Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/06/21
Area Forecast Discussion
National Weather Service Boise ID
937 PM MDT Fri Nov 5 2021
.DISCUSSION...Locally gusty winds this evening as strong southwest
flow mixes to the surface. Weather radar is detecting 70kt winds
around 10kft MSL over southeast Oregon, feeding into the Owyhee
and Boise mountains. Evidence of this can can be seen in IR
satellite pics as well, with a clear cirrus band downstream of the
Owyhees. Precipitation aloft is bringing winds to the surface
with local gusts to 45 mph at lower valley locations and speeds to
55 mph at higher elevations. High resolution HRRR model picking
up on current wind pattern and have updated wind forecast closer
to this solution. With dry surface layer, seeing mostly virga or
sprinkles in valleys with light precipitation at higher
elevations. Winds will remain gusty overnight with the core of
strongest winds slowly shifting southeastward. Best chance for
measurable precipitation will remain in the mountains.
.AVIATION...Generally VFR, except areas of MVFR in rain and snow
showers north of KBNO KBOI, becoming isolated after 15z/Sat.
Mountains obscured. Snow levels 6500-7500ft MSL. Rain and snow
becoming widespread across the region after 00z/Sun with snow
levels near 6000ft MSL. Low level wind shear through 18z/Sat with
strong southwest winds off the surface. Surface winds: SW-SE
10-20kt, local gusts up to 40kt through 06z/Sat due to virga.
Winds aloft at 10kft MSL: SW 35-45kt.
.Sunday Outlook...Generally VFR, except areas of MVFR to IFR in
southern ID on Sunday morning. Clearing during afternoon with light
surface winds during the afternoon.
SHORT TERM...Tonight through Sunday night...Showers will enter
the region mainly over higher terrain this evening as a weak cold
front crosses the area. Gusty winds will also accompany the front
into the late evening as temperatures return to near seasonal
values. Showers will continue overnight ahead of another surge of
moisture on Saturday afternoon, which will bring another round of
breezy winds and widespread precipitation. Precipitation will
taper off on Sunday morning with temperatures lowering to several
degrees below normal. Snow levels will start off near 6000-7000 ft
MSL tonight, lowering to 4500-5500 ft on Saturday and 3000-4000
ft by Sunday afternoon. Roughly 2 to 5 inches of snow accumulation
is expected in the West Central and Boise Mountains through
Sunday, with elevations above 7000 ft seeing up to 7 to 9 inches.
The Upper Treasure and Magic Valleys will see around 0.1 to 0.2
inches of rain on Sunday, with lower valleys to the west seeing
light rain amounts.
LONG TERM...Monday through Friday...An upper level trough will
move north of our region Sunday night, bringing colder temperatures
and high level clouds through Monday afternoon. A deeper long wave
trough will pass through our region Tuesday morning, bringing
widespread valley rain and higher elevation snow showers to the
region. Snow levels will remain around 4000-5000 feet MSL through
Tuesday afternoon and will rise to around 6000-7000 feet MSL on
Wednesday. Northwest flow will dominate as the trough pushes east on
Wednesday night into Thursday night. As the ridge builds into the
coast, southeast Oregon and southwest Idaho will see light
precipitation associated with a warm front in a Pacific low pressure
system. The precipitation should clear by early Friday morning,
bringing warmer temperatures and a few mid level clouds for the
weekend. Valley regions could see fog and mid-level stratus building
in below a temperature inversion.
PREV SHORT TERM...AL
PREV LONG TERM....SA
Area Forecast Discussion
National Weather Service Charleston SC
1043 PM EDT Fri Nov 5 2021
A coastal storm will bring unsettled weather to our area
through Saturday night. High pressure will then build into the
region next week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A quick update to remove the headline to the Coastal Flood
Advisory for this evening. Otherwise, the forecast will continue
to feature nearly steady temperatures in the 40s, gusty NE
winds, and wet conditions for the rest of the night.
00Z KCHS sounding observed strong NE winds below 950 mbs this
evening. These winds will likely strengthen as a coastal low
deepens off the coast of the Southeast U.S. this evening and
overnight. In addition, the sfc pressure gradient between the
coastal low and ridging high pressure over the western Carolinas
should result in gusty NNE winds across the forecast area
tonight. No changes planned for the placement and timing of the
Wind Advisory and Lake Wind Advisory. Temperatures should remain
generally steady tonight, with periods of cooling during
The heaviest rains will likely occur over the coastal waters
and near the immediate coast late tonight and early Saturday
morning. Average rainfall through the night is forecast to be
0.25-0.75 inches, though it`s worth noting some probabilistic
guidance such as the HREF indicates there could be higher
amounts especially along the southeast Georgia coast.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Saturday: The mid-levels will consist of a strengthening/amplifying
trough and a closed low within it that`ll be moving over the
Southeast. At the surface, strong High pressure over the
northeastern U.S. in the morning will trend offshore with time.
