Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/01/22
Area Forecast Discussion
National Weather Service Columbia SC
1007 PM EST Mon Jan 31 2022
High pressure along with relatively dry air will remain in
control of the region through Tuesday followed by a gradual
warming trend. Daytime temperatures will be above normal the
second half of the week. Unsettled weather associated with an
approaching cold front is expected late in the week. Colder and
drier air arrives behind the front for Saturday.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Satellite still showing few cirrus clouds moving across the
eastern cwa, and those will push east later tonight leaving
mostly clear skies across the forecast area for much of the
night. With light winds, clear skies, and dry air in place,
tonight should see more ideal radiational cooling conditions.
Expect overnight lows in the upper 20s to lower 30s with some
air mass modification.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Tuesday and Tuesday Night: High pressure is in firm control of
the forecast area on Tuesday. Light winds will become easterly
at 5-10mph. Sunshine will be abundant allowing temperatures to
once again rise to near normal values. Expected highs will range
from the mid-fifties to the lower sixties. Increasing
cloudiness Tuesday night will slow radiational cooling somewhat
with lows in the lower to mid-thirties.
Wednesday and Wednesday Night: A significant pattern change is
expected on Wednesday as a potent storm system takes shape over
the Central US. In our forecast area, upper-level ridging
strengthens while surface high pressure moves offshore favoring
an increase in temperatures and moisture. PWATs rise during the
day with values in the 0.75-1 inch range by evening. Clouds
will increase through the day but it should remain dry. Highs
are warmer despite the increasing cloud cover with most
locations ending up in the sixties. Moisture continues to
increase at night and a shower or two cannot be ruled out in
northern and western counties. Lows Wednesday night will be much
warmer then previous nights courtesy of abundant cloudiness and
a modest low-level jet with readings in the mid-forties to
around fifty degrees in the CSRA.
.LONG TERM /THURSDAY THROUGH MONDAY/...
Upper-level ridging holds strong at the start of the long term.
There will be plenty of clouds around on Thursday as a cold
front slowly approaches from the west. While a few showers are
possible, especially in the north and west, most of the rain
should hold off until Friday. Thursday will likely be the
warmest day of the week despite the cloudiness with highs in the
upper sixties to lower seventies. Recent model guidance
continues to slow the progression of the cold front on Friday.
As a result, the week will likely end on a warm and wet note
with a period of rain expected. Saturday will be colder and
drier behind the front. Conditions on Sunday remain uncertain
and it is possible that a wave of low pressure will bring
another period of precipitation to end the weekend.
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
VFR for the most part. Only issue is whether fog prone AGS could
see some fog late tonight. Mostly clear skies except for a
little cirrus. A weak dry surface trough will continue to
slowly shift south through the region, allowing light E/NE winds
to develop. Monday afternoon dewpoints in the upper 20s
indicates air mass a little too dry for significant fog, and
local fog scheme not indicating such. However, latest SREF and
HRRR indicating some potential across the Lowcountry, possibly
into the CSRA. Included a tempo group for MVFR fog at fog prone
AGS later tonight, with limited confidence.
EXTENDED AVIATION OUTLOOK...Low potential for CIG restrictions late
Tuesday night/early Wednesday morning. Increasing potential for some
late night/morning flight restrictions Wednesday/Thursday as a cold
front slowly approaches the region. The best chance of showers and
associated restrictions will be Friday/Friday night with the cold
Area Forecast Discussion
National Weather Service Goodland KS
256 PM MST Mon Jan 31 2022
.SHORT TERM...(This evening through Tuesday)
Issued at 250 PM MST Mon Jan 31 2022
Overview: A complex longwave trough will evolve over the western
CONUS in this period as  shortwave energy currently situated in
Montana progresses E-ENE through the Northern Plains/Upper
Midwest into Ontario --  shortwave energy currently situated in
Washington State digs SE into the Intermountain West -- 
shortwave energy currently situated ~350 mi west of Mt. Shasta, CA
progresses east ashore central CA -- and  a deamplifying upper
level low in the Pacific, currently situated ~1000 mi west Los
Angeles, moves ashore southern CA and progresses eastward into the
Tonight: The latest runs of the HRRR suggest that extensive
orographic cirrus in the lee of the Colorado Front Range will
progress eastward into central KS this evening, with mostly clear
skies prevailing for several hours.. before increasing again AOA
sunrise. Expect lows ranging from the mid teens to mid 20s,
coldest where deep snowpack persists.
