Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/16/23
See below for an aviation forecast discussion for the 00Z TAFs.
&&
.SHORT TERM...(This Evening through Thursday Night)
Issued at 228 PM CST Wed Nov 15 2023
KEY MESSAGES:
-Winds continue to increase tonight, Coteau downslope winds around
45 mph.
-Cold frontal passage Thursday morning to bring winds shifting out
of the northwest with gusts 35 to near 50 mph during the day.
-Dry and windy conditions to result in Very High Grassland Fire
Danger Index Values Thursday.
Winds out of the south will increase overnight across the Sisseton
Hills. Peak gusts overnight could top out around 45 for favored
downslope areas between Veblen, Peever, Summit, and La Bolt. While
widespread Wind Advisory levels are not expected at this time, it is
enough to highlight the threat on social media posts.
Expect temperatures to fall into the mid 30s to low 40s by daybreak
Thursday, with the coldest air over north central South
Dakota/closer to the nearing cold front. The dry cold front sinking
southeast across the area Thursday morning will bring increasing
winds out of the northwest. The term dry cold front is typically
enough to spark interest as it tends to result in elevated fire
weather concerns. Wind gusts of 35 to 50 mph are expected, with the
strong winds over central South Dakota through the early afternoon
hours. As a result, a Wind Advisory has been posted for much of
central SD Thursday. The Grassland Fire Danger Index Values will be
in the Very High range Thursday. While most locations can expect
relative humidity values to fall into the 40 to 50% range, our
southwestern most counties will be closer to 35%. We will continue
to highlight fire weather concerns in our HWO and through social
media.
Despite the passage of the cold front, temperatures Thursday will
still top out in the 50s (5 to 15 degrees above normal for this time
of year). The small area of high pressure will quickly dig in behind
the cold front and be over western and central SD by 06Z Friday,
before residing over central NE and southeastern SD by 12Z. The
coldest air of around -4 to -6C air at 850mb will be overhead at
around 03Z, with warm air advection already taking hold of all but
our eastern counties by the end of the period. Surface temperatures
Thursday night/Friday morning will fall to around 20F.
.LONG TERM...(Friday through Wednesday)
Issued at 228 PM CST Wed Nov 15 2023
Key Messages:
- Above normal temperatures continue through the upcoming weekend
with dry conditions persisting.
- Uncertainty remains in forecast details for early next week with
respect to precip chances.
The beginning of this period continues to look rather tranquil. Sfc
high pressure is progged to be centered off just to our south and
southeast Friday morning. This high is forecast to drift east away
from our area during the day. A tightening pressure gradient between
this high and a sfc trough north of our area will lead to gusty west
to southwest winds by the afternoon. The higher elevations of the
Sisseton Hills and the favored downslope areas could see the
strongest gusts between 30-40 mph. Winds will slacken by Friday
night as an upper ridge is progged shift overhead for the start of
the upcoming weekend. A warm air advection pattern develops and
helps to usher in some relatively warmer air. Daytime temperatures
this upcoming weekend look to be back in the 50s to perhaps near 60
degrees in some spots. This is about 10-15 degrees above normal for
this time of year.
By the end of the weekend into early next week, some changes in the
pattern look to begin to show up. This is where the uncertainty lies
as deterministic and ensemble guidance continues to disagree on the
strength and placement of an upper trough across portions of the
Plains. This remains evident in the latest Cluster analysis that has
trouble dealing with the split flow pattern and the eventual
evolution of the upper trough. The deterministic GFS remains the
drier solution while the EC/Canadian are the more wet solution.
Their respective ensemble solutions continue to show their own
varying solutions as well. So, will continue to stick with the
inherited in house NBM PoPs that paint basically a 20 to near 30
percent chance for rainfall across our southern and eastern zones by
Sunday night through the first half of the day on Monday. There`s
somewhat better confidence in that a cooler air mass will eventually
win out by the end of the period. A cold frontal passage or perhaps
2 fropas will be possible by the middle of next week. Just how cool
remains a question mark, but cooler readings than what we`ve
experienced look to return. This forecast area could see
temperatures back closer to normal by next Tuesday and Wednesday. By
then, average highs are in the upper 30s to low 40s and average lows
are in the upper teens to low 20s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 524 PM CST Wed Nov 15 2023
Terminals KABR,KATY,KPIR,KMBG
While VFR ceilings and visibility will continue over the next 18
hours, winds will be the main concern. Southerly winds tonight
will shift to the northwest during the day Thursday as a strong
cold front sweeps across the area. Winds will increase with gusts
of 35-45kts prior to 18Z. At this point, the strongest winds are
expected at KMBG and KPIR, with 30-40kts possible at KABR and
KATY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 8 AM to 2 PM MST Thursday for SDZ003-015.
