Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/26/23
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
857 PM MST Wed Jan 25 2023
...New UPDATE...
.UPDATE...
Issued at 856 PM MST Wed Jan 25 2023
Updated to add a Freezing Fog Advisory for tonight for the Central
Highlands. Updated ZFP and grids sent.
&&
.SYNOPSIS...
Issued at 206 PM MST Wed Jan 25 2023
Snow showers in the northern mountains and eastern plains will
continue this afternoon before tapering off overnight. Tonight will
be cold with lows generally in the teens and single digits but
dipping down well below zero in northern mountain valleys. Thursday
through Sunday will be dry with temperatures warming each day but
remaining below seasonal averages. Another storm may impact the
state Monday through Wednesday next week, potentially bringing
precipitation and strong winds.
&&
.SHORT TERM...
(This evening through Thursday night)
Issued at 206 PM MST Wed Jan 25 2023
Instability is on the uptrend this afternoon with daytime heating
(relative) and given cold air advection continuing in the mid levels
of the atmosphere. Showers are increasing in coverage across the
northern mountains and continue across the eastern plains, with a
localized and quick 1" of snow possible. Snow showers will diminish
rapidly this evening per the latest HRRR and HREF. Impressive
upstream temperatures showed up in the 12Z upper air data this
morning, with -14C at 700mb at Grand Junction and Salt Lake City and
-33 and -31C at 500mb respectively at those sites. Needless to say,
tonight will be the coldest of the forecast period, with well below
normal low temperatures in the single digits to negative single
digits across much of northern and western NM. Lows in the teens
will be common elsewhere. Another cold day is on tap Thursday, with
high temperatures forecast 15-20 degrees below normal despite plenty
of sunshine. Given some lower elevation snow melt Thursday and
rising pressure heights forecast, freezing fog may become a more
likely event compared to tonight. Freezing fog is currently not in
our forecast due to lower Forecaster confidence at this time.
&&
.LONG TERM...
(Friday through Tuesday)
Issued at 206 PM MST Wed Jan 25 2023
The development of a surface low in northeast New Mexico in the wake
of an exiting trough will increase winds up to around 25 mph along
the east slopes of the Sangre de Cristo mountains and central
highlands Friday night. Dry westerly flow on Saturday and Sunday
will gradually warm temperatures but keep them a few degrees below
average during the day and near average at night. On Monday, a
longwave trough is expected to slide down the California coast.
Veering winds will help to warm daytime temperatures a few degrees
as southerly winds pick-up statewide. Large-scale lift and moisture
advection out ahead of the trough will begin to increase
precipitation chances in the northwest corner of the state.
After Monday, guidance begins to diverge on this storm`s track.
Cluster analysis shows a few potential scenarios, the most likely of
which slides the trough eastward across the desert southwest into
the state on Tuesday. Western New Mexico would be most favored for
precipitation within this scenario, but the entire state would
likely see an uptick in winds out ahead of the trough. Even with
this storm track, moisture will not be plentiful as evidenced by
GEFS and EPS ensemble means showing only average to below average
PWATs over the state on Tuesday and Wednesday. Another, less likely,
scenario has the low diving down into northern Mexico and only
bringing light precipitation to the southern portion of the CWA. The
least likely scenario would lift the California low into the central
Rockies, limiting precipitation to only the northern mountains. The
current forecast best reflects the first scenario with increasing
PoPs Monday night through Wednesday morning in western and central
New Mexico and an uptick in winds statewide Monday and Tuesday.
&&
.AVIATION...
(00Z TAFS)
Issued at 415 PM MST Wed Jan 25 2023
Sct showers moving sewd over the ne third to half of NM to
diminish after 26/01Z as instability decreases. Upper trough axis
to be oriented from west to east over far nrn NM around 26/06Z to
pass swd over NM through 25/21Z bringing drier air to the region.
Low level moisture to also decrease but lcl low clouds and fzfg
may develop aft 25/06Z and persist through 15Z in vicinity of
snow covered areas.
&&
.FIRE WEATHER...
Issued at 206 PM MST Wed Jan 25 2023
Critical fire weather conditions are not expected through at least
the next seven days. Cold conditions will persist through the end of
the week with below normal temperatures and a mixed-bag of poor to
good ventilation across the area. Winds will increase some over the
weekend with the passage of a shortwave trough and across the
eastern plains with a backdoor cold front. The next storm system is
forecast to impact the area from early to mid next week, bringing
stronger winds, colder temperatures, and chances for wetting
precipitation.
&&
.PRELIMINARY POINT TEMPS/POPS...
Farmington...................... 5 30 9 33 / 0 0 0 0
Dulce........................... -2 29 2 34 / 0 0 0 0
Cuba............................ 4 27 6 33 / 0 0 0 0
Gallup.......................... 3 30 5 36 / 0 0 0 0
El Morro........................ 4 29 6 36 / 0 0 0 0
Grants.......................... 3 32 5 42 / 0 0 0 0
Quemado......................... 5 29 5 41 / 0 0 0 0
Magdalena....................... 13 30 12 41 / 0 0 0 0
Datil........................... 6 28 7 40 / 0 0 0 0
Reserve......................... 9 37 9 50 / 0 0 0 0
Glenwood........................ 19 43 17 51 / 0 0 0 0
Chama........................... -5 24 1 33 / 20 0 0 0
Los Alamos...................... 11 28 14 36 / 10 0 0 0
Pecos........................... 9 31 14 40 / 20 0 0 0
Cerro/Questa.................... 0 25 6 36 / 20 0 0 0
Red River....................... -8 20 1 34 / 30 0 0 0
Angel Fire...................... -17 22 -11 33 / 20 0 0 0
Taos............................ -4 26 1 35 / 10 0 0 0
Mora............................ 3 30 11 46 / 20 0 0 0
Espanola........................ 8 34 11 40 / 10 0 0 0
Santa Fe........................ 11 29 15 36 / 10 0 0 0
Santa Fe Airport................ 7 32 12 37 / 10 0 0 0
Albuquerque Foothills........... 20 35 20 40 / 0 0 0 0
Albuquerque Heights............. 18 36 18 41 / 0 0 0 0
Albuquerque Valley.............. 14 39 14 43 / 0 0 0 0
Albuquerque West Mesa........... 17 37 17 42 / 0 0 0 0
Belen........................... 14 39 13 42 / 0 0 0 0
Bernalillo...................... 17 37 17 43 / 0 0 0 0
Bosque Farms.................... 11 39 12 43 / 0 0 0 0
Corrales........................ 17 37 16 43 / 0 0 0 0
Los Lunas....................... 12 39 11 42 / 0 0 0 0
Placitas........................ 17 33 18 38 / 0 0 0 0
Rio Rancho...................... 18 36 18 42 / 0 0 0 0
Socorro......................... 17 38 14 43 / 0 0 0 0
Sandia Park/Cedar Crest......... 15 29 16 34 / 0 0 0 0
Tijeras......................... 13 32 15 36 / 0 0 0 0
Edgewood........................ 11 31 13 37 / 5 0 0 0
Moriarty/Estancia............... 8 33 10 39 / 5 0 0 0
Clines Corners.................. 8 28 11 36 / 20 0 0 0
Mountainair..................... 12 32 13 38 / 0 0 0 0
Gran Quivira.................... 13 34 13 38 / 0 0 0 0
Carrizozo....................... 18 38 18 42 / 0 0 0 0
Ruidoso......................... 12 31 15 40 / 5 5 0 0
Capulin......................... 3 30 9 41 / 20 0 0 0
Raton........................... 0 34 6 44 / 20 0 0 0
Springer........................ -2 37 6 49 / 20 0 0 0
Las Vegas....................... 4 34 10 49 / 20 0 0 0
Clayton......................... 14 40 18 49 / 0 0 0 0
Roy............................. 7 37 13 47 / 20 0 0 0
Conchas......................... 13 43 14 52 / 20 0 0 0
Santa Rosa...................... 14 40 20 48 / 20 0 0 0
Tucumcari....................... 12 42 14 51 / 10 0 0 0
Clovis.......................... 15 39 18 45 / 10 0 0 0
Portales........................ 13 41 18 47 / 0 0 0 0
Fort Sumner..................... 17 41 18 49 / 20 0 0 0
Roswell......................... 21 43 17 53 / 0 0 0 0
Picacho......................... 17 36 16 48 / 0 5 0 0
Elk............................. 14 33 12 50 / 0 5 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
Freezing Fog Advisory until 8 AM MST Thursday for NMZ223.
&&
$$
Area Forecast Discussion
National Weather Service La Crosse WI
536 PM CST Wed Jan 25 2023
.DISCUSSION...(Tonight through Wednesday)
Issued at 200 PM CST Wed Jan 25 2023
Key Messages:
- Light snow chances continue through into the weekend. Light to
minor accumulations expected.
- Winter cold returns this weekend, sticks around for the start of
February. Wind Chill Advisories might be needed from time to time.
* LIGHT SNOW PERSISTS TONIGHT/THU MORNING: minor additional accums
One shortwave a loft will ease east/southeast across IA tonight and
then northern IL Thu morning. Another shortwave then drops southeast
across WI also during the morning hours. Meanwhile, a weak sfc
trough will continue to hang westward of its parent low also exiting
east. RAP bufkit soundings show enough saturation (and deep enough
for ice) to support continued areas of light snow tonight into Thu
morning, likely exiting east for the afternoon. As has been the case
of late, QPF is meager and so will the resulting snow output. A few
more tenths here and there, potentially adding up to around an
additional inch for some locations.
* SNOW THU/NIGHT-FRI: more light to minor accumulations
Perkier shortwave (compared to today) still on track to spin across
the northern plains Thu evening, dropping across the upper
Mississippi river valley overnight through Fri morning. Good low
level warming leads the shortwave in, evidenced via 850 mb warm air
advection and isentropic upglide on the 275:290 K sfcs. Fgen is very
narrow in a north-south orientation, along the shortwave`s
associated sfc cold front. With plenty of saturation to work on,
expect a broad areas of light snow to quickly work west-east across
the forecast area. Fgen might support small banding, but not
appreciably so. In addition, as the shortwave shifts east, GFS/NAM
bufkit soundings show some potential for convective showers with
instability in the near sfc layer. With no tap to any southerly
moisture, QPF remains meager and thus snow amounts will also be on
the lighter side - generally looking at around 1".
* SAT SNOW? higher chances favored south of I-90, perhaps a few
inches.
The GFS and EC remain in good agreement with sliding an elongated,
west-east running piece of upper level energy from the southern
rockies to across portions of the region Sat. Consistent signal from
the models. However, placement and thus where the greater snow
chances lie, continues to vary.
Latest deterministic runs of the GFS and EC show a slight shift
northward with shortwave/qpf, favoring chances from at least I-90
south. Digging into the ensembles, about 1/2 of the GFS members keep
the shortwave just south of the forecast area (little to no snow
threat) while the bulk of the EC`s 50 members side with the
deterministic run. This is a change from previous runs of the EC
which leaned more into a southern track. While confidence in the
northward extent of the snow chances remain low due to models
shifts, its higher in chances along/south of I-90, where run to run
consistency within and between the models has been highest. Will
hold with the model blend for chances. As for amounts, the west-east
orientation and time/residence could produce a bit more snow than
the systems of the work week, but QPF still on the lower end. A few
inches on the top end favored right now.
