Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/17/21
AREA FORECAST DISCUSSION
National Weather Service Albany NY
941 PM EST Sat Jan 16 2021
.SYNOPSIS...
An upper level low will continue to impact eastern
New York and western New England overnight through the rest of the
weekend. Lake enhanced snow will continue across the southern
Adirondacks through Sunday morning, as westerly upslope snow
continues across the higher terrain of the southern Greens mainly
above 1500 feet. Otherwise, mostly cloudy conditions persist with
some scattered snow showers and flurries and blustery conditions for
the remainder of the region into Monday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Winter Storm Warning remains in effect until noon Sunday for
northern Herkimer and Hamilton Counties and for the southern
Green Mountains for the elevations above 1500 feet.
As of 940 pm EST...A cutoff low is centered over NY and PA
tonight. Cyclonic vorticity advection continues around the
cutoff, as the sfc cyclone according to the RAP is 987 hPa over
west-central Maine.
The forecast area has seen a transition to westerly upslope
orographic snowfall tonight over the northern Taconics, southern
Greens and northern Berkshires. Lake enhanced snowfall
continues over the Tug Hill Plateau spilling into the
southern/western Adirondacks. Lake instability class remains
conditional with marginal Delta T`s and instability values of a
couple hundred J/kg. The activity is not as organized, but still
a good fetch off the lakes.
The latest Froude Numbers from the NAM/GFS indicates values
rising into the 1-2 range where the flow is critical with the
strong west to southwest winds where the pcpn falls close to the
mtn ridge crest and on the lee side. Accumulations should
increase again along the southern Greens and western Adirondacks
where we are expecting an additional 3-6" at night. The
Warnings will remain in place. Some retooling of the PoPs was
done based on the radar returns and the latest 3-km HRRR.
Until noon tomorrow...Additional snow accumulations of 4 to 8
inches are expected across northern Herkimer and western
Hamilton counties. However across southern Vermont additional
snow accumulations of 1 to 4 inches are expected below 1500 feet
in elevation with 4 to 12 inches above 1500 feet.
South and east of the Capital Region will have less activity
tonight with some partial clearing near the mid Hudson Valley.
Some light snow showers are possible in the Mohawk Valley and
the Upper Hudson valley.
Lows tonight will be in the mid 20s to lower 30s.
West to southwest winds will pick up across the area with gusts
of 25 to 35 mph.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
Winter Storm Warning remains in effect until noon Sunday for
northern Herkimer and Hamilton Counties and for the southern
Green Mountains for the elevations above 1500 feet
The upper low will continue to move gradually northward as
ridging induced ahead of the next approaching short wave builds
in during the afternoon into the evening hours Sunday. This
ridging will quickly weaken and shift off to the east as the
long wave trough deepens to our west. The trough axis will move
across the area region Monday along with its associated cold
front.
The lake enhanced snow and upslope snow will continue into
Sunday morning with overall precipitation chances decreasing but
not ending as the day progresses and the favorable flow gets
disturbed. As the upper trough axis and its associated cold front
approach and cross the region we will have continued chances
for snow showers mainly across the higher terrain through the
day Monday. Dry out Monday night with some clearing expected.
Above normal temperatures with a more seasonable airmass being
ushered Monday night in the wake of the cold front.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
Focus during the long-term period continues to surround a couple
of rather weak shortwaves/associated low pressure systems that
will bring a couple of chances for some light snow to the forecast
area.
Deterministic forecast models and their ensembles continue to
advertise a shortwave approaching the forecast area during the day
on Tuesday. Clouds will be on the increase during the day on Tuesday
with precipitation in the form of snow moving into the region from
west to east Tuesday evening/night. Right now, it appears that most
of the snowfall will be confined to the SW Adirondacks, western
Mohawk Valley, the Berkshires, and southern VT. Snow showers will
linger into Wednesday morning before coming to an end by Wednesday
afternoon. Snow accumulations are expected to be light with this
storm system/shortwave being weak and coming with limited moisture.
