Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/10/22
Area Forecast Discussion
National Weather Service Bismarck ND
925 PM CST Wed Mar 9 2022
.UPDATE...
Issued at 925 PM CST Wed Mar 9 2022
A few isolated snow showers continue across southwest North
Dakota, mainly from around Beach to Hettinger. It is possible that
some pockets of flurries could continue through the night from
southwest into south central North Dakota due to the presence of a
weak baroclinic zone.
Williams, McLean, and Burleigh Counties have been added to the
Wind Chill Advisory. Not all parts of these counties are likely to
see advisory criteria wind chills, but an NDAWN station in
northeast Williams County is already reporting a wind chill of 25
below, and our current forecast calls for wind chills near 30
below in the northeast corners of McLean and Burleigh Counties.
UPDATE Issued at 619 PM CST Wed Mar 9 2022
Scattered snow showers are expected to diminish with the loss of
diurnal heating this evening. Looking ahead, the most recently
initialized suite of CAM guidance suggests a quicker time of
arrival of the cold front moving from northwest to southeast
across North Dakota tomorrow afternoon and evening. Slight chance
PoPs were sped up to account for this. There does appear to be
some potential for a snow squall event in southwest North Dakota
late tomorrow afternoon. Several ingredients are present in the
latest iteration of the RAP, including strong pressure rises and
low level frontogenesis associated with the cold front, marginally
sufficient low level RH, low level theta-e lapse rates near zero,
and mean BL winds approaching 35 kts. Speaking of winds, they
were also given a slight boost in the forecast tomorrow afternoon
into Friday, utilizing the top half of the latest available NBM
distribution, which does seem a bit higher than previous NBM
iterations. The 18Z HRRR was also blended into the wind forecast,
as it seems to do well with stronger gusts along cold frontal
passages.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 257 PM CST Wed Mar 9 2022
Northwesterly flow aloft will remain the persistent pattern
through the forecast period, however there is a temperature
change in the long term.
Satellite imagery shows CU building over areas where snow pack is
minimal to none. In addition, subtle cyclonic flow aloft and
steeping low level lapse rates are supporting snow showers across
Southwestern ND and south Central ND. Precip chances drop off as
sfc pressure increases and cyclonic flow moves eastward. The sfc
pressure gradient will veer winds out of the West early tomorrow
morning. Thus, Westerly flow and compressional warming are going
to help temperatures rebound temporarily Thursday before the onset
of a front. An upper level trough over Manitoba will progress
eastward opening the door for an Arctic cold front to push into
the area late Thursday afternoon into the evening. This will
reinforce cold temperatures across the Northern Plains. The
frontal passage will increase winds up to 20-25 kts across ND
ushering in bitterly cold winds chills. Therefore, a Wind Chill
Advisory has been issued from 00Z to 15Z Wed. Gusty winds will
also kick up blowing dust across the Northern and Eastern portions
of the CWA temporarily impacting visibility. The aforementioned
cold front is going act as the lifting mechanism, increasing snow
chances across the region Thursday evening. Snow accumulations
will remain low as the cold front will quickly dives into the
Central Plains by Friday morning with surface high pressure
building in behind.
.LONG TERM...(Thursday night through Wednesday)
Issued at 257 PM CST Wed Mar 9 2022
Friday morning wind chills are forecast to drop down to around
minus 30, resulting in frigid temperatures across much of the
region. This could warrant another Wind Chill Advisory. Ridging
begins to build over Western CONUS by Saturday placing the western
portions of ND under the eastern periphery of the ridge. This
will result in a 30 to 40 degree change from the morning lows to
that afternoon highs. Downsloping westerlies winds are going to
help temperatures climb above normal by Sunday afternoon. Sunday
evening, deterministic models have a short wave trough digging
into the ridge bring precip across ND. Ridging will settle in
behind the shortwave trough supporting above normal temperatures
through next week. Tuesday looks to be the warmest day as
temperatures will increase above freezing across the northeastern
portions of the CWA. While central and southwestern portions of
the CWA could see highs in the upper 50s to low 60s. The warm
trend looks to continue in the extended.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 925 PM CST Wed Mar 9 2022
Satellite and surface observations at 03Z suggest an MVFR ceiling
could move over KDIK later this evening, but confidence on this
is not high enough to amend the TAF at this time. Otherwise, VFR
conditions are expected through Thursday morning. A cold front
will enter northwest North Dakota Thursday afternoon, bringing
another chance of snow showers and possible MVFR ceilings across
the state. After a period of lighter winds tonight, southwest
winds will increase to around 20-25 kts by Thursday afternoon,
gusting near 30-35 kts. Wind direction will shift to the northwest
with the frontal passage, which will likely occur at KXWA and
possibly KMOT and KDIK by the end of this forecast period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory until 9 AM CST Thursday for NDZ001>005-
009>013-021>023-025-035>037-047-048-050-051.
&&
$$
UPDATE...Hollan
SHORT TERM...Johnson
LONG TERM...Johnson
AVIATION...Hollan
Area Forecast Discussion
National Weather Service Boise ID
845 PM MST Wed Mar 9 2022
.DISCUSSION...Scattered snow showers continue this evening over
areas east and southeast of Boise. Conditions remain favorable for
additional showers overnight in this same area. Accumulations are
still expected to be light overnight, with a few areas perhaps
seeing an additional inch, but most folks just getting a dusting
or nothing at all. Temperatures will be cold tonight, within a few
degrees of record lows in many areas. All this is handled well by
the current forecast and no changes will be made at this time.
&&
.AVIATION...Isolated MVFR to IFR conditions with snow showers
this evening. Shower activity will diminish around midnight. VFR
conditions expected for much of Thursday. Surface winds: East to
southeast 5-10 kts. Winds aloft at 10k feet MSL: Northeast 40-50
kt.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Friday night...Snow has decreased
to snow showers or flurries that will end in most areas from
north to south tonight with little further accumulation. One or
two more inches may fall this evening, however, in the Camas
Prairie and along the Nevada border. The arctic front has moved
westward as far as Mountain Home, farther west than models
expected, although HRRR has now caught on. The convergence zone
where easterly arctic winds through the Magic Valley meet
northwesterly winds through the Upper Treasure Valley, was
located near Mountain Home and should begin to shift eastward
again tonight. Clouds and light snow showers will continue in and
near the convergence zone and keep temperatures a little warmer
than other areas that clear out. Even so, low temps tonight will
approach records for March 10 from the Snake River south. Wind
chill early Thursday morning will dip to near 10 degrees in the
Snake Basin, 5 below zero to 5 above in eastern Oregon and in the
clearer valleys in western Idaho, but as low as 25 below zero in the
higher eastern basins in Valley and Boise Counties. Thursday looks
mostly sunny after tonight`s clouds shift south, but northern areas
will become partly cloudy again later Thursday. Thursday night will
be clearer than tonight but the arctic air will also be retreating
eastward, so that Friday morning will be no colder than tomorrow
morning, and winds will be lighter. On Friday night warm-frontal
clouds ahead of a Pacific upper ridge will moderate temperatures
further, and begin a significant warming trend into the weekend.
There is no sign that the near-term cold weather will return after
that.
LONG TERM...Saturday through Wednesday...Ridging over the forecast
area will start off the forecast period with dry conditions and
warmer temperatures on Saturday. An approaching trough is expected
Saturday night, which will begin to produce moisture over eastern
Oregon late Saturday. Showers will spread eastward on Sunday, and
could impact much of the forecast area with mountain snow and
valley rain/rain-snow mix. Showers associated with this first
system system should weaken Sunday night. However, active conditions
remain favored as another push of moisture moves toward the
Pacific Coast Monday afternoon, spreading moisture inland through
Tuesday night. Some models show moisture lingering into Wednesday,
though they vary on the coverage of these showers, as well as
their duration. Temperatures through the period will generally
be a few degrees above normal.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise
DISCUSSION...SP
AVIATION.....JS
PREV SHORT TERM...LC
PREV LONG TERM....KB
Area Forecast Discussion
National Weather Service Boston/Norton MA
915 PM EST Wed Mar 9 2022
.SYNOPSIS...
Low pressure exits tonight followed by dry and mild weather
Thursday and Friday. Low pressure moves across southern New
England Saturday, and intensifies into a powerful storm as it
exits the region. The low will be accompanied by periods of
heavy rain that likely ends as snow, especially across western
MA, followed by strong to perhaps damaging winds Saturday night.
