Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/31/23
Area Forecast Discussion
National Weather Service La Crosse WI
531 PM CST Mon Jan 30 2023
.DISCUSSION...(This evening through Monday)
Issued at 255 PM CST Mon Jan 30 2023
Key Messages:
- Bitter cold temperatures to end the month.
- Another blast of cold Thursday night and Friday.
- Warmer for the weekend with small chances for snow.
Overview:
Overnight lows ranged from a few degrees above zero over southwest
Wisconsin to -10 to -13 for parts of west central Wisconsin,
southeast Minnesota, and northeast Iowa. The coldest wind chills
were -24 to -28 near Rochester/Eyota, and in Taylor, Dodge, Wabasha,
Winona, and Mower counties.
Water vapor satellite imagery/heights show a mid-tropospheric trough
over Hudson Bay extending southwestward through the Northern Plains
and Rockies toward closed low pressure off the southern California
coast. At 20Z...a 1035mb area of surface high pressure was centered
over southeast South Dakota. This broad area of surface high
pressure extended well into MN/IA. 20Z temperatures were mostly in
the single digits with light northwest winds 5 to 15 mph with a
few patchy clouds. Surface dewpoints were in the single digits
below zero, however to the west, they were more -10 to -20.
Through mid-day Tuesday, the cold air will remain in place, with the
cold air beginning to retreat as the ridge over the West Coast
begins to affect the area with rising heights.
Bitter cold wind chills tonight and Tuesday morning:
There remains some large differences in the MOS guidance tonight
with temperature and dewpoint forecasts. The MAV guidance at
Medford has -22 and the MET, -15. Similarly, the RAP has dewpoint
temperatures plummet to -30 to -38 for dewpoints toward RST. Our in-
house verification shows that the NBM/CONSALL do a good job. This
would put dewpoints in the -10 to -20 degree range. Surface high
pressure passes to our south with light and variable winds becoming
southwest or (southeast at LSE). The 900mb winds are a minimum
through 06Z...then begin to increase from the west to around 20 or
25kts. With fresh snowpack for some and the forecast soundings
showing a strong inversion with good radiational cooling...have lows
of -10 to -20. The winds will be light northwest then southwest,
increasing after 12Z Tuesday. Coldest wind chills drop to -20 to
minus 35, thus have issued a wind chill advisory for the forecast
area through 16Z Tuesday. Temperatures remain in the single
digits and teens for Tuesday with single digit above and below
zero Wednesday morning.
Wednesday Not As Cold, but another Arctic Blast Thursday night and
Friday:
Wednesday, return flow sets up with rising heights and warmer
temperatures with highs in the teens and 20s. Temperatures Thursday
will be similar, however...another shot of cold air arrives with the
current timing of falling temperatures in the afternoon. Patchy
clouds are on tap and there could be some flurries with the surge
of cold air Thursday.
The NAEFS anomalies for Friday are 1 to 2 standard deviations below
normal. The NAEFS ENS are similar...but still more around 2. A 1040
large area of high pressure plunges southward with 850mb
temperatures by Friday morning around -18 deg C. Lows of -5 to -15
are forecast with bitter cold wind chills again of -15 to -30.
A clipper brings a chance for light snow Saturday, but also warmer
temperatures in the 20s and 30s for the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 529 PM CST Mon Jan 30 2023
VFR conditions persist through the TAF period. Patchy high level
clouds move over the terminals periodically, but in general mostly
clear skies with bitterly cold wind chills early tomorrow morning.
Winds shift to the southwest later this evening but remain light
overnight. Winds strengthen to 10-15 knots tomorrow afternoon
with gusts up to 20 knots Tuesday afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Wind Chill Advisory until 10 AM CST Tuesday for WIZ017-029-
032>034-041>044-053>055-061.
MN...Wind Chill Advisory until 10 AM CST Tuesday for MNZ079-086>088-
094>096.
IA...Wind Chill Advisory until 10 AM CST Tuesday for IAZ008>011-018-
019-029-030.
&&
$$
DISCUSSION...Zapotocny
AVIATION...KAA
Area Forecast Discussion
National Weather Service Duluth MN
532 PM CST Mon Jan 30 2023
.DISCUSSION...(This evening through Sunday)
Issued at 234 PM CST Mon Jan 30 2023
Summary: Quite cold wind chills and air temperatures last through
Thursday night of this work week. A warming trend back into the
twenties is possible starting Saturday. Very light snow cannot be
ruled out Tuesday night, Wednesday night or Saturday evening,
although any accumulations are likely to be minimal if anything.
High pressure in the southern parts of the Midwest and low
pressure over the Hudson Bay keep the Upper Midwest in a cold air
regime today. Another night of very cold wind chills is likely
under this synoptic pattern promoting maximized radiational
cooling, especially in northwest Wisconsin tonight. Another
forecast-area wide Wind Chill Advisory was issued as of this
afternoon to cover this hazard tonight and into the Tuesday
morning commute hours.
The high pressure moves eastward tonight and results in winds
becoming westerly in the mid-levels to southwesterly at the
surface. Daytime high temperatures are expected to rebound on
Tuesday into the mid-single digits above zero. Deterministic
guidance is point to some sort of weak 700-500 mb open shortwave
passing over the Northern Plains Tuesday night. Blended high res
guidance shows up to Chance (40% ) PoPs for this passing wave by
early Wednesday morning. Confidence in this solution is not quite
as high though so only a Slight Chance (20%) of snow was added
into southern and central forecast locations for Tuesday night and
exiting eastward into north-central WI by mid-Wednesday morning.
Could see a few different scenarios playing out where these
minimal, but mentionable, PoPs for Tues night decrease even
further in upcoming forecasts.
Overnight wind chill values for Tuesday and Wednesday nights are
expected to be much less severe across the Northland (-5 to -20
for most locations). The MN Iron Range northward into the
Borderlands may dip down into limited coverage of Wind Chill
Advisory criteria each night though.
A weak Arctic front is expected to pass over north-central CONUS
starting Thursday morning. This will result in another significant
push of very cold air into the Northland. Wind chills Thursday
night are likely to be another period of concern for more of the
forecast areas. Wind Chill headlines may be needed in time then
lasting into Friday morning.
Ensemble guidance continues to indicate a mid-level ridge helping
to advect warmer air into the Upper Midwest starting Saturday.
This may mean daytime high temperatures Saturday near 20 above
zero. Snow may then be possible Saturday evening.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 532 PM CST Mon Jan 30 2023
VFR conditions covered the most of the Northland early this
evening with west to southwest winds. There are some VFR with
scattered MVFR ceilings over western North Dakota and eastern
Montana moving east and some of the guidance wants to bring this
into the Northland Tuesday morning. We followed closer to the RAP
which does have these clouds moving into western parts of the
Northland around or after 10Z but it suggests more scattered to
broken. There are also some indications that MVFR ceilings will
develop during the day Tuesday but looking at forecast sounding,
the low level moist layer is rather thin so we just have a
scattered mention and not MVFR ceilings. A shortwave and warm air
advection will bring a chance for light snow Tuesday night but any
accumulation will be light.
There could be a brief period of low level wind shear at KINL late
this evening into the early morning hours but confidence is too
low to include at this time.
&&
.MARINE...
Issued at 205 PM CST Mon Jan 30 2023
Gusty westerly winds in western Lake Superior this afternoon will
further increase this evening as they slowly back to the southwest.
