Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/01/23
Area Forecast Discussion
National Weather Service Boston/Norton MA
1030 PM EST Tue Jan 31 2023
.SYNOPSIS...
A weak wave of low pressure passing well to our south may result in
brief period of snow south of I-90 with the greatest risk near the
south coast late tonight into early Wednesday morning. Dry and
seasonable weather follows for the rest of Wednesday into Thursday.
Arctic front delivers a dangerously cold airmass Friday into
Saturday with some ocean-effect snow showers across Cape Cod Friday
night into early Saturday. Temperatures rebound quickly Sunday with
continued warming trend into early next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1020 PM Update:
While there isn`t much accumulating snow in the forecast, it
remains a challenging forecast regarding the northern extent of
precip for the overnight/early Wed AM period.
Northerly sfc winds from sfc high over northern New England are
drawing dewpoints into the single digits to low teens southward
to along the Rt 6 corridor into the Hartford- Providence metros,
and this northerly dry drainage flow should persist for the
balance of the overnight. Sfc RH`s in these areas are down in
the 40 percent range, and it`s worth noting that the 00z NAM,
its 3-km iteration and past few HRRR runs are now shutouts.
With exception for Cape Cod and southeast New England, model
soundings show incomplete saturation as well, though it is
possible that seeder-feeder processes from increasing covg of
mid level clouds streaming in from the lower Hudson Valley could
be enough to generate flurries in parts of northern CT and
northern RI.
Though it remains an uncertain forecast, given the drier
dewpoints I did opt to reduce the northern extent of slight
chance PoPs down to the northern-central CT border and into
areas south and east of I-95 and reduced snow totals where PoP
are now sub-mentionable. Some ocean enhancement to snow showers
is reasonable and what light snow we do get should accumulate,
if lightly, on all types of surfaces given subfreezing temps
areawide. Think snow amounts up to an inch still appear possible
across Cape Cod, the South Coast and South Shore.
Will process/digest the remaining 00z suite and assess trends
before determining if further adjustments are necessary.
Previous discussion:
* Coating to 1" snow possible overnight mainly across RI/SE MA with
a low risk for 2" amounts across parts of Plymouth County/Cape
* Any snow that occurs will stick on untreated roadways and impact
the Wed AM commute mainly across parts of RI/SE MA
A weak wave of low pressure emerges off the mid-Atlantic coast this
evening. The upper level flow keeps this weak system well to our
south...but model cross sections do indicate a brief band of mid
level frontogenesis that will possibly impact areas south of I-90
and especially towards the south coast and Cape Cod late tonight.
This will be short-lived and there is some dry air that will need to
be overcome in the boundary layer. That being said; there is enough
lift moisture for a brief period of snow mainly across parts of
RI/SE MA but it also could briefly impact parts of CT.
This snow would mainly occur after midnight with the potential for a
coating to 1 inch of snow. Again...it remains to be seen how far
north this minor accumulating snowfall will reach but there is
likely to be some at least near the south coast and Cape. In
fact...some brief ocean enhancement is possible too across portions
of Plymouth county and Cape Cod where a low risk for localized 2"
snowfall amounts is possible. While any snow accumulations will be
minor...temps will be below freezing. This will allow any snow that
falls to accumulate on untreated roads. So some slippery travel is
possible for the Wed AM commute especially near the south coast and
Cape Cod.
Despite another round of clouds arriving later this evening and
overnight...high pressure across northern New England will allow for
some low level cold air to drain southward. Low temps should mainly
be in the teens to lower 20s...but middle to upper 20s being more
common on the Cape and Islands.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Highlights...
* Any lingering ocean effect light snow showers across the far
southeast New England coast Wed AM come to an end by afternoon
* Becoming mostly sunny Wed with highs mainly in the lower-middle 30s
Details...
Wednesday...
Northerly surface winds coupled with 925T below -10C may allow light
ocean effect snow showers to linger into Wed am across parts of
Plymouth county as well as the Cape/Nantucket. However...departing
weak wave of low pressure and a temporary ridge of high pressure
building in from the west should bring an end to that by lunchtime.
Otherwise...expect plenty of sunshine to develop across most
locations with high temps Wednesday mainly in the lower to middle
30s. Winds will be rather light though so not much of a Wind Chill.
Wednesday night...
A ridge of high pressure will remain in control of our weather
Wednesday night. Relatively light winds and mostly clear to partly
cloudy skies should allow for a good night of radiational cooling.
Low temperatures will mainly be in the teens with perhaps some high
single digits in the normally coldest locations of western MA.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Highlights...
* Dry and seasonably cold Thursday before a shot of dangerously cold
air arrives Friday into Saturday.
* Much milder air arrives for Sunday with continued warming
trend into Tuesday
Thursday and Thursday night...
High pres south of New Eng moves offshore with modest warm advection
resulting in 850 mb temps rising to -4 to -8C. Dry day across SNE
with temps recovering into the mid/upper 30s which is close to
normal for this time of year. Arctic front will likely move through
late Thu night around 09-12z. Expect a dry fropa given limited
moisture.
Friday and Saturday...
Arctic front moves east of SNE Fri morning with strong cold
advection resulting in falling temps all day as 850 mb temps drop to
-24 to -28C by 00z. Temps will be falling through the teens and
single numbers during the afternoon with some subzero temps in the
Berkshires by late afternoon. The arctic air will pour into the
region on gusty NW winds as strong cold advection and steep lapse
rates support 30-40 mph gusts, possibly stronger over higher
terrain. Wind chills by late Fri afternoon will be down to -5 to
-15 in the coastal plain and -15 to -30 over the interior high
terrain.
The core of the arctic air moves in Fri night. There is some
uncertainty regarding the magnitude of this arctic airmass as ECMWF
more extreme than GFS and basically in historical territory.
Interesting that the GEFS mean is 3-5C colder than the deterministic
suggesting that GFS may be too warm. ECMWF probably too cold as it
is forecasting 850 mb temps as low as -37C which is unchartered
territory. The ECENS mean is still impressive with 850T -30 to -34C.
The answer likely lies somewhere in between GFS and ECMWF. Since
this is still Day 3-4 forecast we opted not to make any changes to
the current forecast. So we have lows -5 to -15F across much of SNE,
a bit milder near the south coast with min wind chills -20 to -40F,
coldest in the Berkshires. These are dangerously cold wind chills
with potential for frostbite on exposed flesh in as little as 15
minutes. The peak of the wind will occur through early Fri evening
then the wind should drop off a bit overnight as best cold advection
subsides. Still blustery however through the night and into Sat.
Given that the core of the coldest ir aloft will be lifting out by
Saturday with rising heights, temps should recover into the teens,
except single numbers higher terrain. However, wind chills will only
recover to zero to -10F Sat afternoon, so still bitter cold.
Regarding ocean effect potential, low level trajectory is around 310
degrees which is not favorable and should keep organized bands
offshore. However, given the magnitude of arctic air and extreme
instability sct ocean effect snow showers will likely impact the
outer Cape Fri night into early Sat. Ocean induced CAPES up are to
1000 J/kg and delta T 30-35C which is off the charts so could see
snow showers develop overhead around the outer Cape despite limited
fetch and could see some minor accum.
There is also a significant threat for moderate to heavy freezing
spray over the waters late Fri night into early Sat.
Sunday into Tuesday...
Very quick temp moderation Sunday as increasing SW flow develops
with rapid warming of low level temps. 925T warms to 0-4C by late
Sun which will result in high temps reaching mid 30s to lower 40s.
It will also be windy as 40-50+ kt low level jet develops, focused
across SE New Eng. Mid level trough moves through Sun night into Mon
and there is uncertainty regarding the potential for some showers
developing in this time period, but it could end up dry. Further
warming expected Tue as high pres moves east of New Eng with temps
well into 40s and possibly making a run at 50.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
00z TAF Update...