Tuesday: Expect a noticeable cooling trend as northerly low-
level flow advects a colder airmass into the region beneath
thickening upper level cloud cover.. with highs ranging from
30-45F.. coldest in the west.
.LONG TERM...(Tuesday night through Monday)
Issued at 202 PM MST Mon Jan 31 2022
For this long-term forecast period, the primary focus will be the
upcoming mid-week winter weather event, along with the dangerously
cold temperatures expected each night during this cold outbreak.
To begin, we will focus on precipitation first. Precipitation should
begin to break out across the region Tuesday night as upper level
lift begins to make its presence felt across the High Plains. This
lift comes in the form of a jet streak/divergence aloft which
promotes upward motion, as seen in omega plots. In addition, it is
possible for some areas of frontogenesis just off the surface that
should promote additional upward motion. Further, a glance at
forecast soundings does indicate some instability/unstable profiles
that could promote moderate/heavy snow at times. In terms of
moisture, there doesn`t seem to be a lack of supply for this event.
throughout the column, saturation of the atmosphere begins as soon
as the event starts, and comes to an end as this system moves
northeast across the US. One thing that is different about this
event is that there won`t be much of a feature to focus
precipitation on, such as the back side of a departing 700 mb closed
low. Overall, it seems the further south and west you go in our
forecast area, the higher amounts will be. Further to the northeast,
in the McCook, NE and Norton, KS areas, dry air will be filtering in
as the Arctic high moves south across the plains, which should limit
snowfall potential and eventually bring this event to a stop as the
air continues its push south. One other thing to note about this
event is the high snow to liquid ratios expected as a result of that
cold air. Climatological snow/liquid ratios of around 12:1 are not
anticipated...instead, our snow/liquid ratio should be around 16:1,
if not slightly higher, which will escalate the amount of snow we
can expect given the QPF/liquid forecast. Overall, the main driver
to increase snow amounts with this event is the higher amount of
QPF/liquid now anticipated. As a result of all these factors, felt
it was a good idea to extend the Winter Storm Watch to the north and
west to account for higher amounts forecast. The snow amount uptick
provided a little uncertainty on whether this will be a long-
duration advisory level or warning level event, so thought moving
forward for 12 more hours with a watch in effect was the better move
given the uncertainty at this time in the liquid and therefore
snowfall amounts forecast. Regarding winds and blowing snow
potential, winds for this snowfall once again appear light although
slightly higher than last week`s event. There could be some isolated
areas of blowing snow, but not anticipating significant reductions
in visibility and drifting.
Regarding temperatures, it still appears as though the forecast for
bitterly cold weather is on track. For this forecast run, there
wasn`t much variation compared to the midnight forecast package,
which gives stronger confidence in the temperatures and resultant
wind chills/apparent temperatures. Highs in the teens are expected
both Wednesday and Thursday, slightly colder on Thursday given the
anticipated snow in place across the region and the closer proximity
of the Arctic high pressure center. Both Wednesday and Thursday
nights will bring low temperatures below zero and wind chills to -15
degrees F, and quite possibly lower. For this forecast run, the
extreme wind chill temperatures have moderated a little, likely
because of slightly lower wind speeds forecast. Without the presence
of a stronger pressure gradient, winds should be fairly light across
the area which should limit how cold wind chills drop...as in
lowering our chances of observing -25 degrees F for the lowest wind
chills. Either way, each morning will be quite cold and appropriate
cold safety procedures should be taken with any morning activities
Beyond this event...beginning Friday, a warming trend will begin as
a ridge of high pressure builds in from the west. As the ridge
builds, any precipitation chances...or systems capable of producing
precipitation...should be blocked, so dry weather is anticipated.
The warming trend will likely be moderated by snow pack once again,
so confidence in how quickly temperatures get back to normal levels
is low. Overall, would plan on near normal high temperatures (mid
40s) returning to begin next week.
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 250 PM MST Mon Jan 31 2022
VFR conditions will rule through the TAF period. Upper level
cloud cover (~22,000 ft AGL) will increase from west-east this
afternoon -- decrease this evening -- then increase again after
midnight. Light (7-13 kt) SW-WSW winds will become variable late
this afternoon (GLD) and early this evening (~sunset at MCK)..
shifting to the NW-NNW at 12-15 knots this evening.. becoming
N-NNE late Tue morning (end of the TAF period).
KS...Winter Storm Watch from Tuesday evening through late Wednesday
night for KSZ001-002-013>015-027>029-041-042.
