Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/27/19
Area Forecast Discussion
National Weather Service Dodge City KS
551 PM CST Tue Nov 26 2019
...Updated Aviation Section...
.SHORT TERM...(This evening through Wednesday)
Issued at 258 PM CST Tue Nov 26 2019
Basically the hrrr updates though the day have continued to maintain
a very small area of our extreme west central Kansas counties with
the potential for one to three inches of snow. This will coincide
with the pivoting southern end of the the snow band now focused
across northwest kansas over far northern Trego and perhaps parts
of Scott and Lane counties. The surface low has moved from se CO
this morning to immediately south of the DDC CWA with a surge of
steep low level lapse rates. Even with the surge of dry air, the
front overtaking the area should relegate red flag criterion of Rh
too high for warning. The strongest winds should be developing by
late afternoon and continuing through the evening and be focused
across the south central Kansas counties, where best potential
(Clark - Comanche- Barber) for high wind gusts to 60 mph will be.
Gusts to 50 knots have already been recorded at Med Lodge. Any snow
accumulation across northern sections of Trego and areas southwest
will cause significant blowing into the early evening as the
isallobaric pressure increases ramp up the wind speeds through
midnight. Rapid clearing and dry air will lead to much colder
temperatures tonight, likely in the low teens west - and not out of
the question to see some single digits in the ark valley.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 258 PM CST Tue Nov 26 2019
Another storm system is on the heels of our current one. The
impacts should begins as early as Wednesday night as moisture and
warm advection develop. There appears to be a relative wet period
Thursday and into Friday. A chance for areas of rain of freezing
rain could occur Wednesday night and early Thursday as the residual
cold air is still in place, however with time the models warm the
layer though and airmass change, with instability offering a chance
for storms along with warmer temps in the 50s to 60 by Friday.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 549 PM CST Tue Nov 26 2019
As the latest storm system pulls away tonight, expect improving
aviation weather as the ceiling will eventually scatter out later
on tonight (particularly in the 06-10Z time frame early Wednesday
morning). Winds will also be weakening during this time frame as
well. In the meantime, through 06Z, MVFR flight category is
expected to persist at GCK, DDC, and HYS (with HYS experiencing
some intermittent IFR closer to the backside of the storm, along
with light snow). In between storm systems, Wednesday`s aviation
weather looks tranquil.
.PRELIMINARY POINT TEMPS/POPS...
DDC 21 42 29 40 / 10 0 70 80
GCK 16 41 28 41 / 20 0 60 70
EHA 18 43 28 43 / 0 0 70 50
LBL 18 43 27 41 / 0 0 80 70
HYS 21 38 25 38 / 70 0 50 80
P28 26 46 30 41 / 0 0 70 90
High Wind Warning until 9 PM CST this evening for KSZ063-064-
Winter Weather Advisory until 9 PM CST this evening for KSZ030-
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
737 PM CST Tue Nov 26 2019
737 PM CST
Only minor change to going forecast was to add isolated thunder
for this evening, as a few embedded cells have exhibited
lightning across parts of eastern CWA and southern Lake Michigan
early this evening. Expect this to continue to be the case through
the evening, as RAP mesoanalysis indicates weak 100-300 J/kg of
MUCAPE currently in place, and instability will only increase
with continued warm/moist advection tonight. High-res CAM guidance
suggests additional waves of showers/embedded thunderstorms will
continue to spread northeast across the forecast area, with an
increase in coverage and low-topped thunder potential likely from
11 pm/midnight onward as warm sector advances northward ahead of
deepening surface low pressure tracking to our northwest through
early Wednesday morning. Previous discussion of instability
trends, wind fields, long hodographs and marginal isolated severe
threat remain valid for overnight. Going forecast otherwise in
great shape, and no changes made except for adding the
aforementioned evening thunder.
238 PM CST
Through Wednesday night...
Our potent storm system is taking shape early this afternoon with
the core shortwave beginning to eject out across western Kansas.
Associated strong upper jet divergence is facilitating pressure
falls eastward across the Central Great Plains, and these pressure
falls will roughly telegraph the location of the surface low into
the evening hours as it tracks northeastward towards central Iowa.
Light shower activity continues to develop across the region as low-
level warm advection is really beginning to crank upstairs. This
activity will remain light through the afternoon hours with perhaps
a local minimum in activity south of I-80. As we work into the
evening hours, however, the addition of increasing support from an
incoming upper-jet should allow the slug of rain currently across
Arkansas and southeastern Missouri to spread into our region.
Afternoon model guidance continues to support the potential for a
sliver of modest elevated instability to develop through the evening
hours in the expanding warm sector south and east of the surface
low. Forecast soundings show a rather limited potential for truly
surface-based inflow, but kinematic profiles depict extremely strong
wind fields immediately off the surface. The attendant robust large
scale forcing for ascent ahead of this system may support the
development of a broken line of low-topped convection, which could
attempt to push into the southwestern portions of the CWA after
about 11 PM. Given the aforementioned kinematics in place and
already fast forward storm motions, it won`t take much to translate
some 50 to 60 mph wind gusts to surface if this convective line is
is deep enough. It continues to look like any linear convection
would begin to outpace what little surface-based instability there
is after 3-4 AM as it tracks towards the Chicago area and would
overall expect a decrease in storm intensity/depth as a result.