We`ll get a brief break Wednesday afternoon/evening into Thursday
morning before our next chance for some snow showers as a strong,
larger storm system approaches from the northwest. Wednesday evening
into Thursday, clouds will increase eventually becoming mostly
cloudy by Thursday morning. Light snow will overspread the area from
west to east Thursday morning to Thursday afternoon. Synoptic snow
will persist into Friday before transitioning over to lake enhanced
snow. Upslope snow will also be occurring during this event. Lake
effect snow showers/upsloping are progged to persist till Friday
evening before coming to an end. There could still some lingering
lake effect snow showers over Herkimer county into Saturday morning.
Once again, snow amounts are expected to be light across most areas
with highest amounts confined to the higher elevations. A lot of
this is due to the fact that 1)the center of the storm system will
past well to our north meaning that the greatest forcing will be
north of our area in closer proximity to the center of the storm
system, 2) the fact that the storm system is expected to weaken as
it tracks across Ontario and Quebec, and 3) similar to storm systems
associated with the northern jet, there being limited available
moisture.
During this long-term period, the northern U.S. including the
Northeast U.S. will be under a mean flat upper trough. This will
translate to a cooler than normal bias in temperatures at the
surface during this time period. Daytime high temperatures will be
in the 20s/30s (with some teens across the SW Adirondacks).
Overnight low temperatures will be in the teens and 20s to start the
period, but will trend downwards into the teens and single digits by
Saturday night/Sunday morning. Low temperatures could fall below
zero across the SW Adirondacks Saturday night into Sunday morning.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A cutoff low continues to be situated over NY and PA tonight. A
series of disturbances rotating around the low tapping lake
moisture will continue cloudy conditions with scattered snow
showers and flurries from KALB north to KPSF tonight through
Sunday.
Some low stratus locally dense fog/mist continues to impact KGFL
early this evening with LIFR/IFR conditions. This should break
up between 00Z-04Z/SUN with MVFR/VFR conditions returning
as a disturbance moves through. MVFR cigs will persist
thereafter for most of the night with snow showers/flurries in
the vicinity. KALB will also be in the MVFR/low VFR range in
terms of cigs. A batch of snow showers will move through between
00Z-02Z and a TEMPO group was used for them. VCSH groups were
used most of the night with CIGS in between 2.5-3.5 kft AGL.
KPSF will have some upslope snow showers with CIGS/VSBYS
lowering from MVFR levels to occasional IFR or even LIFR levels.
A TEMPO group was used to address this prior to 04Z with MVFR
cigs in the 2-3 kft AGL with VCSH groups overnight. KPOU will
continue to have VFR conditions mid level clouds overnight.
After 12Z/SUN...Expect CIGS to continue in the MVFR/low VFR
range for KGFL/KALB/KPSF through the morning and into the
afternoon. In the cyclonic flow, there will continue to be some
lake effect, upslope flow snow showers and flurries. PROB30
groups were used at KALB from 13Z-18Z/SUN with MVFR conditions,
and 17Z-21Z at KPSF. KGFL we kept with VCSH groups. KPOU will
see some stratocumulus develop in the sct-bkn range range around
3.5 kft AGL in the late morning into the afternoon.
The winds will be southwest to west at 8-15 kts tonight with
some gusts to 18-25 kts. The winds will increase from the west
at 12-20 kts in the late morning into the afternoon with some
gusts around 30 kts at KALB/KPSF.
Outlook...
Sunday Night: Low Operational Impact. NO SIG WX.
Martin Luther King Jr Day: Low Operational Impact. Chance of SHSN...SN.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: Low Operational Impact. Slight Chance of SN.
Wednesday: Low Operational Impact. Breezy.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SN.
&&
.HYDROLOGY...
No widespread hydrological issues are not expected in the Albany
Hydro Service Area through the end of next week...
Total liquid equivalent from the storm system last night into today
ranged from a half an inch to an inch and three quarters. The
majority of higher liquid equivalent occurred over the higher terrain
of the eastern Catskills, southern Adirondacks, Berkshires and
southern Greens.
Additional lake enhanced and upslope snowfall will occur tonight
into Monday with the highest amounts over the western Adirondacks,
and the southern Green Mountains.
A clipper type low pressure system may bring some light snow Tuesday
night into Wednesday.
Overall flows will lower with the colder temperatures and the main
ptype will be snow.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Winter Storm Warning until noon EST Sunday for NYZ032-033.
MA...None.