Tonight...High Confidence.
Mainly VFR. However...a brief round of snow showers are possible
toward daybreak south of the MA Turnpike with the best chance
near the south coast, Cape and Islands. This may result in MVFR
to even brief IFR conditions. Winds will be light from the N.
Wednesday...High Confidence.
Any lingering light snow showers into Wed am towards the
Cape/Islands will come to an end by afternoon. Otherwise...VFR
conditions with just scattered fair weather CU. Light WNW winds.
Wednesday night...High Confidence.
VFR. Light WSW winds.
KBOS Terminal...High confidence in TAF.
KBDL Terminal...High confidence in TAF.
Outlook /Thursday through Sunday/...
Thursday: VFR. Breezy.
Thursday Night: VFR. Windy with gusts up to 35 kt.
Friday through Friday Night: VFR. Strong winds with local gusts
up to 40 kt.
Saturday: VFR. Windy with gusts up to 35 kt.
Saturday Night: VFR. Breezy.
Sunday: VFR. Windy with gusts up to 35 kt. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight...High Confidence.
Low pressure passing well south of the waters tonight coupled with a
high over northern New England will result in NW winds shifting to
the N tonight. Some 20+ knot gusts possible especially across our
northern waters...but think conditions will generally remain below
small craft advisory thresholds.
Wednesday & Wednesday night...High Confidence.
Brief ridge of high pressure builds in from the west Wed into Wed
night. This will keep conditions below small craft advisory
thresholds with winds generally from a NW direction.
Outlook /Thursday through Sunday/...
Thursday: Low risk for Small Craft Advisory winds with local
gusts up to 30 kt. Seas locally approaching 5 ft.
Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Seas up to 5 ft.
Friday: Moderate risk for gale force winds with gusts up to
40 kt. Rough seas up to 11 ft. Freezing spray.
Friday Night: Moderate risk for gale force winds with gusts up
to 40 kt. Rough seas up to 11 ft. Freezing spray, chance of
snow showers.
Saturday: Low risk for gale force winds with gusts up to 35 kt.
Areas of rough seas. Freezing spray, slight chance of snow
showers.
Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas locally approaching 5 ft.
Sunday: Low risk for gale force winds with gusts up to 35 kt.
Seas up to 5 ft. Slight chance of rain showers.
&&
.CLIMATE...
Record Low Temps Sat Feb 4...
Boston-2 in 1886
Hartford -8 in 1965
Providence -2 in 1918
Worcester -4 in 1934
Record Low Maximum Temps Sat Feb 4...
Boston 11 in 1886
Hartford 12 in 1996
Providence 13 in 1996
Worcester 8 in 1908
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...KJC/Frank
NEAR TERM...KJC/Frank/Loconto
SHORT TERM...Frank
LONG TERM...KJC
AVIATION...KJC/Frank/Loconto
MARINE...KJC/Frank/Loconto
CLIMATE...
Area Forecast Discussion
National Weather Service State College PA
1015 PM EST Tue Jan 31 2023
.SYNOPSIS...
High pressure will slowly build over Central Pennsylvania today.
An active southern branch of the jet is expected through the
middle of the week with a storm track well south of the area. A
potent cold front is then likely to sweep southeast across the
region late in the week.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
The main focus overnight will be on a weak wave of low pressure
riding northeast along a quasi-stationary front over the
southeast states. The surface will will track well south of Pa
across North Carolina. However, model guidance indicates just
enough moisture, combined with modest fgen forcing beneath the
right entrance region of an upper level jet streak, to produce a
brief period of some very light snow or flurries across the
southern part of the forecast area. Latest RAP suggests the
best chance for a light dusting of snow will be along and south
of the turnpike and I-81 and come between 06Z-09Z.
Elsewhere, surface ridging and dry air should result in fair and
seasonably cold conditions overnight. Mostly cloudy skies late
this evening should give way to clearing skies from north to
south late tonight, as the wave passes.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Surface ridging and low pwats should ensure fair weather and
light winds across the region Wednesday. Wednesday could dawn
mostly cloudy over the southeast counties in association with
wave of low pressure passing off of the southeast coast. Also,
cold air flowing over Lk Erie could generate some shallow
stratocu across the northwest mountains early. However, model RH
profiles support decreasing clouds through the day, with mainly
sunny skies over all but perhaps Warren County by afternoon.
Model soundings become well mixed Wednesday afternoon to at
least 900mb, where temps between -8C and -10C support highs
ranging from the mid 20s across the higher elevations of the
Alleghenies, to the mid 30s across the Susq Valley.
Surface high pressure is progged to pass off the east coast
Thursday, supplying fair and milder conditions as southwest flow
increases ahead of an approaching cold front. Highs Thursday
should reach the 30s and lower 40s.
All guidance shows a deepening upper trough over the northeast
CONUS late in the week, with a potent cold front sweeping
through Thursday night. Lake effect snow showers and gusty
northwest winds appear likely Friday. However, anticyclonic flow
and relatively low inversion heights signal only light accumulations
across the W Mtns.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pressure settling over the state Friday night should
result in breaking clouds and diminishing winds, with any lake
effect tapering off over the NW Mtns. Have nudged min temps
slightly lower than NBM guidance, given expected conditions that
are favorable for radiational cooling. Have also used the much
lighter CONSAll winds, due to NBM`s known high bias and the
progged position of the surface high directly over Pa by 12Z
Saturday.
Saturday should feature mostly sunny and cold conditions with
high pressure over the area, then a rapid warm up looks likely
late in the weekend into early next week, as the upper trough
lifts out and a more zonal flow floods the region with mild
pacific air. Medium range guidance is in relatively good
agreement with the timing and track of fast-moving shortwaves,
which are currently progged to pass north of Pa late Sunday and
late Tuesday. GEFS and ECENS plumes currently support a slight
chance of rain/snow showers across the NW Mtns late Sunday with
a trailing cold front. The plumes indicate a better chance of
rain showers late Tuesday associated with another cold front
passage.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
A general MVFR sky covers the area with the exception of KJST
that waffles in and out of IFR at times. Expect this to continue
through the evening and clouds to lower overnight.
The southern half of the state airfields may see -SN overnight
with the best chance at KJST. KAOO, KMDT and KLNS will drop to
MVFR in -SN as well. The overall system is being kept generally
to the south of the area with high pressure to the north. This
will allow for improving conditions to VFR at all sites through
the morning on Wednesday.
Outlook...
Wed aftn-Thu...Generally VFR w/ no sig wx.
Thu night-Fri...Becoming blustery w/ snow showers developing
across N/W.
Sat...Diminishing winds with improving conds N/W; VFR
elsewhere.
Sun...Generally VFR w/ no sig wx.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Fitzgerald
NEAR TERM...Fitzgerald
SHORT TERM...DeVoir/Fitzgerald/Travis
LONG TERM...Fitzgerald
AVIATION...Evanego/Tyburski
Area Forecast Discussion
National Weather Service Grand Rapids MI
1018 PM EST Tue Jan 31 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 1013 PM EST Tue Jan 31 2023
Clearing skies over much of the interior has allowed for
temperatures to drop more than expected. Single digits were common
with even a few sub zero readings. While the HRRR suggests the
entire region will clear out...satellite trends indicate that the
lake effect clouds continue to form and in some areas are
expanding inland. We will feature lower temperatures tonight and a
general expansion of the clouds inland...especially north of a
KLWA to KAMN region.
