Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/13/23
AREA FORECAST DISCUSSION
National Weather Service Albany NY
958 PM EST Thu Jan 12 2023
.SYNOPSIS...
A low pressure system and a warm front will bring steady
rainfall for most locations overnight. Some areas of freezing rain
are possible across portions of the southern Adirondacks and
southern Greens until early Friday morning before changing to rain.
The rainfall will taper off on Friday and it may end as a period of
snow for the western Adirondacks. Cooler, breezy and dry conditions
are expected for the weekend. Temperatures will return back above
normal next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 955 PM EST...A positively tilted mid and upper level
trough continues to impact the forecast area tonight, as low
pressure approaches from the Ohio Valley and western PA based on
the latest RAP. The warm front and cyclone continues periods of
moderate rain with some localized areas of freezing rain across
the southern Adirondacks in the northern Hamilton and northern
Warren Counties, as well as portions of southern VT, where the
Winter Weather Advisory continues. Some pockets of freezing rain
continue to be possible in eastern Windham County, where some
temps are around 32F. We have an SPS going there. We did cancel
northern Fulton County with this update with temps in the mid
and upper 30s. The NYS mesonet shows temps have warmed into the
33-35F range across portions of the southern Adirondacks and
the Lake George Saratoga Region. Chestertown is still 32F. To
side on caution we kept the Advisory going in this area of the
Adirondacks.
The 850 hPa low-level jet continues to be from the
south/southwest at 45-65 kts tapping some Gulf moisture with
anomalous PWATs +2 to +3 STDEVS (based on the NAEFS) above
normal. Periods of moderate to locally heavy rain are possible
across the forecast area due to the strong QG lift. Some
thunderstorms popped up over the southern Berkshires, Litchfield
Hills, mid Hudson Valley and southeast Catskills. We expanded
the slight chance of thunderstorms a few more hours until
midnight with the SPC RAP mesoanalysis indicating Showalter
values in the 0 to -1C range in the southeast extreme of the
forecast area. Some MUCAPE is also in the southeast portion of
the forecast area closer to the warm front of a few hundred J/kg
or less. A lull in the rain is possible in the early morning
hours, as a dry slot briefly moves in south and east of the
Capital Region with the warm front lifting through, the latest
3-km HRRR/NAM indicates showers or intermittent rain should fill
back in.
Temps will rise overnight into mid/upper 30s over the southern
Dacks to 40s across most of the region with lower 50s in the mid
Hudson Valley, southern Taconics, and NW CT. Southeast winds
over the eastern Catskills, Taconics and western New England
higher terrain will continue 10-20 mph with some gusts around
30-35 mph. Stable layers close to the surface should help
prevent winds from getting closer to advisory criteria, so no
wind headlines at this time.
Towards daybreak, the main area of low pressure will be lifting
from NE PA into the Catskills. Another round of steady precip
will be occurring on the western side of the low pressure area,
which will mostly be over western and central NY. However, as
the low pressure continues to track to the northeast, this round
of steadier rainfall may start to track into parts of the Mohawk
Valley and Adirondacks towards daybreak, while additional
showers push northward on the eastern side of the storm.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Low pressure will be moving from the Catskills across the Mohawk
Valley and into the Adirondacks on Friday morning. Steady
rainfall will be occurring to the west, with bands of showers
east of the low pressure center. The steadiest precipitation
will be ending around midday or the early afternoon as the low
starts to depart off to the northeast. As colder air works into
the region, there may be a changeover from rain to snow across
the western and central Adirondacks during the morning hours. A
few inches are possible across the highest terrain before precip
winds down by afternoon.
Elsewhere, showers should be ending as the storm`s cold front
moves through the region by either the late morning or early
afternoon hours. Behind the front, temps will start falling for
the afternoon hours. Most areas should be down into the 30s by
the late afternoon or early evening hours on Friday. Winds will
be switching to the west by afternoon and gusty at times.
Despite being behind the front, skies will continue to stay
fairly cloudy through the day.
With the upper level trough overhead, it will continue to stay
fairly cloudy into Friday night. A few breaks are possible late,
especially for southern areas. However, it should be dry, aside
from a few spotty snow showers or flurries over the Adirondacks.
Temps will fall into the teens into the 20s by late Friday
night.
Drier, cooler and continued breezy conditions are expected on
Saturday behind the departing storm system. Some breaks of sun
are finally expected to occur and it should be precip-free for
most of the area. Temps will be in the mid 20 to mid 30s and
breezy north to northwest winds will still be in place.
Temps will be falling into the teens on Sat night with clearing
skies continued dry conditions with no precip. It will still be
fairly breezy into the overnight hours thanks to storm offshore
the eastern seaboard keeping a strong pressure gradient in
place. Some gusts may still be in the 15 to 25 mph range at
times.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
The extended forecast opens with high pressure at the surface and
mid and upper level ridging building in over NY and New England with
fair and dry weather to close the weekend and for the opening of the
week/the MLK holiday. Temperatures will continue to be near or
slightly above normal with highs in the 20s to lower/mid 30s over
the higher terrain, and 30s in the valleys moderating into the mid
30s to around 40F on Monday. Lows due to radiative cooling will be
in the teens to lower 20s with single digits over the Adirondack
Park.
Monday Night into Tuesday...The deterministic medium range
guidance/ensembles indicate the ridge break down with a northern
stream disturbance approaching from the Great Lakes Region. The
system may completely shear out and pass south of the region with a
closed/cutoff low moving over northern Maine and New Brunswick.
Clouds increase Mon night with a slight or low chance of snow/rain
showers or possibly a light wintry mix on Tue, though confidence
remains low for any ice potential. After lows in the upper teens and
mid 20s, expect highs to moderate into the 30s to lower 40s.
Tuesday night into Thursday...A weak cold front moves across the
region Tuesday night with flat ridging building in for Wednesday.
Isolated to scattered snow showers are possible northwest of the
Capital Region Tuesday night before a brief period of fair weather
mid week. The next system approaches from the Midwest and
western/central Great Lakes Region based on the ensembles and medium
range guidance bringing the next bout of precipitation. Based on
the persistent track west of NY and New England, a light snow/mix to
rain scenario is favored for THU with temps running above normal
for mid-Jan by about 10 degrees to close the extended forecast
period.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Steady rain will continue expanding northeast across the TAF
sites through 02Z/Fri. Rainfall intensity could be moderate to
briefly heavy at times. Freezing rain could occur at KGFL
through around 01Z/Fri. Periods of light to moderate rain are
expected to continue overnight into Friday morning.
