Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/27/22

Area Forecast Discussion...UPDATED

National Weather Service Cheyenne WY

 814 PM MDT Wed Oct 26 2022

.UPDATE...
Issued at 759 PM MDT Wed Oct 26 2022

Updated forecast for tonight and Thursday morning to increase POP
and QPF across mainly the I-80 corridor from Elk Mountain to
Cheyenne. Models and this afternoon`s ensembles are trending a
little more aggressive on the potential for some light snowfall
tonight across southeast Wyoming. 700mb low pressure feature is
expected to develop along the Front Range late tonight and drift
slowly southeast...which should result in some additional
convergence along the Front Range and adjacent plains. In
addition, A few hours of WAA aloft around the 650 to 700mb layer
should result in enough moisture advection to increase snowfall
probabilities along the I-80 corridor after midnight. HRRR
guidance agrees with this outcome between 06z and 18z Thursday,
and has verified well so far today with the activity further west.
Would not be surprised to see 1-2 inches of snow accumulation by
9 am Thursday for Laramie, Arlington, the I-80 Summit, and near
Cheyenne based on current trends. Increased snow totals
tonight/early Thursday, but not nearly as high as the ensemble
guidance suggests yet due to limited confidence with virga and how
much dry air remains in the residual boundary layer. Updates have
been sent.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 215 PM MDT Wed Oct 26 2022

A low was located over central ID with a trough axis trailing south
into NV. The bulk of the energy and QG lift was located over southern
ID and northern NV/UT with convective activity increasing and even
a couple lightning strikes. Well ahead of this feature, light showers
were developing across southern WY. Rain and snow showers will continue
to increase in coverage from west to east through the rest of the
afternoon. There will be periods of moderate snowfall for the Snowy
and Sierra Madre mountains this afternoon and evening, with 2 to 4
inches expected, with heavier snow falling south of the WY/CO border
along the track of the mid level low. The showers will taper off from
NW to SE Thursday morning, with skies clearing. It will continue cooler
than normal with 700mb temperatures from -4C to -8C. Clear skies and
lighter winds Thursday night will result in low temperatures in
the upper teens to upper 20s. The warming trend commences Friday as
700mb temperatures rise to 2C to 6C in the afternoon. Expect high
temperatures in the mid 50s to mid 60s along and east of I-25, with
40s to lower 50s west. Lows Friday night will be milder with lower
20s to mid 30s.

.LONG TERM...(Saturday through Wednesday)
Issued at 215 PM MDT Wed Oct 26 2022

Fairly quiet weather over the weekend will likely turn more active
for the latter part of the long term forecast period next week. The
main concerns are the potential for strong winds on Monday and the
next possible precipitation event on Wednesday. Uncertainty remains
quite high for both of these.

The synoptic pattern over the weekend will be largely under a zonal
flow regime. A cutoff low, which will be spawned by the system
moving through our area today, will be sitting over the southern
plains, while a few weak shortwaves will perturb the flow slightly
over the western US. An elongated area of 500-mb vorticity is expected
to pass through on Saturday, which will likely increase mid to high
level cloud cover. 700-mb temperatures will hover around 0C, leading
towards near normal temperatures. Another shortwave right on the tail
of this pushes through early Sunday and may knock another degree or
two C off the 700-mb temps, so expecting slightly cooler temperatures
Sunday afternoon. This period looks dry with limited lift, so
precipitation is unlikely.

A strong jet stream slamming into British Columbia over the weekend
will start to sag southward on Monday, bringing the temperature
gradient and storm track closer to our area. A week surface low
spinning up over the Canadian prairie at the nose of the jet aloft
will lead to falling MSLP over the high plains and increase the
cross-barrier MSLP gradient, though this isn`t too impressive now
based on current forecasts. Similarly, jet shifting southward will
increase height gradients to near typical high wind thresholds. The
GFS shows 700-mb winds around 40-45 knots on Monday, pointing to a
the possibility for a strong wind event for the wind prone areas.
Will need to watch this period to see how this unfolds, but it looks
marginal for reaching high wind criteria. For Tuesday, the zonal
flow starts to transition more towards western troughing as a longer
wave digs southward. Models show the flow aloft turning southwesterly
with good warm-air advection and downsloping leading to climbing
700-mb temperatures to around +2 to +4C.