&&
.DISCUSSION...(This evening through next Tuesday)
Issued at 256 PM EST Tue Jan 31 2023
-- No big storms, but some snow showers/squalls --
Lake effect snow showers will be moving inland and diminishing
this evening as flow goes west and sfc ridging further lowering
inversion heights. Winds going more southwest later this evening
will push the snow showers north as they taper off and end.
Next chance for snow is on Thursday evening as another arctic
front pushes through with the chance for a quick burst of snow in
the vicinity of the strong low level convergence along the front.
Then another period of northwest flow lake effect snow showers for
Friday.
We will have to watch for any clearing Friday night as the sfc
ridging moves through, which would allow temperatures to plummet
well below zero. We saw temperatures fall to minus 17F at the cold
hollow of Leota this morning and the next arctic airmass is just
as cold and perhaps colder.
Temperatures moderate by early next week as the cold high moves
east and southerly flow develops with moisture return ahead of the
next front with chance of rain or mixed precip by Monday night
and Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 653 PM EST Tue Jan 31 2023
Lake effect clouds continue to stream into some of the TAF
sites...mainly north of KAZO. The west southwest flow was favoring
these TAF sites for the clouds. What snow showers/flurries that
are out there will continue to diminish through the remainder of
the evening. The tops of the clouds still reaches into the lower
end of the DGZ tonight so they flurries may not completely go
away. The MVFR clouds will likely persist for a few more hours
where they are at. The low level flow is shown to back to the
southwest Wednesday...which should favor the lake effect clouds
pivoting north and west with time...with some clearing possible
even for KGRR.
&&
.MARINE...
Issued at 256 PM EST Tue Jan 31 2023
SCA issued for this evening into Thursday evening with sfc
pressure gradient resulting in strong west to southwest winds with
gusts to 30 knots through the period. Strong winds along an arctic
front Thursday evening may need a Gale Warning. Freezing spray at
times as well through the end of the week.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 7 PM EST Thursday for LMZ844>849.
&&
$$
UPDATE...MJS
DISCUSSION...Ostuno
AVIATION...MJS
MARINE...Ostuno
Area Forecast Discussion
National Weather Service Houston/Galveston TX
957 PM CST Tue Jan 31 2023
...New UPDATE...
.UPDATE...
Issued at 929 PM CST Tue Jan 31 2023
Just some quick thoughts on trends & the latest 00z HREF member
data. At 9pm, freeze line generally situated generally north of a
Burton-College Station-Madisonville-Grapeland line. ARW has
seemed to have a decent handle on temps the last several hours. By
morning it depicts the 32F line north and west of a Grapeland-
Columbus line. Precip-wise, HRRR seems to have lined up decently
with the precip trends since earlier today, though the latest 00z
HREF members are all fairly close.
A present lull in the precip is being observed. One can see some
incoming moisture transport on area radars along the mid & upper
Tx coast. Look for some of this to eventually "consolidate" into
a band of precip roughly along the I-10 corridor from Columbus
into the Hill Country in the coming hours and trek east northeast
across our northern 2 tiers of counties after 2-3am into the
mid & late morning hours Wed.
I think the current Warning/Advisory area is sound based on trends
and available guidance. Also, latest FRAM guidance does support
the current configuration with the Warning area potentially seeing
the more significant ice threats. Toyed with adding Grimes County into
the Warning area (mainly for the northern parts). However, will defer
to the midshift and keep an eye on radar/temp trends. Of course,
the majority of this all will depend on where the freeze line is
situated. Rates/downpours too high might actually transport some
of the warmer temps just above the surface downward, but guidance
doesn`t generally show much of that. Otherwise, a cold damp night
elsewhere with slow warming temps areawide beginning in the late
morning hours.
In short...think the fcst is in pretty good shape and just made
minor cosmetic tweaks which mixed in some of the newest HREF
guidance to the previous fcst. 47
&&
.SHORT TERM...
(This evening through Wednesday Night)
Issued at 241 PM CST Tue Jan 31 2023
The overall theme for the short term forecast is disgusting.
Before getting into the freezing rain forecast, let`s talk
temperatures. Burleson, Brazos, and Madison We will be watching counties
will be dropping below freezing this afternoon and will likely
not climb back above freezing until tomorrow afternoon.
Temperatures tonight will be falling to or below freezing for
areas north of I-10 and west of I-45, and also for areas north of
Lake Livingston. South of I-10 and east of I-45 will drop into the
mid to upper 30s. Those looking for a warm up on Wednesday will
need to go to Florida as high temperatures here will be in the mid
to upper 30s across the northern Brazos Valley and up through
Houston County and then low to mid 40s for most of the area. The
temperature graph for Wednesday will flatline as thick cloud cover
will keep low temperatures Wednesday night just be a few degrees
lower than the high temperature of the day.
Now let`s get into the meat of the freezing rain. Temperatures will
slowly fall below freezing at the surface across the northwestern
corner of the region through this afternoon. However, this will be a
very shallow cold air layer with above freezing temperatures above
925mb (peaking at 10C at 850mb). The potential for freezing rain
will persist for the northern Brazos Valley through late Wednesday
morning, but may also see some isolated -FZRA Wednesday night. No
change to the warning/advisory configuration was made with Winter
Storm Warnings in effect through Noon Wednesday for Brazos,
Burleson, Washington, and Madison counties with Advisories in effect
for Colorado, Austin, Waller, Grimes, Walker and Houston counties.
There is the potential for Burleson, Washington, and Brazos counties
to see Advisories Wednesday night, but the potential is so low that
I am not extending the products at this time. Up to 0.15 to 0.2" of
ice accretion in the northwestern portion of the warned area is
possible with a light glaze to less than 0.1" is expected in the
northwestern portions of the counties in the advisory.
There is a possible solution where we do not get as much ice
accretion as expected due to rainfall, especially in more moderate
rain rates, pulling that elevated warm layer down towards the
surface. This would keep the rain droplets from supercooling - thus
no freezing rain. This isn`t the most likely solution, but something
to keep in the back of our minds going into late tomorrow morning
when rain rates may increase a bit.
Speaking of rain, we also have the potential to see some locally
heavy rainfall across the northern half of the region beginning
Wednesday night and Thursday. Generally up to 1 to 2 inches is
expected with isolated high amounts. WPC has placed the areas along
and north of I-45 in a Slight Risk for Excessive Rainfall for
Wednesday night. This amount of rainfall would normally not amount
to any impacts, but between the already saturated, cold ground any
rainfall may lead to minor flooding in areas of poor drainage. Minor
river flooding is also possible in spots along the Trinity and San
Jacinto rivers as well as already high bayous in northern Harris and
Montgomery counties.
Fowler
&&
.LONG TERM...
(Thursday through next Monday)
Issued at 241 PM CST Tue Jan 31 2023
We will be watching showers and thunderstorms and the risk of locally
heavy rainfall move off to the east as the day progresses on Thursday
as the coastal low heads on out of the area. Much drier air will filter
into the area behind this system as surface high pressure builds in
from the north. A dry forecast is in store for the area late Thursday
night through Monday with north winds at the start of the period becoming
mainly east to southeast over the weekend. Strengthening south to southeast
winds at the start of next week can be expected.
For temperatures, if you like a warming trend you will like this. Highs
in the 40s/50s on Thursday will be in the 50s Friday, in the 50s/60s
Saturday, in the 60s Sunday and in the 60s/70s on Monday. Inland lows
will be a little slower to rise, with readings in the 30s Friday and
Saturday and in the 40s Sunday and Monday.
42
&&
.AVIATION...
