baja California,
precipitation will diminish and dissipate across central NV
Sunday night and Monday. Monday night into Tuesday morning still
appear dry with yet another cold front and trough moving through
the state Tuesday and Tuesday night.
.LONG TERM...Tuesday night through next Saturday.
Cold front continues to make its way through Nevada on Tuesday
night and will be east of the area by Wednesday morning. 1-3
inches of snow may fall in the valleys and the mountains of
northern Elko County could see 4-8 inches by the time the storm
exits. Breezy to windy northwest winds immediately follow the
front as a longwave trof digs into the central U.S. and gradients
tighten in our area. The winds will continue into Wednesday
before diminishing on Wednesday night. Otherwise, there will just
be some leftover snow showers hanging around through Wednesday
evening.
We will then likely transition into a cool and dry northerly flow
through at least Thursday. Ridging then attempts to build in
starting Friday, ushering in a long awaited period of drier
weather along with a warming trend.
&&
.AVIATION...Scattered snow showers continue in northern and
central Nevada through the evening, but for the most part VFR
conditions should hold at all stations through tonight. The
exception will be at KELY, where a period of snow showers could
bring some tempo IFR conditions later this evening. Steadier snow
is expected to arrive there early Sunday morning and KTPH will
also see some showers begin early in the morning.
NOTE: KELY is AMD NOT SKED due to problems with visibility and
weather sensors.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 11 PM PDT Sunday for White Pine
County.
Winter Weather Advisory from 10 PM PST this evening to 11 PM PDT
Sunday for Northeastern Nye County-Northwestern Nye County-
Southern Lander County and Southern Eureka County.
&&
$$
93/90/90
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
851 PM CST Sat Mar 9 2019
.UPDATE...
851 PM CST
Have expanded the wind advisory across to include the northern
tier of counties as well. RAP, NMM, and HRRR bufkit soundings
overnight show winds as strong, if not stronger, for KRFD as
points farther south in the advisory. Over the past couple hours
the number of advisory level gusts at upstream sites has
decreased, but still seeing occasional gusts to advisory level.
Certainly would expect 40 mph gusts CWA wide overnight with at
least scattered sporadic gusts of 45+ mph.
- Izzi
&&
.SHORT TERM...
212 PM CST
Through Sunday...
Mild, wet, and breezy conditions are expected through the rest of
today, then conditions will turn windy and colder Sunday. Early this
afternoon, a 992mb low is analyzed east of Kansas City with a
warm front draped east across central Illinois and along portions
of the Ohio Valley. Meanwhile, water vapor imagery reveals a
negatively tilted trough lifting across northern Missouri. These
features are progged to lift northeast across northern Illinois
this evening. Rain, along with a few embedded thunderstorms, have
already overspread much of the forecast area this afternoon.
Periods of steady rain, at times moderate to heavy, will persist
well into the evening until the warm front begins to lift across
the region. Loss of deeper moisture should allow precip to taper
off with a few spotty showers possible behind the warm front.
Center of low pressure is expected to lift into far southeast
Wisconsin late this evening, then continue northeast across the
central Great Lakes region overnight. While precip chances diminish
in the wake of the low, winds are expected to swing around to the
west and further increase overnight. The combination of a strong
pressure gradient, steep low level lapse rates driven by cold air
advection, and moderately strong surface pressure rises sweeping
across the forecast area will result in wind gusts right around
advisory criteria of 45 mph. Both the GFS and NAM advertise 5-
7mb/3hr pressure rises moving across the CWA overnight, though
weakening as it spreads east. Will be issuing a Wind Advisory
through Sunday morning for all but the far northern tier of
counties in Illinois, closest to the low track where the gradient
is not quite as strong.
Breezy conditions will persist through the day Sunday, though should
very gradually taper in magnitude as high pressure spreads from the
northern Great Plains to the Ohio Valley. Persistent cold advection
will only allow temperatures to recover a few degrees Sunday
afternoon with highs in the mid to upper 30s expected over most of
the CWA. Shallow post frontal cold air stratocumulus will keep skies
mostly cloudy through the day, with some clearing possible during
the evening. Temperatures are expected to fall into the low to mid
20s Sunday night with wind chills in the single digits and teens.