Wind Advisory from 9 AM CST /8 AM MST/ to 6 PM CST /5 PM MST/
Thursday for SDZ004-005-009-010-016-017-033>037-045-048-051.
MN...None.
&&
$$
UPDATE...Dorn
SHORT TERM...KF
LONG TERM...Vipond
AVIATION...Dorn
Area Forecast Discussion
National Weather Service La Crosse WI
559 PM CST Wed Nov 15 2023
.DISCUSSION...(This evening through Wednesday)
Issued at 224 PM CST Wed Nov 15 2023
Key Messages:
- One last unseasonably warm day Thursday, but strong south winds
will gust 40 to 45+ mph, highest across southeast Minnesota.
- Cooler, more seasonable temperatures for Friday and beyond,
with limited precipitation chances expected through the
beginning of next week.
Tonight-Thursday:
Pleasant fall weather prevails this afternoon across the Upper
Midwest with mostly sunny skies and light winds thanks to weak
surface high pressure. The ridge will pass east tonight as
increasing return southerly flow begins to develop ahead of a mid-
level trough and associated cold front approaching from the northern
plains. Despite some increase in mid/high clouds during the day on
Thursday, 925 mb temps look to climb to 12-14C ahead of the front
with favorable south/southwest winds, likely supporting highs into
the 60s, potentially even upper 60s/near 70 in a few spots, if cloud
cover remains thin enough.
Other than the warm temps, winds will be the primary concern on
Thursday. Ahead of the front, RAP soundings and the HREF indicate a
50-60 kt low-level jet developing through the day. The HREF
continues to show high probabilities (50-70%+) for 45 mph gusts
along the low-level jet axis from northern Iowa and southeast
Minnesota through west-central Wisconsin, with the strongest signal
across southeast Minnesota during the early afternoon. Ultimately,
the degree of mixing will impact gust potential, though. The RAP
shows mixing to near 850 mb by afternoon at KRST with gusts up to 50
mph, while the NAM is more muted in mixing (up to 900 mb) with
somewhat lower gusts. If the deeper mixing is realized, dependent
somewhat on clouds, gusts of 40 to 50 mph are probable, highest for
open areas of southeast Minnesota and far northern Iowa. Coordinated
with WFO Des Moines/Twin Cities for a wind advisory for the more
unsheltered wind prone areas of southeast Minnesota and northeast
Iowa, although winds will be gusty region-wide.
Friday & This Weekend:
Conditions will be noticeably different by Friday as temperatures
will drop back to reality to end off the week. With the passage of
an upper-level trough through our region into Friday, some vorticity
advection associated with the trough axis will instigate a surface
boundary that will push through the region overnight Thursday. While
the lift from the associated frontogenesis is fairly strong, limited
moisture with the 850mb moisture transport nose centered across
northern Wisconsin into the Upper Peninsula of Michigan suggests
that ambient moisture will be used to saturate the column rather
than precipitate. As a result, generally not expecting much in
the way of precipitation for our area Thursday night and Friday,
with only slight chances in our extreme eastern counties.
Temperatures will drop back to seasonable for Friday. Sadly, for
those who are not cold weather fans, upper 30s to lower 40s is close
to seasonable as climatological normals for high temperatures at La
Crosse is around 43 degrees for this weekend. Overnight lows Friday
into Saturday morning will likely drop down below freezing for most
locations. The weekend will feature a slight increase in
temperatures with upper-level ridging and weak warm air advection
will see temperatures increase into the upper 40s to lower 50s
with the 15.12z grand ensemble (GEFS/EC ens/Canadian ens)
generally has an inter-quartile range of 48 to 53 degrees with a
median of 51 degrees for high temperatures for Sunday.