VT...Winter Storm Warning until noon EST Sunday for VTZ013-014.
&&
$$
SYNOPSIS...IAA/Wasula
NEAR TERM...IAA/Wasula
SHORT TERM...IAA
LONG TERM...Evbuoma
AVIATION...Wasula
HYDROLOGY...Wasula
Area Forecast Discussion
National Weather Service La Crosse WI
534 PM CST Sat Jan 16 2021
.SHORT TERM...(This evening through Sunday)
Issued at 149 PM CST Sat Jan 16 2021
This afternoon the Upper Mississippi Valley region was situated in
between systems, beneath a low-amplitude mid-level ridge. Our recent
occluded low was advancing towards New England while a developing
shortwave was digging into the Northern Plains. Locally, we`ve had
some nuisance snow showers/flurries/drizzle to contend with today
due to a pesky 950-925mb frontogenesis band just west of the
Mississippi River. The RAP shows this fgen band fizzling out over
the next few hours as it creeps up to the MS River, so that should
lead to an overall diminishing trend. Will still keep mention of
flurries going given the very moist low levels and some weak low
level omega.
That upstream shortwave will be the feature of interest for tonight
as it drops into our region. While forcing will be weak in tandem
with limited moisture, there is model consensus for it to squeeze
out some light snow as it drops southeast through the region tonight
into early Sunday. QPF is very light, so the snow is not expected to
amount to more than a coating to perhaps a half inch in spots.
RAP/HRRR comp reflectivity point to south of I-94 as the main area
of impact through early Sunday afternoon, but have at least flurries
mentioned elsewhere for most of the day.
Lows tonight will range from around 20 to the mid 20s across the
area. Sunday`s highs will range from mid 20s to around 30.
.LONG TERM...(Sunday night through Saturday)
Issued at 149 PM CST Sat Jan 16 2021
There is no real clear or strong signal for precipitation over the
next several days, just some spotty low chances here and there. The
region will generally be under a northwest to southeast oriented
upper-level flow pattern. Multiple shortwaves pass through this flow
bringing several low chances for precipitation, but not expecting much
for accumulations if any at this time. Some light snow or
flurries may persist into the overnight hours on Sunday. On
Monday, another shortwave system passes through the region, but
the best chances for precipitation remain south of the area where
there is better forcing and moisture available.
From mid-week onward, model guidance is pinning a surface low
pressure system to track eastward through southern Canada while
remaining north of the Great Lakes Region. Associated troughs
extending from this low pass through the local area. Cold air
advecting into the area in wake of the passing waves will cool
afternoon temperatures into the teens for Friday and Saturday.
Otherwise, expect afternoon temperatures to be in the 20s to low
30s, with low temperatures from the single digits to low 20s.
Decided to stick with the blended model guidance keeping
precipitation chances nearly dry into the weekend. There is still
plenty of spread between the models with handling how these weak
shortwaves evolve and track through the region.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 534 PM CST Sat Jan 16 2021
Several weak troughs in northwest flow aloft will keep
cloud cover and intermittent light snow or flurries going through
the next 24 hours. Plan on IFR/LIFR conditions at KRST through the
period while mainly MVFR conditions expected at KLSE. Surface
winds will be light northwesterly, generally below 10kt.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Kurz
LONG TERM...Peters
AVIATION...DAS
Area Forecast Discussion
National Weather Service Dodge City KS
543 PM CST Sat Jan 16 2021
...Updated for aviation discussion...
.SHORT TERM...(This evening through Sunday)
Issued at 311 PM CST Sat Jan 16 2021
A cloudy and relatively warm afternoon as temperature trends from
the HRRR model warm temperatures about 10 degrees above normal
mid January highs. Many location might see an increase to
sustained wind speeds around 20 to 25 mph with the frontal
passage. As the cold front drops in Today, the drier air over
central Kansas will be taken over by higher dew points behind the
boundary in the 20s and 30s.
The secondary upper branch of the synoptic trough moves in
Tonight, providing deep layer subsidence and clearing sky. There
will be just enough surface pressure gradient to prevent winds
from going completely light, at around 10 knots overnight. There
is not a large spread amongst the models for overnight lows, with
plenty of consensus for the mid 20s overall.
