Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/24/16
Area Forecast Discussion
National Weather Service Albany NY
949 PM EDT Sun Oct 23 2016
.SYNOPSIS...
Conditions will remain brisk and chilly through early in the week.
The storm that brought the rain and snow to the area will continue
to slowly move away from the region. In the meantime, a weak
low pressure system over the Great Lakes region will move
southeastward to the coast bringing some light rainfall to areas
mainly south of Interstate 90 overnight. Higher pressure will
gradually build in from the west through mid week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Forecast update coming for batch of rain moving into western
Mohawk Valley. This looks more ominous on radar than it is. Wet
bulb zeros are running in the 4000-5000 ft range in this area. So
some bright banding evident on TYX radar. Have updated forecast
to chance pops for the western CWA for the next couple of hours.
HRRR shows that this batch of precip weakens with time.
Winds have diminished quickly here this evening with only AQW
showing any gusts above 20 mph. Winds will settle into the 5 mph
range for the rest of the night. A public information statement
was issued at 644 pm with the latest peak wind speeds.
A short wave over the western Great lakes region will move
southeastward toward the coast passing just to the southwest of
the local area. A weak surface low and cold front are associated
with the short wave and will bring some rain showers to areas
mainly south of I-90 for a few hours overnight.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Brisk and gusty conditions will persist with cyclonic flow across
the region on the backside of the stacked low pressure system.
Additional short waves will rotate about the system slowly its
departure. At the surface, high pressure will build southward out
central Canada across the Great Lakes region and its will gradually
shift eastward. In the meantime, the upper ridge over the central
CONUS will shift eastward also. The low level flow should be
northerly enough to keep the lake effect showers to our west
across central New York however they could extend into portions of
the eastern Catskills. Overall temperatures will run below normal
especially on Tuesday.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
In the mean, the period will feature a trough across the eastern
U.S. with ridging through the Rockies, with fairly quick flow across
the northern tier.
As for specifics, Wednesday will be generally dry and cold as strong
high pressure slides across the area. Temperatures will average
around 10 degrees below normal.
Models in good agreement tracking a low through the Great Lakes and
up the St. Lawrence Valley for Thursday/Thursday night. This brings
a general 0.50-1.00 inch precipitation event to the region.
Temperatures start out cold on Thursday morning. Right now timing of
precip into the CWA looks to hold off until temperatures warm on
Thursday. If precip gets here earlier, we could be looking at some
type of wintry mix. Eventually with the storm track up through the
St. Lawrence temperatures will warm above freezing.
Dry conditions on Friday with temperatures near normal expected.
Model differences appear for the weekend with the GFS driving a
front through the region with a chance of showers. On the other hand
the Euro maintains some semblance of zonal flow with generally dry
conditions. Both models maintain near normal temperatures.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Gusty winds still an issue here with the 00Z TAF issuance,
particularly KALB and especially KPSF where a gust to 39 knots was
recorded at 651 pm. Winds will diminish this evening as the
pressure gradient relaxes.
Weak low pressure will scoot across the NY/PA border tonight,
bringing shower activity to KPOU. North of there, have allowed for
VCSH at KALB and KPSF. PSF is right on the edge between VCSH and
prevailing RA. For now have opted to keep it VCSH there. KGFL too
far north to be impacted by any activity.
Some MVFR restrictions are likely in any RA that develops.
Otherwise, look for VFR conditions.
Winds will pick up behind the system tomorrow although no where
near what they were today. Look for peak gusts to be up to 20
knots, especially in the favored channeling terminals of KALB and
KPSF.
Outlook...
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Low Operational Impact. Breezy NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of RA.
Thursday Night: High Operational Impact. Likely RA.
Friday: Moderate Operational Impact. Chance of RA.
&&
.FIRE WEATHER...
Conditions will remain brisk and chilly through early in the week.
The storm that brought the rain and snow to the area will continue
to slowly move away from the region. In the meantime, a weak
low pressure system over the Great Lakes region will move
southeastward to the coast bringing some light rainfall to areas
mainly south of Interstate 90 overnight. Higher pressure will
gradually build in from the west through mid week.
&&
.HYDROLOGY...
A public information statement was issued with the accumulated rainfall
totals from the past few days with amounts generally ranging from
1 to 3 inches.
Only some light rainfall is expected overnight for areas mainly
south of I-90 as a short wave passes just to our southwest.
Then mainly fair weather is then expected through mid week with
unsettled weather returning for the latter part of the week.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/OKeefe
SHORT TERM...IAA
LONG TERM...OKeefe
AVIATION...VTK/OKeefe
FIRE WEATHER...IAA
HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service Bismarck ND
944 PM CDT Sun Oct 23 2016
.UPDATE...
Issued at 943 PM CDT Sun Oct 23 2016
Little change for tonight other than to lower overnight lows a
couple of degrees per observed trends through 02 UTC.
UPDATE Issued at 635 PM CDT Sun Oct 23 2016
The forecast remains on track for the night and was blended to
observed trends through 23 UTC. Overall, the potential for patchy
fog remains unchanged, with the greatest chances west of the
Missouri River with upslope return flow.
&&
.SHORT TERM...(This evening through Monday)
Issued at 248 PM CDT Sun Oct 23 2016
Focus in the short term is on cloud cover and the potential for
fog tonight into Monday morning.
Model guidance has had a difficult time with cloud cover through
the day as in most places clouds stuck around a bit longer than
previous thought. Latest HRRR runs show clouds more or less
sticking around central and north through the night while other
models are more optimistic that central and north may clear out.
Went with a blend of models through the night but will have to
keep a close eye on it as cloud cover will play a role on if and
how much fog develops overnight and overnight lows in the James
River Valley.
As for fog the NAM has done a good job the past two nights of
showing where fog will develop. Tonight into Monday morning the
best chance appears to be north central and northwest with some
potential development across the central and west early Monday
morning. Low level moisture will be ample across the area, however
depending on when southeasterly winds pick up across the southwest
and cloud cover south central will play a large role in whether or
not fog develops.
.LONG TERM...(Monday night through Sunday)
Issued at 248 PM CDT Sun Oct 23 2016
Focus in the long term is on the chances for rain Tuesday into
Wednesday.
Model guidance continues to show two upper level troughs develop in
the mean ridge Tuesday and Wednesday. The best chance for rain
comes from the southern wave that develops over the central
plains. Wrap around precipitation will bring rain to the
southeastern part of North Dakota Tuesday afternoon into early
Wednesday morning.
The second wave develops further north in Canada and progresses
more slowly. Model guidance is in less agreement on the track of
this upper level wave. Latest solutions of the ECMWF show chances
for rain across much of North Dakota for most of Wednesday while
the latest GFS solution keeps precipitation north of the border.
Either way any rain would be light across northern North Dakota
and for now have went with chances for rain for north central and
northeast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 943 PM CDT Sun Oct 23 2016
Patchy fog is possible across much of western and central North
Dakota tonight into Monday morning, especially west of the
Missouri River including the terminal of KDIK. Otherwise, VFR
conditions are forecast for the 00 UTC TAF cycle. Southeasterly
winds with gusts of 20-25 kts are expected on Monday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...MM
LONG TERM...MM
AVIATION...AYD
Area Forecast Discussion
National Weather Service Denver/Boulder CO
903 PM MDT Sun Oct 23 2016
.UPDATE...
Issued at 900 PM MDT Sun Oct 23 2016
Tranquil weather conditions dominate the fcst region this evening
beneath an upper level ridge and light zonal flow aloft. As this
ridge slowly migrates eastward overnight should see winds aloft
turn southwesterly. High-level moisture upstream over Utah will
also gradually spread eastward over northwest Colorado overnight...
potentially reaching northwest corner of the forecast area...i.e.
Jackson...Grand and western Larimer counties by morning...if not a
few hours sooner than that. Do not expect to see any precipitation
with this advancing cloud cover. Otherwise it will continue dry
and mild elsewhere with the usual nocturnal drainage wind set up.
Made minimal adjustments to the forecast grids this evening.
&&
.SHORT TERM...(This evening through Monday)
Issued at 126 PM MDT Sun Oct 23 2016
Upper ridge remains over the area through Monday. Some high
clouds streaming over but mainly thin tonight, then thickening
from west to east on Monday. Expect the clouds to have a slight
effect on temperatures, combining with a little wind on the plains
to keep it mild tonight, and restraining highs a couple degrees on
Monday. With slightly warmer air off the ground, temperatures
should still get to near what we have this afternoon. With the
low/mid level air moistening a little from the west there could be
just enough instability for a few light showers over the mountains
in the late afternoon. More likely they will wait for evening.
.LONG TERM...(Monday night through Sunday)
Issued at 126 PM MDT Sun Oct 23 2016
There is southwesterly flow aloft Monday night, then a weak upper
trough moves across the CWA early Tuesday. West-northwesterly
flow aloft is progged from late Tuesday afternoon well into Wednesday
with an upper ridge to be over Colorado Wednesday night. The QG
Omega fields have weak upward energy for the CWA Monday night into
midday Tuesday, then weak downward motion is in place through
Wednesday night. The boundary layer winds are mostly normal
diurnal trends Monday night and Tuesday. There is northwesterly
downslope progged much of Tuesday night and southeasterlies
Wednesday. Moisture-wise, models seem to have a bit more with the
Monday night/Tuesday upper trough than the last model runs
indicated. The moisture is fairly deep in the mountains and there
is no low level moisture over the downsloping plains. By Tuesday
afternoon there is decent drying. Tuesday night through Wednesday
night look pretty dry. The Qpf fields had some measurable
precipitation Monday night and Tuesday, but it is mostly in the
mountains. Tuesday night through Wednesday night are dry. For pops
will go with 40-70%s in the mountains Monday night into mid day
Tuesday. There will be lesser pops for the foothills and maybe
10%s for the immediate plains. For temperatures, Tuesday`s highs
are 1.0-2.5 C colder than Monday`s. Wednesday`s highs are close
to Tuesday`s. For the later day`s, Thursday through Sunday, models
have the upper ridge in place for the CWA Thursday into Friday.
The ECMWF hints at a weak upper trough late Friday into Saturday,
the GFS does not. The GFs has a weak upper trough Saturday
afternoon and night, the ECMWF doe snot. Both have an upper ridge
on Sunday. Will keep things dry much of the time, with just a tad
of alpine pops Friday night and Saturday. Temperatures stay warm.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 900 PM MDT Sun Oct 23 2016
The usual nocturnal drainage wind pattern has setup across the
Denver metro area at this hour. Would expect little change in
this wind configuration for the remainder of the night. Speeds for
most of the Denver metro area should remain under 12 kts...although
the HRRR and RAP indicate a band of stronger southerly winds
across the southeast corner of the metro area between 05z -09z
tonight. Speeds in this area may be as much as 3-6 kts
greater...with speeds not expected to be more than 20 kts during
this 4-hour period. Overwise...should see a gradual increase in
cirrus overnight as high-level moisture continues to feed in from
the west and through the lee slope mountain wave.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Baker
SHORT TERM...Gimmestad
LONG TERM...RJK
AVIATION...Baker
Area Forecast Discussion
National Weather Service Caribou ME
1037 PM EDT Sun Oct 23 2016
.SYNOPSIS...