Cigs are expected to be mainly MVFR/IFR overnight, with chances
for LIFR increasing after 05Z/Fri. Vsbys will be mainly MVFR/IFR
once rain begins, with some possibility for LIFR VSBYS
developing after 05Z/Fri with areas of fog, especially at KGFL
and KALB.
IFR/LIFR conditions are expected Friday morning. Conditions
could lift to MVFR at KPOU and KPSF in the wake of a warm front.
Conditions should gradually improve to MVFR (mainly for Cigs)
at all sites during Friday afternoon, with VFR possible at KPOU
after 21Z/Fri.
Winds will be mainly light from the north to northeast at less
than 5 KT at KGFL and KALB overnight, while becoming southeast
at KPOU and KPSF at 5-10 KT with some gusts possibly reaching up
to 20 KT. Winds will become northwest in the wake of a cold
front Friday afternoon, with speeds of 8-12 KT, along with
possible gusts up to 20-25 KT.
Low level wind shear will remain likely through this evening at
KGFL/KALB, and much of the night at KPSF/KPOU, as surface winds
remain light from the north/northeast while winds around 2000 FT
AGL increase from the southeast to 30-40 KT (surface winds will
become southeast at KPSF and KPOU later this evening, however
winds around 2000 FT AGL will remain strong from the southeast
at around 40 KT).
Outlook...
Friday Night: Low Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Martin Luther King Jr Day: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Chance of SHRA...SHSN.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Winter Weather Advisory until 5 AM EST Friday for NYZ033-042.
MA...None.
VT...Winter Weather Advisory until 1 AM EST Friday for VTZ013-014.
&&
$$
SYNOPSIS...Frugis/Wasula
NEAR TERM...Frugis/Wasula
SHORT TERM...Frugis
LONG TERM...Wasula
AVIATION...KL
Area Forecast Discussion
National Weather Service Boston/Norton MA
954 PM EST Thu Jan 12 2023
.SYNOPSIS...
Intensifying low pressure tracking across PA/NY into northern New
England, will bring showers with locally heavy rain tonight and
Friday morning to southern New England, along with mild and windy
conditions. The trailing cold front sweeps across the region Friday,
but then stalls just offshore Friday night. Temperatures trend more
seasonable for the weekend. Surface low pressure tracks from
the Carolina coast towards the bench mark for Sunday, which may
produce scattered rain and snow showers. A warming trend begins
Monday and continues through much of the week. Still plenty of
uncertainty surrounding surface features and precipitation.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
10 PM Update...
Moderate to heavy rain has overspread most of the region, with
the heaviest rain centered across SE MA/RI heading towards Cape
Cod. While most locations have warmed into the 40s to near 50F,
cold air remains trapped between the high terrain of western CT
and the CT River Valley. While this currently has no impact on
P-Type, it is worth mentioning temps are running behind the
current forecast in that region, thus, blended the forecast and
the HRRR with this update.
Winds are also behind the 8 ball, with gusts of 20-30 mph being
reported along the south coast, Cape, and Islands (in contrast
to the current forecast which calls for 30 KNOTS). Anticipating
that while winds are a bit subdued at this hour, they will
really start ramping up in the next 3 hours, thus, just
interpolated obs into the forecast overnight to show the
upward trend.
A few rumbles of thunder/flashes of lightning were reported to
our southwest, but current ENTLN 5 minute flash products show
little to no activity at this hour. With that said, the greatest
instability is currently centered over CT (with 100-250 J/kg
MUCAPE per current SPC Mesoanalysis), so it is possible that we
have a few rumbles redevelop over the next few hours.
7pm Update:
Widespread rain across SW New England as a warm front pushes
north. Still, can not rule out a rumble of thunder as lightning
has been detected over the waters south of Long Island. Using an
in-house tool, that line of showers arrive across southern New
England over the course of the next 30 to 90minutes. In addition,
temperatures are also rising this evening, KWST is already at
47F! Those temperatures will continue to rise overnight.
Did not make any changes to the near term forecast as the
previous forecast remains on track.
Please see the previous discussion below.
----------------------------------------------------------------
Highlights...
* Temps rising thru the 50s overnight in the coastal plain
* Showers with locally heavy rain after 8 pm
* SSW winds gusting up to 40-50 mph late tonight
Vigorous short wave moving across the TN valley late this afternoon
will impact SNE weather with widespread showers, locally heavy rain
and gusty SSW winds late tonight of 45-50 mph across southern RI
into southeast MA. As this short wave advects northeast, good height
falls at H7 & H85 yield a robust low level SSW jet of 60-70 kt,
traversing the south coast after 06z. Impressive jet dynamics yields
strong forcing for ascent and copious moisture advection, with PWATs
1+ inches. Thus, widespread showers after 00z or so, along with
embedded downpours from time to time. Low prob of isolated thunder
given marginal instability, as dew pts rise into the low 50s. Hi res
guidance indicates very strong low level thermal advection with
surface temps rising into the mid/upper 50s in the coastal plain
toward morning, including the Boston to Providence corridor. This
will ease the low level inversion and promote SSW winds in the warm
sector to gusts up to 40-50 mph at times, especially in heavier
downpours. There, we`ve hoisted a wind advisory for southern RI into
southeast MA, including Cape Cod and the Islands. Areas of fog
tonight, as warm front lifts slowly northward across the region.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
350 PM update...
Friday...
Highlights...
* Very mild with highs in the mid/upper 50s
* Downpours & gusty winds in the morning
Showers with heavy downpours Fri morning, especially across RI and
eastern MA, where a broken fine line of low top convection is
possible. This will be in response to the nose of the low level jet
moving across the area. SSW wind gusts up to 40-50 mph possible
during the morning across south/central RI into southeast MA,
especially in heavy downpours. Storm total rainfall of 0.75 to 1.5
inches is likely, with heaviest amounts on the nose of the low level
jet across eastern CT/RI and southeast MA. Thus, could be a slow
morning commute. Although, it will be mild with daybreak temps in
the mid to upper 50s in the coastal plain, courtesy of low level SSW
jet. Dry slot moves across the area Fri afternoon, thus a drying
trend for the PM hours. Although remaining very mild, with frontal
passage not until late in the day or evening. Record highs are in
the low 60s, except 59 for BDL. Will probably fall just short, by
nonetheless, very mild. See climate section below for records.
Friday night...
Dry, post frontal, but front stalls offshore as mid/upper trough
evolves into a closed low along the Carolina coast, yielding SSW
flow along the coast. Mainly dry weather, but could have some
showers clip the outer Cape. Seasonably cold, with lows in the 20s
inland, 30-35 along/near coast. Becoming blustery overnight, with
increasing northerly winds.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
350 PM update...
Highlights...