CO...Winter Storm Watch from Tuesday evening through late Wednesday
night for COZ090>092.
NE...Winter Storm Watch from Tuesday evening through late Wednesday
night for NEZ079.
Area Forecast Discussion
National Weather Service Grand Rapids MI
1054 PM EST Mon Jan 31 2022
Issued at 1029 PM EST Mon Jan 31 2022
No changes on this shift to the going winter headlines. We will be
looking at fine tuning the headlines overnight including the
possibility making decisions on whether to leave the watch in
place and where advisories may be needed.
This system still has a fair amount of uncertainty with it given
it is no where near a classic setup for heavy snow. There is not a
significant mid level wave to key on or a surface low for that
matter. At 500mb`s only channeled vorticity exists with no trough
working through the southwest flow. At the surface, the low is in
the range of 1015mb to 1018mb in Kentucky which is hardly a depth
that is impressive or at location that is would suggest heavy
snow for us.
The reason we will see snow (heavy at times) is due to prolonged
isentropic lift over a surface boundary off to our southeast. The
isentropic lift is driven by upper jet dynamics. There are many
ways to create heavy snow and this is one that is a road less
traveled for us. The period of most concern will be from Tuesday
evening through Wednesday evening. During this time frame there
is a weak 850mb low drifting northeast through Indiana. This wave
will produce a round of moderate to heavy snow across Southern
Lower Michigan. The bulk of the snow with this system will fall
during the Tuesday evening through Wednesday evening time frame.
After that, the boundary and the second low that sweeps up along
the baroclinic zone are further off to the south.
We feel confident in impactful snow across the I-94 corridor with
amounts that will likely be in the 6 to 10 inch range. Certainly
possible to see higher amounts as well, especially towards
Jackson. It is the zone from Holland through Grand Rapids over to
Lansing and Alma where more uncertainty exists. Dry air filtering
in on north winds out of a 1045mb+ Polar High will result in a
sharp cutoff on the north side of the precipitation field. This
sharp cutoff will be near or slightly north of the I-96 corridor
in Southwest Lower Michigan. So, we will be looking through the
latest guidance tonight and adjusting the forecast as necessary.
Again, this system is atypical so there is a bit more uncertainty
than normal at this range in the forecast (about 20-24 hours from
the onset of the snow).
.DISCUSSION...(This evening through next Monday)
Issued at 349 PM EST Mon Jan 31 2022
- One more quiet night weatherwise
A storm is tracking well north of Michigan overnight. There is a
coupled jet feature with that storm. The jet core is passing over
Lake Superior so we will be deep into the warm sector of this
system tonight into Tuesday. Being currently in the right exit
region of that jet feature (mid level subsidence) I do not expect
any precipitation or even that much cloud cover. It will turn
breezy through. The mixing from the systems boundary layer winds
will keep the temperature from falling much tonight even with
minimal cloud cover.
- Rain Tuesday night
As that jet core moves east with the system tonight into Tuesday
we get into the entrance region of that jet (as it strengthens).
Not only that but a southern stream jet comes in phase with it
creating a coupled jet. This results in decent dynamic forcing
(lift with Gulf Moisture feeding into it). That creates an area of
precipitation precipitation from near Detroit to St Louis but mid
afternoon Tuesday. As the cold front trailing the system moves
east it undercuts the warm air so the rain will change to snow
overnight Tuesday. Could be some freezing rain just behind the
The area of rain will track with the cold front at first but
during Tuesday night into Wednesday morning the jet created lift
will sustain the precipitation, deeper into the cold air. That
then starts our snow storm.
There is some question based on some of our HI RES models just how
far north the rain or rain to snow gets Tuesday night into
WEdnesday. The 12z and 18z run of the HRRR give GRR nearly NO
precipitation at all Wednesday. Areas south of a line from
Saginaw to South Haven would get over a 1/4 inch of qpf by 7 am
Wednesday. Other models disagree and have measurable
precipitation over the entire CWA. I would go with the idea that
south of that line it surely will precipitate. Near that line,
rain to snow, then snow is likely during Wednesday morning and
north of that (say north of route 20) I`d expect sprinkles early
Wednesday morning, changing to flurries by sunrise.