Strong low pressure will remain to our north overnight and
Monday. The low will weaken and move east Tuesday into Wednesday.
High pressure will cross the region Thursday.
&&
.NEAR TERM /THROUGH MONDAY/...
1030 PM Update: Cancelled the Wind Advisory as winds dropped off
considerably from this afternoon. West winds will gust to 25+ mph
overnight. The latest IR satl imagery showed clouds breaking up in
parts of central and downeast areas. Further n and w, clouds
holding on and should do so overnight. Temps have stayed up a bit
w/upper 30s for northern areas and low to mid 40s central and
downeast. Latest mesoscale guidance including the HRRR and RAP
show temps sliding back overnight w/clouds breaking up even across
northern areas.
Previous Discussion....
Some spotty rain and snow showers are possible across the far
north tonight. Otherwise, tonight will remain mostly cloudy over
central and northern areas with partial clearing Downeast.
Moisture wrapping around the low in Eastern Canada will back south
across the area on Monday keeping the region mostly cloudy, except
for partial sunshine along the coast. Some spotty rain showers,
and snow showers over the west, will continue. Winds will remain
gusty but are expected to be lighter than they have been today.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
An upper level trof remains across the region Monday night through
early Wednesday, then begins to move east later Wednesday, while
several disturbances move through the trof. A surface trof also
begins to move across northern areas Monday night, moves south
across the forecast area Tuesday, then exits Tuesday night. Expect
rain/snow showers across northern areas Monday night into
Wednesday. Based on diurnal temperatures, expect precipitation to
trend toward mostly snow showers from the evening through the early
morning hours then to rain showers through the morning into the
afternoon. Across higher terrain areas, expect precipitation to
remain mostly snow showers. Across Downeast areas, expect
rain/snow showers overnight with rain showers through most of the
morning and afternoon. Expect the most numerous rain/snow showers
across northern areas Monday night through Wednesday, with lesser
chances Downeast. An upper level disturbance and surface trof will
bring the most extensive snow showers across northern areas Monday
night into early Tuesday where light snow accumulations are
possible. Otherwise, with cold air aloft and moisture with the
upper trof expect mostly cloudy skies across the region.
Temperatures will be at below normal levels Tuesday/Wednesday.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Clouds finally decrease Wednesday night as the persistent upper level
low over the Canadian maritimes finally kicks off to the east.
With high pressure building in, clearing skies, and a cold
airmass, Wednesday night has the potential to be awfully chilly.
Went colder than most guidance for temperatures Wednesday night in
NW portions of the area including the North Woods, where the high
pressure will be building in first.
Mostly sunny and chilly Thursday, but the high pressure will be very
short-lived with increasing clouds late in the afternoon ahead of
the next system. Very good model agreement on the timing of the
next system for it still being several days out, with
precipitation moving in late Thursday night or Friday morning. It
may briefly start as a mix over Northern Maine, but not very
concerned about accumulations as warm advection should quickly
change everywhere over to all rain. Not a particularly juicy
system...probably a half inch or so of rain for most areas Friday,
with the rain perhaps lingering into Friday night and Saturday.
Friday night and Saturday is when model agreement goes from quite
good to poor. Quite a bit of uncertainty in when the precipitation
tapers off (does it end late Friday or linger into Saturday?).
Also, a good deal of uncertainty as to how cold it gets Sunday
behind the system.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
NEAR TERM: Generally MVFR conditions are expected across the
north tonight with VFR conditions downeast. Strong winds both
surface and aloft and deep mixing due to cold air advection will
result in strong gusty winds and potential turbulance across the
region tonight into Monday.
SHORT TERM: Generally expect MVFR conditions across the north and
mountains Monday night through Tuesday, with occasional MVFR
conditions possible Downeast. Occasional MVFR conditions are
possible across the entire region Tuesday night into Wednesday,
with the best chances across the north and mountains. Expect VFR
conditions Thursday. Conditions will then lower to IFR/LIFR
levels Thursday night, with MVFR/IFR conditions expected Friday.
&&
.MARINE...
NEAR TERM: The GLW fro the intra-coastal zones was downgraded to a
SCA through 8 am. The GLW for the outer waters remains in place
through 8 AM. SCA is likely on Monday. Strong winds and deep
mixing due to colder air over the relatively warmer waters has
resulted in very high seas, especially off the Washington County
coast where seas have topped 18 ft. Seas will remain high tonight
into Monday as the winds continue.
SHORT TERM: Small craft advisory conditions are expected Monday
night into Wednesday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory until 8 AM EDT Monday for ANZ052.
Gale Warning until 8 AM EDT Monday for ANZ050-051.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service Northern Indiana
1022 PM EDT Sun Oct 23 2016
.SYNOPSIS...
Issued at 725 PM EDT Sun Oct 23 2016
Breezy conditions diminish in the early overnight. Expecting a
quiet night with some clouds around especially by the lake and
lows in the 40`s. Monday will be dry with highs in the 50s and
approaching the low 60s.
&&
.UPDATE...
Issued at 1002 PM EDT Sun Oct 23 2016
Main question this evening is if any lake effect rain showers will
develop overnight and early Monday. Not much change in previous
shift`s expectations with latest guidance suggesting minimal lake
induced cape with equilibrium levels 6-7kft. One factor that is
looking more favorable is winds fcst to veer nnw creating a long
fetch, albeit for a fairly short period. Latest NAM/HRRR/ARW are
indicating some light qpf over Berrien County around daybreak
while RAP is dry. Given negatives discussed above and lack of
upstream development attm, maintained dry fcst.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 214 PM EDT Sun Oct 23 2016
Compact shortwave will move through the northern Great Lakes into
tonight. Rain was covering much of the U.P of Michigan with more
widely scattered showers into northern Lower Michigan. Further
south, effects of the wave will more limited, mainly in the form
of increased clouds overnight, breezy conditions this afternoon
and evening and maybe a chance for some light lake effect rain
showers after 6z as delta t`s drop to around 13 C with a NW fetch.
Several negatives for measurable precip with the lake effect
including low inversion heights, lack of deep moisture and limited
residence time given NW flow. Will maintain no more than 14 pops
for now and defer to eve shift to see if more materializes
upstream than current depicted by hi res models.
Otherwise forecast will become tranquil as cold front pushes
through the area, trimming about 10 degrees off of today highs for
expected afternoon temps on Monday.
&&
.LONG TERM...(Monday Night through Sunday)
Issued at 214 PM EDT Sun Oct 23 2016
Focus remains on approaching system to move out of the Dakotas
towards the region. Best chance for rainfall has been pushed back
somewhat with mainly NW areas seeing chances increase Weds
afternoon and then across the entire area Weds night. Have
expanded slight chance of thunder to all areas Weds night with at
least some instability to allow for an embedded storm or 2.
Trough lingers into Friday, but deeper moisture should be shunted
east with the main energy. This should result in a brief dry
period Thursday afternoon into Friday before another wave drops in
and brings chances of showers back. Temperatures will stay
seasonable in the wake of the mid week trough.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 725 PM EDT Sun Oct 23 2016
Core of the low level jet shifts east of the forecast area before
2am helping to allow for diminishing winds overnight. With that and
high pressure moving into the area, only real forecast issue for
this period will be the extent of cloud cover just around lake
near SBN especially overnight.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Small Craft Advisory until 4 PM EDT Monday for LMZ043-046.
&&
$$
UPDATE...JT
SYNOPSIS...Roller
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Roller
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AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1059 PM EDT Sun Oct 23 2016
.UPDATE...
Issued at 1058 PM EDT SUN OCT 23 2016
Did a quick update to make sure the near term forecast for
temperatures and dew points were on track with current
observations. These changes were published and sent to NDFD/web.
Also sent out a new zone forecast to update the time period
wording for tonight.
UPDATE Issued at 730 PM EDT SUN OCT 23 2016
Forecast seems to be in good shape so far this evening. Updated to
make sure the temp, dew point, and wind forecasts reflected the
ongoing conditions in the near term. Also ended up lowering wind
gusts overnight, as there has been a model high bias and the
ongoing forecast was unrealistic compared to current conditions.
All changes have been published and sent to NDFD/web. Changes were
minor enough that no new forecast package will be needed at this
time.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 430 PM EDT SUN OCT 23 2016
19z sfc analysis shows high pressure to the south starting to
yield to an inbound dry cold front to the northwest. This front`s
approach is responsible for the tightening pressure gradient
helping, along with good mixing under sunny conditions, to keep
the winds going from the southwest at 10 to 15 mph, or so, with
occasional gusts around 25 mph. These breezes, again along with
the full sunshine, support temperatures climbing into the upper
60s and low 70s. Dewpoints, meanwhile, are running in the upper
30s to lower 40s.
The models remain in good agreement aloft through the short term
portion of the forecast as they all show Kentucky in the midst of
fairly fast northwest flow between a deep trough to the northeast
and rather flat ridging west. A weak trough will pass by to the
north tonight into Monday morning but its energy stays well off to
the northeast to have any real affect on our weather. Given the
good agreement have favored a general blend with emphasis on the
higher resolution guidance from the HRRR and NAM12, along with
some deference to the COOP MOS guidance - especially Monday
night.
Sensible weather will feature a bit milder of a night as the winds
stay up better and the front limits the strength of the inversion.
Will allow for some river valley fog near dawn as we have had the
past couple of mornings. Another pleasant day is expected on
Monday with mostly sunny skies, breezy winds switching to the
northwest post fropa, and afternoon temperatures in the mid to
upper 60s. Drier and cooler air moves in Monday night with a
better potential for frost in the valleys early Tuesday morning.
Have added that to the grids along with a mention in the HWO.
Again used the CONSShort/ShortBlend as the starting point for the
bulk of the grids with adjustments to the night-time temps for
terrain as well as knocking dewpoints down in the afternoon a tad.
PoPs were zeroed out through the period - in line with all
guidance.