Dry, but cold and blustery weather returns Sunday. Next week is
trending as mainly dry weather and temperatures warmer than
normal.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
930 PM Update
Weak returns remain on radar indicate that there are still some
light snow showers over eastern MA. Additional returns on radar
over The Cape and Islands where temperatures above freezing are
resulting in light rain over this area. Expect precipitation to
end in the next hour or so as coastal-low pressure system
continues to pull away. Forecast for tonight remains on track,
but did adjust near-term forecast to reflect latest
observations.
Previous Discussion...
Bands of moderate to briefly heavy snow associated with good
mid level frontogenesis and favorable snow growth lifting north
across SNE. RAP is handling the location of this frontogenesis
quite well and lifts the band north across MA through 00z so
heaviest snowfall will shift to the MA Pike northward through
evening. Expecting accums of a coating to 2 inches in eastern MA
and lower elevations, with 2-4 inches in higher elevations. SPS
sent out for slippery travel across central/W MA, northern CT
into NW RI. While main roads are mostly wet in lower elevations,
as the sun goes down and temps cool, untreated roads will get
coated.
Best forcing exits by 00z as low pres moves offshore from near
the benchmark. Snowfall will begin to taper off early this
evening and end 00-03z from west to east as good mid level
drying moves in. Still some low level moisture lingering
overnight so expect low clouds and patchy fog with partial
clearing toward daybreak.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Thursday...
Weak high pres moves south of New Eng which will bring milder
temps and lots of sunshine as the column is rather dry. 925 mb
temps 0-1C support highs in the upper 40s to lower 50s. Winds
will be light with weak pressure gradient in pace, so overall a
very pleasant late winter day.
Thursday night...
Weak high pres remains in control so dry weather and light winds
will prevail. Mid level shortwave moving through the Great Lakes
and accompanying upper jet will bring some high clouds to SNE,
otherwise mainly clear to partly cloudy skies. Decent
radiational cooling will allow temps to fall back through the
20s, except lower 30s in the urban centers and Cape/Islands.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Highlights...
* Mild and dry weather lingers into Friday
* Periods of moderate to heavy rain ending as snow, especially
across western MA, then strong to perhaps damaging winds late
Saturday/Saturday night
* Blustery and much colder Sunday
* Mainly dry and turning warmer early next week
Overview...
A high pressure over the Great Lakes will steer a low pressure
out to sea Friday, maintaining dry weather across our region.
Likely a little cooler, with more of a northerly wind to start
the day, but still above normal for mid March.
Attention then turns to a low pressure moving across southern
New England Saturday into Saturday night. By Sunday, expecting
this low pressure to develop into a powerful storm over the Gulf
of Saint Lawrence. Once of the questions for our region will be
how quickly this intensification takes place, as the result
could be strong to damaging winds late Saturday into Saturday
night. At this time, thinking the main period of rapid
intensification will be over the Gulf of Maine Saturday evening,
meaning we should be well within range for some stronger winds.
The other concern will be the possibility for some snowfall from
this system. Looking at a couple of windows, mainly across
western MA. The first window would be Friday night as the
precipitation arrives, and the second would be Saturday evening
as this precipitation winds down. Currently thinking that the
daylight hours on Saturday will mainly be rain, due to the more
potent sunshine of mid March. For most, not looking like much
accumulation, especially on paved surfaces. Some uncertainty
remains, there is a possibility for some plowable accumulation
across the higher terrain. The timing and duration will be
critical, and both are aspects to be worked out with later
forecasts.
Turning drier and colder Saturday night into Sunday. Another
round of above normal temperatures expected Monday through
Wednesday with mainly dry weather.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight...Moderate confidence.
Snow ends from west to east between 00-03z. IFR/LIFR cigs and
patchy fog will gradually improve to VFR with partial clearing
from west to east 06-10z, but lower cigs persisting over
Cape/Islands through 12z.
Thursday and Thursday Night...High confidence.
VFR. Light westerly winds.
KBOS TAF...High confidence in trends.
KBDL TAF...High confidence in trends.
Outlook /Friday through Monday/...
Friday: VFR.
Friday Night: Mainly VFR, with local MVFR possible. Breezy. RA
likely, chance SN.
Saturday: MVFR/IFR conditions possible. Windy with gusts up to
35 kt. RA, isolated TSRA.
Saturday Night: Mainly VFR, with local MVFR possible. Windy
with gusts up to 35 kt. Slight chance SN.
Sunday: VFR. Windy with gusts up to 35 kt.
Sunday Night through Monday: VFR. Breezy.
&&
.MARINE...
Forecaster Confidence Levels.
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight...High confidence. N/NE wind 10-20 kt this evening,
diminishing overnight. Seas over the southern outer waters
building to 5-6 ft from SE swell leftover from departing low
pres. SCA will be issued.
Thursday and Thursday night...High confidence. Light winds
expected through the period. Leftover 5 ft seas over the
southern waters will subside during Thu afternoon/night.
Outlook /Friday through Monday/...
Friday: Winds less than 25 kt. Local visibility 1 to 3 nm.
Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Rain likely.
Saturday: Low risk for gale force winds with gusts up to 35 kt.
Rough seas up to 11 ft. Rain, isolated thunderstorms.
Saturday Night: Moderate risk for gale force winds with gusts
up to 35 kt. Rough seas up to 16 ft. Chance of rain.
Sunday: Strong winds with gusts up to 35 kt. Rough seas up to
16 ft.
Sunday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas.
Monday: Winds less than 25 kt. Areas of rough seas.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 3 PM EST Thursday for ANZ254>256.
&&
$$
SYNOPSIS...Belk/KJC
NEAR TERM...RM
SHORT TERM...KJC
LONG TERM...Belk
AVIATION...Belk/KJC
MARINE...Belk/KJC
Area Forecast Discussion
National Weather Service Burlington VT
1014 PM EST Wed Mar 9 2022
.SYNOPSIS...
Light snow across southern Vermont this afternoon will dissipate
this evening after some light accumulations with quieter weather and
seasonally warm temperatures returning for Thursday and Friday. A
potent storm system will impact the North Country on Saturday with
moderate to heavy snow likely.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
As of 1003 PM EST Wednesday...Quick look at water vapor
satellite imagery confirms dry air mass quickly moving in, which
is allowing snow showers to come to an end as we lose our deeper
moisture. The rest of the night should be dry. Was initially
concerned we may see a little drizzle/freezing drizzle, but
latest RAP soundings/satellite indicate less moisture in the low
levels than expected, thus diminishing any threat of fzdz/dz
overnight.
Previous discussion...The forecast continue to play out, well,
as forecast with light snow continuing to very slowly lift
northward into Rutland and Windsor counties as of this hour. The
northward progression of precipitation has been hampered by
very dry air at the surface with dewpoint depressions as high as
20 degrees across central and northern zones. Based on the
latest radar trends and current dewpoint depressions, have a
hard time believing snow will make it any farther north than
Addison/Orange/Essex NY before 00Z where thereafter coastal low
pressure pulls east of the benchmark and takes all the deeper
moisture with it. Where is does snow, a dusting to 2" still
looks reasonable, though mainly on grassy and elevated surfaces
as AOT RWIS road temps across the area are still in the
mid/upper 30s. Exception will be along the southern border of
Rutland/Windsor where some slippery roads are likely. For the
rest of the region to the north, could see some flakes or virga
but no accumulations are expected with just cloudy skies and
temps falling back into the 20s overnight.
Quiet weather returns for Thursday and Thursday night as weak high
pressure builds into the region. Aloft we remain under the influence
of a fast west-southwesterly flow which will keep an abundance of
low/mid level moisture around so skies will vary from partly sunny
to mostly cloudy through the period. Temperatures will be seasonally
warm with highs in the upper 30s to low 40s, and lows generally in
the 20s.
&&
.SHORT TERM /FRIDAY/...
As of 408 PM EST Wednesday...Weak high pressure will continue to keep
quiet weather in the North Country. Near or slightly above
temperatures are expected with light winds and abundant mid level
cloud cover out ahead of the weekend storm.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
As of 408 PM EST Wednesday...High confidence continues for impactful
weather on Saturday due to a major winter storm. On Friday night, a
strong and amplified northern stream shortwave currently in the
Arctic will phase with a southern stream system currently on the
west coast, becoming a full latitude and positively tilted trough
extending from the Great Lakes region to the western Gulf Coast.
