Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/12/21
Area Forecast Discussion
National Weather Service Glasgow MT
707 PM MST Thu Nov 11 2021
.DISCUSSION...
EVENING UPDATE:
Deep Low over Minnesota and Wisconsin is actually doing a little
bit of retrograding this evening. Main effect for us will be the
winds will stay elevated a bit longer and a deck of stratus will
remain over the area from Glasgow eastward. Far eastern zones are
reporting some light snow so have upped POPs to reflect this.
Little to no accumulation is expected with these snow showers. The
Low will start moving eastward again after midnight which will
lead to gradual clearing and winds diminishing over the area by
morning.
RMB
PREVIOUS DISCUSSION:
...Gusty winds to continue this afternoon while a light wintry
mix remains possible later Friday night...
Gusty winds from the N/NW still over a widespread area of our
region, but are expected to diminish after sunset tonight. A
little lingering light snowfall is also possible along the ND/MT
border this evening.
Our attention now turns to the next chance for precipitation which
increasingly looks like a wintery mix of rain/freezing
rain/sleet/and snow Friday evening through Saturday morning. The
overwhelming driving force for this event is the warm front over-
riding the colder air at the surface; but less certain is the
arrival of precipitation. Yesterday at this time, model precip
output was more convincing, but today, for lack of a better term,
it`s all over the place. Convection-allowing models like the HRRR
still show it fairly well, but light QPF. NAM and EC are delayed
and blows it up to 0.1 or more QPF in our NE zones between 09Z and
12Z. SREF is broad-brushed everywhere light QPF. GFS is dry. CMC
NH show mostly dry, but then brings a little QPF along our border
with Saskatchewan. I favored the HRRR in its depiction of timing
an precip mostly, but confidence is low. I guess if it is such a
subtle short-wave disturbance, then model data has difficulty
pinning it down. Ensembles show some support for it, but also just
as many members are not showing it either. Chose to err on the
side of caution still keeping a wintry mix in there, with reduced
PoPs for now.
Later this weekend, expect warmer than normal temperatures as high
pressure from the SW pushes the colder air away from our region
through Monday and early Tuesday.
Expect a significant cold front later on Tuesday, bringing
temperatures down below normal for the rest of the week.
&&
.AVIATION...
UPDATED: 0200Z
FLIGHT CONDITIONS: MVFR overnight, VFR most of Friday, VFR-MVFR
Friday night into Saturday morning.
WINDS: W-NW 15-25 kts with gusts to 35 kts at times overnight,
light and variable Friday morning, becoming S-SE 10-15kts Friday
afternoon.
SYNOPSIS: Low Pressure sitting over Minnesota will keep cloud
cover, elevated winds and light snow chances at KGDV and KSDY
through at least midnight. This feature will push east tomorrow
morning taking the cloud cover and winds with it. A warm front
develops over the area tomorrow and by tomorrow night brings a
chance of a wintry mix between 23Z and 18Z Saturday.
RMB
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 9 PM MST this evening For Fort Peck
Lake for Central and Southeast Phillips...Central and Southern
Valley...Garfield...McCone...Petroleum.
&&
$$
weather.gov/glasgow
Area Forecast Discussion
National Weather Service Hanford CA
349 PM PST Thu Nov 11 2021
.UPDATE...Updated air quality issues.
&&
.SYNOPSIS...
Areas of dense fog will develop after midnight and will continue
through the late morning hours for the majority of the valley.
Otherwise, temperatures will trend upward to well above average
through the middle of next week. Dry weather will persist with
areas of dense fog possible each morning in the valley.
&&
.DISCUSSION...
Tomorrow morning is looking to be a good setup for Tule fog
across the southern San Joaquin Valley. Latest HRRR soundings show
ample low level moisture in the boundary layer capped by a strong
inversion/dry air aloft. Additionally, the surface and low level
winds are going to remain calm which will limit mixing. Lastly,
although still patchy in some places, a majority of the low clouds
in the valley have burnt off this afternoon. For all these
reasons we`ve gone ahead and issued a Dense Fog Advisory for the
valley starting at Midnight and continuing through 11 AM PST.
Visibilities of one quarter miles to as low as 200 feet are
possible.
Looking forward from Friday the weekend into early next week,
both the deterministic model output and ensembles show that an
anomalously strong ridge will remain parked over the region.
Latest NBM guidance indicates that temperatures will be between 5
to 10 degrees above average Friday through Tuesday for a majority
of the central California interior. Other than continued chances
of valley Tule fog in the morning, the overall pattern looks to
remain dry.
&&
.AVIATION...Areas of IFR to LIFR in dense fog and low ceilings
will develop in the SJ Valley after 08Z and will continue through
at least 19Z Friday. Otherwise, VFR conditions will prevail
elsewhere over the central California interior during the next 24
hours.
&&
.AIR QUALITY ISSUES...
On Friday November 12 2021... Fireplace/Wood Stove Burning
Status is: No Burning Unless Registered in Fresno... Kern...
Madera and Tulare Counties.
Further information is available at Valleyair.org
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
an/or to provide feedback.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from midnight tonight to 11 AM PST Friday for
CAZ302-303-306-307-310>312-314-315.
&&
$$
public...CMC
aviation....Bollenbacher
weather.gov/hanford
Area Forecast Discussion
National Weather Service Wilmington NC
638 PM EST Thu Nov 11 2021
.SYNOPSIS...
An approaching cold front will bring a chance of rain tonight
into Friday morning. A drying trend is expected to follow this
weekend with dry high pressure supplying seasonable temperatures.