Small Craft Advisories are in effect or will shortly go into
effect this evening for these conditions hazardous to small craft.
Conditions are expected to improve Tuesday evening as winds
decrease and elevated wave heights slowly diminish through Tuesday
night. Westerly winds look to remain below 20 knots Wednesday
before shifting northwesterly and increasing late Wednesday night.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -16 6 -6 14 / 0 0 20 0
INL -18 3 -15 8 / 0 0 0 0
BRD -16 8 -6 15 / 0 0 20 0
HYR -19 8 -4 16 / 0 0 20 0
ASX -13 9 -1 17 / 0 0 30 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Wind Chill Advisory until 10 AM CST Tuesday for WIZ001>004-
006>009.
MN...Wind Chill Advisory until 10 AM CST Tuesday for MNZ010>012-
018>021-025-026-033>038.
LS...Small Craft Advisory until 4 PM CST Tuesday for LSZ140.
Small Craft Advisory until 4 PM CST Tuesday for LSZ141>145.
Small Craft Advisory until 10 PM CST Tuesday for LSZ146>148-150.
&&
$$
DISCUSSION...NLY
AVIATION...Melde
MARINE...NLY
Area Forecast Discussion
National Weather Service Grand Junction CO
440 PM MST Mon Jan 30 2023
.SHORT TERM...(Tonight through Tuesday night)
Issued at 216 PM MST Mon Jan 30 2023
The ongoing storm continues to bring widespread snow to the
northern valleys up into the northern mountains as local
observations and webcams can attest. The cold front remains across
those same northern valleys and continues to slowly drop
southward. Along and just ahead of the front, banded precip has
set up as originally forecast bringing some squally type snow from
about Montrose northward. Snow squall parameters continue to show
squalls possible through this evening as some minor CAPE and
upper level support and midlevel instability will aid in their
development. Something we`ll certainly be keeping an eye on.
As far as current highlights are concerned, no changes in their
regard. Advisories and warnings for the northern valleys and
mountains are still expected to expire at 5PM. Hi-res guidance has
performed well today with regards to the location and timing of
the banded precip setting up and by early evening, this same
guidance is showing a large band of precip setting up over the
Roan/Tavaputs and I-70 corridor with little else to the north. The
current advisories for the Grand Valley and I-70 corridor up
through Vail Pass remain in effect through midnight, again, for
this line of banded precip. The HRRR is a bit less gung-ho than
previous runs while the NAMNEST is full steam ahead. The front
will start losing its characteristics as it reaches the San Juans
and with upper level support starting to wane, 2 to 4 inches (more
for Wolf Creek Pass) looks about right. By Tuesday morning, all
highlights will have ended with some light snow continuing for the
San Juans with maybe an inch or two of new snow accumulation
possible.
Plenty of clearing overnight, especially up north, and strong cold
air advection will bring some bitterly cold temperatures to our
northern valleys. Craig, Hayden, sorry folks, another round of
lows in the -15 to -20F range. Rangely and Dinosaur can expect
lows in the -10 to -15F range while the Uinta Basin will see temps
around -10F. As previously mentioned, light winds will preclude
the issuance of any Wind Chill Warnings but with temperatures this
cold, any slight puff of wind will cause apparent temperatures to
drop considerably. Bundle up, A LOT, if going out tonight or early
tomorrow morning.
For tomorrow then, look for partly to mostly sunny skies (more sun
up north) with more clouds than sun for the San Juans and southern
valleys. Generally light winds will be the rule as height rises
commence indicating high pressure building in. High temps will be
anywhere from to 10 to 20 degrees below seasonal norms.
.LONG TERM...(Wednesday through Monday)
Issued at 216 PM MST Mon Jan 30 2023
Cold dry conditions will envelope the West Slope Wednesday morning.
Widespread subzero temperatures are expected across the region, with
lower elevations hovering around 10 degrees. Fortunately, this cold
outbreak is short-lived. Subsidence under high pressure and the
return of higher sun angles will initiate a warming trend that
should continue into the weekend. Precipitation chances should
remain near nil for Wednesday through Friday too. The first vague
hints at precipitation return in model outputs on Friday evening. A
weak shortwave pushing across the Pacific Northwest looks like it
could produce a few snow showers over the Continental Divide. It
looks like the southward extent of precipitation will probably be
around Vail Pass. Available moisture and confidence are in short
supply on this event, but it`s worth mentioning for Friday travelers
who plan to take advantage of mountain snow sports, etc. Another
Pacific Northwest wave sits in the batter`s circle Saturday and
deterministic models are putting its arrival on the West Slope
sometime Sunday night. Moisture supplies look more substantial with
this event. However, these northwest waves are quick to spend all
their moisture and arrive on our doorstep worse for wear.
Model disparities are pretty wide at this juncture in the long term
outlook. Rather than labor on with pie in the sky snow hopes, it`s
probably best to stick with a general trend for active weather on
Monday and watch the forecast for a troublesome morning commute to
start the week. If guidance holds true, another high amplitude ridge
over the West Coast looks to set up as this wave digs into the
mountain west. Based on recent regimes, I would look out for another
busy northwesterly flow pattern bringing active weather through the
northern mountains early next week. In the meantime, anyone sick of
shoveling snow will find solace in the second half of the work
week`s forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 440 PM MST Mon Jan 30 2023
A nearly stationary cold front remains draped from west to east
across central portions of eastern Utah and western Colorado this
afternoon. Along the front, bands of snow with varying intensity
continue to impact terminals along I-70, especially KRIL and KASE.
This may also impact KGJT and KMTJ over the course of the
evening. Under any bursts of heavier snow, IFR/LIFR ceilings and
visibility are possible. Gusty winds up to 30 kts are possible
too. The front will slowly sag southward overnight and take the
snow bands with it. Thus, snow will likely affect some of the
southern sites as well. Conditions are expected to slowly improve
during the day on Tuesday with most sites returning back to VFR by
Tuesday afternoon.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Winter Weather Advisory until 5 PM MST this afternoon for
COZ001>003-005.
Winter Storm Warning until 5 PM MST this afternoon for COZ004-
013.
Winter Weather Advisory until 11 PM MST this evening for
COZ006>008.
Winter Weather Advisory until 5 AM MST Tuesday for COZ009-010-
012-017.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...LTB
AVIATION...MDM
Area Forecast Discussion
National Weather Service Grand Rapids MI
1021 PM EST Mon Jan 30 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 1011 PM EST Mon Jan 30 2023
The snow showers have for the most part ended as the DGZ continues
to dry out and surface flow becomes divergent. Some clearing has
occurred inland...and the temperatures have responded. Many inland
locations are in the single digits. Meanwhile where the clouds
are...temperatures are mostly in the 10 to 15 degree range. The
latest HRRR suggests we will see further clearing...so areas
closer to the lakeshore should continue to see the temperature
falling into the single digits as well. Below zero readings are
likely inland...and we will likely see some wind chill readings
dipping below -10 degree F late tonight and through daybreak.
&&
.DISCUSSION...(This evening through next Monday)
Issued at 256 PM EST Mon Jan 30 2023
No big storms through the weekend with dry but cold weather and
only some light lake effect snow showers.
Arctic front has come through through this morning with northwest
flow lake effect snow showers expected to last through Tuesday
but these will be limited by inversion heights under 5000 feet.