.LONG TERM...(Tuesday through Sunday)
Issued at 345 PM EDT SUN OCT 23 2016
The models are in good agreement through the work week then diverge
in their solutions. At the start of the period, heights will rise as
high pressure scoots into the area from the south. This high
pressure will be over the region Tuesday afternoon through Wednesday
morning, allowing lower dew points to mix down. This will lead to
the best chance of the period for some patchy frost Wednesday
morning. Winds shift to the southwest ahead of a shortwave trough
passage, allowing for warmer and moist air to infiltrate the region
Wednesday afternoon. A cold front is then expected to swing through
East Kentucky by Thursday evening with a chance for some showers
throughout the day. High pressure shifts into the area Thursday
night but quickly exits by Friday evening. Beyond Friday, the
forecast is a bit up in the air as model solutions diverge. So have
decided to remain close to the CR Superblend solution beyond Friday,
with minor changes made to the temperatures to account for night-
time inversions.
Temperatures will remain fairly seasonable through the period with
afternoon highs in the 60s and low 70s. Morning lows will start out
near freezing in the valleys on Wednesday morning, with all temps
moderating into the 40s/low 50s through the rest of the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 741 PM EDT SUN OCT 23 2016
VFR conditions are expected through the period. Winds have settled
down this evening to generally less than 10 knots. A few gusts
continue at KSYM and may continue for the next couple of hours.
Still expecting a dry cold front to cross through the region from
the NW through the overnight. This will keep many locations from
seeing light and variable winds overnight, despite clear
conditions. Winds will shift from SW this evening ahead of the
cold front to NW by tomorrow morning just after the frontal
passage. Some gusts above 10 knots may be possible during the
afternoon once more.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...JVM
AVIATION...JMW
Area Forecast Discussion...CORRECTED
National Weather Service North Platte NE
619 PM CDT Sun Oct 23 2016
.SYNOPSIS...
Issued at 306 PM CDT Sun Oct 23 2016
H5 hand analysis this morning had a continuation of the
broad ridging across the western and central portions of the CONUS.
Ridging aloft extended north into northern British Columbia and was
amplified by an upstream low off the coast of British Columbia.
The pattern across the western and central CONUS remains stagnant
this morning as little or no ht rises or falls were noted west of
the Mississippi river. Further east, a closed low was located over
southeastern Quebec with a trough of low pressure extending south
into New England. Ht. falls of 50 to 200 meters were from Maine
into the Canadian Maritimes. Further south, 50 to 100 meter rises
were noted over the Ohio Valley into the Carolinas. At the surface,
a cold front had passed through western and north central Nebraska
overnight and currently extended from southwestern Kansas into
northwestern Missouri. Skies were generally clear this afternoon
across the forecast area, with the exception of some mountain wave
cirrus across the southern third of the forecast area and some low
cloudiness trying to back into northeastern Nebraska from eastern
South Dakota. Afternoon temperatures as of 3 PM CDT ranged from 62
at Ainsworth to 67 at North Platte and Broken Bow.
&&
.UPDATE...
Issued at 554 PM CDT Sun Oct 23 2016
The ARW...NMM....HRRR and RAP models show some fog by morning
along highway 281. This would form near sunrise and lift mid to
late morning. The RAP model sounding seems conceivable so a new
forecast is in place for this feature.
&&
.SHORT TERM...(This evening through Monday)
Issued at 306 PM CDT Sun Oct 23 2016
Upper level ridging continues across the Rocky Mountain region as
high pressure slides slowly eastward across the upper Midwest.
Similar to the previous several days, quiet and dry conditions will
prevail. Clear skies tonight will allow temperatures to fall into
the mid to upper 30s across the forecast area.
On Monday, will continue to see dry weather, however, skies will
slowly become more cloudy throughout the day in advance of the
shortwave trough moving off the front ranges. This filtering in of
clouds from the west combined with cooler air filtering in on the
western side of the surface high will keep high temperatures across
the eastern forecast area a few degrees cooler than the last couple
days. Expect highs in the low to mid 60s across the eastern CWA.
Areas to the west across the eastern panhandle will still see highs
in the low 70s.
.LONG TERM...(Monday night through Sunday)
Issued at 306 PM CDT Sun Oct 23 2016
Monday night through Wednesday...In the mid range, the
main forecast challenges deal with the development of low clouds
and fog Monday night, along with the threat for precipitation
development Tuesday afternoon and Tuesday Night. For Monday night:
Thanks to increasing southeast winds, strong low level moisture
advection will commence across the forecast area, mainly east of the
Nebraska Panhandle. Dew points will increase into the middle and
upper 40s overnight which will lead to lows in the mid and upper 40s
Monday night-some 10 to 15 degrees above normal. Coverage of low
cloudiness will increase as well and as this cloudiness moves west,
fog will develop along the leading edge of the stratus. NAM12 BL RH
progs, as well as SREF fog probabilities indicate a high potential
for fog Monday night into Tuesday morning east of the panhandle and
west of a line from Valentine to Broken Bow. Ongoing forecast has
this mentioned right now and will be increasing coverage especially
over southwestern Nebraska based on the latest NAM12 and SREF visby
products which do indicate a high probability for fog development.
For Tuesday, fog and stratus will be slow to burn off from west to
east as a surface trough will track slowly from western into
central portions of the forecast area on Tuesday. The latest NAM12
is slightly faster with the track of the surface trough Tuesday
while the GFS20 is slower. This will limit any clearing along and
east of highway 83 Tuesday, leading to cooler temps in the eastern
forecast area given the expected cloud cover. Later in the
afternoon and evening, precipitation chances will increase in the
eastern forecast area, as a shortwave trough aloft, approaches the
surface trough. The models this morning are much weaker with the
capping inversion Tuesday afternoon/evening than yesterday`s runs,
which increases the confidence in thunderstorm development in the
east Tuesday night. Did make some changes to precipitation chances
in the east Tuesday afternoon/evening, mainly to draw pops further
west, however, they are still east of the highway 83 corridor.
Overnight, Tuesday night, the surface trough and upper level
disturbance will track slowly east-stalling across eastern
Nebraska. Boundary layer moisture will remain prevalent in the
northeastern forecast area, so low clouds are expected to persist
into Wednesday morning and possibly Wednesday afternoon in eastern
portions of the forecast area.
Wednesday Night through Sunday...Ridging will build back into the
central CONUS for Wednesday Night into Thursday Night. Temperatures
on Thursday may hit the lower 80s in far southwestern Nebraska as
H85 temps surge into the lower 20sC. This ridging will be short
lived however as a northern stream shortwave trough suppresses the
ridge-forcing a cold front into the forecast area later in the week.
There are some timing differences between the EC and GFS solutions
with their timing of this feature. The EC is 24 to 36 hours slower
with the front, so warm temperatures will carry over into Friday and
Saturday. Given the differences between the model solutions,
utilized the forecast blend for highs. As for lows, with a dry
airmass in place, blended lows were undercut 2 to 4 degrees to
better reflect the statistical guidance as well as climatology.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 619 PM CDT Sun Oct 23 2016
The ARW...NMM....HRRR and RAP models show some fog by morning
along highway 281. This would form near sunrise and lift mid to
late morning. Local IFR/LIFR is expected and confidence is
moderate for this event.
The models draw sfc moisture across ern SD/swn MN west by
morning forming the fog. VFR is expected all areas by 17z which
should continue Monday afternoon. Otherwise the upper level
disturbance across the Cntl Rockies moves east tonight...Monday
and spreads mid and high cloudiness across Western and North
Central Nebraska .
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SYNOPSIS...Buttler
SHORT TERM...Kulik
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Mount Holly NJ
933 PM EDT Sun Oct 23 2016
.SYNOPSIS...
A cold front will slide through our region early Monday morning.
High pressure centered over central Canada will build to our north
during mid week. A warm front, followed quickly by another cold
frontal passage is expected through our region late Thursday or
early Friday. High pressure follows to our south across the
Carolinas next Saturday with another cold frontal passage likely
Saturday night or Sunday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A potent mid-level short wave will continue to dive southeastward
from the Eastern Great Lakes overnight. Much of the forcing along
the path of the shortwave appears to be tied to warm air
advection on the nose of a strong 850 MB jet. This will tighten
the thermal gradient and where this sets up will be the placement
of a ribbon of frontogenetic forcing. Our northern zones look to
be on the southern end of the precipitation axis, however are
expected to see at least some showers as this system zips east-
southeast. As a result, we continued the idea of quickly
increasing POPs after Midnight but also tightened the gradient
southward. Looks like much of the measurable QPF is north of I-80
northward. Farther southward, just some increase in cloud cover is
anticipated overnight. Raised pops with the 9:30 pm update taking
into account the radar trends along with the latest RAP and HRRR
model runs which inched the shower activity slightly further
southward.
As a low-level jet arrives overnight along with accompanying warm
air advection, temperatures are not expected to drop off as much and
may even rise a bit toward morning. Lows were raised a couple of
degrees in spots with the last update to take this into account.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
A quick moving short wave and weak surface low will exit to our
northeast early in the morning. This feature will pull a cold front
offshore to start the day and will also amplify the trough aloft
across the region. As a result, any showers up north end very early.
As cold air advection increases during the day combined with
cyclonic flow and a tightening pressure gradient, there will be a
gusty wind once again. It looks like gusts should peak at around 30
mph especially from late morning on.
The increasing cold air advection combined with just enough moisture
should result in some stratocumulus lingering or developing. This
could be fairly extensive across the northern areas especially as
another strong short wave is forecast to arrive during the
afternoon. We therefore kept more clouds across the northern areas
through the day. Since the cold air advection is forecast to be more
notable in the afternoon, many areas should have temperatures get
into the 60s before the cooling starts. We used mostly a MOS blend
for the high temperatures.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
500 MB: A cold trough in the northeast USA will weaken to the
Maritimes late Wednesday as a short wave moves through the Great
Lakes- Ohio Valley region. That short wave crosses the mid Atlantic
coast Friday with a broader trough to move east across our area
Sunday.
Temperatures: October through the 22nd has averaged around 4 degrees
above normal. The chill during midweek will make a significant dent
in that above normal departure but still leave the month as a
whole, averaging around 2 degrees above normal. Calendar day
averages Tuesday should be around 3 TO 4 degrees below normal, 5
and 10 degrees below normal Wednesday and Thursday, thereafter
within 3 degrees of normal Friday through Sunday.
Forecast basis: Unless otherwise noted, a 50 50 blend of the 12z/23
GFS/NAM MOS guidance Monday night-Tuesday night, thereafter the
12z/23 GFS MEXMOS Wednesday and then the 15z/23 WPC guidance
Wednesday night -Sunday, at times blended with the 12z/23 GFS MEXMOS
guidance.
The dailies...
Monday night...Clear to partly cloudy except there could be a sprinkle
or flurry in the Poconos toward dawn Tuesday. Seasonable. a gusty
northwest wind to 20 mph high terrain and I-95 region to the coasts.