* Temperatures trend more seasonable for the weekend. The greatest
chance for sct`d rain or snow showers is Sunday, though confidence
still remains low.
* A warming trend begins Monday and continues through much of the
week. Still plenty of uncertainty surrounding surface features and
precipitation.
Saturday through Sunday Night...
Overall a drier period of weather, but there are chances for light
precipitation as a broad area of low pressure meanders over the
southern waters. The area that has the greatest chance for sct`d
showers, snow/rain, would be areas east of I-95 with the most likely
areas being southeast MA, Cape Cod, and the Islands. As for
temperatures, the afternoon high for Saturday and Sunday are
noticeably colder than the previous days, but are between 3F and 5F
above the climatological norm.
Latest 12z guidance continues to show a mid-level ridge over the
North Atlantic Ocean, blocking a weak surface low pressure system
off the Carolina coast. Also, blocking the moisture from completely
exiting the New England area, trended more cloudy for Saturday
afternoon as a result. Aloft, the amplified 500mb trough is over the
eastern seaboard with shortwaves pivoting around it, which will help
to produce a few rain/snow showers. The highest PWATs are located
across southeast MA, Cape Cod, and the Islands, this would be the
area with the greatest risk of a sct`d shower.
The better chance for any rain/snow showers would arrive Sunday with
a surface low tracking towards the NNE, in the vicinity of the bench
mark, based of 12z ensembles. There is still a great deal of
uncertainty, the biggest question that remains, how close does the
low pass to southern New England? Given this period is four days
away, we will look at this probabilistically. ECMWF ensembles have an
area over Plymouth County with a 50-60 percent chance of exceeding
at least 1.0" of snow, 30-40 percent chance of exceeding 3.0", and
even a 10% chance of exceeding 6.0". As for the GFS ensembles, the
area with the greatest chance of snow is Cape Cod and Martha`s
Vineyard with a 40-50 percent chance of exceeding 1.0" and 20-30
percent chance of exceeding 3.0". It`s worth noting that these
probabilities have increased slightly since the 06z run.
In addition, temperature are marginal, sounding like a broken record
over here. For example, looking at a forecast sounding for KPYM,
there is a warm nose from 900mb to 700mb, with an above 0C layer
from 850mb to 750mb. As you can imagine, this part of the forecast
is not one to lock in. You are going to want to come back and check
the latest over the coming days.
For this forecast, kept chance -SN and -RA in an area along I-95 and
points east, Cape Ann, Boston Metro, Providence Metro, Cape Cod, and
the Island.
Early next week:
Forecast confidence diminishes into early next week. There is some
agreement in high pressure being in place, allowing for a dry day on
Monday. Beyond that, models are not in great agreement with a
potentially retrograding surface low over the Gulf of Maine. Because
of how low confidence is during this period, did not spend too much
time nitpicking.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
00z update...
After 00z...high confidence on trends, lower on precise timing &
exact details.
Increasing SSW winds tonight, with strongest winds across RI and
eastern MA, with gusts up to 45 kt from 05z-12z Fri. IFR/LIFR
inland, MVFR/VFR along the coast. Showers all terminals, with
heavy rain at times.
Friday...high confidence, lower on precise timing &
exact details.
IFR/MVFR in showers, with locally heavy rain in the morning
along with strong SSW winds across coastal RI and southeast MA
until about noon, with gusts up to 45 kt. Trending drier Friday
afternoon, and trending toward VFR for the evening push.
Friday night...high confidence. VFR cloud bases and dry, however
a round of showers possible across Cape Cod and the Islands.
KBOS Terminal...High Confidence in TAF trends, lower in exact
details and precise timing.
LLWS 02z-12z Fri with low level SSW jet of 50-60 kt at 3 kft moving
across southeast MA. We will have to watch potential broken line
of heavy rain showers with gusty winds 07z-14z Fri.
KBDL Terminal...High Confidence in TAF trends, lower in exact
details and precise timing.
Marginal LLWS 04z-11z as low level SSW jet tracks across coastal
CT/RI/southeast MA.
Outlook /Saturday through Tuesday/...
Sunday: VFR. Strong winds with local gusts up to 40 kt. Chance
SHSN, chance SHRA.
Sunday Night: VFR. Windy with gusts up to 35 kt.
Martin Luther King Jr Day through Monday Night: VFR. Breezy.
Tuesday through Tuesday Night: VFR. Slight chance SHRA, slight
chance FZRA.
Wednesday: Breezy.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
00z update...
Tonight...intensifying low pressure moves from PA/NY into northern
New England. SE winds this evening, becoming SSW after midnight and
increasing to 25-35 kt. Vsby limited in showers and fog, with
locally heavy rain.
Friday...Low pressure moves across northern New England, with strong
SSW winds 25-35 kt continuing in the morning, then easing and
shifting to the SW. Showers and fog will limit vsby, but improving
with the wind shift. Heavy showers with locally stronger winds
possible in the morning.
Friday night...cold front enters the waters in the evening, then
stalls offshore. Increasing north winds develop. Showers offshore,
dry near shore.
Outlook /Saturday through Tuesday/...
Sunday: Moderate risk for gale force winds with gusts up to
35 kt. Rough seas up to 14 ft. Chance of rain showers, chance
of snow showers.
Sunday Night: Strong winds with gusts up to 30 kt. Rough seas
up to 13 ft. Slight chance of rain showers.
Martin Luther King Jr Day: Moderate risk for Small Craft
Advisory winds with gusts up to 30 kt. Rough seas up to 11 ft.
Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas.
Tuesday through Tuesday Night: Winds less than 25 kt. Seas up
to 5 ft. Slight chance of rain showers.
Wednesday: Winds less than 25 kt. Seas up to 5 ft.
&&
.CLIMATE...
Record Highs for January 13th:
BOS: 63F - 1932
ORH: 62F - 1932
PVD: 63F - 2018
BDL: 59F - 2018
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Wind Advisory until 2 PM EST Friday for MAZ017>024.
RI...Wind Advisory until 2 PM EST Friday for RIZ002-004>008.
MARINE...Gale Warning from 3 AM to noon EST Friday for ANZ230.
Gale Warning until 4 PM EST Friday for ANZ231>235-237-250-251-
254>256.
Gale Warning until 1 PM EST Friday for ANZ236.
&&
$$
SYNOPSIS...Nocera/Gaucher
NEAR TERM...Nocera/Gaucher/KS
SHORT TERM...Nocera
LONG TERM...Gaucher
AVIATION...Nocera/Gaucher
MARINE...Nocera/Gaucher
CLIMATE...
