Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/09/22
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
822 PM CST Tue Mar 8 2022
.UPDATE...
Issued at 821 PM CST Tue Mar 8 2022
Overall the forecast is on track so no major changes this evening.
&&
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 212 PM CST Tue Mar 8 2022
The primary forecast challenge is temperature.
At 2 PM CST, under a partly to mostly cloudy sky, temperatures are
maintaining in the 20s and 30s. Northwest winds of 20 to 35 mph with
gusts up to 45 mph in a few locations continue as well. What appear
to be some steep low-level-lapse-rate-supported returns working
southeast across the region on radar are persisting this afternoon,
too, despite the notable low level dry air advection that`s taking
place.
For the next 24 hours, low level CAA will happen on northwest winds
while surface high pressure shifts south and east over the region,
centering itself over the CWA by the end of the day Wednesday.
Wednesday night, the surface high re-locates further east and south
in the region, and a weak low level west-southwest component wind
develops. The airmass that northwest winds bring will be quite cold
for March (~2 standard deviations below normal at 850hpa). There may
be pockets of clearing overnight, which is believable, given the cu-
characteristics low level cloudiness has taken on today, and the
degree of previously mentioned low level dry air advection that will
continue to take place. That said, the RAP model is suggesting
nearly full overcast low stratus coverage, cwa-wide, through all of
tonight and the first half of Wednesday before wholesale clearing
takes place. This is the biggest question mark in the short term, as
skycover will play a role in how cold it could get tonight and how
warm it could get on Wednesday, despite there being a prevailing 10
to 20 mph wind tonight/Wednesday.
.LONG TERM...(Thursday through Tuesday)
Issued at 212 PM CST Tue Mar 8 2022
The long term begins on Thursday with an area of low pressure and
upper level trough tracking southeast across southern Canada into
Minnesota. The main impact with this system will be gusty
northwesterly winds Thursday night into Friday morning. Half km
winds reach 25 to 35 knots, with the strongest occurring over the
northeast portion of the CWA Friday morning. The airmass behind the
low pressure system is extremely cold, with 925 mb temps of -20C at
12Z Friday, with very little change throughout the day. Based on
sounding climatology, the -20C at 12Z Friday is near a record low of
minus 21.9C set in 2009 for that sounding time period. The high in
Aberdeen on March 11, 2009 was zero degrees, with a SD of 3 inches.
Limited snow pack this year should yield warmer temperatures, with
highs in the single digits, to the lower 20s across the CWA.
Warm air advection develops over western SD Friday night with
temperatures possibly warming toward Saturday morning. The WAA will
spread across the CWA on Saturday, with highs reaching the lower
30s, in western MN, to the mid 50s, in central SD. An approaching
cold front Sunday afternoon should bring slightly cooler
temperatures, as well as the potential for light pcpn. As of now,
NBM suggests pcpn may impact the northeast corner of the CWA. After
a brief cool down on Monday, temperatures should surge warmer on
Tuesday due to a strong low pressure system crossing well north and
east of the region.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 513 PM CST Tue Mar 8 2022
Terminals KABR,KATY,KPIR,KMBG
A mix of VFR/MVFR cigs are expected overnight. Meanwhile, any snow
showers will dissipate early this evening. Snow showers could
promote brief periods of low vsby until they end.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TDK
SHORT TERM...Dorn
LONG TERM...SD
AVIATION...TDK
Area Forecast Discussion
National Weather Service Bismarck ND
911 PM CST Tue Mar 8 2022
.UPDATE...
Issued at 909 PM CST Tue Mar 8 2022
The Winter Weather Advisory has been allowed to expire. While
scattered snow showers continue to be observed across central and
eastern parts of the state, decreasing wind speeds have led to a
reduction in blowing snow and in turn, improving visibility. The
snow showers are lasting a bit longer into the evening than
originally expected, but RAP analysis and forecast soundings do
still show a mixed boundary layer, and water vapor imagery
depicts a low-amplitude wave crossing the state. This wave should
exit the area by midnight, effectively ending snow shower chances.
UPDATE Issued at 603 PM CST Tue Mar 8 2022
Scattered snow showers and areas of blowing snow continue to
reduce visibility across north central North Dakota. The Winter
Weather Advisory has been extended until 9 PM CST for north
central and northeast North Dakota. Conditions have improved
enough in the northwest to allow an on-time expiration there. The
Wind Advisory has also been allowed to expire on time. Most
locations are consistently reporting sustained speeds and gusts
below advisory criteria, and those that are still meeting those
thresholds are mostly contained within the extended Winter Weather
Advisory.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 326 PM CST Tue Mar 8 2022
Gusty northwest winds with falling and blowing snow is causing
visibility reductions this afternoon, generally north. Wind and
Winter Weather advisories are in effect until 6 PM CST.
Broad cyclonic flow persists over central and eastern Canada,
while a shortwave trough embedded in the northwest flow on the
western periphery of the rotation dropped into the Northern
Plains this afternoon. After a cold front had moved through this
morning, gusty northwest winds and snow showers were impacting
North Dakota, reducing visibility under isolated to scattered
showers across the state and with blowing snow over areas of the
north.
The pressure gradient associated with the aforementioned shortwave
will gradually relax this evening, decreasing winds. Weak cold air
advection may maintain a northwest breeze, but otherwise the
blowing snow and winds should drop below advisory criteria early
this evening.
Expect cold temperatures tonight with morning lows from around -5
F to 5 F. Highs on Wednesday will remain chilly for the time of
year, ranging from around 5 above north to the mid teens south.
Though a less defined shortwave is expected to pass through
tomorrow, it should still be sufficient to drive scattered diurnal
snow showers in the afternoon.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 326 PM CST Tue Mar 8 2022
Very cold wind chills Thursday and Friday mornings will be the
highlight of the long term period.
With the previous shortwave pushing east early Thursday morning,
the cold surface high should be into the eastern Dakotas. Wind
chills down to around -30 F will be possible over the north and
east. Temperatures briefly rebound Thursday with highs in the
teens to mid 20s, before another cold front pushes through
Thursday evening and overnight. A blend of guidance keeps this
front dry for now, but can`t rule out some light snow along the
front with little to no accumulations. Wind chills will again be
an issue Thursday night and Friday morning with the seasonably
cold low level air mass and unidirectional northwest flow
expected. Advisories will likely be needed both periods of
Thursday and Friday night/mornings.
Good agreement exists in height rises and ridging developing this
weekend and next week, which should brings daily temperatures
to and subsequently above normal. Slight precipitation chances
remain this weekend with a couple weak open shortwave troughs, but
notable QPF is unlikely.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 909 PM CST Tue Mar 8 2022
Scattered snow showers are expected to diminish later this
evening. A brief MVFR visibility reduction remains possible at
KBIS and KJMS. Ceilings will likely trend toward a prevailing MVFR
overnight. VFR conditions may emerge Wednesday morning before MVFR
ceilings redevelop for Wednesday afternoon, when another round of
scattered snow showers is likely across western and central North
Dakota. Northwesterly winds will sustain around 10-20 kts through
the forecast period, becoming gusty at times.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Hollan
SHORT TERM...AE
LONG TERM...AE
AVIATION...Hollan
Area Forecast Discussion
National Weather Service Cleveland OH
921 PM EST Tue Mar 8 2022
.SYNOPSIS...