Ensemble spread is fairly tight through about Tuesday. Little
variability between member forecast temperatures projects higher
confidence in the general temperature forecast, but this changes
dramatically on Wednesday. For example, the GEFS 10th to 90th
percentile 700-mb temperature spread at 00z Wednesday is about 3C,
but this increases to about 12C by 00z Thursday. This indicates a
major drop in forecast confidence. The deterministic GFS shows a
deep and impressively strong upper level trough digging into the
Great Basin, leading towards lee-cyclogenesis over the high plains.
This specific solution ejects the trough quickly, keeping much of
the precip along and west of the Laramie range, but still would
bring some light QPF to the east. The deterministic ECMWF is vastly
different, showing a shallow, progressive trough sliding through
around this time. This keeps most of the precip to our north, but
does allow some light QPF west of the Laramie range. Most of the
ensemble members are somewhere in between these two extremes. For
now, keeping the official forecast near the NBM 50th percentile for
temperatures, with PoPs for most of the area, but highest west of
the Laramie range.

&&

.AVIATION...(For the 00Z TAFS through Thursday evening)
Issued at 535 PM MDT Wed Oct 26 2022

A potent upper level trough will dig southeast across western and
southern Wyoming tonight and will result in cloudy skies and an
increasing threat for locally heavy snow showers until midnight
(06z). Snowfall will then increase in coverage after 06z with light
to moderate snow possible along the I-80 corridor terminals.
Snowfall may linger through 15z early Thursday morning before skies
gradually clear from west to east.

HAZARDS/WEATHER TRENDS: Will continue with prevailing VFR conditions
tonight for all terminals.  However, scattered to numerous snow
showers this evening through 05z will result in brief IFR conditions
in VIS below 1 mile and CIGS around 500 feet for mainly KLAR and
KRWL. Snow will become lighter after 06z but should become more
widespread further east, impacting KCYS and possibly KSNY with
periods of IFR conditions through 15z Thursday.  Kept VCSH in the
TAFs for now but will likely update later with increasing
confidence.

&&

.FIRE WEATHER...
Issued at 215 PM MDT Wed Oct 26 2022

A upper level disturbance will move east across Colorado tonight and
Thursday morning. Rain and snow showers will develop this afternoon
and become all snow tonight before tapering off Thursday morning. Snow
accumulations of 2 to 4 inches are likely through tonight over higher
elevations west of the Laramie Range. Temperatures will remain cool
Thursday, followed by a warming trend Friday through early next week.
Afternoon relative humidities of 30 to 40 percent Thursday will lower
to 15 to 25 percent Friday and Saturday. Gusty winds at that time will
elevate fire weather concerns along and east of the Laramie Range.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

$$

UPDATE...TJT
SHORT TERM...MAJ
LONG TERM...MN
AVIATION...TJT
FIRE WEATHER...MAJ



Area Forecast Discussion

National Weather Service Grand Forks ND

 611 PM CDT Wed Oct 26 2022

.UPDATE...
Issued at 610 PM CDT Wed Oct 26 2022

A tranquil evening is expected across the FA, with light winds and
only a small amount of cloud cover. These clouds will continue to
increase late tonight into Thursday, but mainly south of a line
from Valley City to Bemidji. Made some minor sky cover
adjustments, otherwise the forecast is in good shape.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 300 PM CDT Wed Oct 26 2022

Forecast challenges will be if we get any precip in our southern
counties tonight, along with temperatures throughout the period.