Cooler air arrives early next week.
&&
.UPDATE...
A wave of clouds and showers are moving north across the Myrtle
Beach-Tabor city-Fair Bluff corridor currently. Forecast PoPs
have been increased across most of Horry, Columbus, and Bladen
counties for the next few hours to account for this rather
shallow convective activity. The latest HRRR suggests this
cluster of showers could make it into Wilmington between
10-11pm. Of greater concern is the potential for deeper
convection to develop off the South Carolina coast after
midnight after the last hint of the subsidence inversion
dissipates. While it`s tough to determine the trajectory of
convection that hasn`t yet formed, the bulk of the high-res
models suggest Southport and Wilmington have a good potential
for convection to develop in the 3-6 AM timeframe Friday
morning. Forecast PoPs/Wx have been updated to focus on this
potential. Otherwise changes with this forecast were generally
minor.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
Stacked low moving into the western Great Lakes tonight will drive a
cold front into the area from the west. Front is well displaced from
any dynamics and the stacked low has a rather large dry slot,
limiting moisture locally. A rather impressive 5h trough associated
with the low is helping push the front east, but the trough axis
remains to the west, keeping the coldest area out of the region
through Fri night. The front will have a narrow band of deep
moisture ahead of it, spreading over the area late this evening and
lingering through midday Fri or so. Precipitable water briefly
exceeds 1.5" Fri morning, but morning timing of the best moisture
means limited surface based instability. Mid-level lapse rates late
tonight and Fri morning are only 5.5 to 6 C/km. Convergence along
the front is also weak (flow slightly veers from south-southeast to
southwest). The only really favorable parameter for convection
tonight into Friday is a 115kt jet around 200 mb. Given the time of
year and nature of the front (well displaced from the low) the
typical scenario in this area is scattered showers, with minimal
lighting (most of which is offshore). Likely 2 rounds of showers,
weak to moderate convection moving in off the nearshore waters and
then a second band of weak showers moving in from the west which
slowly diminish to almost nothing by the time they reach the coast.
The result will be another rainfall event with many areas seeing
rainfall, but with most of those areas left wanting more. Rainfall
amounts will range from a couple tenths along the NC coast to a
couple hundredths across portions of inland SC. Cloud cover,
moisture and increased southerly flow overnight will keep lows well
above climo.
Low level winds do become more westerly during Fri afternoon, but
the flow aloft remains southwest. So while there may be some slight
cooling in the boundary level, it will not be enough offset
afternoon sunshine. Precipitable water drops to 0.50" or less during
Fri afternoon with an abundance of dry air above 850mb everywhere
around midday. Highs will end up several degrees above climo,
similar to slightly cooler than today. Clear skies and decreased
moisture Fri night will result in lows a little cooler than Thu
night. However, continued southwest flow Fri night will keep lows
above climo.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A deep mid level trough will move across the area for
the weekend with the headline of strong cold air advection. The main
front moves across Saturday evening so Saturday will be another warm
day with highs in the 70s. 850mb temperatures fall to around five
degrees c Sunday morning but a mixed boundary layer will inhibit
lows from falling to far past the middle to upper 30s or so. Some
brief warming Sunday ahead of the next push of cold air with highs
reaching the lower 60s and lows Monday a bit warmer closer to near
40.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
Cool and dry for the extended as the mid level pattern
will feature a trough moving off to the northeast replaced by a
mostly west to east pattern. 850mb temperatures approach freezing
levels later Monday into Tuesday morning which could lead to some
surface temperatures approaching the lower 30s. As usual
temperatures will be highly dependent on the position of the surface
high and the mixed boundary layer. Slight warming thereafter.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Shallow convective showers extending from MYR-CRE northward to
just east of the LBT airport should continue to move north-
northeastward over the next few hours, perhaps approaching the
ILM airport after 03z. MYR earlier reported reduced visibility
and ceilings in heavy rain, and this potential will continue in
the heavier precipitation. Of more concern is the expectation
that a new area of even deeper convection, possibly accompanied
by thunderstorms, will develop off the South Carolina coast
after 06z and move toward Cape Fear the ILM airport after 08z.
The potential for at least brief periods of IFR conditions will
exist in the 08-11z timeframe at ILM. Behind this convection,
generally VFR conditions should develop Friday morning as a cold
front moves off the coast. Some potential for MVFR ceilings in
stratocumulus clouds will exist as low level moisture is slow to
clear out Friday.
Extended Outlook...VFR conditions are then expected with dry
offshore winds behind the front late Fri through the weekend.
&&
.MARINE...
Through Friday Night...
Southerly flow will continue through Fri before becoming a
little more westerly Fri night. Slight strengthening of the
gradient ahead of the front increases winds to 15 to 20 kt
tonight into Fri. Speeds drop back to 10 to 15 kt Fri and Fri
with weakening gradient in the post front regime. Seas will
build from 2 to 3 ft this afternoon to 3 to 5 ft late tonight
and for the first part of Fri. Seas subside to 2 to 4 ft Fri
evening and 2 to 3 ft Fri night. A south to southeast wind wave
will remain dominant through Fri night.
Saturday through Tuesday...
Some bouts of cold air advection will keep winds somewhat
elevated at times but generally remaining at this point below flag
criteria. Some west to southwesterly winds of 10-15 knots will be in
place Saturday followed by a northerly flow of 10-15 knots Sunday. A
similar pattern will occur late Sunday into Tuesday with a brief
west to southwest flow followed by a stronger northerly flow perhaps
increasing to 15-20 knots which appears to be the strongest winds of
the period. Overall significant seas remain seemingly in check with
the changeable fetch and lack of very strong winds with mostly a
range of 2-4 feet.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...Coastal Flood Advisory until 7 PM EST this evening for NCZ107.