Low pressure will track across the central Appalachians late
tonight and Wednesday morning pulling a cold front across the
region by Wednesday afternoon. High pressure will return late
Wednesday through Thursday night. A cold front will cross the
region Friday, and this front will act as a focus for a strong
low pressure system lifting north from the Gulf Friday night
into Saturday.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
920 pm update...
No significant changes were made to the ongoing forecast
through tomorrow morning.
Previous discussion...
Satellite loops show that clouds are finally beginning to erode
over eastern Ohio and western PA, and this clearing line is
gradually working its way west of the I-77 and I-71 corridors
thanks to the stubborn low-level moisture finally scouring out.
This is due to 1016 mb surface high pressure centered over the
Upper Midwest sliding into the lower Great Lakes this evening.
Clouds held temps in the upper 30s this afternoon, so despite
some sun to close out the day, a chilly evening is on tap.
Attention tonight turns to a southern stream system that will
brush our southern and eastern counties with light snow changing
to rain late tonight and Wednesday morning. The mid/upper trough
is currently crossing the lower Mississippi Valley with
deterministic and HREF guidance in agreement on this shortwave
lifting through the Ohio Valley late tonight and Wednesday
morning with the surface low tracking across the Tennessee
Valley and central Appalachians while gradually deepening
beneath the right entrance region of a 135-150 knot H3 jet.
Moisture advection and isentropic ascent atop a mid-level
baroclinic zone/frontal boundary laying SW to NE across the
Ohio Valley will lead to a shield of light snow moving across a
roughly Stark and Mahoning to Crawford County line in the 10-14Z
timeframe. HREF guidance generally paints the QPF axis in this
area, but some slight northwestward trend was noted, so
increased PoPs to likely/categorical in these areas with chance
PoPs as far NW as Lorain County and points ENE into Erie County
PA. NAM and RAP BUFKIT forecast soundings do show strong Omega
in the mid-levels aligned with the DGZ as expected from the
aforementioned mid-level isentropic ascent atop the 700-500 mb
front, but there is a lot of dry air beneath this layer before
13Z, and by the time the profile saturates better after 13Z,
surface temps are warming enough for a changeover to rain. This
will keep snow amounts very light. Lowered amounts from the
previous forecast with generally 0.5 inch or less from Stark and
Mahoning Counties through Crawford County PA. Light rain will
then continue from mid morning through early afternoon generally
east of I-77 as temps warm, but all precip will end from west to
east after 17 or 18Z as the system and upper support exit across
the Mid-Atlantic. A large area of surface high pressure
building SE from the Upper Midwest late Wednesday and Wednesday
night will then maintain dry conditions the rest of the day
through the overnight.
Highs Wednesday will actually be warmer than today as we get
some sunshine by mid to late afternoon thanks to the high
building in. Generally mid 40`s expected. Clearer skies and
light winds the first half of Wednesday night will allow lows to
fall into the mid/upper 20s.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Winter will return for a brief period as another storm system
makes an approach toward the forecast area by the end of the
week. An upper level trough will dive southeast through central
Canada Thursday and Friday and then extend southwest into Texas.
Surface low pressure is progged to develop over the Gulf of
Mexico and pieces of energy will be ejected northeast along a
cold front. The front is expected to become nearly stationary
Friday night. Moisture will move east into the area along the
cold front and become nearly stationary with the stationary
front over the local area. As surface low develops over the Gulf
Coast, a surge of moisture will move northeast with the surface
low. Positive vorticity advection ahead of the upper level
trough will initiate the first round of precipitation starting
Friday in the form of mostly rain. Then, as cold air advection
pushes deeper into the forecast area, the rain will change over
to all snow Friday night. This system appears it will move
northeast toward the area fairly quickly and actually exit the
area Saturday. As of right now, snow accumulations across the
southeast half of the forecast area will range between 3 and 5
inches. As always, if this system slows down in forward motion,
snow accumulations will likely increase. Snowbelt areas in the
northeast will see higher amounts as the synoptic snow
transitions to lake effect. Latest model soundings support
extreme instability and laminar flow from about 290 to 300
degrees. Lake Erie is pretty much wide open and with the cold
temperatures expected, there is a potential for some good lake
effect snow. Will mention high chance POPs for now but see this
increasing as time goes on. Otherwise, areas to the west and
south will see snow gradually tapering off Saturday from west to
east during the transition to lake effect. Temperatures in the
40s should prevail Thursday and Friday but will plummet for
highs by Saturday only into the 20s. Lows Thursday night in the
20s and in the teens to lower 20s by Friday night.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
The upper level trough that is expected to bring a vigorous surface
low to the southeast of the forecast area will swing quickly east
through the area Saturday night. This will allow a broad upper level
ridge and resultant surface ridge to build east into the forecast
area for the latter half of the weekend. The surface high is
expected to be centered over the southeastern states by Sunday
night. Surface low should track east through central Canada and
weaken. Meanwhile, a warm front should lift northeast across the
local area by Sunday night. Temperatures should begin to rebound
nicely early next week as southwest flow returns to the area. A low
pressure system will move east into the western Great Lakes and then
move northeast forcing a cold front east across the local area
Monday into Monday night. This system will bring a round of showers
to the area. Surface ridge builds east over the area by Tuesday with
yet another warmup to follow. Temperatures in the teens Saturday
night should recover to the lower 30s east to lower and middle 40s
central and west respectively Sunday. Highs by Monday will top out
in the 50s in the warm air advection followed by slightly cooler
temperatures in the middle 40s east to lower and middle 50s
elsewhere by Tuesday. Lows by Tuesday morning in the 30s.
&&
.AVIATION /00Z Wednesday THROUGH Sunday/...
VFR conditions will continue this evening into most of the
overnight. A weather system will skirt by south of the area by
Wednesday morning. MVFR ceilings and drop in visibilities will
be possible for MFD, CAK, AND YNG roughly between 12z and 18z
Wednesday morning. Also, have PROB30 groups for CLE and ERI
roughly between 12z to 17z for this potential of light rain or
snow and/or mix bringing down visibility to 5sm and ceilings to
2500 to 3000 feet. Conditions will improve back to VFR after 18z for
these TAF sites that have the potential in the morning for MVFR
and light rain/snow. Winds will be fairly light and variable
this evening and overnight. Winds will generally become westerly
5 to 8 knots later Wednesday morning through the afternoon.
Outlook...
Non-VFR conditions are possible wit widespread rain Friday
before changing over to all snow Friday night into Saturday.
&&
.MARINE...
Lake will be relatively quiet through Friday. Winds will be
increasing by Friday night into Saturday as a strong storm system
moves quickly northeast along the Appalachian Mountains. This
system will result in waves building across the lake; especially as
flow becomes more northwesterly across the area. Some diminishing of
the winds will take place by Sunday. Anticipating a small craft
advisory will likely be needed by Friday night into Saturday night.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Garuckas
NEAR TERM...Garuckas/Griffin
SHORT TERM...Lombardy
LONG TERM...Lombardy
AVIATION...Griffin
MARINE...Lombardy
Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
935 PM EST Tue Mar 8 2022
...Evening Update...
Have updated near-term temperatures and dew points as scattered
to widespread rainfall during the late afternoon and early evening
hindered warming and left temperatures a few degrees lower than
forecast heading into tonight. Used CONSShort (a RAP + HRRR + LAMP
blend) for T and Td through 06z. Isolated to scattered showers
will continue overnight mainly along and north of the I-20
corridor. At the time of this writing, the chance for thunder is
decreasing as instability decreases.