Area Forecast Discussion
National Weather Service State College PA
919 PM EST Thu Jan 12 2023
.SYNOPSIS...
Rain will overspread central Pennsylvania by this evening and
continue tonight. Rain will change to snow over the northern
and western Alleghenies on Friday with a minor accumulation
expected through Friday night. Snow showers will end early
Saturday. Mild temperatures today and tonight will trend colder
and bottom out near seasonal averages during the first part of
the weekend before resuming a warmer-than-normal trend into
next week.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
Regional radar at 02Z shows the steadiest rain has shifted
north of Pa associated with nose of low level jet and best warm
advection. However, additional showers are still to come as
surface low, located near KPIT at 02Z, and trailing cold front
track across the state tonight. MRMS multisensor qpe through 01Z
ranges from around 0.66 inches over the western counties to
just a few hundredths of an inch from Harrisburg southeastward.
The focus for the additional rain overnight should be over the
southeast counties associated with increasing forcing ahead of a
potent shortwave lifting north across the Mid Atlantic late
tonight. A thunderstorm is even possible later tonight across
the southeast part of the forecast area, where the latest RAP
indicates the presence of some minimal capes ahead of
approaching cold front.
Sfc cold front will sweep west to east late tonight through the
predawn hours Friday. Colder air behind the front will drop air
temps to around the freezing mark and change rain to snow with
a coating possible over the western and northern Alleghenies by
daybreak. Winds will shift to the west and increase into Friday
morning with gusts up to 25-35 mph. Low temp gradient from west
to east will be about 15-20 degrees with minTs around 30 along
the western mtns to around 45-50F from MDT and points to the SE.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Breezy and noticeably colder over western PA to end the week
with highs falling about 10F from today and gusty wind adding to
the chill. A tight pressure gradient and passage of a strong
isallobaric couplet suggests winds will ramp up quickly around
dawn. Bukfit soundings support increasing NBM winds a bit, with
frequent gusts to around 25kts anticipated Friday.
Upper low digs and cuts off over NC/VA by tomorrow night, which
should result in a somewhat prolonged duration of wrap
around/cold conveyor and lake+terrain enhanced snow to bring
T-3" of accum to the western mtns - with a local bullseye most
likely in favored ridgetops and summits in the Laurel Highlands.
Conditions will dry out downwind of the Allegheny Front thanks
to downslope westerly flow. MinT Friday night will trend 10-20F
colder night/night with readings in the 20-30F range. Despite
the fairly robust 24hr deltaT, lows will still be +5-10F above
climo as we approach the climatological coldest part of the
winter season.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Fair and seasonable conditions appear likely Saturday, as high
pressure ridging builds into the region, causing any lingering
snow showers over the western mountains to taper off. The
pressure gradient remains fairly tight, so expect it to be
breezy. Ensemble plumes support gusts to around 30 mph.
There is high confidence of fair and progressively milder
conditions Sunday and Monday, as upper level ridging builds
over the region and surface high passes off the east coast. The
latest ECENS and GEFS both track a surface low west of Pa Monday
night into Tuesday, bringing mild conditions with a bit of
light rain. Some guidance indicates there could be enough cold
air for mixed precip at the onset, but high pressure southeast
of Pa is not favorable for holding onto cold air.
Medium range guidance is in fairly good agreement into the
middle of next week, indicating a brief period of fair weather
Tuesday night into Wednesday associated with upper level
ridging. Focus then turns to next southern stream shortwave and
associated surface low, which is progged to track west of Pa and
could potentially spread rain into the area Wednesday night and
Thursday. The southern branch of the jet will remain dominant
into next week, flooding the area with mild weather. Ensemble 2m
temp plumes suggest highs should be 10-15 degrees above average
and lows 10-20 above average.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
First modification to 00Z TAF cycle was to include several
hours (west) and up to 8 hours east, of LLWS as the core of a
south-swrly LLJ of 60KT within the 2-4 KFT AGL layer shifts
east across the region preceding a cold frontal passage. A
strong gradient in vertical speed/direction will exist at the
base of this wind core between 1-2 kft AGL.
This LLWS will especially impact FAP to airfields as cigs and
ocnl vsbys will be in the IFR range from stratus, rain and fog.
Otherwise, widespread LIFR-IFR conditions in light-moderate
rain through much of the night will improve to MVFR east of the
mtns during the day Friday.
This trend will occur following the passage of a cold front and
gusty wind shift to 270-300 degrees.
Snow and upslope flow beginning between 07-08Z Friday at KBFD
and KJST should maintain IFR over the western TAFs into Friday
night while conditions eventually trend toward VFR in the
southeast terminals by Saturday morning.
Outlook...
Sat...Continued breezy, with snow showers fading across the wrn
airspace. Wind gusts from 290-330 20-30kts.
Sun...MVFR cigs possible early west, otherwise VFR/no sig wx.
Mon...VFR. Rain possible late Monday night western 1/3.
Tue...Rain likely western 1/2.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Steinbugl
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Steinbugl
LONG TERM...Fitzgerald
AVIATION...Lambert/Steinbugl
Area Forecast Discussion
National Weather Service Dodge City KS
557 PM CST Thu Jan 12 2023
...updated aviation weather section...
.SHORT TERM...(This evening through Friday night)
Issued at 1208 PM CST Thu Jan 12 2023
18z observations are showing a large longwave trough dipping all
the way to Texas with the low pressure center near the Missouri
boot heel. At the surface a 1032 mb high is centered from South
Dakota to Texas and has pretty much cleared the area of any cloud
cover and will continue to reduce the winds towards this evening.
For tonight the main highlight in the forecast is the fog and low
cloud potential mainly from Dodge City to Hays towards sunrise.
HRRR and RAP skew-t models are showing the boundary layer
saturating around 3-4 am with light winds at the surface. HREF
probabilities this morning were hinting at areas of fog
developing starting around the I-70 corridor and then expanding
southward towards morning. There will be a subtle wind shift line
towards morning with wind switching to the west that should keep
most areas west of highway 283 free of low clouds and fog. With
the mainly clear skies outside of the fog and low wind speeds we
should have good radiational cooling as lows fall into the teens.
Friday the upper level winds will transition from the trough to a
ridge axis which will be centered over the Rockies by midday. This
will allow winds to switch to the south to southwest in the
boundary layer and 850 mb temps should warm back to 4-6(C). Once
the fog and low clouds erode we should have plenty of sunshine and
highs will range from the 40s in the east where the clouds will
hang on the longest to the upper 50s in the west where they should
have all day sun.