Model guidance continues show a surface low forming downstream east
of the Appalachians and tracking rapidly along the east coast from
roughly northern Georgia to Delaware to near New York City in about
12 hours. Ridging ahead of the storm will help tighten the
temperature gradient, with frontogenesis promoting snow on the
northwestern flank of surface low pressure. This zone of snow will
develop across northern New York and spread northeastward into
northern Vermont, initially light but will become moderate to heavy
by daybreak. Periods of heavy snow will persist until the deepening
low pressure center moves into Maine Saturday night. The boundary
layer may be near or slightly above freezing depending on the exact
storm track, with valley rain, mainly southern Champlain and
Connecticut River Valleys, initially favored until stronger
northerly flow develops as the surface low passes to the east during
the day.
Current probabilities for 6 inches of snowfall within 12 hours
exceeds 50% for the entire North Country, so expect winter storm
watches will be issued as soon as tomorrow if trends continue. While
heavy snowfall is expected, the magnitude in a particular location
is difficult to assess with a large spread in model guidance. Our
initial snowfall forecast through 7 PM Saturday consists of the bulk
of the precipitation which ranges from 8 to 12 inches in most of the
forecast area. Historically surface low tracks similar to the one
expected produce heavy snowfall for area. If a more eastward storm
track materializes, the duration of heavy snow in southern and
eastern Vermont would increase. While heavy snowfall is expected,
accumulations will be limited by the relatively short duration of
the heavy snowfall rates given lack of upstream blocking and late
closing off of the 700 millibar low.
Heavy snowfall rates of 1 to 3 inches per hour will occur in
mesoscale bands, causing very difficult travel during the peak of
the event. Snow ratios will likely favor wet snow, becoming a
powdery snow especially if the storm track is on the eastern
envelope of model guidance. Snow will be impacted by increasing
northwest winds, gusting in the 25 to 35 MPH range Saturday night
and producing areas of blowing and drifting snow. Depending on the
snow load, these winds could result in some power outages as well.
Active weather pattern continues next week with variable
temperatures as storm track remains near the North Country. After a
brief cold and blustery Sunday, a quick warm up on Monday is
expected ahead of a weakening clipper system. Depending on the
degree of low level moisture and track of the system, there could be
a round of snow showers. Given the time of year and extent of cold
air, a lot of precipitation chances during the period will be snow
mainly in the higher elevations.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...A coastal low pressure system is spreading
some snow over portions of northern NY and New England as of 630
PM. Mainly affecting KRUT and KSLK with IFR/MVFR visibilities
and MVFR ceilings. May briefly see some snow showers at KMPV,
KBTV, and even as far north as KEFK. Not expecting visibility
reductions to below 6 sm at KBTV, MPV, and KEFK sites however,
given dry air at low-levels, but ceilings will lower to MVFR/low
VFR levels. Can`t rule out a brief snow shower however, but any
flight category reductions would be brief. Meanwhile,
prevailing snow at KRUT and KSLK will quickly come to an end
between 01 and 02Z. Ceilings may be slow to rise above MVFR
levels once the coastal system and the associated snow exits to
the east, especially at KMPV and KEFK. Lingering low ceilings
will finally lift after 12Z Thursday, and primarily VFR
conditions expected through the end of the TAF period.
Winds will generally be less than 10kts through the TAF period
from the south-southwest. Some brief low-level wind shear is
expected at a few TAF sites between 06Z and 12Z with west winds
between 30 and 40 knots around 2000 ft AGL during this time
frame.
Outlook...
Thursday Night: VFR. NO SIG WX.
Friday: VFR. Slight chance SN.
Friday Night: Mainly VFR, with areas MVFR and IFR possible.
Definite SN.
Saturday: Mainly MVFR, with local IFR possible. Definite SN.
Saturday Night: Mainly MVFR, with areas VFR possible. Windy with
gusts to 30 kt. Chance SHSN.
Sunday: VFR. NO SIG WX.
Sunday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Monday: VFR/MVFR conditions possible. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Lahiff
NEAR TERM...Duell/Lahiff
SHORT TERM...Kutikoff
LONG TERM...Kutikoff
AVIATION...Duell
Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
912 PM EST Wed Mar 9 2022
...Evening Update...
The axis of light to moderate rain has shifted south of the CWA
for the most part, with light returns across far southern counties
suggestive of occasional drizzle or light showers. Another
shortwave will traverse the CWA overnight into early tomorrow
(Thursday) morning, supporting a surge of showers across central
Georgia. Isolated to scattered showers remain possible as far
north as the I-85 corridor (including metro Atlanta).
Have updated temperatures and dew points through tomorrow evening
using the CONSShort (RAP + HRRR + LAMP blend) to better capture
the CAD/wedge that is forecast to set up tomorrow. As a result,
high temps tomorrow are generally a few degrees cooler than
previously forecast, especially across northern and eastern
Georgia where the cooler air will be in place.
Previous discussions follow...
Martin
&&
.PREV DISCUSSION... /Issued 707 PM EST Wed Mar 9 2022/
..Updated for 00Z Aviation Discussion...
PREV DISCUSSION... /Issued 237 PM EST Wed Mar 9 2022/
SHORT TERM /Tonight through Thursday Night/...
Busy morning across central GA has wound down this afternoon,
thankfully. Tornado watch was allowed to expire at 1 PM as better
convective coverage to the south is helping to choke off moisture
return and surface destabilization across central GA. Can`t rule
out an isolated thunderstorm this afternoon across far east
central GA, but most likely will just see some light showers
continue to push across the area.
Southwest flow aloft remains in place throughout the short term
with shortwaves quickly moving through western trough and ejecting
into southeast. The shortwave responsible for morning rain and
storms is quickly moving east away from CWA so forcing for sfc
front that pushed into CWA is quickly dissipating, causing it to
mostly stall across central GA. Another shortwave will move
through tonight, spinning up weak sfc low near the gulf coast that
will bring yet another round of rainfall due to isentropic lift
and a small chance of some thunderstorms across central Georgia
tonight with the heaviest push of rain expected in the early
morning hours. Some light showers could come as far north as ATL
metro, though not expecting anything widespread or heavy like this
morning`s rainfall. Rainfall totals across central GA may be up
to an inch, with some isolated higher amounts possible especially
in east central GA. Parameter space is looking much less
threatening than this morning, so while some thunder is possible,
not expecting any severe/tornado threat with this push of rain in
CWA.
Rainfall should clear all portions of the CWA by the late
afternoon with the exception of far east Georgia where some
showers may hang around into the overnight. This respite will be
short-lived, as seen in the long term forecast below. Min
temperatures tonight will be in the upper 30s to 40s across the
north, and upper 40s to 50s in central Georgia where thermal
boundary will likely draw back north a little tonight. Highs
tomorrow will be in the 50s and 60s in the north, and could get
near 70 in south central Georgia. Highs tomorrow in north Georgia
may be tampered a bit by a wedge front expected to push down along
the Appalachians.
Lusk
LONG TERM /Friday through Wednesday/...
Big changes coming as a rather active 24-36 hours is in store for
north and central Georgia to begin this period, with multiple
weather threats/hazards expected.
Friday starts off fairly quiet as sfc warm front sits along the
Gulf Coast/Florida panhandle with a weak "wedge" affecting much of
north GA. As we head through the day and into the evening hours
(Friday), that warm front will surge north ahead of a deepening
upr lvl trough digging into the Lower MS River Valley/Mid South
regions. Expect two areas of precip to develop Friday night -- one
in the warm sector associated with the warm front and then
along/ahead of a strong sfc cold front. Deep-layer shear and
dewpts creeping back up into the lwr 60s across parts of middle GA
will set the stage for another round of strong to severe storms
sometime between late Friday afternoon and early Saturday morning
across our south-central and southeast counties (focused roughly
along and south of a Columbus to Macon to Louisville line).