Finally, as was alluded to in the overnight discussion, in the face
of such strong and stretched-out wind fields, we can`t completely
discount the potential for a brief QLCS tornado spin-up given the
presence of line-orthogonal deep layer shear vectors which should
help keep convective updrafts propped up against any surging
The main story with this system, however, continues to be on the
very strong wind potential into Wednesday. We have upgraded the High
Wind Watch to a High Wind Warning for all of northeast Illinois and
northwest Indiana with the potential for widespread wind gusts well
into the 50 mph range, occasionally to 60 mph. Still some questions
about how deeply we can mix in the developing cold advection regime
on Wednesday morning/afternoon, but there is enough of a signal in
the model guidance to support the wind headline upgrade. The window
for highest gusts will be the mid-late morning hours on Wednesday
and through the mid-afternoon before things gradually abate into the
Low precipitation chances will linger for those north of I-80 into
the mid-afternoon hours on Wednesday as temperatures fall into the
30s with a strong non-diurnal temperature trend. It continues to
look like cloud depths will diminish quickly enough to minimize the
potential for any wintry precipitation as surface temperatures fall
below freezing Wednesday evening.
238 PM CST
Thursday through Tuesday...
Thanksgiving day continues to look fairly benign after the active
weather period on Wednesday. Light winds will prevail although cloud
cover will likely be prevalent holding high temperatures down in
the mid to upper 30s area-wide. The next lead shortwave
disturbance--caught up in the fast southwesterly mid-level flow
spread across the nation`s midsection--now looks to wash out west
of our region Thursday afternoon and evening, thus limiting the
potential for additional precipitation during this period.
The next strong storm system is currently dropping in towards the
Pacific Northwest and California coastline, will finally spread
east across the Plains towards the end of the week and weekend. As
is typical with these deep upper-level systems, we`ve noted an
incremental slowing trend in today`s guidance, and have begun to
pare PoPs back a bit, holding them back until later in the day on
Friday. This system`s current track once again places us more on
the warm side, likely greatly limiting the wintry weather aspect
although some rain and snow will be possible mainly north of I-80,
but no accumulations are anticipated at this time. Could see more
in the way of light snow towards the end of the weekend and Sunday
night on the backside of this system as the main upper low begins
to pivot in overhead.
For the 00Z TAFs...
* Ceilings quickly deteriorating to IFR early this evening and
possibly LIFR late this evening and overnight.
* Showers and drizzle this evening through early Wednesday
* Potential for occasional lightning strikes and higher tops early
this evening, with higher chances for thunderstorms late
* Southwest to west winds gusting to 45 to 50 kt on Wednesday.
Active period expected with a high likelihood for impactful
weather this evening through Wednesday. Latest radar imagery
depicting scattered rain lifting across parts of northern IL and
northwest IN. Waves of rain are expected this evening through
early Wednesday morning and although may only reach moderate
intensity, will likely see vis periodically fall to around 2sm.
Continue to monitor thunder potential this evening through early
Wednesday morning, with even some thunder and higher tops noted
just to the south of the terminals and more recently to the north.
The potential for an occasional lightning strike and higher tops
remains this evening given increasing instability aloft, and so
have included a VCTS for a few hours this evening. This potential
should lower later this evening, but return later tonight as a
line of storms is expected to swing across the terminals. With the
passage of these storms, precip chances lower through the
morning, though some light rain showers may be possible for a time
through midday Wednesday. Ceilings are on the way down at this
time, with low end MVFR likely here in the very near term, and
then with IFR ceilings becoming more likely soon after. IFR and
possibly LIFR ceilings then likely through early Wednesday, but
will quickly lift with the arrival of the storms. VFR ceilings
then expected for a few hour window Wednesday morning, but with
MVFR ceilings then returning for the remainder of the forecast
period. Varying winds expected through the period, with easterly
winds becoming southeast this evening, and then southwest and west
Wednesday. Rather strong gusts approaching 50 kt still expected
during the day Wednesday, with the highest gusts expected from
mid/late morning through mid afternoon.
We have converted the Storm Watch to a Storm Warning for the
nearshore waters of Lake Michigan. Southeast to south winds to 30
kt tonight will become southwest and eventually westerly Wednesday
morning and through the afternoon hours as they increase in
speed. Storm force wind gusts to 50 kt are anticipated on
Wednesday. While winds will remain gusty, they will subside
markedly Wednesday evening and overnight as high pressure quickly
begins to build in from the west.
IL...High Wind Warning...ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-
ILZ039...6 AM Wednesday to 6 PM Wednesday.
High Wind Warning...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ020-ILZ022...9 AM Wednesday
to 6 PM Wednesday.
IN...High Wind Warning...INZ001-INZ002...9 AM Wednesday to 6 PM
Lakeshore Flood Advisory...INZ002...noon Wednesday to 6 AM
High Wind Warning...INZ010-INZ011-INZ019...6 AM Wednesday to 6
LM...Small Craft Advisory...IL nearshore waters until 6 AM Wednesday.
Storm Warning...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...6 AM
Wednesday to 10 PM Wednesday.
Small Craft Advisory...IN nearshore waters until 6 AM Wednesday.
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Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
405 PM PST Tue Nov 26 2019
updated aviation discussion
Today will be the last day of cool, pleasant weather before a
couple cold storm systems arrive. An upper level trough of low
pressure arrives late tonight bringing rain, cold temperatures,
and mountain snow Wednesday and Thursday. Another system could
bring additional rain on Sunday through early next week.
.SHORT TERM (TDY-FRI)...26/129 PM.
Very cold upper trough continues to drop south along the west
coast today with impressive deepening of the surface low off the
coast of Oregon. The forecast remains more or less on track plus
or minus a few hours on the timing. The cold front is going to zip
through the forecast area at a rapid clip later tonight into
Wednesday morning, likely confining the period of heavier rain to
about 3 hours. There will also be some gusty south to southwest
winds during that peak time possibly even advisory level for a few
hours across the coast and valleys and up to 50-60 mph in the
Rainfall rates and amounts with the front may be the highest of
the entire event as we have the best combo of strong upslope flow,
dynamics, and moisture with precipitable waters around 1".