Previous discussions follow...
Martin
&&
.SOGGY CONDITIONS PERSIST INTO EARLY WEEKEND...
SHORT TERM /Tonight through Wednesday Night/...
Broad isentropic lift with some convective elements has rain,
moderate to heavy at times, filling in across all of north GA and
portions of central GA this afternoon ahead of a weak shortwave
embedded within SW upper level flow over the region. Broad trough
to the west will remain mostly in place through the forecast
period, though another more vigorous shortwave will lift through
the area tonight into tomorrow morning. This will allow for
previously stalled cold front to the south of the area to begin to
lift into central GA before another surge of cooler air pushes
through tomorrow morning into the afternoon before stalling across
central GA.
Storms this afternoon have been relatively tame thus far, with
only one or two cores popping well above -20C, and even these
haven`t provided anything more than a few rumbles of thunder, as
surface air mass remains quite stable and elevated instability
marginal at best, with only 100-200 J/kg MUCAPE analyzed by SPC
SfcOA as of 19Z. Not expecting much in the way of severe as a
result through the afternoon into the evening. Going into tomorrow
morning and afternoon, as front surges into the area will likely
have ongoing convection along it. As sun comes up, airmass ahead
of this in parts of east central GA will destabilized and should
allow some of this convection to become sfc based, with HREF
showing sfc based CAPE values surging from 500-1000+ J/kg. Shear
profiles are not the most impressive, but sfc values of SRH are in
the 100-150 m2/s2 range, mostly concentrated in the low-levels,
which can certainly get the job done. Shear profiles in the 3-6 km
range get a little messy, as shown by hodo looped a bit over
itself, and given broad nature of forcing within right entrance
region of upper level jet streak and mechanical lift of cold
front, storm mode may be a bit messy overall, which should act to
limit overall potential. Still, can`t rule out a transient
supercell or bowing segment across far east central Georgia during
the afternoon hours, bringing with it a small tornado chance and
isolated hail/wind threat. Behind the front, expect to get a bit
of a break in the rainfall, but it will be short-lived, and areas
of central GA where the front stalls may not see much of a break
at all.
Last threat is the rain which will continue in north Georgia
through at least tomorrow morning. This will give widespread 1-2"
of rain with isolated higher amounts up to 3". Thankfully, soils
and rivers were in great shape before this, and spring bloom is
quickly ticking up, so not expected any widespread flooding
issues. Still, could see some of the usual problem areas
experience some flooding, especially where rainfall is heaviest,
so an isolated flash flood threat will exist through the morning
hours across north GA.
LUSK
LONG TERM /Thursday through Tuesday/...
Initial extended periods remain wet, with chilly, dry conditions
returning this weekend.
Cold front stalled near the southern CWA border will focus storm
development Thursday. Moist, modestly unstable environment and
deep-layer bulk shear of 50-60kts could produce some organized
storms, but weak low-level shear and limited large-scale ascent
could work in our favor to inhibit better severe storm coverage.
Even so, expect isolated strong to severe storms capable of
producing damaging winds and locally heavy rainfall. A tornado
cannot be ruled out. SPC currently has the southeastern portions
of the area outlooked for a Slight Risk, generally from Americus
to Louisville.
Rainfall totals for the 48-hour period ending Thursday night is
generally 1 to 2 inches over north Georgia (north of the metro
area), and 0.75 to 1.5 inches stretching from the Atlanta metro to
the southern CWA boundary. At this time the risk of flooding
still appears limited, though far north Georgia may see some
isolated low-lying issues.
Another surface low will develop over the northern Gulf and
southern Mississippi River Valley Thursday night, drawing moisture
back into central Georgia again through early Friday as yet
another `wave` of precipitation, though QPF amounts with the
overnight system are somewhat limited.
After a bit of a reprieve Thursday night and Friday, a
progressive longwave trough over the Great Plains will rapidly
intensify as it swings into the area on Friday. The associated
surface low will deepen as it lifts northeastward through the
state Friday afternoon and Friday night ahead of the front. Models
continue to favor the slightly slower timing of the frontal
passage, holding on to PoPs through Saturday morning then
clearing.
Strong northwesterly flow will accompany the frontal passage,
with a significantly dry air mass settling over the area through
the weekend. Wrap around moisture over north Georgia is expected
to overrun the cold airmass, producing light snow over far north
Georgia early Saturday. At this time, snowfall amounts are limited
to 0.5 inches or less, mainly in the higher elevations of north
Georgia. However, these amounts are highly dependent on lingering
moisture availability, and these amounts could change.
Though near-freezing temperatures are possible over north/west
Georgia Saturday morning, the coldest of the temperatures are
expected Saturday night into Sunday morning with the airmass
solidly in place. Temperatures are expected to drop into the 20s
and low 30s, and though dewpoints (winds) may be dry (high) enough
to prevent frost development, a hard freeze is looking likely for
much of the area. Temperatures will gradually increase underneath
strong surface high pressure Sunday and Monday, with possible
additional rain returning to the area Tuesday.
31
&&
AVIATION...
00Z Update...
A messy area of -RA with embedded -TSRA is spreading across north
GA with isolated showers developing across central GA. Cigs have
fallen to MVFR to IFR generally along and north of I-85, and will
stick around through the overnight hours. Maintained the PROB30
for LIFR cigs and -TSRA after ~09z at ATL and other metro sites
and after ~11z at AHN. MVFR to IFR vsbys are expected overnight,
as well. Aforementioned -RA/-TSRA will taper off ~06z with another
round expected Wednesday morning around 10z-14z for metro
Atlanta. Have VCSH at MCN and CSG overnight with cigs lowering to
IFR at 10z and 07z, respectively. Also possible to see brief
periods of LIFR cigs at these two sites. At all sites, winds will
be on the east side overnight, shifting to SW ahead of the line of
-SHRA/-TSRA Wednesday morning and then to NW behind the line.
//ATL Confidence...00Z Update...
Medium confidence on cigs and vsbys.
High confidence on all other elements.
Martin
&&
.PRELIMINARY POINT TEMPS/POPS...
Athens 51 67 48 57 / 90 90 40 40
Atlanta 49 61 48 61 / 90 90 40 30
Blairsville 47 57 41 58 / 90 70 20 20
Cartersville 47 60 42 62 / 90 60 20 20
Columbus 55 68 51 70 / 60 80 70 40
Gainesville 49 64 47 57 / 90 90 30 30
Macon 58 72 52 68 / 40 90 80 60
Rome 46 62 41 66 / 100 40 20 10
Peachtree City 48 63 47 63 / 80 80 40 40
Vidalia 65 76 59 70 / 50 90 100 90
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Martin
LONG TERM....31
AVIATION...Martin
Area Forecast Discussion
National Weather Service Grand Forks ND
953 PM CST Tue Mar 8 2022
.UPDATE...
Issued at 944 PM CST Tue Mar 8 2022
Most of the area has diminishing winds, so blowing snow visibility
issues have improved over the last few hours. As such, the Winter
Weather Advisory was allowed to expire at 9 PM. The primary
concern over the next few hours is the band of snow along a
convergent boundary in the Red River Valley. It is unclear how low
visibility is getting along this band as there is a low spatial
resolution of visibility observations in this area. Regardless,
given it`s track down I-29 and combined with the blow ice issues
from today, we`ve decided to push out an SPS for it. Will continue
to monitor over the next few hours for further issues.