Water vapor shows split flow aloft with the cut off upper low
spinning over the Intermountain West. This cut off will stay well
to our south tonight and tomorrow morning, but a weak
lead/northern branch shortwave will be moving through SD/Nebraska
area. This weak system could bring a few light rain showers to
our southern counties, with the formally drier HRRR run now
showing some decent returns into west central MN. Any amounts
reaching the ground will be very light, and with all rain expected
impacts will be negligible. Further north, skies will have less
cloud cover tonight and southwest winds could bring some patchy
fog from northwestern and north central ND into our area. SREF
probabilities have around 40 percent chance of less than a mile
visibility for our northwestern counties, so will continue to keep
a patchy fog mention going.

South to southwesterly surface winds providing warm air advection
and good mixing should help boost temperatures into the mid 50s
tomorrow, with some slightly cooler temps in west central MN where
clouds will hang on longer. Southwesterly surface winds will
continue into Thursday night and should help keep temps above
freezing even with decreasing clouds.

.LONG TERM...(Friday through Wednesday)
Issued at 300 PM CDT Wed Oct 26 2022

Overview...

The long term period looks to remain on the quiet side, with
precipitation chances increasing toward late next week. Otherwise,
seasonably mild weather is expected to persist from the weekend into
early next week as well.

Discussion...

The upper level flow pattern looks to be unwavering through the
weekend with split flow over the CONUS resulting in generally zonal
flow over the northern Plains. A transient period of upper level
ridging is expected on Friday ahead of this as a trough closes off
over the southern CONUS. This will result in what looks to be the
warmest day of the extended period on Friday, with widespread highs
in the upper 50s to low 60s. The weekend will then feature a
continuation of quiet weather as zonal flow sets up aloft. This flow
pattern looks to persist into early next week. High temperatures
look to fall a few degrees from Fridays high temperatures, but are
still expected to remain well above normal for this time of year,
generally in the 50s, with a few low 60s possible across the
southern FA.

Tuesday is when global consensus begins to introduce a shift in the
upper level pattern. As large scale troughing builds in over the
western CONUS, southwesterly flow aloft is expected to set up over
the northern Plains. Despite this, quiet weather is anticipated on
Tuesday, with high temperatures once again firmly in the 50s.

Beyond Tuesday, there are signals within ensemble guidance
indicating that the longwave trough building in over the western
CONUS will eventually travel eastward. Ensemble cluster analysis is
largely in good agreement on the progression of this feature, with
some discrepancies on exact location and timing. There are still a
lot of questions surrounding the progression of the wave, however,
as well as any precipitation potential, timing, and location at this
time. While far from a guarantee, given prominent signals within
ensemble guidance, it would be remiss to not at least mention the
possibility for increasingly active weather toward the middle/end of
next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 610 PM CDT Wed Oct 26 2022

No big impacts are expected for this TAF period. South winds will
pick up Thursday morning, and be fairly breezy through the
afternoon. Some BKN040-060 ceilings look to affect KFAR and KBJI
late Thursday morning and afternoon. There may also be a few light
showers around, but overall confidence in that is pretty low, so
did not mention any at this time.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

$$

UPDATE...Godon
SHORT TERM...JR
LONG TERM...Rick
AVIATION...Godon



Area Forecast Discussion

National Weather Service Chicago/Romeoville, IL

 924 PM CDT Wed Oct 26 2022

.UPDATE...
Issued at 924 PM CDT Wed Oct 26 2022

The forecast is in good shape with few changes needed this evening.

A recent hand analysis of the surface pressure, dew point, and wind
fields reveals an expansive 1020mb surface high pressure system
sliding across the Mississippi River Valley into Wisconsin.
Meanwhile, composite RGB GOES-16 imagery depicts an eastward-moving
cirrus shield associated with a weakening upper-level wave
approaching western Illinois within quasi-zonal flow aloft. With the
resident dry airmass in place (characterized by surface dew points
in the lower 30s and mean 850-500 RH in the neighborhood of 5%),
temperatures will continue to drop steadily over the next few hours
before upper-level clouds "dampen" the party and slow the fall.
Overnight lows still look good to hit the low to mid 30s, save for
the core of Chicago where the urban heat island will hold
temperatures in the lower 40s. Fog development overnight will be
contingent on any holes in the clouds that develop or westward
erosion of the upper-level clouds toward sunset (as hinted within
recent HREF guidance). For now, we will hold off on any formal fog
mention in the gridded database in favor of watching trends.