Early Next Week:
Looking ahead next week, early indications suggest that temperatures
will continue to decline further with continued limited
opportunities for precipitation through the early part of next week.
The next chance for any precipitation would come in part due to an
upper-level trough that deterministic guidance shows swinging
through the region Tuesday. Ensemble guidance really backs off on
significant QPF with this system as both the 15.00z GEFS and EC
ensembles have only moderate confidence (30-60% chance) of seeing
0.1" of precipitation with this system. Regardless, temperatures
in the 15.12z grand ensemble (GEFS/EC ens/Canadian ens) show a
clear downward trend with the inter-quartile range in high
temperatures for Thanksgiving being between 24 and 35 with a
median of 31 at La Crosse.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 600 PM CST Wed Nov 15 2023
Whilst VFR conditions expected across the forecast area from
southeast Minnesota, northeast Iowa, and western into central
Wisconsin, a period of high winds and an accompanying low level
jet expected to result in LLWS. Similar to previous forecasts,
have continued for both KRST & KLSE although surface gusts may
limit actuality. While model guidance tends to lean into LLWS
more often than observed, it is quite quick to remove it Thursday
night. Instead, have continued through much of the 16.00Z
forecast period. Off deck increased winds expected to traverse
from northwest to southeast through Thursday evening. Therefore,
have removed at KRST at 16.20Z, but will be something to keep an
eye on. Lower valleys, such as KLSE, are more likely to experience
decreased surface winds and therefore higher likelihood to
experience LLWS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...Wind Advisory from 9 AM to 7 PM CST Thursday for MNZ079-086-087-
094-095.
IA...Wind Advisory from 9 AM to 7 PM CST Thursday for IAZ008-009-018-
019.
&&
$$
DISCUSSION...JM/Naylor
AVIATION...JAR
Area Forecast Discussion
National Weather Service Charleston SC
902 PM EST Wed Nov 15 2023
.SYNOPSIS...
An area of low pressure will move up the coast Thursday into
Friday, then a cold front will move through late Saturday. High
pressure will build in early next week, then a cold front will
move through late Tuesday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
The 16/00z KCHS RAOB showed the airmass along the middle South
Carolina coast has moistened up a bit since this morning, but a
rather pronounced dry pocket remains centered around 700 hPa.
Showers that moved onshore near Awendaw and McClellanville right
around 7 PM dropped a few hundredths per several mesonet
observations, so the influence of the dry air across the
Charleston Tri-County is waning. Overall, the forecast
philosophy has not changed much from the early evening update
with widespread light rains expected to remain across Southeast
Georgia into far southern South Carolina where Q-G forcing and
isentropic ascent are the greatest. Near term pops were adjusted
slightly to delay rainfall refocusing off the Savannah River
Entrance by a few hours per latest H3R and RAP trends.
16/01z surface analysis placed 1007-1008 hPa low pressure over
the northeast Gulf of Mexico with a strong wedge of high
pressure nosing down across the Southeast States. A variety of
forcing mechanisms are at play this evening ahead of a strong
southern stream trough centered along the north/central Gulf
Coast which is well displaced from the main belt of the
westerlies. Modest (mostly low/mid-level) Q-G forcing coupled
with multi-surface isentropic ascent atop the inland wedge is
generating a large area of light rain across Southeast Georgia
which is slowly working into southern South Carolina where
abundant dry air is still noted on RAP soundings. While some
additional moistening of the column is expected over Southeast
South Carolina overnight as the main area of rain shifts to just
offshore the Savannah River Entrance, northern parts of
Colleton, Dorchester and Berkeley Counties may very well remain
dry through the overnight period as incoming light rain fights
the extensive dry air in place. Elsewhere, the risk for light
rain will continue this evening and spread into far southern
South Carolina as the best juxtaposition of the various forcing
mechanisms shifts to the Georgia coast.