Instability isn`t great with the front but can`t rule out a clap
of thunder or two. Latest HRRR going pretty crazy with hourly
rates close to an inch in SB County with the front. This seems a
bit high but it`s not totally out of the realm of possibility.
More likely peak rates are around a half inch with some isolated
.75/hr in the heavier cells. Minor flows are likely but much less
confident in impactful flows. Will continue to monitor the storm
development and high res model output but for now will hold off
issuing a burn area flash flood watch.
Snow levels will be a little tricky tonight. Warmer air with front
will clash with pre-existing cold air at lower levels so there may
be a brief period of lower elevation snow (4000-5000 feet) with
minimal accumulations before the warmer air kicks up the snow
levels to 6000-7000 feet later on.
The front is expected to exit LA County just before noon
Wednesday followed by some stiff westerly breezes and maybe even
some sunshine before a secondary impulse come in Wednesday night
into Thursday morning. This one is much colder but with about half
the PW with the front. Individual cells will be moving slower as
steering winds decrease with the approaching low but air mass will
be more unstable due to the much colder air aloft. Precip will be
more showery but still potentially quite heavy with graupel or
small hail likely in many areas. Snow levels will fall to around
3000 feet during this time with some light snow down to as low as
2500 in heavier cells. Antelope Valley foothills will likely see
a few inches of snow and possibly even a dusting down to the
Showers with possible thunderstorms will continue through
Thanksgiving evening before decreasing in areal coverage and
intensity Thursday night into Friday. Most areas should see some
sunshine Friday but temps still mostly in the 50s at lower
.LONG TERM (SAT-TUE)...26/143 PM.
Interesting pattern for the weekend into early next week. Weak
ridging will develop over California Saturday, however the next
system isn`t far offshore and it`s tapping into a long fetch of
moisture across the Pacific. The models have been struggling with
the interaction between the trough offshore and the ridge but the
trends appear to be favoring a return of wet weather to at least
SLO/SB Counties by Saturday afternoon. The GFS is weaker with the
ridge and thus allows the precip to advance farther east into
Ventura and possibly even LA Counties. PW`s are quite high, almost
1.5" just off the coast with 30-40kt southwest flow at 850 mb. So
this could prove to be a significant rain maker for the western
part of our forecast area. It`s much warmer given the subtropical
source and weak ridging aloft so this will not bring additional
snow to the area. Main questions are how far east will the precip
get and when and we`ll likely next another couple days to sort
that out. For now pops have been increased area-wide but
especially across SLO/SB Counties with rain likely many areas Sat
and Sun. The GFS pulls back the precip early next week as the
moisture axis shifts west but this could easily change so will
keep pops in the forecast through Tuesday.
At 2330Z, there was no marine inversion at KLAX.
Overall, moderate confidence in 00Z TAF package. High confidence
in CAVU conditions for all sites through this evening with some
scattered smoke possible around KSBA (due to Cave Fire). For
tonight and Wednesday morning, high confidence in rain as cold
front sweeps through. Also high confidence in numerous showers
Wednesday afternoon. However, only moderate confidence in timing
of rain and associated flight category changes.
There is a slight chance of thunderstorms across the Central Coast
after 12Z then after 15Z south of Point Conception.
KLAX...Overall, moderate confidence in 00Z TAF. High confidence
in CAVU conditions through this evening. For tonight and Wednesday
morning, high confidence in light to moderate rain thru Wednesday
morning, and showers Wednesday afternoon and evening, but only
moderate confidence in rain timing (+/- 2 hours of current
forecasts) and associated flight category changes. There is a
slight chance of TSTMs after 15Z. Moderate confidence in gusty
southeast winds about 15Z-19Z.
KBUR...Overall, moderate confidence in 00Z TAF. High confidence
in CAVU conditions through this evening. For tonight and Wednesday
morning, high confidence in light to moderate rain, and for
showers Wednesday afternoon, but only moderate confidence in rain
timing (+/- 2 hours of current forecasts) and associated flight
category changes. There is a slight chance of TSTMs after 15Z.
For the Outer Waters, moderate to high confidence in current
forecast. High confidence in a combination of Small Craft
Advisory (SCA) level winds and seas continuing through Thursday.
On Friday, there is a 50% chance of SCA level winds across PZZ676.
For Saturday and Sunday, high confidence in SCA level winds with a
40% chance of Gale force gusts.
For the Inner Waters north of Point Sal, high confidence in
current forecast. High confidence in combination of SCA level
winds and seas continuing through Thursday. On Saturday and
Sunday, high confidence in SCA level winds with a 30% chance of
Gale force gusts.
For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. High confidence in SCA level
southeasterly winds on Wednesday as cold front sweeps through.
For Thursday and Friday, high confidence in winds and seas
remaining below SCA levels. On Saturday and Sunday, there is a
60% chance of SCA level southeasterly winds across the Santa
A HIGH SURF ADVISORY remains in effect for the Central Coast
through Wednesday night as a large northwest swell will move into
the waters. Surf heights will build to 10-15 feet tonight and
For the coasts of Ventura and Los Angeles counties, a BEACH
HAZARDS STATEMENT will remain in effect through Wednesday
afternoon due to elevated surf (3-6 FT) and strong and dangerous
CA...High Surf Advisory in effect until 3 AM PST Thursday for
zones 34-35. (See LAXCFWLOX).
Beach Hazards Statement in effect through Wednesday afternoon
for zones 40-41. (See LAXCFWLOX).
Winter Storm Warning in effect from 4 AM Wednesday to 4 AM
PST Friday for zones 52>54. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect until 3 PM PST Wednesday for
zones 645-670-673-676. (See LAXMWWLOX).
Small Craft Advisory in effect from 3 AM to 9 AM PST
Wednesday for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect from 3 AM to 3 PM PST
Wednesday for zone 655. (See LAXMWWLOX).