Deubelbeiss
&&
.LONG TERM...
116 PM CST
Sunday night through Saturday...
High pressure will usher a frontal trough Sunday night. There is a
weak disturbance in northwest flow aloft that still looks just
produce some clouds when it arrives Sunday night into early
Monday.
The surface high will arrive Monday into Tuesday, leading to a
period of dry but cool weather. The high will shift east of
the area late Tuesday and again open the door to another amplified
pacific system emanating from the southwest. Deep layer flow will
become markedly southerly ahead of the highly meridional flow
across the Midwest and eastern portions of the United States as,
at least for a time, several systems merge into a large scale
trough across the western half of the country. With upstream
ridging in place, the model evolution becomes a bit more tricky as
to how quickly precipitation will push into the departing ridge.
But it appears the fairly wound up lead system will send several
shortwaves ahead of it and lead to mild, windy, and occasionally
wet periods later Tuesday into Thursday.
The main surface low will approach the region Thursday into
Friday, weakening as it will move from the Mississippi valley to
northern Lake Michigan. With this pattern, it appears we get
somewhat split with the system dry slot possibly moving right
overhead and the heavier precip will head south. With the dry slot
moving in and warm southerly flow, temperatures could briefly get
quite mild Thursday morning The northern stream flow will
eventually win out late week, sending a cold front through
Thursday afternoon/evening and possibly even leading to some snow
showers.
KMD
&&
.AVIATION...
For the 00Z TAFs...
The main forecast concerns through the period are:
1.) the threat of a few embedded thunderstorms through around 01z
over the eastern terminals.
2.) CIG and VSBY trends through the evening, with IFR conditions
likely, possibly lowest at KRFD.
3.) Strong gusty easterly winds this evening, with veering winds
this evening before becoming very gusty from the west overnight and
continuing on Sunday.
A potent area of low pressure will track northeastward across
north central IL early this evening before shifting into Lower
Michigan overnight. Periods of showers, with a few embedded storms
will be possible this evening, with the primary thunder threat
just through 01z. Also expect gusty easterly winds to gradually
swing to the south-southeast mid to late this evening.
Visibilities will be down into the 1-2 mile range, especially
early this evening. However, with the track of the surface low
going right over the RFD area, they could experience a short 1 to
3 hour period of low visibilities down around 1/2 a mile before
the low shifts to the northeast.
Overnight, expect strong west-southwesterly winds to develop,
especially after 06-07z. A period of gusts up to around 40 kt is
possible with the initial onset of the westerly winds. However,
wind gusts may begin to settle down to around 30 kt during the day
on Sunday.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Wind Advisory...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 until 7 AM Sunday.
IN...Wind Advisory...INZ001-INZ002-INZ010-INZ011-INZ019 until 7 AM
Sunday.
LM...Gale Warning...nearshore waters until 4
PM Sunday.
Small Craft Advisory...nearshore waters
until 11 PM Saturday.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1016 PM EST Sat Mar 9 2019
.SYNOPSIS...
A warm front will lift north through the area tonight. A cold
front will approach from the west Sunday and cross the area
Sunday night. High pressure will build in from the northwest
early next week and slide offshore by mid week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1010 PM Saturday...The warm frontal boundary continue to
lift north and is approaching our south coast at late evening as
high pressure off the northern New England coast slowly retreats
offshore. Some light showers are offshore with additional
showers well north and west of the CWA. The latest HRRR and 3km
NAM continue to trend fairly dry overnight and will keep the
existing low PoPs in the forecast overnight to account for some
light showers that could sneak into the area from off the water
or from the west. Temperatures have likely reached their low for
the night and should start to slowly rise as the warm front
lifts north. No major changes made to the current forecast.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
As of 2 PM Sat...Deep low pressure will continue to lift
through the Great Lakes region as attendant cold front
approaches Eastern NC from the west. Eastern NC will be in the
warm sector and SPC continues to outlook most of the area in a
Marginal Risk for severe weather. 12z guidance has continued to
trend like previous guidance depicting a drier solution across
the area. Latest global, high res and ensemble guidance show
pretty good instability (MU CAPE values around 1000 J/kg)
developing across the area Sun afternoon and bulk shear 30-40
kt. Best forcing will remain north of the area but could be just
enough convergence combined with instability to generate
scattered convection. At this point moisture looks like the only
limiting factor. Some strong to severe storms with gusty to
possibly damaging winds will be possible during the afternoon
and evening hours.