Expect accumulations today and Tuesday to be around an inch or
two. We will have to watch for any clearing inland tonight as
fresh snowpack and arctic air will allow temps to plummet below
zero anywhere clearing occurs for a few hours.
Flow goes westerly tomorrow night with forecast soundings showing
inversion maintaining a thin stratus deck most of the night along
with light snow showers or flurries. Some clearing is finally
possible by Wednesday and Wednesday night, mostly across the
southern and eastern areas as flow goes southwest ahead of
shortwave trough.
That trough deepens and drives an arctic front through Thursday
with another round of light snow along the front and lake effect
snow showers behind it. Inversion heights are similar to today,
generally around 4000 feet, which will limit accumulations again.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 631 PM EST Mon Jan 30 2023
The snow showers are slowly weakening...but could persist for
a few more hours especially closer to the lakeshore. Any remaining
IFR from these snow showers should be brief. Meanwhile the clouds
were thinning out over interior parts of MI. KLAN and KJXN should
go scattered this evening as the winds diminish which will limit
how far inland the lake moisture gets. We could see the winds
becoming light for KLAN and KJXN as the cold air builds over the
interior. How far west the clearing/scattering out line gets is
unclear. However KGRR and KAZO will be close to the sct/bkn line.
Any remaining MVFR clouds overnight should be situated close to
the lakeshore...which is why we kept KMKG at MVFR through the
period.
&&
.MARINE...
Issued at 256 PM EST Mon Jan 30 2023
No changes to the SCA. Tuesday will see a decrease in winds and
waves under weak surface ridging but the lull may be short as
winds and waves increase again Tuesday night.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 7 AM EST Tuesday for LMZ844>849.
&&
$$
UPDATE...MJS
DISCUSSION...Ostuno
AVIATION...MJS
MARINE...Ostuno
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
926 PM EST Mon Jan 30 2023
.SYNOPSIS...
While last week featured snow and largely above normal
temperatures, this week will feature below normal temperatures
and little in the way of snow. A weak low pressure will bring a
round of light snow this afternoon into tonight, but snow for
the the rest of the week will largely be confined to the
mountains. The real story will be the late week cold snap, when
the coldest air of the season and maybe since 2016 arrives in
the region. Temperatures are expected to fall well below zero
by Friday night along with dangerously cold wind chills.
Temperatures are expected to rebound quickly on Sunday, back to
near-average for early February.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
9:30 PM Update...Light snow continues this evening as a cold
front slowly sags south across the area and a weak areas of low
pressure develops along this boundary over the Gulf of Maine.
Precipitation shield on radar has been variable with periods of
light snow mostly across the north but over the last hour the
trend has been further south with the echoes. Visibilities have
dropped below 3 miles under the heavier echoes and if CAM
guidance is correct, the southward trend in the lower
visibilites should move out of the interior towards the coast by
11 PM. Overall trended snowfall up a little in some areas where
webcams have already shown and 1 to 2".
7 PM Update...Light snow has broken out across most of the area
with accumulating snow currently focused across the Western
Maine Mountains and Northern New Hampshire. Still expecting the
focus of the accumulating snow to shift further south towards
the coast of Maine after 10 PM tonight. Just some small shifts
in the forecast to increase the pops a bit in a few places based
on current radar trends.
We`re starting to see some returns on latest radar imagery as of
over the last couple of hours with BML and HIE now reporting
light snow as of 3PM. The radar will continue to steadily fill
in with precipitation the rest of this afternoon and evening as
lift increases and the column continues to moisten. This is
again provided by yet another weak area of low pressure that
will move across the Gulf of Maine this evening into tonight.
Forecast soundings support Ptype being mostly in the form of
light snow, except perhaps across southern NH where some there
could be a rain/snow mix or even plain rain at times this
evening.
Forecast thinking remains the same with this generally being a light
QPF/snow amount system (approaching a tenth of an inch give or take)
with higher amounts expected to be toward the Midcoast and Kennebec
valley, where amounts of 1-2" possible, locally up to 3". An area of
enhanced forcing is also still being advertised by the HRRR as
well the GFS stretching from southern NH up the Maine Coast and
toward the ME Capitol Region. These are the areas that could see
a brief period of higher snowfall rates from late this evening
into the early overnight hours.
As the low continues its trek through the Gulf of Maine, flow
will switch around to N/NW and start to bring in some drier air
from the north, which will gradually end snow from north to
south. The last of the light snow is expected to clear the
coast by around daybreak. Overnight temps are expected to fall
into the teens across the north while staying generally in the
20s across southern areas.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
The weak low pressure will continue to depart the area with
cold/dry advection as high pressure starts to build into the
region in its wake. However, enough low-level moisture should
remain present for scattered upslope snow showers to continue
through some of the morning hours before the drier air wins out.
Froude numbers suggest some snow shower activity could make it
south of the mountains (mainly from the NAM), but am expecting
mostly more cloud cover than what models are advertising through
the morning before skies clear out by the afternoon. High
temperatures probably won`t make it out of the twenties south of
the mountains, and with breezy NW winds gusting to around 25
mph, winds chills will be in the single digits to teens. To the
north, temperatures in the single digits to teens combined with
the breezy flow will produce wind chills below zero most of the
day (and negative teens) in the evening.
Winds will die off in the evening and overnight as the previously
mentioned high pressure effectively settles right on top of us
Tuesday night. This will set up excellent radiational cooling which
will further be enhanced with snow on the ground, and for this
reason, I have skewed the overnight low temperatures in the
direction of the GFS and ECMWF MOS. So, for northern areas, forecast
lows are in the negative single digits to negative teens, and to the
south, single digits above are expected. I`m not quite as confident
across southern areas with models advertising a mid-level cloud deck
moving through overnight, so I haven`t gone as cool as MOS with this
forecast. Still, low temps across southern areas are still expected
to be mainly in the single digits (maybe staying in the teens should
the clouds hold), but normally cooler spots could still fall below
zero.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
The major story of the long term forecast remains the bitterly
cold air mass set to descend on New England at the end of this
week. After a week of mostly-dry, zonal flow and seasonably cool
temperatures...model guidance continues to suggest with
increasing confidence a potentially historic 48 hour period of
cold Friday into Saturday. While impressive, the stretch is
mercifully limited in duration with temperatures rebounding
toward normal early next week with PoPs returning late Sunday
into Monday thanks to a progressive wave pattern.
Starting Wednesday... high pressure keeps conditions quiet,
although a weak cyclonic component to flow keeps upsloping
clouds with partly cloudy skies elsewhere. A cool airmass of
-17C thereabouts limits daytime warming to the teens and
20s...perhaps touching 30 at the Seacoast. Building heights
overnight might lead to another night of good radiational
cooling in the more sheltered valleys, however an UL jet lifting
into the region may generate too much mixing and patchy cloud
coverage to go all-in on colder solutions... yielding a low
temperatures forecast in the single digits and teens.
By Thursday, low pressure and its attendant over Hudson Bay
Arctic airmass will start moving southeastward. A preceding
surface wave of low pressure will draw a weak southwesterly
flow over New England which will warm temperatures into the 20s
and 30s, however a powerful Arctic front or series of fronts
will crash through the region Thursday night and Friday.
Mountain snow showers can be expected with the front during the
morning, however the incoming airmass will be dry as well with
quickly diminishing PoPs for the day on Friday.