Confidence: above average except below average any pcpn.
Tuesday...scattered sprinkles/flurries possible during the morning,
mainly Poconos, otherwise...considerable diurnal driven cloud
cover, breezy and cool. Northwest wind gusts to 25 mph or 30 mph.
Confidence: above average except below average any pcpn.
Tuesday night...Freeze and or frost is an above average
likelihood for e PA and NJ countryside (probably excluding
Philadelphia center city) and adjacent sections of ne MD and N DE
as northwest winds diminish. -4C at 850. Confidence: above
average. The 12z/23 nam boundary layer winds tend to show a little
bit of stirring (transfer) most of the night east of I-95. That
may indicate a cool bias in the NAM temps near the shore. On the
other hand, SREF modeled PWAT which is near .3" inches early
Tuesday morning, lowers to less than .25" from ACY- PHL northward,
indicating the columns cold and dryness. This very low pwat tends
to be a prerequisite for below normal night time cold. Continues
to be highlighted in the HWO. Hourly temps sampling <36 for areas
of frost and <33 for widespread frost. Since there may be a slight
stirring of the wind, the frost might be spottier than anticipated
but the freezing temp fcst looks pretty solid along and north of
I-78.
Wednesday...Quite cool with highs 5 to 10 degrees below normal
despite partly to mostly sunny skies. Northwest to north winds.
Confidence: above average.
Wednesday night...There will be another risk for freeze and or frost
on Wednesday night. However, unlike Tuesday night, increasing
high clouds after midnight may somewhat limit radiational
cooling. If the clouds come in early enough, this could inhibit
frost development. For now, continue a mention of patchy frost for
areas with a forecast min of 35 degrees or less, since temps will
plummet during the evening,despite bands of thin cirrus. Thicker
cirrus should not arrive until after 2am when the damage may
already be done. Confidence: average
Thursday and Thursday night...Low pressure and its waa pattern
will run into marginally cold airmass over ne Pa and nw NJ where
a a little snow, sleet or freezing rain is possible during the
morning, conditional on spotty precipitation arriving prior to 11
am. Will add the potential for a few slippery spots in the HWO
that area. Used the partial thickness tool for ptype, manually adding
snow. there is quite a bit of model discrepancy regarding whether
the column will still be cold enough for snow to reach the ground
but it is possible. No accums expected, other than a trace of sleet
and/or snow in the hills and mountains.
Small chance of an isolated thunderstorm during the evening on the
Delmarva but not mentioned in the grids.
Otherwise, max temps may not occur until sometime late in the day
or evening. Am suspicious that the fcst max temps issued at 330 PM
along and north of I-78 are 3F too warm.
Please see WPC for qpf amounts (around half an inch give or take a
quarter inch). I count this as somewhat beneficial rain for our
area.
Confidence: Average except below average on any mixed ptype vcnty
I-80 north.
Friday...Partly sunny and seasonable. northwest wind gusts 15 to
20 mph. Confidence: average.
Saturday and Sunday...Fair and seasonable. A cold frontal passage
is probable but with model timing differences. Confidence: below
average, especially Sunday.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Tonight...VFR with an increase in clouds, especially north of KPHL.
Lower VFR ceilings should be confined from about KABE to KTTN on
northward. The main shower activity after 04z should stay north of
KABE and KTTN. West to southwest winds diminishing to 10 knots or
less, although some increase may occur toward daybreak Monday with a
wind shift to the northwest.
Monday...VFR ceilings around at or above 5000 feet. Northwesterly
winds 10-15 knots with gusts up to 25 knots.
Outlook...
Monday night through Wednesday night...mostly VFR conditions expected.
Gusty northwest winds to 25 kt expected Tuesday afternoon.
Confidence: above average.
Thursday...VFR ceilings Thursday should lower to MVFR conds in periods
of rain (with possible localized IFR) Thursday night. East wind becoming
southeast. Confidence: above average.
Friday...VFR. northwest wind gust to 15 or 20 kt. Confidence: average.
&&
.MARINE...
Intense low pressure will continue to move well north of New England
through tonight, while an upper-level disturbance arrives from the
northwest toward morning. This will allow the winds to decrease
through this evening from south to north, however a low-level jet is
forecast to arrive toward morning before shifting offshore during
Monday morning. The strongest low-level flow is forecast to occur
during warm air advection, therefore it is questionable how much
mixing can occur down to the surface. Cold air advection then
increases during Monday especially in the afternoon. The combination
of both of these is expected to contribute to advisory level gusts
through Monday. Eventhough we have a lull here in the late evening
with the winds, they are expected to increase again toward
sunrise. Will maintain SCA headline through the overnight.
Since the stronger winds aloft are forecast to move through during
a less favorable mixing signature, gusts were kept below gale
force. While there should be a lull for awhile this evening,
especially on Delaware Bay, it should be short enough and
therefore a Small Craft Advisory is in effect for all zones
through Monday.
Outlook...
Monday night and Tuesday...SCA conditions are expected to continue
intermittently as northwest winds occasionally gust above 25 kt
(though seas may drop off below 5 ft. SCA headline as of the 330
PM forecast was extended through Monday evening with future
shifts to rereview for extensions. Confidence: above average.
Wednesday and Thursday...No marine headlines anticipated. Northwest
to north winds gusting to 15 kt Wednesday becoming east to southeast
Thursday. Confidence: average.
Thursday night...Southeast to south winds could increase above SCA
criteria on the Atlantic coastal waters late. Confidence: average
Friday...No marine headlines anticipated at this time. Northwest
wind gusts to 15 or 20 kt. Confidence: average
&&
.CLIMATE...
Our forecast indicates October should average at least 2 degrees
above normal for PHl and ABE. Some of the recent forecasts have
been colder and that may mean PHL and ABE slip to around 20th
warmest October on record, which is only noteworthy in that the
excessive monthly warmth of July, August, September eased in
October. Will reevaluate tomorrow and Tuesday.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until midnight EDT Monday night for
ANZ430-431-450>455.
&&
$$
Synopsis...Drag
Near Term...Gaines/Gorse
Short Term...Gorse
Long Term...Drag
Aviation...Drag/Gorse
Marine...Drag/Gaines/Gorse
Climate...
Area Forecast Discussion
National Weather Service Phoenix AZ
820 PM MST SUN OCT 23 2016
.SYNOPSIS...
A low pressure system will move towards the Pacific Northwest early
this week. This storm system will draw a considerable amount of
subtropical moisture into the Desert Southwest with the threat of
isolated showers and thunderstorms starting this evening and
continuing through Monday night. The best chance of showers will
occur Monday over south central Arizona, with afternoon thunderstorms
possible. Drier and warmer conditions will return by the middle of
the week.
&&
.DISCUSSION...
Jetstream winds from the southwest had increased over the region in
response to a strengthening Pacific low pressure system off the west
coast which is edging eastward. Also noticeable in regional weather
balloon soundings was an increase in moisture from the south,
stretching from San Diego to Tucson. Isolated afternoon thunder-
storms had developed over portions of southern CA related to an
embedded shortwave, while thunderstorms in the vicinity of Tucson
were related to afternoon instability under an increasing difluent
flow aloft. In other words moisture, instability, and strong
jetstream winds were slowly increasing this evening, setting up a
better chance for showers and afternoon thunderstorms Monday
afternoon and evening as a number of Pacific shortwaves move into
the region. Current forecast show this trend through Monday night,
therefore no short term updates needed.
.PREVIOUS DISCUSSION...218 PM MST...
Latest streamline analysis shows a broad ridge encompassing the
southern states while a low pressure system in the eastern Pacific
approaches the Pacific Northwest. Southwesterly flow between these
two systems is transporting warm and moist air from the subtropics
into the region. In the lower levels, dewpoints have jumped abruptly into
the mid 60s across the Yuma in response to the low-level southerly
flow. Further east across southeastern Arizona, latest satellite
imagery shows that isolated convection has initiated, mainly across
the higher terrain.
Steering flow is generally 10 kt or less associated with the 700 mb
anticyclone centered near Nogales and the existing activity is not
expected to move towards central Arizona. However, some CAMs suggest
isolated cells will drift into portions of Pima and Pinal Counties
late this afternoon, though latest runs of the HRRR continue to
indicate little potential for convection this far north. PoPs were
again lowered slightly from Phoenix northward, but raised across
southwestern Maricopa County, albeit to only around 20 percent. Hi-
res guidance remains in good agreement that any activity that
develops will likely dissipate this evening.
Deeper moisture will continue to stream northeastward ahead of an
approaching southern-stream short-wave trough Monday. NAEFS IVT
appears to be strongest across southern CA and western AZ during the
late morning and early afternoon with a widespread area exceeding the
95th percentile. Nearly all CAMs are suggesting a large shield of
clouds/light rain and sprinkles will encompass the area during the
afternoon. Global models are also indicating that areas that see
less clouds will destabilize, supporting 100-300 J/kg of SBCAPE.
Conceptually, the best chance for precipitation will actually be
during the evening across central Arizona, when forcing for ascent is
maximized ahead of the vort max. Although organized thunderstorms are
not expected, SPC probabilities indicate at least a slight chance of
thunder across much of the area into the evening.
.PREVIOUS DISCUSSION...
A gradual clearing and drying trend from the west is expected Monday
night into Tuesday as the last short wave moves through central
Arizona and then quickly exits east into New Mexico, followed by
building high pressure and increasing subsidence. By Tuesday morning
there should be just a lingering slight chance of showers over the
higher terrain east of Phoenix with mostly sunny skies developing
over the central and western deserts. High temps will climb slightly
Tuesday and into the low 90s from Phoenix westward due to increasing
sunshine and mixing.
For Wednesday into Thursday, strong high pressure aloft is forecast
to build back into the desert southwest, as another large area of
low pressure sets up just off the west coast and pumps up the ridge
downstream and over our area. High temps will climb back into the
middle 90s, with a high of 95 forecast in Phoenix by Thursday; that
would be over 10 degrees above seasonal normals. It should stay dry
for the most part, though a minor short wave lifting out of the deep
trof will brush by far southeast California Thursday leading to a
slight chance of a shower over the higher terrain of Joshua Tree NP.
Latest ECMWF and GFS have come into much better agreement for the
latter portion of the extended forecast, and the GEFS members also
have come into better alignment; we expect that in general the ridge
will remain rather strong over the desert southwest but there will
be continued short waves moving out of the trof along the west
coast, riding across and over the top of the ridge and bringing in
some modest moisture and UVV, enough to warrant a slight chance of
showers over the western deserts - mainly over higher terrain areas
of southeast CA. The central Arizona deserts should remain dry and
warm through the period however. Latest NAEFS POPs trends also
support the relatively dry conditions during the Friday through
Saturday period.