The other area precip will be developing in the colder air/
deformation region along the 850mb-sfc boundary. Strong low-lvl
forcing coupled with deep H7-5 PVA and 100+kt mid lvl speed max
riding the base of upr trough will support widespread precip along
and just behind the sfc cold front. The cold front should enter
NW GA between 06-12z/Saturday with rain mixing with and/or
changing to snow showers. Given deep-lyr forcing, could see some
heavier mesoscale banding develop for several hours. At this time,
going with 1/2 to 2" of snow - mainly north of a Rome to Jasper
to Cleveland line with a trace to 1/2" possible as far south as
I-20 (west of Atlanta).
The other story will be the wind... given the expected
strengthening of the storm system late Friday night into Saturday,
gradient winds will likely reach "Advisory" levels across the
area. Already predicting gusts in the 25-35 MPH range between
09z/Sat and 00z/Sun.
Saturday night, skies clear and winds diminish as very cold
temperatures grip the area. Widespread lower to mid 20s expected
with teens in the higher elevations of north GA. Wind chills could
dip down into the single digits across far north GA.
Drier and more tranquil conditions will develop and prevail
Sunday through Monday with a moderation in temperatures expected.
Early next week (Monday night/Tuesday), a fast-moving upr lvl
system diving southeast could generate some showers across the
area but impacts are not expected to be significant or widespread
at this time.
DJN.83
AVIATION...
00Z Update...
Cigs have improved to high-VFR at all TAF sites aside from MCN,
where MVFR to low-VFR cigs will persist overnight. At MCN and CSG,
have a PROB30 for -SHRA and MVFR to IFR vsbys between ~09z and
~14z. Have VCSH from ~10z to ~12z at ATL, surrounding sites, and
AHN. Cigs will fall back to MVFR around said time frame at these
sites with brief periods of IFR cigs not out of the question. Cigs
will be slow to scatter out on Thursday afternoon across the
Atlanta metro, while AHN looks to stay socked-in all day. Winds
will be out of the north overnight, generally under 5 kts,
becoming northeasterly on Thursday at 4-8 kts.
//ATL Confidence...00Z Update...
Medium/high confidence on cigs and -SHRA coverage in the morning.
High confidence on all other elements.
Martin
&&
.PRELIMINARY POINT TEMPS/POPS...
Athens 47 58 44 66 / 20 30 10 30
Atlanta 45 60 46 67 / 10 30 10 30
Blairsville 39 60 40 62 / 10 10 5 20
Cartersville 40 63 43 67 / 10 10 5 20
Columbus 50 68 50 72 / 50 40 10 50
Gainesville 46 57 45 64 / 10 20 10 20
Macon 50 66 49 71 / 60 60 20 50
Rome 40 65 42 69 / 5 10 5 20
Peachtree City 44 63 45 69 / 20 40 10 40
Vidalia 58 68 54 69 / 80 90 20 70
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Martin
LONG TERM....DJN.83
AVIATION...Martin
Area Forecast Discussion
National Weather Service Grand Rapids MI
955 PM EST Wed Mar 9 2022
LATEST UPDATE...
Update
.UPDATE...
Issued at 918 PM EST Wed Mar 9 2022
Based on satellite imagery...the clouds have been slow to increase
this evening. We have reflected this in the forecast. It still
looks like skies will turn mostly cloudy by daybreak as the the
500 mb trough slowly approaches from the west. Based on the
limited cloud cover currently...we should still see temperatures
lowering a few more degrees overnight...so the teens still look
possible for northern parts of the CWA with low to mid 20s south.
&&
.DISCUSSION...(This evening through next Wednesday)
Issued at 338 PM EST Wed Mar 9 2022
- Thursday night / Friday light snow continues to trend down -
The snow that spreads in Thursday night and then ends on Friday
continues to trend lighter and lighter. The snow looks to be
confined now to Southern Lower Michigan, or near and south of
I-96. It appears that amounts may end up being less than an inch
in areas that it snows. The snow is associated with some weak
isentropic upglide that is maximized around the morning commute on
Friday along I-94. If there is any impact that occurs from this
snow it would be down there due to some slippery travel.
- Lake effect snow Friday night into Saturday -
A decent setup for some light lake effect snow exists Friday night
into Saturday as cold air pours across Lake Michigan. Delta T`s
will be around 20C during this time frame, so plenty of
instability will be in place. A strong upper trough will be moving
through the region during this time so there should be a synoptic
scale boost given to the lake effect snow. The issue looks to be a
lack of deep moisture. As of right now the moisture looks to be
confined to below 5,000 ft, which obviously is not very deep.
There looks to be a burst of snow Friday night that may be a bit
heavier than what is currently advertised in the models. The
change in the models today is that the wind is a bit more
northwesterly which should bring Western Lower Michigan into play
for some accumulating snows Friday night into Saturday. Given a
moisture depth that is not real deep, thinking several inches of
snow are possible. If the moisture trends up which I think it
might, the accumulations will go up as well. This will be a time
frame to keep an eye on.
- A couple small chances for precipitation beyond Saturday -
The first chance for some light snow beyond Saturday`s lake effect
will be a glancing blow of some light snow Saturday night into
Sunday. The system in question is a clipper and mainly stays off
to our north. Any accumulations will be light and across Central
Lower Michigan. Beyond that there is a low in the models that
moves through the Great Lakes Monday into Tuesday, but there is a
great deal of model spread in the operational models with it. With
marginal temperatures we have rain/snow in the forecast during
this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 553 PM EST Wed Mar 9 2022
A cold front passed through Lower Michigan earlier today and
northwest winds behind it will continue to advect drier air into
the state. We`re looking at VFR conditions through the period.
High clouds will continue to stream in from the southwest as low
pressure develops in the southern Plains. We`re likely to see some
mid clouds with cigs abv 5k ft late tonight and Thursday as the
southern Plains system develops, but lower cigs will remain south
of the terminals.
&&
.MARINE...
Issued at 338 PM EST Wed Mar 9 2022
We have expanded the Small Craft Advisory in area and time. All
zones are now in the SCA and it has been extended through 18z on
Thursday. The 4km NAM, ARW and the HRRR all show stronger winds
moving through tonight. The HRRR Bufkit overview at mid lake
shows a couple different cores of wind around 20 knots. This will
lead to waves of 3 to 5 feet which is why we extended and expanded
the SCA. We expect whitecaps on lakeshore webcams in the morning.
In the mid latitudes there is always the next system and the next
one for us comes on Friday behind a cold front. Strong northwest
winds of 20-30 knots will build waves to 5 to 8 feet.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 1 PM EST Thursday for LMZ844>849.
&&
$$
UPDATE...MJS
DISCUSSION...Duke
AVIATION...04
MARINE...Duke
Area Forecast Discussion
National Weather Service North Platte NE
541 PM CST Wed Mar 9 2022
.SYNOPSIS...
Issued at 327 PM CST Wed Mar 9 2022
A longwave trough of low pressure was the main feature across the
CONUS this morning. The axis of this main trough extended from
central Manitoba, south southwest into northern Mexico. West of
this feature, a strong shortwave trough was present over the Idaho
Panhandle and eastern Washington State. Additional embedded
shortwaves were noted from southern Idaho into Wyoming. Downstream
of Idaho/Wyoming shortwave, strong mid level frontogenesis, north
of an arctic surface front, extended from Wyoming into the
southern 2/3rds of Nebraska. Light snow, with some moderate snow
in the Panhandle was reported earlier this morning. As of this
afternoon, light snow continued generally along and south of
highway 92. As of 3 PM CST, temperatures ranged from 13 at Gordon
to 21 at Valentine.
&&
.SHORT TERM...(This evening through Thursday night)
Issued at 327 PM CST Wed Mar 9 2022
The main forecast issue over the next 24 hours is the continued
threat for snow mainly over the southern half of the forecast
area. Current radar imagery, supported by DOT web cameras,
indicate an end to snowfall across Sheridan and Grant counties.
That being said, have cancelled the advisory for these areas. Will
leave Garden county in a warning, as the southern third of the
county is still seeing light to locally moderate snowfall. With
respect to the remainder of the advisory area, will leave
headlines as is for now as snow, albeit light, continues across
the area. Over the past 3 hours, banding has set up along the I80
corridor from Sidney to Ogallala to North Platte. Within this
area, visibilities were generally from 1 to 3 miles with hourly
snowfall accumulations under a half an inch (this assumes a 20:1
SLR ratio which has been pretty close to our measurements at the
NWS office in North Platte). Looking at the latest short term
model solutions from this morning along with the latest 18z NAM
and 18z HRRR solns, banding along the I80 corridor will persist
for the next 2 to 4 hours, before weakening. A secondary, more
intense band of snow should develop along the KS/NE border mid
evening and transition east northeast overnight into Thursday.