UPDATE Issued at 636 PM CST Tue Mar 8 2022
Surface analysis indicates a subtle convergence boundary
stretching from western Cavalier County down through eastern
Norman County, indicated by a wind shift across the boundary.
Along this boundary, multiple bands of snow have developed,
causing visibility to fall as low as 1/2SM.
Winds ahead and behind the boundary are still gusting at 20-30
mph, so blowing snow remains a possibility. The primary concern
with these bands has been the whiteout conditions that have been
reported along it, especially along Highway 2. As instability
begins to wane tonight, we should start to see improvement in
visibility across the area, although blowing snow issues may still
persist at times. For now, we have decided to extend the Winter
Weather Advisory through 9 PM due to ongoing reports and
persistent horizontal convective rolls.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 239 PM CST Tue Mar 8 2022
A clipper system continues to provide winter weather impacts from
gusty winds, falling snow, and blowing snow across the FA. Main cold
front has pushed out of the FA leaving gusty winds out of the west-
northwest in its wake. This is leading to a decent push of CAA as
seen by upstream obs in northwestern North Dakota. Winds are
primarily being driven by pressure gradient and mixing this
afternoon. RAP soundings continue to indicate deep mixing up to 850
hPa working to bring stronger winds to the surface, although 850 hPa
winds do look to diminish as the day wears on as well. Elsewhere in
the CWA, these gusty winds continue to provide blowing snow impacts
across the Devils Lake basin. Obs are generally down to a mile or
less at times in counties downstream of the Turtle Mountains.
Otherwise, snow showers are also beginning to crop up in the
northern valley. This, in conjunction with the gusty winds are
leading to areas of reduced visibilities down to a mile or less at
times as well. These areas of blowing snow will continue to provide
winter weather impacts into the evening hours, when winds are
expected to diminish. Despite this, falling snow may continue to
exist tonight as CAA snow showers will likely persist.
Moving into Wednesday, a cooler day is in store as CAA persists.
Winds will be lesser, but still a bit breezy throughout the day.
Highs generally in the single digits to low teens are expected as a
result. Current CAM guidance continues to indicate the possibility
for spotty snow showers driven by CAA as a shortwave progresses to
our southwest. The presence of drier air and lack of synoptic
support, however, generally keeps thinking that any snow shower
activity will likely be minimal. Despite diurnal trends, CAA will
work against us then as low temperatures Wednesday night into
Thursday morning look to drop into the negative single digits to
negative teens. With winds remaining in the 5-10 kt range, wind
chill values look to drop into the advisory level once again with
forecast apparent temperatures in the -20s to -30s.
.LONG TERM...(Thursday through Tuesday)
Issued at 239 PM CST Tue Mar 8 2022
Impacts across the Thursday through Tuesday period are expected to
be minimal, with very cold temperatures and wind chill values being
our primary concern. Arctic air advects into the area following
several clipper systems that traverse the region over the coming
week. The cold temperatures will combine with north to northwest
winds to bring wind chills down to near 30 below zero, especially
Friday night into Saturday morning. Very light snow is possible as
these systems move quickly through the area, with our best chance
expected to occur Saturday into Sunday.
The upper air pattern remains northwesterly through the extended
period, with very good agreement between probabalistic sources to
include the GEFS and ECMWF suites. The upper ridge to our west
continues to influence the flow of cold air, allowing shortwaves to
traverse the H5 flow and reinforce our cooler than average
temperatures. Warmer temperatures are expected to return, at least
briefly, heading into the late weekend and early next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 733 PM CST Tue Mar 8 2022
Widespread MVFR cigs are expected to prevail over the next few
hours, with a few spots crossing into IFR thanks to falling snow.
Expect conditions to gradually improve in terms of visibility over
the next 2-3 hours.
Winds will still persist tonight through at least 06z before
beginning to finally diminish. Isolated areas of BLSN and -SN
could cause intermittent category issues, although these aren`t
expected to be predominant after 06z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...Perroux
SHORT TERM...Rick
LONG TERM...Lynch
AVIATION...Perroux
Area Forecast Discussion
National Weather Service Indianapolis IN
1006 PM EST Tue Mar 8 2022
.Forecast Update...
Issued at 1006 PM EST Tue Mar 8 2022
Radar was showing some light returns that were not reaching the
ground. While, there is little in the way of forcing 290-295K
Isentropic analysis was showing some lift over south central
sections centered in between about 06z-09z or so. With saturation
implied by low pressure condensation deficits, there is a brief
window of precipitation. The question then becomes, precip type and
the HRRR and surface temperatures and dew points support a rain to
snow mix. Slight chance and chance PoPs still look like the way to
go with little to no snow accumulation expected. Made some changes
to temperatures as Crawfordsville is once again several degrees
colder and drier than the other ob sites.
&&
.Short Term...(This evening through Wednesday night)
Issued at 315 PM EST Tue Mar 8 2022
Elongated surface high pressure continues over the area throughout
the short term period. As of this afternoon, the high is centered
directly over central Indiana and will continue to progress ENE,
leading to dry weather.
Model soundings show moisture aloft keeping clouds over the area
into at least early tomorrow morning despite the dry weather and
subsidence at the surface. From satellite, can see that today`s
stubborn clouds are finally starting to thin out as of mid-
afternoon, but also shows more mid and high level clouds moving in
from the SW due to isentropic flow north of a surface low pushing
through the Tennessee Valley. This low will also bring a chance
of precipitation in the far southern portion of the forecast area
for the early Wednesday morning hours. The high in place should
help to keep most precip to the south of the area, but depending
on how the low tracks, may not keep out all the precip. With lows
in that area tonight in the mid to upper 30s, p-type should stay
rain but can`t rule out some snow mixing in as well. Any
accumulations should be minimal.
Upper SW flow will persist through the period, leading to near
normal temperatures. Tonight`s low will be in the low to mid 30s
followed by highs tomorrow near 50.
&&
.Long Term...(Thursday through Tuesday)
Issued at 315 PM EST Tue Mar 8 2022
Modest warm advection and absence of ridging will keep us from
warming substantially prior to the arrival of the next trough. So,
we should see near normal temperatures for early-mid March on
Thursday.
By Friday, phasing of northern and southern stream waves will lead
to a deepening/amplifying trough over our area. Strongest forcing
will be east of us into Friday night and Saturday, interacting with
a plume of deeper moisture east of our area. Thus, probabilities for
precipitation are not across our area. We have trended the forecast
colder than blended guidance based on model trends of quicker cold
advection. This won`t be a scenario with a strong warm nose to
complicate precipitation type and so thermal profiles in model
soundings quickly support snow as cold advection strengthens
throughout the day.
Most deterministic and ensemble guidance has around 0.25" QPF for
the southeast tapering to around 0.10" or less in the northwest,
most of which will occur after thermal profiles become supportive of
snow. This could yield accumulations up to around an inch of snow
across the area, though details with trough deepening, amplitude,
and phasing could alter this. So, there remains some uncertainty.
Strong cold advection Saturday will hold temperatures in the low-mid
20s in most area. Strong warm advection begins Sunday given the
progressive synoptic-scale pattern. This will drive temperatures
quickly back to near or above normal Sunday. Continued warming is
expected early next week. A low-end precipitation event may happen
late Monday into early Tuesday, but model spread is relatively high
at this time range so probabilities are low at this time. The
warmer pattern would support rain.