The bowling ball of coldest h850 temperatures descends from
Canada Friday and Friday night, with the apex of coldest
intrusion looking to be sometime around 00-06Z Saturday. While
the worst of it may not come in time for the 00Z upper air
sounding... this should still yield an interesting and
potentially historically significant sounding (more on
climatological context below). Looking to ensembles, t850 < -30C
is a virtual guarantee in the northern and eastern half of the
forecast area with likely odds present even down to the Mass
border.
Sensible conditions are two-pronged: not only with the air
itself be very cold, but gusty northwest winds will make it feel
even colder. Temperatures will follow a non-diurnal trend on
Friday, starting in the teens and 20s early in the morning then
crashing through the day with strong model support for sub-zero
temperatures area-wide by midnight... and colder than -10F
likely for the bulk of the forecast area, except for perhaps
along the Mass border. The coldest ambient air is expected by
Saturday morning with lows in the negative teens and 20s...
perhaps touching -30 near the international border. Temperatures
on Saturday are forecast to remain in the single digits either
side of zero. When you factor in wind chills, given strong and
gusty winds... widespread values of -35 F or lower are
currently forecast Saturday morning with values potentially
reaching as low as -60F across the north. While the windiest
conditions are expected Friday night and early Saturday morning,
blustery conditions on Friday and Saturday will likely still
produce wind chills in the negative teens and 20s at best.
The progressive wave pattern brings building heights and
slackening flow late in the day Saturday, bringing a quick and
merciful end to this cold snap by the time the weekend wraps up.
Radiational cooling Saturday night will bring one final very
cold morning... with lows again below zero Fahrenheit, into the
negative-teens in many interior locations... in spite of warm
advection aloft. Sunday however will be significantly warmer
with highs much closer to average for this time of year, in the
20s and 30s. The next low pressure system approaches from the
northwest late Sunday into Monday with increasing chances for
snow showers.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term...Ceilings are expected to lower to MVFR this
afternoon and into this evening/tonight as a low pressure system
brings yet another round of light snowfall through, also
causing reductions in visibility to mostly MVFR. Restrictions
are expected to be primarily in the low-end MVFR range, but
there still could be a few hours of IFR ceilings and
visibilities. Snow will taper off overnight as the low pressure
moves to our east and a cold front pushes through the area, and
we`ll start to see conditions improve with most sites expected
to be VFR by daybreak Tuesday, except HIE and LEB.
Scattered upslope snow showers and MVFR ceilings are possible
through Tuesday morning with lower potential of LEB seeing MVFR
ceilings as well. Otherwise, VFR for Tuesday and Tuesday night.
Long Term...VFR prevails except for occasional MVFR CIGs in the
mountains (mostly KHIE) through the end of the week. Steady
westerly flow Wednesday increases out of the southwest on
Thursday, with gusts up to 20-25 kts. Winds turn northwesterly
early Friday through Saturday as a bitterly cold airmass
descends on the region, with gusts potentially exceeding 25-30
kts or so.
&&
.MARINE...
Short Term...Winds are expected to pick up late this evening
and overnight as a weak low pressure moves across the Gulf of
Maine with winds gusts approaching 25 kt by mid-morning Tuesday
as the gradient tightens. Have issued a Small Craft Advisory for
the eastern waters and Penobscot Bay through the Tuesday
evening for northwest winds gusting 25 to 30 kt. Winds will
gradually die off through Tuesday night as high pressure settles
over New England.
Long Term...The general westerly clip to flow over the Gulf of
Maine turns slightly southwesterly on Thursday in response to a
wave of low pressure crossing to the north, bringing winds and
seas to near SCA thresholds. A powerful pair of cold fronts drop
through the waters on Friday with winds turning northwesterly.
Gales, building seas, and significant freezing spray are
becoming more likely Friday into Saturday. High pressure nosing
in Saturday night and Sunday will allow seas to gradually relax.
&&
.CLIMATE...
Potential exists for a historical cold air outbreak late this
week. While this event is forecast to be significant with
respect to ambient surface temperatures, long-standing
benchmarks concerning apparent temperatures (wind chills) and
the air mass itself will be challenged. The 00Z Saturday (7 PM
EDT Friday) upper air sounding is the most likely balloon launch
to challenge unofficial records for KGYX with 850 mb
temperatures expected around -30 C. Wind chill values will be
lowest Friday night and Saturday morning and may be the coldest
since a similar event in February of 2016. Records for low
temperatures are less likely to be broken, given past
radiational cooling events with no wind have result in very cold
temperatures for a short time. Cold daytime high temperature
records do show some potential to be broken on Saturday the 4th.
KGYX Sounding Climatology - 850 mb Temperatures *
Min 10th perc. Median
Feb 3 12Z (7 AM Fri) -22.2 C -16.66 C -8.18 C
Feb 4 00Z (7 PM Fri) -23.4 C -16.64 C -8.17 C
Feb 4 12Z (7 AM Sat) -24.0 C -16.62 C -8.16 C
All time record low of -31.7 C
Record Cold High Temperatures
Portland Concord Augusta
Sat 4th 9 (1948) 4 (1908) 6 (1963)
Record Low Temperatures
Portland Concord Augusta
Sat 4th -19 (1971) -24 (1898)-14 (1971)
Sun 5th -13 (1978) -16 (1978) -10 (1996)
Last Date Since High Temperature <= 10 F
PortlandJan 06 2018 (4 F)
ConcordJan 15 2022 (8 F)
AugustaJan 15 2022 (10 F)
Last Date Since Wind Chills <= -35 F *
PortlandJan 04 1981 (-36 F)
ConcordFeb 13 2016 (-39 F)
AugustaJan 16 2004 (-37 F)
More information may be added to this summary as time allows.
* It is important to note that official climate records are NOT kept
for apparent temperatures and upper air soundings, and are therefore
NOT subject to the same rigorous quality control processes as our
normal subset of climatological information.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory from 10 AM to 10 PM EST Tuesday for
ANZ150>152.
&&
$$
SYNOPSIS...
NEAR TERM...Combs/Dumont
SHORT TERM...Combs
LONG TERM...Casey
AVIATION...Casey
MARINE...
CLIMATE...
Area Forecast Discussion
National Weather Service Louisville KY
1050 PM EST Mon Jan 30 2023
...Forecast Update...
Issued at 1049 PM EST Mon Jan 30 2023
Current dual pol products off of LVX show a very well defined
melting layer between 5500 and 7500 feet AGL. This layer coincides
perfectly with the 850-700 mb warm nose depicted on RAP forecast
soundings, and the latest AMDAR soundings. This warm nose had been
advertised well, so things are going as planned as far as that
feature is concerned.
Looking below the warm nose on the low level thermal profile, it
appears the cold layer should be deep enough and cold enough (~3500
feet of sub zero with coldest temps to -5C) for mostly sleet.
However, area reports appear to be mostly freezing rain mixing with
some sleet at times with the heavier rates. Soundings do suggest we
may not be fully saturated up to -10C above the warm layer, so it
may end up being more of a freezing rain combo for a while, until
better/deeper saturation occurs. Temps are mostly running around 31
to 32 degrees across the northern part of the advisory, but those
will continue to fall. As that occurs, more notable ice accumulation
and a change over to more sleet/snow will be possible across the
northern part of the advisory.
Monitoring trends, and p-types as this complex event unfolds into
the overnight.