Attm, some amounts up to around 6 inches may be possible in the
southern most portions of Chase, Hayes and Frontier counties.
Given the long duration of the expected snowfall, will not be
upgrading these areas to a warning with this package.
Robust mid level fronto genesis continues this afternoon across
southwestern Nebraska and the southern Sandhills. The strongest
frontogenesis in this area extends along Interstate 80 this
afternoon. A secondary, even stronger area of mid level
frontogenesis will develop over far northern Kansas and far southern
Nebraska later this evening, carrying over into Thursday for south
central into far southeastern Nebraska. Weaker lift will linger into
Thursday morning across far southwestern Nebraska before
transitioning east.
As for the snow forecast, feel fairly confident in what was
inherited with the previous forecast package. Made some tweaks to
snow amounts in the west (Deuel and southern Garden county to
account for the 3+ inches which fell in western and southwestern
portions of those respective counties overnight) and in the south to
account for the expected location of the second band.
An arctic cold front will back into the forecast area on Thursday
night. This will lead to breezy conditions with the fropa overnight.
Resultant wind chills will need to be monitored for Friday morning
as they may bottom out around -15 to -20. Temps will be cold on
Friday under the influence of the arctic airmass as highs will range
from the lower 20s in the northeast, to possibly freezing in the far
southwest.
.LONG TERM...(Friday through Wednesday)
Issued at 327 PM CST Wed Mar 9 2022
A warm front will push across the forecast area Friday night with
much warmer air working into the area for the weekend.
Temperatures will be held back into the 40s Saturday and 50s
Sunday given the expected snow cover. Highs will fall back into
the upper 40s to lower 50s thanks to a weak cold front. Readings
will then bounce back into the 60s on Tuesday as ridging begins to
build east of the Rockies.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 545 PM CST Wed Mar 9 2022
Snow will continue for southwest Nebraska terminals through
tonight, leading to MVFR/IFR and locally LIFR CIGs and
visibilities. The heaviest snow should persist generally south of
an OGA to LBF line overnight. A gradual improvement to VFR is
anticipated by late tomorrow morning for all area terminals. Winds
will remain out of the north through tonight, at around 5 to
15kts.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST /11 AM MST/ Thursday for
NEZ035>038-057>059-069>071.
Winter Storm Warning until 5 AM MST Thursday for NEZ022-056.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...Brown
Area Forecast Discussion...UPDATED
National Weather Service Chicago/Romeoville, IL
907 PM CST Wed Mar 9 2022
.UPDATE...
Issued at 907 PM CST Wed Mar 9 2022
The going forecast into Thursday remains in fairly sound shape.
The main tweak was to inch up the start time of the snow in the
central CWA during the mid-late afternoon into early evening
period. While the signs exist it will start a little earlier and
overlap a portion of the commute in some locations, impacts still
look limited during that time period due to light snowfall rates.
For the rest of tonight, high clouds will be thickening with moist
return aloft ahead of the intermountain trough. Temperatures will
still drop some with gradual cold and dry advection from the
northwest. Going lows of upper teens to mid 20s are on track.
Regional radar imagery from the Central Plains this evening shows
ongoing snow, some heavy, with the tightening mid-level
baroclinic zone near the Nebraska-Kansas border. As the first
impulse approaches the area Thursday afternoon into evening, it
will result in that vertical frontogenetical circulation
extending over our area, though not as robust. The most recent
guidance soundings of saturated depth and omega do hint at a
little earlier onset time of light snow in the central CWA (from
roughly LaSalle County toward Chicago) mid to late afternoon into
early evening. The 00Z HRRR even has 0.04 to 0.08" of QPF by 00Z
from the LaSalle and Livingston Counties through the
western/southwestern Chicago metro, though that may be aggressive
given the low-level dry air. So just a minor speed up in the
forecast at this time, but no changes to amounts or the main
messaging of this upcoming event.
MTF
&&
.SHORT TERM...
Issued at 213 PM CST Wed Mar 9 2022
Through Thursday night...
Modest post-frontal CAA under broad WSW flow aloft has resulted
in a generally seasonable day for early March. An elongated ridge
extending SE from the northern High Plains will edge into the
Upper Mississippi Valley through Thursday as surface low pressure
attempts to form near the OK/TX panhandles. Expansive mid to
upper-level clouds will begin filtering over the area this
evening, but initial cooling within an increasingly dry low-level
airmass should still result in temps falling into the upper teens
northwest to mid 20s southeast.
The mid-level wave responsible for the poorly organized
cyclogenesis in the southern High Plains will lift ENE across the
central Conus while becoming increasingly sheared. Meanwhile,
today`s cold front will stall across the Ohio River Valley while a
narrow upper jet streak shifts mid-MS Valley. The vertical
discontinuity in and lack of coherent forcing will be a notable
limiting factor in precip generation with this system. But a
fairly well organized low-level Fgen response will likely drive a
narrow corridor of light to briefly moderate precip across the SE
2/3 of the CWA very late Thursday afternoon into Friday morning.
Thermal/wet-bulb profiles are supportive of all snow for precip
type, with SLRs 12:1 or less. Expectations are for little to snow
snow near Rockford, to around 1" in most of the Chicago metro, to
1-2" along and south of the Kankakee River. A decent NE feed of
dry air will likely result in a sharp northern cutoff in snow
across northern IL and will also limit lake-enhancement off Lake
Michigan. With all that said, the fairly pronounced and deep Fgen
axis may yield a narrow (on the order of a county or two) axis of
higher snowfall amounts up to 3" around or south of I-55.
Kluber
&&
.LONG TERM...
Issued at 400 PM CST Wed Mar 9 2022
Friday through Wednesday...
Primary concerns for the long term:
* Snow ending south by Friday afternoon.
* An arctic high pushing in an unseasonably cold air mass behind
the snow into Saturday. Gusty northerly winds with the
tightening pressure gradient will cause sub-zero wind chills
early Saturday morning.
* Brief window of lake effect snow showers in portions of our
northwest Indiana counties in the late Friday night through
Saturday morning period.
At the start of the forecast period, light snow will likely still
be ongoing for the southeast 1/3 of the area, though tapering off
NW to SE as the main fgen forcing within the baroclinic zone gets
pushed eastward out of our CWA by an incoming arctic high. The
strong cold front will make its way into northern Illinois by
Friday evening. There looks to be a low chance of snow showers or
flurries along the front but confidence remains low due to
limited moisture, which currently appears likely to greatly reduce
risk for any snow squall activity despite the very sharp Arctic
front.
With ongoing midlevel cold air advection around -20 to -22C
and a north-northwesterly fetch over Lake Michigan, this sets up
the potential for LES in parts of northwest Indiana, specifically
northeast Porter County and points east. Parameters are forecast
to be rather favorable with BUFKIT soundings indicating lake-
induced CAPE around 500-600 J/kg, inversion heights up to 7500ft
and ELs up to 9500ft. Main limiting factor is the limited moisture
and boundary layer wind direction not being ideal, but there is
still time for changes on position/orientation of lake induced
convergence. Timing would be early Saturday morning eventually
pushing out east into Michigan by the afternoon. Potential for
travel hazards in this period would include slippery roads and
reduced visibility.
For the rest of the area, the big story Friday night into Saturday
morning is ramping up of cold air advection (CAA). Gusty NW winds
will bring overnight temps into the single digits and lower teens.
Wind chill values during this time will fall to sub-zero,
bottoming out at -5 to -15F early Saturday, feeling more like
January. Saturdays high temps look to only top out in the mid-20s,
with gusty northwest winds keeping afternoon wind chills in the
single digits and teens above zero.
As the arctic high moves east towards Appalachia, we will see a
windy return flow out of the south behind the high and in the warm
advection region of a clipper passing to our north. As a result,
Sunday will warm up quite nicely back into the 50s. Weak moisture
advection in combination with 25-30kt wind gusts spell a chance
for potential fire wx conditions. If temps overperform and dew
points underperform, some spots could approach Red Flag criteria.
Both of these appear quite possible in this setup, especially if
mixing maximizes.. Area of greater concern in this scenario would
be the far northern IL long term drought areas that will
mostly/entirely miss out on snow Thursday night.