.LONG TERM...(Sunday night through Saturday)
Issued at 311 PM CST Sat Jan 16 2021
We will remain under northwest flow on Sunday, however receive much
more insolation though the day. A reinforcement of cooler air should
cap temperatures at about 5 degrees cooler as well. A slight bump in
temperatures is likely Monday as weak downslope will be present
ahead of a dry surface trough. All of this is just in advance of a
noticeable cold front on Monday night. We should see he coolest
temperatures of the week Tuesday. That will also bring more
breezy/windy conditions late Tuesday/Wednesday as well as a bump
in temperatures to well above normal for highs Wednesday.
The Global spectral models are interesting toward the end of the 7
day period with potential for a significant cold front around
Thursday night or Friday. With the colder air in place and an
advancing synoptic scale trough moving though the four corners
region over the weekend, the possibility for a winter storm
impacting our region for the later half of the weekend looks
reasonable.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 536 PM CST Sat Jan 16 2021
North winds will diminish through 01z and then increase to
12-14kts with daytime heating between 16 and 22z. Winds will
become light toward the end of the period with the loss of daytime
heating and surface high pressure briefly building across the high
plains. VFR conditions can be expected with only scattered cloud
AOA070.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 27 49 28 52 / 0 0 0 0
GCK 25 48 26 50 / 0 0 0 10
EHA 27 49 28 51 / 10 0 0 10
LBL 25 50 25 51 / 0 0 0 0
HYS 26 49 26 51 / 10 0 0 0
P28 28 52 27 55 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Finch
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
630 PM CST Sat Jan 16 2021
...Short Term and Aviation Update...
.UPDATE...
Issued at 628 PM CST Sat Jan 16 2021
Quick update on chances for passing flurries/light snow showers
overnight:
- Did some minor updates to both timing/area, but bottom line is
any snow that does occur is still NOT expected to be a "big
deal" at all. As for timing: previous forecast held off any
mention of flurries/light snow showers until after midnight, but
based on various short term models and upstream radar trends it
appears that some of this possible activity could reach our
west-northwest zones as early as 9-10 PM so have moved up timing
a bit. As for coverage of overnight flurries/light snow showers,
previous forecast had entire CWA (coverage area) blanketed with
at least a flurry chance. However, latest short term models
clearly target roughly the western 1/3 of our CWA for having the
"highest" chances of seeing any limited activity, and our far
east-northeast as least favored. In fact, have "rolled the dice"
a little and removed any mention of flurries tonight from our
far northeast zones.
&&
.DISCUSSION...(This evening through Saturday)
Issued at 227 PM CST Sat Jan 16 2021
The weather is much calmer today in the wake of the system which
brought two consecutive windy days to our region (Thursday/Friday)
and this system has departed well to our east and was centered in
eastern OH around midday. The pattern aloft across our region
featured northwest flow ahead of upper ridging building along the
western CONUS.
Tonight, a 145kt jet will nose south from the northern Rockies
across the western/central plains states and will be driving a
shortwave trough across our region, then deepening the trough
just to our east by Sunday morning. Lift associated with the
progressing wave and favorable jet dynamics may be sufficient to
generate a few snow showers or flurries tonight. Short term models
differ on location of this light precip with the HRRR favoring
our central/eastern CWA whereas other models suggest precip more
along our western zones. Given this is a light event with little
if any accumulation, will maintain flurries across our entire cwa.
On Sunday the forecast dries out and heights begin to rise behind
the departing upper trough and we remain in between shortwaves
during the daytime hours. Northwest winds will increase again as
mixing deepens with gusts around 30 mph expected.
Sunday night into Monday in a progressive pattern, a shortwave
trough translates southeast from the northern Rockies and crosses
the plains, sending a cold front south through our region. Models
generate some light precip with this next system but this
primarily focused across northern and eastern Neb and have
maintained our dry forecast which is supported by model ensembles.
