Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/04/25

Area Forecast Discussion

National Weather Service Columbia SC

 1025 PM EST Mon Feb 3 2025

.SYNOPSIS...
Warm and dry conditions continue through Tuesday, followed by a
possible Cold Air Damming event on Wednesday. Well above normal
temperatures return Thursday through Sunday. Multiple weak
disturbances bring the chance for rain showers for the end of
the week and into the weekend.

&&

.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
Key Message(s):

- Slight fog potential again across the southern Midlands and
  CSRA.

Zonal flow aloft continues overnight with a dry airmass in
place. The exception may be some low level moisture advecting in
from the coastline, where dense fog has been ongoing for the
last several hours. The latest HRRR depicts some reduced
visibilities across mainly the southeast portion of the forecast
area, but only some isolated areas where visibilities may drop
below 2 or 3 miles. Additionally, a low level jet of 30-35 kts
may keep the boundary layer mixed enough to ward off the threat
for fog. Otherwise, it should be a quiet night with milder
temperatures, so only expect lows in the upper 40s to near 50.

&&

.SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Key message(s):

- Warm and dry conditions expected on Tuesday.

- A Cold Air Damming event results in a cloudier and cooler
conditions on Wednesday, with showers possible later in the day and
into Wednesday night.

Tuesday and Tuesday Night: Upper ridging and high pressure at the
surface will keep the region dry. Any fog at daybreak should
dissipate by midday leading to abundant sunshine. This allows
temperatures to warm well above seasonal values with forecast
highs in the mid to upper 70s. Clouds increase Tuesday night
limiting radiational cooling and keeping overnight temperatures
above normal as well. Forecast lows will range from the mid to
upper 40s in the northern Midlands and Pee Dee and upper 40s in
southern Midlands and CSRA.

Wednesday and Wednesday Night: Latest guidance has become
increasingly bullish regarding the potential for a cold air damming
event. Strong high pressure over New York will push south along the
spine of the Appalachian Mountains, likely ushering in a backdoor
cold front keeping clouds the in place. Temperatures are expected to
be around 10 degrees cooler than Tuesday, albeit still above
seasonal values. In addition, a passing shortwave to our north could
trigger some showers late Wednesday into Wednesday night with the
highest probabilities across the northern Midlands and Pee Dee
region.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Key Message(s):

- A series of weak disturbances could bring showers to the region
during the late week period and into the weekend.

- Temperatures through the period remain well above normal for early
February.

The extended will feature the passage of several weak disturbances.
These features could bring showers to the region each day. Enough
instability may be present for a few thunderstorms as well,
especially on Friday afternoon when the probability of CAPE in
excess of 250 J/kg is highest. Despite the unsettled weather,
confidence remains high in well above normal temperatures Thursday
through Sunday. A cold front approaches near the end of the long
term which may usher in a much colder and drier air mass.

&&

.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Fog-stratus possible at AGS/DNL/OGB Tuesday morning, otherwise
VFR. LLWS likely around 12z Tuesday at all sites.

Light surface winds will continue overnight into Tuesday
morning but a pronounced low level jet will develop overnight.
LLWS likely to develop from roughly 09-13z Tuesday, with a 35-40
knot west-southwest jet max around 2k feet for all TAF sites.
Clear skies are expected to continue at CAE/CUB through the
period, but some stratus-fog is possible at AGS/DNL and
especially OGB again from roughly 09-13z. Given the strength of
the low level jet, stratus would certainly be favored over
traditional fog but MVFR vsby-cigs are possible regardless.
While confidence is not very high, a tempo group is justified
given the otherwise favorable stratus setup; confidence is not
high enough for an IFR mention as of 03z. Any lingering
stratus- fog will clear out quickly Tuesday morning, with VFR
conditions likely at all sites by mid- morning.


.EXTENDED AVIATION OUTLOOK...No significant restrictions
expected at this time.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...