Friday night should be more mild as the ridge axis moves firmly
into western Kansas and winds will be south to southwest in the
boundary layer. With stronger winds this should keep temperatures
up as lows fall into the upper 20s.
.LONG TERM...(Saturday through Thursday)
Issued at 201 PM CST Thu Jan 12 2023
Main messaging of the long term will be a couple of storm systems
to highlight the first being for Sunday night and the second will
be on Wednesday.
Saturday the ridge axis will slide east and the next storm system
should reach onshore leading to a trough in the desert southwest.
Winds at the surface should increase out of the southwest with a
lee side trough and surface low developing in Colorado. With the
southwest winds and generally sunny skies highs should reach into
the upper 50s to lower 60s.
For Sunday night the long term models and ensembles are in fairly
good agreement that the main axis of the trough will be centered
in western Kansas with the main forcing and surface low tracking
through northwest Kansas. The surface low will deepen to around
994 mb by Monday morning in northeast Kansas and this should push
a cold front through the region. Winds will increase behind the
front by sunrise Monday. Overall precip chances look slim as there
could be a small mesoscale fgen band behind the front but the more
robust moisture will be further east. NBM output gave us
basically less than 15% POPs and I was fine with that idea.
The next storm system of interest looks to be next Wednesday with
all sorts of possibilities from the long term models and
ensembles. The main track would develop a closed low somewhere
from southern Colorado through northern New Mexico by early
Wednesday morning and then track east/northeast into central
Kansas by Wednesday night. GFS has the most northern track, Euro
has a little further south, and the Canadian has the farthest
south track. As a result Canadian QPF output has the most while
the Euro and GFS also give us some healthy amounts of QPF. Overall
it is still too far out to nail anything down but it is a glimmer
of hope we could be seeing some desperately needed moisture.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 554 PM CST Thu Jan 12 2023
There is an area of weak surface convergence roughly along the
highway 283 corridor, toward 12z and beyond, where the HREF and
HRRR hint at some radiational fog development. There is not a lot
of confidence in this and it may not be all that widespread
however we have included some IFR fog in the TAFS for DDC/HYS.
Other than that, the winds will remain light and variable over the
next 24 hours.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 52 29 60 / 0 0 0 0
GCK 19 53 26 59 / 0 0 0 0
EHA 21 57 29 66 / 0 0 0 0
LBL 20 57 27 65 / 0 0 0 0
HYS 16 46 26 55 / 0 0 0 0
P28 19 46 27 57 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...Russell
Area Forecast Discussion
National Weather Service Grand Rapids MI
950 PM EST Thu Jan 12 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 945 PM EST Thu Jan 12 2023
We`re watching some light precipitation over nw Lower dropping
south over the lake. Short range models keep this pcpn over the
lake tonight. However, the HRRR remains an outlier and gives a
little pcpn around 09z over the US-131 corridor. Not too confident
in this happening, although if it did, we may see light freezing
drizzle out of it, considering the dry DGZ. We`re going to
maintain very light PoPs tonight for that possibility. Otherwise,
no changes to the forecast.
&&
.DISCUSSION...(This evening through next Thursday)
Issued at 204 PM EST Thu Jan 12 2023
- Risk for flurries/freezing drizzle tonight
Low level moisture is shown to increase this evening as the
northerly flow strengthens on the backside of the departing storm.
Light precipitation has developed over Northern Lower MI based
off of radar loops. Surface temperatures were mostly in the mid 32
to 35 degree range. Northerly flow is slightly downslope for much
of our CWA and the temperature would need to drop off a few
degrees for any impacts. The 18z HRRR supports the weakening trend
to the area of precipitation dropping down from the north this
afternoon. This model run then redevelops light precipitation
later tonight with it mainly in the form of light snow
showers...with the cloud depth just reaching into the DGZ. We will
keep the POPs low for tonight...and feature mainly light snow
showers as the temperature falls below freezing. Close monitoring
will be needed this evening.
- Dry Weather Saturday into Sunday
High pressure ridges in from the west on Saturday and east of the
region Sunday. Subsidence associated with the passage of this
system will act to limit the risk for any precipitation. Moisture
profiles Saturday show the atmosphere dry through a deep layer. On
Sunday though...upper level moisture will be on the increase as
the ridge pulls east of MI. The southerly winds on Sunday will
start to advect some milder air in from the south.
- Rain arrives for Monday...locally heavy
Deep warm and moist air advection occurs on Monday with the nose
of a 30 to 40 knot LLJ along the MI/IN border. PWAT values climb
to near an inch Monday. Aloft the left front quadrant of a 250 mb
jet crosses this zone...support deep upward lift. Combining all
this supports large area of rain to move into the CWA Monday
lasting into Monday night. There is even some weakness in the
stability showing up Monday evening so the risk for a storm or two
is not zero.
- Another storm is progged for Thursday
Models are showing this next storm to be stronger than the Monday
storm. The surface pattern of high pressure over Ontario and low
pressure approaching from Illinois is favorable for at least a
period of freezing rain/wintry mix. This system will feature a
tight thermal gradient so its track will be important for
temperatures and associated precipitation types. Ensemble
forecasts still support the region getting into the warm
sector...so that would favor a transition to rain Thursday.
Trends in the model track show a further north track of the storm.
This would favor the warm sector making it into the CWA.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 615 PM EST Thu Jan 12 2023
Latest nephanalysis shows MVFR cigs across much of the Upper
Midwest. A deep upper trough is moving across the region and cigs
will increase late in the period once the trough axis moves across
the state.
We`re still watching for the potential of freezing drizzle
tonight. Best timeframe to see it would be midnight to 6 AM....if
it were to occur. One model does show quite a bit of lift in the
cloud layer and given the dry dendritic growth zone, this would
likely fall as freezing drizzle. However, other models don`t show
much of any lift. Thus, there`s a lot of uncertainty here and
didn`t feel confident enough to put it in the TAFs.
&&
.MARINE...
Issued at 204 PM EST Thu Jan 12 2023
The mixing heights will deepen tonight as the pressure gradient
tightens up. The winds at 925/850 mb are shown to increase to over
30 knots tonight. With the deeper mixing...we will likely see a
high end SCA or low end Gale event over the nearshore waters. The
winds will gradually decrease as we go through the day on Friday.
After a break in the hazardous conditions Saturday...the winds
will increase out of the south on Sunday as the next wave of low
pressure moves in. Forecast values up around 925/850 mb approach
40 knots in the warm air advection pattern. Headlines will likely
be needed then.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Gale Warning until 1 PM EST Friday for LMZ844-848-849.