Looking into the work week, ensembles are eyeing another clipper
shortwave moving over the Midwest on Monday. Temps will warm up to
the mid to upper 50s and higher dews will mitigate any fire
weather concerns. Cold front passage Monday evening could have
spotty showers. Tuesday therefore could remain on the cooler side
of temps currently being advertised. More warm return flow on
Wednesday as a clipper is forecast to push to our north. High
temps will potentially climb into the 60s depending on how warm
850 and 925 mb temps are.
BW/JB/Castro
&&
.AVIATION...
For the 00Z TAFs...
Aviation Forecast Concerns:
* Northwest winds become north overnight, and northeast Thursday
afternoon.
* Low probability of high-end MVFR ceilings Thursday afternoon
with a few flurries possible.
* Widespread light snow develops early Thursday evening.
Weak surface cold front had pushed southeast of the terminals late
this afternoon, and will stall south of the Ohio River overnight.
West-northwest winds generally below 10 kts behind the front this
evening will eventually veer north overnight, and northeast
Thursday afternoon as surface high pressure passes north of the
forecast area.
Light snow is expected to develop across southern IA and MO
Thursday in association with an approaching weather disturbance.
This light snow will then spread across northern IL later Thursday
afternoon and evening. Snow is expected to arrive at the terminals
around 00Z, though a few flurries can`t be ruled out during the
late afternoon as the column tries to saturate. Current model
guidance trends indicate that best potential for periods of more
moderate snow and lower visibilities may lay out just south of the
KORD/KDPA area Thursday evening, with lower conditions more likely
farther southeast toward KGYY. Confidence is generally medium with
these details at this time.
Ratzer
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
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Area Forecast Discussion
National Weather Service Marquette MI
657 PM EST Wed Mar 9 2022
.SHORT TERM...(This evening through Thursday)
Issued at 223 PM EST WED MAR 9 2022
Passage of a shortwave and secondary cold front supported some
heavier snow showers earlier today. CAA is underway, and per latest
RAP analysis, current 850mb temps across Lake Superior range from
-13C e to around -16C w. Deeper moisture over the area, upwards of
10kft, combined with increasing overlake instability is resulting in
sct -shsn off the lake. We are now into the time of year where
higher sun angle/increasing solar insolation leads to some
instability over the land as well. Thus, flurries are fairly
widespread across the area even with forcing from shortwave now e of
the area. Under caa, temps haven`t change much since sunrise.
Readings currently range from generally 15-20F w to 25-30F s central
and e.
By 00z, 850mb temps across Lake Superior should range from -16C e to
about -20C w. Deeper moisture will begin to thin out over the w
toward 00z, but at least for the next several hrs, don`t expect much
change from current conditions. Sct w to wnw flow -shsn will
continue off of Lake Superior with sct flurries elsewhere. DGZ will
occupy a good portion of the convective layer to support higher
SLRs. However, even where -shsn are more persistent, expect snow
accumulations to be mostly under 1 inch for the rest of the aftn
into the early evening.
.LONG TERM...(Thursday night through Wednesday)
Issued at 315 PM EST WED MAR 9 2022
LES across the Keweenaw and near Whitefish Point continues tonight
into Thursday as a weak high pressure ridge digs into the Northern
Plains tonight. Expect some cold temps tonight through Thursday
night as anomalously cold air remains over us. Afterwards, a Clipper
system looks to impact our area Friday, followed by LES and another
Clipper system this weekend. As we get into next week, expect to see
temps warm to near the climatological average as the jet stream
trends north and east. More details for the fcst follow below.
Anomalously cold temps are expected tonight through Thursday as
ensembles show 850mb temps in the 10th percentile. Expect lows below
zero across much of the area, with negatives in the double digits
possible in the interior west as skies clear across most of the
area. Due to temps getting down to -20C near 850mb, expect LES to
continue in the the W wind belts tonight, namely in the Keweenaw and
near the Lake Superior shoreline near and east of Grand Marais. Not
much in the way of snowfall accumulation is expected, even though
winds are looking to converge over the lake, as much of the lake is
ice covered in the west and the convergent band should mostly stay
offshore in the east. While the saturated part of the atmospheric
profile in the lower atmosphere is expected to be in the DGZ, the
fluffy nature of the snow shouldn`t lend itself much to increasing
snow totals. Therefore, thinking around a fluffy inch (maybe two) is
expected over the Keweenaw and near the Lake Superior shoreline from
around Grand Marais eastward. As the winds begin to back to the
southwest Thursday due to an approaching warm front associated with
a Clipper system, expect the LES to move offshore by the afternoon
hours. While sunnier skies are expected Thursday, the 850mb temps
below -20C are going to keep high temps below freezing.
A Clipper system approaches the area Thursday night, moving through
Upper MI Friday. This system shouldn`t bring too much in the way of
snowfall across the U.P.; just probably an inch or two. Behind the
Clipper Friday night and Saturday, expect LES to fire back up over
NW wind belts (save for maybe the Porkies westward due to ice
coverage). While the LES should weaken Friday night and Saturday,
could still see a few inches of fluffy snowfall in these areas. Some
blowing snow seems possible in the Keweenaw and east near Lake
Superior Friday night and Saturday as blustery NW winds create said
conditions. Another Clipper system looks to move through Saturday
night and Sunday. Again, not much in the way of impacts is currently
expected; while PWATs (and thus QPF and snow totals) have increased
with this system since yesterday, not really expecting more than a
couple to a few inches across the area.
Early next week, model guidance is showing large divergence in
precip solutions. Therefore, decided to keep what the NBM gave for
precip chances. As for temps, expect a gradual warming trend
throughout the week next week as the jet stream lifts north and east
back over us, allowing warmer air to reach us. While the NBM is
showing 40s early next week and nearly 50F by Wednesday over
Menominee, I have my doubts about the high temps, as snow should
still keep the temps closer to freezing.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 657 PM EST WED MAR 9 2022
VFR conditions have already returned to KIWD and KSAW this evening
with the arrival of drier air. MVFR are, however, lingering at KCMX
and will do so through the night. Despite improving CIGS at KCMX,
the strong winds will continue to blow snow around, reducing
visibilities. Sustained wind speeds through the night at KCMX will
remain strong out of the west at 18 to 22 kts, gusting to 32 kts.
They will diminish a bit around daybreak to 12 kts with gusts up to
21 kts finally weakening below 12 kts late Thursday afternoon.
Elsewhere, the 12 to 15 kt WNW winds at KIWD/KSAW will taper off
over the next few hours.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 312 PM EST WED MAR 9 2022
In the wake of a cold front that has passed, expect w winds to
continue to gust to gale force around 35kt across portions of the e
half of Lake Superior into the early evening hrs. Across the w half
of the lake, wind gusts of 20-30kt will be the rule. Wind gusts will
then generally remain in the 20-30kt range across much of Lake
Superior thru Thu night. With the stronger winds and a late season
arctic air mass moving over the area, hvy freezing spray is expected
over portions of central and eastern Lake Superior tonight into Thu.
The next low pres system tracking e and passing near the northern
shore of Lake Superior on Fri will bring increasing winds. Expect
westerly gale force gusts to around 35kt to develop over western
Lake Superior on Fri. Across central and eastern Lake Superior,
westerly gales of 35-40kt will develop Fri, becoming nw Fri night.
Not out of the question that there could be a short period of high
end gale gusts to around 45kt. These strong winds will bring another
round of heavy freezing spray to central and eastern Lake Superior
Fri into Sat. Winds will gradually diminish Sat and should be mostly
under 20kt on Sun/Mon.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Heavy Freezing Spray Warning until 4 PM EST Thursday for LSZ251-
267.
Heavy Freezing Spray Warning until 4 PM EST Thursday for LSZ249-
250-266.
Heavy Freezing Spray Warning until 7 AM EST Thursday for LSZ243-
244-264.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...TAP
AVIATION...TDUD
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Phoenix AZ
513 PM MST Wed Mar 9 2022
.UPDATE...
Updated Aviation section.
&&
.SYNOPSIS...