AREA FORECAST DISCUSSION

National Weather Service Jackson KY

 1035 PM EST Mon Feb 3 2025

.KEY MESSAGES...

- Normal to well above normal temperatures will prevail for the
  next week.

- Showers and possibly thunderstorms are expected late Wednesday
  through Thursday evening, and again this weekend.

&&

.UPDATE...
Issued at 1035 PM EST MON FEB 3 2025

Changes were minimal for the late evening update. Current
temperatures in some of the usual cold spots have dropped below
the forecast lows by a couple of degrees, so have lowered
overnight minimum temperatures accordingly.

Low clouds are developing as expected and will continue to
overspread eastern Kentucky over the next several hours, with
drizzle, sprinkles, or light rain possible with a frontal passage
late tonight into early Tuesday.

UPDATE Issued at 726 PM EST MON FEB 3 2025

The forecast is on track, with no significant changes to note with
the early evening update.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 445 PM EST MON FEB 3 2025

Late this afternoon, a broad trough extended from eastern Canada
south across the Great Lakes to the OH valley, mid Atlantic, and
southeast. A shortwave trough was moving through the broad trough
and extended from northwestern Ontario to Manitoba to the
Dakotas. Shortwave ridging extended from the Southern Plains to
portions of the Rockies. Meanwhile an upper level low was
meandering along the BC Coast with an associated trough south and
southwest across the eastern Pacific that was approaching the west
coast of the Conus. At the surface, an area of low pressure was
tracking across Quebec with a cold front/wavy frontal zone
extending to the eastern Great Lakes to mid MS Valley to near the
KS and OK border and then west northwest to eastern Co to the
Pacific northwest. A ridge of high pressure extended from off the
southeast coast into the Gulf. Another ridge extended into the
northern and central Plains behind the frontal zone. Locally in
the warm sector, temperatures have reached record highs at JKL and
LOZ with highs across the region in the upper 60s to

Tonight and Tuesday, the shortwave trough near the US/Canadian border
should rotate across Ontario and the Great Lakes and into Quebec
and then across the Northeast and mid Atlantic to the Maritimes
and off the Northeast US coast. The surface low should precede
this shortwave across Quebec and into the Maritimes and then into
the Atlantic. The trailing cold front will approach the OH Valley
this evening and then sag into the area overnight dropping to the
southeast portion of the area around dawn on Tuesday. This front
should continue sagging southeast on Tuesday stalling from the
Carolinas across the Gulf coast states to the TX panhandle and
then north near the front range of the Rockies and into the
northwest Conus. There will be limited moisture with this front
generally confined below 775 mb or 800 mb. Time height sections
generate some omega late tonight and on Tuesday morning within
this moist layer and the low level flow will become briefly
upslope behind the boundary.

Some light rain, sprinkles, or drizzle will be possible late
tonight and into Tuesday morning, with chances lingering longest
near the VA border in the Harlan and Letcher county vicinity to
midday or early afternoon. Pops in the 10 to 20 percent range
were used. Initial clear skies and slackening winds around or
after sunset may allow for sheltered eastern valleys to drop into
the mid to upper 40s during the evening, before clouds increase
and temperatures there rise with the mixiness associated with the
front. Temperatures will still be near normal for highs in the far
north and the 50s to low 60s south and above normal by 5 to 10
degrees or more there.

Tuesday night, a shortwave trough emerging from the southwest
Conus after moving out of the trough that will have neared the
west coast of the Conus will track into the Plains to Ozarks
vicinity with another trough behind it working across the Rockies
and nearing the Plains. Low pressure should continue to develop
in the TX to OK panhandle with the boundary extending into the
Southeast starting to lift north. Models have varying amounts of
moisture returning into eastern KY with some that only suggest
clouds while the higher resolution models like the NAM or HRRR
which have greater moisture depth and have some light QPF in
recent runs. Opted to keep pops around 10 percent in the
northwest and 20 for much of the area further south where some
guidance generated QPF. More substantial precipitation chances
will arrive early in the long term period. Temperatures on Tue
night should range from the mid 30s further north and east to the
low 40s southwest or on the order of 5 to 10 degrees above
normal.