- Winter Storm Expected Wednesday into Thursday
We have upgraded the Winter Storm Watch to a Winter Storm Warning
for our southern row of counties since there is excellent
agreement with ensembles for many runs in a row in that area for
the developing wave on the trailing cold front to get far enough
north to bring over a foot of snow over 42 hour period (early Wed
to late Thu). The next row of counties north still looks to have a
high risk of 6 to 12 inches in that time frame but it`s not for
sure there will be 8 inches in 18 hours (warning criteria for
heavy snow). We have let the Winter Storm Watch remain in effect
on those counties. The row of counties north of the watch is
really questionable as to if it will even snow at all (latest GFS
operational run) for whether there will be heavy snow even as far
north as Muskegon to Alma.
Just how far north the snow gets later Wednesday into Thursday is
a result of what happens to our jet exit region and how the
deepening trough just upstream interacts with it. There is still
uncertainty for those counties.
-Dry but cold Friday
The storm should be out of the area by Thursday evening. We get a
large arctic high to follow the storm Thursday night into Friday.
With the center of the high tracking over southern Ontario, north
of Lake Superior we get northeast winds so no lake effect in our
CWA. It will just be very cold. High will be in teens.
- Cold air prevails into the weekend
We will see a progression of Pacific shortwaves for the next week.
That will mean a series of clipper type systems. I would expect
some snow showers from time to time from these systems but timing
and location are questionable. One thing for sure, it will remain
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 647 PM EST Mon Jan 31 2022
VFR conditions will prevail tonight with some mid and high clouds
in place. Bases will be at or above 10,000 feet, so not aviation
concerns. Visibilities will remain VFR given the winds that will
be in place both at the surface and aloft. Stronger winds aloft
will be taking hold, with 40-45 knot south winds showing up at
2,000 feet after 06z. We therefore have low level wind shear in
all of the TAF overnight into Tuesday.
Lower clouds begin to develop over the area around midday on
Tuesday ahead of a cold front approaching from the northwest. The
clouds will lower to MVFR starting around 18z and to IFR starting
around 21z. During the afternoon light rain will break out at many
of the TAF sites, the exception being MKG. Visibilities will dip
to MVFR in light rain and fog. Some low level wind shear will
continue at least through 18z with a southwest wind of 50 knots at
2,000ft. Surface winds will be gusty from the south and south-
southwest most of the day at 15-25 knots.
Issued at 346 PM EST Mon Jan 31 2022
I have continued the gale warning over the northern two marine
zones for tonight into Tuesday afternoon. Otherwise I have a
small craft advisory for the rest of the Near Shore from this
evening into Tuesday afternoon. The strongest winds will be over
the northern 1/3 of our Near Shore Waters from around midnight
through noon on Tuesday. Likely we will have to follow this with a
small craft advisory into Thursday.
MI...Winter Storm Watch from late Tuesday night through Thursday
evening for MIZ059-064>067.
Winter Storm Warning from 2 AM Wednesday to 11 PM EST Thursday
LM...Gale Warning until 1 PM EST Tuesday for LMZ848-849.
Small Craft Advisory until 1 PM EST Tuesday for LMZ844>847.
Area Forecast Discussion
National Weather Service Jacksonville FL
905 PM EST Mon Jan 31 2022
...AREAS OF DENSE FOG POSSIBLE ALONG AND WEST OF I-75 EARLY
Latest RAOB from JAX shows deep northwest to west flow with very
dry airmass continuing. Low level flow is still more westerly to
occasionally southwest, bringing an influx of low level Gulf
moisture. A mid to upper level shortwave ridge is forecast to move
into the forecast area late tonight and Tuesday morning, while a
500 mb closed low moves into the northwest Gulf of Mexico. Sfc
high pressure well north of the area will force a weak, dry cold
front into the north zones late tonight and early Tuesday, with
mainly just a weak wind shift there. Otherwise, the low levels
will decouple and allow efficient radiative cooling and continue
to favor lows that are at least as close to the colder MOS forecasts.
In addition, the fog potential tonight still looks on track and
main change was to expand the fog a bit to the north and east, and
included some areas of dense fog near the I-75 corridor and
points westward, based on new SREF and HRRR guidance.
The current forecast looked on track with fairly light winds and
low seas. Just minor tweaks to update the winds and slightly lower
the seas for the update.
.PREV DISCUSSION [648 PM EST]...
.NEAR TERM [Through Tonight]...