MARINE...None.
&&
$$
SYNOPSIS...ILM
UPDATE...TRA
NEAR TERM...III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...TRA
MARINE...III/SHK
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
931 PM EST Thu Nov 11 2021
.SYNOPSIS...
A cold front will move through the region this evening. A
disturbance will bring additional precipitation to the region
Friday afternoon into Friday night. Another system on Sunday
will bring another round of precipitation to the area.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
The main swath of rain is just about out of the forecast area,
leaving dry conditions for most of the rest of the overnight
hours. The eastward-moving cold front has brought about a brief
period of westerly winds and gusts to around 25-30 knots, but
winds behind the front are settling back into a southwesterly
direction. The HRRR is hinting at another weak surface trough
axis currently moving across Illinois and into Indiana, with a
few showers noted on radar. A 20-PoP was added to the
northwestern ILN CWA to account for this -- although the trough
may wash out, the cooler air moving in aloft may also aid in
some spotty shower development.
Temperature trends appear a degree or two cooler than previously
expected, with no significant adjustments to wind or sky cover.
Previous discussion >
Wind gusts will continue into the evening hours, however wind
gusts have diminished from earlier values. Due to this have let
the special weather statement expire and have removed wind
wording from the hazardous weather outlook for today. Rain will
continue to move through the region this evening. A cold front
will move through the area and cooler air will filter into the
region. Cloud cover will decrease later in the overnight hours.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Dry conditions will start out the short term. There are steep
low level lapse rates Friday into Friday night. Expect winds to
once again pick up during the day on Friday with a peak in the
afternoon hours. Wind gusts in the 30s will be likely with some
wind gusts upwards of 40 mph. Due to this have added the mention
for the potential for 40 mph wind gusts to the HWO for Friday.
Precipitation chances will increase during the afternoon and
continue into Friday night as an upper level disturbance moves
through. Increased precipitation chances Friday afternoon into
Friday night with this feature. As cooler air moves in Friday
night expect rain showers to transition over to snow showers
before tapering off.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Under a northwest flow aloft, much colder air will be in place
across the region on Saturday. Although it should stay dry, CAA
stratocumulus should be plentiful, resulting in mostly cloudy skies.
With a modest west wind, highs will only warm into the upper 30s to
the lower 40s.
A weak surface ridge will pass east across the Tennessee Valley
Saturday night. Despite this, clouds will linger. Lows will
generally be in the lower 30s.
A fast moving s/wv will dive southeast into the Great Lakes on
Sunday. Associated with another cold front, the chances for pcpn
will increase from west to east through the day. If the pcpn starts
early enough, a little snow may mix in, otherwise, it will be mostly
rain. Highs will range from the lower 40s north to the upper 40s
south.
For Sunday night, pcpn will gradually taper off overnight. As the
atmosphere cools, a little snow may mix in before pcpn comes
to an end.
An upper level trough will begin to pull east away from the Great
Lakes and Ohio Valley on Monday. This will allow surface high
pressure to gradually build east into the Ohio Valley. Clouds will
slowly decrease from the west during the day. It will still be cold
as the 850 mb cold pool will be slow to dislodge during the day.
After lows in the upper 20s to the lower 30s, highs will be in the
lower 40s.
Long range models concur that the upper level flow will transition
to a low amplitude mid level ridge into mid week. As this occurs,
surface high pressure will traverse the region, eventually allowing
return flow to work its way back into the area. Coldest morning lows
will be Tuesday morning (mid/upper 20s), but highs on Tuesday will
begin to recover (upper 40s/lower 50s). By Wednesday, highs will
warm into the upper 50s to the lower 60s.
A mid level trough is expected to develop into the Great Lakes and
Ohio Valley once again by the end of next week. This will push a
cold front slowly southeast into the forecast area. The chance for
rain will increase through the period with perhaps a little bit of
snow mixed in by weeks end as colder air filters slowly in from the
northwest.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Rain is currently moving eastward through the TAF sites, with
an expectation that this rain will gradually come to an end over
the next few hours. Along with this rain, there are some MVFR
visibilities and ceilings, and a few patches of IFR ceilings as
well. These conditions will improve after 03Z, with VFR
conditions expected thereafter. Behind a cold front, the
southwesterly winds will switch to the west, perhaps with a few
gusts to around 20 knots. Winds will diminish to around 10 knots
overnight.
SSW winds will increase in strength again tomorrow, with some
gusts to around 30 knots in the afternoon. VFR conditions are
expected, though clouds will increase late in the day, with a
chance of showers entering the picture after 22Z.
OUTLOOK...MVFR conditions are possible Friday night into
Saturday, and again Sunday night into Monday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Novak
NEAR TERM...Hatzos/Novak
SHORT TERM...Novak
LONG TERM...Hickman
AVIATION...Hatzos
Area Forecast Discussion
National Weather Service North Platte NE
544 PM CST Thu Nov 11 2021
.SYNOPSIS...