.LONG TERM...(Wednesday through Monday)
Issued at 549 PM EST MON FEB 3 2025

Progressive and more zonal-like flow will control over the CONUS
through the end of the work week, before amplification takes place
this weekend and into early next week, as deeper and broader
troughing evolves to our west. The models are in good agreement
with the long wave pattern, but differ on the details of the
smaller-scale features. These differences become increasingly
important for the latter half of the extended, as we will be in an
active period weather-wise. For now, have continued with the
blended approach, while incorporating some of the 12z model
guidance trends.

Short wave ridging will start out aligned from south central
Canada through the middle Mississippi Valley, with a short wave
trough riding east northeast across the central/southern Rockies.
At the surface, arctic high pressure will be sprawled from Upstate
New York through the Great Lakes and into the Upper Midwest, while
a stationary frontal boundary is positioned from the Deep South
through southern Plains. Through the middle of the week, this
boundary will shift northeast as a warm front, as lee-side low
pressure spills across the middle Mississippi Valley/southern
Plains, and eventually the Ohio Valley. Showers, along with a few
rumbles of thunder at times, will overspread eastern Kentucky
from southwest to northeast, especially Wednesday night into
Thursday, when the better 850 mb moisture transport moves through
the area. Fortunately, the GFS, which had been the bullish model
has trended leaner on QPF during this time frame, with most
locations looking at around an inch, with locally higher amounts,
where any more convective bands occur. A cold front will sweep
through the area by Thursday night, bringing a temporary end to
the precipitation, with Friday looking like the only dry day.

This dryness will be short-lived, as potent short wave energy
makes its way onshore across the West Coast, and then traversed
east across the northern quarter of the CONUS. This will result
in more lee-side cyclogenesis, with deeper low pressure moving
from the southern Plains through the Ohio Valley on Saturday,
allowing for another progressive warm front and eventual cold
front to shift across eastern Kentucky. Another beefier shot of
associated moisture transport will bring another two thirds of an
inch to inch of rainfall to eastern Kentucky, keeping soils
saturated and renewing some good rises on area rivers by that
time, although this system does move through quickly, so the risk
of particularly excessive rainfall looks low right now. As colder
air moves in late Sunday night into early Monday morning, some of
the lingering lighter precipitation could change over to snow by
that time, although with the prolonged period of well above normal
temperatures preceding this, impacts look minimal at this point.

Beyond Monday, all eyes look toward how the next progressive
short wave trough evolves within broader west southwest flow
aloft upstream. This will dictate on whether we see a growing
threat of more significant hydro problems by that time or not.
Highs will peak on Thursday and Saturday, with readings in mid to
upper 60s, with cooler readings in the 40s and 50s following the
first cold frontal passage on Friday, and then mainly 40s
occurring on Monday proceeding the second cold frontal passage.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 624 PM EST MON FEB 3 2025

VFR conditions were reported at all airports to begin the
forecast period. A cold front approaches through the evening and
overnight, crossing KSYM beginning around 09z and the remainder of
terminals by ~13z. Winds to begin the period will again increase
aloft while surface winds decrease, resulting in LLWS between 00z
and just a few hours before frontal passage. As for clouds and any
potential precipitation, clouds at low levels will increase with
MVFR cigs forecast to develop around or shortly after 06Z in all
areas. MVFR cigs and areas of IFR cigs should then persist near
and behind the boundary through the end of the period, except in
more northern locations such as KSYM where clouds may begin to
scatter by ~17z. Along with the MVFR ceilings some patchy light
rain or drizzle will also be possible, but visibility reductions
below 6SM are not forecast at this time.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...CMC
SHORT TERM...JP
LONG TERM...JKL
AVIATION...CMC