(00Z TAF Issuance)
Issued at 550 PM CST Tue Jan 31 2023
Will be keeping with the mostly IFR/LIFR conditions already in the
forecast for this package (and perhaps through these next few days
as it currently stands). Main issue will be with the timing of the
mention of precip...with precip type as an issue for the northern-
most terminals (CLL/UTS). But that being said, will be keeping the
current timing in place along with the mention(s) of wintry precip
(-FZDZ/FZRA) just for the northern sites. Moderate and occasional-
ly gusty N winds this evening (12-16kt/G20-224kt) should weaken as
we head into the overnight hours with N/NE winds expected tomorrow
as the coastal low develops to our south. 41
&&
.MARINE...
Issued at 241 PM CST Tue Jan 31 2023
Areas of fog will remain possible into Thursday morning. Visibilities
will vary, though it could be around 1 mile at times. Otherwise, mainly
moderate north to northeast winds can be expected through Thursday as
a coastal storm system organizes and moves up the coast and then eventually
off to the east. Caution and/or Advisory Flags will be needed. Before
the system moves on out, expect periods of mainly light rain with the
possibility of showers and thunderstorms mainly Wednesday night through
Thursday morning. Drier but breezy conditions are expected Thursday
night and Friday in the wake of the system (again, Caution and/or Advisory
Flags will be needed). Lighter east to southeast winds along with lowering
seas can be expected over the weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 31 37 35 46 / 70 80 80 70
Houston (IAH) 37 43 40 49 / 30 70 70 80
Galveston (GLS) 45 49 47 54 / 30 60 60 80
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Winter Weather Advisory until noon CST Wednesday for TXZ163-177-
198-210>212.
Winter Storm Warning until noon CST Wednesday for TXZ176-195>197.
GM...Small Craft Should Exercise Caution through Wednesday afternoon
for GMZ330-335.
Small Craft Advisory until 3 PM CST Wednesday for GMZ350-355.
Small Craft Advisory until 6 PM CST Wednesday for GMZ370-375.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
935 PM EST Tue Jan 31 2023
.SYNOPSIS...
A ridge of high pressure will keep any active weather over the
next few days to the south and deeper into Kentucky. A warming
trend through Thursday will be reversed as high pressure in the
Upper Midwest pushes in sharply colder air on northerly flow.
The high will cross the region and settle in the Mid Atlantic
early Saturday, with rebounding temperatures in southerly flow
expected for the Ohio Valley afterwards.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Surface high pressure will continue to build southeast into our
region overnight while a weak weather system passes by to our
south. In fact, latest HRRR and NAM 3 km continue to indicate
that our far southeast may get clipped by a little light snow.
Will continue with low PoPs in this area. Otherwise,
considerable cloudiness will thin as we head toward morning.
Colder air will filter southeast overnight. This will result in
lows ranging from the single digits northwest to near 20
southeast.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
The surface high will bring sunny skies if not much warmer
weather on Wednesday, with highs ranging from the mid 20s in the
northwest to the mid 30s over Kentucky and far southern Ohio.
High cloud cover will stream in from the southwest as a
longwave trough in western TX creates a strong westerly flow.
Energy in this stream will develop a stalled front over the
northern Tennessee Valley on Thursday. Wed night lows will
should be in the 20-25 degree range.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
The long term period is shaping up to feature a fairly quiet
stretch of weather locally... particularly for this time of the
year. Anomalously deep troughing will evolve over the interior
NE CONUS into ern Canada for the end of the workweek as the last
in a series of S/Ws gets pulled E across the SE CONUS, shunting
the shield of accompanying pcpn with it as we progress into
Friday.
At the sfc, a cold front will track nearly directly N-S through
the OH Vly Thursday evening/night, but without much antecedent
moisture or LL convergence to work with, it should be mainly
pcpn-free. Cannot completely rule out a few flurries with the
FROPA, but overall moisture availability (both in horizontal and
vertical extent) and lift will be rather meager. Temps will
drop into the lower teens (N) to lower 20s (S) by sunrise
Friday, with only a subtle diurnal rebound by the afternoon of
several degrees across the board. Friday night looks to be
coldest night of the long term period as temps dip into the
single digits (N) and lower/mid teens (S) into Saturday morning.
Radiational cooling conditions, while favorable, won`t be
perfectly ideal as the sfc high will be centered over the ILN FA
Friday evening before quickly drifting to the E through the
night. Sfc winds will respond subtly prior to daybreak,
especially across the W, as the gradient begins to tighten
slightly. There will be a decent diurnal swing by Saturday as LL
WAA becomes established on the backside of the departing sfc
high as temps climb into the 30s/lower 40s amidst increasing
clouds.
Temps gradually warm by Sunday into early next week as the deep
troughing over the ern CONUS eases/moves further away. A quick-
moving S/W is fcst to track through the Great Lakes region on
Sunday, with pcpn associated with this system favored to stay to
the N of the ILN FA at this time. Temps will trend above normal
during this period into early next week, with the next
appreciable chance for pcpn holding off until potentially
Tuesday/Wednesday. Still too much uncertainty at this time range
to speak with any sort of confidence regarding the evolution or
timing of the system toward the end of the long term period,
but it does currently appear that rain chances will increase by
Tuesday.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
For the overnight period, surface high pressure will build
southeast into the region while a weak weather system passes to
the south. Clouds (VFR) early on will gradually decrease from
northwest to southeast. Winds will be from the north around 5
knots.
High pressure will settle across the area on Wednesday. Some
scattered cirrus (high clouds) is expected, otherwise VFR
conditions will prevail. North winds will become light and
variable.
OUTLOOK...MVFR ceilings possible Thursday night into Friday
morning.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Franks
NEAR TERM...Hickman
SHORT TERM...Franks
LONG TERM...KC
AVIATION...Hickman
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1005 PM EST Tue Jan 31 2023
.UPDATE...
Issued at 1005 PM EST TUE JAN 31 2023
The latest HRRR runs have been bringing the main pcpn shield a bit
further north late tonight leading to a higher threat of impacts
from mainly freezing rain and drizzle for our counties north of
the original Winter Weather Advisory. This, combined with ongoing
reports of freezing drizzle, prompted an expansion of the
advisory to all but Fleming County for our CWA. The bulk of the
pcpn then clears out by 12Z in these area but matched up the WSW
with the other one to take us through the morning commute but
could see it cancelled early. With this update, have also added
in the latest obs and trends for the T/Td grids. These updates
have been sent to the NDFD and web servers along with a freshened
set of zones, SAFs, and HWO.
UPDATE Issued at 645 PM EST TUE JAN 31 2023
23Z sfc analysis shows a wavy frontal boundary just southeast of
Kentucky allowing the cold air to seep deeper into the JKL CWA.
This is also prompting low clouds and drizzle for much of the area
- falling as freezing drizzle in places where temperatures are
already subfreezing. The next surge of more significant moisture
is poised to enter the area from the southwest during the next few
hours. Currently readings vary from the upper 20s in locations
near and north of I-64 to the mid and upper 30s in southeast
Kentucky near the Tennessee and Virginia border. Meanwhile, amid
northerly winds of 5 to 10 mph, dewpoints are similar to
temperatures varying from the mid 20s northwest to the upper 30s
in the far southeast. Have updated the forecast to continue the
drizzle through the evening for most of the CWA ahead of the more
substantial pcpn moving up from the southwest. With some of this
falling as freezing drizzle in the north went ahead and extended
the SPS for the areas outside of the WSW through the night with
just trace or a hundredth of an inch amounts of QPF anticipated.
Did also include the current obs and trends for the T/Td grids.
These updates have been sent to the NDFD and web servers along
with a freshening of the WSW, HWO, ZFP, and SAFs.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 337 PM EST TUE JAN 31 2023
Key Messages:
1. Wintry mix returns to Eastern Kentucky tonight through Wednesday
morning.