Very warm day expected with temps well above normal despite the
cloud cover. Low level thickness values and SW flow support
highs in the upper 60s to low 70s along the coast, and mid to
upper 70s inland. Some guidance shows the potential for sea fog
developing during the day, but feel this is likely overdone at
this point but not out of the question.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
As of 310 PM Sat...The front will gradually push offshore with
lingering showers Monday morning before conditions dry out as
high pressure dominates the region. Another cold front is
expected to approach the area at the end of the work week.
Sunday night through Monday...As the cold front approaches ENC,
upper level support becomes marginally better behind the front
as a subtle shortwave approaches during the overnight hours.
This will allow for shower coverage and intensity to increase
Sunday night. Gradually increased PoPs to high chance/likely
for the tidewater and coastal zones with the highest chances
between 00-06Z. Any severe threat will be diminished by this
point but with lingering marginal instability kept the mention
of isolated thunderstorms through 06z Monday; mostly along the
coastal areas. The front is forecast to be offshore by Monday
morning with a few lingering showers possible along the southern
coast. High pressure will build in from the NW...providing
drier conditions by Monday afternoon. Highs Monday around the
mid to upper 60s with lows falling into the low 40s as a dry
front pushes across Monday night.
Tuesday to Friday...Upper level ridging gradually amplifies into
Thursday with high pressure dominating through most of this
period. Temperatures will slightly be below normal Tuesday and
Wednesday with highs upper 40s NE to around 60 SW. Highs climb
back into the 60s NE to around 70 SW Thursday and then low to
mid 70s as southerly flow ahead of another approaching cold
front. The 12Z GFS/ECMWF are in decent agreement regarding
timing of FROPA and precipitation but will go no higher than
chance PoPs for now.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Short Term /through 00Z Monday/...
As of 7 PM Saturday...With the exception of some lower ceilings
around KPGV, TAF sites are currently in the VFR range. Tricky
forecast for this TAF cycle. Most guidance shows a period of
solid MVFR ceilings for all TAF sites after midnight and will
follow this trend, however lack of any precipitation to moisten
the low-levels may prevent ceilings from lowering quite as
dramatically as guidance is showing. Any low ceilings should
lift after 13z-14z as mixing improves with warm front moving
north of the area. Most of the high-resolution models show the
bulk of any showers or psbl tstms holding off until after 00z
and have left shower/tstm mention out of the TAFs at this time.
Long Term /Sunday night through Thursday/...
As of 305 PM Sat...Sub-VFR conditions may linger through Monday
morning before VFR conditions return by afternoon. VFR
conditions will dominate through Thursday.
&&
.MARINE...
Short Term /through Sunday/...
As of 1015 PM Saturday...Winds continue NE/E at 5-15 knots on
area waters at late evening with seas 3-4 feet. The warm front
is starting to move into the far southern waters and will
continue to lift north overnight. As a result, winds become SE/S
10-20 kt late tonight and early Sun. The warm front will be
north of the waters by Sunday morning as cold front approaches
from the west during the day. SW winds will increase to 15-25 kt
Sun. Went ahead with a SCA for the waters south of Oregon Inlet
and the Pamlico Sound for the increasing SW winds developing
ahead of the front Sunday afternoon into Sunday night. Seas will
build to 4-6 ft late Sun afternoon and evening.
Long Term /Sunday night through Thursday/...
As of 305 PM Sat...Conditions are expected to improve Monday
after the cold front pushes through the coastal waters with seas
diminishing to 3-4 feet and winds becoming NW/N at 10 knots or
less. A dry cold front pushes through late Monday into Tuesday
with N wind increasing to 15-20 knots with possible gusts to 25
knots and seas 4-6 feet especially for nrn and cntrl waters.