.HAZARD POTENTIAL OUTLOOK (FRI-TUE).
Cold temperatures are likely Friday and Saturday mornings with
widespread frost or freeze conditions possible across the
interior, possibly extending into some coastal valley locations.
Periods of heavy rain possible across SLO/SB Counties over the
Area Forecast Discussion
National Weather Service Memphis TN
832 PM CST Tue Nov 26 2019
First round of convection continues to stream northeastward along
and east of the Mississippi River. The HRRR shows a second round
of convection occurring right along the cold front as it pushes
into the area around 4-5Z. The best instability of the night will
occur just ahead of the front thus can`t say severe threat is
over behind this first round of activity. Will hold onto the
Tornado Watch for now to see what happens as the front gets
closer. Forecast is on track for now, but will need to update
later to clean up evening wording and make some minor tweaks to
.DISCUSSION... /issued 306 PM CST Tue Nov 26 2019/
Warm advection rain showers and isolated thunder spread across
much of the Midsouth this afternoon. Increasing isentropic lift
will allow increasing rain chances through the rest of the day.
Temperature readings are currently sitting in the upper 50`s to
low 60`s with southerly winds 10-15mph and gusts near 25mph. As
the surface pressure gradient tightens ahead of an approaching
frontal boundary, surface winds will continue to increase.
Therefore, a Wind Advisory will be in effect from 4 PM through 6
AM tomorrow morning for the majority of the Midsouth.
An Enhanced Risk for severe weather remains in effect for the
western portion of the CWA with a slight and marginal risk
elsewhere. Winds look to still be the primary threat due to a
strengthening LLJ and increasing shear profiles. There is an
isolated tornado threat due to 0-1km SRH values 450-550 m2/s2.
Rain will exit the Midsouth by Wednesday morning as high pressure
builds back into the region. The majority of Wednesday will be
breezy and cooler with highs in the 50`s.
Warm advection rain showers will filter across the north on
Thanksgiving Day as a shortwave ridge pass across the region.
Long term models are in good agreement regarding an upper low in
the Rockies progressing across portions of the Midwest this
weekend. Similarly, another cold front will move through the
Midsouth on Saturday increasing rain chances. By Sunday rain has
exited the region and cooler temperatures pool into the area.
The remainder of the period looks to be dry and cooler as high
Numerous SHRAs and a few TSRAs expected this evening as a cold
front approaches. Expect MVFR conds with occasional IFR cigs/vsbys
in heavier SHRAs. TSRA coverage has been limited so far due to
the lack of instability so will continue with VCTS wording for
now. Expect the main bulk of precip to start pushing east around
04z at KMEM. Additional development is expected ahead of the
advancing cold front that will push through from 05z-10z followed
by VFR conds. There could be a few TSRAs with this line but not
confident enough to mention attm. Gusty south winds at 15-25 mph
will veer west overnight and then to WNW on Wednesday before
diminishing late in the day.
AR...Wind Advisory until 6 AM CST Wednesday for Clay-Craighead-
MO...Wind Advisory until 6 AM CST Wednesday for Dunklin-Pemiscot.
MS...Wind Advisory until 6 AM CST Wednesday for Benton MS-Coahoma-
TN...Wind Advisory until 6 AM CST Wednesday for Benton TN-Carroll-
Area Forecast Discussion
National Weather Service Mount Holly NJ
928 PM EST Tue Nov 26 2019
As high pressure continues to move offshore, a strong area of
low pressure will move out of the plains and into the Great
Lakes. This storm system will begin to affect our region
Wednesday afternoon as it moves into the Northeast. High
pressure will then build into the region through Saturday,
keeping our weather dry and tranquil. Another strong complex
system is forecast to affect our region Sunday into Monday.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
High pressure located over the western North Altantic will
continue to lose its influence over our weather during the
night. Meanwhile, strong low pressure will move from the lower
Missouri River Valley toward the Great Lakes.
We are anticipating mainly high clouds overnight, with the
arrival of some mid level clouds toward daybreak. The wind
should be light and variable, and there may be some patchy light
Minimum temperatures in our region are forecast to range from
the upper 30s to the middle 40s.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
Wednesday morning as the PV that is out ahead of the main
stacked low exits the coast a weak surface low will form near
Long Island with a warm front bisecting central NJ. Weak rain
will form along and north of the warm front with the best
forcing for ascent more towards central NY in association with
the impressive 500 mb height falls. The best chance of rain
across the area appears to be late morning into afternoon in
association with the PV. Rainfall totals looks to be relatively
low with the coverage being somewhat in question. Latest run of
the HRRR actually has all of the precipitation forming along the
warm front after it has passed central NJ. This appears to be
the outlier though. Overall have kept PoPs at chance for most of
the area (except the western zones) as mid-level dry air looks
to surge east across the area in the afternoon hours. This means
that the precipitation will likely come to a quick end
Wednesday afternoon due to the dry mid-level air and weak
subsidence on the back side of the wave. Wednesday afternoon
into evening the main upper level low will approach from the
west with the pressure gradient rapidly tightening. Latest GFS
forecast soundings support wind gusts of 20 to 25 kts in the
warm sector out ahead of the cold front.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A strong low pressure system will approach the Great Lakes and
Ohio Valley late this week and then weaken as another strong low
wraps up off the coast Saturday into Sunday. Precipitation type
is proving to be extremely challenging as the 12Z runs of the
global models are suggesting a much more intense system with a
coastal low developing near or off our coast. Moisture will be
provided from a feed off the Gulf of Mexico early, then off the
Atlantic as the continental parent low occludes and the new
coastal low overtakes the show. We have placed the likely pops
in the appropriate periods. P-type will remain tricky right up
until the event begins with sleet, freezing rain, and a mix or
rain and snow possible with the initial onset. Mostly rain south
and east with snow and freezing rain possible across northern
NJ and the southern Poconos of northeastern PA. It is far too
early to begin discussing any snowfall totals, but considering
the nature of the developing offshore low, some snow
accumulations across the Poconos and northwestern NJ are
possible later this weekend and into early next week. At this
point, feel that the models may be a little too bullish on the
system but this is complex and dynamic system that is worth
Slow improvement Monday with colder drier air overspreading the
area on gusty north to northwesterly winds. Temperatures be
early next week will be around 5 degrees below normal.