&&
.Aviation...(00Z TAF Issuance)
Issued at 629 PM EST Tue Mar 8 2022
IMPACTS:
- VFR flying conditions are expected through the TAF period. Small
chance for some MVFR ceilings through 04z. Otherwise, VFR flying
conditions are expected through the TAF period.
- Winds will be light to calm tonight and from 290 to 330 degrees
after 13z Wednesday less than 10 knots.
DISCUSSION:
High pressure will be over the terminals tonight. Then, a cold front
will drop southeast across the terminals Wednesday afternoon and
evening. This will result in a wind shift and slight increase in
northwest winds.
Model soundings suggest some MVFR stratus ceilings tonight, but current
trends are for this deck have scattered or less coverage.
Winds will be light to calm tonight and northwest less than 10 knots
Wednesday.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...MK
Short Term...KH
Long Term...BRB
Aviation...MK
Area Forecast Discussion
National Weather Service Lubbock TX
541 PM CST Tue Mar 8 2022
.AVIATION...
VFR will continue through the TAF period with increasing southerly winds
late Wednesday morning.
&&
.PREV DISCUSSION... /issued 207 PM CST Tue Mar 8 2022/
SHORT TERM...
The northern portion of an upper level trough axis is currently
centered over the Texas Panhandle and will continue to lift
northeast overnight. Temperatures today will remain 10-15 degrees
below normal despite mostly clear skies. Zonal flow aloft by early
Wednesday morning will quickly evolve into another broadening trough
across New Mexico and West Texas by early afternoon. Lee side
surface cyclogenesis over SE Colorado and the TX/OK Panhandle will
result in an increase and veering of surface winds from southeast
overnight to stronger southwest by late tomorrow morning into the
afternoon for locations on the Caprock and the southwest Texas
Panhandle. Fire Weather conditions are expected to become elevated
by tomorrow afternoon over the western South Plains and southwest
Texas Panhandle. Temperatures at or slightly lower than normal are
currently the limiting factor as fuels remain exceptionally dry
across our area. Overnight lows are also expected to be well below
normal tonight into early tomorrow, in the upper teens and 20s area
wide.
LONG TERM...
Large scale cyclonic curvature remains aloft late this week. The
next significant upper level impulse digging southeast out of
southwest Canada will move into the desert southwest Thursday
before swinging progressively across the southern high plains
early Friday. A cold front will precede this upper trough, diving
quickly southward. Latest trends have seemingly confirmed earlier
suspicions that the faster frontal passage solutions are favored,
and all current solutions have trended faster with this cold front.
We continue to favor the HRRR bringing the cold front through the
entire area by about 10Z Thursday morning, and if trends pan out
it could pass even earlier along with fairly stiff winds near 25
mph sustained. The airmass directly behind this cold front appears
to be rather cold, with the 900 millibar or near surface
temperatures dropping into the upper teens to lower 20s early
Thursday on the Caprock, and mostly 20s to lower 30s over the
Rolling Plains. Some indications of a low cloud layer persisting
southward into the area but solutions are not favoring this at the
present time. Still, we suspect there could be areas of low clouds
and possibly even patchy freezing drizzle early Thursday. We have
not indicated this in the current forecast rendition, but will
monitor trends. Thursday otherwise appears will be slightly colder
than previously indicated, again favoring the colder solutions.
As lift from the upper trough referenced above passes overhead
late Thursday night and early Friday, there still may be a chance
for light wintry precipitation. Most solutions remain very light
with expected precipitation totals which makes sense given the
open progressive upper trough passage. Snow accumulation
potential currently looks low, but we will retain the mention of
the wintry precipitation within the Hazardous Weather Outlook, as
well as a risk for low Wind Chills approaching minus 5 F across
the southwest Texas Panhandle by early Friday.
Cold and dry air will follow late Friday into early Saturday, but
upper heights will rebound Saturday with westerly flow Sunday, and
a solid warmup is expected with highs recovering back into the 60s
Saturday and 70s Sunday. Unknown for Monday will be the degree of
cooling behind another possible fast moving but weaker looking
cold front, then warming should take over by Tuesday of next
week. Another potent looking upper trough appears will be
approaching next Wednesday or Thursday. RmcQueen
FIRE WEATHER...
Elevated to marginally critical fire weather conditions are
expected to develop from late morning Wednesday through the
afternoon hours for the western South Plains and far southwestern
Texas Panhandle. An area of strong southwest surface winds (~20kt)
will expand east from New Mexico into our CWA by late morning. Along
with the strengthening surface winds, RH values are expected to drop
into the teens and fuels remaining critically dry. Temperatures at
or slightly below normal for this time of the year remain the
limiting factor attm. Have held off on issuing a Fire Weather Watch
at the moment.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
01
Area Forecast Discussion
National Weather Service Memphis TN
757 PM CST Tue Mar 8 2022
.UPDATE...
Widespread light to moderate rain continues across much of the
Mid-South this evening. Temperatures are currently near 40F in
most areas with dewpoint depressions now only a couple of degrees.
Evaporative cooling and strong forcing for ascent have been able
to quickly cool temperatures aloft, allowing for patchy sleet to
mix in with the rainfall this afternoon. We`re not seeing much of
that over the past hour or two with RAP point soundings indicating
a more saturated, isothermal column near 0F from the top of the
boundary layer through approximately 850 mb. Most of this
precipitation will fall as rain but with some additional cooling
aloft (and at the surface), a few snowflakes (or sleet pellets)
could mix in at times, mainly north of I-40. Fortunately, this
should result in no hazard concerns given the surface temperatures
well above freezing.
Impressive mid-level frontogenesis will continue to weaken
overnight within the main frontal band, causing precipitation to
gradually wane overnight. However, a secondary area of
frontogenesis near 700 mb in the deformation zone northwest of the
850 mb low coupled with ascent associated with the right entrance
region of a strong upper-level jet will allow for light rain to
persist across portions of west TN into the early morning hours.
Dry weather is anticipated tomorrow with temperatures warming into
the mid 50s.
MJ
&&
.PREV DISCUSSION... /issued 328 PM CST Tue Mar 8 2022/
DISCUSSION...
Currently...Rain is quickly spreading into the area as a mid level
trough pushes through the southern plains with lift and moisture
increasing across the Mid-South. Surface low pressure is
developing over the NW Gulf and will track NE across the SE US
tonight.
The associated rain shield will quickly spread over the region
this evening and then lift out after midnight. Some brief sleet is
possible upon onset due to dry air aloft. QPF amounts will be
heaviest toward north MS with some embedded convection resulting
in amounts perhaps up to 2 inches toward Monroe County. Some
localized flooding is possible. As the system pulls out would not
be surprised to see a wet snowflake along the KY border late. Some
clearing is possible across NE AR by morning. Lows will be mostly
in the 30s.
Wednesday and Thursday...A dry period between systems will prevail
with weak surface high pressure ridging. It might take a while to
clear out Wed and Wed night as low clouds may remain trapped
especially across north MS. Thursday looks like a pleasant day
with a good deal of sun and highs mainly in the 60s.