Previous Update...
Issued at 955 PM EST Mon Jan 30 2023
Wintry precipitation continues move in from the west-southwest this
evening. The main focus has been a band stretching along the Ohio
River from Louisville to Evansville, Paducah back towards
southeastern MO. Observations as well as storm reports from spotters
indicated deteriorating weather conditions across Southern IN,
especially around Dubois county where reports of traffic accidents
were taking place due to icing on local roads from freezing
rain/freezing drizzle. These reports along with growing consistency
in the CAMs of a narrow band of snow/sleet/freezing rain setting up
along the Ohio River decided to expand the current winter weather
advisory to include Dubois, Orange, Washington and Clark counties in
southern Indiana until 1 pm EST/ Noon CST. While confidence has been
growing of impactful wintry precipitation overnight into tomorrow
morning across the region for all those under the winter weather
advisory, precipitation types and amounts remain the main challenge.
While confidence has grown with model consistency on the development
of a precipitation band across southern IN/northern KY the type of
precipitation remains a challenge. Increased snow amounts across
southern Indiana ranging from a coating to a half inch with isolated
locations potentially seeing an inch of snow. While model soundings
this evening look good for mostly snow, AMDAR soundings out of SDF
has a nice warm layer around 850-700mb indicates sleet mixed in
can`t be ruled out as well as pockets of freezing rain.
Other than the changes to the locations along the Ohio River into
Southern Indiana, the rest of the forecast remain on track with the
main key messages remaining:
* Wintry Mix expected to continue overnight into tomorrow morning
* Sleet/Snow/Freezing Rain accumulations in the overnight hours will
lead to travel impacts during the Tuesday morning commute
* Highest ice accumulations of 0.1-0.2 inches are expected along and
south of the WK/BG Parkways, highest snow/sleet accumulations of
up to one inch are expected along and north of the Parkways into
Southern Indiana along the Ohio River.
.Short Term (Now through Tuesday)...
Issued at 330 PM EST Mon Jan 30 2023
...Wintry Mix Overnight, Impacts to Morning Commute Expected...
Key Messages...
* Wintry Mix expected to begin moving in tonight after 8 PM EST,
continuing into Tuesday morning
* Sleet/Snow/Freezing Rain accumulations in the overnight hours will
lead to travel impacts during the Tuesday morning commute
* Highest ice accumulations of 0.1-0.2 inches are expected along and
south of the WK/BG Parkways, highest snow/sleet accumulations of
up to one inch are expected along and north of the Parkways
Discussion...
Complex forecast for the short-term period as our next wave of
wintry precip moves through the area tonight into Tuesday morning.
In the mid and upper levels, WSW flow will remain in place across
the region with subtle mid-level energy rippling through during the
overnight period. At the surface, Arctic front will be to our
southeast extending from the Mid-Atlantic down into the Deep South,
with steady northerly flow at the surface causing our temperatures
to steadily decline into Tuesday. By Tuesday morning, expect temps
to range from the lower 20s across southern IN to the lower 30s
across southern KY.
Isentropic lift will increase after 31/00Z tonight with precip
overspreading the area from west to east, although initially expect
the main area of precip to remain across southern IN and north-
central KY. While all precip types will be possible, expect the
predominant p-type to walk a fine line between snow and sleet along
and north of the WK/BG Parkways. Model soundings indicate a subtle
warm nose will be possible between 850-700 mb as surface temps will
be in the 27-32 degree range. Snow and sleet accumulations of up to
one inch will be possible along and north of the WK/BG Parkways
although the presence and strength of the warm nose across the
northern half of the CWA will have a large impact on accums. If the
subtle warm nose pans out, would expect lower snow amounts with
higher sleet accounts but if the mid-levels end up being a degree or
two cooler, higher snow amounts (and less sleet) would be possible.
Also worth noting that some of the hi-res guidance is indicating the
possibility of some banded snow along the I-64 corridor with locally
higher accumulations of 1-2+ inches not out of the realm of
possibilities.
As we move towards the 31/03-06Z time frame, precip will then begin
to intensify across central and south-central KY. Model soundings
indicate the 850mb warm nose will be more pronounced across central
and south-central KY, leading to increased potential for freezing
rain and ice accumulations. P-type will likely start as a cold rain
across southeastern portions of KY as surface temperatures are
expected to be in the mid 30s initially (roughly Scottsville, KY to
Richmond, KY), whereas points northward will be mainly a freezing
rain/rain/sleet mix. As temperatures continue to fall near or below
freezing overnight though, expect the rest of central and south-
central KY (save for the Lake Cumberland region) to transition as
well to the wintry mix of freezing rain, rain, and sleet. Overall,
ice accumulations of 0.1-0.2 inches will be possible along and south
of the WK/BG Parkways, although with surface temperatures hovering
right at/below freezing, slightly warmer surface temps would result
in decreased ice accums with longer periods of plain cold rain.
Main precip shield will then gradually exit from NW to SE between
31/09-15Z as drier air works its way into the mid-levels. The lower-
levels will remain saturated and as we lose saturation into the DGZ
(and therefore ice nucleation in the clouds), drizzle and freezing
drizzle will be possible across the area and could cause additional
very minor ice accums into the afternoon.
.Long Term (Tuesday Night through Sunday)...
Issued at 250 PM EST Mon Jan 30 2023
==========================================
Synoptic Overview
==========================================
Pattern aloft over the CONUS will remain progressive and wavy with
several perturbations moving through. Split flow pattern out west
will be noted with a fast northern stream pushing through the
northern US. In the southern stream, a baroclinic zone will set up
from TX northeastward to the Mid-Atlantic. This zone will feature
above normal precipitation through the end of the week before the
northern stream pushes south and suppresses the southeast ridge. For
the Ohio Valley, a few disturbances will affect the region in the
early-mid week time frame followed by drier pattern for the end of
the week and into the weekend. The few disturbances that move
through our part of the world will feature added complexity due to
low-level thermal profiles which could promote more mixed wintry
precipitation.
==========================================
Meteorological Discussion and
Sensible Weather Impacts
==========================================
Tuesday Night through Thursday Night...
Surface high pressure is forecast to be in the vicinity of Chicago
Tuesday evening but will drift southeast toward Richmond, IN by
Wednesday morning. Low-level northeast flow will be present over
the region and temperatures should dip into the low-mid 20s over
southern IN and the northern half of KY. Upper 20s will be found
primarily across southern KY. A southern stream perturbation will
move northeastward and will push into the TN Plateau overnight. As
mentioned previously, the trend in the last few days in the
modeling show this wave passing further south of the region than in
previous runs. The Euro/Canadian are in pretty good agreement here,
though the GFS continues to show its bias of producing very light
QPF over a larger area. Current thinking is that a wintry mix will
be possible over our southern two tiers of KY counties. Soundings
suggest freezing rain and sleet here with generally light amounts.
If current trends continue, another Winter Weather Advisory will be
required for this area. Further north, soundings suggest low-level
stratus and the potential for some light freezing drizzle. This may
occur as far north as the WK/BG Parkways. Overall, this threat is a
bit lower in the latest runs, compared to previous ones, but we`ll
continue to watch.