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Overnight...Mainly VFR with high, and eventually mid level
clouds. Some MVFR visibility restrictions are possible toward
daybreak. Variable wind 6 knots or less.
Wednesday...Some MVFR visibility restrictions in the morning,
otherwise VFR with ceilings lowering into the 3500 to 4500 foot
range. Scattered showers in the afternoon that may bring brief
MVFR conditions. Variable wind 6 knots or less, becoming
southwest and increasing to 8 to 12 knots with gusts around 20
knots in the afternoon.
Thursday...generally VFR conditions with strong northwest winds
from 15 to 20 knots and gusts as high as 35-40 knots. A few
light showers or sprinkles are possible, especially at KRDG and
KABE, which may lower restrictions at times. High confidence in
winds, low confidence in visibility/ceiling restrictions.
Friday...VFR conditions expected with north-northwesterly winds
from 5 to 10 knots and gusts to 15 knots. Medium confidence.
Saturday...VFR conditions expected with northerly winds from 5
to 10 knots. Medium confidence.
Sunday...VFR conditions to start the day, turning MVFR as skies
turn overcast. Easterly winds turning northerly, and eventually
northwesterly from 5 to 10 knots as a coastal low pressure
center forms along the NJ Coast. Low confidence.
A light southerly wind is anticipated for tonight. Wind speeds
are forecast to increase on Wednesday, with Small Craft Advisory
level conditions expected in the afternoon, and gale force
gusts around 35 knots possible late in the day. The increasing
south to southwest wind on Wednesday should cause wave heights
on our ocean waters to increase from around 2 feet in the
morning, to 4 to 6 feet late in the day.
Wednesday night into Thursday...winds shifting abruptly from
southwest to northwesterly Wednesday night. Gale force gusts
likely through much of the day Thursday for most of the waters,
thus a Gale Warning has been issued for all of the marine zones
into Thursday evening. Seas remain elevated from 5 to 7 feet.
Friday...SCA conditions likely through Friday morning as
northwesterly winds diminish with the departure of a large low
pressure system. Winds will gust from 25 to 30 knots Thursday
night into Friday morning, then drop below 25 knots near or
after 12Z Friday. Seas dropping from 3 to 5 feet in the morning
to 2 to 4 feet in the afternoon.
Saturday...generally sub-SCA conditions expected with north-
northwesterly winds from 5 to 10 knots and gusts up to 15 knots.
Seas from 2 to 4 feet.
Sunday...generally sub-SCA conditions are expected across all
zones Sunday, though gusts may near or exceed 25 knots for the
southern three Atlantic zones and perhaps over the lower
Delaware Bay as southwesterly winds turn northwesterly. Seas
generally from 2 to 4 feet.
MARINE...Gale Warning from 4 PM Wednesday to 7 PM EST Thursday for
Gale Warning from midnight Wednesday night to 5 PM EST
Thursday for ANZ430-431.
Area Forecast Discussion
National Weather Service Pocatello ID
804 PM MST Tue Nov 26 2019
.UPDATE...Have produced a very minor update to the going forecast
with respect to snowfall probabilities, coverage, and amounts for
the overnight period. Area web cams across the central mountains
showing evidence that some light snow is already beginning to fall
early this evening. Accumulations do not appear to be much so
far, but this does appear to be the early beginnings of the big
event. Satellite imagery shows very well defined low centered over
the coastal border of Oregon/California this evening. Deepest
moisture associated with the low over Eastern Oregon shifting
toward Idaho along with strengthening divergence aloft. More
consistent snowfall still expected to arrive around/after midnight
for most of East Idaho. Wind profiles still favor downsloping
influence over the very southern portions of the Snake Plain in
the populated interstate corridors. GFS however favoring a deeper
southeast flow and stronger veering just off the surface which may
be enough to overcome the downslope effects. HRRR trends also
favor the strongest downslope conditions in the southern Snake
Plain to develop mid Wednesday morning, which leaves several hours
for the snow to develop. Of other concern is the HREF depictions
of the potential for greater than 1"+ per hour snowfall rates
across the central mountains, developing into Clark County/Monida
region late tonight into Wednesday morning as well. Think that the
current snowfall depictions into early Wednesday are generally on
track and thus just made minor adjustments in line with latest
high res model runs. All headlines remain intact for the overnight
.PREV DISCUSSION... /issued 250 PM MST Tue Nov 26 2019/
SHORT TERM...Today through Friday. By late today into tomorrow
models continue to show a significant storm system moving through
the area. Mostly Southerly flow will dominate bringing moderate
to heavy snow to those areas favoring Southerly flow, particularly
the Southeast Highlands, the northern half of the Magic Valley,
the northern half of Snake Plain near Craters of the Moon as well
as the southern half of the Central mountains, Lost River range,
the Lemhi/Beaverhead mountains and the western portions near
Island park. All these areas are currently under a winter storm
warning starting late tonight and going through Thursday morning
for 8 to 12 inches of snow with locally higher mountain amounts of
12 to 18 inches. All other areas with the exception of areas near
Stanley and Challis are under winter advisories as temperatures
look cold enough for snow down low on Wednesday bringing valley
amounts of 1 to 5 inches. The only area that may see a rain/snow
mix will be along I-86 where Southerly down slope will likely
bring warmer temperatures, especially by late morning into the
afternoon. Also, expect breezy to moderate winds mainly in the
morning tapering off in the afternoon where gusts of 25 to 35 mph
are expected, especially for our southwest areas in the Southern
Highlands and the Eastern Magic valley as well as the Snake River
plain and ridgetops. These winds will create blowing and drifting
snow. Expect hazardous driving conditions starting early tomorrow
morning (Wednesday). The heavier snowfall will peak tomorrow
morning to include most valley locations and then continue into
the afternoon focusing on mountains. By Wednesday night into
Thanksgiving day models continue to show upslope areas across the
Southeast Highlands, southern Central mountains, southern Lost
River range, Beaverhead mountains, and Island Park region to
continue to get light to moderate snow into the afternoon and
taper off by mid-afternoon. Colder air starts to move into the
area by late Thursday into Friday.