&&
.AVIATION...South-Central Arizona including KPHX, KIWA, and KSDL:
Southeast California/Southwest Arizona including KIPL and KBLH:
A Pacific weather system is expected to result in increasing mid and
high clouds tonight and Monday, leading to a chance of showers and
thunderstorms Monday afternoon and evening. Through 15z Monday,
light south to southeast winds 5 to 8 knots. Increasing clouds,
becoming bkn aoa 14 thsd agl after 10z Mon. From 15z Monday to 02z
Monday. South to southwest winds 7 to 12 knots. Sct-bkn clds aoa 8
thsd agl, a chance of showers and afternoon thunderstorms.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
High pressure redeveloping over the Desert Southwest will bring dry
conditions and well-above normal temperatures to the region on
Wednesday and Thursday. Another weather system brushes the Desert
Southwest late Thursday through Friday for an increase in humidities
and a slight chance of showers -mainly for southeast California and
southwest AZ. Warmer and drier weather is expected to return for
next Sunday. No strong winds are anticipated through the forecast
period. Minimum humidities stay at or above 20% on the lower desertsevening
for the most part and overnight recovery remains at least good.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Vasquez/Hirsch
PREVIOUS DISCUSSION...CB
AVIATION...Percha FIRE WEATHER...Percha
Area Forecast Discussion...UPDATED
National Weather Service Shreveport LA
940 PM CDT Sun Oct 23 2016
.DISCUSSION...
A band of showers is moving eastward near the Interstate 35
corridor south of the DFW Metroplex. The latest NAM did not even
initialize with this activity, but the HRRR does show it. Radar
trends over the last couple of hours indicate this band of
precipitation is weakening. The 00z KSHV sounding shows that the
column is extremely dry. Current thinking is these showers will
continue to weaken and dissipate as they encounter an increasingly
dry airmass to the east, and this trend is supported by the HRRR,
which dissipates the rain by 08z.
Otherwise, extensive cirrus clouds blanket the entire area. Sky
grids were updated to reflect this. A few other minor edits were
made to the hourly temp, dewpoint, and wind grids based on latest
trends. The overnight low temperature forecast was left intact.
Updated products will be sent shortly. /09/
&&
.PREV DISCUSSION... /issued 626 PM CDT Sun Oct 23 2016/
AVIATION...
VFR conditions should continue through the 24/00Z TAF period.
Extensive areas of cirrus cigs will continue across the region for
the next 24 hours...near and ahead of a shortwave over W TX this
evening that will gradually shift E into Ncntrl TX overnight and
into the area Monday. These elevated cigs should inhibit patchy FG
development overnight...but could see some stratocu development
occur over Scntrl and Ecntrl TX after 09Z...which may affect the E
TX terminals by daybreak. Still not confident enough that MVFR
cigs will develop over this area after 12Z...so have omitted
mention attm. However...a sct cu field should develop over E
TX/extreme SW AR/possibly Wrn LA by midday...with the elevated
cigs possibly lowering a bit further to around 15kft especially as
the shortwave enters E TX after 12Z. Light S or Lt/Vrb winds will
continue through the TAF period. /15/
PREV DISCUSSION... /issued 219 PM CDT Sun Oct 23 2016/
DISCUSSION...
High pressure ridge over northern gulf will dominate wx pattern
next few days, with above normal temps in the daytime. Although
dewpoints will begin to rise in lgt southerly flow and cirrus
clouds will occur intermittently, remainder of atmosphere will
remain quite dry. Cirrus will affect overnight lows which will be
svrl degrees warmer than those of last night. Daytime highs could
be slightly tricky Monday as these high clouds will begin to push
se of area by late in the day, where portions of area that clouds
leave could achieve a couple extra degrees. Short wave passing
north of area may squeeze out isold shower mainly north of I-30,
as moisture further south simply insufficient for any convection.
Upper ridge to remain established into next wknd with continued
dry and fairly persistent temps thru that time frame. /VII/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 55 80 56 82 / 0 0 0 0
MLU 51 80 54 83 / 0 0 0 0
DEQ 52 80 55 80 / 0 0 0 0
TXK 55 80 56 80 / 0 0 0 0
ELD 51 78 53 81 / 0 0 0 0
TYR 60 82 58 82 / 0 0 0 0
GGG 57 80 56 82 / 0 0 0 0
LFK 56 82 56 83 / 0 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
09/15
Area Forecast Discussion
National Weather Service Las Vegas NV
826 PM PDT SUN OCT 23 2016
.SYNOPSIS...A Pacific storm system will impact the region tonight
through Monday. This will bring increased cloudiness as well as
chances for rain and isolated thunderstorms. More tranquil weather
is expected during the middle of next week before another series of
storms takes aim at the region late in the week through next weekend.
&&
.UPDATE...Showers are moving through portions for the Mojave Desert
this evening including the Las Vegas Valley and portions of San
Bernardino and Southern Inyo Counties. Isolated thunderstorms have
occurred in the vicinity of Daggett. Gusty winds to 35 mph have
been observed with these showers. Red Flag Warning has been allowed
to expire as moisture has increased across the warned area. Areas
of shower activity will continue well into Monday. This trend is
currently reflected in the forecast so no changed have been made.
.SHORT TERM...Through Wednesday Night
As for our current products. Based on latest observations and
guidance having a hard time justifying the Wind Advisory so am going
to cancel that product with the afternoon issuance. It does look
breezy to locally windy this afternoon and Monday in parts of Nye,
Esmeralda and Lincoln Counties but not widespread enough for
headlines.
So far more bark than bite in regards to rainfall. Lots of mid/high
level moisture streaming into the Mojave Desert/Southern Great Basin
but little in the way of dynamics or instability to help generate
any more than virga or probably just a light rain shower at the
higher elevations.
As the air mass continues to undergo moistening from the mid-levels
down to the surface tonight stronger dynamics should start to come
into play as jet noses into Southern California placing much of the
Mojave Desert and southern Nevada under the left front exit region.
Some discrepancy between the operational models and HRRR on exactly
where north/south lines of showers/embedded thunderstorms develop.
The operational models remain consistent developing a line between
the Morongo Valley-Spring Mountains-Caliente. Meanwhile, the HRRR is
further west between Ridgecrest-Beatty-Ely. In the end, both
solutions may turn out correct so did not much change to inherited
POP grids which paint the highest POPs in a corridor between Las
Vegas and Beatty tonight/Monday morning. By Monday afternoon the
lines should start dissipating with showers/thunderstorms becoming
more scattered in coverage under slightly more unstable air mass.
Any residual showers/thunderstorms will come to an end Monday night
as dry/more stable air mass develops under building ridge of high
pressure. High pressure stays in control of our weather regime
Tuesday and Wednesday.
.LONG TERM...Thursday through Sunday.
Southwest flow over the area with high pressure to the east and
troughing to the west on Thursday with extended models in agreement.
However, as with previous model runs differences really start to
show up Friday through the weekend. The ECMWF continues to be the
much faster and more progressive model compared to the slower GFS
and Canadian runs. By Thursday afternoon the ECMWF already has
precipitation reaching the southern Sierra while the other models
don`t bring in it until Friday morning. The one thing that the
models basically agree on is the placement of the main rain band
which stretches from far western San Bernardino County up through
Inyo and eventually across Lincoln County while leaving Clark,
eastern San Bernardino, and Mohave Counties generally dry except for
some light scattered showers. Went ahead and kept the current
rainfall timing alone in the grids due to the continued uncertainty,
but upped the pops for Inyo and Nye Counties with likely in the
higher terrain of Inyo. The southwest flow into the Sierra should
help limit how much rain shadowing occurs with a good possibility of
a decent rain event for Inyo County. Although the timing is off on
the models it looks like much of the precipitation will be out of
the area by Saturday as high pressure quickly reestablishes itself
over the area. This would bring a quicker warming trend back to the
area Saturday and Sunday. Even on Friday with the thicker clouds,
most areas will continue to see slightly above normal temperatures.
&&
.AVIATION...For McCarran...Light winds are expected through the
evening. However, with some of the showers and potential
thunderstorms that will move toward the area its possible that some
stronger winds associated with these storms will move into the
valley. The best window for this happening will be between 02z-08z.
Showers will also be possible in the valley, but thunderstorms look
to remain west and northwest. Cigs down to 8-10K feet overnight.
Scattered showers possible through midday Monday with cigs around
10k feet and south winds increasing to around 10-20kts in the
afternoon.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Scattered showers and thunderstorms expected overnight
and Monday with a drying trend from west to east Monday afternoon.
Cigs around 8-10k feet over most areas. Gusty winds will continue
this evening for Inyo, Esmeralda, and central Nye Counties with
south winds over most areas Monday 10-20kts.
&&
.FIRE WEATHER...Expanded the Red Flag Warning to include Fire Zone
460 as local red flag conditions are being met. Winds will diminish
tonight only to increase again Monday. Humidity levels will be
higher on Monday so there is not threat of Red Flag conditions being
met. Drier and more stable weather is in the forecast Tuesday
through Thursday with unsettled weather returning late in the week
and next weekend.
&&
.SPOTTER INFORMATION STATEMENT...Chances for rain and perhaps
isolated storms will increase on Sunday and Monday. Spotters should
report significant weather according to standard operating
procedures.
&&
$$
Short Term/Fire Weather...Pierce
Long Term/Aviation...Gorelow
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter
Area Forecast Discussion
National Weather Service Bismarck ND
335 AM CDT Mon Oct 24 2016
.SHORT TERM...(Today and tonight)
Issued at 334 AM CDT Mon Oct 24 2016
Focus in the short term is fog and low stratus cloud formation this
morning. Attention then turns to the potential strength of the
southeast winds.
Currently...surface high pressure was over the Red River Valley,
centered over the border of ND/MN. Temperatures had dropped into the
mid 20s/lower 30s there with light winds, and fog had begun to form
over parts of the eastern third of ND, including the Devils Lake
Basin and James Valley. The latest iterations of the short term high
res HRRR model seems to have a good handle on the current area of fog
formation, suggesting that the area along and east of the Coteau is
most at risk for dense fog. This model also suggests the fog will
linger into the later morning hours. After collaborating with Grand
Forks and Aberdeen NWS offices, and noting that web cams not yet
indicating any widespread fog, decided that we will mention patchy
fog north central, and patchy dense fog from the James Valley to the
Devils Lake Basin counties. Should dense fog develop, we can issue a
short term Special Weather Statement to address more widespread low
visibilities.