* COLD ON THE WAY: jack frost pops in this weekend, hanging around
through the start of Feb. Wind Chill Advisories possible.
Cold Canadian air starts flowing in post the Friday system, and
temps are going to tumble. At 850 mb they are looking to drop from
around -5 C at 12z Fri, to -15 C by 12z Sun. Not much movement until
potentially another, even colder surge for the following weekend.
The GFS remains the more enthusiastic model with the amount of cold,
but both the GFS/EC point to sub zero lows and single digits/teens
for highs. It should be noted, as we work into the later part of
next week there is a fair amount of spread in both models` ensemble
members, with the deterministic running on the very cold end (lower
10%). A trend to watch.
There doesn`t look to be any periods of higher/stronger winds for
next week, but with temps so cold, even a 10 kt wind will cause some
problems. A few late nights/mornings wind chills in the -20s are
looking likely, and could have the need for a few Wind Chill
Advisories at times for the new week - perhaps as soon as Sunday
morning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 536 PM CST Wed Jan 25 2023
A northern stream short wave will continue to produce light snow
as it moves east across the Upper Mississippi River Valley
tonight. This snow will produce IFR/MVFR visibilities through
26.07z at KRST and 26.09z at KLSE. Snowfall amounts will likely
range from 1 to 2 inches at the TAF sites.
IFR/MVFR ceilings will persist into Thursday morning and then
become VFR on Thursday afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...Rieck
AVIATION...Boyne
Area Forecast Discussion
National Weather Service Boston/Norton MA
1006 PM EST Wed Jan 25 2023
.SYNOPSIS...
Snow arrives late this afternoon into early evening, before changing
over to heavy rain fairly rapidly from south to north tonight and
ends early Thursday morning. Gusty winds accompany this storm
through Thursday. Tranquil weather Friday and Saturday with
temperatures slightly above late January normals. A more active
pattern then develops early to mid next week with the potential
for a series of frontal system to affect Southern New England.
Specifics still aren`t clear, but the weather pattern favors
mixed wintry precipitation or rain.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
1005 PM Update:
Winter Weather Advisory was canceled for northern RI/CT along
with the southern Pioneer Valley of MA. Obs have shown warming
conditions that have changed any SN/FZRA to RA. The advisory
does continue through 06z for portions of northeast, central and
western MA. In addition, made a slight modification to the near
term temperatures, blended in the latest HRRR with the current
forecast. Otherwise the forecast update from 7pm remains on
track. See prior discussion below.
---------------------------------------------------------------
705 PM Update:
Areas of light precip have broken out across all of SNE at this
hour, with light snow across the interior or snow mixed with
rain across eastern and southeast MA and into RI. Radar mosaic
shows an area of drier air across interior New England which
has resulted in a lull in accumulating snow. However the 18z
guidance and recent few HRRR runs were steadfast in filling this
area back in between 23-01z and that does appear to be taking
place. Kept the winter weather advisory going but thinking more
steady light snow with visibility probably no worse than 3/4SM
in the more persistent snows; there just isn`t the snow
microphysical parameters at play for heavier type snows with
the stronger lift lying below the dendrite growth layer. In
eastern MA and RI, there is not much time left for accumulations
as dewpoints are rising and temperature should also rise
considerably into the late evening and overnight.
At least as much of a concern to the light-accumulating snow is
the heavy rain for the late evening into the pre-dawn hrs
especially for eastern CT, RI and eastern/southeast MA. Overall
no significant change to the forecast thinking (mentioned below)
regarding the heavy rains. A few river flood warnings are
already active for the Wood, Pawcatuck and Pawtuxet Rivers and
fast responses on smaller creeks and streams in SE MA, RI and
eastern CT should also be expected. Have to see how close the
heavy rain axis makes it into the Greater Boston area; as of now
the greatest confidence for where the heavy rain axis may lie is
just south into the eastern CT, RI/Greater Providence area and
into adjacent SE MA. While we`re not expecting a significant or
widespread flooding problem, overnight drivers and early-
morning commuters in these areas will need to be prepared for
difficult driving conditions as well as the risk for street
flooding and hydroplaning.
SE/S winds have been slowly picking up with some gusts across
the south coast now in the 25 mph range. Core of the SE low
level jet still has yet to arrive but the trend will be upward
with the strongest SE/S gusts for the overnight, nearly in
lockstep with the heavier rain.
Previous discussion from 430 PM:
* Multi-Hazard Storm later today and especially tonight
* Low risk of isolated flash flooding in eastern CT/RI and southeast
MA late tonight
Tonight...
1) Snow: At 4 pm snow overspreading CT, western-central MA and into
RI, moving rapidly northeast. Limiting factors for snow
accumulations include parent low tracking into the eastern Great
Lakes and antecedent airmass over SNE is only marginally cold enough
to support snow. Thus, WAA will quickly modify this airmass with
snow changing over the rain fairly quickly from south to north,
except along the immediate south coast, where mainly rain is
expected. There will be an hour or two of moderate to perhaps
briefly heavy snow thru 00z across CT/RI and eastern MA. After 00z,
steady/accumulating snow will be confined to western-central MA and
then exit northern MA by midnight. Short duration event combined
with lift in the DGZ and marginal temps will limit snow
accumulations to a coating to 2 inches across northern CT, northwest
RI and into the I-495 corridor of eastern MA. Less snow south and
east into the I-95 corridor to the coastline. 2-4" along and north
of I-90 and west of I-495 to the MA/NH/VT border. Thus, winter
weather advisory remains posted for this region. Given marginal
surface temps, greatest risk for snow covered roads will be across
the higher elevations of Worcester County and the Berkshires.
2) Heavy Rain: impressive s/wv trough with attending 150 kt jet
streak moving up the eastern Seaboard tonight, will be accompanied
by anomalous PWATs of 1.25 inches, which is +4 sigma for late Jan!
This induces secondary low pressure developing along/near the I-95
corridor from PHL to BOS from 06z-12z. This is also accompanied by
75 kt low level southerly jet, with the nose of this jet along the I-
95 corridor. Thus, strong jet dynamics acting on anomalous moist
airmass results in widespread 1-2 inches of qpf, heaviest amounts
across eastern CT-RI into southeast MA. Isolated higher amounts are
possible in this area, as dry slot approaches 06-12z, steepening mid
level lapse rates and combining with some low level instability (as
dew pts climb into the low 50s), convective elements may develop,
such as a broken fine line of low top convection. Some of the hi res
guidance, such as the NAMnest generating a swath of 4-5" of rain
from eastern CT into RI and southeast MA. Some of the global
guidance such as the EC, offering close to 3" in this area.
Therefore, low probability of isolated flashing flooding 06z-12z
across eastern CT/RI and southeast MA. This could impact
the early morning commute. Therefore, flood watch remains posted.
3) Strong Winds: strong low level southerly jet up to 75 kt moves
across the south coast 06z-09z. Model soundings have notable low
level inversion, but this erodes somewhat as surface temps rise into
the low 50s late tonight/early Thu morning. Also, heavy rain with
embedded convective elements could increase the wind threat.
Therefore, we expanded the wind advisory one more set of zones
northward to include Providence eastward into Bristol and Plymouth
counties.
4) Coastal Flooding: See coastal flood section at the bottom of this
discussion.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
430 PM update...
Highlights...
* Leftover heavy rain/standing water from overnight may impact the
early morning commute in RI & southeast MA
Any showers at daybreak will over eastern MA and moving rapidly
offshore. However, if isolated 3+ rainfall materialize overnight
across eastern CT/RI and southeast MA, could be quite a bit of
standing water on area roadways impacting the early morning commute.
Then sunshine develops behind the front later in the morning, but
cyclonic flow aloft combined with steepening low level lapse rates
will result in clouds filling back in. Strong cold air advection
with 850 mb temps falling from +7C in the morning (surface temps in
the low 50s at daybreak across southeast MA) to -7C by late in the
day. Low prob a few snow showers or flurries from LES spill over the
Berks into the region. Otherwise, falling temps and blustery with
west winds 15-25 mph, gusting up to 35 mph. Temps falling thru the
40s and 30s during the day, along with colder wind chills.
Thursday night...
Dry and seasonably cold, but diminishing winds as weak ridge of high
pressure advects into SNE from west to east. Lows in the 20s for
most locations.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
430 PM update...
Highlights:
* Mix of sun and clouds, but dry and tranquil weather Fri and Sat.
Temps slightly above seasonable.
* Unsettled weather pattern late weekend into midweek with series of
frontal systems to affect the area. Specifics are uncertain at
this time but pattern favors mixed wintry precip types and/or rain.
Details:
Friday and Saturday:
High pressure in place on Fri offering dry weather and a mix of
clouds and sun. Will be on the cooler side but still above normal
for this time of year with highs in the mid to upper 30s.
Increasing clouds ahead of a Clipper type low for Fri night and
continuing into Sat; however the Clipper itself is pretty starved
for moisture and also translates to our north and west. As such, its
only influence will be increasing SW breezes (gusts 25-30 mph)
during the day on Sat, then decreasing by the evening. Lows Fri
night in the upper teens north to mid/upper 20s (around freezing
near Cape Cod/Islands). For Sat under some cloud cover, highs mainly
in the lower to middle 40s with lows mainly in the 20s to near
freezing.
Sunday through Tuesday:
Today`s 12z ensembles and deterministic models all generally agree
on the mid-level pattern in this period. This pattern features
slight amplification to a mid-level ridge near the Gulf of Mexico or
Gulf Coast states. An initially active northern stream of the jet
(driven by shortwave energy rotating southward from amplifying ridge
into Alaska/-EPO type pattern) then become split as some of this
energy digs into the SW CONUS toward early next week. This creates
an enhanced WSW mid-level flow/preferred storm track, with
indications for one or multiple disturbances moving ENE in the WSW
flow aloft into early to mid next week. Hate to use the term
"temperature battle ground", but that`s pretty much what it is with
frigid air on the northern fridge of the storm track and mild
temperatures to the south and east of height gradient/storm track.
Overall, lower than usual confidence in this portion of the long-
term forecast.
It`s a pattern that tends to favor mixed p-types to rain scenarios,
but given the colder air to the north, we do have to watch for
periodic intrusions of this colder air southward that could force
more wintry types than rain. Besides the surface temps, the strength
of each system, their timing in a fast WSW flow aloft and the
thermal structure aloft are all pretty low-confidence at this point.
At this point it looks like a progressive/weaker frontal system
Sunday night into Mon with another system around Tue or Wed that
could be more significant. But as mentioned, details/specifics are
highly uncertain and ensemble trends will need to be monitored.
Have indicated temps still on the above-average side but these too
will also need to be more carefully monitored/adjusted.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
00z TAF Update:
Tonight: High confidence in trends but moderate on the exact
timing.
Conditions deteriorate to MVFR-IFR thru midnight, with IFR/LIFR
into overnight. Steady light to perhaps instances of moderate
snow in the interior should transition to rain by 04z-05z.
Locally heavy rain likely for BOS, PVD and SE MA, Cape Cod and
Islands after 06z. SE winds increase markedly for PVD, BOS SE to
Cape Cod/ACK with gusts 30-45kt. N/W of I-95, E/SE winds around
10- 13 kt gusts to 25 kt. LLWS for RI and eastern MA 06z-09z.
Thursday...Moderate confidence.
IFR/MVFR cigs with light rain, improving to VFR between 16z and 20z.
West winds 15 to 20 kts and gust to 30 kts.