Wednesday should feature a generally cloudy day with temperatures
warming into the mid-upper 30s with a few 40s down near the KY/TN
border area. Another weak disturbance may affect the region
Wednesday night and into Thursday. The Euro and GEM are much further
south on today`s runs, while the GFS is a bit further north. Given
the trends in the models of the northern stream starting to become
more dominant, not overly confident in the GFS solution here. For
now, will trend PoPs downward slightly to indicate the drier trend
from the Euro/GEM. Thermal profiles here pretty marginal here, but
temps could be close enough for yet another wintry mix, especially
on the northern edge of the precipitation shield. Highs Thursday
are expected to top out in the lower 40s. Lows Thursday night will
be in the low-mid 20s.
Friday through Monday...
By late week, current data trends continue to show drier and calmer
conditions for the area. The northern stream looks to carve out a
broad trough over the eastern US with high pressure building into
the region from the northwest. As the weekend wears on, the flow
will likely transition over to a more zonal flow pattern as we head
into early next week. Highs on Friday in the mid-upper 30s with
lows in the upper teens to lower 20s. Highs on Saturday will
moderate slightly with highs in the low-mid 40s over southern IN and
northern KY and upper 40s over southern KY. Highs on Sunday look to
warm into the upper 40s to near 50 with similar readings expected on
Monday.
==========================================
Forecast Confidence
==========================================
Forecast confidence in the first part of the extended (Tuesday night
through Thursday night) remains generally low given the uncertainty
about the track of the system. Forecast for the Friday-Monday
period is generally medium-high given the good model agreement.
&&
.Aviation (00Z TAF Issuance)
Issued at 620 PM EST Mon Jan 30 2023
A mix of wintry weather set to arrive later this evening will cause
impacts to flight categories through much of tomorrow. Already
seeing IFR/LIFR conditions at HNB/LEX/BWG, and we`ll see conditions
deteriorate at SDF in the next few hours. Ceilings will be on the
border between IFR and LIFR for much of the night, with different
precip types at each terminal. There has been little change from the
previous forecast, with SDF/HNB expected to see mostly snow or
snow/sleet mix. Guidance continues to suggest a brief period of
heavier snow bands possibly impacting SDF between the 03-07z time
frame tonight. BWG and LEX will get a full mix of precip types, but
BWG still appears have the best chances for freezing rain as the
dominant precip type tonight. Ceilings will remain in the IFR range
by tomorrow morning, though some scattering out of the cloud deck
may result in HNB returning to VFR by the afternoon hours.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Winter Weather Advisory until 1 PM EST /noon CST/ Tuesday for
KYZ023>031-033>043-045>049-053>057-061>067-070>077.
IN...Winter Weather Advisory until 1 PM EST /noon CST/ Tuesday for
INZ076-077-083-084-089>092.
&&
$$
Update.........BJS
Short Term.....JML
Long Term......MJ
Aviation.......CJP
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
721 PM EST Mon Jan 30 2023
.SYNOPSIS...
An active, wet weather pattern is expected across the area for
the coming week. High pressure briefly builds into the area
tonight and tomorrow before multiple waves of low pressure bring
unsettled weather for the rest of the work week. High pressure
then builds back into the area Friday night and Saturday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1900 Monday...Story of this shift will be watching obs for
potential issuance of dense fog advisories. Areas along the OBX
from Ocracoke N have dipped down to 2mi or less VIS already,
having touched 1/4mi briefly, but have since come back up above
that threshold for dense fog advisory.
Previous Discussion...As of 330 PM Mon...Latest analysis shows
a 1015mb low, per RAP analysis, several miles off the coast of
Cape Hatteras and lifting further out to sea as very weak high
pressure attempts to build over the mid- Atlantic, all under a
belt of fast-moving mid-level westerlies. A special 15z MHX
sounding revealed a shallow but pronounced low-level frontal
inversion, which has kept an expansive deck of low stratus
socked over our entire FA.
Clouds are expected to gradually break starting early tonight
over the coastal plain as drier air works its way across the
region. However, as high pressure gradually strengthens over the
area and strengthens the low-level inversion, widespread fog is
anticipated to quickly fill in with light winds and freshly
moistened soils. Guidance today has continually pointed to at
least locally dense fog, and Dense Fog Advisories are possible
for the FA early tomorrow morning.
Low clouds and fog will keep the diurnal curve relatively flat
tonight, with temperatures bottoming out in the upper 40s north
of Highway 264 and 50s for the rest of the FA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
As of 345 PM Mon...With weak mixing and a shallow but fully
saturated low-levels fog will be slow to lift. Hi-res guidance
soundings indicate low stratus will continue hang on through
much of the day tomorrow, but mainly dry weather is expected
until late afternoon and evening as all layers above roughly
900mb are quite dry.
Two distinct features will drive the precip chances, the first
being a wave of low pressure riding along the frontal boundary
that pushed through today (which will be decaying tomorrow).
Model trends have pointed to any precip with this feature
remaining offshore, but a slight chance of some rain across the
Crystal Coast is not out of the question. The second, and more
probable feature, will be the cold front currently impinging on
the Appalachians expected to migrate towards the Carolinas late.
The best dynamic lift across the mid-Atlantic will not coincide
with the deeper moisture further south, but some light rain is
possible closer to northeastern NC.
Low clouds again keep the diurnal curve depressed, with highs in
the upper 50s to low 60s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 3 AM Mon...High pressure briefly builds in through
Tuesday but a progressive and wet pattern continues through the
remainder of the week with upper ridging centered across the
southeast Gulf of Mexico and western Caribbean bringing near
zonal mid level flow across the eastern CONUS. A series of weak
shortwave troughs and sfc low reflections will track across the
Southern states and lift along the Carolina coast through the
middle of the week will keep mostly cloudy skies with periods of
rain. The strongest system expected to impact the area Thursday
into Friday as a robust southern stream trough pushes across
the Gulf states and Southeast. High pressure builds into the
area Friday night and Saturday, with another offshore low
possibly impacting the area late weekend. Temps expected to be
near or a few degrees above normal for Tuesday, then drop to
near or slightly below normal through the remainder of the week,
though there may be some variability depending of the eventual
track of the individual low pressure systems. Coldest day still
looks to be Saturday with highs struggling to get into the mid
40s, with 850mb temps 0 to -4C. Still no real ptype concerns at
this time.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /through Tues aft/...
As of 1830 Monday...Stratus trapped beneath a stout low level
inversion still lingering across TAF sites currently. Drying in
the midlevels will work its way through the column and allow
this stratus to scatter out later tonight. Areas of fog are
forecast to develop rather quickly once skies clear leading to
more widespread IFR/LIFR overnight, especially after 05-06z
underneath the strengthening subsidence inversion. Both low
CIGs and fog, likely dense in the early morning hours, are
expected to last into Tues afternoon with very poor mixing
persisting.
LONG TERM /Tuesday night through Friday/...
As of 3 AM Mon...A series of low pressure systems will impact
the area through Friday. Increasing confidence in widespread
sub-VFR conditions through the period. Areas of fog likely Tue
morning, with vsbys slowing improving through low stratus will
likely linger with potential for IFR. Periods of rain likely
Tuesday night through Friday, with best chances Thu into early
Fri.
&&
.MARINE...
SHORT TERM /through tonight and Tuesday/...
As of 1910 Monday...Will be monitoring webcams and limited obs
for potential issuance of Marine Dense Fog Advisories. Fog has
developed just offshore over central waters but a slight uptick
in windspeeds has thinned it out some. Expecting marine dense
fog advisories will need to be issued later tonight for Nern
and Central waters and all inland rivers/sounds after midnight
lasting into at least midmorning.