Meanwhile, at upper levels a strong ridge was established over the
Rockies. This upper level ridge axis is forecast to move east into
the Dakotas tonight. Broad surface low pressure over the Rockies,
and high pressure moving east today will allow southeast winds to
develop. A strong low level h925/h850 jet is forecast to develop
from the southern Plains northward into Saskatchewan by this
afternoon. Expecting southeast winds to be a bit stronger than the
model blends, and raised wind speeds to 15 to 20 mph with gusts to
25 mph - beginning late this morning and continuing through the
afternoon. Bufkit soundings indicate that the low level jet remains
strong tonight and possibly continues to mix out at the surface at
times, but noted that a low level inversion develops and may keep
the higher winds aloft from mixing. Confidence is not high enough to
keep those higher wind speeds mentioned tonight.
.LONG TERM...(Tuesday through Sunday)
Issued at 334 AM CDT Mon Oct 24 2016
Focus in the long term is on the chances for rain Tuesday into
Wednesday.
The upper level ridge over the Dakotas Monday night begins to
flatten out as it moves east. Southwest flow aloft becomes
established over the Rockies with a large-scale upper level low off
the west coast. A shortwave emerging from the 4-corners area moves
northeast through the flow Monday night and reaches the Dakotas
Tuesday morning. This wave will bring an increase of mid level
moisture, and lifting associated with the established low level jet
will result in rain showers over central and eastern ND. At this
time it appears that the James Valley and into eastern ND are poised
to receive the bulk of the rainfall...with the possibility of
anywhere from 0.10 to 0.50 inches of rain.
Another shortwave emerging from the west coast system emerges from
the Pacific Northwest on Tuesday and reaches southern Saskatchewan
Tuesday night/Wednesday morning. Today`s model runs suggest that
showers from this wave will remain north of the Canadian border on
Wednesday.
The western ridge builds back over the Rockies Thursday, with yet
another series of shortwave breaking down the ridge. Models are not
in good agreement regarding the timing and track of these
shortwaves. Model consensus suggests keeping any mention of
precipitation out of the forecast for the end of this week, with
only slight chance mentions on Saturday.
Continued mild with highs in the 50s and 60s this week. A cooler
weekend ahead with highs in the 40s and 50s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1242 AM CDT Mon Oct 24 2016
Corrected discussion.
Patchy fog is possible across much of western and central North
Dakota this morning, but especially from the Turtle Mountains
through the James Valley, affecting the KJMS terminal. Otherwise,
VFR conditions are forecast for the 06 UTC TAF cycle.
Southeasterly winds with gusts of 20-25 kts are expected late this
morning and afternoon.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...JV
AVIATION...JV
Area Forecast Discussion
National Weather Service Flagstaff AZ
930 PM MST Sun Oct 23 2016
.SYNOPSIS...A trough of low pressure will move across
Arizona through Tuesday morning with chances for showers and
thunderstorms. Drier and warmer air will move over the state
Tuesday. Above average temperatures are expected this week. Another
trough will brush Arizona late in the week into next weekend.
&&
.DISCUSSION...A trough of low pressure is moving onto the west coast
this evening. Thunderstorms have developed around and southwest of
Las Vegas this evening. The HRRR did resolve this activity...and
moves it northeast through Monday morning (not eastward into
Arizona). The HRRR also depicts convective lines breaking out over
northern Arizona after 20Z Monday. Will update forecast to back off
on pops over western and northern Coconino County late tonight and
early Monday morning.
&&
.PREV DISCUSSION /151 PM MST/...For tonight, model forecasts continue
to forecast a plume of low level moisture originating from the Gulf
of California to slide northward across Mohave, and western Yavapai
and Coconino counties. With that said, most high resolution guidance
shows only isolated storms associated with this moisture push. As a
result, mainly low chances for showers and thunderstorms are
forecast west of line from Payson to Flagstaff to Page.
On Monday, better moisture arrives from west to east as the Gulf
of California plume combines with a secondary push of moisture
originating from the east Pacific. This moisture will combine with
forcing from a passing shortwave trough to cause increasing
chances for storms across all of northern Arizona. On Tuesday,
chances for storms decrease as the atmosphere stabilizes on the
backside of the trough.
On Wednesday and Thursday, heights quickly rebound as an upper-
level ridge builds across northern Arizona. This will cause a
period of dry weather and increasing daytime temperatures. From
Friday onward, model uncertainty becomes quite high. A few
deterministic and ensemble model forecasts predict that a
shortwave trough may clip the region causing some convective
activity around Friday/Saturday. At this point, the forecast calls
for only slight chances for storms during this time.
&&
.AVIATION...For the 06Z forecast...VFR conditions are expected to
continue through 12z then deteriorate afterwards. Isolated showers
will be possible west of a line from Page to Payson. After
12z...Lowering ceilings and increasing showers will develop and
spread from west to east across northern Arizona on Monday. Isolated
thunderstorms are expected. Look for MVFR/IFR conditions with
stronger showers and thunderstorms. Aviation discussion not updated
for TAF amendments.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS/RR
AVIATION...McCollum
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Goodland KS
242 AM MDT Mon Oct 24 2016
.SHORT TERM...(Today through Wednesday Night)
Issued at 241 AM MDT Mon Oct 24 2016
Early morning WV imagery and RAP analysis shows large scale
ridging continuing to dominate the pattern across the central
US. At the surface as front is stalled along the front range, with
high pressure centered over the northern Mississippi River Valley
extending south and west towards our CWA.
H5 ridge flattens as a shortwave trough (currently over the Pacific
NW) propagates eastward through the Northern Plains then through
central KS Tuesday-Tuesday night. Ridging then rebuilds over the
Central Rockies and Plains Wednesday. While temps are slight cooler
today (upper 60s/lower 70s) they are still above normal (by about
10F)...and temps will only trend upwards over the next few days.
This pattern will tend to keep very dry conditions in place through
these periods.
Return flow ahead of this upper level shortwave trough and
associated (weak) cold front is still advertised tonight and
Tuesday morning, and should bring bountiful BL moisture to our
CWA. SREF/NAM/ARW/NMM all show fog/stratus developing and there is
potential for dense fog to develop as moisture pools along the
prefrontal surface trough. Drier BL air may begin to move eastward
due to shift in flow to the southwest behind surface trough, which
could help erode the western extent of the fog/stratus or help
clearing from the west to the east. For now I kept fog mention in
place with no major changes midnight tonight through Tuesday
morning.
Regarding shower/thunderstorm chances Tuesday: The upper
level shortwave trough and H3 jet streak that move through our
region Tuesday will lead to good forcing in our east. Air mass below
600mb remains dry, and main CAPE axis will remain ahead of of
surface trough. This surface trough would also act as main focus for
initation Tuesday afternoon/evening and guidance continues to trend
eastward. Due to limited instability in our east and the very dry
low levels confidence is low in any measurable showers or
thunderstorms. Guidance still has a very small area in our
southeast, but considering trends I wouldn`t be surprised if even
this is pulled east with next run of models.
.LONG TERM...(Thursday through Sunday)
Issued at 241 AM MDT Mon Oct 24 2016
H5 ridge dominates the long term pattern with above normal
temperatures and generally dry weather. Northwest flow aloft on
Thursday will become westerly as the ridge axis pushes eastward
out of the central Rockies and into the central Plains on
Friday. A deep trough will traverse the northern Plains and the
southern Canadian Plains Friday afternoon and turn the upper flow
northwestward once more. No precipitation is expected as the
associated weak cold front and trough traverse the region. The
ridge amplitude increases as we head into Saturday and Sunday with
dry conditions continuing into the beginning of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1119 PM MDT Sun Oct 23 2016
VFR expected at both KGLD and KMCK through the TAF period. Light
winds tonight will gradually veer to the southeast by Monday
morning and increase to around 10kts through the day around a
large area of high pressure centered near the Great Lakes.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...024
Area Forecast Discussion
National Weather Service North Platte NE
343 AM CDT Mon Oct 24 2016
.SHORT TERM...(Today)
Issued at 321 AM CDT Mon Oct 24 2016
Surface high pressure over the northern into central plains early
this morning. Scattered cirrus moving east across western Nebraska.
Removed patchy fog from north central zones after sunrise with dew
point spreads 3F to 4F over the surrounding area. High pressure
will be recirculating cooler air from the east northeast through
the day with highs in the lower 60s north central to the low 70s
over the panhandle and southwest Nebraska. Winds will shift to the
southeast over the west late this afternoon.
.LONG TERM...(Tonight through Sunday) Issued at 321 AM CDT Mon
Oct 24 2016
Appears to be a decent set up for patchy fog late tonight into
Tuesday morning as gulf moisture increases on southerly low level
flow. Also expecting stratus to develop/spread northward into the
region after midnight tonight. This may be slow to burn off across
southwest into central Nebraska Tuesday morning. Mild tonight with
southerly flow and increasing moisture (lows in the 40s). A
shortwave and associated Pacific cold front will cross the area
Tuesday afternoon and Tuesday night. Limited instability and the
increase in moisture could yield a few showers or weak
thunderstorms across eastern portions of north central Nebraska
Tuesday afternoon and evening, but the better chances look to be
across eastern Nebraska.
Upper level ridging will then dominate the weather for the end of
the week into the weekend. Another weak disturbance and Pacific
cold front will cross the area Friday. Little moisture available
for this system to work with, and a dry frontal passage is
expected. Ahead of the system Thursday, a plume of very warm air
aloft will spread east, and highs could reach 80 degrees or better
across western Nebraska. Friday will be a few degrees cooler, but
still expecting 70s. Some weak cold air advection Friday night
will cool temperatures a little further for Saturday, but still
above normal for this time of year, with highs ranging from 60
degrees in O`Neill to 70 degrees in Ogallala. Warmer again Sunday
as more warm air spreads into the area from the southwest.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1122 PM CDT Sun Oct 23 2016
The ARW...NMM....HRRR and RAP models continue to show patchy fog
by morning along and east of highway 281. This would form near
sunrise and lift mid to late morning. Local IFR/LIFR is expected
with the fog and confidence is moderate for this event.
Otherwise VFR is expected all areas from 17z onward through 06z
Monday evening. Mid and high cloudiness will spread through
Western and North Central Nebraska. These clouds are associated
with an upper level disturbance moving through the Central
Rockies.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Power
LONG TERM...Taylor
AVIATION...CDC
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
343 AM EDT Mon Oct 24 2016
.SYNOPSIS...
A cold front will cross the central Mid-Atlantic this morning.