Issued at 319 PM CST Thu Nov 11 2021
H5 analysis from earlier this morning had a closed low
located just to the northeast of Minot North Dakota. A Broad trough
of low pressure extended to the south southeast of this feature to
the Gulf Coast of Louisiana. East and west of this trough, ridging
in the flow was present. A ridge extended up the west coast of the
CONUS, while a negatively tilted ridge extended from the Carolinas,
north northwest into eastern Ontario. At the surface, an elongated
area of low pressure extended from northern Wisconsin, west
northwest into northern Minnesota. A cold front extended south
southeast from Wisconsin into western Indiana and the lower
Mississippi Valley. Strong high pressure was located over the
northern Rockies, from western Wyoming into western Montana. Very
windy conditions were noted across western and north central
Nebraska this afternoon. Wind gusts as of 2 PM CST were as high as
58 and 61 MPH at O`Neill and Valentine. Skies were mostly clear and
temperatures ranged from 42 at Gordon to 51 at Broken Bow.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 319 PM CST Thu Nov 11 2021
Winds tonight into Friday are the main forecast concern in the
near term. For tonight: Winds will diminish slightly this evening
with some limited decoupling noted in the boundary layer.
However, am expecting winds to then increase overnight as an
arctic cold front backs into the area from the northeast. Winds
will increase around midnight in the northern forecast area, with
a transition south through 3 to 5 AM CST into the central and
southern forecast area. Winds will remain strong overnight and the
latest NAM12 and RAP BUFKIT soundings indicate a corridor of
mixed layer winds of 50 to 60 KTS along and east of a line from
western Cherry county, southeast into Custer county. For Broken
Bow, RAP and NAM12 BUFKIT soundings have 40 to 45 KT winds within
500 FT of the surface and mixed layer winds of 55 to 60 KTS from 1
to 6 AM CST overnight. Further north, over the existing high wind
warning, especially east of Valentine to O`Neill, high wind
warning criteria winds are supported by the latest NAM12 and RAP
BUFKIT forecast data. BL winds for O`Neill are around 45 KTS
overnight with mixed layer winds approaching 55 to 60 KTS. That
being said, will extend the existing high wind warning to 6 AM CST
Friday morning, and will add Custer, Logan and Hooker counties to
the high wind warning with this forecast package. Will let
Sheridan county expire at 11 PM MST as cold air advection is
limited overnight, which should keep winds from reaching high wind
warning criteria. As for lows tonight, went above statistical
guidance given the expected winds. This led to forecast lows in
the middle to upper 20s. Overnight into Friday morning, some post
frontal precipitation may develop over the far northeastern
forecast area within the wrap around zone of the exiting upper
level low. Lift is favorable in the dendritic zone favoring some
light snow. QPF`s are very light with this precipitation and given
the degree of dry boundary layer air to overcome, no snow
accumulation is expected. Winds will begin to relax slightly on
Friday morning, diminishing quickly in the west during the
afternoon hours. A warm front will begin to push into the far
western forecast area late Friday afternoon, but will arrive after
peak heating so highs will struggle to get out of the upper 40s
in far southwestern Nebraska. Elsewhere, highs will be in the mid
to upper 30s over north central Nebraska with lower 40s along the
I80 corridor from North Platte west to Chappell. The warm front
will track across the forecast area Friday night. Lows will be
early on with some rising temps expected in the western forecast
area overnight. Lows will range from the upper teens in the east,
to upper 20s in the west.
.LONG TERM...(Saturday through Thursday)
Issued at 319 PM CST Thu Nov 11 2021
Saturday will be warm across the area with highs in the 50s to
middle 60s. The warmup will be short lived however as another,
much weaker clipper system, dives southeast across the eastern
Dakotas Saturday night. This will usher in a decent cold front
Saturday night. Some post frontal precipitation may impact the
area Saturday evening behind the front and this has been
consistently advertised in the GFS model solns. Cross sections
behind the front indicate a short lived area of mid level
frontogenesis oriented across the center of the forecast area
Saturday evening. The latest NBM forecast today did increase pops
this forecast cycle. Will be holding onto these in the forecast
package given the support from the GFS soln. A broad ridge of high
pressure aloft will build into the western CONUS Sunday into
Tuesday leading to a warmup early next work week. After highs in
the 50s Sunday, readings will rise back into the 60s with some
lower 70s possible Tuesday. This will be followed by a strong cold
front Tuesday night into Wednesday with highs Wednesday and
Thursday in the 40s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 544 PM CST Thu Nov 11 2021
Deep sfc low pressure swirling across MN tonight will continue to
present strong northwest winds...32030g50KT...across ncntl
Nebraska overnight. Wind speeds will gradually subside after
midnight and throughout the day Friday.
A period of MVFR ceilings appears likely across ncntl Nebraska 06z
tonight through 18z Friday. Otherwise, VFR is expected across wrn
and ncntl Nebraska.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 6 AM CST /5 AM MST/ Friday for
NEZ005>010-024>029-037-038-094.
High Wind Warning until 11 PM MST this evening for NEZ004.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Lake Charles LA
527 PM CST Thu Nov 11 2021
.DISCUSSION...
For the 12/00Z TAF Issuance.
&&
.AVIATION...
The backside of the line of low clouds was from Ville Platte LA
...to Lake Charles and Sea Rim State Park, TX. Winds were light
northerly as surface high pressure filtered into the area. The
line of MVFR low clouds will continue to move south and clear
LFT/ARA/LCH between 00Z and 02Z. Clear skies and light winds
overnight may setup some patchy fog towards morning. Have opted to
include mention of said fog in the LFT/ARA TAF set. Visibilities
under ideal conditions could definitely get down to a mile between
09Z-12Z. There is some indications in model guidance that suggest
we are on track for at least some patchy fog. Fog should lift
fairly quick tomorrow morning with VFR expected the rest of the
day on Friday.