Slightly warmer, below normal temperatures expected today along with
continued clear and dry conditions. A relatively dry weather system
is forecast to drop through the region on Thursday and Thursday
night bringing gusty winds to the area, especially across southeast
California and southwest Arizona where blowing dust will also be a
concern. Fair chances for modest precipitation will accompany this
system, primarily from Phoenix eastward. Dry and clear weather
returns Friday followed by a warming trend beginning Saturday.
Temperatures will climb back well into the eighties by early next.
week.
&&
.DISCUSSION...
The RAP 500 mb analysis shows a long-wave trough axis shifting off
to the east with pronounced northwest flow aloft ahead of a large NE
PAC ridge. GOES WV imagery depicts a jet streak and PVA disturbance
to the northwest of the region moving southeast through the Great
Basin ahead of a developing shortwave trough over WA. GOES IR has
clear skies across the area with mostly high clouds moving southeast
with the disturbance to the northwest.
The relatively dry shortwave system drops rapidly through the Great
Basin tonight and tomorrow and into AZ late Thu and Thu night. With
strong high pressure building behind the deepening shortwave the
rapidly tightening gradient will generate very gusty northerly wind
conditions, especially across SE CA to SW AZ. With ensembles
favoring advisory level max gusts of 45-50 mph, the threat of
blowing dust is also likely. As a result, wind and blowing dust
advisories remain in effect for most of SE CA and SW AZ beginning
early Thu afternoon well into Thu night. The advisories also
includes JTNP and the Lower CO River Valley.
There are also fair chances of modest amounts of isolated-scattered
light rain and showers across Phoenix tomorrow evening, and over the
high terrain tomorrow night. This even includes some light snow over
our high terrain east of Phoenix above ~5-6 Kft. The NBM and
ensembles favor <0.05" of rain for the Phoenix Metro area, and <3/4"
of snow for the highest elevations to the east. The favored NBM POPs
have now improved to a fleeting 25-40% after 00Z Fri (Thu evening)
for the greater Phoenix area, and 40-70% for the eastern high
terrain for Thu evening and night. With a dash of very modest
forecast CAPE, the models and NBM also feature non-zero chances for
isolated thunderstorms and convection with this system.
The Grand Ensemble and NBM are in good agreement on just enough cold
air with this system to keep temperatures in a fairly narrow channel
through Fri, and then very good agreement on ushering in a warm-up
starting this weekend into early next week as a strong high
pressure anomaly builds in by Sat across the W CONUS. Cluster
analysis also shows reinforcing high pressure on Mon with highs
punching well into the 80s early next week. Currently the warmest
day is forecast for Tue with highs in the upper 80s to near 90.
Currently there is a 52% chance of reaching a high of 90 degrees
in Phoenix on Tue.
&&
.AVIATION...Updated at 0013Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT
An upper trough and associated cold front will move south through
the Great Basin tonight and then through AZ and southeast CA
Thursday into Friday. In the process, northwesterly flow aloft
will trend toward west and southwesterly and strengthen. At the
surface, anticipate some occasional gustiness (15-20kts) until 02Z
or so before weakening and then trending toward easterly
directions. Sustained speeds during the latter part of the evening
and overnight will primarily remain below 10kts and likely be AOB
8kts for much of the time. With mixing in the late morning,
surface winds will take on a more southerly component and
strengthen with sustained speeds of 10-12kts being common along
with brief localized gusts of 15-20kts. By mid afternoon Thursday,
anticipate winds to become more southwesterly and strengthen some
more with gusts of 20-25 kts common. Anticipate some additional
strengthening by late afternoon with gusts of 25-30kts.
Skies will be clear tonight and through the morning Thursday
before some cumulus develops in the FL080-100 layer in the
afternoon with local broken layers after 21Z. Isolated showers are
possible over the Valley floor confidence in occurrence at any
given location too low to reflect in the TAFs at this time.
Additionally, there could be some lofted dust wafting in from the
west which could potentially lead to a reduction of slantwise
visibilities when the sun angle is low. But, if ceilings are in
place, then that would be less of an issue.
Southeast California/Southwest Arizona including KIPL and KBLH:
An upper trough and associated cold front will move south through
the Great Basin tonight and then through AZ and southeast CA
Thursday into Friday. In the process, northwesterly flow aloft
(above FL100) will remain in place through Thursday afternoon.
Below that, southwest and west winds will strengthen some before
trending northerly in the afternoon and strengthening
substantially. At the surface, anticipate some breeziness (gusts
20-25kts) this evening favoring southwest-westerly at KIPL and
southerly at KBLH. Winds will weaken below 10kts overnight. With
mixing between 17Z-18Z, anticipate strengthening of the winds
favoring northwest directions. This will be followed by more
strengthening by mid afternoon - especially at KBLH with gusts of
35-40kts. Anticipate dust channels (especially over eastern
Riverside County) leading to areas of lofted dust and reduced
slantwise visibilities. With the strongest gusts, anticipate
localized brief surface visibility restrictions of 3-6SM (more
likely at KBLH than KIPL).
&&
.FIRE WEATHER...
Friday through Tuesday:
Behind an exiting weather system, northerly breezy winds are
expected on Friday with high pressure and drying conditions
overtaking the area. Strengthening high pressure will then lead to
a warming trend and continued dry conditions through the rest of
the period. High temperatures should eventually warm to near 90
degrees by next Tuesday. After Friday, winds will be fairly light
day to day, while minimum humidities will be between 7-13% each
day.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Blowing Dust Advisory from 2 PM Thursday to 2 AM MST Friday for
AZZ530-531-533.
Wind Advisory from 2 PM Thursday to 2 AM MST Friday for AZZ530-
531-533.
Blowing Dust Advisory from 4 PM to 10 PM MST Thursday for AZZ532.
Wind Advisory from 4 PM to 10 PM MST Thursday for AZZ532.
CA...Wind Advisory from 11 AM to 10 PM PST Thursday for CAZ560-561-
568.
Blowing Dust Advisory from 1 PM Thursday to 1 AM PST Friday for
CAZ564-569-570.
Wind Advisory from 1 PM Thursday to 1 AM PST Friday for CAZ564-
569-570.
Blowing Dust Advisory from 11 AM to 10 PM PST Thursday for
CAZ561-568.
Blowing Dust Advisory from 3 PM to 9 PM PST Thursday for CAZ563-
565-567.
Wind Advisory from 3 PM to 9 PM PST Thursday for CAZ563-565-567.
&&
$$
Visit us on Facebook, Twitter, and at weather.gov/phoenix
DISCUSSION...Sawtelle
AVIATION...AJ
FIRE WEATHER...Kuhlman
Area Forecast Discussion
National Weather Service Pueblo CO
640 PM MST Wed Mar 9 2022
.UPDATE...
Issued at 621 PM MST Wed Mar 9 2022
Snow is increasing over parts of the Pueblo forecast area and will
continue to do so over the next few hours. Current trends show
two pockets of increased snowfall across the plains, with one
along NE Pueblo, SE El Paso, and NW Crowley counties, and the
other along southern Pueblo County. Radar also shows a boundary
draping southward across Pueblo County. This boundary is likely
the Arctic cold front. Examining current model and mesoanalysis
data, the band along the Pueblo, El Paso, and Crowley county area
is likely driven by 700mb frontogenesis taking place over that
region. The southern Pueblo County band is likely being induced by
stronger upsloping, as the Arctic front pushes up along the
rising terrain in that area. Light to moderate snow is expected
under these bands, which could lead to quicker snow accumulations
on roads and other surfaces. Elsewhere across the plains, lighter
snow is still ongoing and expected given the overall synoptic
ascent with a passing short wave trough.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 306 PM MST Wed Mar 9 2022
Key messages:
1) Bitter cold air spreads across the area tonight, with snow
developing many areas as well.
2) Bands of heavy snow possible tonight and again Thursday
afternoon, especially along and south of the Arkansas River and over
the Wet/Sangre de Cristo Mountains.
3) Winter Weather Highlights remain unchanged from earlier forecast
Cold front through much of eastern Colorado at mid-afternoon, as
surface low pressure sinks southward into New Mexico. Broad upper
trough over the western U.S. has gradually deepened today, with weak
upward motion spreading across most of the area this afternoon. Have
seen mainly light snow so far today, especially back over the
Continental Divide, though deepening low level upslope was aiding in
snow shower generation over the Pikes Peak region, and accumulating
snowfall was noted over Monument Hill as of 2 pm. For tonight, first
piece of upper energy lifts out across the area, though still some
model differences in position of the main snow band this evening, as
forecast location of weak mid level circulation varies between nrn
NM and central CO. In general, stuck close to previous snowfall
forecast, which tracks well with the HRRR/GFS, with the heavy snow
band located from the Wets through Pueblo into Crowley county,
though El Paso county could see a few hours of slightly heavier snow
early this evening, as initial weaker band fills in across the area.