Small Craft Advisory until 1 PM EST Friday for LMZ845>847.
&&
$$
UPDATE...04
DISCUSSION...MJS
AVIATION...04
MARINE...MJS
Area Forecast Discussion
National Weather Service Jacksonville FL
720 PM EST Thu Jan 12 2023
...New UPDATE...
.UPDATE...
Issued at 719 PM EST Thu Jan 12 2023
Overall, the forecast remains on track, but did introduce PoPs into
far inland SE GA as weakening showers push across the area ahead of
the main squall.
Dry, stable airmass in place will only slowly moisten as the line
of storms approaches with marginal instability developing just
ahead of the line. This should act to weaken the line as it pushes
into the far northwestern counties around 8pm, however, a strong
low level jet sliding eastward will lead to strong lower shear,
around 45-50 kts. So, the wind threat is still the primary concern
with gusts 45-65 mph possible, but a non-zero isolated tornado
threat exists for the far northwestern zones of SE GA through
around 10pm before the threat wanes. The higher end gusts will be
more likely with bowing segments along the line between 8p-
midnight.
With the dry airmass over the FL peninsula today, it will be tough
for the line to maintain intensity and should weaken into a broken
line of embedded storms as it moves southeast along and across the I-
10 corridor around midnight, as the HRRR depicts fairly well.
Despite weakening, a strong gust front 40-50 mph is possible as the
convection moves into and through the Jacksonville metro. Strong
forcing along the line will promote convection through the entire
night with the line exiting to the south and into the Atlantic
around dawn. Winds and trailing cloud cover will keep lows from
feeling the full effect of the post-frontal cold air advection
tonight, with readings spanning the upper 40s to lower 50s.
&&
.NEAR TERM...
Issued at 422 PM EST Thu Jan 12 2023
Strong to severe storms continue across portions of the southeast
states from nrn GA to central AL and southeast LA. Locally, warm
southerly flow continues with temps in the 70s to near 80, with a
weak Atlantic sea breeze at the coast keeping our local beaches
much cooler around the upper 60s to lower 70s. Some moisture is
creeping into our west zones with additional high clouds and a low
level cumulus field. The deeper mixing is resulting in a few gusts
of about 30 mph, mainly inland southeast GA at this time. VWP from
KVAX shows 25-40 kt at about 1-2 kft and little directional
shear.
Tonight, as the front nears the area, a narrow corridor of instability
develops but still remains fairly low with surface based CAPE of
about 200-600 J/kg. Tallahassee sounding at 18z reveals a lot of
dry aloft but shear of 45-50 kt. Based on guidance from the HRRR,
the convection is forecast to be in a broken line, with some
additional convection out ahead of it. The time frame is from
about 8-9 PM entering our northwest zones of southeast GA, to
the JAX metro area around 1-2 AM, and then southeast zones about
3-5 AM. Given the instability and the shear values, there is
potential for strong to severe wind gusts of 45-60 mph as the
convection moves in, with the threat over most of southeast GA and
also the Suwannee Valley area. Tornado potential is much lower
than the wind threat, and is mainly located northwest of a line
from Jesup GA to Statenville GA, with some meso-vortices possible
in the line. Still some potential for strong gusty winds over the
reminder of the forecast area late tonight given the pressure
perturbation of the front and remaining convection that pushes
through, with estimated gusts of up to 35-45 mph. Precip amounts
will be fairly low, less than 2/3rds of an inch. Temps will drop
toward about 48-55 deg toward early morning.
&&
.SHORT TERM...
(Friday through Saturday night)
Issued at 422 PM EST Thu Jan 12 2023
Strong cold front will be moving through the southeast part of
the forecast area Friday morning, and push east of the area
by about noon -1 PM. Ongoing convection expected early Friday
along and ahead of the front, with gusty winds and periods of
brief moderate to heavy rainfall. Strong cold advection will
continue in the wake of the front, with strong troughing aloft
digging down over the southeast US, with the 500 mb height contour
down to 5400 meters over parts of nrn GA. Spokes of vorticity
will rotate through the trough and allow for lingering low level
moisture to continue. Given the cold advection pattern, temps will
be fairly steady, and drop more noticeably by mid to late
afternoon as the sun angle lowers. Brisk northwest flow near 15-25
mph expected. For some areas, the high temperature may be in the
morning. Highs are forecast in the mid 50s northwest zones to
lower 60s southeast zones. Friday night. strong cold advection
continues with still a good chance of partly cloudy skies owing to
moisture rotating on the back side of the mid/upper level trough
which should be pushing offshore by sunrise Saturday. Lows are
forecast to bottom out mainly in the mid 30s, with a wind of about
10-15 mph into the night. This will support a short window of
possible wind chill advisory (at or below 25) for northeast FL,
with apparent/wind chill in the 20s.
Saturday, sfc high pressure system moves a bit closer to the
forecast area during the day...to the lower to mid MS valley
around 1029 MB. The model progs show diminishing low level
moisture so increasing sunshine expected. Despite more sun, cold
advection continues with a brisk northwest wind. Highs in the
upper 40s to lower 50s anticipated at this time, which is some
10-15 deg below normal.
Saturday night, the pressure gradient in the area loosens further
as the high pressure system moves to the AL area by late night.
Winds will diminish further overnight to about 5 mph or less.
Some breezier wind is possible near 5-10 mph at the coastal areas
due to enhanced drainage flow from the high pressure and the cold
airmass. With skies now clear by this time everywhere, a light
freeze is anticipated inland areas in the upper 20s to about 30
deg. Closer to the coast/I-95 areas, the low temps may be just
above freezing around 33-37 due to the drainage flow. Having said
that, winds could drop in sheltered areas in these areas to
realize a brief freeze.
&&
.LONG TERM...
(Sunday through next Thursday)
Issued at 422 PM EST Thu Jan 12 2023
A shortwave ridge will move over the region Sun-Mon in the wake
of the trough from the cold snap. Sfc high pressure will also
move across the region, with some return flow developing late
Monday as the high begins to shift offshore to the southeast.
As the ridge aloft moves out, another shortwave trough approaches
and moves across our nrn zones Monday night into Tuesday but much
of the energy is north of the area. A frontal boundary associated
with the weak shortwave trough begins to stall across parts of
central GA and SC. The shortwave system moves out of the region
Tuesday afternoon and evening and ridging builds back over the
area as a stronger shortwave trough moves in over the Plains/central
U.S. Wed-Thu time frame. Any lingering front over central GA
pushes back north by early Wed night.
Sunday...After a frosty start, sfc high pressure and quiet weather
expected with below normal temp again with highs about 55-60 degs.