&&
.PREV DISCUSSION... /issued 340 PM CST Thu Nov 11 2021/
SYNOPSIS...
Cold front continues to progress east acrs the area, and should
be exiting the CWA within the next hour or two. Much of the mid
and high level clouds have thinned and sctd out, leaving mostly
sunny skies. However, a lingering band of stratocu behind the
front continues to move south, but latest vsbl satellite trends
have shown hints of gradual dissipation/erosion, and think this
will continue through the late aftn/early evening. Outside of
these clouds, temperatures have warmed up since this morning, with
temps as of 3 PM ranging from the mid 60s (where the clouds have
been most persistent) to lower 70s.
KLCH radar shows no precip over inland areas, with the closest
showers now well offshore over the outer coastal waters south of
Vermilion Bay.
24
SHORT TERM...[Tonight through Saturday night]
Sfc high pres, currently centered over NW TX, will continue to
build over the region, with winds bcmg light and somewhat vrbl
overnight. Dry and cool conditions will continue to spread into
the area, with overnight lows falling close to seasonal normals in
the upper 40s north to lower 50s south. Recent HRRR and RAP13
guidance paint some patchy fog developing acrs portions of S Cntl
and SW LA late tonight, and this seems feasible as decent
radiational conditions set up later tonight under mostly clear
skies and light to near calm winds, and interact with any lingering
sfc moisture.
By Friday, the sfc high will quickly slide east, allowing a brief
wind shift back to an onshore direction during the day. Despite
this, moisture return should be limited and thus expect dry and
pleasant conditions with highs climbing into the 70s. A secondary
frontal boundary (dry due to lack of moisture) will sweep through
the area, ushering an even drier and cooler airmass into the
region for the upcoming weekend. By Saturday, a deep mid/upper
longwave trough will continue to shift east, with winds aloft
shifting to a northwesterly direction as the trough axis crosses
the lower MS Valley. This will maintain a dry and cool pattern
over the region. Lows Saturday morning will fall into the lower to
middle 40s acrs the area, with highs only reaching the lower to
middle 60s Saturday aftn as N winds maintain modest cold air
advection. The coldest temperatures of the period are expected
by Sunday morning as the center of the sfc high settles over the
region, with lows in the upper 30s north to lower 40s south. Some
patchy frost will be possible Sunday morning in some of the cooler
spots acrs cntl LA and the Lakes region of SE TX.
24
LONG TERM...[Sunday through Thursday]
Our next shortwave aloft is progged to cross the Plains on Sunday,
which will help push another sfc boundary across the forecast area
Sunday night into Monday. Forecast soundings show minimal moisture
in place for this feature to work with and thus POPs during this
time frame are basically nil. The very brief return flow possible
prior to frontal passage will allow temps to warm a bit from
Saturday with highs forecast to return to the lower 70s for the
majority of the forecast area.
Our dry pattern is expected to linger through mid-week before
another disturbance aloft crosses the area Thursday. With the Gulf
opening up in the mid/upper levels, enough moisture looks likely for
widely scattered showers to develop after midnight Wednesday
night...with rain chances increasing during the day on Thursday as
the shortwave aloft pulls a sfc front into the forecast area,
increasing lift. Forecast soundings indicate sufficient instability
for a few storms as well, especially with heating during the day
Thursday. Once the whole system moves out of the area Thursday
night, a few straggling showers should depart the area as well.
25
MARINE...
Moderate northerly winds will shift northeast overnight as a cold
front continues to move south and east of the coastal waters and
sfc high pres builds into the region. Winds will begin to veer
southeasterly through midday Friday ahead of a secondary front
that will sweep through the area during the aftn. Offshore flow
will re-develop in the wake of the front, with winds and seas
increasing Friday night into Saturday, likely requiring issuance
of Small Craft Advisories. Winds will diminish by late in the
weekend as sfc high pres builds over the region. Onshore flow is
expected to return by late Monday into Tuesday.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 45 74 42 61 / 0 0 0 0
LCH 50 73 46 64 / 0 0 0 0
LFT 52 75 46 62 / 0 0 0 0
BPT 51 75 46 65 / 0 0 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
628 PM CST Thu Nov 11 2021
.SHORT TERM...(This evening through Friday night)
Issued at 232 PM CST Thu Nov 11 2021
Earlier, we opted to upgrade the winter storm watch to a strongly
worded winter weather advisory for intermittent blizzard-like
conditions. The main concern remains the potential of blowing snow
with visibilities dropping down to a quarter mile or less at times,
but we`re not expecting those conditions to last long enough in
duration to warrant an upgrade to a blizzard warning. Please exercise
caution if you must travel Thursday evening through Friday morning.
Rain has exited west-central Wisconsin while snow approaches western
Minnesota from the northeast. Recent guidance continues to support 2
to 3 inch snowfall totals and strong winds gusting up to 50 mph
across west central and south central Minnesota. Snow ratios will
range between 7:1 to 11:1 throughout the event. Guidance continues
to paint 0.20 to 0.25 inch QPF amounts across western and southern
Minnesota. Snow showers will begin this evening as they pivot around
the low pressure to our northeast. Steady snow is expected for
several hours tonight, then gradually dissipate Friday morning.
Decent rates within the heavier snow showers and strong winds could
lead to intermittent blizzard-like conditions. Expect travel
conditions to deteriorate quickly for those locations.