Over the mountains, snowfall will continue overnight, especially
over the Divide as moist w-sw mid level flow continues. Still have
some patchy blowing snow in the grids over the plains, though
surface pressure surge doesn`t look as impressive as earlier
thought, and backed off wind speeds east of the mountains as a
result. Cold air will continue to pour southward across the area
overnight, with temp/wind combination leading to wind chills below
zero at many locations Thu morning. Upward vertical motion weakens
for the first half of the day Thu, and expect snow to taper off to
flurries or end for a period, especially along and east of the
mountains, though clouds will likely persist. In the afternoon, main
piece of energy with the western trough approaches, with snowfall
increasing in coverage and intensity by early evening. Focus for
snow will be over the Sangres/Wets/srn I-25 corridor, where some
pockets of heavy snow look likely as mid/upper level lift ramps up.
Max temps will remain cold across the area, with readings well below
freezing over all but the San Luis Valley.
.LONG TERM...(Thursday night through Wednesday)
Issued at 306 PM MST Wed Mar 9 2022
Key messages:
1) The low pressure system will be exiting the region by Friday
morning, but until then, snow and gusty winds will still be in
place. Very cold temperatures will remain in place and some
locations will have frigid temperatures Friday night.
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. Mid level
northwesterly flow could bring a few snow showers to the northern
Sawatch Range on early on Saturday.
3) A deepening shortwave trough will move quickly across the region
Sunday night through Monday will provide a chance of snow, mainly
over the higher elevations, and a slight cooldown.
4) A well amplified ridge looks to build back in on Tuesday but then
quickly be replaced by troughing advancing towards the region by
late Wednesday. Snow will be possible over the mountains and
adjacent plains Wednesday evening.
Detailed discussion:
Thursday night through Friday night...
Model data has remained fairly consistent with the timing of the
positively tilted major shortwave trough axis moving over the CWA
and being between 09Z and 15Z on Friday (2 AM to 8 AM Friday
morning). With this, there will continue to be impacts from this low
pressure system, beginning with the main brunt of snow over the
southern portion of the Lower Arkansas River Valley, and the
southwestern and eastern mountains around 00Z on Friday (5 PM
Thursday evening). This will then be transitioning to the southern
portions of the CWA throughout the night, with snow ending by around
15 to 18Z on Friday (8 to 11 AM) over the southern Sangre de Cristo
Mountains. Some models indicate that a generous amount of banding is
going to initiate over the southern portion of the Lower Arkansas
River Valley late Thursday evening and then slowly drift southward
and redevelop over the far southeastern plains by early Friday
morning. The NAM 4km Nest also emphasizes on heavier banding over
Huerfano County at around 6-8 PM Thursday evening, along with a
heavier snow band over the central San Luis Valley and Baca County
around this time. The HRRR tends to keep the heavier banding to the
south over western Las Animas County. Depending on where the snow
bands actually establish themselves and the extent of them could
determine which areas to the east see more snow. For instance, if
the heavier banding is over Huerfano and southern Pueblo county,
given the mid level wind flow out of the WSW, Crowley County could
receive heavier amounts, whereas if the banding is further south
over western Las Animas County, Otero could receive higher amounts.
Winds will be initially be out of the NE direction over the plains
during Thursday afternoon and provide better isentropic upgliding,
but then winds will begin to shift to the NW and weaken. This will
reduce the amount of upgliding and snow bands should begin to weaken
in intensity. Winds on the backside of the low pressure center,
which will be southeast of Colorado, will begin to increase due to
tightening of the pressure gradient over the far southeastern
plains. Due to this, and having the polar airmass in place, wind
chill values could be potentially dangerous for a few hours during
the early morning hours over some areas of the eastern plains. A
blend of the BCONSALL and NAM 10 percentile was used to lower
temperatures within the shallow polar air mass that will infiltrate
the plains, bringing low temperatures down to the single digits for
most locations, and below 0F for high country. Another area of focus
for very cold overnight lows will be Wet Mountain Valley, where some
latest model guidance has suggested that Westcliffe could get
down to as low as -20F if there is enough clearing of lower
stratus cloud and radiational cooling.
During the late morning on Friday, snow showers will be more
confined to the southern CWA, and will continue to taper off with
the last remaining showers over the southern Sangre de Cristo
Mountains diminishing by around midday. With the polar airmass still
in place, high temperatures will only warm to around the mid 30s for
the plains and slightly warmer over the Upper Arkansas River Valley
and San Luis Valley. For the mountains, highs will generally be in
the teens and 20s, with single digits for the highest peaks. Higher
pressure will continue to move in with clearing skies throughout the
day.
Saturday through Sunday afternoon...
Some ridging will temporarily begin to build in over the region
throughout the weekend. There will be some residual moisture in the
mid levels and with the predominantly NW`ly flow, due to this, there
could be some light snow showers over the northern Sawatch range
during the early morning hours on Saturday. The downsloping winds
will be to warm most lower elevations back up to around the seasonal
average, especially by Sunday, where some locations will have high
temperatures slightly above average over the southeastern plains.
Sunday evening through Monday...
Models tend to somewhat agree with a minor shortwave at the 500 mb
level that will deepen as it rapidly propagates over the region by
late Sunday evening and throughout the early part of the day on
Monday. This will allow for a cooldown and chance of snow over the
higher elevations, mainly the northern Central Mountains. Being that
the wave will be quite premature, it will be mostly moisture starved
and therefore not expecting for there to be much in the way of lower
level moisture to be present. There is also going to be a chance of
some snow also over the Rampart Range and Palmer Divide. Some of the
GEFS ensemble members are also suggesting that there is going to be
precipitation over the southern plains, but given the orientation of
this trough, at this time there does not appear to be a lot of data
to give confidence that this will occur and therefore the QPF in the
NBM has been removed from this area. Chances are that only virga
will exist over most of the plains and the only impact will be an
increase of winds over the eastern plains, which will become quite
strong and gusty going into the afternoon hours. Cooler for highs on
Monday, and much closer to the seasonal average for this time of
year.
Tuesday through Wednesday...
Model guidance and ensembles are generally showing a warming trend
as ridging occurs over the region on Tuesday. Temperatures look to
be slightly above the seasonal average for most locations for highs
on Tuesday, but then cooling down on Wednesday as the trough
upstream begins to approach the southeast Colorado and breaks down
the ridge. It is still too far out in the forecast period to have
confidence of when this next low pressure system is going to impact
the region, but some guidance and ensemble members suggest that
there will be snow showers moving over the Central Mountains and
adjacent plains as early as late afternoon of Wednesday next week.
-Stewey
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 306 PM MST Wed Mar 9 2022
At KCOS and KPUB, cold front is through both sites, with MVFR cigs
and snow showers developing as of 2130z. Expect steadier snow and
IFR conditions at both sites starting around 00z and continuing
overnight. Some improvement back to MVFR vis Thu morning as snow
becomes light/flurries, then increasing snow intensity will lead to
IFR vis again after 18z-20z. Models have backed off on the strength
of the surface pressure gradient into this evening, and have
lowered gusts into the 15-25 kt range.
At KALS, gradually lowering VFR cigs this evening, with vcsh
starting 02z and continuing through the night. Brief periods of MVFR
cigs and IFR vis possible with any heavier showers. Better chance of
snow and potential IFR conditions Thu afternoon after 18z as snow
spread eastward across the San Luis Valley.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 11 AM MST Thursday for COZ084-085-
089-093-095-096.
Winter Weather Advisory until 5 PM MST Thursday for COZ058>061.
Winter Weather Advisory until 5 AM MST Friday for COZ072>075-
078>080-083-086-087.
Winter Weather Advisory until 11 PM MST Thursday for COZ066-068.
Winter Weather Advisory from noon Thursday to 5 AM MST Friday
for COZ088.
&&
$$
UPDATE...SIMCOE
SHORT TERM...PETERSEN
LONG TERM...STEWARD
AVIATION...PETERSEN