Meanwhile, a strong storm will continue to trend to the northeast
with time, paralleling our coast. The storm is expected to start
moving away from our area overnight. Models still have a deep plume
of moisture on the eastern half of the storm. In fact, PWATs
exceeding 1.5" appear to be right along or just off our coast. These
values are well above normal for this time of year. All of the
models remain in great agreement showing a large area of showers
with this coastal storm. They have come into better agreement
regarding the location and timing of the widespread/heavier showers
and the timing. We don`t have the time to break down these details
in this discussion, but the general trend has been wetter. For this
reason, we raised both the POPs and the QPF. The highest QPF remains
along the immediate coast, tapering as one heads inland. The worst
conditions are expected Saturday morning. Winds will be very gusty,
especially along the immediate coast. We have Wind Advisories in
effect for some locations along with a Lake Wind Advisory for
Moultrie. Conditions will improve from southwest to northeast
overnight as the coastal storm moves away and high pressure starts
to build from the west. It`s entirely reasonable our GA counties
could be rain-free by daybreak Sunday. Finally, due to all the rain
and north to northeast winds, high temperatures will be well below
Sunday and Monday: The mid-level trough and its closed low will
slowly move off the coast. The coastal storm will be moving away
from our area Sunday, followed by high pressure building from the
west. The high should settle over the Southeast by Monday. There
could be some remnant showers over our SC counties Sunday morning.
But these will quickly dissipate and move away by Sunday afternoon
as drier air moves into the area. Dry conditions are then anticipate
Sunday night into Monday. Gusty N to NW winds Sunday afternoon will
keep high temperatures well below normal. Low temperatures Sunday
night will also be well below normal due to northwest winds in a
cold air mass. High temperatures are expected to warm up on Monday,
being just a few degrees below normal.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
High pressure will bring dry weather and warmer daytime temperatures
to our area through Thursday. A cold front could bring showers on
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
The terminals will remain between low pressure developing and
tracking off the coast and high pressure ridging across the
western Carolinas into NE GA through the 0Z TAF period. This
pattern should support NNE winds of 15-20 kts with gusts around
30 kts through much of the TAF period, especially during the
daylight hours Saturday. In addition, winds between 1-2 kft with
strengthen to around 50 kts Saturday morning, remaining through
much of the day. These stronger winds are expected to result in
a period of LLWS over the terminals by 11Z and remain through
the rest of the period. Deep moisture combined with deep forcing
should promote heavier rainfall rates and lower ceilings by
mid-morning Saturday. The TAFs will feature IFR to MVFR flight
conditions developing during the mid to late morning hours and
persisting through the afternoon.
Extended Aviation Outlook: A coastal storm should bring IFR and low-
level wind shear through Saturday night. Gusty NE winds are expected
through Sunday evening.
Update: ASCAT data this evening indicate that 45 kt winds was
over portions of the outer GA waters. It is reasonable to
assume that Storm force wind gusts were occurring over AMZ374.
In addition, recent runs of the RAP indicate that gusts around
50 kts will occur more frequently Saturday morning into the
early afternoon. Gusts to around 50 kts across the outer GA
waters was also supported by HREF prob of 50kt winds with dBZ>20
over the outer GA waters on Sat, ranging from 30-50 percent. A
Storm Warning is in effect until 7 PM Saturday.
Tonight: Hazardous marine conditions are expected over all coastal
waters tonight as a tight pressure gradient remains in place
between high pressure inland and low pressure lifting off the
northeast Florida and Georgia coasts. Gale Warnings are now in
effect for all waters through the night. The worst conditions
are expected after 06z when gusts to 45 kt will be common,
except around 35 kt in the Charleston Harbor. There is also a
potential for storm force gusts over the outer Georgia waters
late tonight, but confidence in duration and frequency were too
low to hoist a Storm Warning at this time. Seas will build to
7-10 ft across the nearshore waters and 10-15 ft beyond.
Saturday: Dangerous marine conditions are expected. Strong High
pressure over the northeastern U.S. in the morning will trend
offshore with time. Meanwhile, a strong storm will continue to trend
to the northeast with time, paralleling our coast. The interaction
between these two synoptic features will generate a steep surface
gradient. Gale force winds are expected across all of the ocean
waters, with gusts exceeding 40 kt beyond 10 nm during the day and
evening. For the Charleston Harbor, a Gale Warning is in effect
through the evening. Then, near gale force gusts will persist
during the overnight hours for the harbor. As for seas, very
steep, short-period wind waves are expected. Seas are expected
to exceed 10 ft beyond 10 nm and reach near 15 ft across the GA
waters beyond 20 nm. Winds and waves will start to lower late at
night as the low moves away.