Seas are expected to subside subside to 2-4 feet Wednesday and
Thursday as winds diminish to 10-15 knots from the NE/ENE, then
veering to the S Thursday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 2 PM Sunday to 2 AM EDT Monday for
AMZ152-154.
Small Craft Advisory from 2 PM to 11 PM EDT Sunday for AMZ135-
156-158.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...BM/MS
AVIATION...CTC/CQD/MS
MARINE...CTC/CQD/MS
Area Forecast Discussion
National Weather Service Marquette MI
633 PM EST Sat Mar 9 2019
.SHORT TERM...(This evening through Sunday)
Issued at 424 PM EST SAT MAR 9 2019
Water vapor imagery and RAP analysis show a vigorous, negatively
tilted shortwave lifting ne into the Mid-Mississippi Valley this
aftn. Diffluent flow aloft, strong dynamics and abundant moisture
(precipitable water running up to 200-250pct of normal thru the
southern/central Plains per 12z raobs) are supporting a large swath
of pcpn up the Mississippi Valley into the Ohio Valley. Pcpn is
spread across sw WI as of 21z. At the sfc, 990mb sfc low was located
over nw MO.
Shortwave will swing ne into the western Great Lakes region by 12z
Sun and then continue into Ontario during the day as it weakens.
Strong isentropic ascent/deep layer forcing/upper diffluence will
quickly spread ne across the area tonight, but strongest forcing is
fcst to occur to the s and sw of Upper MI with a weakening trend
evident as the forcing lifts ne into the fcst area. As a result,
pcpn is likely to be diminishing in intensity as it moves across
Upper MI. There is still some potential of mid-level dry slotting to
occur late tonight/Sun morning over the se/e fcst area, but there is
not a solid signal in all the guidance. Opted to maintain previous
fcst mention of chc -fzra in that area due to the potential of a
reduction in ice nuclei from the dry slotting. Mixing ratios of 3-
4g/kg are available per 290-295k sfcs (roughly 700-750mb),
suggesting snowfall of 3-4in/6hr, which is about how long the
isentropic ascent portion of the event lasts tonight. Cyclonic n
backing nw low-level flow and lingering deep layer forcing Sun
morning will support some additional snowfall during the morning,
especially across the higher terrain of western and northern Upper
MI favored by the backing, upslope winds. 850mb temps around -8C on
Sun are marginally cold enough for lake enhancement, but
considerable ice cover on Lake Superior will significantly diminish
the lake enhanced component to the snowfall over what it could be.
Lingering snow across the w and n will diminish Sun aftn. However,
another shortwave will streak from the Dakotas to nw WI by 00z Mon.
This wave should give a boost to the snow over the w during the
latter portion of the aftn. Winds will become gusty out the nw to w
during the day on Sun as the low departs. Weak CAA and a lack of an
isallobaric component to the wind will help to keep winds in check.
Still, expect gusts to 25-35mph Sun aftn, leading to some drsn/blsn.
As for snow amounts, should see a widespread 3-5in snowfall across
the area by late Sun morning with a few spots perhaps reaching 6in.
Boosted by an upslope e backing ne wind overnight, the high terrain
of Marquette County w of Marquette probably has the best potential
of seeing amounts up around 6in. During Sun aftn, another 1-2 inches
of snow may accumulate e of Munising and also over western Upper MI.
Fcst snow amounts are still blo the low snow-to-water ratio snowfall
criteria for a warning (at least 6in/12hr or 8in/24hr), so no
headline changes from current advy are needed. Since this will be a
wet/heavier snow, it will be more difficult to shovel/plow, and of
course, wet snow makes travel conditions more hazardous than high
snow-to-water ratio snow.
.LONG TERM...(Sunday night through Saturday)
Issued at 340 PM EST SAT MAR 9 2019
As a lobe of vorticity and a surface trough move through early Sun
night, could see 1-3" of snow in areas favored by NW wind upslope
(Keweenaw, Huron Mountains, And NE Upper MI). Snow quickly tapers
off by later Sun night. Some blowing snow is expected near Lake
Superior Sun night into Mon.