2. Wintry mix will be possible again overnight Wednesday.
Analysis and Discussion:
Present surface analysis across the region has a departing surface
low with another surface low slowly moving out of the Tennessee
Valley. The surface low moving out of the Tennessee Valley will be
the system to bring more wintry mix to Eastern Kentucky.
Aloft, a 105 knot jet streak is moving through an elongated trough.
The first piece of energy associated with the left exit region has
moved off to the east with another piece of energy thriving off the
right entrance region. This secondary piece of energy will provide
the precipitation tonight. At the surface, cold air left behind from
last night`s system has remained in place with cloud cover keeping
temperatures rather cool through the day today. Temperatures haven`t
climbed out of the 20s across the Bluegrass with temperatures
climbing into the 40s near the VA/TN border. These temperatures have
wreaked a little havoc on the forecast for tonight. A surface low
riding along the jet energy will track out of the Tennessee Valley
through the rest of the day into tonight. Precipitation is expected
to increase in coverage after 00Z with rain transitioning to
freezing and rain and snow through the overnight hours. Forecast
surface track has the bulk of the PoP tracking along and south on a
line from Rockcastle to Morgan county. With thermal profiles
favoring rain changing to freezing rain with snow possible toward
Wednesday morning; opted to issued a Winter Weather Advisory for
areas along and south of that aforementioned line. Areas north of
that line up to the I-64 corridor could also see some instances of a
wintry mix but due to the column being colder, more likely seeing a
light wintry mix at onset before transitioning to all snow;
nonetheless, opted for an SPS in those areas. North of the I-64
corridor will remain dry through this event. In the advisory covered
areas, snowfall accumulations up to an inch with ice accumulations
ranging from a glaze to a tenth of an inch is expected. Little to no
accumulation is expected in the SPS area. Impacts to travel will be
likely especially on untreated roads with impacts become less and
less the further one gets toward I-64. Wintry mix quickly tapers off
from southwest to northeast through early Wednesday morning before
the surface low exits Wednesday afternoon.
There`s a brief lull in activity for Wednesday with temperatures
climbing into the upper-30s for highs. However, another system is
expected to track along the baroclinic zone allowing for another
chance at wintry mix Wednesday night into Thursday. Confidence is
somewhat high with what`s expected with this system but there is
some variability on the track and forecast QPF with this system.
Leaned with a blend of the NBM/GFS/NAM as the ECMWF has been the
outlier. Based on the present forecast, more winter weather
highlights may be needed late Wednesday night into Thursday morning.
.LONG TERM...(Thursday through Tuesday)
Issued at 302 PM EST TUE JAN 31 2023
Key Points:
* A wintry mix of rain, freezing rain, or snow will be possible
into Thursday morning, where some slick spots through the
morning commute could result.
* High pressure brings drier conditions Friday and through the
weekend, with temperatures moderating through the end of the
period.
* Shower chances will be possible Tuesday but confidence is low
given broad model spread.
The extended period will begin under zonal flow aloft, as broad
troughing encompasses Eastern Canada, while a dome of ridging
resides across Cuba and the Caribbean. Further west an opening wave
will be gliding across the Texas Panhandle. At the surface, a
stalled baroclinic zone sits aligned from the Atlantic to the
Okefenokee Swamp and through the Gulf Islands National Seashore. To
our north, a surface low sits entangled within the broad troughing
across Canada where a cold front is extended south through the Great
Lakes and into the Northern Plains. The approaching Southern Plains
low, paired with the frontal boundary across the Deep South, will
allow for moisture to advect in off the Western Gulf where slight
chance to low end likely PoPs start the period off for portions of
the area. There remains uncertainty on p-type during this time, as
thermal profiles leave very little margin for one type versus
another. Generally, snow looks to be better supported for the
northern end of the moisture swath, while freezing rain to rain
further south closer to the Tennessee border. There is also varying
solutions on how far north moisture extends, as the ECMWF and
Canadian have trended drier compared to the more bullish GFS. Have
veered closely to the NBM for now as it was more of the compromise
between the two bounds for PoPs Thursday. As temperatures warm
through the morning, all rain will result by the noon hour.
As the trough axes swings east into the Deep South and the northern
cold front sags south, showers will taper off where a Canadian high
fills in. This will meander through the Great Lakes Friday and the
early weekend where a sharp fall in temperatures will follow post
front (upper 20s to low 30s Friday), followed by a moderation
through the remainder of the extended period (50s to low 60s
Tuesday). Guidance has trended down with a late weekend disturbance
as a shortwave traverses through the eastern half of the
CONUS/Canada. There remains differing opinions between data, as the
GFS/GEFS depict a shortwave progressing across the SE, while others
keep the wave north of the area. Either way, moisture appears to
lack locally, and thus, have veered dry during this time. A late
period trough and approaching surface low will bring the return of
PoPs, though model spread is large leading to low confidence
surrounding the details at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 720 PM EST TUE JAN 31 2023
IFR/LIFR CIGS will continue through majority of the TAF period as
another wave of low pressure, riding northeast along a stalled
front, moves into eastern Kentucky from the southwest. Drizzle
and light rain continue to fall from low ceilings this evening
through the forecast area with even some of this as freezing
drizzle in the north. Look for increasing pcpn falling as a
wintery mix moving back into the forecast area this evening and
continuing through 12Z/Wednesday. IFR or lower CIGS are expected
through the duration of the overnight hours before this round of
precipitation comes to an end from west to east with gradually
improving CIGS. Winds will be generally from the north through the
period at 5 kts or less.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 10 AM EST Wednesday for KYZ050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...VORST
LONG TERM...BB
AVIATION...VORST/GREIF
Area Forecast Discussion
National Weather Service Louisville KY
940 PM EST Tue Jan 31 2023
...Mesoscale Forecast Update...
Issued at 930 PM EST Tue Jan 31 2023
Temps have been nearly steady in the last few hours, with readings
mostly in the upper 20s. Have begun to see a few reports come in of
p-types switching over to all sleet in BWG after previously seeing
freezing rain. It still appears the main wintry event will be from
now to about 7-8z, with the only freezing rain potential being
mainly focused now along the KY/TN state line. For LEX, the airport
has just started reported unknown precip, and we received a report
of all sleet in Anderson County. RAP soundings suggest the warm nose
should erode in the next hour or so, and should see mostly light
snow later in the night.
Guidance continues to suggest that the warm nose should be pretty
much dissolved by now over the I-64 corridor, which is indicative of
SDF reporting light snow at the moment. We have not had many AMDAR
soundings in/out of SDF in about an hour or so, but the soundings
that are available did show the warm nose weakening compared to
earlier in the day. Given the light reflectivity returns off KLVX,
and the persistent RAP guidance showing some light snow
accumulations along the I-64 corridor, decided to issue an SPS for
minor impacts for counties along the I-64 corridor and just north of
the current advisory. With not much change to the forecast through
the rest of the night, did not see a reason to expand the advisory
at this time.
Overall forecast remains in great shape, with the only tweaks needed
being a slight northern shift in PoPs and the SPS addition. Snow and
ice accumulations were updated with latest guidance and there was
little change. Still though, should see some travel impacts through
tomorrow morning, especially on untreated rural roads. Otherwise,
forecast is on track, and updated products have already been sent.
Issued at 715 PM EST Tue Jan 31 2023
An area of moderate to heavy freezing rain is moving into Logan
county at the top of the hour, which could result in a rapid
decrease in conditions. KHOP reported heavy freezing rain about 20
minutes ago. Precip onset as freezing rain lines up with forecast,
with RAP model soundings continuing to show a healthy warm nose over
BWG, with the cold layer below it not being deep enough or cold
enough for precip to refreeze. Temps in BWG and surrounding areas
are in the upper 20s, though colder air just to the west will be
arriving soon. Timing out this area of heavier radar returns off of
KHPX, could see an increase in freezing rain rates at Bowling Green
within 15-20 minutes or so.