A welcomed and warm, fair weather day across the region with
surface high pressure to our south, straddling the portion of the
peninsula, and a weak area of low pressure to the north. Westerly
breezes have continued around 8-12 mph this afternoon between
those features. Humidity is on the rise as Gulf moisture
undercuts drier air aloft on the westerly flow. The increase in
moisture has lead to some patchy areas of flat cumulus today and
will increase fog potential tonight along and west of the I-75
corridor. Any fog that develops should be fairly shallow and thin.
A weak trailing backdoor front will sag into the area from the
north tonight as the low to the north migrates northeastward into
the Atlantic. Meanwhile, dirty upper ridging will begin to build
overhead tonight, spreading a deck of high clouds overhead.
Despite high clouds, calm conditions overnight will allow temps to
fall into the mid 30s across inland southeast GA tonight, the
upper 30s and low 40s in inland northeast FL, and low/mid 40s near
coast. Patchy frost is expected across inland southeast GA again
.SHORT TERM [Tuesday Through Wednesday Night]...
Stronger high pressure will become established to the north on
Tuesday and turn flow onshore. Increasing moisture will promote
enhance coverage of diurnal cumulus Tuesday afternoon. Weak
coastal troughing will develop amid onshore flow Tuesday night and
may trigger light sprinkle or isolated shower as it shifts inland.
Dominant upper ridging and prolonged onshore flow will support
continued warming through the week as high temperatures ascend
into the 70s Tuesday and Wednesday. Cooler shelf waters in will
keep temperatures a few degrees cooler compared to inland
locations. An uptick in fog/low stratus potential is likely
with the moisture increase but onshore winds may hinder fog
.LONG TERM [Thursday Through Monday]...
Stout upper ridge remains established over the region late this
week as high pressure shifts further away into the north Atlantic.
A weak front will approach from the west and prevailing flow will
become southerly, boosting temperatures even higher toward the
upper 70s and low 80s Thursday and Friday. There is still
considerable variability among guidance on whether the front will
stall across or south of the area this weekend. If the front
stalls over the area, unsettled but warmer weather is expected
this whereas a more progressive front will result in cooler than
normal conditions. Scattered showers are likely to develop along
and ahead of the front but thunderstorm chances are below
mentionable. There remains a lot of uncertainty in the weekend
forecast but it does lean toward the front stalling south of the
area. Though confidence is fairly low on the evolution of the
frontal boundary, an upstream trough is progged to quickly pivot
over the boundary and lift it to the north as a warm front Sunday.
[Through 00Z Wednesday]
VFR conditions prevail at the forecast terminals through at least
06Z Tuesday. Thereafter, guidance still shows potential for fog
development around GNV late tonight, though there is uncertainty
on how low the visibilities will go given the model discrepancy.
(The HRRR and HREF guidance show potential at about 30-40 percent
for less than 1SM, but SREF shows no chance). For continuity, we
kept a chance of IFR vsby 09Z-13Z. In addition, some IFR vsby or
less possible for VQQ late tonight. VFR conditions are expected to
continue elsewhere through Tuesday. Light and variable winds this
evening, then becomes calm. East to northeast surface winds develop
after sunrise Tuesday and becomes sustained at around 5-10 knots.
A sea breeze will attempt to push inland this afternoon and turn
offshore winds to the south in nearshore waters. Winds will
transition to the northeast then onshore as a backdoor cold front
crosses the waters early Tuesday and high pressure builds to the
north. Seas and winds begin to gradually increase on Wednesday as
high pressure will shifts northeast and a frontal system slowly
approaches from the west. Timing uncertainty exists on whether the
late-week front will press into the Marine areas or stall to the
northwest. Scattered showers are expected to develop along the
Rip Currents: Onshore swell will weaken Tuesday but as onshore
winds develop a Moderate Risk for Rips is expected at all area
Surface and transport winds will transition from westerly to
easterly overnight. Sufficient transport and deeper mixing yield
favorable dispersion over the next couple of days. Building upper
ridge and onshore flow will elevate humidity and temperatures
through the rest of the week. Winds will shift southeasterly and
become breezy on Thursday ahead of a slow moving front. Increasing
moisture will increase fog potential, particularly at inland
locations, over the next several mornings.
.PRELIMINARY POINT TEMPS/POPS...
AMG 35 69 45 73 54 / 0 0 0 0 10
SSI 44 63 51 69 56 / 0 0 0 0 10
JAX 39 69 50 73 56 / 0 0 0 0 0
SGJ 44 67 54 72 59 / 0 0 0 0 10
GNV 38 71 48 75 55 / 0 0 0 0 0
OCF 39 72 48 77 55 / 0 0 0 0 0