Thursday night...high confidence.
VFR, dry weather but strong west winds 15-25 kt, gusting up to
35 kt during the evening, slowly diminishing overnight.
KBOS Terminal...High confidence. Light rain (briefly mix with
wet snowflakes, nil additional accum) thru late evening to
become steady moderate to heavy rain overnight. MVFR to
deteriorate to IFR.
KBDL Terminal...High confidence. Rain mixed with wet snow thru
02z then transitions to rain, falling moderate to heavy at times
after 03z.
Outlook /Friday through Monday/...
Friday through Saturday Night: VFR. Breezy.
Sunday: Mainly VFR, with local MVFR possible. Breezy. Slight
chance RA.
Sunday Night: Mainly VFR, with local IFR possible. Breezy.
Slight chance RA.
Monday: Mainly VFR, with local IFR possible. Slight chance RA,
slight chance SN.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
430 PM update...
Tonight through Thursday night...High confidence.
* Gale Warnings remain posted
Tonight...
Gale center tracks southwest to northeast into New England. SE gales
likely. Snow quickly changes rain, lowering vsby.
Thursday...
Gale center near Boston at 12z races northeast into the maritimes.
South gales shifting to WSW gales in the afternoon. Morning rain
moves offshore with improving vsbys.
Thu night...
Gale center moves into southeast Quebec with weak high pressure
approaching New England from the west. Thus, diminishing winds. Dry
weather and good vsby.
Outlook /Friday through Monday/...
Friday: Winds less than 25 kt. Local rough seas.
Friday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.
Saturday: Moderate risk for Small Craft Advisory winds with
local gusts up to 30 kt. Seas up to 5 ft.
Saturday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft.
Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft.
Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft. Slight
chance of rain.
Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain.
&&
.TIDES/COASTAL FLOODING...
430 pm update...
* Coastal Flood Advisory from 8 PM Wednesday to 3 AM EST
Thursday.
SSE gales tonight. High tide along the south coast occurs around 11
pm. However, strongest wind, storm surge and pressure falls occurs
after high tide, closer to 1-4 am. This will limit coastal flooding
to only minor inundation. Nonetheless, coastal flood advisory
remains posted.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Winter Weather Advisory until 1 AM EST Thursday for MAZ002>006-
008-009-012-026.
Flood Watch through Thursday morning for MAZ013>021.
Wind Advisory until 9 AM EST Thursday for MAZ017>024.
Coastal Flood Advisory until 3 AM EST Thursday for MAZ020-021.
RI...Flood Watch through Thursday morning for RIZ001>007.
Wind Advisory until 9 AM EST Thursday for RIZ002-004>008.
Coastal Flood Advisory until 3 AM EST Thursday for RIZ002-
004>007.
MARINE...Gale Warning until 7 AM EST Thursday for ANZ230-236.
Gale Warning until 1 AM EST Friday for ANZ231>235-237-250-251-
254>256.
&&
$$
SYNOPSIS...Nocera/Loconto
NEAR TERM...Nocera/Loconto/Gaucher
SHORT TERM...Nocera
LONG TERM...Loconto
AVIATION...Nocera/Loconto
MARINE...Nocera/Loconto
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service State College PA
1038 PM EST Wed Jan 25 2023
.SYNOPSIS...
Gusty winds and snow showers/flurries will linger across the
Northwest Alleghenies and Laurel Highlands through late this
week with additional minor accumulations likely. Temperatures
will trend gradually milder over the weekend with mixed
precipitation possible on Sunday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
The advisory has been extended until 10 PM for Potter and Tioga
Counties, where mesonet obs show pockets of subfreezing air and
road temps. Precip has largely come to an end, but there are
some isolated rain showers and patchy drizzle that could result
in an additional glaze of ice. Elsewhere, temps have warmed
above freezing and the winter weather threat has ended for this
evening.
A band of moderate rain is located ahead of an occluded front
over western PA. It will likely move into the Laurel highlands
by around 8-9 PM, weakening as it moves east into more stable
air.
Winds will increase overnight with peak gusts expected over the
Laurels in the 35-45 mph range. Snow showers and perhaps some
pockets of -fzdz should develop downwind of Lake Erie and over
the Laurel Highlands into early Thursday morning.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
A tight pressure gradient behind the exiting low should produce
gusty northwest winds across the region Thursday. Bufkit
soundings indicate gusts of 35-45mph are most likely.
Light lake effect and upslope snow will remain possible into
Thu morning with upslope westerly flow. As we head into Thursday
afternoon, short range guidance suggests an uptick in snow
shower coverage and intensity across western and central PA,
as low level instability increases and a shortwave trough moves
overhead. The latest NAM shows a large area of Snow Squall
Parameter > 2 over west-central PA by 4 PM, which intensifies
through Thursday evening. Hires NAM and HRRR both show several
west-east oriented bands of moderate to potentially heavy snow
developing across western and central PA during this period.
These snow bands could bring pockets of a few inches of snow
across the Laurels, as well as brief periods of very low
visibility and hazardous travel Thu afternoon and evening. High
temps on Thu will range from the upper 20s in the north to the
low 40s in southeastern zones.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Periods of lake enhanced/orographic snow showers will continue
over the Alleghenies into Friday morning with additional accums
especially in the higher elevations. A relatively cooler end to
the week with maxT near to below climo Friday afternoon.
A broad large scale upper trough will occur across the Central
and Eastern CONUS through Friday night will relax and become
more zonal over the weekend with daytime temps starting out
around normal on Friday and climbing to about 5 deg F above
normal for Sat and Sunday. Cloud cover and breezy conditions at
night will promote overnight lows of 5 to 10F above late Jan
normal values.
A fast moving and moisture challenged flat shortwave will
expand the snow showers across the western Mtns and bring at
least flurries to the Central Ridge and Valley Region of the
state Fri night and Sat morning.
A slightly better organized sfc and upper level trough
(supported by a coupled jet circulation, but with limited deep
layer moisture) will impact much of the state Sunday afternoon
and night, with mixed precip across the south and probably a
light 1-2 inches of snowfall across much of the northern and
western mountains...mainly after dark Sunday.
The large scale pattern across much of the CONUS favors a split
flow next week, where colder air at low levels nosing down from
the north and the eventual location of the thermally
direct/right entrance region of a strong 170 KT upper let could
culminate in a midweek winter storm with snow and mixed precip
spreading NE across the state. EC and GFS model suites are in
fairly good agreement on this systems`s track and timing, though
the EC is slightly warmer and further NW with the track of the
sfc low and 850 mb zero C line.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
Some updates done this evening. Pressure gradient tight across
the coastal areas and also west of the mountains, but not over
central PA now. Thus much of the area has light winds now.
Band of showers still over western sections of central PA as of
late evening. I had a TEMPO group in at LNS for thunder, the
chance of thunder now shifting out of that area.
Earlier discussion below.
A deep low over Ohio late this afternoon will lift northeast
and down the St. Lawrence river valley on Thursday.
Low clouds and fog this evening will give way to gusty winds
late tonight, as a cold front moves across the area. Some
showers ahead of the front early on. Expect temperatures to
hold steady or rise a bit this evening.
Low level winds across much of the area have weaken as of early
evening, as guidance hinted at last night, so will keep LLWS
in the fcst.
The airmass not real cold, snow showers will be mainly across
western areas on Thursday, sites like BFD and JST.
Outlook...
Thu...Gusty NW winds. Light snow showers W Mtns.
Fri...Still a chance of snow showers across the west.
Sat...Improving conds.
Sun...A chance of snow and rain showers, mainly late.
Mon...Still a chance of rain and snow showers.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...DeVoir/Colbert
NEAR TERM...DeVoir/Colbert
SHORT TERM...Lambert/Colbert
LONG TERM...Lambert/Martin
AVIATION...Martin
Area Forecast Discussion
National Weather Service Green Bay WI
958 PM CST Wed Jan 25 2023
Updated aviation portion for 06Z TAF issuance
and new information added to update section
.UPDATE...
Issued at 947 PM CST Wed Jan 25 2023
Had thought that there would be a decrease in the snow in eastern
WI as the main surface low pulled away this evening, but
continued cyclonic flow and the arrival of the northern stream
short-wave has kept the snow going. Have increased pops, QPF and
snowfall amounts (additional 1-2 inches most areas) accordingly.
Also beefed up the lake-effect a bit in northwest Vilas County,
where low-level winds and lake-induced instability will become
more favorable, and synoptic enhancement will occur for several
hours. Wouldn`t be surprising to see another 2 inches there. The
snow is expected to taper off by daybreak northwest, and toward
midday in east central WI.
Have issued a Special Weather Statement to address the travel
concerns overnight, and through the Thursday morning commute
(especially southeast half).
&&
.SHORT TERM...Tonight and Thursday
Issued at 244 PM CST Wed Jan 25 2023
The latest RAP analysis and satellite/radar imagery show low
pressure moving northeast over the Ohio River Valley. The
northern fringes of this storm system are impacting areas from
central to northeast Wisconsin with light snow. Sufficient
instability may be present for minor enhancement of the snow off
Lake Michigan, but any enhancement has been difficult to detect.
Area webcams show little to no accumulations on the roads so far
today, but will keep a mention of slippery spots on bridges and
overpasses. Meanwhile, a northern stream shortwave is slowly
moving east across the northern Mississippi Valley. Light snow
showers have mainly remained west of the region so far today. As
these systems pass across the region, light snow trends and
amounts are the main forecast concerns.
Tonight...The strong cyclone will move across the eastern Great
Lakes. The back edge of the comma head will continue to impact
northeast Wisconsin with light snowfall through the evening and
will increase snow chances. Then the shortwave trough/PV anomaly
will move across the region from late evening through the
overnight hours. Forecast soundings indicate sufficient saturation
for light snow showers for most locations with this feature.
Total snowfall for tonight will remain light and generally at a
half inch or less. With the cloud cover, low temps will remain
above normal and range from the middle teens to middle 20s.
Thursday...Shortwave troughing will exit northeast Wisconsin by
midday or early afternoon. Potential for light snow accumulations
will continue in the morning before deep saturation exits with the
shortwave. Additional accumulations may only amount to a dusting.
Subsidence will arrive behind the wave for the afternoon with
drying occurring the mid-levels. However, the RAP/HRRR forecast
soundings show a sharp inversion developing with moisture trapped
beneath. As a result, trended cloud cover higher. Highs will range
from near 20 in the north to the upper 20s over the Fox Valley and
lakeshore.
.LONG TERM...Thursday Night Through Wednesday
Issued at 244 PM CST Wed Jan 25 2023
A fast moving clipper system will cross into the region early in
the extended, bringing light snow to the region overnight into
Friday morning. Moisture with this system will be fairly sparse,
but a quick inch or less of snow will still be possible for the
region. Wind gusts will reach around 30 mph with the front as
well, so despite the low snow totals, visibility in some areas may
be low for the Friday morning commute. Snow will be fairly short-
lived for the region, with dry conditions returning by Friday
evening.
The next fast moving system will arrive from the south on
Saturday. Overrunning precipitation from the passing southern
stream system will work its way into portions of central to east-
central WI, but most northeast WI will likely only see an increase
in cloud cover. Like the system before it, those that see snow
will only get a quick dusting to around less than an inch. This
total could increase slightly if the system continues the more
northerly trend from the past 24 hours. Highs on Saturday will be
in the single digits across the north and upper teens near the Fox
Valley.