Friday and Saturday....A cold front will move through the region
on Friday with much colder air rushing into the region during the
day. Expect morning highs followed by falling temps. Areas across
NE MS will likely warm into the upper 60s. 12z models, to varying
extents, continue to advertise energy ejecting from the SW US
into the southern plains Friday and Friday night. In response to
the mid level trough pushing into the southern plains, low pressure
may develop across the north gulf coast and lift NE across the SE
US Friday night. Increasing lift and moisture assoicated with the
mid level trough pushing into the region may result in a
significant area of post frontal precipitation across the Mid-
South Friday afternoon into Friday evening. Precipitation will
start as rain and likely change to snow. It is still too early to
pinpoint amounts but some accumulations are possible. Precipitation
will lift out after midnight with temps dropping deep into the
20s by morning. Saturday will be downright cold with brisk NW
winds and highs in the 30s...colder if we have some snow on the
ground. Saturday night will be another cold one with lows in the
upper teens east.
Sunday through Tuesday...High pressure will shift SE and
southerly winds and milder temps return. A quick moving system
will bring a chance of rain mainly Monday night.
SJM
&&
.AVIATION...
/00Z TAFs/
Ongoing -RA will continue at all sites through the overnight
hours. Current VFR conds will rapidly deteriorate to IFR within
the next couple of hours and remain that way overnight as well.
Rain will move out by early morning, with improving conds from
west to east by early afternoon. Winds will remain northerly
through the period.
AC3
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
959 PM EST Tue Mar 8 2022
.SYNOPSIS...
A stalled frontal boundary to our south will lift north as a
warm front across the area late tonight into tomorrow morning,
followed by a cold front crossing the area later tomorrow and
low pressure passing off the coast Thursday. High pressure
briefly returns Friday before a very strong cold front impacts
the area Saturday. Building high pressure brings more settled
weather Sunday through early next week.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 955 PM Tue ...The quasi-stationary frontal boundary
stalled to the south of our area this evening, will begin to
lift slowly north overnight in response to a digging shortwave
which will spur cyclogenesis along the stalled boundary causing
it to lift northward into eastern NC late tonight. Strong low-
level WAA will provide sufficient lift for a fairly widespread
area of rain which has already begun to develop especially over
areas north of Highway 70. The best coverage of precipitation
will be over the west and north counties. Over eastern NC, the
bigger concern will be a small window for severe potential,
especially along the coast, as the warm front begins to lift
north early in the morning ushering in an unstable airmass over
the region. As MLCAPEs of 500+ J/kg overspread the coast, 0-1 km
helicity is forecast to sit between 100-200 m2/s2 in the same
region with effective shear around 40 kt immediately on the warm
side of the front. This will pose a highly conditional tornado
threat for storms that develop in the early morning hours,
especially after 11z. By far the biggest wrinkle in this
forecast would be whether developing convective activity
offshore robs the region of enough low-level moisture to support
storms, as the 18z HRRR suggests.
The low will lift along the Piedmont of NC tomorrow, placing
much of our area in the warm sector. Although a few passing
showers are possible, most hi-res guidance shows a lull in
precipitation for much of the day although low cloud cover will
hold strong. The more likely period for thunderstorms will be
late afternoon into evening as the cyclone`s associated cold
front crosses NC, forcing a broken line of showers and possible
thunderstorms. The pre-storm environment will could become
favorable for storms capable of producing gusty/strong winds
with bulk shear holding around 40 kt and MLCAPEs between
500-1000 J/kg provided some clearing occurs ahead of the line.
The tornado threat will be lower as the highest low-level
helicity associated with the warm front will be displaced to our
north.
Low temperatures for tonight will likely occur close to midnight
with ensuing WAA resulting in temperatures in the upper 40s to
mid 50s rising steadily to the mid 50s to around 60 by sunrise.
Highs Wednesday reach into the mid to potentially upper 70s
along and south of Highway 70, and 60s north.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
As of 350 PM Tue...The cold front will cross the FA overnight,
pushing showers and storms offshore with it although skies will
remain cloudy. This front will again stall offshore, with the
potential for isentropically-forced showers to cross the Crystal
Coast early Thurs morning. CAA behind the front will knock
temperatures down into the 40s for all but immediate coastal
areas.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 4 AM Tue...Forecast through the rest of the week coming
into better view as persistent deep layer moisture advection on
the downstream side of broad troughing over the central US keeps
an active pattern in place into the weekend. Strong high
pressure brings more settled weather Sunday through early next
week.
Thursday...The precip lull will be very short-lived, as another
shortwave Thursday will develop surface low pressure within the
front offshore, with favorable upper dynamics spreading the
precip shield from the offshore low back to eastern NC during
the day Thursday. Persistent surface CAA limits instability and
possibly provides an enhanced isentropic component to the
rainfall. Categorical POPs mainly limited to the coast Thursday,
with likely POPs spreading further inland and 0.25-0.5 in QPF
possible across the area. Persistent CAA keeps highs 10-15 deg
cooler than Wed.
Friday through Monday...Inland ridging dominates Friday, with mainly
dry relative seasonable conditions. A digging upper trough will
then develop strong lower pressure over the deep south Friday
night, with the low passing over the western Carolinas Saturday.
The gradient will tighten very quickly beginning early Saturday
morning in response to the deepening low, and strong/gusty SW
winds are expected Saturday morning possibly into the
afternoon. Severe weather will be possible Saturday given the
very strong low level shear and moisture advection that will
occur, with coastal flooding and other wind- related issues
possible as well.
The associated strong cold front will cross the area later
Saturday, with the stronger winds becoming NW abruptly behind
the front and strong CAA beginning. This will bring an end to
the active pattern, with drier and much cooler high pressure
filling in Sunday through early next week.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /through Wednesday/...
As of 605 PM Tues...High confidence in sub VFR conditions
developing late this evening and persisting through the day Wed
mainly in MVFR to IFR ceilings. VFR conditions prevail for
awhile early this evening with lowering clouds overspreading the
terminals by late this evening. This pattern should hold into
most of Wed even in the warm sector with the warm front north of
the area. Partial clearing could occur in the afternoon as
drier air works northeast ahead of a advancing cold front from
the west. A broken line of showers and possible thunderstorms
with gusty winds is likely along/ahead of the front late Wed
afternoon into early Wed evening.
LONG TERM /Thursday through Sunday/...
As of 4 AM Tue...Continued flight restrictions possible
Thursday as low pressure passes offshore. VFR prevails Friday,
but might be shore-lived as a strong low and cold front will
bring strong SW winds and storms Saturday. VFR returns Saturday
night, though gusty NW winds could continue into Sunday.
&&
.MARINE...
SHORT TERM /Tonight through Wednesday/...
As of 955 PM Tues...Have issued a SCA for the Pamlico Sound for
low end advisory conditions Wed into Thu. Quick changing and
hazardous boating conditions are over the next 24-36 hours with
persistent SCA conditions across the coastal waters, and the
potential for short-lived conditions over inland waters Wed
night.
Stalled frontal boundary over a hundred miles offshore this
afternoon is expected to lift northward overnight as low
pressure developing over the Gulf states tonight lifts across
the Piedmont of NC. Easterly winds this afternoon will veer
southwesterly and increase to 15-25 kt in tandem with
strengthening LLJ aloft, building seas to 6-8 ft for southern
and central waters. Late Wednesday, the low`s associated cold
front will cross the waters resulting in a quick change to
northerly winds across the waters with a surge of SCA force
gusts likely. For soundside waters, relatively cool water
temperatures could put a damper on SCA conditions but guidance
was in good agreement that winds will reach 20-25 kt across the
eastern Pamlico Sound especially in the CAA behind the cold
front Wed night into early Thu.
For coastal waters, SCAs have been extended out into Thursday
given expected conditions as well as persistent N to NW flow
behind the cold front.