Sunday: The coastal low will gradually move away to the northeast.
Meanwhile, high pressure will build from the west. This will cause
winds and seas to trend lower across the waters.
The remaining Gale Warnings should expire during this time period,
replaced by Small Craft Advisories due to gusty winds and elevated
Monday and Tuesday: High pressure will be over the Southeast. Winds
and seas are expected to continue their downward trends, with wind
gusts dropping below 25 kt for all of our ocean waters by late
Monday. However, seas may remain elevated just enough for the GA
waters beyond 20 nm that a Small Craft Advisory could persist there
A considerable coastal flood event will continue through Sunday
morning due to a combination of high astronomical tides, strong
NNE winds, and low pressure. Minor to moderate coastal flooding
is anticipated with Saturday evening`s high tide while major
coastal flooding is expected during the Saturday/Sunday morning
high tides. It still looks like the Saturday morning high tide
will be the highest of the event since the wind direction/speeds
will be most favorable for surge, and a Coastal Flood Watch has
been issued. Models are trending toward a more offshore wind
component by Sunday morning which should start to bring down the
anomalies late Saturday night.
Another important aspect of the forecast will be the extent of
rainfall. If showers occur around/at the time of high tide, any
future or ongoing flooding could be exacerbated. The best chance
for precip will be this evening through Saturday evening.
In addition, large waves and the strong winds will occur in
tandem with the high tides, resulting in erosion along
High Surf: Breakers over 5 feet are expected late tonight into
Saturday in the surf zone. A High Surf Advisory has been issued.
Record Low Maximum Temperatures for Nov 5
CHS: 50 set in 1995
CXM: 52 set in 1950
SAV: 54 set in 1950
Record Low Maximum Temperatures for Nov 6
CHS: 49 set in 1953
CXM: 50 set in 1953
SAV: 54 set in 1953
GA...High Surf Advisory from 2 AM EDT Saturday to 6 AM EST Sunday
Coastal Flood Watch from 8 AM EDT Saturday through Saturday
morning for GAZ117-119-139-141.
Wind Advisory from 2 AM to 3 PM EDT Saturday for GAZ117-119-
SC...High Surf Advisory from 2 AM EDT Saturday to 6 AM EST Sunday
Coastal Flood Watch from 8 AM EDT Saturday through Saturday
morning for SCZ048>051.
Wind Advisory from 2 AM to 3 PM EDT Saturday for SCZ048-051.
Lake Wind Advisory from 2 AM EDT Saturday to 6 AM EST Sunday
MARINE...Gale Warning until 7 AM EST Sunday for AMZ352-354.
Gale Warning until 11 AM EST Sunday for AMZ350.
Storm Warning until 7 PM EDT Saturday for AMZ374.
Gale Warning until midnight EDT Saturday night for AMZ330.
Area Forecast Discussion
National Weather Service Lake Charles LA
953 PM CDT Fri Nov 5 2021
With clear skies this evening temperatures have already dropped
into the mid to upper 40s across the lakes region in southeast
Texas and central Louisiana. While down along the I-10 corridor
temperatures are hanging out in the lower 50s where dew points
are a bit higher. But all locations are expected to drop slowly
through the overnight.
The really great news is the weekend will be great to get outside
and enjoy the football games around the area or just go for a nice
hike in the forest or golf. It beats the 90s of several months ago
for sure. This great weather will continue into next week with
temperatures warming slowly each day. The next system looks to
move through around Thursday with some showers along and ahead of
the front. Zones look fine no updates are planned.
.PREV DISCUSSION... /issued 648 PM CDT Fri Nov 5 2021/
For the 11/06/2021 0000 UTC TAF package.
Recent GOES CH 2 VIS and CH 13 IR satellite imagery shows back
edge of stratocu deck oriented north to south along the
Atchafalaya Basin, then westward toward Vermilion Bay, with all
TAF sites west of this line and currently SKC. The primary issue
for tonight into Saturday morning will be whether these clouds
propagate back to the west, resulting in ocnl VFR or possibly
MVFR cigs especially at LFT/ARA. NAM guidance is most bullish on
this, but HRRR and ARW also show hints of some back-building low
clouds. That said, confidence is not real high to re-insert cigs
at this time so kept sky conditions VFR with just SCT clouds
encroaching on the LA terminals late tonight, and will re-visit
this possibility with the 06Z TAFs or amend if conditions warrant
before then. Otherwise, winds will be light and northerly
tonight, strengthening to 5-10 KT during the day Saturday.