By Friday morning more moisture starts to move into the area from
the southwest. Expect 3 to 7 inches across upslope areas in
overall Southerly flow again. This time valley locations may see
slightly more snow with 1 to 5 inches expected. Again, the
Stanley and Challis areas will not see much snow. There is a
little more model uncertainty with this system. The GFS models
breaks away from other models as described above and shows the
snow mainly hitting just our extreme southeast and east areas.
Please use extreme caution and adjust driving times if possible.
LONG TERM...Saturday through Tuesday. Looks to be a quieter
period but will still have lingering snow showers in eastern
highlands on Saturday as system exits. Some light snow may return
Sunday ahead of the next system although right now looks fairly
week and not a major storm. For now have at least a slight chance
of snow daily through the extended but as mentioned looks to only
be very light amounts daily and not significant travel impacts.
Temperatures will start off very cold Saturday with a moderating
trend then through Tuesday with high temperatures back to seasonal
normals by Monday and Tuesday.
AVIATION...Expecting poor flying conditions beginning tonight and
continuing through Wednesday. Expect IFR to low IFR conditions at
SUN after 08Z in heavy snowfall through Wednesday. Snow will not
be as heavy at the other three sites but expect low enough
visibilities in snow and low ceilings for MVFR to occasional IFR
conditions at PIH, IDA, BYI and DIJ. Will be very likely for SUN
to go below airport minimums after midnight tonight.
Winter Weather Advisory from 11 PM this evening to 5 AM MST
Thursday for IDZ051>056.
Winter Storm Warning from 5 AM Wednesday to 5 AM MST Thursday
Winter Storm Warning from 11 PM this evening to 5 AM MST
Thursday for IDZ066>069-073>075.
Winter Weather Advisory from 5 AM Wednesday to 5 AM MST Thursday
Area Forecast Discussion...UPDATED
National Weather Service Shreveport LA
927 PM CST Tue Nov 26 2019
The first round of convection has moved east of the forecast area
as the stronger low-level warm air advection has also exited and
instability has diminished. Thus, the tornado threat appears to
have ended, so Tornado Watch #693 was cancelled for all of our
Farther to the west, the next round of showers and thunderstorms
are developing ahead of a cold front that is still west across
Central Oklahoma. An isolated severe storms cannot be completely
ruled out with this line, but it is quite progressive is moving
east rapidly. The individual cells are also quite small, so any
impacts should be short-lived. The latest HRRR suggests this line
of storms will continue to build southwest across Texas and should
make more of a southeastward movement around midnight, especially
as the cold front surges into and across the area, finally exiting
around 10z Wednesday morning.
Overall, very few changes were made to the ongoing forecast. The
biggest update was to remove the mention of severe thunderstorms.
Otherwise, a few minor edits were made to the hourly temperature,
dewpoint, and wind grids. Overnight low temperatures and the PoPs
were left intact.
.PREV DISCUSSION... /issued 620 PM CST Tue Nov 26 2019/
For the ArkLaTex terminals still convective threat with isold
tornadoes for KELD/KMLU for a few hours. Mid level trough is
shifting low level winds and flaring off new cells with MOD
turbulence from climb out with SW 20-50KT by 10kft and SW50-100KT
for flight levels from 100-300 respectively. Storm tops in S AR
and NE LA 35-40kft movg NEat40KT. Expecting fropa overnight to
sweep out low level moisture and few clouds early before bcmg ovc
100 again by 21Z with next impulse in the brisk SW flow aloft.
PREV DISCUSSION... /issued 255 PM CST Tue Nov 26 2019/
SHORT TERM.../Tonight through Wednesday Night/
Latest mesoanalysis showing our best instability axis stretching
from the Lower Toledo Bend Reservoir northward into portions of SC
AR attm. MUCAPE values range from near 2000J/KG near the Toledo
Bend Dam to between 500-1000J/KG closer to the I-20 Corridor of N
LA with values near 500 across SC AR. Likewise, deep layer Bulk
Shear values in the 0-6km layer are on the order of magnitude of
60 to 70kts with 0-3km SRH values ranging between 250-300m2/s2.
So while there is plenty of shear and the instability is trying to
get there, what is missing is upward forcing and a near sfc
trigger for the development of strong to severe thunderstorms.
Looking at the latest upper air analysis, vigorous upper trough
axis is just now entering the Central/Southern High Plains and
will be racing towards the Upper/Mid Miss Valley by late tonight.
Most of the dynamics in association with this trough axis will
remain to our north but we remain borderline with strong to severe
thunderstorms later this afternoon/this evening across our
northern and northeastern most zones still possible. Been
conversing with SPC throughout the day and the likelihood of
severe thunderstorms is far from certain, but more of a
conditional threat if storms can form in the warm sector to our
northeast before we see sfc based instability begin to wane late
this evening into the overnight hours. A strong cold front should
race south and east overnight, entering our northwest most zones
after 9 pm and through all but our southeast most zones by 3 AM
Wed Morning, taking all the precipitation with it. There could be
a narrow line of storms that form on the frontal boundary itself
late tonight but anything that forms on the front will be sub-
Much cooler post frontal temperatures overnight compared to the
prefrontal temperatures we saw early this morning with overnight
lows ranging from near 40 north to the lower 50s southeast.
