Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/26/25
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
508 PM CST Sat Jan 25 2025
.KEY MESSAGES...
- Downslope conditions with winds gusting around 50 mph are
possible late Sunday night into Monday morning around the
eastern slopes of the Sisseton Hills, including Sisseton and
portions of I-29.
- Temperatures will average 10 to 25 degrees Sunday through next
Saturday.
&&
.UPDATE...
Issued at 507 PM CST Sat Jan 25 2025
The forecast remains on track this evening. No major changes are
planned.
&&
.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 107 PM CST Sat Jan 25 2025
At 1 PM CST, temperatures are in the teens to low 20s across the
CWA. Skies are becoming mostly sunny and winds are still northwest
at 15 to 25 mph with gusts up to 35 to 40 mph.
Surface high pressure over the region (centered west of this CWA)
will gradually slip south and east tonight, working across the
central plains heading into Sunday morning. Still looks like a
clear/mostly clear sky night ahead with the lightest winds (less
than 15 mph) across the southwestern zones (closest to the surface
high), while higher winds (15 to 20 mph) out across the northeast
corner of the CWA will happen because of the pressure gradient that
exists between higher pressure west/south and lower pressure
north/east. Low temperatures dropping into the single digits tonight
still looks like a good bet right now. Caveat: weak low level WAA is
forecast to occur later tonight, so low temperatures may occur
earlier in the tonight period, and then steady out or perhaps begin
a gradual warming trend (at least out over and west of the Missouri
River valley) after midnight cst tonight. The latest HRRR guidance
suggests a weak lee-of-the-coteau downslope wind event may be able
to get going toward 12Z on Sunday and persist for several hours into
the day on Sunday.
Low level WAA continues on Sunday into Sunday night, with the
potential for a stronger downslope wind event continuing to show up
in the hi-res short-term guidance. Climo is the mid to upper 20s for
highs and the single digits for lows. Based on deterministic and
ensemble-based temperature progs/guidance, readings on Sunday and
Sunday night could end up climbing into the 30s and 40s and teens to
low 20s, respectively; a good 5 to 15 degrees or more above normal.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 107 PM CST Sat Jan 25 2025
Coteau downslope winds are the main concern to open the long term,
but these will be on a downward trend mid Monday morning. Otherwise,
we`re looking at mild temperatures Monday with westerly low level
flow with the northwest flow regime still in place and the
jet/storm track over the Great Lakes with weaker flow aloft
overhead. A weak front comes through later Monday, now with some
cooler air aloft so temperatures are not as warm potentially as
expected in the last few forecast iterations as winds shift to the
west northwest. Thats short lived, with another surge of milder air
aloft ahead of the next shortwave that will be zipping into the
Western Lakes region. That is followed by another backdoor front
which stalls out in the central/western Dakotas. That again is
quickly purged with a shift to southwesterly winds Thursday. Mild
air aloft remains in place for Friday, with a Colorado Low type
system that is starting to take form. Clusters all seem to latch
onto this system, though vary in strength and location right from
the get-go and trend towards weakening as it lifts east northeast to
northeast. The depth of the cold air around the periphery of the
system is also pretty limited and 700mb temperatures currently run
warmer than the dendritic growth zone so precipitation type on the
backside is highly speculative at this point. Confidence remains low
as to whether we will get into the TROWAL of the system and what
amounts/types of moisture we`d be looking at, but there is still a
whole week between now and then for models to acquire relevant data.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 507 PM CST Sat Jan 25 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are expected through Sunday afternoon.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Wise
SHORT TERM...Dorn
LONG TERM...Connelly
AVIATION...Wise
Area Forecast Discussion
National Weather Service State College PA
1026 PM EST Sat Jan 25 2025
.SYNOPSIS...
A period of light snow or snow showers will bring a light
accumulation of snow to the Northwest and North Central
Mountains tonight into Saturday. A stronger system pushes
through Monday night and Tuesday with a blustery wind and
a few heavier snow showers. A third, even stronger, system
moves through Tues night and Wed. An upper level ridge moves
overhead late in the week.
&&
.NEAR TERM /THROUGH SUNDAY/...