PREV DISCUSSION... /issued 318 PM CDT Fri Nov 5 2021/
SHORT TERM [Rest of Today through Sunday]...
High pressure will prevail over the area through Sunday with
continued cooler than normal temperatures. A light northerly flow
with elevated wind gusts this afternoon and evening will weaken
overnight with continued light northerly flow into Saturday. Low
pressure will develop across the plains on Sunday with a gradual turn
to southerly flow across our area by Sunday afternoon. No
precipitation is expected through Sunday as the airmass will
remain dry during this timeframe. 06
LONG TERM [Monday through Friday]...
Region will begin the long range period amid a continuing slow
warming/moderating trend with high pressure prevailing at the
surface and aloft. Relatively dry air in place and little to no
cloud cover will yield a large diurnal temperature range, with lows
MON morning in the mid/upper 40s warming into the lower/mid 70s MON
Increasing SFC MSTR, especially across coastal SE TX/SW LA, will
result in slightly warmer lows TUE morning, but inland locations are
still expected to bottom out in the mid to upper 40s. A shortwave
trof is progged to traverse the area TUE afternoon and evening,
breaking down the ridging aloft and nudging the SFC/low level ridge
farther to the east. An increase in cloud cover is expected, mainly
in the form of some high cirrus, but the passage of this feature
will otherwise be unremarkable.
Generally light return flow will continue to chip away at the dry
airmass, with temperatures WED morning in the 50s for most area
except parts of east central LA. The magnitude of return flow will
increase markedly on WED as a robust upper trof pushes east of the
FOUR Corners and into the Southern Plains. Rain chances will start
to increase WED night, mainly via WAA, but the best rain chances are
forecast THU into THU night with the upper trof and associated
frontal passage. There remains some spread in global models
regarding the exact timing, but at least some narrowing looks to
have occurred with the 12Z guidance pointing toward THU or THU night.
Some low end PoPs were retained for FRI, but if subsequent runs
continue to hone in on THU, then these will be trimmed out of future
Light to moderate offshore flow will continue into early Sunday as
high pressure prevails over the northwest Gulf Of Mexico. By late in
the day Sunday...a gradual turn to onshore flow will commence as low
pressure develops across the central plains. Onshore flow will
continue into Wednesday with a cold front approaching the coastal
waters very late Wednesday night. Rain chances will begin to uptick
as the frontal boundary approaches late in the day Thursday.
.PRELIMINARY POINT TEMPS/POPS...
AEX 39 68 41 72 / 0 0 0 0
LCH 43 69 45 72 / 0 0 0 0
LFT 45 70 46 72 / 0 0 0 0
BPT 42 69 44 72 / 0 0 0 0
Area Forecast Discussion
National Weather Service Marquette MI
654 PM EDT Fri Nov 5 2021
.SHORT TERM...(This evening through Saturday)
Issued at 234 PM EDT FRI NOV 5 2021
Water vapor imagery and RAP analysis show a vigorous shortwave
trough approaching from the Dakotas, and this will be the main
weather feature to impact the short term portion of the fcst.
Downstream, ridging extends from Manitoba through the Northern and
Central Plains. At the sfc, a high pres ridge extends from TX to New
England, and a low pres trough is emerging over the eastern Dakotas.
Between these features, sw winds have increased over Upper MI today
with gusts of 20-30 mph across much of the area. Under partly cloudy
skies, afternoon temps have risen to around 50F.
Wind will be the main fcst concern heading into tonight as low-level
wind fields strengthen between the nearly stationary high pres ridge
to the south and east and the low pres trough over the Northern
Plains which will continue to advance toward Upper MI. The magnitude
of the low-level jet will be upwards of 50kt as it translates across
the area tonight. With the loss of daytime heating/mixing, gust
potential tonight will diminish from what it could be with the
passing low-level jet. The exception will be in the downslope areas
near Lake Superior, especially from Marquette County eastward. The
ssw wind direction will be quite favorable for Marquette city and
surrounding areas this evening. Fcst soundings show a window this
evening where 45kt winds could be tapped for the city of Marquette.
Otherwise, gusts of 40-45mph should occur for a time from around Big
Bay eastward past Grand Marais. Gusts to 30-40mph are expected
elsewhere in the areas that see downsloping with s to sw winds. The
rest of the area should see some gusts of 20-30mph for at least part
of the night, though nighttime stability will be working against
gustiness. The strong s-sw winds will maintain the threat of
lakeshore flooding for Delta and southern Schoolcraft counties
through tonight where advisories are already posted.