Updated products have been sent.

Borchardt/KK

&&

.SHORT TERM...
Issued at 220 PM CDT Wed Oct 26 2022

Through Thursday night...

The forest in the short term remains relatively quiet thanks to a
large area of surface high pressure that will drive most of our
weather for the next couple of days. A tight pressure gradient ahead
of the high pressure center has resulted in some breezy conditions
this afternoon. This will only last into this evening before the
pressure gradient weakens and we stop mixing into the enhanced flow
aloft for the night. Mostly clear conditions will hold on through
the night causing temperatures to cool to near or just above
freezing for most by early Thursday morning with the help of some
very light winds overnight. The clear skies and light winds are also
expected to result in some areas of fog overnight. Guidance insists
that the fog shouldn`t be widespread, yet models are having a hard
time agreeing on where to place the most favorable areas for fog to
develop. However, the RAP has liked the Illinois River valley all
day long and the HRRR is trending toward the same idea.

Heading into Thursday, we should begin the day with lots of blue
sky. However, after the center of high pressure moves to our east
Thursday morning, the return flow will introduce some mostly cloudy
conditions for the latter half of the day. Despite the clouds, no
rain is expected through the day on Thursday. Temperatures will be
similar to today with highs in the mid-50`s. The added cloud cover
is one factor that will keep temperatures a bit warmer Thursday
night than tonight. Lows early Friday are forecast in the middle and
upper 30`s.

Doom

&&

.LONG TERM...
Issued at 220 PM CDT Wed Oct 26 2022

Friday through Wednesday...

There are no noteworthy weather impact concerns through mid next
week. A rather tranquil pattern is in store, with seasonably mild
daytime temperatures. Friday and Saturday will be quiet under the
influence of surface high pressure centered over the eastern
Great Lakes and Northeast. Forecast highs are in the upper 50s-low
60s Friday, followed by seasonably chilly mid-upper 30s lows
Friday night outside of Chicago (40-45 in/near the city). Modest
warm advection aloft amidst rising heights will support highs
reaching pleasant low-mid 60s on Saturday (except slightly cooler
IL shore) for a nice start to Halloween weekend.

The main feature of interest for sensible weather effects is a
mid-upper short-wave tracking from the northern Rockies to New
Mexico by later Thursday. This short-wave will become a closed
low cut off from the primary upper jet displaced well to the
north, resulting in it meandering eastward across Texas Friday
into Saturday. It will then become an open wave as it lifts north
from the lower and mid MS Valley to the Great Lakes Sunday into
Monday. The weakening nature of large scale forcing should tend to
result in a more disjointed precip shield with northward extent,
and relatively higher shower coverage Sunday PM for the southeast
half or so of the CWA, where chance PoPs appear reasonable.
Mostly cloudy skies will keep temps a bit cooler, in the upper
50s-lower 60s.

Another weaker short-wave lifting northeastward across the region
may keep the spotty shower threat into Monday/Halloween for the
southeast half or third of the CWA, mainly in the morning. With
the exception of slower guidance, current signs point toward
favorable trick or treating conditions for most of it not the
entire area, with highs in the upper 50s-lower 60s and temps by
7PM in the lower-mid 50s. In the wake of the weak systems Sunday-
Monday, prevailing south-southwesterly flow and warm advection
will yield highs in the mid-upper 60s Tuesday-Wednesday along with
above normal overnight lows. Some precip chances may return just
beyond day 7 from troughiness in the west.

Castro

&&

.AVIATION...
For the 00Z TAFs...

There are currently no significant aviation weather concerns over
the TAF period. Light northwesterly winds will trend essentially
light and variable this evening and overnight, and may
occasionally acquire a NE direction at the Chicago-area terminals.
Winds will likely remain under 7 kts. There is a small potential
for some patchy BR development overnight, mainly in the vicinity
of river valleys. The main limiting factor tonight appears to be
from an incoming area of mid and high-level cloud cover which will
thicken up through the late evening hours. As a result, have left
BR out of all the TAF sites, but will keep an eye on GYY and DPA,
however.