After Saturday, precipitation trends become more uncertain as
colder and drier air settles in over the region. Models do bring a
few hints of precipitation in next week, but timing is unclear.
With the lack of moisture, any passing systems are unlikely to
produce much in the way of snow. Temperature-wise, highs will drop
into the single digits everywhere but the Fox Valley and
lakeshore by Monday. High temps might then rise a few degrees by
the middle of next week but will still be considerably colder than
what we`ve had through much of January.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 947 PM CST Wed Jan 25 2023
Light snow and associated MVFR/IFR conditions will persist
overnight, then gradually taper off from northwest to southeast
through midday Thursday. Expect improving conditions as the upper
trough departs Thursday afternoon, with VFR flight conditions
possible in the mid to late afternoon.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.........Kieckbusch
SHORT TERM.....MPC
LONG TERM......Uhlmann
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Grand Rapids MI
906 PM EST Wed Jan 25 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 906 PM EST Wed Jan 25 2023
We have dropped the advisory for the synoptic storm snowfall which
is currently tapering off and ending. The advisory for Thursday
lake effect snow is unchanged.
Radar trends and obs showing synoptic snow has diminished or ended
across the forecast area as f-gen forcing weakens and with no
additional accumulations expected. Cyclonic flow persists on the
backside of the departing low. Inversion heights will not be an
issue as lake effect bands currently seen developing over Lake
Michigan eventually curl onshore late tonight into Thursday.
&&
.DISCUSSION...(This evening through next Wednesday)
Issued at 345 PM EST Wed Jan 25 2023
--Accumulating Synoptic Snow Ending This Evening--
Sfc low over wrn Ohio is tracking pretty much as expected and
will pass between TOL and CLE before continuing northeast and
phasing in with the potent system to affect New England. Look for
best/accumulating snow to diminish quickly after 00Z this evening
as best omega on the nw side of the low departs. However some
scattered light snow showers or flurries will probably linger much
of the night within weak mid level deformation zone and moist
cyclonic flow on the back side of the low which hangs back over
Michigan.
--North-Northwest Flow Lake Effect Thursday--
Colder air arrives via northerly winds on the back side of the
departing synoptic system with H8 temps near -12C arriving on
Thursday. Deep moisture is shown to remain in place into Thursday
evening and fcst soundings at LDM and LWA have no inversion
present aloft as delta Ts become more favorable for heavier LES.
This set up will yield the potential for a dominant band to
develop down the length of the lake which could become intense as
it wiggles near/along the coast and eventually comes onshore. For
this reason will extend the advisory into Thursday for Allegan
and Van Buren Counties and add in Mason/Oceana Counties as well.
Not all of these counties will be impacted given the typical
localized nature of lake effect bands and accumulations may be
limited to the coast.
It`s possible that additional counties will eventually become
affected by localized heavier lake snows Thursday afternoon and
evening as the low level flow backs. Latest HRRR is even
suggesting the possibility of a meso-low coming onshore around
Holland and continuing toward AZO. Also some idea shown of more
intense bands spreading well eastward along I-94/I-80.
--Front with Southwest Flow Lake Enhancement Friday--
Not much of a break before a nrn stream shortwave drops in from
the northwest and drives a sfc cold front through late in the day
Friday. Lake snows should ramp up again Friday morning in the
southwest flow preceding the front, with accumulations possible
along the lakeshore north of Holland. Then as winds veer with the
frontal passage look for a combo synoptic/lake enhanced event to
impact a large part of the area as snowshowers spread farther
inland. This is probably a 1-2" event for most of the area, but
locally higher amounts (2-5"?) for Holland/GRR northward.
--Another Synoptic Snow Arriving Saturday--
Going into the weekend the mid level baroclinic zone remains
nearby with 100-130 kt H2 jet riding along it. Models are
developing a relatively narrow area of snow Saturday and Saturday
night which moves from Iowa to srn Lwr MI... just north of the sfc
boundary and associated with a stronger jetlet. This may be
another 1-3" (possibly higher) type of event-- and there`s
even another possible synoptic system around Tue-Wed of next
week. The pattern has definitely become more active, as it should
be in late January.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 630 PM EST Wed Jan 25 2023
Conditions will be improving from IFR to MVFR this evening as snow
tapers off and ceilings come up a bit. MVFR conditions will
prevail overnight with some IFR in lake effect snow showers on
Thursday, mostly within 20 miles of Lake Michigan, but winds will
go west during the afternoon and snow showers will move inland
with some areas of IFR making it to AZO and GRR and possibly
further east after 21Z.
Winds will be northwest less than 10 knots tonight and most of
Thursday.
&&
.MARINE...
Issued at 345 PM EST Wed Jan 25 2023
We have a small craft advisory in effect for the northerly flow
which increases tonight on the back side of our departing sfc low.
A gale watch has been added for the cold front which comes
through on Friday. The southwest winds ahead of this feature may
reach gale force.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory from 4 AM to 4 PM EST Thursday for
MIZ037-043.
Winter Weather Advisory until 4 AM EST Friday for MIZ064-071.
LM...Small Craft Advisory until 10 AM EST Friday for LMZ844>849.
Gale Watch from Friday morning through Friday evening for
LMZ844>849.
&&
$$
UPDATE...Ostuno
DISCUSSION...Meade
AVIATION...Ostuno
MARINE...Meade
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
929 PM EST Wed Jan 25 2023
.SYNOPSIS...
Snow has started to overspread the area from southwest to
northeast as low pressure approaches from the Ohio Valley.
Snowfall rates will ramp up this evening into the first part of
tonight. Overnight warm air aloft and then at the surface
marches northward bringing a wintry mix to rain south of the
mountains and snow to a wintry mix across the north before
precipitation tapers to rain and snow showers Thursday. Mostly
quiet weather is expected Friday into the weekend before a weak
system approaches Sunday bringing mostly snow showers into
Sunday night with rain showers more likely across the far south.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Update...Steady march northward of the reduced CC on radar shows
mixing continues to progress into the forecast area at this
hour. Coastal front is more or less holding steady...but
featuring a sharp 10 degree gradient. It is 36 on Cape
Elizabeth...30 at PWM...and 25 near the Falmouth Spur. That is
dictating ptype along the coast...while the radar CC is showing
where sleet and freezing rain are beginning to mix in. I have
updated ptype as best I could...while reduced snowfall in favor
of mixed precip around the edges of the forecast area. The mtns
and foothills will see moderate to heavy snow thru the overnight
gradually giving way to mixed precip...while to the south it
will be sloppy night and a kitchen sink type forecast.
Previous discussion...Satellite imagery this afternoon shows
that the status- cumulus deck in association with a developing
area of low pressure near the Delmarva is continuing to advance
northeastward across the region. Northeast radar mosaic imagery
shows weak returns also now extending across all of NH along
with portions of southwestern ME. ASOS, webcams, and ground
observations indicate that pockets of light snow are now
reaching the surface with visibility at times being reduced to
less than 2 miles. A continued downward trend in conditions is
expected through the remainder of the day and as such the first
segment of the winter headlines are now in effect. Decided not
to push up the start time for the next tier yet as little to no
impacts are expected across these areas until this evening.
Temperatures across the region are mainly into the upper 20s to
lower 30s but they may drop back a degree or two as we wetbulb.
Tonight a rapidly intensifying area of low pressure to our south
will march northeastward through eastern New England, providing
us with a mixed bag of precipitation types overnight depending
on location. All snow is expected initially and rapidly
deteriorating road conditions are likely as we approach sunset,
especially across the southern two-thirds of the forecast area.
The latest WPC Snowband Probability Tracker (STP) indicates that
enhanced snowfall rates approaching 1"+/hr are possible
beginning at around 7pm across southern NH before spreading into
southwestern ME between 6-9pm. The HRRR also shows this
potential, with some signal for rates to approach 2"/hr. These
will be associated with a ribbon of strong frontogenetical
forcing within the WAA regime along with strong omega within a
fully saturated DGZ.
Eventually the increasing WAA aloft will reduce cloud ice and
drier air will begin to be entrained into the DGZ, which will
reduce snowfall rates across southern areas but moderate to at
times heavy snow will likely continue through early Thursday
morning across the mountains and north. Speaking of WAA, snow
will begin to transition to rain first across southern NH and
coastal ME between 8-10 pm before lifting into central NH and
the coastal plain of ME by or shortly after midnight. During
this transition across areas away from the immediate coast, a
period of mixed wintry precipitation is expected with ice
accretions between one to locally two tenths of an inch
possible. Snowfall across these regions will range from a slushy
1-3 inches along the coast to 3-5 inches a few miles inland and
then 4-8 inches across central NH south of the lakes region as
well as interior western ME south of the foothills. Further to
the north of this, snow will likely linger for a few extra hours
into the overnight and therefore 6-10" are likely with
localized higher amounts likely, especially across the higher
terrain.
Lastly, winds will become gusty overnight and into Friday
morning, especially along the Mid-Coast as the storm makes it`s
closest approach with some gusts up to 45-50 mph. As a result, a
Wind Advisory has been issued for coastal Waldo and Knox
counties.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Rain along the coast and south-central NH and rain or mixed
wintry precipitation across the foothills of ME will end from
west to east on Thursday morning with just some lingering
drizzle or sprinkles likely through the early afternoon. Across
the north and mountains, after a brief break in the
precipitation late morning it will once again start up again
later in the day as the upslope flow kicks in. Lingering impacts
to the Thursday morning commute are expected, especially away
from the coast as there will still be remaining slush on
unplowed walkways and roadways along with pockets of icy spots.
It will otherwise be a mainly cloudy day with temperatures
eventually rebounding into the upper 30s to even lower 40s south
of the mountains.
Mainly dry conditions will then prevail on Thursday night but
we will remain under cyclonic flow with upslope snow showers
continuing across the north and mountains. Otherwise breezy and
cool conditions are expected with overnight lows into the teens.
High pressure then begins to build in on Friday, although a weak
surface cold front may cross early in the day but with very
little sensible weather impacts. Highs will be into the 20s in
the north to the low 30s south.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Broad troughing through the central portion North America will start
the long term period with building heights in the Gulf of Alaska
extending poleward over the upcoming weekend. The axis of this broad
trough will extend westward into the SW CONUS while positive height
anomalies emerge over the East Coast during the early to middle part
of next week. This will set up a relatively active pattern through
the long term period, although systems look to be weak with no real
signs of systems that will bring significant impacts. Temperatures
will trend above normal along the East Coast while much colder air
hangs back over the Plains into the Great Lakes with forecast area
seeing a mix of above to below normal temperatures. A series of
disturbances will track between the broad trough and the building
ridge bringing chances for precipitation, although the timing and
strength of these disturbances remains somewhat unclear. Two of the
more notable disturbances pass through Sunday afternoon into Sunday
night and the other around next Wednesday. This is when PoPs are
highest with snow showers favored for much of the area, although
cannot rule out precipitation falling as rain at times across
southern New Hampshire and coastal Maine.
Friday will be feature partly to mostly sunny skies with breezy west
to northwest winds. Highs will range from the teens north to low 30s
south. A cold front tracking across SE Canada will bring chances for
mountain snow showers Saturday while the south looks to be mostly
dry with partly sunny skies. Highs on Saturday will range from the
low 30s north to low 40s across far southeast New Hampshire.