Heading into next week, the weather pattern becomes split with a
closed low in the southwest CONUS with our area influenced by a
progressive northern stream. Warmer air advects eastward around the
middle of the week and Wednesday is still shaping up to be the
warmest day with high temps in the 50s ahead of an advancing trough
and cold front. The forecast remains dry until Friday night/Saturday
but models have trended a little slower with the next system and
could see these chances getting pushed back until later next
weekend.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday)
Issued at 628 PM CST Sat Jan 16 2021
High confidence in VFR ceiling/visibility through at least the
vast majority of the period (and TAFS reflect this), although
there are few low-confidence caveats that could "mess up" this
expectation at least briefly: 1) A periodic low-end VFR ceiling
around 5K ft is expected mainly during the 06-15Z time frame,
which if this comes in a bit lower than expected could flirt with
upper-MVFR thresholds...2) There is an outside chance of a passing
snow shower mainly 03-08Z that could briefly reduce visibility
below VFR (currently covered with a generic VCSH/vicinity).
Turning to winds: modestly-breezy surface winds and modest low
level wind shear (LLWS) are the main stories. Starting with
surface winds, the overall-lightest speeds around 10KT or less
will occur this evening and then again very late in the period
Sunday afternoon. In between however, a disturbance diving in from
the north-northwest will kick up northwest winds a bit starting
late tonight, but with the overall-strongest speeds focused
14-22Z...typically sustained 15-20KT/gusting 20-25KT. As for LLWS,
have blanketed the entire 02-14Z time frame with a somewhat-
marginal mention as winds within roughly the lowest 1,500 ft. off
the surface will average around 40KT, setting up roughly 30KT of
shear magnitude between the surface and this level.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...Pfannkuch
DISCUSSION...Fay
AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Gray ME
1036 PM EST Sat Jan 16 2021
.SYNOPSIS...
Gusty winds and heavy precipitation ends for most areas this
evening with snow showers continuing in the mountains. Low
pressure will gradually exit through the Canadian Maritimes on
Sunday. A weak system crosses the region on Monday with another
system passing south of New England late Tuesday night and
Wednesday. A ridge of high pressure will cross the region
Thursday, followed by another system Friday into Saturday.
&&
.NEAR TERM /TONIGHT/...
1030PM UPDATE...
Adjusted hourly precipitation chances based on latest thinking
from radar trends. Still seeing areas of showers in the northern
portion of the area, with a broader area of light snow moving in
from the west as well. Still expect the remainder of the
activity to primarily affect mountain locations where a few more
inches are possible. Temperatures are still rather mild on the
coastal plain and the combination of snow melt and rainfall has
led to some fog mainly north of Lewiston/Augusta. Have included
this in the forecast as well.
630PM UPDATE...
Made some adjustments to the forecast mainly to drop the High
Wind Warning and the winter headlines south of the mountains.
Last of the precipitation is shifting to the northeast although
another round of snow is possible up north as the low pulls away
tonight, so the Winter Storm Warning will continue there.
ORIGINAL DISCUSSION...
RAP analysis shows low pressure sitting squarely overhead of
southwest Maine at this hour with rain and snow covering most of
the state, extending pack into northern and central New
Hampshire. Satellite shows the deep moisture plume, along with
heavy rainfall threat, has now tracked east of the area with
wrap-around deformation at the nose of a LLJ responsible for
what falls over our area this evening. Dual-pol radar, surface
observations, and spotter reports show the rain- snow line over
the foothills at about 1000 ft of elevation. Strong wind gusts
are now relegated to the Mid-Coast of Maine, where the LLJ still
resides, so have kept the high wind warning running there...
but have dropped wind headlines elsewhere.
Low pressure will continue to track north-northeastward toward
the upper Saint John River Valley tonight with winds gradually
turning to the southwest, then west, in its wake. Meanwhile the
mid-level wave will continue to produce favorable forcing to
continue snow over the mountains tonight... especially during
the pre-dawn hours when the upper level dry slot shifts away and
dendrite growth becomes favorable again. Thus a few more inches
of snowfall is expected over the northern counties, especially
at higher elevations where temperatures are more favorable. The
Winter Storm Warning continues there through 7 AM Sunday to
account for this.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Today`s storm system will very slowly track north away from the
area tomorrow as it becomes vertically stacked. It doesn`t pull
away very quickly however... as a result tomorrow will be a
fairly brisk day with cooler temperatures mainly in the 30s over
the area and a stiff west wind. While the mountains and north
will have clouds most of the day, breaks in the clouds toward
the south and coastal plain will allow temperatures to approach
40 which produces favorable mixing conditions to bring frequent
gusts of 30 kts or more to the surface. Steep low-level lapse
rates along with continued cyclonic flow aloft also produce a
good environment for snow squalls... while moisture depth over
the lowlands don`t support widespread issues there could be a
few periods over the mountains and perhaps the upper Connecticut
River valley where travel will be very difficult in white-out
snow and wind.