Eventually, winds will come around of the east or east-southeast
through Thursday morning where they will remain through the rest
of the TAF periods.

Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&

$$

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Area Forecast Discussion

National Weather Service Lubbock TX

 641 PM CDT Wed Oct 26 2022

...New AVIATION...

.SHORT TERM...
(This evening through Thursday)
Issued at 217 PM CDT Wed Oct 26 2022

A surface low over southeastern Colorado will keep winds mostly
out of a southerly direction this evening and much of the night.
The surface low will migrate southward across northeastern New
Mexico into the far northwestern Texas Panhandle/western Oklahoma
Panhandle by mid morning in response to what will be an
approaching upper low. The upper shortwave that will eventually
become the upper low is currently over Idaho and is expected to
push southeastward towards Colorado/Wyoming and become a closed
low by 12Z tomorrow. The low will then deepen slightly as it
reaches Farmington, New Mexico by 18Z. Models have a general
consensus of having the low over Cline`s Corner by 00Z tomorrow
evening. The speed and location of the low will be one factor in
helping or hindering the possibility for convection along the
dryline before 00Z tomorrow evening. Currently models are
relatively dry before 00Z with the exception of higher res models
such as the 12Z HRRR and 00Z NSSL FV3. The HRRR mostly keeps
precip in the form of virga showers pre-00Z with convection
developing along the dryline east of the Caprock at 00Z. The FV3
is the most bullish in terms of afternoon precip with virga
showers developing by 18Z behind the dryline with coverage
increasing just before 00Z as the cold front moves into the
region. A mention of slight chance of showers and thunderstorms
has been introduced across much of the FA for late tomorrow
afternoon as enough mid/upper level lift should be present for the
development of at least virga showers with a rumble or two of
thunder. The overall main threat from any storm that does develop
will be wind gusts up to 60 mph.

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 217 PM CDT Wed Oct 26 2022

Isolated to scattered showers and thunderstorms ongoing to begin
Thursday evening should quickly expand in coverage as the upper low
over central New Mexico moves southeastward toward Hobbs by
midnight. Increasing vertical motion and cooling mid level
temperatures eroding lingering convective cap will see an expansion
of storms along the dryline across the eastern third of the forecast
area as well as increasing high-based and elevated convection in the
dry air west of the dryline and north of a southward-moving cold
front. There remains a narrow window for marginally severe
thunderstorms along the dryline early in the evening with progged
surface-based CAPE of 1250-1750 J/kg across the Rolling Plains at
00Z. Precipitation in the form of rain will wrap-around the low as
continues its march to the east-southeast late Thursday night
through Friday with likely to categorical PoPs justified between
midnight and noon before slowly tapering off Friday afternoon to
early evening. The post-storm period from Saturday through the end
of the forecast period will see slowly moderating temperatures as
heights and thicknesses increase slowly underneath a continuation of
generally cyclonic mid to upper level flow.

&&

.AVIATION...
(00Z TAFS)
Issued at 636 PM CDT Wed Oct 26 2022

VFR conditions will continue through the majority of this TAF
period. Winds roughly 800 ft AGL will increase overnight leading
to LLWS at all three TAF sites tonight through Thursday morning.
Tomorrow afternoon, southwesterly surface winds will become
breezy and towards the end of the TAF period showers and
thunderstorms should be developing. However, confidence on a
direct impact to a TAF site remains too low at this time to
include a mention in the TAF but KCDS and KPVW will be the most
likely sites to see any activity.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...51
LONG TERM....07
AVIATION...58



Area Forecast Discussion

National Weather Service Twin Cities/Chanhassen MN

 648 PM CDT Wed Oct 26 2022

.DISCUSSION...(This evening through Wednesday)
Issued at 229 PM CDT Wed Oct 26 2022

Key Messages:

- Chance for showers in western Minnesota tomorrow morning, weakening
  by the middle of the day. Cloudy for much of the area tomorrow.