LONG TERM /Thursday through Sunday/...
As of 4 AM Tue...Moderate N to NW winds develop behind the cold
front, persisting Thursday and Friday. Quickly deepening low
pressure inland will bring strong SW winds beginning late
Friday/early Saturday, with solid gale force winds to maybe low
end storm force winds possible ahead of a very strong cold front
that will cross the waters during the day. Gusty NW winds
develop behind the front Saturday night into Sunday.
Seas mainly linger 3-6 ft through Friday, but increase very
quickly Friday night in response to strong winds developing.
Seas peak near 8-12 ft in southerly windswell Saturday
afternoon before gradually subsiding through the rest of the
weekend as wind direction shifts offshore.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 8 AM Wednesday to 10 AM EST Thursday
for AMZ135.
Small Craft Advisory until 4 AM EST Friday for AMZ152-154.
Small Craft Advisory until 1 PM EST Thursday for AMZ156-158.
Small Craft Advisory until 10 AM EST Thursday for AMZ150.
&&
$$
SYNOPSIS...MHX
NEAR TERM...JME/MS
SHORT TERM...MS
LONG TERM...CB
AVIATION...JME/CB/MS
MARINE...JME/CB/MS
Area Forecast Discussion
National Weather Service Pueblo CO
315 PM MST Tue Mar 8 2022
.SHORT TERM...(This evening through Wednesday)
Issued at 257 PM MST Tue Mar 8 2022
...Winter returns, again, starting Tonight...
Key messages:
1) Snow develops over the central mountains after midnight, becoming
steadier/heavier toward sunrise.
2) Snowfall spreads south and east across the mountains during the
day on Wednesday, and some pockets of heavy snow look likely along
the Continental Divide.
3)Strong cold front moves south through the plains by mid-afternoon
Wednesday, with falling temps, thickening clouds and increasing
snowfall chances following the frontal passage.
Strong March sun melting a good deal of snow today, as high
temperatures have pushed above freezing at many locations. High
clouds ahead of the next weather system already edging into nrn CO
this afternoon, and expect a general increase in mid/high level
cloudiness across the area overnight and through the day Wednesday.
Weak dynamic/orographic lift reach the central mountains overnight,
with snow breaking out from Monarch Pass northward after midnight.
Snow spreads across the remainder of the Continental Divide Wed
morning, then reaches the eastern mountains in the afternoon, as
upper jet dives into the Great Basin. Current set of advisories
handle mountain precip trends well, though did add Wet Mountain
Valley to the highlight as at least valley edges will see
significant snowfall. Along I-25 and over the plains, models
continue to speed up the passage of the cold front, with boundary
now reaching the Arkansas River by late morning, and the NM border
by mid-afternoon. Continued to nudge max temps downward as a result,
with steady or falling temps many locations east of the mountains
through the afternoon. Expect at least light snow to start on the
Palmer Divide in the afternoon as cold air deepens, while NAM/HRRR
have suggested for the past couple runs that enhanced snow band
develops over Pueblo County by 00z, as pronounced area of isentropic
upglide develops. Have issued a new winter weather advisory for
Pueblo/ern Fremont/Huerfano Counties to account for this potential,
though confidence is moderate at best in the exact placement of the
heavier band. Have left Teller/El Paso County out of any highlights
at this point, as many model solutions show a relative minimum in
snowfall initially over the these areas, and will let evening shift
take a look at the 00z runs before committing to a highlight here.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 257 PM MST Tue Mar 8 2022
Key messages:
1) The next major low pressure system will be transitioning over the
region from Wednesday night and through early Friday morning, with
more snow and much colder temperatures, and breezy conditions for
Thursday night which could result in dangerous wind chill values for
some locations.
2) Ridging will temporarily build in for the weekend with much more
mild temperatures, which will be right around the seasonal average
or even slightly above for most locations by Sunday.
3) A weaker trough will skirt across the region Sunday night through
Monday and may provide a chance of snow over the higher elevations
and a slight cooldown.
4) A well amplified ridge looks to build back in by the middle of
next week with much warmer and drier conditions expected.
Detailed discussion:
Wednesday night through Friday morning...
A longwave trough with a positively tilted axis is going to deepen
from the north over the region. An associated major shortwave with
this will begin to move over the area. A surface low pressure center
will develop along the cold frontal boundary and undergo
cyclogenesis right around the Oklahoma panhandle (models differ
slightly on the exact position and timing of this occurring but in
the general location and around 03Z/8 PM MST) as the positively
tilted upper level trough at the 500 mb level advances over the
colder airmass. Position of the trough axis does differ a little
between the latest model data. The ECMWF does not have propagation
quite as quick as the Canadian and GFS, and the GFS has the axis, as
well as the position of the closed low at the 500mb level slightly
ahead of all other models. The slower propagation of the ECMWF could
have snow showers lingering into the early morning hours over the
southern mountains if this model verifies.
Winds look to increase out of the NE`ly direction after the cold
frontal passage that looks to move over the southern plains roughly
around 00Z on Thursday (5 PM MST) according to the HRRR, maybe
slightly sooner with what the NAM 4km Nest is displaying. With the
mid level flow being primarily out of the west from the 700-500mb
level, with the colder airmass and NE`y wind component at the
surface and winds out of the ESE at the 850mb level, there looks to
be a fair amount of overrunning in the deformation zone, which will
result in some areas of the plains getting some good snow banding
initiating by late Wednesday evening and throughout the early
morning hours on Thursday. The NAM shows a concentrated area over
the Lower Arkansas River Valley as the colder air settles with an
easterly wind component adding to some upsloping. The HRRR is also
showing a similar display, especially over the southern portion of
the Lower ARV. Since snow banding can be unpredictable of where it
will initiate, snow amounts could vary quite a bit over the plains,
with most of the uncertainty being along the I-25 corridor. Over the
mountains, the greatest snowfall amounts look to be over the
southern mountains, due to the orientation of the trough and
position of the surface low. As the low continues to move eastward,
s now showers will continue to taper off later in the morning on
Thursday over the plains, but snow show showers could still linger
over the mountains going into the early morning on Friday. The
downsloping winds will provide somewhat of a rain-shadow effect for
the San Luis Valley, so snowfall totals should be generally less for
locations over the central part of the valley, such as Alamosa.
Temperatures and winds have been slightly with a blend of
CONSMOS for the winds and BCONSALL for the temps, due to the fact
that winds look to be stronger over the plains with significant cold
air advection and mostly cloudy skies, which will not allow temps to
achieve the max of what the NBM is displaying. Winds will continue
to weaken and return to a NW`ly flow over the plains most of the
plains during the day on Thursday. Winds will then begin to increase
as the pressure gradient tightens with the strengthening low on the
backside over the eastern plains during the night on Thursday, with
strong cold air advection in place. Due to this, dangerous wind
chill values could be possible and an advisory might be necessary.
Temperatures will drop off quickly over the plains throughout the
night on Wednesday and highs on Thursday will only make it to the
upper teens and low to mid 20s for most locations over the plains.
It will be warmer for the San Luis Valley due to this being a
shallow polar air mass and not penetrating the eastern mountains,
with highs around the low to mid 30s. Highs over the mountains will
generally be in the teens and 20s for most locations, with the
highest peaks in the single digits and around -5F to 0F for the
fourteeners. On Thursday night, lows will dip down into the single
digits for most of the plains, and possibly below 0F for the Palmer
Divide area. Temps for all of high country, including the valleys,
will likely be below 0 for most locations, and even as low as -15F
for the fourteeners. Wind chill criteria might also be met for the
Sangre de Cristo Mountains, as apparent temperatures could be down
below -30 for a few hours during the night at locations like Mount
Blanca, and thus might be necessary for this area as well.