Observations across Southeast Georgia show rain continues to
accumulate slowly, averaging just a few hundredths or so per
hour. Some increase in rainfall rates could occur along parts
of the coast, mainly near Tybee Island and Hilton Head overnight
as the activity tends to become a bit more convective in
nature. Pops near 90% were maintained across Southeast Georgia
into the South Carolina counties adjacent to the Savannah River,
including Beaufort. Charleston County into coastal Colleton is
still a bit of an unknown with most of the guidance showing the
bulk of the activity remaining just to the south, but it could
be close, especially as daybreak approaches. Further adjustments
may be needed later this evening. Lows from the lower-mid 50s
well inland to the lower-mid 60s at the beaches look on track.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Weak high pressure will remain centered north of the area
Thursday into Friday while a surface low moves north well
offshore. Moist isentropic ascent will continue Thursday and
Thursday night, bringing occasional rain showers to the area. On
Friday, weak NVA aloft and low-level drying should decrease
precipitation coverage as the day wears on. A potent upper
shortwave will push a cold front through the area Saturday
afternoon, but a lack of appreciable moisture and forcing should
maintain dry conditions.
Thursday highs will range from the upper 60s to lower 70s,
while Friday and Saturday will top out in the low to mid 70s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Dry high pressure will settle over the area Saturday night
through Sunday night. A developing upper trough will move east
Monday and Tuesday, bringing low pressure and a cold front
through the local area. Fairly good coverage of rain showers is
expected Monday night and Tuesday.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
16/00z TAF Discussion:
KCHS/KJZI: Wedge conditions will persist with cigs holding VFR
through much of the period. Shower activity will begin to
increase a bit later this evening and especially overnight as
low pressure meanders over the northeast Gulf of Mexico. While
the risk for showers will be greatest at KJZI overnight, any
shower activity will remain quite light and have little impact.
KSAV: Light rain will persist at the terminal overnight as wedge
conditions hold and low pressure meanders over the northeast
Gulf of Mexico. Rain should remain light with little, if any,
reductions in vsbys expected. Cigs are expected to lower to MVFR
this evening and while there is a low probability that a brief
period of high-end IFR cigs could occur just before daybreak,
the risk for these conditions looks to low justify a mention at
this time. Once MVFR cigs set in, they are expected to hold
through the remainder of the 00z TAF period.
Extended Aviation Outlook: An area of low pressure will bring
occasional flight restrictions through Friday night. A cold
front will move through on Saturday, followed by prevailing VFR
through Sunday night. Flight restrictions are possible Monday as
low pressure approaches from the west and rain showers
increase.
&&
.MARINE...
Tonight: Impressive pinching of the pressure gradient between
Hilton Head and Tybee Island has produced near gale force gusts
for the past several hours. The gradient should relax a bit
overnight, but winds were nudged up to a solid 25 kt with gusts
to 30 kt in the Edisto Beach-Savannah nearshore leg with the
late evening update with 20 kt with gusts to 30 kt elsewhere.
Seas will average 4-6 ft nearshore waters and 6-8 ft in the
Georgia offshore waters. Winds have diminished enough in the
Charleston Harbor the cancel the Small Craft Advisory there.
Flags remain in force for all remaining legs due to a
combination of hazardous winds and seas above Small Craft
Advisory criteria.
Thursday through Monday: A moderate NE gradient will persist
Thursday through Friday as high pressure remains inland while
low pressure moves north well offshore. Winds will turn to the
NW late Saturday behind a cold front, allowing seas to slowly
subside. The Small Craft Advisories for 6 ft seas will finally
drop off at varying times Saturday for the nearshore waters and
late Sunday afternoon for the GA offshore waters. Fairly quiet
conditions then expected through early next week, though a
strong southerly flow will develop Tuesday ahead of a cold front
and advisories are possible.
&&
.TIDES/COASTAL FLOODING...
Strong northeast to east-northeast winds will continue through
Friday morning, maintaining the ongoing elevated tidal anomaly.
Minor coastal flooding will be possible with the morning high
tide along the Charleston and Colleton County coasts Thursday
and Friday morning.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 6 PM EST Saturday for AMZ350.
Small Craft Advisory until noon EST Saturday for AMZ352-354.
Small Craft Advisory until 6 PM EST Sunday for AMZ374.
&&
$$
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
634 PM EST Wed Nov 15 2023
.AVIATION...
Simply some pockets of high based cloud through the daylight period
Thursday, as a very dry low level environment continues to govern
conditions. Brief window for shallow fog development toward daybreak
at FNT/MBS, but confidence in occurrence too low to highlight attm.
Winds from the south turning modestly gusty at times Thursday.
Strengthening wind field just off the surface will introduce a
period of low level wind shear Thursday night.