Low pressure pulls away into Labrador Sunday night which allows
the PGF to slacken some, thus allowing winds to gradually relax
overnight. Snow showers will decrease in coverage and intensity
as well with lows down into the upper teens (north) to near 30
(coast).
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Models are in relatively good agreement bringing a short wave
across the region Monday afternoon into Monday evening. A weak
surface wave of low pressure may form with this feature allowing
for a chance of snow showers in all portions of New Hampshire
and western Maine. Temperatures will still be above normal for
this time of the year, with readings in the 30s across southern
and central areas. The warm boundary layer temperatures may
allow for a few rain showers to mix in right along the
coastline.
Another weak system will cross New England Tuesday night into
Wednesday. This is a clipper type area of low pressure which
will allow for another chance for precipitation across Maine
and New Hampshire. It will be cooler with temperatures near or
just below normal for this time of the year so any
precipitation should remain in the form of snow showers.
The fast paced short waves will continue to race across the
northern portion of the CONUS. Therefore, after a weak ridge
passes the region Thursday, another system will bring a chance
for a period of light snowfall or scattered snow showers to the
region Friday and Saturday.
While 12Z guidance remains in relatively good agreement from
model to model, timing issues with snow showers may be
challenging throughout the week.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Short Term...Improvements to MVFR are already being seen over
parts of southern New Hampshire and the Maine coast with
further, gradual improvement to VFR through tonight. The
exception is at KLEB and KHIE where -shrasn and eventually shsn
will persist with restrictions overnight. These sites likely
stay MVFR for CIGS tomorrow with occasional VIS restrictions in
SHSN. Southeast winds are now decreasing and will gradually turn
to the southwest, then west by tomorrow... becoming gusty to
about 30 kts during the day.
Long Term...A few weak systems will be crossing the region this
week, possibly bringing periods of light snow and MVFR
conditions to the region. This will most likely be Monday,
Tuesday night into Wednesday and again possibly Friday into
Saturday.
&&
.MARINE...
Short Term...Winds will decrease for a brief time this evening
as southeast storm force winds track away and to the north of
the region. Seas however will remain active with waves remaining
around 10 ft at the least through tonight. An offshore gale
returns late tonight through tomorrow... certainly for the outer
waters, likely for Penobscot Bay, and possibly for Casco Bay.
Long Term...Winds and seas will likely reach SCA thresholds on
Monday and Tuesday as a westerly gradient remains over the
region.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Warning until 7 AM EST Sunday for MEZ007>009.
NH...Winter Storm Warning until 7 AM EST Sunday for NHZ001-002.
MARINE...Small Craft Advisory until 1 AM EST Monday for ANZ153.
Gale Warning from 1 AM Sunday to 1 AM EST Monday for
ANZ150>152-154.
&&
$$
NEAR TERM UPDATE...Kimble
SHORT TERM...Cannon
LONG TERM...Casey
Area Forecast Discussion
National Weather Service Hanford CA
502 PM PST Sat Jan 16 2021
.UPDATE...
High Wind Watch has been issued for parts of the Sierra and
Foothills on Monday and Tuesday.
&&
.PREV DISCUSSION... /issued 115 PM PST Sat Jan 16 2021/
SYNOPSIS...
A change from high pressure over the region to a dry cold front
and strong winds aloft by Monday will bring strong winds to part
of the area. A foggy morning and a dry, warm Sunday are forecast
to occur across the San Joaquin Valley as high pressure remains in
place. A couple of disturbances next week could allow for strong
northeasterly winds in the Sierra Nevada and Kern County
Mountains.
DISCUSSION...
Dense fog occurred again this morning due to the influence of the
ridge trapping moisture in the lowest levels of the atmosphere.
This ridge is going to remain in place tonight, so fog looks
likely again for us. The the HRRR and NAMNEST are forecasting fog
starting to form around midnight tonight and dissipating it around
11 AM tomorrow, so a Dense Fog Advisory has been issued for that
time range across the SJ Valley north of Bakersfield.