A weak area of low pressure will cross New England Sunday afternoon
through Sunday night. QPF amounts look to be on the light side
topping out around a third of an inch. Thermal profiles support
mostly snow across the north two thirds of the forecast area with
rain favored across southern New Hampshire into portions of York and
Cumberland County. Where precipitation stays all snow a few inches
will be possible, although amounts look to stay below Advisory
thresholds. PoPs drop below slight chances on Monday for much of the
area with temperatures dropping closer to normal in the wake of the
weak low pressure system. From Tuesday through the end of the
forecast period have stuck close to the NBM for PoPs as run to run
and model to model continuity drops off. This brings slight chance
to chance PoPs Tuesday with higher PoPs Wednesday that climb into
the 40 to 50 percent range. Thermal profiles on Wednesday will
support mostly snow across the northern two thirds of the area with
SE New Hampshire and coastal SW Maine warming enough that
precipitation may fall as a mix of rain and snow.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Short Term...SN will continue to overspread the region from SW
to NE this evening with SN transitioning to RA from S-N and
along coastal TAF sites later this evening through the first
half of tonight with KMHT, KPSM, KPWM, and KRKD transitioning
first. During this transition, a period of FZRA/PL is possible,
although this should be short lived. Otherwise IFR/LIFR
restrictions will prevail through Thursday morning along with
LLWS of WS020/160-19035KT until about 12Z. Conditions will then
begin to improve later Thursday morning from W-E, although MVFR
CIGS will likely linger through much of the day.
Long Term...Mainly VFR Friday into the first part of Sunday. Weak
low pressure crosses Sunday afternoon and night bringing light snow
across much of the area with MHT, CON, and PSM likely seeing rain
mixing with snow. Lowering Cigs and -SN or -SNRA will likely bring
some flight restriction Sunday evening into Sunday night with
improving conditions Monday.
&&
.MARINE...
Short Term...Low pressure crosses across the waters late tonight
through Thursday morning, bringing gale force winds across the
bays and southern waters with storm force winds in the eastern
outer waters and seas of 6-12 ft. Widespread rain is also
likely. Winds turn offshore later Thursday behind the departing
low, likely remaining at gale force through Friday morning
before weakening.
Long Term...West to Northwest winds relax Friday although gusts may
still exceed SCA thresholds Friday morning and seas remaining above
SCA thresholds into Friday night. SW flow increases Saturday gusting
to SCA thresholds with a few gusts to Gale Force along the outer
waters. Winds and seas drop below SCA thresholds Sunday into
Monday, although a few gusts to 25 kts will be possible Sunday
afternoon.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Warning until 3 PM EST Thursday for MEZ007>009-
012>014-019>022-033.
Winter Storm Warning until 10 AM EST Thursday for MEZ018.
Winter Weather Advisory until 7 AM EST Thursday for MEZ023>028.
Wind Advisory from 3 AM to 10 AM EST Thursday for MEZ027-028.
NH...Winter Storm Warning until 3 PM EST Thursday for NHZ001>006.
Winter Storm Warning until 10 AM EST Thursday for NHZ007>010.
Winter Weather Advisory until 7 AM EST Thursday for NHZ011>013-
015.
MARINE...Storm Warning from 1 AM to 10 AM EST Thursday for ANZ150.
Gale Warning until 10 AM EST Thursday for ANZ151>154.
&&
$$
NEAR TERM...Legro
Area Forecast Discussion
National Weather Service Hanford CA
323 PM PST Wed Jan 25 2023
.UPDATE...Updated air quality issues section.
&&
.SYNOPSIS...Dry and cool conditions will prevail through
Saturday. A low pressure system will drop southward through
California on Sunday and Monday bringing a chance of rain and
mountain snow to the area. Drier conditions will return by the
middle of next week.
&&
.DISCUSSION...Upper ridge situated off the western CONUS coast
maintaining clear skies and dry conditions across our area today.
Some dense fog was observed across portion of the central San
Joaquin Valley this morning along a strip from Selma to Hanford
to Corcoran which dissipated by late morning. HRRR indicating
conditions will be more favorable for widespread dense fog across
the valley tonight as a result of clear skies, light winds in the
San Joaquin Valley and less mixing than what took place this
morning. Have therefore issued a Dense Fog Advisory for much of
the San Joaquin Valley from 200 am PST until 1000 am PST Thursday.
Temperatures are expected to continue to nudge upward on
Thursday and Friday. Latest NBM probabilistic guidance is
indicating that most of the valley has between a 15 and 30 percent
chance of subfreezing temperatures on Thursday morning and between
a 5 and 20 percent chance of subfreezing temperatures on Friday
morning.
Ensembles are in good agreement with retrograding the ridge
further westward off the coast over the weekend which will allow
for a cold upper low to drop southward over CA on Sunday and
Monday. While this system is moisture deficient, it will provide
for enough instability for chances of precipitation across our
area on Sunday and Monday. This system is also progged to be cold
with snow levels lowering to 2500 to 3000 feet on Monday so the
main concern with it will be the possibility for snow on the
major passes in Kern County on Monday. Latest NBM probabilistic
guidance is indicating between a 25 and 35 percent chance for
measurable snow in the Tehachapi Mountains on Monday.
This system is progged to move out of our area by Monday night
with ensemble consensus indicating a cold and dry airmass
prevailing over our area behind it during the middle portion of
next week. The concern will then become the potential for sub-
freezing temperatures in the San Joaquin Valley next Tuesday and
Wednesday mornings.
&&
.AVIATION...In the San Joaquin Valley, local MVFR in mist/haze
thru 06Z then becoming mainly IFR in mist by 10Z Thu with areas
of LIFR in fog through 18Z Thu the mainly MVFR with areas of IFR
in mist/haze after 18Z Thu. Otherwise, VFR conditions will prevail
across the central CA interior for the next 24 hours.
&&
.AIR QUALITY ISSUES...On Thursday January 26 2023, Unhealthy
for Sensitive Groups in Fresno and Kern Counties. Fireplace/Wood
Stove Burning Status is: No Burning For All in Fresno and Kern
Counties. No Burning Unless Registered in Kings, Madera, Merced,
and Tulare Counties. Burning Discouraged in Kern (Greater Frazier
Park Area) and Sequoia National Park and Forest.
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
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
and/or to provide feedback.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from 2 AM to 10 AM PST Thursday for
CAZ301>303-305>307-309>312-315.
&&
$$
public/avivation/fire wx...DS
pio/idss...JDB
weather.gov/hanford
Area Forecast Discussion
National Weather Service Indianapolis IN
1042 PM EST Wed Jan 25 2023
.Forecast Update...
Issued at 1042 PM EST Wed Jan 25 2023
Snow showers are expected to continue over the next 24 hours across
Central Indiana as cyclonic flow remains in place under a broad
upper trough with multiple vort maxes rotating through the region.
Current Nighttime Microphysics satellite imagery depicts the
incoming wave well across Iowa and Southern Minnesota with surface
observations reporting snow and reduced visibilities. ACARS
soundings from up there show deep saturation from the surface up to
around 700mb, including the dendritic growth zone, indicating
sufficient moisture for snow showers. Even the IND ACARS sounding
still show deep saturation through the DGZ this evening, so P-type
is no concern through tomorrow as RAP forecast soundings and cross
sections keep deep saturation through the region. Forcing comes in
the way of upper level vort maxes swinging through the region and
areas of low level frontogenetical forcing allowing for scattered to
numerous snow shower development. Best chance for snow showers
across the region appears to be earlier in the day from the early
morning hours through early afternoon, tapering off during the
evening. Forcing and saturation within the DGZ wane later in the
evening tomorrow indicating snow showers may taper off to light
flurries and areas of drizzle before precipitation fully shuts off.
So would not be surprised to see slick spots tomorrow night as
temperatures plummet into the lower 20s.
As far as accumulations, snow amounts will very across short
distances due to the showery nature of the precipitation. Heaviest
snow showers will likely be along and north of I-70 where upwards of
an inch to possibly 2 inches could fall in some spots. Lighter
amounts expected across the southern half of Indiana. Because these
are showers, some areas could be missed entirely with just flurries
and cloudy skies tomorrow... hence the wording "scattered" snow
showers.
Low and mid level lapse rates steepen somewhat as cold air advection
continues to filter in aloft tomorrow. This combined with winds
around 20-30 kts just above the surface may lead to a few stronger
gusts to 25-30 kts mixing down to the surface, especially in
stronger snow showers. This could reduce visibility at times.
&&
.Short Term...(This evening through Thursday)
Issued at 309 PM EST Wed Jan 25 2023
* Snow rapidly tapering off across north central Indiana.
* Additional flurries possible this evening, with snow showers
possible later tonight into Thursday. Light accumulations possible
in some areas.
As the primary low pressure system that brought wet snowfall to the
area today rapidly departs to the northeast, focus for the short
term will shift to potential for additional light snow showers at
times, primarily late tonight through Thursday.
With the snow rapidly coming to an end, and significant melting
leading to primarily wet roads, have cancelled the remaining
headlines across the northern portion of the area.
Some modest midlevel drying noted on forecast soundings is causing
some changeover from light snow to drizzle on the southern end of
the departing snow shield. Temperatures should remain above freezing
across the majority of the area into this evening and limit any
impact due to this.
The initial weakening shortwave accompanying today`s snowfall will
be followed by weak subsidence during the evening hours, which will
very likely prevent any additional measurable precipitation during
the early part of the night, with flurries or drizzle remaining
possible. Late tonight into Thursday, additional subtle upper level
disturbances in the broader cyclonic flow will impinge upon the
region and produce potential for additional snow showers.
Additionally, low level flow configuration may allow some lake
enhancement to this activity across our north/northeastern forecast
area, and will carry the highest pops in these areas.
Very light QPF is expected, likely around 0.05" or less in most
areas, but with the onset of cold advection, snow ratios will
increase well above the 3-5 to 1 observed today to near
climatological average of around 11 or 12 to 1. This will result in
amounts of around a half inch with isolated 1 inch amounts. This
will likely not be uniform as activity will be a bit more showery in
nature.
Despite the onset of cold advection, widespread cloud cover will
significantly limit diurnal range through Thursday, with lows
tonight likely remaining no cooler than the upper 20s to low 30s and
highs tomorrow barely budging into the low 30s.
&&
.Long Term...(Thursday night through Wednesday)
Issued at 309 PM EST Wed Jan 25 2023
The long term period will see multiple chances for precipitation.
For Thursday night through Sunday, there is not a lot of
variation between models which show a positively tilted trough
stretching from north central Canada towards the Rockies. This
trough will persist into the middle of next week as well with some
forward progression, but there is less agreement amongst models
for the end of the period. Multiple short waves will ride along
the leading edge of the trough which is where the numerous precip
chances will arrive from.
The first shortwave in the long term will come Friday afternoon as
the associated surface low tracks just north of the Great Lakes.
Best chances for precipitation will be mainly across the northern
half of the forecast area and will likely be light. Temperatures
will be flirting with the freezing line as afternoon highs are
expected to range from the mid 30s to near 40 so expect a mix of
rain and snow for the ptype. Up to half an inch of snow accumulation
would be possible but could see it not sticking around for very long
given the temperatures. At the low to mid levels, a broad jet will
set up aloft which should mix down some breezy winds to the surface.
Could see wind gusts up to around 35 mph Friday.
After a shot of drier air, another short wave, with a better
moisture content than the first wave, will bring PoPs and light
precipitation from late in the day Saturday through the day Sunday.