Sunday night, clear skies and calm winds will lead to quick drop
in temps into the evening hours, with lows overnight in the lower
to mid 30s. A freeze and frost looks probable in a good part of
the area.
Monday...Some increase in high clouds expected with temps moderating
closer to normal in the 60s, after the cold morning. More mild lows
Monday night in the 40s, with a few upper 30s possible inland.
Tuesday/Wednesday...the return flow and lingering moisture from
the shortwave will allow for partly cloudy skies at times. There
may be enough moisture for a few showers across the north zones
due to the nearby frontal system to our north and weak forcing
aloft. Otherwise, more mild temps with highs in the lower/middle
70s on Tuesday and into the mid/upper 70s on Wednesday as
southwest flow increases.
The next frontal system approaches the region on Thursday so we
introduced a chance of showers with this system though uncertainty
is high given some model discrepancy at this time frame. Temps
continue warm ahead of the front in the mid to upper 70s.
&&
.AVIATION...
(00Z TAFS)
Issued at 616 PM EST Thu Jan 12 2023
VFR conditions will continue with predominant southwesterly winds
between 6-12 kts through around midnight before a line of
moderate to strong, but generally weakening, showers and embedded
storms will quickly push southeastward through the regional
airfields. Expect line to reach SSI first (near 05z) and then the
JAX Metro and GNV around 07z, and lastly SGJ around 08z. This line
will bring the potential for strong wind gusts in excess of 35
kts along with a drop in vsby to at least MVFR and possibly LIFR
in stronger convection for about an hour or so as it passes. This
line will move quickly through each terminal entering and exiting
within an hour window with trailing showers likely behind the
primary front. Winds will shift WNW and trend northwesterly in the
wake of the cold front driving the storms. High confidence in
wake low stratus between 2-3 kft to prevail through most of the
day Friday with NW gusts 25-30 kts during the afternoon.
&&
.MARINE...
Issued at 422 PM EST Thu Jan 12 2023
There were a few changes in the updated marine forecast but
generally have SCA headline starting tonight offshore water and
have the SCEC headline nearshore. The SCA is expanded to the
nearshore waters on Friday as the strong offshore flow will be in
full force, with potential for gale force gusts going into Friday
night. With collaboration with neighboring office, opted to not
go with gale watch due to somewhat marginal nature of the gale
force wind gusts. SCA continues into Saturday but ends in all
waters Sunday morning after ~11Z, as high pressure system moves
in from the west.
Rip Current Risk: Surf near 2 ft and winds are near parallel or
slightly southeast this aftn, resulting in a low risk.
&&
.FIRE WEATHER...
Issued at 422 PM EST Thu Jan 12 2023
South-southwest surface and transport winds will remain breezy through
sunset, which will result in high daytime dispersion values rest
of today. Minimim relative humidity values just above 25 percent
today but mainly 28-35 percent range rest of the afternoon across
inland northeast FL to around Waycross and Jesup, GA. Elevated
fire weather conditions continue across part of the area rest of
the aftn. Rainfall amounts with the front tonight expected to be
under 2/3rds of an inch. Breezy southwest then west surface and
transport winds overnight will shift to northwest by sunrise.
Gusty northwesterly surface and transport winds will prevail on
Friday, creating good to marginally high dispersion values.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 49 56 33 51 / 100 0 0 0
SSI 53 61 37 51 / 100 0 0 0
JAX 52 61 34 52 / 100 10 0 0
SGJ 54 63 36 51 / 90 40 0 0
GNV 52 61 33 53 / 100 20 0 0
OCF 54 62 34 53 / 90 30 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...Small Craft Advisory from 10 AM Friday to 9 PM EST Saturday for
AMZ450-452-454.
Small Craft Advisory until 7 AM EST Sunday for AMZ470-472-474.
&&
$$
Area Forecast Discussion
National Weather Service Melbourne FL
1019 PM EST Thu Jan 12 2023
...New UPDATE, MARINE, AVIATION...
.UPDATE...
Issued at 1015 PM EST Thu Jan 12 2023
Dry and pleasant conditions are in place across the area this
evening as temperatures fall into the 60s. A strong cold front is
now draped across AL/GA/north FL as rain showers and thunderstorms
continue to progress southeastward ahead of the front. The latest
RAP analysis depicts a tightening pressure gradient over north-
central Florida tonight, and surface winds are expected to
increase in response early Friday morning.
PW values from the 23z XMR sounding of 0.74" are in line with the
latest model guidance, which brings a band of drier air across
the Florida Peninsula through the early morning hours, ahead of
the front. Moisture quickly increases along the cold front as it
pushes into east central Florida, with a narrow ribbon of 1.4" to
1.6" PW suggested by CAMs. Rain chances increase after 3 AM for
locations along and north of Interstate 4, followed by the Orlando
Metro/Space Coast after 5 AM, and the Treasure Coast/Lake
Okeechobee region after 7 AM. Sufficient frontogenetic forcing
will allow showers to persist as the front moves south through the
area. Model soundings are lackluster prior to 9 AM with regard to
instability, but a few rumbles of thunder cannot be ruled out
among any organized activity through mid morning.
&&
.MARINE...
Issued at 1015 PM EST Thu Jan 12 2023
Tonight (modified previous)...Boating conds gradually deteriorate
as southwest winds increase near 20-25 knots across the
Volusia/Brevard offshore waters after midnight with 15-20 knots
across the south. Seas will build up to 6 ft well offshore Volusia
late tonight but remain suppressed 2-3 ft near the coast.
&&
.AVIATION...
(00Z TAFS)
Issued at 1015 PM EST Thu Jan 12 2023
VFR thru 07z-08z expected. SW winds increasing, turning WSW along
and behind a strong cold front after 12z. TEMPO now included for
most sites except the Treasure Coast for -SHRA and MVFR CIGs. A
few isolated TS cannot be ruled out during the frontal passage
after 14z, mainly for sites south of MCO. TEMPO may be needed in
future TAFs for Treasure Coast sites.
Gusty WNW winds behind the front may reach 20-25 kts during the
afternoon. VFR gradually resumes toward the end of the TAF period
into Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 58 65 38 54 / 60 60 0 0
MCO 57 68 39 55 / 30 70 0 0
MLB 57 71 40 56 / 0 70 0 0
VRB 56 73 40 57 / 0 70 0 0
LEE 57 65 37 53 / 70 50 0 0
SFB 58 67 38 53 / 50 70 0 0
ORL 59 66 39 54 / 40 70 0 0
FPR 57 74 41 57 / 0 70 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory from 4 AM Friday to 10 PM EST Saturday for
AMZ550-552.