- Quiet and dry weather return after Thursday and continue through
  the weekend, with above normal temperatures through at least the
  middle of next week.

Tonight and Thursday...
Now that a few of the CAMs have begun to resolve the precipitation
potential for western Minnesota tomorrow, the signal for rainfall is
a bit stronger than 24 hours ago. The HRRR has a decent amount of
scattered showers making it as far east as the western Twin Cities
Metro around sunrise tomorrow, with stronger showers mainly confined
to southwestern Minnesota. These showers will form along the nose of
a weak low level jet, with low to mid level moisture and WAA
resulting in the showers. As we head into daylight, this jet will
weaken and cut off both the lift and moisture, thus the showers
should dissipate fairly quickly once we reach the middle of the day
and afternoon. For those that do not see rain, we will end up being
cloudier than it has been over the past few days and cloudier than it
will be as we head into the weekend, with clearing gradually through
late Thursday into Friday.

Friday through Wednesday...
Upper level flow returns to primarily zonal over our coverage area,
with a cut off system remaining far to our south and primarily
affecting the southernmost states. This likely will keep any further
precipitation chances through the period to a minimum, with weak
surface high pressure lingering in the northern plains as we remain
moisture starved. Temperatures under this scheme will remain above
normal in the mid 50s to low 60s for highs compared to normals around
50 this late in October. It is looking to be a great day for
Halloween on Monday, with high temperatures in the upper 50s to mid
60s under mostly sunny skies which will linger into the evening. Our
nights will continue remain above freezing, dropping into the upper
30s to low 40s. Precipitation chances will remain absent with a lack
of both forcing and moisture, however this could change as we head
towards the end of next week. A few long-range models and ensembles
are beginning to show potential for a pattern shift, with a more
active upper level pattern aiding in guiding a more dynamic surface
regime to the area. This is still in the 200-240 hour time frame and
thus heavily subject to change.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 619 PM CDT Wed Oct 26 2022

Light rain in Nebraska will continue to move northeast this evening,
bring light rain to western MN Thursday morning. Expect some wet
surfaces in RWF and AXN and possibly STC into early Thursday
afternoon, when this rain is expected to dry up with the forcing.
Despite the rain, expect VFR cigs to remain, with cig heights
ranging from as low as 5k feet in western MN, up to around 15k feet
in western WI. For winds, as the high continues to slide into MI,
we`ll continue to see southeast winds become established overnight,
that will become southerly on Thursday, with speeds slowly bumping up
toward 10 kts.

KMSP...A few sprinkles can`t be ruled out Thursday morning, but the
chances aren`t high enough to include in the TAF. Otherwise,
confidence is once again in the TAF this period.

/OUTLOOK FOR KMSP/
FRI...VFR. Wind SW 10-15 kts.
SAT...VFR. Wind SW 5-10 kts.
SUN...VFR. Wind W 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&

$$

DISCUSSION...TDH
AVIATION...MPG



Area Forecast Discussion

National Weather Service Pocatello ID

 201 PM MDT Wed Oct 26 2022

.SHORT TERM...Today through Thursday. The cold front is just
about all the way through the eastern highlands this afternoon and
cooler air is moving in now along with our gusty winds. The band
of precip with the front was our main push of snow with this
system, but snow showers will still continue on and off through
the afternoon and evening, especially up on the mountains. The NAM
and HRRR and both picking up on a convergence band of snow
developing between Arco and Idaho Falls around 3-4PM and moving
southeast before fizzling out around 10PM. The biggest impact from
this would be reduced visibility for anyone traveling on I-15
between 6-9PM. At the same time, the wind will be starting to back
off which will decrease snow squall potential. With this quick
burst of snow, up to about an inch is possible. The WSUP NBM 4.1
is showing a 60-70 percent chance of over a tenth of an inch of
snow between Pocatello and Idaho Falls by midnight. However, it
only shows about a 5 percent chance of at least an inch.
Precipitation looks to wrap up by midnight across the entire area
and the highest snow totals by the end of this event are still
expected to be up in the mountains. Event totals in the Sawtooths
will be up to about 7 inches of snow, 4-6 inches in the Bear River
Range, 3-6 inches in the Big Holes, and about 2-4 inches for the
rest of our mountains. The wind will still be blowing into the
evening, too, with sustained winds between 20-30mph and gusts
between 35-45mph. The strongest gusts will be in the South Hills
and up through the Arco Desert and Snake Plain. Winds begin to
back off around 8-9PM. Thanks to lighter winds overnight and
moisture from today, patchy valley fog is expected to develop
after midnight and continue through 8AM. Overall, Thursday will be
a much quieter weather day in comparison as ridging builds back
in to the area. Some afternoon sunshine will help warm most of the
area back into the low to mid 40s, which is still well below
average for this time of the year. AMM