Kept pops out of the forecast for Wednesday even through we should
begin to see an increase in elevated cloud cover from the west
during the day Wednesday as our flow aloft will remain out of the
LONG TERM.../Thanksgiving Day through Tuesday/
On Thanksgiving Day, the lead shortwave ahead of our next major
upper trough will be transitioning NE from the Big Bend of Texas
across the middle Red River Valley with a surge in Pacific moisture
and a broad area of expanding showers. This convection will be
primarily confined to the NW half of our region, generally along and
north of a line from near Tyler, Texas to Hope, Arkansas. Farther
south and east, rain chances will remain quite low with just very
isolated showers possible through Thanksgiving Day. As a result,
daytime temperatures will vary widely with highs near 50 degrees
across our far NW zones and then ranging through the 50s south to
near the I-20 corridor with lower and mid 60s south of I-20. Rain
chances will continue to remain highest along and north of I-30
through Thursday night into Friday as forcing ahead of the upper
trough will continue to induce showers in the increasing SW flow
aloft. Meanwhile at the surface, a warm front will be returning
northward from the Gulf coast during the day on Friday and provide
increasing instability across much of the region with some embedded
thunderstorms becoming more likely through Friday night ahead of the
upper trough and associated cold front.
By late Friday night into early Saturday morning, the cold front
will be encroaching on our NW zones with showers and thunderstorms
expanding SE along and ahead of the front. Instability ahead of the
cold front will be increasing with MUCAPE values nearing 1000 J/kg
and perhaps slightly higher, especially across the eastern half of
the region where some daytime heating will occur prior to frontal
passage. Shear profiles appear to be quite robust such that a solid
line of strong to possibly severe convection is likely to develop
and spread SE across the region through the day on Saturday. SPC`s
Day 5 convective outlook currently has our entire region highlighted
for Saturday so confidence in the threat of some severe weather does
continue to increase. However, more specific details will come with
better model consensus over the next few days as it relates to exact
timing and severe weather mode. For now, it appears damaging winds
will be the primary threat with isolated tornadoes being a lesser
As the cold front and convection clear the region later on Saturday
night, cooler and drier air will quickly spill across the area with
more seasonable conditions through early next week as we enter the
month of December.
.PRELIMINARY POINT TEMPS/POPS...
SHV 48 63 47 60 / 50 0 20 20
MLU 52 63 44 61 / 70 0 10 10
DEQ 39 57 43 50 / 30 0 30 70
TXK 43 58 43 52 / 40 0 30 50
ELD 46 60 42 56 / 70 0 10 20
TYR 45 61 48 59 / 30 10 30 50
GGG 46 62 47 60 / 40 0 30 40
LFK 51 64 50 67 / 50 0 20 20
Area Forecast Discussion
National Weather Service Tulsa OK
756 PM CST Tue Nov 26 2019
What an evening so far across northeast Oklahoma. Wind gusts
enhanced by a band of showers, some evaporating before they hit
the ground, and along a strong cold front reached 60 to 70 mph
earlier this evening. Coffeyville KS had a gust to 75 mph. The
HRRR seems to have picked up on the signal starting with the 23z
run and onward and suggests that the high wind gust potential will
depart to the northeast by 03Z. At this time, more than likely
the high wind warning will be replaced by a wind advisory and will
run until 06Z. A wind advisory was issued downstream into NW AR
from 03Z to 12Z.
The isolated storm that the HRRR was forecasting for much of the
day developed near Pryor but didn`t mature until it moved into SW
MO where severe and tornado warnings were later issued in that
To top everything off, very dry air is accompanying this front,
and in combination with the strong winds Red Flag conditions are
spreading farther into eastern Oklahoma than earlier anticipated.
It`s rare for this dry of an airmass to push this far east after
dark. Further eastward expansion of the Red Flag warning is
possible this evening.
.PREV DISCUSSION... /Issued 521 PM CST Tue Nov 26 2019/
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Strong low pressure system moving across Kansas this evening will
result in a period of strong west winds with gusts of 30-40 knots
through about 09z. Scattered thunderstorms may impact western AR
TAF sites at the beginning of the forecast period and may result
in brief MVFR conditions. Otherwise VFR will prevail through the
period with winds diminishing and becoming more northerly during
the day Wednesday.
PREV DISCUSSION... /Issued 327 PM CST Tue Nov 26 2019/
Rapidly deepening low pressure system in the Plains is causing
lots of active weather across a large area this afternoon. To our
north and west, a winter storm will bring several inches of snow
along an axis from Nebraska through Minnesota. Surface cold front
is now pushing into far western Oklahoma where dewpoints have
fallen into the single digits/teens and dangerous fire weather
conditions are ongoing.
Very strong surface winds are occurring across western Oklahoma
this afternoon with gusts in the 50-60mph range in some locations.
These winds will spread into northeast Oklahoma and northwest
Arkansas late this afternoon and tonight, with a wind shift to the
west this evening and gusts possible in the 40-45 mph range.
A line of showers and thunderstorms will gradually move out of
western Arkansas late this afternoon. Wind profiles will improve
tonight, but instability has been lacking to support a more
organized severe threat in northwest Arkansas. The higher severe
threat will be across central AR/northern LA. There will be a low
potential for isolated strong storms tonight across northwest
Arkansas, if storms can redevelop as the cold front moves east
and interacts with the better moisture.