.DTW THRESHOLD PROBABILITIES...
* None.
&&
.PREV DISCUSSION...
Issued at 245 PM EST Wed Nov 15 2023
DISCUSSION...
Extremely dry airmass in place over southeast Michigan, as the 12z
DTX sounding came in with a PW value of 0.09 inches/27 percent of
normal, with 49 C dew pt depressions at both 925/850 MB levels. Thus,
no surprise with the dry/washed out front tracking through the
Central Great Lakes today. The dry low level air will continue to be
conducive for wide diurnal swings, and will skew the mins tonight
toward the colder guidance. With the long night and some elevated dew
pts due to the moisture flux from Lake Michigan, there is some
concern for fog north, mainly north of M-59. With support from
HRRR/NAM and the Rap to a certain extent, adding fog to the forecast.
Could end up just with a hard frost on the ground with the shallow
moisture however.
A renewed surge of warm air advection will arrive on Thursday as
a potent shortwave trough tracks through Central Canada/extending
south into the northern plains. Southwest low level jet progged to
increase to 50+ knots by days end, but boundary mixing depths will
be limited/short of this jet core. Gusts of 25-30 mph appear likely,
with the potential to do 35 MPH or little better across Saginaw
Valley. Based off today`s temps and upstream values, still feel
confident in high temperatures in the mid 60s, real close to the
warmer Euro mos guidance.
Deeper moisture (PW > 1") coming out of the Eastern Gulf Coast
states will attempt to meet up with the cold front Thursday night-
Friday over the Central-Eastern Great Lakes. Model consensus suggests
the deeper moisture will be just off to our east. None-the-less,
with the low level convergence/fgen with the strong cold front, still
would expect us to grind out some light rain showers Friday morning.
Euro remains one of the more aggressive solutions, with a weak
surface reflection riding along the front, supporting widespread
rainfall amounts around a quarter of an inch. The hourly temperature
forecast for Friday is very difficult with the timing of the
front/cold advection considerations through the day.
500 MB trough axis to slide through the Central Great Lakes around
midnight Friday, with a solid shot of cold air, as 850 MB temps
lower into the negative low to mid single numbers. Subsidence and
drying is overwhelming, and no concerns for snow showers. Pronounced
surface ridge in place Saturday morning with modest warming advection
during the day. For the second half of the weekend, models have
trended farther east with the next trough/cold front dropping
southeast from northern Ontario, and bulk of the cold air (-8 C or
colder at 850 MB) now progged to move through the Eastern Great
Lakes. Still, with the strength and areal coverage of the departing
high pressure center over/near Georgian Bay, Monday should remain dry
before the developing low pressure system moves into the Ohio Valley
River Valley Monday night-Tuesday.
MARINE...
Winds continue to relax this evening as the weakening cold front
works across the central Great Lakes. A diffuse ridge quickly slides
overhead tonight maintaining a brief period of lighter flow and
quieter marine conditions. A stronger cold front then begins to drop
through the Great Lakes Thursday resulting in rapid strengthening of
the local pressure gradient. To what degree winds manage to increase
to depends greatly on the magnitude of warm air advection in advance
of the front Thursday. Model guidance continues to suggest that the
near surface layer remains warm/stable enough to greatly limit
mixing down of stronger flow aloft hampering gale potential. While a
sporadic gust to entry-level gales can`t be completely ruled out
late Thursday night, confidence is still too low for a sufficient
magnitude and duration to warrant a headline over central Lake
Huron. Front sweeps across the area Friday morning setting up
moderate to strong northwest flow in its wake. Gusts up around 30kts
are possible through Friday afternoon over northern Lake Huron
however, currently, the gradient looks to weaken quickly enough to
prevent winds strengthening to NW gales.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....MR
DISCUSSION...SF
MARINE.......KDK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Flagstaff AZ
849 PM MST Wed Nov 15 2023
.SYNOPSIS...Tonight, a more active weather pattern begins
bringing cooler and more unsettled weather with rain showers at
times through the coming the weekend.