Previous Discussion...As of 355 PM Mon...Regional observations
indicate mainly northerly winds of 5-10 knots on the backside of
a weak departing low off the coast with seas 2-4 feet. Winds
over the waters will remain northerly at 5 knots or less as weak
high pressure attempts to build over the waters. Only
appreciable uptick in winds will be late tomorrow, mainly owing
an approaching cold front from the north. This will be felt
mainly across the northern waters with northeasterly winds
around 10 kts. Seas through the period hover at around 2-3 feet.
The light winds and building high pres will likely lead to a
setup of dense marine fog tonight into tomorrow morning, with
vsby`s expected to be around 1 mi or less at times, esp for the
interior rivers and sounds.
LONG TERM /Tuesday night through Friday/...
As of 3 AM Mon...Northerly winds will increase to 15-25 kt late
Tue night and Wed with seas building to 5-7 ft. SCA conditions
likely. NE-NNW winds 10-15 kt Thu into Thu night with seas 3-5
ft. Increasing northerly winds Fri 15-25 kt with seas building
to 5-7 ft and another round of SCA conditions likely continuing
into the weekend.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MHX
NEAR TERM...MS/CEB
SHORT TERM...MS
LONG TERM...CQD/OJC
AVIATION...CQD/CEB/OJC
MARINE...CQD/MS/OJC
Area Forecast Discussion
National Weather Service Nashville TN
633 PM CST Mon Jan 30 2023
...New UPDATE...
.UPDATE...
Issued at 633 PM CST Mon Jan 30 2023
Evening sounding from OHX definitely shows a freezing rain
structure, with a warm layer situated just above the surface while
surface temps inch their way toward 32F. We do need some
additional moisture into the dendritic layer, and the latest NAM12
model sounding does, in fact, show a nearly-saturated -10C to -20C
later setting up by 06Z. At this time, temperatures in the NW
corner of Middle Tennessee are in the low 30`s, but the
precipitation is still a few hours away. The HRRR brings the
initial batch of echoes across the Tennessee River between 04-05Z,
and it will likely start off as -FZRA given that temperatures
will be a few degrees below 32F by then. The current forecast
does appear to be on track, so no changes are planned for now.
&&
.SHORT TERM...
(This afternoon through Tuesday)
Issued at 249 PM CST Mon Jan 30 2023
Quite a range of temperatures across the forecast area this
afternoon, with low 60s in our southeast down to mid 30s in our
northwest. Cold front continues to slowly ooze southeastward and
is currently near a Pulaski to Centertown to Jamestown line.
Colder air will continue to filter down into the midstate the
rest of today through tonight, with temperatures expected to fall
to near or below freezing by morning roughly along and northwest
of a line from Lawrenceburg to Lafayette. Next round of rain is
expected to arrive later this evening and continue through
tonight before rapidly ending from west to east on Tuesday
morning between 14-18Z. Where temps will be coldest in our 5
farthest northwest counties tonight, expecting precip to be
mainly light freezing rain with this first wave, and ice
accumulations around one to two tenths of an inch are possible in
parts of Stewart, Montgomery, Houston, Humphreys, and Dickson
Counties. Locations further to the southeast will be warmer with
fewer hours of potential icing, so only a trace up to a tenth of
an inch is possible.
Based on the latest HRRR, HREF, 12Z global models and WPC
guidance, only addition to the Winter Weather Advisory is
Lawrence County as northern parts of that county could see some
ice accumulation. Small portions of extreme northwest Rutherford
and Wilson Counties could also see brief freezing rain but does
not appear to warrant inclusion in the advisory due to the brief
spatial/temporal impact. Precip looks to end sooner than
previously anticipated based on latest models, so the advisory
was updated to end at 15Z Tuesday morning. Temperatures still
appear they will warm several degrees after precip ends during the
day on Tuesday with all areas rising above freezing, which will
help melt what ice does accumulate. However, it`s possible our
far northwest could stay near or below freezing, and if this
occurs icing impacts would be more significant due to limited
melting.
&&
.LONG TERM...
(Tuesday night through next Monday)
Issued at 249 PM CST Mon Jan 30 2023
No rest for the winter weather weary as a second round of rain,
freezing, and possibly some sleet too, arrives Tuesday evening
and continue into the early morning hours on Wednesday. A much
larger portion of the forecast area will see temperatures near or
below freezing Tuesday night, so ice accumulations are possible
in all but our far southeast counties - and another Winter
Weather Advisory will be needed. Greatest icing looks to be
further south with this second wave since QPF will be lighter
across our north, so this second round could be more impactful in
areas such as the Nashville metro. In addition, forecast
soundings show a colder warm nose across our north with this
second event, so some sleet could mix in at times. However, all
of Middle Tennessee will warm well above freezing by late
Wednesday morning/afternoon so any ice will not last long.
A third and final round of rain moves in late Wednesday and looks
to continue through Wednesday night and all day Thursday before
moving out. Luckily, much warmer temps will advect in from the
south, so no wintry stuff is likely with this third round. This
will also be the heaviest rainfall of the three rounds with up to
3/4 of an inch possible. After this precip ends, we look to stay
dry through at least the weekend with temperatures falling to near
or even below normal for Friday through Sunday. A significant
warmup appears likely next week, however, as upper level winds
really strengthen out of the southwest ahead of the next storm
system on the following Tuesday or Wednesday.
&&
.AVIATION...
(00Z TAFS)
Issued at 623 PM CST Mon Jan 30 2023
Evening sounding from OHX definitely shows a freezing rain
structure, with a warm layer situated just above the surface while
surface temps inch their way toward 32F. We do need some
additional moisture into the dendritic layer, and the latest NAM12
model sounding does, in fact, show a nearly-saturated -10C to -20C
later setting up by 06Z. At this time, temperatures in the NW
corner of Middle Tennessee are in the low 30`s, but the
precipitation is still a few hours away. The HRRR brings the
initial batch of echoes across the Tennessee River between 04-05Z,
and it will likely start off as -FZRA given that temperatures
will be a few degrees below 32F by then. The current forecast
does appear to be on track, so no changes are planned for now.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 32 39 30 42 / 80 60 60 20
Clarksville 26 35 27 39 / 90 40 40 10
Crossville 36 44 31 42 / 60 70 60 30
Columbia 31 39 30 41 / 80 60 80 30
Cookeville 34 41 32 42 / 70 70 60 20
Jamestown 33 40 30 41 / 70 60 60 20
Lawrenceburg 33 40 31 42 / 60 60 80 30
Murfreesboro 33 40 30 42 / 80 60 60 20
Waverly 26 34 26 40 / 80 50 60 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 AM CST Tuesday for Cheatham-
Davidson-Dickson-Hickman-Houston-Humphreys-Lawrence-Lewis-Macon-
Maury-Montgomery-Perry-Robertson-Stewart-Sumner-Trousdale-Wayne-
Williamson.
&&
$$
UPDATE.......Rose
SHORT TERM...Shamburger
LONG TERM....Shamburger
AVIATION.....12
Area Forecast Discussion
National Weather Service Shreveport LA
939 PM CST Mon Jan 30 2023
...New SHORT TERM...
.SHORT TERM...