The situation gets more interesting next week as a couple of
systems are try to disrupt the quiet ridge pattern we have had for
a while. Model guidance is starting to get more consistent with
the evolution a disturbance pushing the ridge of high pressure
westward tomorrow night, which would allow for another, larger
trough to move over the area on Tuesday. This second system could
generate a Mono Wind event if everything were to unfold as some
models are portraying, but there are a lot of moving parts for
this to occur. So while confidence is slowly increasing for
increased winds next week, it`s probably too early to tell if the
jet axis aloft will align itself properly with the Southern Sierra
Nevada to support a bona fide Mono Wind event by late Monday
going into Tuesday. Regardless of exactly how this pattern
unfolds, it does seem likely that increased winds will be an
impact next week for several areas in our forecast area.
As the week progresses, global models are showing the potential
for another system to enter the region that could produce the
first precip we have seen in a little while. However, we need to
get through Monday and Tuesday first to really get a grasp on what
happens by Friday. Nonetheless, the overall pattern does seem to
favor more activity than we have seen lately.
AVIATION...
IFR conditions with areas of LIFR/VLIFR in fog are likely to occur
after 08z Sunday through 19z Sunday. VFR conditions can be
expected over the remainder of the central California interior
during the next 24 hours.
AIR QUALITY ISSUES...
On Saturday January 16 2021... Unhealthy for sensitive groups in
Fresno... Kern and Tulare Counties. Fireplace/Wood Stove Burning
Status is: No Burning Unless Registered in Kings... Madera...
Merced and Tulare Counties. No Burning For All in Fresno and Kern
Counties.
Further information is available at Valleyair.org
CERTAINTY...
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
an/or to provide feedback.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from midnight tonight to 11 AM PST Sunday for
CAZ180>188.
High Wind Watch from Monday afternoon through Tuesday morning
for CAZ190-192-193.
&&
$$
public...Bollenbacher
aviation....Bollenbacher
weather.gov/hanford
Area Forecast Discussion
National Weather Service Lincoln IL
905 PM CST Sat Jan 16 2021
.SYNOPSIS...
Issued at 251 PM CST Sat Jan 16 2021
Light snow will spread across central Illinois tonight and
continue into Sunday, as a storm system tracks southeast across
the region. Amounts of an inch or two are likely.
&&
.UPDATE...
Issued at 905 PM CST Sat Jan 16 2021
Upper level shortwave approaching west central IL will continue to
produce increasing coverage and rate of snow overnight as it moves
into central IL. Initially, some reports of freezing drizzle are
noted in west central IL due to shallow cloud depth but this
should increasingly switch to all snow overnight as deeper lift
associated with the shortwave develops. Overall, updates this
evening are minimal, with afternoon forecast package in good
shape overall.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 251 PM CST Sat Jan 16 2021
Earlier round of snow exited the forecast area by midday, with
just some patches of drizzle or light snow lingering over the
eastern CWA. Robust shortwave was currently located in eastern
South Dakota and will close off an upper low over central Illinois
Sunday morning. While precipitation remains spotty this evening,
an increase in snow is expected in the 9-midnight time frame west
of the Illinois River, spreading southeast after midnight. 18Z
HRRR suggests the snow could be cutting off as early as midday
Sunday, though will go with a more slower diminishing through
early afternoon as the associated surface boundary exits eastern
Illinois. Accumulations not expected to be overly generous, but an
inch to 2 inches appears reasonable over most of central Illinois,
with up to an inch south of I-70. Main impacts on travel would
likely be in the overnight and morning hours, as temperatures
creep up to the freezing mark in the afternoon.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 251 PM CST Sat Jan 16 2021
Lingering light snow near the Indiana border is expected to move
out early Sunday evening, with mainly dry conditions following
into Monday. Another shortwave is expected to drop southeast
across the Dakotas Monday afternoon, before tracking across the
Great Lakes region. Central Illinois will be caught up in the
converging area of the northern and southern jet streams. The main
synoptic models all squeeze out some QPF in a band across the
mid-Mississippi Valley, though the European model is more focused
south of I-70. Will add some chance PoP`s for light snow Monday
night across mainly the middle third of the forecast area, though
soundings show it may end as a bit of freezing drizzle as ice
crystals aloft are lost.