On Wednesday, the gradient will relax, with decreasing winds and
high temperatures back in the upper 40s to lower 50s. This day will
be the quieter weather day ahead of the next storm system, which
will begin affecting eastern Oklahoma by Wednesday night.
Widespread cold rain will develop for Thanksgiving Day, with
highs only in the low to mid 40s. A warm front will move back
north into the area on Friday, with surface moisture rapidly
returning. A squall line may develop late Friday into early
Saturday morning, with the potential for severe storms across
eastern Oklahoma and western Arkansas. The rest of the holiday
weekend will dry out on Saturday with highs back in the 60s, with
another cold front arriving by Sunday.
.PRELIMINARY POINT TEMPS/POPS...
TUL 35 50 37 41 / 10 0 60 100
FSM 39 53 40 45 / 30 0 20 100
MLC 36 51 38 44 / 10 0 60 100
BVO 33 50 34 42 / 10 0 50 100
FYV 35 48 36 43 / 40 0 20 100
BYV 35 49 35 41 / 40 0 20 90
MKO 34 50 37 40 / 10 0 50 100
MIO 34 48 34 44 / 20 0 20 100
F10 36 50 37 41 / 10 0 60 100
HHW 38 53 41 48 / 20 10 50 90
OK...Wind Advisory until 6 AM CST Wednesday for OKZ069.
Wind Advisory until midnight CST tonight for OKZ065-066-068-070-
High Wind Warning until midnight CST tonight for OKZ054>064-067.
Red Flag Warning until 9 PM CST this evening for OKZ054>056-
AR...Wind Advisory until 6 AM CST Wednesday for ARZ001-002-010-011.
Area Forecast Discussion...UPDATED
National Weather Service Tucson AZ
849 PM MST Tue Nov 26 2019
.SYNOPSIS...A weather system will bring deep moisture and showers
spreading up from the south Wednesday afternoon and Wednesday night.
Areas of flooding possible southeast of Tucson. A strong Pacific
storm will bring significant valley rain and mountain snow later
Thursday into Friday. Windy conditions and much cooler temperatures
are also expected. Chilly overnight lows to end the week, with warmer
afternoon highs early next week.
.DISCUSSION...Sent a quick update to tweak temps this evening and
POPS later Wednesday into Wednesday evening based on the latest
guidance. The adjustments were upward in nature for the afternoon
into the overnight hours, especially where we had significant QPF
forecast where I jumped the pops solidly into the categorical range.
The pop increase also included the Tucson metro area based on latest
deterministic and short range ensembles. If the trend of shifting the
back edge a bit further west continues, we may need to increase the
pops a bit more. There is likely to be a fairly sharp edge to the
precipitation on the west side Wednesday afternoon and placing that
is a bit tricky. No other tweaks made at this time.
.AVIATION...Valid through 28/00Z.
FEW-SCT clouds at 8k-12k ft MSL, BKN-OVC clouds AOA 20k ft MSL.
Showers spreading in from the south Wednesday with SCT-BKN clouds 8k-
10k ft MSL, brief MVFR conditions possible south of KTUS. SFC wind
wly to nwly at 10-18 kts this afternoon, diminishing overnight. SE-S
winds 10 to 12 kts Aft 27/13Z. Aviation discussion not updated for
.FIRE WEATHER...A good chance of valley rain will be possible from
Tucson south and east Wednesday afternoon, spreading across all of
southeast Arizona Wednesday night into Friday with significant snow
possible in the mountains. The precipitation will then come to an end
from west to east late Friday night into Saturday. Strong and gusty
winds will also occur late Thursday afternoon through Friday. High
winds possible in the mountains and some Cochise County valleys. Dry
and warmer conditions are expected Sunday into Tuesday of next week.
.PREV DISCUSSION... /issued 319 PM MST Tue Nov 26 2019/
A busy pattern this week continues. Our first low has lifted into
the front range of the Rockies with the trailing cold front pushing
through our area earlier this morning. The front is washing out in
northern Mexico, with the HRRR showing higher dew points pushing back
in from the south as early as tonight.
A low off the coast of Baja is guiding much deeper moisture toward
our area over the next 36 hours, with showers spreading in from
the south tomorrow afternoon. Areas of heavy rain will bring some
flooding concerns late Wednesday into Thursday morning. Precip
amounts of 1 to 2 inches across southern Santa Cruz and the
southern half of Cochise county, with isolated higher amounts
possible. Snow levels should generally remain above mountain tops
with this first system.
The final piece of our weather puzzle this week will be a strong
and cold system digging down the west coast over the next 60
hours. Showers will increase in a strong upslope warm sector ahead
of the low late Thursday into Friday morning. Some clearing from
the west late Friday with a few snow showers hanging on in the
mountains Friday night. Snow levels will start to drift lower
Thursday evening, to around 8000 feet initially. A strong cold
front will push snow levels rapidly lower Friday morning,
bottoming out near 5000 feet Friday night. Our best moisture and
precip will correspond with snow levels near and above 7000 feet
just ahead of and with the FROPA. 1 to 2 feet of snow above 7000
feet with up to 3 feet near mountain peaks. Another round of
valley rain as this occurs, with possible flooding concerns in
Strong winds also a concern, with windy conditions by Thursday
evening. High winds in the mountains (up to 50 or 60mph) handled
by the Winter Storm Watch, but we may need a High Wind Watch for
some lower elevations including Cochise County.
This system will push quickly into the central plains Saturday
with a dry westerly flow for most of the weekend. Chilly mornings
will remain, but a warming trend for daytime highs by Sunday.
We could see another system by the middle of next week.
Flash Flood Watch from Thursday morning through Friday afternoon
Winter Storm Watch from Thursday evening through Friday evening
Flash Flood Watch from Wednesday afternoon through Friday
afternoon for AZZ507-508-512-513.
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