.LONG TERM...Friday through Wednesday. Upper ridge remains in place
Friday, then starts to flatten Saturday with passage of dry
shortwave feature. Temperatures cool slightly in association with
this feature. Models continue to trend slower with onset of
precipitation associated with approaching Pacific trough.
Ensemble clusters for Sunday favor generally a flat flow across
the entirety of the Pacific northwest and northern Rockies. NBM
introduces weak precipitation chances across portions of the
central mountains Sunday night, spreading the moisture across the
rest of East Idaho on Monday through the base of shallow active
trough sliding inland along the Canada border. Flow remains nearly
zonal and unsettled behind this feature and ahead of next
incoming Pacific trough. Only edits to the extended period were to
nudge winds higher for Monday- Wednesday in response to guidance
trends. DMH


&&

.AVIATION...Cold front with attendant precipitation band has pushed almost
completely through East Idaho early this afternoon, with showers
developing in wrap-around air mass. Ceilings remain generally
VFR/MVFR outside of the precipitation but IFR/LFR within the band
and stronger showers. Winds remain gusty especially in clear
pockets where deepest mixing can be realized. Showers and gusty
winds continue into early evening, then second consolidated band
of showers works out of central mountains through the Snake Plain
for another round of snow. For the remainder of the night into
early Thursday, expect gradual clearing with weakening winds.
Skies should improve back to VFR most areas, though lower
elevation areas could see stratus/fog development with IFR
conditions. KDIJ would be the most likely location for this to
occur overnight. DMH


&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$



Area Forecast Discussion

National Weather Service Raleigh NC

 1043 PM EDT Wed Oct 26 2022

.SYNOPSIS...
A weak cold front will move across the Carolinas tonight. High
pressure will extend into the region on Thursday and persist into
Saturday. The next storm system may bring unsettled weather to the
area later Sunday into Monday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 1040 PM Wednesday...

Just issued a DFA for portions of the northeast Piedmont and Coastal
Plain of central NC through 6 AM, as more obs are reporting a
quarter mile or less. Still think the threat for dense fog will only
be for a couple of hours for most locations, but could lingering
across portions of the coastal plain if the front hangs up.


Previous discussion... As of 1015 PM Wednesday

A weak band of showers associated with a cold front moving through
central NC this evening has shifted to the east of the area.
However, the main cold front and CAA continues to slowly move
through/filter into the area this evening, with the main front as of
10 PM located across the northwest Piedmont and is denoted by a
northwesterly wind shift and dewpoints falling into the 40s. With
clearing skies and calm winds ahead of the front, we are seeing some
fog develop in advance of the front, especially across the northeast
Piedmont and Coastal Plain including some patchy dense fog. Will
need to monitor obs for a possible short lived DFA. Expect visbys
should improve within the next few hours for most locations (by
06Z). However, the latest few runs of the HRRR show the potential
for the front to hang up across our far east, with a lingering
threat for fog until around 12Z when a push of drier air from the
north will send the front to the south of the area. Low temps are
expected to range from the upper 40s northwest to the mid 50s
southeast.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
As of 245 PM Wednesday...