&&
.UPDATE...Overcast sky coverage has developed across northern
Arizona this evening with increasing low-level clouds. According
to current radar, rain showers have moved into southwestern
Arizona as well as Mohave County with widespread coverage
continuing across southern California. The lightning activity from
earlier this afternoon across southern California and the northern
Baja, has subsided this evening indicating decreasing
instability. However, hi-res models (HREF, SREF, HRRR) continue to
show a decent push of sub-tropical moisture from the southwest
with assistance from some upslope flow, resulting in scattered
rain showers with greatest chances along and west of I-17/US-89
and into the Navajo Nation. Much of this activity should take
place after 11 pm MST tonight and last through early Thursday
morning.
Temperatures overnight are forecast to be well above average
thanks to the increasing moisture and cloud cover. The forecast
low temperature for Flagstaff Airport tonight is 42 degrees which,
if this were to happen, would break the highest minimum
temperature of 39 degrees set back in 2008 for November 16th. We
shall see. Winds will generally be light overnight, under 10 mph,
with occasional breezes from the south-southwest.
The rain showers let up by Thursday afternoon into Friday with
chances returning Friday night into Saturday. The forecast remains
on track with no significant changes needed at this time.
&&
.PREV DISCUSSION /420 PM MST/...High clouds continue to stream
northeastward into the state this afternoon, well ahead of a low
off the west coast. Clouds are thin enough to allow plenty of sun
to pass through so temperatures are running close to 10 degrees
warmer than normal for this time of year. Later tonight through
Thursday morning - a subtropical moisture plume is forecast to
move over the region. There is a large area of rain and
thunderstorms associated with this plume this afternoon moving
into southern California. The moisture will combine with some
upward motion from a disturbance to bring areas of light rain. The
best chances will be from around Flagstaff north and west. Most
areas will only see up to a tenth of an inch of rain, though some
orographic effects could help the Kaibab Plateau and areas around
the Grand Canyon receive 0.20-0.35". After this disturbance and
moisture shift east of the area by Thursday afternoon, mostly dry
and mild weather is expected through Friday afternoon. The HRRR
and other hi-res models still show some scattered QPF during this
time, but looking at forecast soundings the moisture seems too
shallow for much activity, so we adjusted the NBM PoP down a bit.
Friday night through Saturday - model guidance is in good agreement
that the Pacific low will weaken and move across our region as an
open wave. Upward motion will combine with another increase in
moisture for a 50-80% chance of showers. There is still uncertainty
regarding rainfall amounts with the EC and its ensemble members
still on the wetter side and GFS drier. Our forecasts use the WPC
QPF which is a blend, and has totals from 0.20-0.40" along/south
of the Mogollon Rim and less than 0.20" to the north. Snow levels
are forecast to be high enough that any snow accumulation should
be above 8500 feet or so on the San Francisco Peaks and Kaibab
Plateau.
Following the weekend system, another shortwave is forecast to
dive southward through the Rockies with most guidance taking it
east of our area. This is a favorable pattern to get cold
northeasterly winds, with gusts in the 30+ mph range possible
mainly on Monday along/south of the Mogollon Rim. Briefly below
normal temperatures are forecast Monday before ridging takes over
from the west with a warming trend toward the middle of next week.
&&
.AVIATION...Thursday 16/00Z through Friday 17/00Z...MVFR vis and
cigs will be possible in widespread SHRA after 06Z, mainly along
and north of a KPAN-KRQE line. Isolated TS will also be possible
near and around KPRC/KFLG. Conditions begin to improve after 16Z,
with isolated to scattered coverage expected thereafter. Winds
S/SW 5-10 kts with localized gusts 15-20 kts over the higher
terrain.
OUTLOOK...Friday 17/00Z through Sunday 19/00Z...MVFR conditions
will continue to be possible in isolated SHRA through 06Z
Saturday, with more widespread SHRA expected there after. S/SW
winds 5-10 kts for Friday, becoming W 10-20 kts with gusts 20-30
kts on Saturday.
&&
.FIRE WEATHER...Tonight through Friday...Scattered rain showers
develop tonight and into Thursday morning. More isolated coverage is
expected from Thursday afternoon into Friday. South/southwest winds
10-20 mph each day.