Light snow has moved into parts of the NW and WC Mtns this
evening with vsbys generally ranging form 1 to 3 miles in an
expanding area of returns extending from Butler, Clarion and
Jefferson Counties into Elk and Cameron Counties late this
evening. It appears this corridor is most likely to see 1-2"
and a spot 3" isn`t out of the question where the best banding
sets up and resides through the overnight hours, thanks to a
persistent 110kt 200 mb jet. Overall QPF remains quite light,
but up to a few inches of fluff is a good bet into parts of Elk,
Cameron, Nrn Clinton and perhaps McKean and Potter Counties
from this system overnight. Farther east it`s hard to see much
more than flurries that could whiten the ground in parts of the
Central Mountains, but the dry boundary layer is a limiting
factor and most areas won`t see much east of the Alleghenies and
south of the NC Mtns. Overnight temps don`t fall too far from
current readings with the increasing cloud cover and breeze
staying up.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
The exit of forcing and weakening upslope in the morning will
turn off the snow for the Laurels, and then shortly afterwards,
for the NW. Neutral to slight warm advection should keep temps
from being too cold, but also keep them below normals for Sun
and Monday. We`ll be in between systems Sun and most of Monday.
But, a tightening pressure gradient will keep us breezy, and
keep the chill in the air.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A deepening low over northern Canada and building high pressure
over the Central US will generate a tightening pressure
gradient and gusty winds in Pennsylvania by Monday afternoon.
With highs forecast in the upper 30s for much of southeast PA
along with mostly sunny skies, the gusty winds should help erode
away some of the existing snow. Farther northwest, temperatures
will be within a few degrees of the freezing mark.
By Tuesday night, an anomalous 50-65kt 850mb jet will move over
the region and bring the threat for gusty winds, especially in
for locations just east of the highest ridges in the Laurel
Highlands. The ECMWF Extreme Forecast Index highlights locations
west of I-99 and north of I-80 for a heightened threat of
anomalously high wind gusts. The ECENS depicts a 40-50%
probability of wind gusts exceeding 50kts in western Bedford and
Blair counties Tuesday morning. Advisory level gusts (44+ mph)
are most likely across Clearfield, western Centre, Cambria, and
Somerset counties).
A shortwave will to drop south across the region later in the
day on Tuesday, which will reinforce colder air across the
region. An uptick in moisture is expected, outlined in recent
PWAT anomalies, suggesting a round of snow showers along the
associated cold front Tuesday with the best chances across our
northern/western zones. Guidance does continue to indicate
marginal instability across the northern tier of counties,
indicating some snow squall potential later in the day/early
Wednesday morning.
With regards to lake effect snow in the upcoming week, northwest
flow behind the front is likely to produce lake effect snow
showers into Wednesday. Ice cover across Lake Erie will dampen
this potential, with any accumulation across NW PA expected to
be minimal. A clipper may track north of PA on Wednesday, which
will support a quick batch of snow, with lake effect showers
developing later in the day and into Thursday. Wind gusts will
ramp up again Wednesday afternoon in the wake of the clipper,
with more widespread gusty winds compared to Tuesday morning.
The ECENS paints 40% or higher probabilities of wind gusts
exceeding 34 knots across pretty much the entire area.
Forecast uncertainty ramps up considerably Wednesday night into
the weekend as a reinforcing shot of cold air precedes upper
level ridging into the weekend. The coldest solutions bring
another shot of Arctic air into the region with highs in the
teens and lows in the single digits on Thursday and Friday,
while the warmest solutions keep temperatures above freezing
across the southern tier throughout the week.
Heading into the weekend, a broad system of low pressure will
move from the Mississippi Valley into the northeast, but
considerable uncertainty exists in the track, intensity, and
timing. Sounding profiles indicate that precipitation type
forecasting could be complex, with perhaps a higher-than-normal
risk of freezing rain, but it is too early to make any
definitive predictions.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
Currently VFR conditions prevail across all of central
Pennsylvania with light radar returns just north/west of JST/AOO
as of 00Z Sunday. VFR conditions are expected to prevail at
MDT/LNS through 00Z Monday with very high (~90-100%) confidence,
with wind gusts upwards of 20kts possible mainly after 18Z
Sunday.
The bulk of model guidance continues to highlight BFD/JST as
the airfields of most concern for sub-VFR conditions through 00Z
Monday, with recent RAP/GLAMP guidance indicating increasing
probabilities of MVFR ceilings/visibilities between 09-15Z
Sunday. Have decided to outline these conditions in the 00Z TAF
package while also including some potential for IFR ceilings at
BFD after 20Z Sunday based on recent RAP model soundings
outlining saturation in the lower levels. Given slightly lower
confidence (~20-30%) in IFR ceilings at this time, have only
outlined this cloud deck as a SCT layer but as model guidance
comes to more of a consensus, could allow for increased
confidence in IFR ceilings at BFD. The influence of the LLJ will
also bring about increased confidence (~80-90%) in LLWS at
BFD/JST through 12Z Sunday with winds at 925mb tapering down
slightly after sunrise on Sunday.