Area Forecast Discussion

National Weather Service Pocatello ID

 106 PM MST Mon Feb 3 2025

.SHORT TERM...
The weather today is highly dependent on your location in eastern
Idaho. For folks in and near the central mountains, it`s more of
the same....LOTS OF SNOW! Further south and east, we`re seeing a
bit of a break in the precipitation and afternoon satellite
imagery even shows some breaks in cloud cover across the Magic
Valley and Snake Plain allowing for some blue sky to be seen.
Don`t get too excited, this won`t last but we`ll take what we can
get after prolonged precipitation and cloud cover. Let`s start
with the snow first. As expected, the axis of deeper moisture has
shifted to the north today allowing for precip (valley
rain/mountain snow) to cut off in the Magic Valley, Snake Plain
and gradually into the eastern highlands. The latter location will
likely see a few more hours of some light snow before all is set
and done but most of this will shut off shortly. As such, the
Winter Storm Warning will likely expire later this afternoon.
Don`t get too excited. The break in snow will be brief, more on
that below, but at least it`s something.

The same cannot be said across the central mountains however as
the  SW/NE oriented plume of moisture will continue into much of
the day tomorrow allowing for the relentless snowfall to continue.
As such, Winter Storm Warnings continue into Wednesday AM there
where copious additional amounts of snowfall can be expected.
Check out our latest Winter Weather headlines for specifics in
totals or check our latest expected, low-end, high-end, and
probabilistic forecast snow information at
weather.gov/pocatello/winter.

Outside of the central mountains, things will be mostly dry for
the next 24 hours or so with temperatures running above
climatological norms. Hi-res CAMs do show at least some potential
for a few stray showers across the Arco Desert, the Snake Plain
and eastern highlands but these will be more of the hit or miss
variety as opposed to the prolonged precip we saw throughout the
weekend. We could see temps reach 50 from around Pocatello south
and west into the Magic Valley tomorrow. Low to mid 40s elsewhere
so most areas will see rain with any precip but the highest
terrain would see snow showers. As we get into late Tuesday and
into Wednesday morning, deeper moisture again returns to much of
the region bringing another round of rain and snow for us all.
McKaughan

.LONG TERM...Wed through next Mon night
Clusters were only partially available at forecast time. Very
little difference among the cluster members concerning the upper
level trough that swings through during the upcoming weekend. And
Thu is also very similar among members with some westerly flow.

The moisture plume from the southwesterly-flow atmospheric river
continues into Wed night, when the flow becomes more zonal as a good
chunk of the low splits off and moves through the Pacific Northwest
and Canada. Thu looks like a brief break, but there is yet another
shortwave entering the Pacific upper level trough the re-invigorates
and by Thu night yet another moisture plume is feeding into the
northern Rockies. This lingers through Fri and Fri night, bringing
more rain and snow, and keeping temperatures mild for the time of
year. On Sat morning, this second shortwave has moved to the east
and a more prolonged northwesterly flow kicks in for the remainder
of this forecast period. The dominating low is now in central
Canada. This will mean colder air with lighter precipitation amounts
for Sat-Mon. And there is yet a third short wave trough expected,
that makes the precipitation threat possible each twelve hour period
during that time. Messick


&&

.AVIATION...03/18Z to 04/18Z
At least a brief break from IFR and airport closure is developing
for all 5 TAFs. However, it is uncertain just when precipitation
may redevelop. HRRR guidance is indicating a return to rain and
snow during the middle of tonight, while blended guidance predicts
a nearly dry overnight, with the exception of KSUN where after
04/06Z there should be a return of mostly SN with some RA
possible. By the return of operations tomorrow morning, around
04/14Z, precipitation has returned. Or at least the threat of
precipitation, to the other 4 airdromes. KSUN and KDIJ are the
most affected with at least marginal VFR expected. Messick

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 5 PM MST this afternoon for
IDZ064>066.

Winter Storm Warning until 5 AM MST Wednesday for IDZ071>075.

&&

$$