Saturday through Monday...Scattered to widespread rain and high-
elevation snow is expected Saturday, with showers lingering into
Sunday. Southwest winds 10-20 mph on Saturday, becoming northwest on
Sunday. Colder and drier conditions then return on Monday, along
with north/northeast winds 20-30 mph.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
PUBLIC...LaGuardia/JJ
AVIATION...Humphreys
FIRE WEATHER...Humphreys
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Blacksburg VA
900 PM EST Wed Nov 15 2023
.SYNOPSIS...
High pressure overhead shifts east through Thursday night. A
front enters the mid-Atlantic by Friday night. Cooler weather
arrives for the weekend.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 900 PM EST Wednesday...
Made some minor adjustments in temperatures for this evening
into tonight. Also modified cloud cover with latest model
solutions for tonight into Thursday. Shaped smoke area with
latest HRRR for this evening into tonight.
Previous:
As of 603 PM EST Wednesday...
High pressure across our region will slide east tonight into
Thursday. Made some minor adjustments in temperatures for this
evening into tonight utilizing the latest surface obs, their
trends and blended into continuity which was colder than NBM.
More changes later...
Previous Discussion:
As of 1203 PM EST Wednesday...
Key Message:
1. Clearing through tonight with seasonal temperatures
Cloud cover will erode as we head through this evening. High
pressure will keep the region dry through Thursday. A few low
to mid clouds could start tracking northward Thursday ahead of
the next front. Through this evening, smoke from the wildfire in
northern Bedford County will stretch northward toward Lexington
and the I-81 corridor. So those from the James River north
toward the Alleghanys will likely see and smell smoke into early
evening.
Forecast confidence is high.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 1215 PM EST Wednesday...
Confidence is high for a cold front to bring light rain by late
Friday, and a breezy northwest flow follows on Saturday.
As high pressure departs offshore on Thursday night, a low pressure
system will track just off the East Coast. However, this system
should stay well to the east and provide subsidence across the
Piedmont. A cold front should approach the Ohio River Valley on
Friday before reaching the Appalachian Mountains by Friday night.
Thus, Friday looks mainly dry with highs in the 50s and 60s, but
light rain should arrive during Friday night. The moisture will
struggle to cross the Blue Ridge due to the aforementioned
subsidence, so rainfall amounts will vary from just a tenth of an
inch east of the Blue Ridge to a half an inch along the higher
elevations of southeast West Virginia.
A breezy northwest flow should follow behind the cold front on
Saturday, and any leftover rain showers should vanish in the
mountains by the afternoon. As cold air advection continues, there
is a chance that the leftover rain showers could briefly switch to
snow along the higher peaks of western Greenbrier County before
dissipating. The wind should relax by Saturday night as high
pressure builds eastward into the Mid Atlantic. Temperatures should
fall into the 20s and 30s during Saturday night with more ideal
radiational cooling taking place.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 1215 PM EST Wednesday...
Confidence is moderate for dry weather on Sunday, but a cold front
may provide widespread rainfall by Tuesday.
High pressure will bring dry weather on Sunday, but it should drift
eastward towards the coast by Monday. Clouds should increase as a
potent cold front reaches Tennessee. The models are not quite
consistent with the timing of this front, but it appears promising
that rain could arrive from the southwest sometime on Monday night
and spread across the Mid Atlantic by Tuesday. There is a chance
that some of the rain may briefly mix with light snow during early
Tuesday morning in the higher elevations of Bath and Greenbrier
counties, but temperatures should climb above freezing to change any
frozen precipitation over to just rain later in the morning.
The passage of this cold front on Tuesday provides the best hope in
quite a while for any beneficial widespread rainfall to alleviate
the ongoing drought conditions. While it is too early to predict any
rainfall amounts at this time, Tuesday does appear to be cloudy and
wet throughout the day. Once the cold front exits on Tuesday night,
the wind will increase from the northwest and become breezy by
Wednesday. Upslope rain showers across the higher elevations of
southeast West Virginia may mix with snow showers as cold air
advection persists through the remainder of the day.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
As of 630 PM EST Wednesday...
VFR conditions are expected through Thursday with high pressure
in place. Periods of high clouds are expected tonight into
Thursday.
Winds mainly light/variable.
High confidence in the ceilings,visibilities and wind during the
taf period.
Extended Aviation Discussion...
VFR conditions expected into early Friday before low level
moisture increases ahead of a cold front. Sub-VFR ceilings with
showers possible Friday into Friday night mainly along/west of
the Blue Ridge, with improving conditions by Saturday afternoon.