High pressure will return to the region through midweek. Low
pressure will cross to the north late in the week with the cold
front crossing the area Thursday into Thursday night. High
pressure returns for Friday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A cold front currently stretches across Pennsylvania and down the
Ohio Valley. Clouds and showers can be found behind the front, where
better vorticity resides. However, there is a southwesterly low
level jet ahead of the front containing winds of 50-55 kt. RAP
soundings suggest the jet drops as low as 1500-2000 ft. Since
midnight there have been a few 40-45 kt gusts. Have opted to issue a
short-fused wind advisory for the mountains. Am running this through
12 UTC. Guidance suggests threat may diminish an hour or two earlier
than that, but want to cover whole threat window.
The front itself sags across the forecast area this morning. It`s
moisture starved so am not anticipating any showers (not really even
in the mountains), but there could be some associated cloud cover. A
wind shift to northwest will be the primary indicator of a frontal
passage. Although cold advection will be ongoing after that, so will
downslope flow. MOS overall running fairly consistent, and not much
cooler than yesterday (except for the Potomac Highlands). Have made
no adjustments to current high temperature forecast.
Model sounding suggest that winds will diminish with fropa. Mixing
behind the front supports 25-30 kt-- a breezy day but not headline-
able.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
The gradient will relax a bit and decouple as well. Although the
airmass will be chilly, it will remain well mixed which will impede
radiational cooling. Do not have any frost concerns tonight due to
those winds. The Central Shenandoah Valley may prove to be an
exception, but it would be premature to issue Frost Advisories at
this juncture. Highland and Pendleton even have freeze potential.
That will be placed in the Hazardous Weather Outlook.
Tuesday and Wednesday will be quieter days as high pressure builds.
That will allow for decoupling and radiational cooling Tuesday
night. Hence, there is a strong possibility for areas of frost over
a good portion of the area. Growing seasons could end for some
counties. This too will be placed in the HWO. Temperatures both
days will likely be in the 50s.
Solutions becoming a little more progressive, bringing in isentropic
lift Wednesday night...primarily west of the Blue Ridge. Guidance
has gone more aggressive with POPs, and have included a chance for
overnight rain in the aforementioned areas.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Low pressure will be moving across the southern Great Lakes Thursday
while an associated strong cold front moves through the Ohio Valley.
Southerly flow will increase Thursday and showers are expected to
move from west to east Thursday and Thursday night. Windy conditions
are possible behind the frontal passage. The cold front will move to
the east by late Thursday night/Friday morning and showers will
taper off across the region. Rainfall amounts should stay under a
half inch through Friday. High pressure will briefly move into the
region Friday and Friday night before another low pressure system
moves into the Great Lakes. A cold front should cross the region
this weekend.
Temperatures should be seasonable if not cooler than normal through
the weekend.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
Low level wind shear risk early this morning as a 40-50 kt jet
resides at/above 1500 ft above the surface. Have included comment in
TAFs. Thats the primary concern as VFR conditions will prevail. A
dry cold front will cross the terminals this morning. Winds will
veer northwesterly during the morning push. Behind fropa, mixing
will support gusts 25-30 kt through sunset.
Will still have northwest flow Tuesday, but winds will be on the
order of 10-20 kt during the day, and become light Tuesday night.
A cold front will cross the terminals Thursday-Friday and may cause
flight restrictions.
&&
.MARINE...
Southwest winds on the waters will veer northwest this morning as a
cold front crosses. Small Craft Advisory being realized on the Bay
and lower Potomac. There is a low level jet with higher winds
inland. Do not believe mixing will be present to bring these winds
down.
Behind the front mixing will improve, but winds at that time will be
in the 25-30 kt range. Therefore have maintained SCA for all waters.
Have extended Advisory for the Bay and lower Potomac into Tuesday as
momentum transfer looks like it will support at least minimal SCA
gusts.
A cold front will approach the waters Thursday and SCA possible
Thursday-Friday.
&&
.FIRE WEATHER...
Will have gusty northwest winds today. Where the winds forecast to
be the greatest (gusts up to 30 mph), relative humidity may fall
just above Red Flag criteria (near 40%). Lower RHs will coincide
with less wind. Fuels also look to be on the edge. Will advise
dayshift to consult with Fire Officials this morning. A statement
may prove to be prudent.
&&
.TIDES/COASTAL FLOODING...
Water level currently below astronomical normals. Strong northwest
winds will arrive today, which will be responsible for blow out
tides. Levels could drop greater than a foot below normal.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Wind Advisory until 8 AM EDT this morning for MDZ501.
VA...Wind Advisory until 8 AM EDT this morning for VAZ503-504-507-
508.
WV...Wind Advisory until 8 AM EDT this morning for WVZ501>503-505-
506.
MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ530>534-
537>543.
Small Craft Advisory from 9 AM this morning to midnight EDT
tonight for ANZ535-536.
&&
$$
SYNOPSIS...HTS/HSK
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...HSK
AVIATION...HTS/HSK
MARINE...HTS/HSK
FIRE WEATHER...HTS
TIDES/COASTAL FLOODING...HTS
Area Forecast Discussion
National Weather Service Blacksburg VA
308 AM EDT Mon Oct 24 2016
.SYNOPSIS...
A dry cold front will slide southeast across the mountains this
morning before passing to the south of the area this afternoon.
High pressure builds in behind the front later today into
Wednesday bringing continued dry and cool weather. Another cold
front looks to cross the region on Thursday with the next chance
of showers.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 230 AM EDT Monday...
Deepening upper trough across the northeast U.S. along with northwest
flow aloft will propel a reinforcing cold front through the region
by this afternoon. Main concern continues with stronger westerly
winds just ahead of the boundary this morning, and perhaps with
northwest trajectories for a while behind the front across the
north/west with mixing this afternoon. However given the best jet
aloft early this morning and weakening subsidence this afternoon
as better dynamics pass north, expecting to stay below wind advisory
criteria, but quite breezy/windy espcly northern sections.
Moisture along the front remains quite limited with mostly upslope
aided low clouds that could spill east out to the Blue Ridge this
morning before enhanced post frontal drying occurs. Cant totally
rule out a light shower/sprinkle far northwest mountains as a
shortwave swings by within the upper trough and the better cool
advection develops per latest HRRR but quite iffy. Otherwise
becoming mainly sunny and still rather mild espcly south/east
given lagging cool advection that looks to hang up across the
mountains until later this afternoon. Since this in light of good
downsloping, bumped up highs a good category or more in spots
today with 72-78 east and 61-68 west.
Decent surface ridge builds in behind the front from the northwest
overnight which should allow any lingering upslope clouds to fade and
winds to diminish this evening. However how fast winds decouple and to
what degree remains in question given the parent high still back in the
Ohio Valley around daybreak. Models do attempt to develop a bit of a
bubble high across the mountains where likely to see the deeper valleys
espcly northwest sections lose the gradient for a longer period late.
Also dewpoints look rather low for much frost so given this
combination, cut back frost to more patchy nature in the valleys and
without any advisory headlines at this point. Otherwise mostly clear
with lows ranging from the mid 30s to lower 40s excluding localized
near 30 readings in deepest valleys.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
As of 215 AM EDT Monday...
During the first half of this portion of the forecast, surface high
pressure will dominate the weather pattern our our region.
Concurrently, a broad upper level ridge will strengthen across the
central portion of the United States. A persistent upper low/trough
will continue to spin across the Pacific Northwest. By Wednesday
night into Thursday, a piece of energy from the low/trough across
the Pacific Northwest will eject eastward and push through the top
of the upper ridge.
By Thursday morning, the low will progress eastward from the Great
Lakes region into PA/NY/NJ. Its associated cold front will cross
our area during the day. The latest guidance offers a solution with
a faster arrival and departure times than previously advertised. As
such, have increased the coverage across the western parts of the
area late Wednesday night, and adjusted the peak of coverage across
the area to the forenoon hours Thursday. By late Thursday night,
coverage is expected to be confined to southeast West Virginia
within the upslope flow in the wake of the exiting system.
Average daily temperatures will trend a little cooler through
Wednesday, and then increase slightly Thursday. As a whole, readings
will be near normal for this time of year.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 300 PM EDT Sunday...
An area of weak high pressure builds in behind the front from the
northwest on Friday.
Models are not in agreement with next weekends weather. The GFS
quickly brings the next cold front across the region Saturday. The
ECM has high pressure lingering into Friday night, with a warm
frontal passage Saturday followed by a cold front on Monday.
Temperatures will moderate toward normal on Friday. Next
weekends temperatures will depend on timing of each frontal
passage. For now, will carry seasonal temperatures.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
As of 1250 AM EDT Monday...
Overall VFR expected to prevail overnight through Monday night
with periods of scattered to broken strato-cu along the KLWB-KBLF
corridor tonight into early Monday morning. Bases may lower enough
for brief MVFR cigs espcly across the ridges north/west of
KLWB/KHSP to around KBLF early Monday as a cold front slides
through and weak cool advection develops. Otherwise appears any
low level moisture will finally mix out this afternoon given mixing
of very dry air in place.
Main issue overnight will be increase in low level jet out of the
west, while the surface winds stay lower in speed. This presents
some low level wind shear issues. Will have LLWS in until mixing
occurs along and just behind the front late tonight into Monday
morning.
Behind the front winds should gust at times to 20-25kts, then
weaken again by the end of this TAF period as high pressure builds
in from the northwest Monday night.
Extended aviation discussion...
Tuesday and Wednesday...Potential for river valley fog in the
mountain valleys with local vsby restrictions between 08-14Z each
morning, otherwise widespread VFR.
Thursday...Low pressure is forecast to move across the upper
midwest and into the Great lakes with a surface front crossing the
Ohio Valley. Threat for showers and sub-VFR will be possible
along this front which would impact the central Appalachians by
Thursday. Attm, this does not appear that it will have a
significant impact to our region. Biggest impact would be from
Ohio Valley north into Great Lakes closer to the surface low.
High pressure builds in from the northwest Friday, with potential
MVFR ceilings at BLF/LWB before the high arrives.
&&
.FIRE WEATHER...
As of 300 AM EDT Monday...
Little or no rain has fallen across the northwest North
Carolina Piedmont in the last 14 days. Conditions are becoming
increasingly dry for western North Carolina, espcly just east of
the Blue Ridge. Drying conditions will continue for this region
again today, and for much of the upcoming work week. Passage of a
dry cold front by this afternoon may pose control problems for
any fires in the lee of the Blue Ridge, and especially for areas
which have not seen rainfall. Greatest concern would be from Mount
Airy, North Carolina, and areas to the southwest, including Pilot
Mountain. Wind gusts of 15 to 25 mph are possible into this
afternoon, coupled with humidity minimums in the 20 to 30
percent range which will cause added drying of smaller fuels.