Issued at 630 PM EST Tue Jan 31 2023
Conditions remain quiet across our area at the moment, but regional
radar mosaic shows the plume of wintry precip over Western Kentucky
and central Tennessee beginning to close in on our CWA. KPAH has
been reporting unknown precip for the last hour, indicative of some
form of wintry precip ongoing. KHOP has started reporting freezing
drizzle and freezing rain. Coldest air is located over western
Kentucky as well, with low 20s generally west of I-69/I-169. For
central KY and southern IN, most of the region is sitting in the
upper 20s, with only our Lake Cumberland region sitting just above
freezing. AMDAR soundings at SDF continue to show the warm nose
roughly 5500-8500 ft, though still expect it to deteriorate in the
next two hours or so for areas north of the Kentucky Parkways.
Current forecast remains on course, with precip initially falling as
freezing rain before transitioning to more of a wintry mix mainly
for areas between the Kentucky Parkways and the Cumberland Parkway.
Kentucky counties right along the state line with Tennessee continue
to have best chance for freezing rain as the dominant p-type as the
warm nose appears a bit stronger and a shallow cold layer below it.
Still keeping eyes on the northern extend of potential light snow,
which could extend as far north as the I-64 corridor. What could
possibly start as light freezing rain or freezing drizzle, would
likely switch over to snow as the warm layer erodes by 02-03z. A few
limiting factors leaves confidence on the lower side for the
northern extend however. Overall residence time, or duration of
wintry precip/snowfall, appears rather short, and better moisture
will remain south of the I-64 corridor. Additionally, soundings
suggest we may not have great saturation up to the DGZ. However, sfc
temps still in the 20s would result in negative travel impacts even
with light wintry precip. Because of this, may ultimately need a SPS
north of the Winter Weather Advisory for minor snow accums and slick
road conditions for tonight.
.Short Term... (This evening through Wednesday)
Issued at 310 PM EST Tue Jan 31 2023
...ANOTHER BOUT OF WINTRY WEATHER TONIGHT...
============================================
Near Term Now through 700 PM EST
Impacts: Wintry mix far SW
Confidence: High
============================================
In the near term, quiet and cold weather is expected across the
region. Temperatures this afternoon have been kept down on a steady
north wind. Temps across southern IN are in the mid-upper 20s with
upper 20s between the River and the WK/BG Parkways. South of the
Parkways, temps were just below freezing, with the freezing line
down in the Lake Cumberland area. NBM has not initialized well with
respect to temperatures, so have clawed back the near term surface
temp grids to what real-time observations show. While no
significant weather is expected over the next few hours, low clouds
and some patchy fog will be possible, especailly across southern KY.
However, as we approach 00Z (700 PM EST) we should start to see a
wintry mix move into western KY and the far southwest sections of
the LMK forecast area.
============================================
Tonight 700 PM to 700 AM EST
Impacts: Wintry Mix Southern 2/3rds of KY
Confidence: Medium-High
============================================
As we move into the evening hours, the next weather system rounding
the southeast ridge will take aim at the TN Valley and the southern
half of Kentucky. Precipitation should be in progress across far
western KY and this activity will spread east-northeast across the
southern 2/3rds of KY through the evening hours. While forecast
confidence is high that this system will impact the region,
uncertainty exists on exactly how far north the precipitation shield
will get.
The overall setup is a familiar one for the OHio Valley with a
warm/moist airmass running over the top of a pre-existing cold
airmass. The setup is a bit different from last night in that the
cold layer in the lower levels is sufficiently deeper across
southern IN and in KY north of the WK/BG Parkways. As one heads
southward toward the Bowling Green area, the cold layer is not as
thick which will result in mixed precipitation. Looking through
various model soundings, the HRRR and RAP models have continued to
trend slight colder with their low-level thermal profiles. Initial
precipitation should start off as freezing rain or even freezing
drizzle as the DGZ will not be fully saturated. However, as
isentropic lift and moisture advection commence, the column looks to
saturate the DGZ a bit more than previously forecast. As the DGZ
gets more saturated, the freezing rain should transition over to
more sleet and snow through the evening.
In looking at the last few hours of high resolution data, the main
two challenges have been p-type and the northward extent of the
precipitation. Given the recent trends in the RAP/HRRR solutions,
we feel a bit more confident that precipitation will develop
northward to areas just north of the WK/BG Parkway. It`s possible
that further northward develop perhaps as far north as the I-64
corridor will be possible, but not all the data suggests that far
north for development. In this northern area, the initial thought
was for some light freezing drizzle initially and then a change over
to sleet/snow. Given the colder profiles, we still may see an
initial p-type of freezing rain/drizzle, but as the DGZ saturates, a
change over to sleet/snow seems more likely in the BG/WK Parkway
corridor.
Further south, from Bowling Green eastward toward Columbia and
Somerset, the low-level cold layer is not as tall. Model soundings
suggest more of a freezing rain profile initially before going over
to sleet. Profiles along the KY/TN border show a solid warm nose
aloft with the profiles suggestive of freezing rain.
With these changes, we made earlier changes to the ongoing advisory
area and expanded the advisory northward to counties that are along
and south of the WK/BG Parkway. The main thrust of wintry
precipitation looks to be from roughly 00Z through about 07-08Z. As
for amounts, a quick glaze of icing will be possible along the WK/BG
Parkways this evening due to the expected Freezing Rain/Drizzle at
precipitation onset. After the quick change over to snow, up to an
inch of snow accumulation will be possible here before precip
diminishes later tonight. Further south, a mix of icing along with
sleet accumulations looks likely across southern KY. The forecast
will contain up to a tenth of an inch of ice accumulation, but those
values will likely be less along the Cumberland Parkway area and
highest along the KY/TN border. Sleet/snow accumulations of less
than an inch are currently forecast.
While confidence remains low on the northward extent of the
precipitation shield tonight, there is some bust potential here in
the forecast. 18Z 3KM NAM and RAP runs suggest some snows as far
north as the Ohio River. Will continue to monitor the northward
extent of precipitation this evening. The precipitation this far
north would likely be of lighter intensity. However, this snowfall
falling with temps in the upper 20s could result in some negative
travel impacts. A further expansion of the Winter Weather Advisory
could be required in subsequent forecasts.
Once precipitation moves out later tonight, temps are expected to
get fairly cold. Overnight lows across southern IN will be in the
upper teens with lower 20s across northern KY and mid 20s across
southern KY.
============================================
Wednesday 700 AM to 700 PM EST
Impacts: Negative morning commute impacts
Confidence: High
============================================
Precipitation should largely be east of our region by the start of
this forecast period. The day will start off mostly cloudy, but some
drier air will try and advect into the region. This may allow for
some partial clearing across southern IN. Highs on the day will be
in the mid-upper 30s across southern IN with upper 30s across
southern KY.
.Long Term... (Wednesday night through Tuesday)
Issued at 310 PM EST Tue Jan 31 2023
Key Messages...
* Light wintry mix possible across south-central KY Thursday
morning, then mostly dry through the weekend
Wednesday Night - Thursday...
The extended period should begin as mostly dry Wednesday night with
lows bottoming out in the mid 20s to lower 30s. However, PoPs will
begin to gradually increase across south-central KY (generally south
of the WK/BG Pkwys) as we approach dawn as a slug of moisture is
transported into the area ahead of a mid-level trough lifting ENE
out of northern Mexico. Bit of variation between model guidance on
just how far north the better moisture will make it, but in general
model soundings indicate a decent dry layer below 850 mb once you
get north of the WK/BG Parkways, so will keep a dry forecast here.