Again a mixture of precip type will be likely with this system but
in this case will be due to warmer temperatures of upper 30s to low
40s to start out with late Saturday followed by colder air slowly
pushing southeast through the night and into the day Sunday. The
transition to snow could begin in the far NW as early as prior to
daybreak. Will need to watch for freezing precipitation that could
mix in during the day Sunday, but confidence is not high enough for
a day 5 forecast to include in the grids at this time.
A surface high will then move through Monday providing another break
in PoPs for the start of the work week but we could see another
chance of precipitation for the end of the period. There is quite a
bit of variability in the solutions so many details are yet to be
seen but could again see a mix of precip type with this late period
system as well.
Temperatures through the period will start out slightly above normal
for the first half of the period and then become slightly below
normal for the latter half.
&&
.Aviation...(00Z TAF Issuance)
Issued at 635 PM EST Wed Jan 25 2023
Impacts:
* IFR ceilings likely through most of the period
* Scattered light snow showers will develop late tonight and
continue on Thursday
Discussion:
Last of the light returns on the back side of this system are moving
out as we speak early this evening. Generally...this has fallen as
pockets of drizzle over the last few hours. Expect dry weather for
much of the evening into the early overnight as weak ridging aloft
shifts across the area. With deep moisture lingering throughout the
low levels...IFR ceilings will persist through the evening with
W/NW winds at 10-15kt.
As an upper level disturbance pivots across the region Thursday
morning...expect scattered snow showers to expand during the predawn
hours and continue for much of the day Thursday. Visibilities will
be variable as snow showers pass the terminals but IFR stratus will
persist all day before lifting to MVFR late day. Winds will back
through the day to W/SW and may sporadically gust at times to near
20kts.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...CM
Short Term...Nield
Long Term...KH
Aviation...Ryan
Area Forecast Discussion
National Weather Service Louisville KY
946 PM EST Wed Jan 25 2023
.Forecast Update...
Issued at 945 PM EST Wed Jan 25 2023
Temperatures are now running in the mid 30s across most of central
KY and southern IN this evening. Sfc dewpoints remain in the mid 30s
as well, and scattered light precipitation has mainly been liquid up
to this point. Temperatures will slowly fall tonight, reaching the
lower 30s in most places by the early morning hours of Thursday.
South-central KY east of 65, especially the Lake Cumberland region,
should only bottom out in the mid 30s.
By the early morning hours, precip should be pretty spotty but with
snow as the primary p-type. Steep lapse rates mean that the cloud
layer is below freezing, with the top of the cloud layer certainly
cold enough for ice nucleation. After 09z Thu, the potential for
impactful snow showers increases. Low-level stability decreases
while low-level moisture remains sufficient for scattered showers.
Will even have some modest low-level CAPE (~50 J/kg). Sfc temps will
be marginal or slightly below freezing. Recent runs of the HRRR have
suggested perhaps a slight uptick in precip coverage around or
shortly after sunrise. But in terms of coverage, think that it will
be "scattered" at worst.
Sfc temperatures are likely to remain fairly steady through the
morning hours, with road pavement temps likely remaining above
freezing outside of shower activity. However, some of the snow
showers could be more intense and produce brief reductions to
visibility. Scattered snow showers may also quickly coat roads in
some areas, especially where snow showers can linger or train.
Though localized in nature, minor travel impacts are certainly
possible. So have issued a Special Weather Statement for all of
central KY and southern IN to highlight the possible wintry impacts
on Thursday. Again, everyone will not see accumulation. Everyone
will not even see snow. But some of the snow showers could be
heavy/intense enough to cause issues.
Issued at 655 PM EST Wed Jan 25 2023
The Wind Advisory has been canceled for the rest of central KY.
Winds are now solidly below criteria, but gusts of 20-30 mph will
remain possible this evening.
&&
.Short Term...(This evening through Thursday)
Issued at 310 PM EST Wed Jan 25 2023
...Potentially Impactful Snow Showers Possible Thursday...
Current surface analysis indicates that the low pressure system is
lifting off to our NE through east-central OH, with westerly winds
on the backside of the low beginning to advect cooler air into the
region. Temperatures along and west of I-65 have started to drop
into the upper 30s to lower 40s while points across east-central KY
remain in the mid to upper 40s. Low stratocumulus clouds continue to
blanket much of the area; however, have seen some breaks in the
clouds east of I-65, which also correlates with where we have seen
our highest wind gusts. Within the Wind Advisory area, gusts of 40
to 45 mph have been common along with a couple of gusts above 50 mph
at KLEX, KFFT, and the Cynthiana Mesonet. Gusty SWly winds will
continue for the next few hours for points east of I-65 before winds
gradually "weaken" into this evening as the surface low lifts into
the Lower Great Lakes region. In the wake of the surface low,
westerly winds will prevail through Thursday with sustained wind
speeds in the 10 to 15 mph range along with occasional gusts of 20
to 25 mph.
Radar imagery shows scattered rainfall is beginning to push into the
Bluegrass region, with mostly dry weather observed across the rest
of the area. As we remain beneath cyclonic flow aloft, model
guidance indicates that isolated to scattered rain and snow showers
will start up again after 26/00Z and continue into Thursday.
Scattered precip tonight will likely begin as rain as temps will
still be making their way towards the freezing mark, with a
transition to mostly snow by early Thursday morning. Model soundings
indicate that as we progress through the morning hours, lapse rates
in the lowest kilometer will steepen, with saturation extending into
the -10 to -15 C range. Additionally, anticipate some weak
instability with SBCAPE of 25 to 75 J/kg. As a result, cannot rule
out some scattered intense snow showers or snow bands setting up
Thursday. Within these bands, higher precip rates may result in
sudden reductions in visibility and quick accumulations of 1 to 2
inches will be possible. Confidence remains low on any specific
locations or timing though, so have kept in Slight Chance to Chance
PoPs across the entire area.
.Long Term...(Thursday night through Wednesday)
Issued at 305 PM EST Wed Jan 25 2023
---------------------------------------------------------------------
Key Messages:
- Gusty winds on Friday
- Break from precipitation on Saturday
- Cold front passage on Sunday with rain/snow showers along and ahead
---------------------------------------------------------------------
Thursday night - Friday night...
As the previous low system continues to track farther to the
northeast, the snow showers will also exit the region.
A shortwave trough over southern Canada will continue to track
eastward over Friday. The Ohio Valley will be clipped by this
system, remaining mostly dry. Moisture is limited, so any light rain
showers should be limited to southern Indiana and far northern
Kentucky. Conditions in the northern portion of the CWA will remain
cloudy as this system sweeps through. Forecast soundings over the
area show an dry adiabatic profile up to about 850mb; therefore,
gusty winds of 25-35mph will steadily increase throughout the
afternoon on Friday.
Saturday...
After the shortwave trough moves off to the east, primarily zonal
flow with small, brief ridging will begin to set in. Low
temperatures Saturday morning will be in the low 30s, with
decreasing cloud cover through the day, and high temperatures in the
mid 40s.
Saturday night - Wednesday night...
The low pressure system that clipped the region on Friday will
deepen to the northeast over Canada, and the cold front will begin
to move south into the region on Sunday morning. Along and ahead of
this front, rain showers will sweep through the area on Sunday that
could transition into light snow showers early Monday morning.
Beyond Monday, a low pressure system will begin to form over Texas
and track over the Tennessee/Ohio Valleys. Models are unclear on
timing and position of the low center, but something to monitor over
the next few runs.
&&
.Aviation...(00Z TAF Issuance)
Issued at 654 PM EST Wed Jan 25 2023
Impacts...
* MVFR to IFR conditions to continue through the TAF period
* Scattered snow showers possible beginning late tonight into early
Thursday morning
* Breezy with westerly gusts up to 20-25 kt
Discussion...
Pockets of light rain are spreading east across central KY and
southern IN this evening with wrap-around moisture remaining rather
deep. Sfc temps remain solidly in the mid/upper 30s, so not
expecting significant wintry impacts 00-06z this evening. Overnight
and certainly by early Thursday morning, should see snow win out as
the main p-type instead of rain. Isolated to scattered snow showers
will be possible throughout Thursday and could bring a quick dusting
(again, localized in nature).
IFR to MVFR stratus will linger throughout this TAF period with some
modest improvement in ceiling height Thursday afternoon. Westerly
winds will remain breezy throughout the period with gusts to around
20 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update...EBW
Short Term...JML
Long Term...SRM
Aviation...EBW
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
812 PM CST Wed Jan 25 2023
.UPDATE...
Issued at 812 PM CST Wed Jan 25 2023
Made some minor adjustments to going forecast, mainly to increase
pops for light snow to likely across the entire forecast area
tonight. Also bumped QPF slightly across our west/southwest counties
where light snow looks to be a little more widespread this evening
than previously indicated, though snow amounts remain similar with
relatively low snow to liquid ratios.
Early evening surface analysis depicts 997 mb low along the Ontario
shore of Lake Erie, with a surface trough trailing back into the
upper Mississippi Valley. A second weaker low has become indistinct
within the western portion of this trough over the upper Mississippi
Valley. While this second surface low was not obvious in the
pressure/wind field, a fairly sharp low level thermal gradient was
evident along the Mississippi River vicinity as noted by surface
temps in the lower 30s across WI/IL and the teens/20s across central
and eastern IA (and single digits farther upstream). Regional radar
mosaic has shown a blossoming of returns in the vicinity of the
Mississippi, likely associated with low-level frontogenetic forcing
along the eastern periphery of the push of arctic air. RAP depicts
this best around the 925 mb level from southeast MN into eastern IA
and far western IL, and suggests this increase in f-gen forced light
snow will continue to spread into our west and southwest counties
over the next several hours. Light snow persists in cyclonic flow
across much of the remainder of the forecast area as well, along
with some lake-induced convective snow showers becoming evident
across far southern Lake Michigan and the Lake/Porter county shores.
Expectation is that light snow will continue across the area
overnight as the mid-level wave over the upper Valley propagates
southeast, with the potential for some additional minor
accumulations. Greatest overnight amounts (perhaps an inch or a
little more in spots) will likely be across those west/southwest
counties where the aforementioned low-level f-gen forcing will be
focused, as well as across Lake and especially Porter counties where
lake effect snow showers eventually shift east. Elsewhere accums
should remain generally less than an inch overnight.
Light snow will likely persist into Thursday morning as the mid-
level wave transits the area. Forecast soundings indicate some mid-
level drying behind this wave by afternoon, though persistent cold
advection and steepening low level lapse rates will likely allow for
at least scattered snow showers in the afternoon as yet another mid-
level short wave trough drops across the area. No changes made
beyond tonight at this point however, as going forecast appears to
have these trends handled appropriately.
Ratzer
&&
.SHORT TERM...
Issued at 315 PM CST Wed Jan 25 2023
Through Thursday night...
We have ended our winter weather advisory for all but Lake and
Porter counties in IN with the update this afternoon. With
temperatures hovering around freezing, impacts from the lingering
light snow late this afternoon will be minimal at best.
The main forecast messages during the short term forecast are:
* Periodic light snow showers expected tonight, with any more
vigorous showers tied to lake effect over portions of Lake and
Porter counties in IN this evening.
* Snow showers continue on Thursday, with potentially more
vigorous snow showers possible across parts of northeastern IL
and far northwestern IN in the afternoon.