For those not under a Winter Weather Advisory in eastern Minnesota
and western Wisconsin, periods of snow showers are likely overnight
with accumulations up to an inch possible. There is the potential
that we`ll lose ice crystals aloft as a dry slot wraps around the
system. This would lead to more of a drizzle scenario east of I-35.
Low temperatures will be at or below freezing and could lead to This
system quickly moves into the Great Lakes region and precipitation
will taper off by Friday afternoon. Temperatures struggle to warm
much with strong cold air advection aloft. Highs in the lower to mid
30s in Minnesota and mid to upper 30s in western Wisconsin. Winds
finally begin to taper off by Friday night. Low temperatures plummet
into the lower to mid 20s with mostly cloudy skies lingering into
Saturday.
.LONG TERM...(Saturday through Thursday)
Issued at 232 PM CST Thu Nov 11 2021
The main concern in the extended period is over the weekend as a
strong, but quickly moving clipper type system, affects the Upper
Midwest.
A warm air advection regime will begin Saturday morning in western
Minnesota in advance of the storm system that will be moving
southeast across the Northern Plains. Although the GFS is slightly
weaker and farther south then the EC, thermal profiles and warm air
advection are similar. Differences in these models show in the total
QPF amounts and location. As previously said, the GFS is farther to
the south and thus has better QPF amounts, and associated snowfall
totals along and south of I-94 with this system. The EC has these
amounts more across central Mn vs. I-94 and south. Even the ensemble
means of both the EC/GFS support only between 0.10 to 0.20 inch
amounts where the main band sets up Saturday night. Since this
system is a quick mover and the strongest forcing is in a 6 to 12
hour time frame, these QPF amounts of 0.10 to 0.20 inches looks
reasonable. Thus, snow ratios and where the DGZ can be maximized,
will be critical for any locally heavier amounts. Using the NBM 50
percentile of snowfall amounts shows between 1.0 to 1.5" of snow
north of I-94, with only trace amounts along the Iowa border. The 90
percentile increases these amounts to 3-4" and generally in the same
area.
After tonights/Friday system moves through, I wouldn`t be surprised
to see another Winter Weather Advisory issued for portions of MN/WI
Saturday night, and Sunday morning. Impacts will be minimal due to
the weekend and the time of day which will occur mostly Saturday
night.
If snowfall amounts are greater than expected, temperatures will be
lowered in the extended period, especially overnight lows.
No forecast changes are expected past Sunday, other than some
modification of temperatures, as the main storm track holds along
and north of the international border.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 628 PM CST Thu Nov 11 2021
Not expecting precip intensity to pick up until a secondary surface
trough moves through. This trough sends the winds to the northwest
and it`s just north of AXN as this TAF period starts. In terms of
cigs/vis/precip, no significant changes were made, with a dryslot
making it difficult to get precip into WI until late Fri morning as
convective snow showers develop. We did give wind speeds a boost,
with the RAP showing top of the channel winds pushing 55 kts at time
in RWFs. Based on the track of the surface low, AXN/RWF were the two
terminals we really boosted winds for.
KMSP...There are light returns approaching MSP from the west now,
though they have not been producing sub-VFR vsbys with its ra/sn mix.
RAP soundings show the deepest moisture and best chance for snow at
MSP coming between 6z and 13z, with some snow showery activity
possible late Friday morning into the afternoon.
/OUTLOOK FOR KMSP/
Sat...MVFR. Chc -SN/IFR overnight. Wind W 5-10 kts.
Sun...MVFR/IFR in mrng, bcmg VFR. Wind NW 10G20 kts.
Mon...VFR. Wind S 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Winter Weather Advisory until noon CST Friday for Douglas-Pope-
Stevens.
Winter Weather Advisory from 9 PM this evening to noon CST Friday
for Blue Earth-Brown-Chippewa-Faribault-Freeborn-Kandiyohi-Lac
Qui Parle-Le Sueur-Martin-McLeod-Meeker-Nicollet-Redwood-
Renville-Sibley-Stearns-Steele-Swift-Todd-Waseca-Watonwan-
Yellow Medicine.
WI...None.
&&
$$
SHORT TERM...BPH
LONG TERM...JLT
AVIATION...MPG
Area Forecast Discussion
National Weather Service Phoenix AZ
400 PM MST Thu Nov 11 2021
.UPDATE...
Updated Aviation
&&
.SYNOPSIS...
High pressure will prevail through early next week, resulting in
dry conditions and a continuation of the above normal temperatures
across the Desert Southwest. A cooling trend is then anticipated
early next week as the area of high pressure weakens. No rain is
expected through at least late next week.
&&
.DISCUSSION...
Latest RAP streamline analysis traces out an amplified pattern
across the western CONUS, with northwesterly flow situated between
an anticyclone off the Baja Peninsula and a low pressure system
across the upper Midwest. The ridge to our west will move very
little over the next few days, resulting in a continuation of the
dry conditions, sunny skies and above normal temperatures.
Forecast remains largely based on the NBM, which indicates weighted
blend temperatures in the upper 80s for Phoenix each day. However,
roughly 20 percent of the ensemble indicates daily highs could reach
or exceed 90 degrees through Monday. It is not inconceivable
temperatures one or two of those days could also flirt with record
highs, which are in the lower 90s.
ECMWF/GFS/CMC ensemble means remain in good agreement cooler
conditions will arrive Tuesday as activity in the north Pacific
weakens the aforementioned ridge across the intermountain West.
However, temperatures will likely remain above normal through at
least Wednesday. Meanwhile, model ensemble suites indicate no
realistic chances for precipitation through at least next Thursday
with the overall pattern resembling the La Nina composite.