Small Craft Advisory from 10 AM Friday to 4 PM EST Sunday for
AMZ555.
Small Craft Advisory until 4 PM EST Sunday for AMZ570-572.
Small Craft Advisory from 4 AM Friday to 4 PM EST Sunday for
AMZ575.
&&
$$
Schaper/Sedlock
Area Forecast Discussion
National Weather Service Marquette MI
710 PM EST Thu Jan 12 2023
.SHORT TERM...(Through Tonight)
Issued at 234 PM EST THU JAN 12 2023
Water vapor imagery and RAP analysis mid-level troffing extending
from near James Bay across far northern Lake Superior to northern
MN. Deep moisture, weak synoptic forcing and 850mb temps nearing
-10C per latest RAP analysis are supporting some light lake enhanced
snow today across western into n central Upper MI. There have been a
few bands of briefly heavier snow streaming into Marquette County.
While there was some sun in Luce County earlier today thanks to
downsloping off of the Canadian Shield breaking up clouds, abundant
cloud cover has otherwise dominated once again. Current temps are in
the 30s F, but temps have slipped into the upper 20s F in portions
of nw Upper MI.
Conditions should be fairly steady state into the evening under deep
moisture and weak forcing as mid-level trof axis drops s. Since
850mb temps may fall another degree or two C, lake enhanced snow
should expand/increase a bit before a transition to pure LES. DGZ
should also slip into the upper portion of the lake induced
convective layer, but that will occur as deeper moisture begins to
depart with passage of mid-level trof. Overnight, moisture depth
ends up at 3-5kft, lowest w. As a result, not expecting much in the
way of snow accumulation tonight. Maybe an inch or 2, greatest in
the high terrain where upsloping northerly winds add a boost. Under
continued cloud cover, temps should only fall to the mid teens to
mid 20s F.
.LONG TERM...(Friday night through Thursday)
Issued at 328 PM EST THU JAN 12 2023
Key Messages:
-Light lake effect lingers Friday
-Quiet weather for weekend
-Next precip maker Monday/Tuesday, potentially messy
By 12Z Friday, a ridge will be building in overhead. This will keep
in light northerly flow, backing to the northwest and eventually
west/southwest into Friday evening. A chance for light lake effect
flurries/light snow showers lingers mainly in the northerly flow
snowbelts, but our airmass is turning increasingly drier. Thus, any
accumulations will be light, with more breaks in the clouds across
much of the area apart from lingering lake clouds closer to
Superior. Saturday stays dry, and temperatures to come in slightly
warmer given increasing heights, potentially a few more breaks in
the clouds (at least for the first part of the day), and a shift
over to southwest flow. The ridge really starts to shift eastward
into Sunday, and increasing midlevel southwest flow will touch off
better WAA. We may start to see high-level clouds streaming into the
area Sunday as a trough and associated surface low over the southern
plains starts to track northeast into the Midwest.
Into Monday, the deepening low pressure system continues to move
into the Midwest, with a surge of WAA and a good amount of moisture
(PWATs increase well above normal, with a potential for us to also
tap into some Gulf moisture amid robust southerly flow). This should
bring in a round of synoptically forced precipitation by sunrise. So
far, our best chances are over the eastern UP, with good agreement
amongst the latest guidance for the system to track from central, or
possibly northern WI into the LP. Some lake enhancement upwind of
Lake Michigan may also lead to locally higher precipitation chances.
A challenge with Monday/Mon night will be determining just how far
northward this system will make it before exiting to our east into
Tuesday. Some of the guidance does take this a little more northward
into WI than others. This will have a big impact on precip type, as
a more southerly track would result in more snow, and a more
northerly track better chances for rain or a wintry mix. Current
forecasts favor a warmer scenario. Model soundings across much of
the UP Monday afternoon show a nearly isothermal layer right around
the freezing point from the surface up to around 5kft. With high
temperatures in the mid/upper 30s, this could point to a period of
mainly rain or a rain/snow mix. Will not rule out some pockets of
freezing rain in the chilliest spots. Precipitation starts to taper
off overnight into early Tuesday as a weak cold front moves through
and a ridge starts to build in. Amid northwest flow, lingering lake
effect flurries and snow showers are possible, but this should be
fairly light with temperatures aloft not turning particularly chilly
and drier air working in.
Tuesday night into Wednesday turns dry, but yet another Southern
Plains trough/surface low will start to move in Thursday. This takes
a similar track to the Mon/Tue system, though shifted slightly to
the south, and guidance is showing this to be rather deeper than the
previous system. Thus, we have a potential for a more significant
precipitation event, but precip type and accumulations will remain
highly sensitive to the track of the system.
Otherwise, temperatures continue to run warm the rest of the
forecast period with ensembles showing 850mb temperatures well above
normal. Friday continues to look the closest to "normal" with
temperatures peaking in the 20s Friday afternoon before falling back
into the teens and single digits overnight (depending on the level
of clearing). Afternoon highs climb into the 30s Saturday and
Sunday, and may come in well into the mid and upper 30s the
remainder of the week. Lows the rest of the forecast period range
generally in the 20s to lower 30s.
After this warm spell, several ensemble runs are bringing negative
temperature and 500mb height anomalies for the last week of January,
so there may be hope for cooler air ahead!
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 709 PM EST THU JAN 12 2023
Periods of lake effect snow showers will persist tonight in the
upslope northerly winds and colder air. The inconsistency of the
snow showers will result in some fluctuation in flight categories,
but IFR will be the most prevalent at SAW/IWD with periods of LIFR.
CMX, however, is expected to be around MVFR/IFR into tonight before
visibilities deteriorate to IFR/LIFR early tomorrow morning.
Northerly winds will be strong at CMX and SAW with sustained speeds
as high as 18 to 20 kts, gusting to 25 kts.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 328 PM EST THU JAN 12 2023
Northerly winds continue to gust to around 25 to 30kts especially
across the central portions of Superior this evening and tonight.
Meanwhile, across the western portions of the lake, wind gusts
around 20 to 25kts fall back below 20kts overnight. Winds fall back
below 20kts across the rest of the lake throughout the day Friday,
and remain below 20 knots until Saturday night. Southerly gusts will
then pick up to 20 to 25 knots over the east half of the lake.
Sunday, southerly gusts may occasionally reach 25 to 30 knots, but
decrease to 20 to 25kts Sunday night before finally falling back
below 20kts Monday evening. Winds remain below 20kts through Tuesday
morning before increasing to 20 to 25kts into Tuesday evening.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...LC
AVIATION...TDUD
MARINE...LC