Attention then turns to Tue night into Thu night when warm, moist
air surges into the region ahead of a strong low pressure system.
Ptype is troublesome Tue night as surface temperatures start out
below freezing, resulting in some freezing rain, but temperatures
will be warming so the threat will not be overly persistent.
Temperatures will top out in the 40s Wed and Thu with lows Wed night
above freezing. Dew points will also be above freezing. Rain is
expected more often than not during the period, with potential for 1-
2" of liquid. Uncertain on exactly how much runoff into streams will
occur, but at this point expecting the snow pack to soak much of
the precip up. Certainly could see some issues with ponding on water
on roads, though.
Precip turns to snow Thu night and Fri as the rapidly weakening low
shifts across the area. Plenty of uncertainty in how much snow
falls, but not looking like anything too significant at this point.
Colder temps Fri into the weekend will, for the most part, put a
halt to the melt, leaving us with even more liquid in the very
compressed snow pack.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 633 PM EST SAT MAR 9 2019
VFR conditions will prevail into the early evening at
KIWD/KCMX/KSAW. Approaching low pres system will then spread snow
from sw to ne tonight. Conditions at all terminals will deteriorate
quickly to at least IFR once the snow begins. A period of LIFR is
certainly possible overnight. Improvement to MVFR should
occur late Sun morning or early aftn.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 424 PM EST SAT MAR 9 2019
Low pres currently over nw MO will track to far eastern Upper MI Sun
morning, and then into Ontario Sun aftn. As it approaches, easterly
winds will increase to 20-30kt across across Lake Superior tonight.
Not out of the question that there could be a few gale force gusts.
On Sun, winds will back around to the nw to w, and gales to 35kt
should develop over the e half of the lake for the aftn into the
early evening. Winds will only slowly diminish from w to e Sun
night/Mon, leading to a period of lighter winds under 20kt Mon
night/Tue. Winds will increase again midweek, but gales are not
anticipated at this time.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory until 5 PM EDT Sunday for MIZ001-003>007-
013-014-084-085.
Winter Weather Advisory until 5 PM EDT /4 PM CDT/ Sunday for
MIZ002-009.
Winter Weather Advisory until 1 PM CDT Sunday for MIZ010>012.
Lake Superior...
Gale Warning from 2 PM to 10 PM EDT Sunday for LSZ248>251-
265>267.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...Titus
AVIATION...Voss
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Reno NV
157 PM PST Sat Mar 9 2019
.SYNOPSIS...
A couple colder storms will impact the region. The first tonight
into Sunday will bring snow showers with light accumulations to
many areas. A second fast moving cold front will bring light snow
and strong winds Tuesday. The balance of the week into the
following week looks dry with gradually warming temperatures,
heralding the much anticipated start of spring in the region.
&&
.DISCUSSION...
Through Monday...
Ah, nothing like another clear cut storm headed our way...
* Low pressure off the N California coastline will bring periods
of snow showers to the Sierra and Western Nevada this evening
through Sunday. Problem is potential for banding/stalling that
could yield bigger snow amounts and impacts in localized areas.
No radical changes to the forecast, just a few tweaks to snow
totals through Sunday.
* Heavily weighted forecast on 12z/18z HRRR which shows most
areas, mountain and valley, getting light snow showers tonight
into Sunday morning. High-res models indicate banded areas of
snow over W Nevada that more or less stall as steering flow
turns from southerly to easterly late tonight. Each run has a
different spot but a few have been over the Reno and Carson City
area, perhaps just to the northeast near Pyramid Lake.
* For the Sierra tonight into Sunday morning, a 8/10 chance of
seeing at least a dusting, with a 6/10 chance of 1-3" in
mountain communities. For Western Nevada, let`s say a 7/10
chance of seeing at least a dusting of snow accumulation tonight
into Sunday morning with a 4/10 chance of ~1" and a 2/10 chance
of 3" or more. Just to convey the confidence a little
differently.