Across the central airfields (AOO/UNV/IPT), low confidence on
snow making any impacts at the airfield; however, given
observational trends and given the fact GLAMP/RAP model guidance
is in modest agreement, have outlined brief periods of MVFR
restrictions at UNV/IPT with no precipitation mentions or
restrictions at AOO. Low-level wind shear will also be possible
across these airfields in the near-term (through 15Z Sunday) via
the aforementioned LLJ that will also impact BFD/JST.
Outlook...
Mon PM-Tue...Gusty northwest winds. Occnl IFR in SHSN N/W, MVFR
S/E.
Tue PM-Wed...Light snow possible nrn mtns. Snow squalls
possible W Mtns. WSW wind gusts in excess of 35 KTS possible.
Thu...Lake effect SHSN early. Otherwise VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...DeVoir/Dangelo
NEAR TERM...DeVoir/Dangelo
SHORT TERM...DeVoir/Dangelo
LONG TERM...DeVoir/Banghoff
AVIATION...NPB
Area Forecast Discussion
National Weather Service Grand Rapids MI
1003 PM EST Sat Jan 25 2025
.KEY MESSAGES...
- Quick Moving Snow Showers This Evening
- Windy and Snow Chances Monday
- Additional Chances for Snow Tuesday into Wednesday
&&
.UPDATE...
Issued at 1000 PM EST Sat Jan 25 2025
The steeper lapse rates in the 0 to 3 km layer along with a cold
front pushing through continues to support snow shower growth,
even for areas south of I-96. We went ahead and increased the
potential into southern parts of the CWA. Based off of SPC`s snow
squall parameter on their Meso Analysis page, some of the snow
showers could be locally heavy. We have been issuing SPS`s along
the path of these snow showers.
&&
.DISCUSSION...
Issued at 308 PM EST Sat Jan 25 2025
- Quick Moving Snow Showers This Evening
The shortwave trough and associated positive vorticity advection
over northern Wisconsin will gradually move east this afternoon
and evening bringing with it our next chance for snow. There is
some uncertainty on how this system will evolve as it moves into
and through our area. HIRES guidance varies on how far south snow
showers will reach with HRRR and FV3 being the farther south
toward the I-94 corridor while others keep snow chances mainly
north of I-96. We`ll have to monitor and adjust the forecast based
on observations in Wisconsin and as it moves across Lake Michigan.
With the quick moving nature of the snow, not expecting much in
the way of accumulations. Amounts for those who do see snow are
expected to be around a quarter to an inch of snow through
tonight. Additionally there is the potential to mix down some
stronger gusts as seen from observations in Minnesota and in the
RAP and HRRR soundings. Probability of gusts of 40 mph with these
snow showers is 20 to 40 percent looking at HREF probabilities.
With the combination of snow and winds areas could see quick
reductions in visibility, blowing and drifting snow, and light
accumulations before ending late tonight.
- Windy and Snow Chances Monday
Ensembles focus in on Monday for higher than usual winds for
Monday. Looking at 850mb and 925mb southwest winds are around 40
to 50 knots. With this bumped up wind gusts from the NBM with with
some areas seeing wind gusts around 40 mph. There is also a chance
for light snow (20 to 40 percent) Monday. Moisture is deeper and a
week area of positive vorticty advection moves through but the
main vorticity maximum remains north of the area. Any snow looks
to be brief with dry conditions returning Monday night resulting
in only light amounts.
- Additional Chances for Snow Tuesday into Wednesday
A deeper trough and associated positive vorticity advection
gradually work their way into the area later Tuesday into
Wednesday bringing with it colder temperatures and better chances
for lake effect snow within the northwest flow. This could cause
impacts for the Wednesday evening commute.
On the horizon upper level ridging and high pressure move in
behind Wednesday`s snow. Saturday`s wintry mix is still in play as
we move from a cold pattern to a warmer one. Still too early for
exact details, but something to watch as we get closer.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 619 PM EST Sat Jan 25 2025
Snow showers have developed along a cold front crossing the area
and will continue for the next few hours. Gusts will briefly jump
to around 30 knots along the front with pockets of IFR visbys in
the heavier bands. Highest confidence for IFR conditions is near
00z at LAN with the line currently near Y70. Isolated pockets of
MVFR visbys are possible in the light showers behind the front.
Winds go westerly behind the front wit gusts to 20 knots through
the first part of the night. VFR conditions behind the front
deteriorate to MVFR between 06z-10z as 2000-3000 ft cigs arrive
across lower Michigan. Cigs then scatter out to VFR after 19z on
Sunday.
&&
.MARINE...
Issued at 308 PM EST Sat Jan 25 2025
Winds and waves remain hazardous to small craft through the
weekend with a brief period of gales possible this evening.