Snowfall rates continue to abate across the area early this
afternoon as the main storm system responsible for this morning`s
snowfall continues to shift northeastward into northwestern OH.
While light snow will continue to fall across the area into this
evening, surface temperatures will continue to hover around
freezing, thus limiting additional accumulations and travel
impacts. For this reason, we have opted to end the winter weather
advisory early for all but Lake and Porter counties in IN, where
the threat of additional accumulation from lake effect snow
showers continues this evening.
Northerly winds, developing along the western periphery of the
exiting area of low pressure, are expected to set up a favorable
fetch on Lake Michigan to support lake effect snow showers into
parts of Lake and Porter counties in IN tonight. While the
thermodynamic setup over the lake is not expected to be all that
impressive, lake induced inversion heights nearing 7,000 ft should
be sufficient to support some accumulating snow showers tonight
along the southern edge of the lake where the better lake induced
convergence axis sets up. HIRES guidance continues to focus this
convergence axis into parts of northeastern Lake IN and northern
Porter county this evening as the lower level flow backs
northwesterly. While this suggests this area will be favored for a
period of accumulating lake effect snow showers this evening, it
appears unlikely that this will be a significant event with a
continuous dominant lake effect band as directional shear in the
unstable layer looks to become somewhat unfavorable through the
evening. Nevertheless, I cannot rule out some localized amounts of
an inch or two this evening across northern parts of Porter
county before the main focus shifts eastward into LaPorte.
Outside of the lake effect, additional periods of snow showers
are expected across the area late tonight and especially on
Thursday as a couple of smaller scale mid-level impulses track
southeastward across the area. Minor additional accumulations are
likely Thursday morning as the first of two waves shifts across
the area. A period of potentially more robust snow showers also
appears plausible across parts of northeastern IL and far
northwestern IN Thursday afternoon as the second impulse
approaches. Lower level lapse rates will steepen in the afternoon
ahead of this second disturbance as a surface frontal trough
shifts southward into northeastern IL. This should foster more
robust snow showers for a period in the afternoon across parts of
the Chicago metro, potentially leading to additional snow
accumulations and reduced visibilities. Travel impacts from these
snow showers is still somewhat unclear, as surface temperatures
hovering close to freezing may act to limit accumulations on
treated roads.
KJB
&&
.LONG TERM...
Issued at 315 PM CST Wed Jan 25 2023
Key Messages
* Snow returns on Friday with another quick inch of snow possible
along with gusty winds to 30 mph resulting in reduced visibility.
* Another round of accumulating snow expected Saturday (potentially
significant), best chances along/north of I-80, with mix of
rain/snow south of there.
* Temperatures turning colder heading into February with highs in
the teens-20s and lows in the single digits-teens next week.
Expect increased ice development on area rivers.
An active weather pattern remains in place through the extended
forecast period bringing multiple chances for wintry precipitation,
the first of which will arrive Friday morning as a quick moving
shortwave/clipper-system moves through the area. This will bring
the potential for snow during the morning and afternoon. Winds
ahead of this wave will become quite gusty out of the southwest
which will help warm temperatures at the surface. Can`t rule out a
bit of a rain/snow mix in our far south, but think the
predominant precipitation type will be snow - though we may lose
some of the cloud ice on the back side of the system which could
result in some poor quality snowflakes or drizzle. Total snow
amounts currently look to remain below 1 inch though locally
higher amounts are possible. Temperatures will be increasing
through the afternoon into the mid 30s which should aid in melting
some of what falls earlier in the day.
Friday evening and overnight looks precip free as we briefly reside
between weather systems. Winds will also turn northwesterly, helping
advect colder air back into the area. Expect temperatures to dip
back into the teens and lower 20s, especially if we are able to
briefly clear out clouds as well.
Another round of accumulating snow is appearing likely again on
Saturday as an east-to-west axis of mid-level frontogenesis orients
itself over northern Illinois by Saturday morning. There has been a
fair amount of model consistency in the placement of this feature
and associated snowfall. Will note it is still a few days out so
there is time for things to change as we begin to see how higher-
res guidance handles the system. Half of the event is just beyond
our current snowfall and QPF "official" forecast range, though
significant amounts (>=6 inches) cannot be ruled out for areas
along/north of Interstate-88. South of there we begin to see the
potential for a mix of rain and snow which could reduce snowfall
totals. Stay tuned!
Aside from the snow the other focus in the extended is the return of
winter-like temperatures with highs struggling to reach the 20s
and lows in the single digits and teens. After such a warm start
to the year it will be time to break back out the heavier winter
coats and gloves! Along with the subfreezing temperatures will
come the potential for increasing ice along area rivers.
Petr
&&
.AVIATION...
For the 00Z TAFs...
540 PM...Forecast concerns include...
Light snow this evening and again Thursday morning.
Chance of snow showers Thursday afternoon.
Ifr cigs through Thursday morning, mvfr cigs Thursday afternoon.
Light snow will continue for a few more hours this evening,
reducing visibilities into the 2sm range. This light snow will
slowly diminish as it shifts east by mid evening with only
flurries expected into the early overnight hours. Another period
of light snow is expected to spread across northern IL and the
terminals in the predawn hours and continue through mid morning on
Thursday. Visibilities are likely to be in the 2sm range as well
during this time, possibly lower at times. After this light snow
ends, there will be a continued chance for snow showers Thursday
afternoon. While some of these snow showers may also lower vis
into the 1sm range, confidence is low regarding coverage, which
may remain isolated. Prob mention for this time period seems
reasonable from this distance.
Cigs are quite variable early this evening and are expected to
settle into low mvfr and then lower to prevailing ifr later this
evening and remain ifr through late Thursday morning. There may be
lifr cigs at times with any heavier snow, especially Thursday
morning. Cigs are expected to lift to low mvfr by early Thursday
afternoon.
Winds are expected to remain northwest through the period, perhaps
more north/northwest this evening and then more westerly by later
Thursday afternoon. Speeds generally around 10kts tonight. Winds
may increase by midday Thursday, with gusts into the 20kt range by
early afternoon though confidence for wind speeds/gusts on
Thursday is low. cms
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...Winter Weather Advisory...INZ001-INZ002 until midnight Thursday.
LM...Small Craft Advisory...Winthrop Harbor to Gary IN until 3 PM
Thursday.
Small Craft Advisory...Gary to Michigan City IN until 10 PM
Thursday.
&&
$$
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Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
809 PM CST Wed Jan 25 2023
.UPDATE...
Issued at 801 PM CST Wed Jan 25 2023
Light snow and flurries continue to push through the region this
evening associated with a mid-level shortwave and surface cold
front sliding southeast through the mid-Mississippi Valley. The
column is saturated from the surface through around 850 mb, and
lift within this region is relatively weak. Temperatures in this
region are warmer than -10C, so fine, light snow/flurries will
remain the most impactful precipitation from this feature. No
accumulations are expected.
The remainder of the forecast remains on track with flurries
exiting the region by early morning Thursday and a dry, cool day
to follow.
MRM
&&
.SHORT TERM... (Through Late Thursday)
Issued at 224 PM CST Wed Jan 25 2023
Low pressure has moved into the Ohio Valley this afternoon, and a
weak, but rather chilly surface ridge is building into the Midwest.
The pressure gradient is tightening between the low and a stronger
ridge farther west over the Rocky Mountains, and this tightening
gradient is beginning to produce some gusty northwest flow across
the area. This will pull colder and drier air from the Northern
Plains and Upper Midwest down into the Mid Mississippi Valley
tonight. Temperatures are already in the mid teens to lower and mid
20s across western Iowa and eastern Nebraska, and this airmass will
be pulled across our area tonight. With temperatures well below
freezing moving into the area, any wet road surfaces will be subject
to icing tonight. Icing should be somewhat mitigated by the dryness
of the air as dewpoint depressions will be 5-10 degrees. Gusty winds
should help dry road surfaces as well, but drivers should be
cautious tonight once temperatures fall below freezing.
Along with the colder temperatures, another vortmax is digging into
Missouri this afternoon, right on the leading edge of the colder
air. Most convection allowing guidance is developing showers
associated with this slug of vorticity. A few of the members, most
notably the HRRR, show fairly strong showers with simulated
reflectivity up to around 40dBZ. Most others are not as strong...so
have kept "flurries" in the forecast rather than "snow showers" for
later this afternoon and tonight. If these showers do end up
becoming more robust as the HRRR suggests, they could briefly
produce snow that`s heavy enough to reduce visibilites significantly.
Any shower/flurry activity should have moved out of the area by
Thursday morning. Clouds will persist through much of, if not the
entire day. With persistent northwest flow, the morning`s cold
start in the teens and 20s, and the persistent cloud cover, high
temperatures on Thursday will struggle to reach the mid 20s to low
30s.
Carney
.LONG TERM... (Thursday Night through Next Wednesday)
Issued at 224 PM CST Wed Jan 25 2023
Active northwest flow aloft will persist through Friday before
becoming zonal once again. In the meantime, a shortwave will slide
southeast through the region on Friday. However, main energy will
stay well to our northeast and east, so will mainly see
increasing clouds and possibly some flurries/sprinkles over
portions of west central/southwest Illinois as the shortwave
slides through. Otherwise, Friday will be quite warmer as surface
winds become southerly once again and pickup before veering to the
west by the afternoon as the shortwave exits the region. Highs on
Friday will be in the 40s, around 5 degrees above normal for this
time of year. The warmer air will continue to shrink the snowpack
across the area.
Beyond that, the latest deterministic and ensemble solutions have
better agreement with the weekend system where a deepening trough
over the western CONUS will slide east with a surface low developing
in the lee of the Rockies beginning Friday night. Ahead of the
system, surface winds will back to the southwest to south once again
keeping temperatures above normal through the first part of the
weekend. On Saturday, as the surface low moves east towards the
forecast area, a warm front will develop across northern portions of
MO into central IL. The upper level shortwave associated with the
system will slide east along the warm frontal boundary. There will
be enough lift along the warm front that overrunning
precipitation will develop across portions of northeast MO, as
well as west central/southwest IL during the day on Saturday. This
round of precipitation will start off as light snow, then become
mixed with/and or change over to all light rain by Saturday
afternoon.
By Saturday evening, the surface low will move east through the
forecast area. The associated cold front will usher in colder air as
the winds veer to the north. With some low level moisture and lift
along the boundary, precipitation will develop and slide
southeast across the region. However, some concern about
precipitation type Saturday night through Sunday as the latest
forecast soundings are indicating a loss of ice crystals aloft, so
can`t rule out that the rain will change over to patchy freezing
drizzle, before coming to an end Sunday morning. With limited
moisture, qpf amounts will be on the low side.
As for next week, the latest cluster analysis still indicates
strength, location and timing differences with a system that will
affect the region Monday night through Wednesday. Thus confidence
remains low and will stick with the latest NBM solution which has
low chance POPs and a wintry mix possible.
Byrd
&&
.AVIATION... (For the 00z TAFs through 00z Thursday Evening)
Issued at 508 PM CST Wed Jan 25 2023
The MVFR stratus deck continues to hang onto the region and will
persist through most of the TAF period before the deck begins to
clear central Missouri by the very end of the TAF period. Sites
may bounce around the fuel alternate threshold through the period,
but confidence is high that MVFR will be the dominate flight
category.