A period of dry weather over the weekend into Monday before
another system arrives Tuesday with a better chance of rain and
low cigs. Rain showers may linger in the west on Wednesday.
&&
.FIRE WEATHER...
As of 743 PM EST Wednesday...
High pressure will slowly shift east tonight into Thursday.
Good RH rebound is expected overnight, but RH values will become low
again Thursday afternoon. Minimums will generally be in the 20s and
30s. Winds are expected to remain light tonight and Thursday.
Burn bans or burn restrictions are in effect for many counties.
Consult your local Forest Service or Department of Forestry for
these guidelines.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...WP
NEAR TERM...KK/WP
SHORT TERM...PW
LONG TERM...PW
AVIATION...KK/WP
FIRE WEATHER...KK/SH
Area Forecast Discussion
National Weather Service Tulsa OK
913 PM CST Wed Nov 15 2023
...New SHORT TERM...
.SHORT TERM...
(The rest of tonight)
Issued at 909 PM CST Wed Nov 15 2023
Low level moisture is starting to increase this evening, and this
is likely to lead to the development of low clouds and/or fog in
many areas late tonight into Thursday morning. The HRRR is showing
some potential for dense fog, especially across the western part
of the forecast area, but with a light south to southeast breeze
continuing, not sure how widespread any dense fog will be. For
now, will keep the patches/areas of fog we have in the current
weather grids as is. Overnight low temperatures appear to be on
track at this time.
&&
.LONG TERM...
(Tonight through Wednesday)
Issued at 159 PM CST Wed Nov 15 2023
Above normal temps will continue Thursday with increasing winds
from the south as a cold front approaches. Fire weather will be
limited to some degree by both rising dew points and an overall
increase in cloud cover, but a limited to elevated threat should
exist across much of northeast OK, in particular the drought-
stricken corridor north of roughly Bartlesville to Pawnee. Front
passage Thursday night into Friday may force a a band of very
light showers, but only a slim chance of anything measurable. This
will also bring a modest cool down into the weekend along with a
period of gusty north winds on Friday.
Upper trough is expected to move into the Southern Plains by
Sunday with rain chances spreading eastward during the day Sunday.
Shower chances are expected to linger into Monday night at east
as a closed low develops over the region and slowly drifts east.
Right now the overall rain totals appear to be on the lighter
side, with the possible exception of southeast OK where some
embedded thunder may enhance rainfall amounts. Overall
probably of 1 inch or more through the period Sunday-Monday
remains less than 30%.
&&
.AVIATION...
(00Z TAFS)
Issued at 603 PM CST Wed Nov 15 2023
A few changes were added to the 00z TAF package. Latest guidance
indicates some light fog and MVFR/IFR ceilings developing after
midnight tonight, mainly affecting NE OK. Added a TEMPO group for
KBVO, KTUL, and KRVS for light fog and low ceilings around sunrise
Thursday. The SREF also indicates 70-80% probabilities of
ceilings lower than 3000 feet developing early-mid Thursday
morning across southeast OK and western AR. Added MVFR ceilings
at all 4 AR terminal sites and at KMLC, mainly between 4-9 AM
CST. Dense fog is not anticipated at this time and whatever
fog/low ceilings exist should dissipate and/or lift by 9-10 AM CST
as southerly wind speeds begin to increase and mix-out the
boundary layer. Intermittent MVFR/VFR ceilings are possible
through midday before VFR prevail during the afternoon hours.
However, a few models do have MVFR ceilings remaining intact
through mid-afternoon at the AR terminals where wind
speeds/boundary layer mixing may not be as strong.
Mejia
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 46 69 51 63 / 0 0 0 0
FSM 47 70 54 70 / 0 0 10 10
MLC 46 69 54 68 / 0 0 0 0
BVO 41 70 46 63 / 0 0 10 0
FYV 42 68 50 66 / 0 0 10 10
BYV 44 69 53 65 / 0 0 10 10
MKO 45 68 52 66 / 0 0 0 0
MIO 44 68 50 62 / 0 0 10 10
F10 44 68 51 66 / 0 0 0 0
HHW 48 68 53 70 / 0 0 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...05
LONG TERM....14
AVIATION...67