&&
.AVIATION...Updated at 2300Z
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Clear skies will continue through Friday evening with overall
conditions nearly identical to the past 24 hours. Light NW winds
this evening will quickly revert back to E/NE. Similar to today, the
switch back to NW should occur later than usual and closer to
sunset.
Southeast California/Southwest Arizona including KIPL and KBLH:
Under clear skies, only a period of gusty north winds will present a
weather impact through Friday evening. Gusts ~20kt will be common at
KBLH before decoupling in the evening. While a northerly component
will be favor much of the time, a time frame of backing west winds
should affect KIPL late tonight.
&&
.FIRE WEATHER...
Saturday through Wednesday:
Persistent high pressure and dry conditions will be seen across
the region through the period leading to above normal temperatures
through at least Tuesday. Winds will generally be light and favor
diurnal patterns, but some light afternoon breezes will be possible
on most days. Min RH values each day will mostly fall into the
teens, while max RH values will be 35-50%.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Hirsch
AVIATION...18
FIRE WEATHER...Kuhlman
Area Forecast Discussion
National Weather Service Pueblo CO
301 PM MST Thu Nov 11 2021
.SHORT TERM...(This evening through Friday)
Issued at 235 PM MST Thu Nov 11 2021
Sunny, breezy and mild across much of the area today, though obs and
web-cams around Leadville have indicated on/off snow showers for
much of the day, as strong nw upper flow continues to wring out
moisture over/near the nrn Sawatch/Mosquito Ranges. Windiest spots
have been over the central mountains as well, with gusts 55-65 mph
over the peaks and through Cottonwood Pass, and gusts 30-40 mph at
lower elevations around Buena Vista and Salida. Have also see some
fairly strong winds over the higher elevations in Teller County and
across the Rampart Range, where some gusts to 50 mph have been
noted in mesonet data this afternoon.
For tonight, snow showers will persist around Leadville and over the
surrounding mountains, though most models show a diminishing trend
to precip after midnight. Accums should stay fairly light, with
another 1-3 inches over mainly higher west facing slopes. At lower
elevations, clouds increase and winds decrease tonight, with perhaps
a sprinkle or two out of the mid-level cloud deck over the far ern
plains near the KS border. Weak cold front dropping south through
the plains may keep nly winds stirred for much of the night,
especially east of I-25, where some gusts in the 15-20 mph range
will be possible after midnight. Min temps should stay similar to
last night, with warmest readings in mixed locations near the
eastern mountains.
On Friday, one more day of brisk nw flow across the area, with ever
present snow showers/flurries across the central mountains, though
accums look spotty and light. After a morning lull, winds will
become gusty over the mountains and valleys by midday, with some
strong n-nw winds mixing to the surface over El Paso County and on
the plains near the KS border. Least windy locations look to be from
Pueblo south to Trinidad, as weak surface low near TAD will keep ely
flow going through the afternoon. Max temps will remain within a few
degf of Wed readings.
.LONG TERM...(Friday night through Thursday)
Issued at 235 PM MST Thu Nov 11 2021
Friday-Sunday...Model solutions continue to increase northwest flow
aloft over our area, bringing some energy to the midwest. Looking at
the placement of said energy, most of the better dynamics will be
well east of our forecast area, and things are expected to remain
dry over the weekend. With the breezy winds overhead, some gustier
conditions could be possible on Saturday over parts of the
Continental Divide, but nothing worthy of any wind highlights.
Temperatures on Saturday will be warm once again, with the valleys
and higher terrain remaining mostly consistent with the last few
days while the plains should climb into the high-60s to low-70s. A
backdoor front is expected to push across the plains early on
Sunday. Conditions should remain dry with little moisture remaining
in the area, but it will serve to knock high temperatures down a few
degrees for Sunday afternoon.
Monday-Thursday...Warmer and drier conditions will persist into the
beginning of next week as upper-level ridging briefly builds in over
the area. Temperatures Monday and Tuesday will increase to well
above seasonal norms, with some places over the southeast plains
potentially hitting the low 80s on Tuesday. While a bit far out to
be completely sure, Monday and Tuesday could be seeing some
potential fire weather concerns. Current ensembles remain consistent
with moving an upper-level trough across the region around
Wednesday, however many of the deterministic solutions differ on the
southern extent of the system. The majority of the data suggests
that the main energy of the passing wave will remain mostly to the
north of our forecast area, which would greatly limit the
precipitation we receive. Regardless, an increase in precipitation
chances and a cooldown in temps is still expected for the latter
half of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 235 PM MST Thu Nov 11 2021
VFR at all taf sites the next 24 hrs. Gusty w-nw winds at KCOS will
persist until 02z-04z, then gradually diminish, especially after 08z-
10z. On Fri, light winds until 18z-19z, then stronger nw winds mix
to the surface bringing some gusts 20-25 kts by afternoon. At KALS,
gusty nw winds have stayed north of the terminal today, and HRRR
suggest this trend will persist into the evening with light and
variable winds overnight. On Fri, light winds in the morning, then
some stronger n-nw winds develop in the afternoon, with gusts to 20
kts possible. At KPUB, brief window for gusty w-nw winds from 22z
until 02z as stronger flow is just west of the terminal around K1V6,
then gradually diminishing nw winds expected overnight. On Fri, e-se
winds in the 8-14 kt range expected for most of the day.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...GARBEROGLIO
AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Tallahassee FL
900 PM EST Thu Nov 11 2021
.UPDATE...