South of the Parkways, surface temperatures will initially hover
right around the freezing mark at the time of precip onset, and a
wintry mix of freezing rain/sleet/snow will be possible before
transitioning to mainly rain by early afternoon. Overall, QPF is
expected to range from a couple tenths of an inch across the Lake
Cumberland region to a few hundreths of an inch near the Parkways,
with very light ice accumulations possible as well. Precipitation
chances will then be shunted to the east by Thursday evening as the
upper wave moves over the OH Valley.
Friday and Beyond...
Mostly dry weather is then expected for the end of the week and into
early next week as a couple of upper level ridges scoot by overhead.
Temperatures will steadily warm during this time frame with highs in
the lower to mid 30s on Friday then warming into the 50s by next
Monday. Similarly, overnight lows will be in the upper teens Friday
night then warming into the lower 40s by Monday night. Precip
chances may return by Tuesday as a cold front looks to approach the
area, but confidence remains low at this point in time.
&&
.Aviation... (00Z TAF Issuance)
Issued at 615 PM EST Tue Jan 31 2023
The next storm system will push into the region this evening from
the WSW. From observations and area radar imagery, wintry
precipitation has begun to spread over far western KY ranging from
freezing rain, sleet and snow. The main terminals that look to be
impacted by this system are BWG and LEX. Initially we will see
freezing rain at BWG starting near the start of the period until
about 06-08z. There could be periods of sleet mixed in as well. For
LEX, light freezing rain/drizzle will develop closer to around 02z
with mainly sleet transitioning over to light snow around midnight
for a brief period. Conditions will remain IFR with occasional LIFR
with some slight improvement to MVFR after 06z.
HNB and SDF will hold on to MVFR flight categories for a couple
hours at the start of the period then improving to VFR closer to
midnight. All TAF sites look to improve VFR near or shortly after
daybreak tomorrow with winds remaining out of the north overnight
then shifting more out of the NE during the day tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Winter Weather Advisory until 7 AM EST /6 AM CST/ Wednesday for
KYZ026>028-039>041-045>049-053>057-061>067-070>078-081-082.
IN...None.
&&
$$
Mesoscale...CJP
Short Term...MJ
Long Term...JML
Aviation...BTN
Area Forecast Discussion
National Weather Service Nashville TN
640 PM CST Tue Jan 31 2023
...New UPDATE...
.UPDATE...
Issued at 634 PM CST Tue Jan 31 2023
The 00Z sounding from OHX is a classic freezing rain sounding.
Surface temps are just below freezing and the elevated warm nose
peaks at ~6C just above 850 mb. And we have plenty of saturation
throughout the troposphere. This is consistent with the ACARS
soundings we were looking at early. There are plenty of reports of
freezing rain now coming in from across the Nashville metro area
now that the freezing line is east of Nashville. There are reports
of heftier ice accumulations farther west toward Clarksville. We
are even seeing some reports of sleet closer to the Tennessee
River. (The warm nose probably isn`t as pronounced there, so the
melted precipitation is re-freezing before reaching the ground.)
At any rate, the current batch of precipitation that is spreading
across Middle Tennessee is only the first wave. The HRRR suggests
that additional precipitation will affect the mid state throughout
the evening, although maybe not as heavy as what we`re seeing now.
Look for the precipitation to taper off from west to east after
06Z.
&&
.SHORT TERM...
(This afternoon through Thursday Night)
Issued at 235 PM CST Tue Jan 31 2023
Latest surface conditions across middle TN indicate cloudy skies
with no precipitation ongoing. Temps range from the upper 20s
northwest to near 40 along the central and southern Plateau. The
actual freezing line still runs from Portland, through western
Davidson county, to the Linden area. Look for the freezing line to
begin making progress southeastward in the next few hours.
Meanwhile, the next slug of moisture appears to be on the way now
with the precipitation advancing into southwestern TN and crossing
the MS river. This activity is expected to overspread the mid state
between now and 8PM.
The examination of model sounding data still shows a rather
pronounced warm nose at around 750 mb. This should continue to keep
most of the precip as liquid, meaning rain or freezing rain
depending on sfc temps. I will add however, that wet bulb layers in
the northwest in the lowest few thousand feet are rather low and
thus, there is a good chance of some sleet in our northwest.
So for timing, the precipitation will begin in our west around 4 pm
or so, and then reach the Plateau around 8 pm. The beginning time
for the freezing rain will be 4pm in the northwest, 6p-9p elsewhere
west of the Plateau, 9pm-midnight Plateau. the precip will end just
after midnight in the west, 3am central, and just before sunrise
along the Plateau.
For the advisory, I will break it into two areas. Area 1 will
include the Northwest and a few west central sections. This area is
already below freezing and some sleet will be possible in that
northern portion of this zone. Will include up to one tenth of an
inch of sleet accumulation and around one tenth of an inch of ice.
area 2 will include the remainder of the mid state, with one tenth
to two tenths of an inch of ice expected. At this time the area with
the greatest potential for the two tenths amounts appears to be the
west central and southwestern areas. The advisories will be in
effect through 6 am cst Wednesday morning.
Moving on, after a brief break during the day, yet another storm
system will bring another good chance of rain to the area Wednesday
night and Thursday. Most areas will recover with temps warming to
above freezing during the day. However, across our northwest,
freezing rain will again be in the forecast with up to one tenth of
an inch of ice possible For Wednesday night. We may end up needing
another advisory which would be issued later, perhaps. Look for the
precip with this final round of moisture to exit the mid state
Thursday night. There could be some light freezing rain in our south
before the moisture completely exits so we`ll need to watch that
too.
&&
.LONG TERM...
(Friday through next Tuesday)
Issued at 235 PM CST Tue Jan 31 2023
For the extended forecast, will we finally see the sun? Yes, it
looks like Friday we finally will. It will be cold though with highs
only in the mid 30s to lower 40s. The good news though is that the
bulk remainder of the extended looks mostly dry with a warming
trend. Temps will reach 60 degrees or so by early next week. Perhaps
a chance of showers returns but not until next Mon nt/Tues at the
earliest.
&&
.AVIATION...
(00Z TAFS)
Issued at 517 PM CST Tue Jan 31 2023
Poor flying conditions expected through 12Z/Wed. IFR to LIFR
cigs/vis will plague mid-state terminals as light rain turns to
light freezing rain this evening. Ice accumulations of a tenth to
two tenths possible through 08-09Z. Cigs/vis should improve after
15Z/Wed but remain at least MVFR.
Winds will be light (10 kts or less) from the northwest, shifting
to the northeast Wednesday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 29 41 33 43 / 80 0 60 60
Clarksville 22 38 30 41 / 50 0 30 40
Crossville 29 42 33 43 / 90 10 70 70
Columbia 27 40 33 43 / 80 10 70 70
Cookeville 30 41 34 43 / 80 10 60 70
Jamestown 27 40 31 42 / 80 10 50 60
Lawrenceburg 29 41 34 43 / 80 10 70 80
Murfreesboro 28 42 32 43 / 80 10 70 70
Waverly 22 36 30 40 / 70 0 50 50
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM CST Wednesday for Bedford-
Cannon-Cheatham-Clay-Coffee-Cumberland-Davidson-De Kalb-Dickson-
Fentress-Giles-Grundy-Hickman-Houston-Humphreys-Jackson-Lawrence-
Lewis-Macon-Marshall-Maury-Montgomery-Overton-Perry-Pickett-
Putnam-Robertson-Rutherford-Smith-Stewart-Sumner-Trousdale-Van
Buren-Warren-Wayne-White-Williamson-Wilson.