* From an impact standpoint with temperatures expected to fall
below freezing, any new snow will stick to untreated roads. So
even an inch or less could have meaningful travel impacts
overnight into Sunday morning. Predictability with this storm is
low with hit and miss snow amounts. That plus with typical low-
traffic volumes Saturday night into Sunday morning so have
opted to pass on a winter weather advisory.
* Into Sunday afternoon and evening instability driven snow
showers will persist, however with March sun energy and temps
warming above freezing road impacts should be low. Eastern
Sierra probably has their best snow coverage then as low
pressure continues dropping south. Sunday evening has some
concern with models showing snow showers continuing coupled with
cooling temps, so travel impacts may return then.
-Chris
Tuesday Onward...
Other then lowering min temps a few degrees later next week, we
didn`t change much for the extended period.
For Tuesday, model guidance remains consistent with a trough
passage producing a round of light snow over eastern CA-western
NV. This snow looks to start north of Portola-Gerlach during the
morning, then spread quickly southeast to near US-50 during the
afternoon, and south of US-50 by early evening. Overall forcing
looks relatively weak, with model soundings only showing moisture
depth up to 550-600 mb, resulting in snowfall rates too light to
produce much accumulation.
Overall snow amounts are expected to be 1" or less, except for
parts of northeast CA, the eastern Sierra and the central NV
mountains east of US-95 which could receive 1-3". However, with
much of this snow falling during the daytime, even these modest
accumulations are likely to be limited to unpaved surfaces.
As a result, overall travel impacts for lower elevations don`t
look to be very hazardous Tuesday evening. With sunset occurring
after 7 pm due to the PDT time change, roads should remain wet
through the peak evening commute. In addition, brisk northwest
winds behind this system should increase the drying rate of road
surfaces before temperatures fall below freezing. If any icy
patches develop, this is more likely late Tuesday night into early
Wednesday morning, and in areas south of US-50 where the window
for drying will be shorter. For the Sierra/Tahoe regions and
northeast CA west of Susanville, untreated roads could remain
slick with a minor accumulation of snow Tuesday evening into
Wednesday morning.
On Wednesday as the trough exits to the east, brisk northwest
winds and chilly temperatures are expected, with highs only in the
lower- mid 40s for lower elevations and 30s near the Sierra,
about 10-15 degrees below average. A few very light non-
accumulating snow showers remain possible for parts of west
central NV mainly from US-95 eastward.
From Thursday into next weekend, the medium range guidance favors
ridging over CA-NV, allowing for a dry weather pattern and slowly
warming daytime temperatures, although nights should remain cool
with overall light winds and limited cloud cover. A few scenarios
attempt to weaken the ridge with either a weak shortwave passage,
or an upper level disturbance slipping under the ridge axis, but
this would only bring some increase in cloud cover with no precip.
MJD
&&
.AVIATION...
Low pressure off the N California coastline will bring periods of
snow showers to the Sierra and Western Nevada this evening through
Sunday. Heavily based latest forecast on HRRR and GFS runs.
For TRK,TVL: High confidence in seeing some light snow
accumulation and MVFR/IFR conditions this evening into Sunday
morning. Some wind shear issues are possible through this
afternoon into early evening with mountain ridges currently
gusting above 50 mph.
For RNO,CXP: Much lower forecast confidence for W Nevada as models
are showing heavier snow pockets, but at varying locations from
run to run. Figuring we`ll see at least a period of light snow
late this evening into early Sunday morning with 40% chance of
light runway accumulations as air temps drop below freezing. This
could impact late evening and early morning peak traffic. If
banded snow stalls over the region, can`t rule out 2" or more but
confidence is low in this scenario. Sunday mid-morning onward
should see improving conditions during day time with more showery
precip and sun energy melting pavement.
For MMH: Pretty much left out of this initial storm with
precipitation from Central California breaking apart by the time
it reaches the Eastern Sierra, per the HRRR. Main snow
accumulation and reduced flight category issues at MMH may end up
being Sunday afternoon-evening with instability snow showers.
-Chris
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno