Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/18/22
Area Forecast Discussion
National Weather Service Gaylord MI
1045 PM EDT Sun Apr 17 2022
Issued at 929 PM EDT Sun Apr 17 2022
Ridge axis has pushed just east of Michigan late this evening...
as low pressure continues to take shape over the Northern Plains.
Leading edge of mid/upper level clouds is pushing into Lake
Michigan...with leading edge of precip shield resulting from this
upstream system now reaching the Minnesota/Wisconsin border.
Latest NAM12 and RAP are handling the timing of the arrival of
this precip fairly well...as it the going precip forecast.
Thus...no significant chances to the forecast are needed attm.
Still expect overnight lows will fall into the 20s everywhere...
and sub-freezing temp profile confirms any precip that falls very
late tonight into early Monday will be all frozen. Snow chances
and accumulations late tonight will be confined to our SW CWA and
will be well under a half an inch.
.NEAR TERM...(Through Tonight)
Issued at 309 PM EDT Sun Apr 17 2022
...Chance for snow late nw lower MI...
High Impact Weather Potential...Minimal.
High pressure extends from Hudson Bay, to directly over northern
MI. A few/sct cu out there in most spots, though cloud coverage is
higher near Saginaw Bay. A touch of cirrus is also encroaching on
sw areas. The cu will fade away this evening, but the high clouds
will increase and lower. A pair of shortwaves is helping that
process, one moving eastward toward the OH Valley, and another
digging somewhat across ND/northern MN. These systems are going to
phase in the short-term portion of the forecast. But here in the
near term, the result will be a somewhat disjointed warm conveyor
belt making inroads into western sections of this forecast area
The departure of surface high pressure, and the incoming
shortwaves to our w and s, will contribute to increasing southerly
flow and isentropic ascent. This will produce increasing high and
mid clouds, from sw to ne, mainly after sunset. Nam Bufr soundings
at MBL show only a marginally dry layer up to 6-7k ft by 5am.
Though the bulk of the snow will not arrive until after 8am, there
is a chance of spotty light snow breaking out after 2 am, mainly w
of I-75 in northern lower MI, and in western Mackinac Co. Evap
cooling should remove any lingering above-freezing temps in the
BL; thus precip should be all snow. Only a dusting of new snow is
expected by daybreak; better precip rates will wait until after
Min temps tonight in the mid 20s east to around 30f west.
.SHORT TERM...(Monday through Wednesday)
Issued at 309 PM EDT Sun Apr 17 2022
...Light snow accumulations into Tuesday morning...
High Impact Weather Potential: Low. Accumulations near 1" on grass-
covered/elevated surfaces with locally higher amounts possible.
Ridging will quickly depart to the east as a potent shortwave races
into the Great Lakes/Ohio Valley Monday morning. Favorable upper-
level ascent will support a weak cyclone that will trek over the
area through Monday night. Subsidence on the backside of this wave
will build surface high pressure across much of the Great Plains and
Midwest, and will eventually spread into the Great Lakes by Tuesday
night. Once again, this high pressure will be quickly shunted east
as the next system approaches the region.
Snow is expected to be ongoing at the start of the period across
western portions of the lower peninsula as the aforementioned wave
moves overhead. This round of snow will spread across the forecast
area through the morning and afternoon hours as the system continues
to progress east. Wile the trough itself will provide ample support
aloft, low/mid-level forcing via temperature advection and
frontogenesis are expected to be relatively weak. Additionally,
initial precip will be fighting a dry low-level airmass before it
moistens through the morning. Surface temperatures will be very
close to the freezing mark or slightly warmer, especially during the
afternoon. While a few areas, especially near the lakeshores, may
see rain mix in at times Monday, the dominant precip-type is
anticipated to be snow.
Uncertainty exists with how much falling snow will accumulate on
surfaces such as roadways and sidewalks. With air temps near
freezing, sunshine and 40s the day prior, and soil temps above
freezing, more confidence leads to snowfall melting on contact and
struggling to stay for a period of time for most areas as opposed to
creating travel impacts on main roadways across the area. Overall,
accumulations around 1" or less are anticipated on grass-covered and
elevated surfaces with little more than a trace sticking around on
paved areas. The best chance for accumulations of 2" or more on
select surfaces will come near the Lake Huron shoreline later Monday
and Monday night with any enhancement with easterly flow over the
lake. Additionally, localized amounts of 2" may be possible in
spots of enhanced snow showers in NW lower Michigan on the backside
of the departing system by Tuesday morning. Snow is expected to
diminish across the entire area by Tuesday afternoon. Otherwise,
temperatures will gradually warm heading into the middle of the week
with highs in the mid to upper 40s expected on Wednesday.
.LONG TERM...(Wednesday night through Sunday)
Issued at 309 PM EDT Sun Apr 17 2022
High Impact Weather Potential: Low for now
As mentioned in the short term, a strengthening shortwave will punch
across the Great Lakes Wednesday night and Thursday. A sub-1000mb
low driven by forcing aloft is expected to slide across southern
Canada and over Hudson Bay by Thursday night. An attendant cold
front will sweep across northern Michigan, driving a round of rain
Wednesday evening into Thursday morning. While still several days
away, rainfall amounts look to be around 0.25" or less for most of
the area. Another break in precip chances are expected through the
end of the work week before long range guidance hints at bringing
more rain chances to the Great Lakes sometime over the weekend.
Otherwise, temperatures are expected to be right around average
Thursday and Friday with highs in the mid to upper 50s for most.
Perhaps most exciting is the potential for the warmest temps of the
season at some point over the weekend as temperatures may rise into
the 70s. This will be dependent on warm frontal placement as a
system likely builds to our west, but it is certainly something to
look forward to after the recent stretch of cool days across
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1045 PM EDT Sun Apr 17 2022
Surface ridging currently over much of the Great Lakes will
continue to gradually slide east overnight. Dry wx and solid VFR
conditions are expected overnight...although mid and high clouds
will increase ahead of our next low pressure system entering the
Western Great Lakes region on Monday. This system will bring
widespread rain and snow as well as MVFR/IFR conditions to all of
Northern Lower Michigan for Monday into Monday night. Light/variable
winds overnight will become E/SE AOB 10 kts on Monday.
Issued at 309 PM EDT Sun Apr 17 2022
As high pressure exits eastward, se winds will develop and
increase a bit into tonight, ahead of our next system. Winds/
waves seem likely to come up short of advisory criteria. Low
pressure will strengthen to our east Monday night, and gustier nw
winds arrive then. Small craft advisories will likely be needed.
Area Forecast Discussion
National Weather Service Binghamton NY
750 PM EDT Sun Apr 17 2022
Lingering rain and snow showers taper off by the evening while
skies continue to clear. Sunny skies Monday morning give way to
increasing clouds and rain into the afternoon, changing over to
snow into the evening and night. Accumulating wet snow is
possible Monday night into Tuesday.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
730 PM update...
No significant changes made to the near term forecast. Adjusted
overnight lows tonight a few degrees, but otherwise, the
forecast remains intact.
330 PM Update...
A few lake effect rain and snow showers remain apparent on
radar, but with increasingly drier air at the surface
(dewpoints falling into the 20s) much of this is falling as
virga. As high a ridge continues to build in behind the exiting
upper trough, however, lingering showers should wrap up
entirely over the next couple of hours. Otherwise, with better
mixing and steeper lower level lapse rates, some stronger winds
have been able to mix down to the surface. Expect wind gusts
especially across the higher terrain to be able to reach into
the 20 to 30kt range the rest of the day before winds turn
calmer around/after sunset.
Decreasing winds, clearing skies, and a cooler airmass over the
region will all contribute to efficient radiational cooling
tonight leading to overnight lows in the 20s.
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
***Late season winter storm impacts the region Monday night into
The evolution of a late season winter storm on the northeast coast
is the main concern for this time period. Overall, the basic
dynamical set-up is a classic. A strong upper level short wave
will drop from the upper Plains to Great lakes/Ohio valley on
Monday as a low-level cyclone spins up over the southeast U.S.
The northern branch wave will capture this southern branch
feature as it takes on a negative tilt. This will enhance the
upper divergence over the northeast and lead to cyclogenesis on
the east coast. Models indicate that the surface low will really
begin to deepen as it tracks up the middle Atlantic coast and
eventually into New England Tuesday. The key factor in all this
is where does the mid-level cyclone close off? Typically I look
at where the 700 mb low closes off in these major storms. Just
east of the 700 mb low track is where the
deformation/frontogenetical forcing will be maximized. Cross
sections normal to the isotherms (just used the NAM12 for
reference) show sloped frontogenesis up to 500 mb and negative
equivalent potential vorticity above the frontal zone as the
low-level cyclone tracks toward Long Island/NJ. This is all
classic for a heavy mesoscale snowband to form and eventually
wrap around the 700 mb low. The NAM suggests banding across much
of central NY but I believe the NAM12 would keep the heaviest
snow across northern NY and farther west in central NY than what
it depicted. The 12z GFS suggests this frontogenetical setup
forms farther east than 12z NAM from the Catskills north to VT.
The 06z Euro and 06z euro ensembles and 12z HRRR have a
developing 700 mb low over eastern NY which would suggest
heaviest snow in central NY to north central PA. The CMC is
similar to the GFS. The GFS ensemble mean is similar to the OP
run. CMC ensemble mean is maybe a bit farther west than its OP
run with the heavier snow. The 12z Euro has similar placement as
the 06z run but has backed off on amounts some.
The basic scenario timing wise would be a mix of snow and rain
(probably elevationally dependent) will spread north across
central NY and northeast PA Monday afternoon. Then Monday night
and very early Tuesday a widespread area of snow with a
potential heavier mesoscale snowband sets up now which ends by
around 7 to 10 am Tuesday. So what to do at this point? We will
definitely expand our briefing to a full multi-page PDF. We are
planning a webinar for Monday afternoon for our core public
safety officials as far as decision support services go. Since
there is significant potential for a heavy wet snow that would
be disruptive to not only travel but also power we are opting
for a winter storm watch for Oneida County south to Sullivan
County in NY and also Chenango/Madison in NY and northern Wayne
in northeast PA where there is a lot of high terrain. Biggest
uncertainty is how much farther west and south does the heavier
snow make it. We will emphasize in our winter storm watch
statement that there will be higher snow amounts over the higher
terrain and less in the valleys.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
330 PM Update...
By Tuesday evening, the surface low will be moving north/northeast
out of New England, but wraparound moisture, in addition to breezy
west/northwest flow, will keep in chances for rain and snow showers
downwind of Lake Ontario through much of Tuesday night. Additional
light snow accumulations generally below an inch are possible.
Expect another chilly night as temperatures bottom out in the lower
A large ridge then builds over the region Wednesday and brings a
return to dry weather, and high pressure will remain the dominant
feature over the region the rest of the week with a gradual warming
trend as temperatures finally climb above normal by the end of the
week. There is a chance for some rain showers Thursday as low
pressure moving through Ontario and into Quebec drags a cold front
towards the region, but rain may for the most part remain north of
our area as this quick-hitting system would have to contend with the
robust ridge over the region. We will be experiencing a tightening
pressure gradient for Thursday, however, so winds shifting to the
south will turn gusty. Friday night into Saturday, a warm front
grazing the area may touch off a few more showers especially across
our western zones while the ridge axis begins to shift eastward.
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A few puffs of clouds remain around the Southern Tier and should
dissipate within the next hour or so. VFR conditions are
expected through the overnight into the early afternoon. Clouds
begin to roll in from the SW in the early afternoon, with ELM
seeing BKN skies by noon. Rain moves in late in the afternoon,
dropping conditions to MVFR at ELM/ITH/BGM/AVP. SYR and RME
remain VFR through the forecast period.
Monday night through Tuesday evening...Restrictions likely with
IFR ceilings and visibility as rain changes to snow late monday
evening into Tuesday.
Tuesday night thru Wednesday...Mainly VFR.
Thursday and Friday...Mainly VFR, but stray rain showers with
associated restrictions possible mainly across central NY
PA...Winter Storm Watch from Monday evening through Tuesday morning
NY...Winter Storm Watch from Monday evening through Tuesday morning
Area Forecast Discussion
National Weather Service Billings MT
218 PM MDT Sun Apr 17 2022
Tonight through Monday night...
Satellite imagery shows broad cyclonic flow/troffing over our
region, with main shortwave departed long ago to our east. We are
starting to see height rises from the west, but there is enough
diurnal instability to create isolated-scattered snow showers over
our central and west parts thru around sunset. HRRR continues to
show 100-200 j/kg of sbcape, and boundary layer convergence as
winds continue to veer to the N-NE over the next several hours.
BLX radar already showing NW flow banding downwind of the Crazy,
Belt & Snowy Mountains. Heads up for anyone out and about today,
and this includes in the Billings metro area as briefly moderate
snow showers are possible. Otherwise, we continue to see NW wind
gusts near 40 mph at Baker, Ekalaka and Sheridan...and even a 51
mph gust at Alzada. These gusts should be at their max now, and
mixed winds should gradually decrease between now and sunset.
Winds will be light tonight.
Building upper ridge will bring dry conditions Monday and Monday
night, with low level winds turning easterly. Tonight will be
chilly as surface high builds in, and there seems to be one more
opportunity for a record low at Miles City (forecast is 12F and
record is 15F). Billings record of 20F will be approached but
increasing high clouds overnight may keep lows a bit above that.
Monday will be warmer with temps in the 40s to mid 50s...warmest
in the south at places like Sheridan and Lodge Grass where today`s
satellite imagery shows more and more bare ground. We should see
lows into the 20s or low 30s tomorrow night.
Tuesday through Sunday...
Southwest flow ahead of a trough will boost temps Tuesday with
highs in the mid-50s to lower 60s. By midday Tuesday, winds will
shift out of the NW behind a weak cold front with some brief
showers to follow as a closed upper low scoots across southern
Canada. There is a short window for some snow showers across lower
elevations overnight Tuesday into Wednesday morning, but with
daytime temps staying well above freezing, impactful snowfall is
not expected. Dry westerly flow is restored after the low exits
and an upper ridge builds back in during the day Wednesday with
temps slightly cooler - upper 40s to lower 50s. Into the peak
heating hours of Wednesday afternoon and early evening, some
isolated convective showers are possible given steep low level
lapse rates of 10 C/km and moist northwesterly flow.
By Thursday, attention turns to a vigorous upper low that will be
moving into the western US. Precip should start to become more
widespread Thursday evening into Friday morning as large-scale
ascent increases due to the influence of the left front quadrant
of a jet aloft. Most of this event looks to start out as rain for
lower elevations before transitioning to snow sometime later on
Friday. Ensemble guidance suggests that 850 mb temps will be
flirting with the freezing mark, so it is tough to say exactly who
will see the transition to snow and when at this point. The real
fun begins Friday as guidance continues to show the low rapidly
deepening as it moves out of the Rockies. Exactly where the low
ends up is still slightly uncertain, though it does seem like
models are starting to converge on a solution which brings at
least some widespread and prolonged precip to the area. Depending
on where exactly the low is on Saturday, eastern zones could see
another decent snow event. Not along the lines of what was seen
last week, but a good storm for this time of year. The next couple
of days will be key to start narrowing down specifics, so stay
tuned to the forecast. The low moves out completely by Sunday with
a warm up to start the following week.
Area of MVFR ceilings from KMLS to KBHK will improve to VFR this
afternoon. Expect scattered snow showers from KBIL-KSHR westward
this afternoon and early evening...producing local MVFR at lower
elevations and frequent mountain obscurations. Building high
pressure will bring improvement to VFR regionwide tonight and
Monday. Breezy W-NW winds w/ gusts 25-35 knots will decrease
gradually late this afternoon. Look for light winds after sunset
tonight, then easterly winds gusting 15-20 knots tomorrow.
.PRELIMINARY POINT TEMP/POPS...
Mon Tue Wed Thu Fri Sat Sun
BIL 020/048 029/058 029/053 030/053 036/047 033/047 032/053
20/E 01/E 30/U 02/O 45/R 44/O 33/O
LVM 022/048 034/053 026/051 032/053 034/048 032/048 031/052
20/E 07/R 30/N 15/O 45/O 44/O 33/O
HDN 017/052 027/063 028/055 028/058 034/048 030/047 029/053
20/B 01/E 30/U 02/R 45/R 44/O 33/O
MLS 012/044 032/057 031/050 027/055 034/045 029/043 028/048
00/B 00/E 10/N 01/E 34/R 54/O 32/O
4BQ 017/048 032/064 032/052 029/059 037/046 031/042 029/048
00/B 00/E 30/U 01/E 43/R 44/O 33/O
BHK 010/041 027/054 029/047 021/049 031/043 027/040 025/043
00/B 00/N 10/N 01/N 44/R 44/O 33/O
SHR 020/054 032/065 028/053 029/061 034/049 029/046 028/050
20/B 00/B 50/U 12/O 45/R 54/O 33/O
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
1004 PM EDT Sun Apr 17 2022
Isentropic ascent resulting in some light showers and virga this
evening with dry air across the boundary layer. Moisture will
increase overnight with likely rain showers and a few
thunderstorms possible for the southern half of the forecast area
where RAP forecast soundings indicate MUCAPE around 1000 J/Kg late
tonight. With marginal instability and bulk shear of 30 to 35 kt,
severe weather is unlikely, but any stronger storms could have
some gusty winds and small hail later tonight into Monday morning
near the Chattanooga area. Made some minor updates to PoP timing
and temperatures this evening, but otherwise, forecast continues
00Z TAF DISCUSSION.
MVFR conditions expected later tonight as rain showers, and a few
thunderstorms, move into the area from the southwest. Gusty SE
winds will be possible in the vicinity of TRI later tonight ahead
of the rain showers. Behind this system, winds shift to the NW
late in the period with gradually improving cigs to VFR from west
to east on Monday afternoon.
/ISSUED 333 PM EDT Sun Apr 17 2022/
SHORT TERM...(This Evening through Monday)...
1. Very dry air mass across much of the area with dewpoints in the
upper teens to 20s over southwest VA and northeast TN. Relative
humidity values have dropped in the 20s. The dry Planetary
Boundary Layer (PBL) will inhibit any rainfall initially until the
mid and lower levels moisten.
2. Widespread showers will move into the region overnight through
Monday morning. Embedded thunderstorms expected, especially areas
along and south of interstate 40.
3. Increasing boundary layer jet overnight/Monday morning over the
southern Appalachians. Strongest winds will be across the northern
Cherokee Mountains/Foothills and Southwest VA. Bristol Motor
Speedway campgrounds will likely experience some strong gusty winds
late tonight/Monday morning.
For this Evening, dry air mass in place across much of the area
which will keep rain chances limited initially with a good deal of
Virga anticipated. Driest airmass over southwest VA/northeast TN
where relative humidity is in the 20s to upper teens.
For Tonight, fast moving short-wave will move across the region with
associated frontal boundary. Main forcing is from the left exit
region of the upper jet producing an area of cyclogenesis over
Kentucky with an inverted trough over the region. The pressure falls
will tighten the pressure gradient over the southern Appalachian
with the 850mb jet strengthening to 40 to possibly 50kts. The
southerly winds will help pull moisture and elevated instability
into the area. HREF MUCAPE increase to 250-500 with mid-level
lapse rates approaching 7 degree C.
The increasing elevated instability will produce embedded
thunderstorms with the widespread area of showers. The increasing
850mb jet and associated tightening pressure gradient will produce a
mountain wave event, especially with the northern half of the
Tennessee Mountains/Foothills and southwest Virginia. Have extended
the wind advisory into southwest VA and northeast TN. The strong and
gusty winds may extend into the campgrounds of the Bristol Motor
For Monday, The frontal boundary and upper forcing will begin to
exit the area in the morning. Widespread showers over southwest
VA/northeast TN in the morning will exit the area. Shower activity
will diminish by afternoon with slow clearing up the Tennessee
valley. Cooler conditions are expected.
LONG TERM...(Monday Night through Sunday)...
1. Below normal temperatures to start the period, with a gradual
warming trend beginning mid-week. Well above normal temperatures
expected by the end of the week and into the weekend.
2. Possible frost Monday night/early Tuesday morning. Due to light
winds sheltered valley locations will be most likely to see some
frost. Better chance for frost looks to be Tuesday night/early
3. Most places will remain dry throughout the majority of
the extended, with increasing PoPs late next weekend.
To begin the long term period, a negatively tilted upper level
trough will extend from the Great Lakes region into the southeast
CONUS. Surface low pressure will be exiting to the east while high
pressure builds in from the west. This setup will lead to deep
northwesterly flow and result in below normal temperatures through
Tuesday night. In regards to frost Monday night; current thoughts
are patchy frost mostly in sheltered valleys/locations. With the
surface low still in process of departing, a strong enough PGF will
be in place to keep light winds through the night. Tuesday night
will be the coldest night as the high pressure centers over the
region, leading to more favorable radiational cooling among clear
skies and light winds.
Heading into the mid week, temperatures will be on a gradual
increase associated with rising H5 heights. Expect near normal
temperatures on Wednesday, with highs a few degrees above normal by
Thursday. Additionally, guidance suggest that shortwave energy will
help drive a weakening front towards the region Thursday morning.
While most favorable synoptic support remains well to the north, NBM
does bring slight chance PoPs up to the KY/TN/VA border with impacts
for the majority of the valley to just be increasing cloud coverage
at this time.
Ridging will continue to amplify into the beginning of the weekend,
with well above normal temperatures expected by Friday. Deepening
low pressure across the northern plain states on Sunday will again
drive a frontal boundary to the region by the tail end of the
period. Similar to that on Thursday, the favorable synoptic support
looks to remain well to the north. Additionally, there are quite
notable differences between long term guidance of the GFS and
ECMWF(both in amplitude and in timing). Nonetheless, increasing PoPs
Sunday afternoon, however, confidence in any impacts and timing
remain low at this time.
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 53 66 40 64 40 / 90 20 0 0 0
Knoxville McGhee Tyson Airport, TN 52 62 37 61 37 / 100 50 0 0 0
Oak Ridge, TN 51 62 37 61 37 / 100 40 0 0 0
Tri Cities Airport, TN 45 55 35 56 33 / 100 90 10 0 0
TN...Wind Advisory from 1 AM to noon EDT Monday for Cocke Smoky
Mountains-Johnson-Northwest Carter-Southeast Carter-
Wind Advisory until 6 AM EDT Monday for Blount Smoky Mountains-
Sevier Smoky Mountains-Southeast Monroe.
VA...Wind Advisory from 1 AM to noon EDT Monday for Russell-