Looking toward Monday gusty southwest winds are expected with the
potential for gales for most of the day. A Gale Watch has been
issued for Sunday night through Monday night. High waves may cause
ice along the lakeshore to break up.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 7 PM EST Sunday for LMZ844>849.
Gale Watch from Sunday evening through late Monday night for
LMZ844>849.
&&
$$
UPDATE...MJS
DISCUSSION...RAH
AVIATION...Thomas
MARINE...RAH
Area Forecast Discussion
National Weather Service Nashville TN
951 PM CST Sat Jan 25 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 948 PM CST Sat Jan 25 2025
- Normal to above normal temperatures through the next 7 days.
- Chance for light showers Sunday and Sunday night, possibly
mixed with some snowflakes Sunday night.
- There is a better chance of rain late next week.
&&
.UPDATE...
Issued at 740 PM CST Sat Jan 25 2025
The approach of a southern steam shortwave and a cold front from
the northwest will bring increasing clouds through the night.
With the clouds and light southwest winds, lows tonight will not
be nearly as cold as last night.
For Sunday and Sunday night, new data was included with this
update showing slightly higher precip chances area-wide. Most of
the rainfall with the southern stream system will fall south of
our area, but the front coming from the northwest will draw some
of that moisture northward while adding lift by Sunday evening.
Even with greater chances, precip amounts will still be very
light with less than one tenth of an inch. Colder air with the
front will cause whatever light precipitation lingers Sunday
evening to change to snowflakes or perhaps a little sleet. No
significant accumulation or impacts are expected, but higher
elevation north and northeast of Nashville (Highland Rim and
Upper Cumberland) could see a few late night slick spots on
elevated surfaces. Short range models (HREF) have been showing
this potential for several runs, including the latest HRRR 00Z
data.
&&
.SHORT TERM...
(This afternoon through Sunday)
Issued at 1201 PM CST Sat Jan 25 2025
A surface high to our southeast is allowing for plenty of sunshine
today and breezy southerly surface winds. Temperatures will rise
into the upper 40s to low 50s across the area by this afternoon.
This morning was our last dip into the teens for the foreseeable
future! Tonight might see comparatively warm, with lows only in
the low 30s. Southerly flow remains steady tomorrow ahead of an
approaching wave. Expect highs to be just a couple of degrees
cooler than today. Light showers may start to move into our
southern counties late tomorrow afternoon, but the best chance for
light rain will be after 6PM.
&&
.LONG TERM...
(Sunday Night through next Saturday)
Issued at 1201 PM CST Sat Jan 25 2025
A broad area of showers driven east by an upper shortwave will
remain mostly south of us Sunday evening, however areas south of
I-40 have the best chance of seeing light rain Sunday night as the
northern edge of the showers expand into our area. Rainfall
amounts may be just enough to measure. As temperatures fall at the
surface and aloft on Sunday night a few flurries may mix in with
the rain on the northern fringes of any remaining precip. No
impacts are expected.
Another area of high pressure will sink to our south and keep
Monday and Tuesday dry with gradually warming temperatures. By
Wednesday, when our next chance of showers enters the forecast we
could see temperatures pushing into the upper 50s.
The last half of the week is painted with low chance pops, as
models hone in on the timing of the next system. More than likely
we won`t see rain stretch across multiple days. In fact the best
chance for rain after Wednesday looks to be Friday night. It`s
still several days out, but the low pressure associated with next
weekend`s system looks more robust than what we`ve seen lately and
could have the potential for at least some thunder, but we`ll see
how things change in the coming days.
&&
.AVIATION...
(06Z TAFS)
Issued at 948 PM CST Sat Jan 25 2025
With the dry air in place, it looks like it`ll take awhile for
cigs to come down tomorrow. VFR until 20Z when MVFR will start to
spread west to east across the mid-state. All terminals will see
at least this. IFR possible towards the end of the cycle,
especially for SRB/CSV.
Winds will be light (less than 10 kts) throughout with a shift
from the southwest to west by 00Z/Mon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 33 46 31 49 / 0 20 30 0
Clarksville 32 45 25 47 / 0 10 20 0
Crossville 28 44 29 44 / 0 10 30 0
Columbia 31 45 31 49 / 0 30 40 0
Cookeville 30 44 29 45 / 0 20 40 0
Jamestown 28 44 27 42 / 0 10 30 0
Lawrenceburg 29 45 32 48 / 0 30 50 0
Murfreesboro 30 46 31 48 / 0 30 40 0
Waverly 32 44 28 47 / 0 20 20 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......13
SHORT TERM...Whitehead
LONG TERM....Whitehead
AVIATION.....Unger