Some changes were made to the forecast to account for the line of
showers currently entering our southeast Alabama counties and the
batch of showers in the Big Bend and southwest Georgia. Kept
thunder limited to northern Coffee, Dale, and Henry Counties, but
not expecting much, if any. PoPs were adjusted slightly farther
east overnight to adjust for the timing and weakening of the
showers.
Added a mention of patchy fog for most areas away from the coast
for tonight as the rain clears. ECP recently reported FG with 3/4
SM visibility, so felt it was prudent to bring patchy fog in a
bit earlier and expand it overnight as rain exits east. All other
forecast aspects remain on track.
&&
.PREV DISCUSSION [628 PM EST]...
.NEAR TERM [Through Friday]...
The main highlight will be passage of a leading cold front tonight.
The surface front is now moving across northern and western Alabama,
where a broken line of showers accompanies the front. The front
should reach Dothan around 9 pm CT, Panama City around 11 pm CT,
Albany around 1 am ET, Tally around 3 am ET, and VLD around 5 am ET.
In advance of the front, the air mass is moist. Dewpoints have
quickly rebounded into the 60s across the entire service area.
Quite a few showers have already developed today in the Panhandle
and SE AL in confluent southerly flow. The low-level wind profile
that supported rotating cells this morning has let up as surface
winds have veered around more southerly, so conditions are now less
favorable for rotating cells.
In the first few hours after dark, numerous areas of low clouds and
possibly fog will develop in the moist pre-frontal air mass, making
for a murky evening. However, passage of the front will mark a wind
shift out of the northwest and the onset of dry advection. This
should scatter and dissipate any fog later tonight in the 1-3 hours
following the fropa (frontal passage).
The air mass behind this initial front will be a bit drier, but
it will not be much cooler. So temperatures are forecast to again
reach the 70s areawide on Friday afternoon.
.SHORT TERM [Friday Night Through Saturday Night]...
A secondary (dry) cold front moves in Saturday morning, reinforcing
the shot of cool air coming in from the north, however, return flow
will be nearly nonexistent due to Fridays` cold front. This means
most, if any, shower activity will be pinned to areas near/along the
Gulf Coast and over the Gulf waters. Post-frontal, we can expect a
transition to cool, dry, and clear sky conditions. The 18Z HRRR has
dewpoints falling into the low 30s and upper 20s in the wake of
these two cold fronts. Expect a sharp temp gradient with daytime
highs in the mid 60s in SE Alabama and in the mid 70s in the FL Big
Bend. Overnight lows generally follow a similar pattern with
portions of SE Alabama being in the mid 40s, and portions of the
FL Big Bend being in the mid to upper 50s.
.LONG TERM [Sunday Through Thursday]...
High pressure dominates throughout the long term, the GEFS
ensembles show pretty good agreement with the 500mb heights
through next week being relatively zonal. This means we`ll remain
cool through Tuesday, followed by a warming trend that begins on
Wednesday through the weekend. Daytime highs will generally remain
locked in the 60s through Tuesday, followed by a warming into the
mid 70s by Thursday. Overnight lows remain locked in the 40s,
with some areas in SE AL and SW GA making it into the upper 30s, a
slight warming of overnight lows into the upper 40s is expected
by Thursday morning.
.AVIATION...
[Through 00Z Saturday]
Occasional MVFR cigs and SHRA ahead of a cold front will become
more numerous overnight with a period of IFR likely at the
terminals. Cigs will begin to lift in the wake of the cold front
with a return to VFR on Friday. Southerly winds will veer to the
northwest in conjunction with the frontal passage, remaining at
or below 10 knots.
.MARINE...
Onshore southerly flow will prevail into this evening as high
pressure is situated off the eastern seaboard. Winds will become
northerly beginning Friday behind a cold frontal passage. Another
front on Saturday will bring stronger offshore winds and at least
small craft exercise caution conditions on Saturday and Saturday
night. Moderate offshore winds will continue into early next week.
.FIRE WEATHER...
A weak cold front will pass by the districts tonight, with scattered
showers and possibly a thunderstorm preceding the front. A stronger
reinforcing front will arrive on Friday night. A lull in the wind
fields between these fronts will come on Friday afternoon, leading
to low dispersion values. In contrast, an increase in wind on
Saturday behind the stronger front will lead to areas of high
dispersion values. A drier air mass will arrive on Friday and
Saturday.
Areas of fog are possible tonight in the moist air mass before the
first cold front. No fog is expected on Friday night due to the
arrival of drier air.
.HYDROLOGY...
Rainfall amounts will generally be around half an inch or less,
primarily in SE Alabama and SW Georgia as a result of todays` precip
ahead of the cold front. Isolated higher amounts are possible within
heavy showers. Thunderstorm potential is low. There are no flooding
concerns at this time.
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur (while following all local, state, and CDC guidelines) by
calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 62 78 51 71 39 / 20 10 10 10 0
Panama City 61 76 54 68 41 / 20 0 10 0 0
Dothan 54 73 47 64 34 / 50 0 0 0 0
Albany 59 75 47 67 36 / 30 0 0 0 0
Valdosta 63 76 51 70 38 / 20 10 0 10 0
Cross City 63 79 57 73 42 / 10 10 10 20 0
Apalachicola 63 76 56 70 43 / 20 10 10 10 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 1 AM EST /midnight CST/ Friday for
Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...Young
NEAR TERM...Haner
SHORT TERM...Oliver
LONG TERM...Oliver
AVIATION...99
MARINE...Oliver
FIRE WEATHER...Haner
HYDROLOGY...Oliver