Friday afternoon through Sunday...
High pressure is going to subsequently build in on Friday and
ridging is going to build slightly over the region throughout the
early part of the weekend but then begin to break down going into
the evening on Sunday. Temperatures will still be cool with the
polar airmass in place on Friday. The ridging and NW`ly downsloping
wind component will allow for temperatures to return to being much
closer to the seasonal average for this time of year on Saturday. It
is going to even further warm into Sunday, and some locations over
the plains will be above the seasonal average, with close to 70F for
the far southeastern plains and Lower Arkansas River Valley.
Sunday night through Tuesday...
Deterministic models differ slightly but all tend to agree that
there will be a weak upper level perturbation in the breakdown of
the ridge that passes over the region by late Sunday evening and
going into Monday. This will allow for a slight cooldown and some
snow showers to be possible over the higher terrain, otherwise
nothing more significant expect with this feature at this time as
models are still too far out to be considered reliable. Models do
also agree with a strong ridge building back in on Tuesday and
temperatures becoming much warmer again by the middle of next week.
-Stewey
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 257 PM MST Tue Mar 8 2022
VFR at all taf sites the next 18 hrs, with gradually increasing and
lowering VFR cigs tonight and Wed. Cold front will reach KCOS and
KPUB Wed morning, with north winds gusting to at least 25 kts after
16z-17z. Cigs lower to MVFR at KCOS and KPUB after 21z Wed, with
snow showers developing both terminals by 00z. Expect IFR conditions
at both sites from 00z into Thu.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 PM this evening to 5 PM MST
Thursday for COZ058>061.
Winter Weather Advisory from 11 AM Wednesday to 5 AM MST Friday
for COZ072>075-078>080.
Winter Weather Advisory from 5 AM Wednesday to 11 PM MST
Thursday for COZ066-068.
Winter Weather Advisory from 2 PM Wednesday to 5 AM MST Friday
for COZ083-086-087.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...STEWARD
AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Blacksburg VA
630 PM EST Tue Mar 8 2022
.SYNOPSIS...
Low pressure will develop along a stalled front over the
northern Gulf of Mexico tonight then track across the southern
Appalachians to the Mid Atlantic coast by Wednesday morning.
This will bring widespread rain across West Virginia, Virginia
and North Carolina tonight and Wednesday. The next large system
arrives on Friday night and Saturday with precipitation along a
strong cold front and colder temperatures Saturday and Sunday.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 620 PM EST Tuesday...
Getting better isentropic lift/moisture transport moving into
the western Carolinas and developing rain as far north as
Watauga-Yadkin County NC as of 620pm.
Rain will continue to spread northward this evening. At the
moment the forecast is on track. Do not see any hydro issues
outside of typical ponding of water on roads in moderate to
higher rainfall rates.
Previous discussion from earlier this afternoon...
Rain approaching northern North Carolina around 7PM.
Synoptic flow keeps long wave trough over the center of the United
States with broad southwest flow over the Mid Atlantic region and
Carolinas. At the surface, low pressure over eastern Texas tracks
into the southern Appalachians by Wednesday morning then the low
transitions east and deepens offshore by Wednesday afternoon. In-
situ wedging will be in place early Wednesday but as winds turn to
the west the wedge will erode.
850MB winds become southeast this evening with the highest wind
speeds and best upslope enhancement overnight. Deep moisture returns
from southwest to northeast this evening. Expect precipitation to
begin in northwest North Carolina around 00Z/7PM and in Hot Springs
and Buckingham by midnight. RAP/3KM NAM showing a the potential
for a stripe of 1.00 to 1.25 inches of rain before 12Z/7AM
Wednesday. Models have strong isentropic lift in the 295-300K
layer and precipitable water values of around 1.00 inch are
being advected into the area. Will keep probability of
precipitation highest in the 06Z/1AM-18Z/1PM time frame and have
only a small rise in temperatures during the day Wednesday.
Bufkit forecast soundings from the RAP and 3KM NAM showed a deep
isothermal layer at Hot Springs and Lewisburg 06z/1AM to 12Z/7AM.
Snow or a rain/snow mix is possible depending on surface
temperatures. Guidance holds any accumulation of snow to less than
one inch, especially since surface dew points remain at or above
freezing during the precipitation.
Surface through 850MB winds turn the west then northwest on
Wednesday. Downslope component will help end the precipitation east
of the Blue Ridge by afternoon. Upslope clouds will linger in the
mountains throughout the day. If there are breaks in the clouds soon
enough in afternoon over the North Carolina foothills, temperatures
would warm into the 50s.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 135 PM EST Tuesday...
Dry Wedge of Cooler Air.
Weak high pressure will move over the region Wednesday night then
wedge south into the Carolinas Thursday. The frontal system that
will move across the region Wednesday will stall across the
southeastern states into the coast of North Carolina by Thursday
morning. A wave of low pressure will track along this boundary
during the day Thursday. With this low remaining to our south and
dry high pressure wedged over the area, no precipitation is expected
through the period, but thick cloud cover is likely.
With overcast conditions expected Thursday, temperatures will run a
few degrees cooler than normal east of the Blue Ridge to near normal
across the mountains. Normal highs this time of year are generally
in the upper 40s west of the Blue Ridge to mid 50s east. The wedge
is expected to break by Friday afternoon with highs peaking from the
upper 50s to mid 60s.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 145 PM EST Tuesday...
Strong Front Friday Night into Saturday Morning.
A strong cold front will move across the area Saturday morning.
Being a dynamic system, thunderstorms are possible, but since it is
coming across the region during the overnight/morning hours, we will
not have thunder in the forecast. Current forecasted rainfall
amounts range between a half and three-quarter of an inch. Some
light snow is possible behind the front Saturday. Cool dry high
pressure will reside over the region for the weekend, possibly into
early next week. The GFS brings precipitation back into the area
Tuesday while the ECM remains dry.
Temperatures will drop behind the front Saturday and could be 5F-10F
cooler than normal. Do not fret, the cold air does not stick around
long with temperatures recovering to near normal levels on Sunday
and warmer than normal on Monday.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 625 PM EST Tuesday...
Keeping terminals close to the previous forecast which shows all
sites going from mid/high clouds quickly to sub-VFR after 06z,
with rain spreading north. Best rain threat runs from 03z-17z,
and will end from west to east after 17z Wed. Rain will be
moderate at times. Overall cigs/vsbys should be IFR or lower
especially between 09-17z, with lower cigs sticking around
behind this system in the mountains, while things start clearing
out east.
Good confidence for wind, ceiling and visibility through the
period.
Extended Aviation Discussion...
Conditions will continue to improve Wednesday night through
Thursday night behind this system.
A strong winter-like cold front will cross the eastern United
States Friday and Saturday bringing widespread rain changing to
snow showers in the mountains and a lengthy period of sub-VFR
ceilings. Strong and gusty winds appear likely Friday night
ahead of the front and Saturday behind the front. Much colder
air will spread into the area Sunday into Monday with some
improvement in aviation conditions, especially east of the Blue
Ridge.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...AMS/RAB/WP