Central NC will be situated between a split flow regime with the
polar jet situated over the Northeast into the Great Lakes region,
while the subtropical jet weakly ridges into the lower MS Valley and
extending southeast into FL. Farther west, a phasing between the two
jets will be underway as a deep positively tilted trough dives into
the Four Corners region by Thursday morning. As subtropical riding
builds into the Southeast, immediately downstream of the amplifying
trough, a 70-100kt jet streak will move into Lower MS Valley
extending into the TN/OH Valley and direct upper level moisture into
southern Mid-Atlantic Thursday night into early Friday morning. At
the surface, the cold front should be pushed through central NC by
Thursday morning with much drier air in place (15 degrees lower) as
strong high pressure will begin to build into the Great Lakes region
and strengthen through the day, as it migrates eastward over the
Northeast by Friday morning and nose down through the southern Mid-
Atlantic into the Southeast.

Skies should be partly cloudy to mostly clear (from SE to NW) during
the morning hours with fair weather cumulus developing under very
dry/stable thermodynamic profiles above 850mb during the afternoon
hours. Cool northerly winds will usher in near normal temperatures
ranging from mid 60s to low 70s for highs and falling into the 40s
Thursday night into early Friday morning.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 245 PM Wednesday...

Focus shifts to the west as a closed low develops over the southern
Plains by Friday morning. Ensemble guidance continues to show a
clear split in solutions between the EPS and the GEFS/CMCE. The
latter shows a quicker eastward progression by Sunday evening while
the former favors a slower solution as the closed low briefly
becomes detached from the northern stream flow. How far this system
can migrate east by Sunday night before being picked up by the next
shortwave will have implications on timing/longevity of potential
precipitation this weekend into early next week. Given the nature of
the pattern and potential cutoff nature of the southern stream low,
will opt with the slower Euro and its ensemble members for late this
weekend into early next week.

This solution results in a surface low in the vicinity of Arkansas
Sunday morning that will lift to the northeast and into Great Lakes
region by Monday morning. Strengthening flow and WAA at 850mb will
be directed over the western Piedmont Sunday into Monday morning
with likely a lull Monday afternoon then increasing again as a
cold/occluded front pushes moisture eastward Monday night into
Tuesday morning. Unfortunately, this timing will likely coincide
with trick-or-treating activities, but confidence on this solution
is medium/low given timing differences with upper level pattern as
noted above.

As for temperatures in the extended, high pressure wedging down the
southern Appalachians will set up a CAD regime and will favor below
normal highs through Sunday warming up to 5 degrees above normal by
early next week. Lows should favor above normal conditions through
early next week (up to 10-15 degrees above normal by Monday).

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
As of 800 PM Wednesday...

24-hour TAF period: A cold front will continue to move across
central NC this evening and reach the coast late tonight.
Persistent low level moisture is present ahead of the front
resulting in lingering patches of mainly VFR stratus and
stratocumulus clouds. In addition, some areas of MVFR fog will
continue to develop across the northern Piedmont and northern
Coastal Plain for a brief period this evening into the early
overnight potentially impacting the KRWI terminal and possibly
KRDU with a brief period of fog. As drier air moves into the
region behind the front, expect the fog to dissipate and any
lower stratus to lift a bit. Mainly VFR conditions are expected
on Thursday with SCT to occasionally BKN stratocumulus clouds
with bases of 3-5kft. Light west to northwest winds this evening
will become northerly overnight at 5 to 10kts and then north to
northeasterly at 7 to 12kts on Thursday.

Outlook: High pressure will extend into the region on Thursday
and persist into the first part of the weekend. Generally fair
weather is expected through Saturday although the moist
northeast flow could result in some CIG restrictions across the
east on Friday and especially Saturday. A storm system will
approach and move across the area Sunday into Monday resulting a
chance of adverse aviation conditions in clouds and showers.
-Blaes
&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 6 AM EDT Thursday for NCZ007>011-024>028-
040>043-076>078.

&&

$$
SYNOPSIS...BSD/Blaes
NEAR TERM...BSD
SHORT TERM...AS
LONG TERM...AS
AVIATION...Blaes