With a large upper low cutting off southwest of California early
this week, the upper pattern over us won`t be conducive to any
significant changes until the low weakens and ejects northeast
around Thursday. Both the GFS and European model keep much of its
remnants to our south, though some precipitation may spread
northeast Wednesday night as a weaker wave precedes it.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 526 PM CST Sat Jan 16 2021
IFR cigs are in place across most of the central IL terminals this
evening, and are expected to continue through most of the forecast
period, potentially decreasing overnight as another disturbance
moves into the area bringing additional light snow. This snow
should bring general IFR vsbys as well starting around 05Z-07Z.
Potentially lower cigs/vsbys possible locally in the LIFR range.
Light snow should begin to taper off from west to east near the
end of the forecast period. Winds W 7-12 kts through the period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...37
SYNOPSIS...Geelhart
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...37
...Update to aviation forecast discussion...
.DISCUSSION...
Issued at 228 PM CST Sat Jan 16 2021
An amplified weather pattern persists over North America with an
upper level trough over the east coast and ridging off the CA
coast per the 20Z water vapor imagery. Within the northwest flow
over the Great Plains, a couple pieces of energy were noted, a
short wave moving across the southern high plains and a speed max
diving south through MT. At the surface, weak high pressure was
seen across the central plains.
For tonight and Sunday, there remains the possibility for some light
snow across central KS as the speed max to the north causes a
shortwave to amplify over the central plains. Models vary on the
amount of saturation as the energy moves across the area, but there
has been a consistent signal from the RAP and GFS for enough
saturation along with some modest vertical motion for some light
snow. Have left POPs less than 20 percent given the uncertainty in
available moisture, but I would not be surprised if there is a
narrow band of light snow (mainly a dusting) across the western
parts of the forecast area by tomorrow morning. Lows tonight should
fall back into the 20s with dry air in place and winds becoming
light. Highs Sunday look to be pretty similar to todays with no real
temperature advection progged by the models and a continued mix of
sun and clouds likely. So have highs forecast to range from around
40 across the northeast where there may still be a little snow to
the middle 40s south and west.
A series of weak systems are forecast to move across the central
plains through the first half of next week. None of these systems
appears to be very dynamic for the forecast area with only the
moisture in place to work with. So the forecast remains dry through
Wednesday. However precip chances are non-zero. The next wave to
keep an eye on is Sunday night and Monday as another shortwave digs
southeast. The GFS and ECMWF tend to keep the forcing with this
feature mainly north of the forecast area while the NAM shears it
out as it approaches northeast KS with the bulk of energy cutting
off over the southwest. Since the NAM is the only solution
developing QPF over a limited part of the forecast area, have kept
POPs pretty low. Another piece of energy may move across the region
Wednesday. But again omega fields do not look all that impressive
with generally dry mid level air. The cutoff system over the
southwest is progged to weaken and move across the southern plains
Thursday and Thursday night with the GFS and ECMWF keeping the
moisture south of the forecast area. So only have some slight chance
POPs across Anderson county as this system passes. Then shortwave
ridging is progged to redevelop for the weekend with the next low
pressure system lifting out of the southwest just beyond the
forecast period. The national blend of models has some slight chance
POPs for north central KS on Saturday. Think this may be a little
premature and don`t have much confidence in precip occurring on
Saturday as the deterministic solutions keep the dynamics for the
best vertical motion to the west until Sunday. If this trend
continues, the POPs on Saturday can probably be lowered.
Temps do not look to swing a whole lot from day to day as northwest
flow keeps the occasional surface high moving through the region.
Wednesday has the potential to be one of the warmest days of the
next seven with some decent southwesterly low level flow advecting
warm air north. Have highs on Wednesday in the middle 50s for most
areas. In general temps look to remain mild with readings near or
just above climatological norms.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 522 PM CST Sat Jan 16 2021
VFR conditions are expected through the period. There may be a
brief period of mvfr cigs in the 19Z to 22Z time period at TOP and
FOE, but looks to stay to the east at this time. Winds light west
to become northwest around 15 kts with gusts to 24 kts after 16Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Wolters
AVIATION...53