(Tonight through Tuesday Night)
Issued at 928 PM CST Mon Jan 30 2023
Little change over the last few hours as temperatures are only
very slowly falling, but thats with Tyler hanging on to their 33.
The freezing line is also holding in place over NE TX for now,
but another degree or two colder after midnight is not good news.
We continue all the wintry weather products as they are in place
now and through the overnight hours. The HRRR is showing good
initialization over our 3 states now and will be shifting heavier
area over S AR overnight as temperatures fall better here now with
the backdoor swinging open. We still will not see much drier air,
but rather falling while saturated. Looks like in the predawn
hours our AR counties will start to see some icing as well and the
drizzle and the rain remain ongoing with the light fog. No
changes needed to the overnight forecast at this time. /24/
&&
.LONG TERM...
(Tuesday night through next Sunday)
Issued at 410 PM CST Mon Jan 30 2023
Wet and cold conditions will continue through the rest of the week
before drying out and warming up by the weekend across the Ark-La-
Tex. Until then, troughing across the southwest U.S. and ridging
over the Gulf of Mexico will continue to funnel moisture across
Texas into the area with QPF total values of 2-4 inches (with
isolated higher amounts on top of already saturated soils) prompting
a slight risk of excessive rainfall across Deep East Texas into
Louisiana on Wednesday. With the 32-degree isotherm draped across
our northern tier of zones at the temperature minimum on Wednesday
morning, a wintry mix of freezing rain and sleet remains a possible
threat to morning commutes (especially for the Tyler area and
northward into SE Oklahoma/SW Arkansas). That said, the amount of
precipitation and moisture imported from southwesterly flow aloft
will contribute to dew points warming up to stay above freezing
after Wednesday morning, with the winter weather threat
transitioning into a flooding threat through the rest of the day
into Thursday.
Through Thursday night, temperature maximums will remain in the
upper 30s/lower 40s with minimums in the low-to-mid 30s, due to
cloud cover and cold precipitation. The slow-moving trough
responsible for this wet pattern will finally exit the Ark-La-Tex
area by Friday, with long-range guidance suggesting a dry weekend
and warming trend boosting temperature maximums into the mid-to-
upper 60s. Temperatures minimums will remain in the upper 30s and
lower 40s by then, near normal for this time of the year. /16/
&&
.AVIATION...
(00Z TAFS)
Issued at 615 PM CST Mon Jan 30 2023
For the ArkLaTex terminals, this marathon run on IFR is off to a
good start with the end a good day/two away as far as getting
back to MVFR. High pressure to the north is anchored over IA/NE at
1037mb and so far the coldest air has seeped into NE TX and SE
OK, but will see backdooring chill drop across AR into S AR over
the next day of N/NE winds. Meanwhile, the super wet SW flow off
the E Pacific will send in a couple of upper disturbances to ramp
things up late tomorrow and Wednesday ahead of any wrap up. /24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 37 38 34 39 / 60 80 70 80
MLU 37 39 34 39 / 40 60 60 60
DEQ 32 35 31 38 / 80 80 70 70
TXK 34 35 32 37 / 80 90 70 80
ELD 32 35 30 36 / 60 80 70 70
TYR 31 34 32 40 / 60 90 70 90
GGG 34 36 33 38 / 70 80 70 90
LFK 39 43 37 42 / 30 60 60 70
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Winter Weather Advisory until 6 AM CST Wednesday for ARZ050-051-
059>061-070>073.
Flood Watch from 6 AM CST Tuesday through Thursday afternoon for
ARZ059>061-070>073.
LA...Flood Watch from 6 AM CST Tuesday through Thursday afternoon for
LAZ001>006-010>014-017>022.
OK...Winter Storm Warning until 6 AM CST Wednesday for OKZ077.
TX...Winter Weather Advisory until 6 AM CST Wednesday for TXZ097-112-
149.
Flood Watch from 6 AM CST Tuesday through Thursday afternoon for
TXZ097-109>112-124>126-136>138-149>153-165>167.
Winter Storm Warning until 6 AM CST Wednesday for TXZ096-108>111-
124-125-136.
&&
$$
SHORT TERM...24
LONG TERM....16
AVIATION...24
Area Forecast Discussion
National Weather Service Tucson AZ
210 PM MST Mon Jan 30 2023
.SYNOPSIS...A storm system off the southern California coast will
drop southeast then move east across Mexico through Wednesday. This
will bring a threat of showers to different parts of southern
Arizona at different times, tonight through Wednesday. Cooler
temperatures will also spread over the area through Wednesday. Dry
conditions with a warming trend is then expected Thursday through
the weekend.
&&
.DISCUSSION...The long anticipated storm system is currently off the
southern California coast with a few light showers developing over
far western Pima county and areas west and north at this time. The
center of the storm will drop southeast through Tuesday and stall
for a bit south of Yuma. Then when more energy drops down the
backside of the system Tuesday night, the low center will resume is
southeast movement into Mexico Wednesday then quickly move off to
the east.
As the system approaches tonight a band of scattered showers is
expected develop over western Pima county then shift slowly eastward
late tonight into Tuesday. Late Tuesday into Tuesday evening this
band will dissipate in place as the storm resumes its southeast
movement. Part of the question is how far east do the showers make
it. Most guidance would suggest almost making it as far east as the
Tucson metro, but not quite. A few solutions including earlier HRRR
runs pushed it into the metro, the Catalina/Rincons and the Santa
Rita mountains for a few light showers. Only mildly tweaked the pops
on the eastern edge with the final result being a low (20-30%) chance
of showers in the metro Tuesday into Tuesday night. Still talking
light amounts (< 0.10) if showers do occur in the eastern part of
the band. Meanwhile across central and western Pima county amounts
could reach up to a quarter inch (central) to as much as locally
half an inch over parts of far western Pima.
As the storm pushes eastward across Mexico Wednesday, a chance
(20-40%) of showers exists southeast of Tucson with the greatest
threat being southeast Cochise county. The snow level will be around
5,500 feet in the morning rising to around 6,500 feet but given any
precipitation that occurs will be light no accumulations are
expected except over the mountains where a light coating is possible.
Cool, below normal temperatures will spread across the area through
Wednesday with highs as much as 7-10 degrees below normal.
Thursday into the weekend an upper level ridge will bring about a dry
period with temperatures warming into Sunday. Highs on Sunday should
be around 5-8 degrees above normal, meaning most valley areas will
bump into the 70s except the colder far eastern valleys which will
likely peak in the upper 60s.
&&
.AVIATION...Valid through 01/00Z.
Breezy southwest winds will continue through 31/01z when gusts will
cease and speeds will drop to 10 kts or less. Light winds are
expected overnight shifting to the southeast between 31/04z-31/06z.
VCSH will be possible at KTUS and KOLS after 31/15z along with SCT-
BKN clouds at 3k-6k ft AGL. Winds will shift back to the southwest
once again after 31/17z at speeds of 7-10 kts for KTUS/KOLS with
slightly higher winds for KDUG at 10-14 kts gusting 18-23kts.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A weather system will move slowly across the region
into Wednesday. This system will bring cooler temperatures, a chance
of precipitation and higher RH values. Any precipitation that does
occur with this system is expected to be light except across central
and western Pima county where up to half an inch is possible. Dry
and warmer conditions will return late in the week through the
upcoming weekend. There is some potential for another weather system
early next week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Public...Cerniglia
Aviation...Guillet
Fire Weather....Cerniglia
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