&&
$$
UPDATE.......Rose
SHORT TERM...21
LONG TERM....21
AVIATION.....Unger
Area Forecast Discussion
National Weather Service Shreveport LA
819 PM CST Tue Jan 31 2023
...New UPDATE...
.UPDATE...
Issued at 806 PM CST Tue Jan 31 2023
Current observations suggest that the freezing line runs north
along a line from near Tyler to Mount Pleasant, Texas, into
McCurtain county Oklahoma. Additionally, sub freezing
temperatures have been reported along and north of a line from El
Dorado to Magnolia to near Hope and De Queen. Precipitation
trends have decreased somewhat over the past several hours.
However, very little precip is needed to cause icing on bridges
and otherwise vulnerable surfaces. A number of high res models are
in good agreement that a second burst of precipitation will move
through the region near daybreak allowing for additional ice
accumulations of 1/10 to 1/4 of an inch within the warning and
advisory areas. At this time, ongoing advertised headlines align
well with current trends with no need to expand at this time. /05/
&&
.SHORT TERM...
(This evening through Wednesday Night)
Issued at 326 PM CST Tue Jan 31 2023
The freezing line has managed to backdoor a bit farther SW into SW
AR this afternoon, but has remained nearly stationary across E TX
and SE McCurtain County, with primarily reports of -FZRA mixed
with IP at times across NE TX/SE OK/Nrn sections of SW AR. Much of
the impacts have been to elevated surfaces such as bridges and
overpasses, trees and power lines, with amounts just shy of 1/4"
across Nrn McCurtain County OK as of mid-afternoon. The forecast
remains very complicated in the short term, as the HRRR, which has
handled sfc temps best during this evening, suggest that the
freezing line will continue to drift S this evening and overnight,
into portions of N LA and adjacent E TX. At the same time, the SW
to NE oriented area of -SHRA with -FZRA (where temps are at/below
freezing) remains progged to gradually shift SE across E TX into N
LA this evening, just as the freezing line oozes SSW to near a MNE
to RSN/MLU line as of 03Z. The HRRR suggests that the freezing
line will encompass much of Bienville, Jackson, and Nrn Caldwell
Parishes late this evening and overnight, as this area of precip
continues near and N of the H925 trough oriented from E TX into N
LA along the moist subtropical jet.
Given the fact that the freezing line has already encompassed
much of Union County and Nrn Columbia County, with the CAMs and
GFS in agreement with this axis of -FZRA persisting this evening
and overnight, have expanded the Winter Storm Warning for these
two counties in SW AR through 12 PM Wednesday, while also
expanding the Winter Weather Advisory through 12 pm Wednesday as
well for the existing Advisory area in addition to Bienville,
Jackson, and Caldwell Parishes. The development of an increasing
20-30kt Srly H850 flow atop the shallow cold dome will enhance
overrunning near and atop the H925 trough as it drifts back N
across E TX into Srn AR, such that -SHRA will become more
widespread across much of the region during the afternoon,
becoming more enhanced by large scale forcing ahead of the closed
low and it begins to open up and approach far W TX from Nrn Old MX
late Wednesday night into Thursday. The 12Z NAM 2M temp guidance
as well as the HRRR 2M temps suggest that the increased
overrunning will result in warming of the shallow cold lyr during
the afternoon Wednesday, such that temps should climb above
freezing (in the mid/upper 30s) over much of the area. However,
there is some indication that near freezing temps may linger
across our far Nrn CWA fringes in SW AR and SE OK, as the
precipitation builds back NE during the afternoon. Uncertainty
does exist though with the position of the freezing line during
the afternoon, with the vast majority of the guidance suggesting
all liquid through the afternoon over these areas. Thus, have held
off on extended the winter headlines through the afternoon, and
will be re-evaluated again by the mid shift tonight.
There is also some indication by the HRRR/NAM that the freezing
air may also try to backdoor SW back into SW AR Wednesday evening,
possibly nearing the LA border as the strong overrunning maintains
the widespread precipitation. Again, the vast majority of the
guidance envelope continues to suggest liquid elsewhere, but given
the uncertainty as to the placement of the freezing line in this
third period of the forecast, as well as the potential for
conflicting messages given that much of the area should climb
above freezing Wednesday, have held off on the extention/issuance
of the existing or new winter weather headlines and will allow for
the mid shift tonight or day shift Wednesday to re-evaluate. In
any case, giving this continually evolving forecast, please
continue to monitor that latest forecasts from our office.
The latest guidance also suggests that the progressing trough
across Texas is a bit slower than previous runs, with dry slotting
finally tapering the rains from W to E during the afternoon. Did
extend the existing Flood Watch through 00Z Friday to account for
the slower low progression and heavier rains, with additional
rainfall amounts of 1-3 inches expected.
Thank you WPC, and WFO`s JAN/LZK/FWD for coordination this
afternoon.
15
&&
.LONG TERM...
(Wednesday night through next Monday)
Issued at 326 PM CST Tue Jan 31 2023
As we kick off this long-term forecast on Thursday morning, heavy
rain will be ongoing across most of the region. This heavy rain will
be associated with the final push of vorticity associated with the
trough ejection. Between Wednesday night and Thursday AM, an
additional 1-2 inches of rainfall will be possible, with locally
heavier amounts certainly possible. As such, the flood watch will
appropriately remain in effect into Thursday evening. However, the
heavy rain should begin to taper off Thursday early afternoon, with
PoPs clearing the region by Thursday evening.
Behind the front and trough, temperatures to start the weekend
should begin with a seasonal feel. Highs Friday and Saturday will be
in the mid-50s, with overnight lows ranging the upper-20s to low-
30s. However, upper-level ridging will move overhead of the region
come Sunday, allowing for things to warm up into the new workweek.
Highs Sunday and into Monday will look something like Spring, with
highs in the low to upper-60s.
/44/
&&
.AVIATION...
(00Z TAFS)
Issued at 517 PM CST Tue Jan 31 2023
IFR/LIFR conditions will continue areawide overnight into
Wednesday. -RA conditions across TYR/GGG/SHV/ELD/TXK/MLU terminal
sites to become -FZRA by 01/03Z. Precipitation to transition back
to -RA by 01/18Z as temperatures warm above freezing. Otherwise,
NE winds 5-10kts to prevail areawide through the terminal forecast
period. /05/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 33 36 34 44 / 70 90 100 100
MLU 32 36 34 42 / 40 70 100 100
DEQ 28 34 31 47 / 30 90 100 60
TXK 31 35 32 46 / 60 100 100 80
ELD 29 34 31 42 / 70 80 100 90
TYR 30 34 33 44 / 60 100 100 80
GGG 33 36 34 44 / 70 90 100 90
LFK 35 39 36 46 / 30 80 100 90
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Winter Storm Warning until noon CST Wednesday for ARZ050-051-060-
061-072-073.
Flood Watch through Thursday afternoon for ARZ059>061-070>073.
Winter Weather Advisory until noon CST Wednesday for ARZ059-070-
071.
LA...Flood Watch through Thursday afternoon for LAZ001>006-010>014-
017>022.
Winter Weather Advisory until noon CST Wednesday for LAZ001>006-
012>014-021.
OK...Winter Storm Warning until noon CST Wednesday for OKZ077.
TX...Winter Storm Warning until noon CST Wednesday for TXZ096-108>111-
124-125-136.
Flood Watch through Thursday afternoon for TXZ097-109>112-
124>126-136>138-149>153-165>167.
Winter Weather Advisory until noon CST Wednesday for TXZ097-112-
126-137-138-149-150.
&&
$$
SHORT TERM...05
LONG TERM....44
AVIATION...05