With isentropic ascent ahead of the shortwave, there might be just
enough column moistening for a few showers to develop over the
western counties late. Have nothing more than a slight chance
mention in PoP grids though, as best dynamics with shortwave lift
west and north of the area. Lows tonight will only fall off to the
upper 30s/lower 40s due to winds/clouds.
Saturday, as the Plains shortwave moves across the area, any
isolated light rain showers will move from west to east across the
northern tier of the cwa through the day. Showers will end late in
the afternoon west, but out east, isolated showers could linger into
Saturday evening. Despite an increase in 850 temps from the previous
day, cloud cover from the passing shortwave will generally keep a
lid on the warming. Expect highs in the lower to mid 50s. Any
lakeshore flooding in Delta or Schoolcraft counties should be ending
later in the day as the shortwave moves through the area and the
pres gradient relaxes a bit.
.LONG TERM...(Saturday night through Friday)
Issued at 309 PM EDT FRI NOV 5 2021
After a short wave over northern Lake Superior lifts off to the
northeast Saturday night, impressive ridging will continue to build
into the Upper Great Lakes region Sunday and persist into Monday,
with 850 mb temps Sunday afternoon around 11 C which would be around
the 95th percentile of the CFSR climo. However, some upper-level
cloud cover on Sunday will keep temps from reaching their full
potential given the anomalous warmth aloft. Still, should see highs
in the upper 50s to mid 60s on Sunday, and would not be at all
surprised if the models are underdoing the amount of PBL mixing
resulting in a cool bias. Monday looks similarly warm south and
east, but a dry cold front sweeping across the area during the day
will lead to slightly cooler temps over the west half, in the mid to
A cooler day is expected Tuesday behind the front, but conditions
will most likely stay dry. Have maintained some slight chance to low-
end rain shower chances due to earlier EC runs developing a wave and
lifting it north into the area, but the trend is towards Tuesday
being dry and these can probably be removed in the next forecast
The big story of the long-term period will be a strong upper-level
jet moving onshore into the western CONUS on Wednesday with the lead
short wave quickly developing into a potent fall system. While there
is a strong signal among all of the model guidance for a big system
over the middle of the country by Thursday, there is still notable
spread among the ensemble members. The primary mode of variability
is the amplification of the upper-level pattern and thus the timing
of the wave, but of course there is some uncertainty in this depth
of the resultant low as well. A period of stronger winds, especially
on the lakes, looks like a good bet for Thursday. Less certain is
precip chances and precip type. The deterministic models continue to
show the low wrapping up over Minnesota, which would keep the U.P.
in the warm sector. However, the 06z GEFS ensemble mean surface low
and 850 mb low track would suggest there is at least a chance that
the system ends up less amplified and tracks farther souther, thus
bringing snow to the U.P. That is definitely not the most likely
outcome, but it is one that can`t be completely ruled out yet this
far out. For this forecast, will continue the trend of previous
shifts by making all precip rain through Friday. Depending on the
evolution of the system, a transition to lake effect snow looks
possible Friday night into next weekend, although depending on the
evolution of the system, that could happen anywhere from the north
wind lake effect belts to the south wind belts.
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 654 PM EDT FRI NOV 5 2021
VFR conditions should prevail at IWD/CMX/SAW thru this fcst period.
Winds will remain gusty through most of this forecast period.
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 234 PM EDT FRI NOV 5 2021
Tightening pres gradient between a high pres ridge to the se and a
low pres trough approaching from the w will lead to increasing sw to
s winds across Lake Superior later today into tonight. Winds will
increase from 20-30kt this afternoon to 35-40 kt across eastern Lake
Superior this evening, where a gale warning is still in effect. A
few gale force gusts may occur elsewhere as well, mainly at high obs
platforms. Winds will diminish for Sat, but gusts will likely remain
in the 20-30kt range for much of the lake for a good part of the
day. By Sat evening, gusts should be under 20kt across the lake.
These lighter winds will continue into Sun. A weak trough will then
sweep across Lake Superior late Sun night/early Mon but winds will
generally remain light, under 20 knots into Tue.
Lakeshore Flood Advisory until 2 PM EDT Saturday for MIZ013.
Lakeshore Flood Advisory until 4 PM EDT Saturday for MIZ014.
Gale Warning until 8 AM EDT Saturday for LSZ249>251-266-267.
Gale Warning until 5 AM EDT Saturday for LSZ248.
Gale Warning until 8 AM EDT Saturday for LMZ221-248-250.