Northwesterly winds will continue to be elevated above 10 kts
sustained, and will gust periodically into the upper teens to low
twenties overnight and through most of the day tomorrow. Surface
winds will diminish slightly tomorrow evening.
MRM
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 25 31 23 47 / 10 5 0 0
Quincy 20 26 18 42 / 20 5 0 10
Columbia 20 30 22 47 / 10 0 0 0
Jefferson City 21 32 22 48 / 10 0 0 0
Salem 25 30 19 43 / 20 10 0 10
Farmington 22 32 19 47 / 10 5 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Miami FL
613 PM EST Wed Jan 25 2023
...New UPDATE, AVIATION...
.UPDATE...
Issued at 609 PM EST Wed Jan 25 2023
No major changes to the near term forecast. Latest HRRR guidance
still showers a diminishing line of showers moving across the area
overnight along and ahead of the approaching front, with the
highest PoPs over the NW portion of the forecast area.
&&
.SHORT TERM...
(Rest of today through Thursday)
Issued at 244 PM EST Wed Jan 25 2023
Deep upper-level troughing continues to dominate the short term
pattern across the eastern CONUS this afternoon. Associated cold
frontal boundary with this system is evident on satellite as a thin
line of clouds pushing southeast through the Florida peninsula and
should pass through South Florida very late tonight or early
tomorrow morning. In the meantime, southerly flow ahead of the
approaching boundary has continued in earnest and led to near record
highs in the upper 80s area-wide.
This will be another weak frontal boundary passage for the area with
another thin line of showers and potentially embedded thunderstorms
approaching the area from the northeast early on Thursday. Best
chance for scattered showers and storms will be maximized just
before sunrise hours on Thursday for Southwest Florida and Palm
Beach County. The boundary will begin to dry up and push southeast
through the morning with Broward and Miami Dade counties joining the
party by mid-morning. By the time this boundary reaches Broward and
Miami Dade counties, precip will likely be limited to isolated
showers with the majority of the strongest activity remaining
offshore local waters where instability is maximized. Highs on
Thursday will be significantly lower than today, as we will be
behind the front and flow will return more northerly. Highs are
expected to be in the mid-70s for northern portions of our CWA and
low 80s for southern and coastal areas.
&&
.LONG TERM...
(Thursday night through next Tuesday)
Issued at 244 PM EST Wed Jan 25 2023
As a cold front progresses towards the southeast across the region,
northwesterly winds will become established. This will result in
cold air advection, allowing for a noticeable drop in temperatures
across the area on Thursday night. Temperatures on Friday morning
(subject to change) are currently forecast to range from the mid to
upper 40s near Lake Okeechobee, the lower 50s across Southwest
Florida, and the upper 50s to low 60s along the east coast. Cool and
breezy northwesterly winds will result in lower than usual maximum
temperatures on Friday; maximum temperatures Friday should range
from the upper 60s to lower 70s. It is worth mentioning that
temperatures have trends about a degree or two warmer, perhaps
suggesting a weakening/decoupling of the frontal system upon
approach; however it is still early and this could easily reverse
course. The drier air mass will also act to reduce the amount of
moisture in the lower boundary levels resulting in much less muggy
conditions but there may be just enough moisture left above the
boundary layer to support cloud cover on the north side of the
boundary that will remain to the south of our area.
Breezy and seasonable weather can be expected for the early portion
of this weekend, as a large ridge of high pressure will be in place
across the region resulting in generally benign conditions
continuing. However as this feature pushes eastward, it will act to
shift surface winds to a northeasterly/easterly direction, acting to
gradually moderate the air-mass and allowing a gradual warming trend
to ensue. By Sunday, high temperatures will once again be above
average for this time of year with maximum temperatures forecast in
the low to mid 80s across the region.
After a brief respite from storm systems, a developing surface low
will once again advect eastward across the northern Gulf coast late
weekend into next week. An associated surface cold front will also
move in conjunction with the boundary, but current model guidance
depicts this next boundary remaining to the north of our region
which will keep overall dry conditions across our area for the time
being. With that being said, this is towards the end of the extended
period so confidence is low at this time. Overall, mostly dry and
benign conditions will likely persist through early portions of next
week.
&&
.AVIATION...
(00Z TAFS)
Issued at 609 PM EST Wed Jan 25 2023
VFR to start the 00Z TAF period. Southerly winds ahead of an
approaching front becoming northerly early Thursday behind the
frontal passage. VCSH is in at APF and PBI overnight where rain
chances are highest. Expect MVFR ceilings along and ahead of the
frontal boundary with ceilings improving by late morning into the
afternoon on Thursday.
&&
.MARINE...
Issued at 244 PM EST Wed Jan 25 2023
Southerly winds will prevail over all of the local waters today as a
cold front approaches our region late tonight into Thursday. The
decrease in wind speeds will lead to a lessening of wave activity
today across all area waters. Showers and isolated thunderstorms
will be possible with the frontal boundary late tonight and Thursday
as it pushes through the area. Another period of elevated seas is
likely behind the cold front for the offshore waters of Collier
county late Thursday and Friday and for the Atlantic waters on
Friday and through the early part of the weekend as breezy
northwesterly to northerly winds are forecast over the area waters.
&&
.BEACHES...
Issued at 244 PM EST Wed Jan 25 2023
A high risk of rip currents continues for all East Coast beaches
today before gradually subsiding by tomorrow morning. With the
arrival of the cold front tomorrow, the gulf coast beaches will see
an elevated risk of rip currents Thursday and may be into Friday
with the Rip current risk becoming high once again along the
Atlantic beaches late Friday and through the weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Miami 70 81 62 73 / 10 20 10 10
West Kendall 66 82 60 74 / 10 20 10 10
Opa-Locka 68 81 61 73 / 10 20 10 10
Homestead 67 82 60 74 / 10 20 10 10
Fort Lauderdale 69 80 61 72 / 10 20 10 10
N Ft Lauderdale 69 79 60 72 / 10 20 10 10
Pembroke Pines 67 81 60 73 / 10 20 10 10
West Palm Beach 67 77 58 72 / 20 30 0 10
Boca Raton 68 79 59 73 / 10 30 10 10
Naples 66 73 52 71 / 50 20 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 7 PM EST this evening for FLZ168-172-
173.
AM...None.
GM...None.
&&
$$
SHORT TERM...Rizzuto
LONG TERM....SRB
AVIATION...CMF
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
927 PM EST Wed Jan 25 2023
...New UPDATE...
.UPDATE...
Issued at 854 PM EST Wed Jan 25 2023
Broad upper trough across the Ohio and Tennessee valleys with cold
air aloft. 500mb temperatures drop to near -30 degrees C across
northern middle Tennessee overnight with cold air advection into
the region. The cold air will help steepen the low-level lapse
rates. Model soundings also show deepening low-level moisture just
below 750-800mb. This will allow for scattered showers and
westerly flow will produce enough orographic lift into the higher
elevations.
Temperature profile will continue to become more favorable for
snow overnight and Thursday. Light snow accumulations are expected
across the highest elevations, generally 3kft or higher. 1 to 1.5
inches are possible across the highest terrain tonight and again
Thursday. Due to limited impact over the highest terrain, plan on
holding off issuing a winter weather advisory. However, will issue
a SPS.
Winds have diminished but still breezy out of the west. Made some
changes to hourly temperatures to reflect current conditions.
&&
.UPDATE...
Issued at 419 PM EST Wed Jan 25 2023
Sent as correction to update prelim point temps/PoPs. No other
changes with this update.
&&
.SHORT TERM...
(This evening through Thursday)
Issued at 302 PM EST Wed Jan 25 2023
1. Gusty winds will continue through the daylight hours before dying
off overnight
2. Light snow showers possible overnight into Thursday with minor
accumulations expected in the northern valley, and possibly a few
inches in the mountaintops.
Discussion:
We were a little slow to mix down some of the stronger wind gusts
today, but currently lots of obs measuring 25-35+ mph winds across
the area. Have backed off on the wind speed forecast compared to
earlier forecast issuances, blending in the NAM and HRRR which seem
to have a better handle on wind speeds/mixing at the surface. Will
continue the Wind Advisory and High Wind Warning through this
evening, when gusts should decrease in frequency and intensity as
the LLJ winds decouple.
Moving into the night-time hours our attention turns to the
possibility of light scattered rain/snowfall into Thursday. As the
low pulls out to the northeast the wrap around moisture will
interact with a weak embedded shortwave moving through the Ohio
Valley to create light showers. Will continue with low end PoP
chances overnight and into Thursday with enhanced PoP/QPF totals
along the higher terrain where orographic lift will enhance showers.
Accumulations in the mountains and higher elevations of the
Cumberland Plateau should begin overnight and as temperatures drop
to near/below freezing snow could start to make it to the surface in
northeast TN and southwest VA. Have stayed close to latest
NBM/WPC/HRR forecasts with respect to snowfall totals. Could see
minor accumulations on grassy and elevated surfaces near and north
of I-40 overnight or Thursday, but with temperatures in the 50/60`s
today it should take a while to accumulate on any other surfaces.
Could need a Winter Weather Advisory in the mountains heading into
tomorrow, but certainty on accumulations at the surface anywhere but
the tops of the mountains is still fairly low at this time.
&&
.LONG TERM...
(Thursday night through next Wednesday)
Issued at 302 PM EST Wed Jan 25 2023
1. Lingering high elevation light snow overnight Thursday-Friday
morning.
2. Unsettled weather pattern next week. Couple chances of rain
focused on Sunday and Tuesday.
Discussion:
Other than some lingering flurries in the overnight period between
Thursday and Friday in the elevated terrain, expect a dry start to
the weekend. Friday will be a bit on the chillier side, but we`ll
warm back into seasonable norms thereafter. Saturday will be the
best day in this period, with dry weather before the next unsettled
pattern arrives. On a wider scale, ensembles are in general
agreement about a return to near zonal flow. By Sunday, guidance
shows a strengthening upper jet to our west. In response, modest
warm air advection will promote an overrunning scheme resulting in
widespread light rain across the area during the day on Sunday.
Monday should be dry, though the global models had some lingering
faint signals for light rain, especially Monday morning.
In the latter part of the period, the ensemble means continue to
show fairly good agreement on both synoptic scale flow and also more
rain on Tuesday and Wednesday, so didn`t change PoPs from the NBM.
Accounting for the rain we got this morning, and since the Sunday
system doesn`t look like a soaker, no significant impacts are
expected for now.
&&
.AVIATION...
(00Z TAFS)
Issued at 603 PM EST Wed Jan 25 2023
Plenty of low-level moisture will continue to produce marginal
MVFR to low VFR ceiling conditions throughout most of the forecast
period for all TAF sites. Cold air aloft will help produce fairly
steep low-level lapse rates especially late tonight and Thursday.
Scattered showers can be expected especially for TYS and TRI
tomorrow. Even though surface temperatures will remain in the 30s
to lower 40s, enough cold air aloft to keep precipitation type as
snow or qraupel (granular snow pellets). These showers will reduce
visibilities to MVFR conditions.
Westerly winds will remain windy but slowly diminish to sustained
10-14kts with gusts into the 20s.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 36 45 27 49 / 10 10 0 0
Knoxville McGhee Tyson Airport, TN 34 42 25 43 / 20 20 10 0
Oak Ridge, TN 33 42 25 44 / 20 20 10 0
Tri Cities Airport, TN 33 40 24 39 / 30 40 20 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...DH
LONG TERM....Wellington
AVIATION...DH