Therefore plan to include a headline for now in the fire weather
forecast as a heads up for low humidity and gusty winds today.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...DS
LONG TERM...RCS
AVIATION...AMS/JH/PM/WP
FIRE WEATHER...JH/PM
Area Forecast Discussion
National Weather Service Las Vegas NV
1127 PM PDT SUN OCT 23 2016
.SYNOPSIS...A Pacific storm system will impact the region tonight
through Monday. This will bring increased cloudiness as well as
chances for rain and isolated thunderstorms. More tranquil weather
is expected during the middle of next week before another series of
storms takes aim at the region late in the week through next weekend.
&&
.UPDATE...Have made updates to the forecast through Tuesday morning
to account for the latest trends and guidance. In the near term
through 5AM I bumped PoPs up slightly for Mohave County where some
light showers have developed. After 5AM made some additional changes
to account for the westward trend in the current band of
precipitation. This band is expected to fall apart sometime mid-
morning. After that time, showers are expected to become more
scattered in nature and gradually diminish from west to east through
the day into Monday night.
&&
.PREV UPDATE...
1010 PM PDT SUN OCT 23 2016
Made some pretty large changes to the PoP/QPF/Wx grids
through 12z. There is much better agreement on the placement of the
band of precipitation, and it will be a bit further west that
previously forecast. Increased to categorical PoPs for the areas
where it is currently raining and where the band is forecast to move
over the next 6-8 hours. Also reduced PoPs to just a slight chance
across most of Mohave, eastern Clark, and eastern San Bernardino
counties. Will continue to monitor and make updates as needed.
&&
.PREV UPDATE...
826 PM PDT SUN OCT 23 2016
Showers are moving through portions for the Mojave Desert this
evening including the Las Vegas Valley and portions of San
Bernardino and Southern Inyo Counties. Isolated thunderstorms have
occurred in the vicinity of Daggett. Gusty winds to 35 mph have been
observed with these showers. Red Flag Warning has been allowed to
expire as moisture has increased across the warned area. Areas of
shower activity will continue well into Monday. This trend is
currently reflected in the forecast so no changed have been made.
&&
.PREV DISCUSSION...
235 PM PDT SUN OCT 23 2016
.SHORT TERM...Through Wednesday Night
As for our current products. Based on latest observations and
guidance having a hard time justifying the Wind Advisory so am going
to cancel that product with the afternoon issuance. It does look
breezy to locally windy this afternoon and Monday in parts of Nye,
Esmeralda and Lincoln Counties but not widespread enough for
headlines.
So far more bark than bite in regards to rainfall. Lots of mid/high
level moisture streaming into the Mojave Desert/Southern Great Basin
but little in the way of dynamics or instability to help generate
any more than virga or probably just a light rain shower at the
higher elevations.
As the air mass continues to undergo moistening from the mid-levels
down to the surface tonight stronger dynamics should start to come
into play as jet noses into Southern California placing much of the
Mojave Desert and southern Nevada under the left front exit region.
Some discrepancy between the operational models and HRRR on exactly
where north/south lines of showers/embedded thunderstorms develop.
The operational models remain consistent developing a line between
the Morongo Valley-Spring Mountains-Caliente. Meanwhile, the HRRR is
further west between Ridgecrest-Beatty-Ely. In the end, both
solutions may turn out correct so did not much change to inherited
POP grids which paint the highest POPs in a corridor between Las
Vegas and Beatty tonight/Monday morning. By Monday afternoon the
lines should start dissipating with showers/thunderstorms becoming
more scattered in coverage under slightly more unstable air mass.
Any residual showers/thunderstorms will come to an end Monday night
as dry/more stable air mass develops under building ridge of high
pressure. High pressure stays in control of our weather regime
Tuesday and Wednesday.
.LONG TERM...Thursday through Sunday.
Southwest flow over the area with high pressure to the east and
troughing to the west on Thursday with extended models in agreement.
However, as with previous model runs differences really start to
show up Friday through the weekend. The ECMWF continues to be the
much faster and more progressive model compared to the slower GFS
and Canadian runs. By Thursday afternoon the ECMWF already has
precipitation reaching the southern Sierra while the other models
don`t bring in it until Friday morning. The one thing that the
models basically agree on is the placement of the main rain band
which stretches from far western San Bernardino County up through
Inyo and eventually across Lincoln County while leaving Clark,
eastern San Bernardino, and Mohave Counties generally dry except for
some light scattered showers. Went ahead and kept the current
rainfall timing alone in the grids due to the continued uncertainty,
but upped the pops for Inyo and Nye Counties with likely in the
higher terrain of Inyo. The southwest flow into the Sierra should
help limit how much rain shadowing occurs with a good possibility of
a decent rain event for Inyo County. Although the timing is off on
the models it looks like much of the precipitation will be out of
the area by Saturday as high pressure quickly reestablishes itself
over the area. This would bring a quicker warming trend back to the
area Saturday and Sunday. Even on Friday with the thicker clouds,
most areas will continue to see slightly above normal temperatures.
&&
.AVIATION...For McCarran...Light winds are expected through the
evening. However, with some of the showers and potential
thunderstorms that will move toward the area its possible that some
stronger winds associated with these storms will move into the
valley. The best window for this happening will be between 02z-08z.
Showers will also be possible in the valley, but thunderstorms look
to remain west and northwest. Cigs down to 8-10K feet overnight.
Scattered showers possible through midday Monday with cigs around
10k feet and south winds increasing to around 10-20kts in the
afternoon.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Scattered showers and thunderstorms expected overnight
and Monday with a drying trend from west to east Monday afternoon.
Cigs around 8-10k feet over most areas. Gusty winds will continue
this evening for Inyo, Esmeralda, and central Nye Counties with
south winds over most areas Monday 10-20kts.
&&
.FIRE WEATHER...Expanded the Red Flag Warning to include Fire Zone
460 as local red flag conditions are being met. Winds will diminish
tonight only to increase again Monday. Humidity levels will be
higher on Monday so there is not threat of Red Flag conditions being
met. Drier and more stable weather is in the forecast Tuesday
through Thursday with unsettled weather returning late in the week
and next weekend.
&&
.SPOTTER INFORMATION STATEMENT...Chances for rain and perhaps
isolated storms will increase on Sunday and Monday. Spotters should
report significant weather according to standard operating
procedures.
&&
$$
Updates (1010 & 1127)...Wolcott
Prev Update...Berc
Short Term/Fire Weather...Pierce
Long Term/Aviation...Gorelow
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter
Area Forecast Discussion
National Weather Service Bismarck ND
900 AM CDT Mon Oct 24 2016
.UPDATE...
Issued at 858 AM CDT Mon Oct 24 2016
Fog persists in the James river valley and current forecast
carries this through 11 am. Otherwise current forecast trending
ok with mainly updates to current conditions.
UPDATE Issued at 622 AM CDT Mon Oct 24 2016
Areas of fog continue over eastern ND but weather cameras and
surface observations over eastern portions of central ND show
little in the way of fog, except for Jamestown which has been
going back and forth between a mile and a quarter mile most of the
night. Currently we are carrying patchy dense fog over this area
through mid morning in the gridded forecast. If fog spreads may
issue a sps but will leave things as is for now. Otherwise no
significant changes to the going forecast.
&&
.SHORT TERM...(Today and tonight)
Issued at 334 AM CDT Mon Oct 24 2016
Focus in the short term is fog and low stratus cloud formation this
morning. Attention then turns to the potential strength of the
southeast winds.
Currently...surface high pressure was over the Red River Valley,
centered over the border of ND/MN. Temperatures had dropped into the
mid 20s/lower 30s there with light winds, and fog had begun to form
over parts of the eastern third of ND, including the Devils Lake
Basin and James Valley. The latest iterations of the short term high
res HRRR model seems to have a good handle on the current area of fog
formation, suggesting that the area along and east of the Coteau is
most at risk for dense fog. This model also suggests the fog will
linger into the later morning hours. After collaborating with Grand
Forks and Aberdeen NWS offices, and noting that web cams not yet
indicating any widespread fog, decided that we will mention patchy
fog north central, and patchy dense fog from the James Valley to the
Devils Lake Basin counties. Should dense fog develop, we can issue a
short term Special Weather Statement to address more widespread low
visibilities.
Meanwhile, at upper levels a strong ridge was established over the
Rockies. This upper level ridge axis is forecast to move east into
the Dakotas tonight. Broad surface low pressure over the Rockies,
and high pressure moving east today will allow southeast winds to
develop. A strong low level h925/h850 jet is forecast to develop
from the southern Plains northward into Saskatchewan by this
afternoon. Expecting southeast winds to be a bit stronger than the
model blends, and raised wind speeds to 15 to 20 mph with gusts to
25 mph - beginning late this morning and continuing through the
afternoon. Bufkit soundings indicate that the low level jet remains
strong tonight and possibly continues to mix out at the surface at
times, but noted that a low level inversion develops and may keep
the higher winds aloft from mixing. Confidence is not high enough to
keep those higher wind speeds mentioned tonight.
.LONG TERM...(Tuesday through Sunday)
Issued at 334 AM CDT Mon Oct 24 2016
Focus in the long term is on the chances for rain Tuesday into
Wednesday.
The upper level ridge over the Dakotas Monday night begins to
flatten out as it moves east. Southwest flow aloft becomes
established over the Rockies with a large-scale upper level low off
the west coast. A shortwave emerging from the 4-corners area moves
northeast through the flow Monday night and reaches the Dakotas
Tuesday morning. This wave will bring an increase of mid level
moisture, and lifting associated with the established low level jet
will result in rain showers over central and eastern ND. At this
time it appears that the James Valley and into eastern ND are poised
to receive the bulk of the rainfall...with the possibility of
anywhere from 0.10 to 0.50 inches of rain.
Another shortwave emerging from the west coast system emerges from
the Pacific Northwest on Tuesday and reaches southern Saskatchewan
Tuesday night/Wednesday morning. Today`s model runs suggest that
showers from this wave will remain north of the Canadian border on
Wednesday.
The western ridge builds back over the Rockies Thursday, with yet
another series of shortwave breaking down the ridge. Models are not
in good agreement regarding the timing and track of these
shortwaves. Model consensus suggests keeping any mention of
precipitation out of the forecast for the end of this week, with
only slight chance mentions on Saturday.
Continued mild with highs in the 50s and 60s this week. A cooler
weekend ahead with highs in the 40s and 50s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 622 AM CDT Mon Oct 24 2016
IFR cigs/vsbys continue at KJMS at 11 UTC. Will carry IFR fog/cigs
through 16 UTC. Farther west, HRRR has been keying on low stratus
over central ND since before 06 UTC. Nothing had developed all
night long but just at 11 UTC KHEI reported a ceiling of 200 ft.
Hard to tell on fog loop with high clouds over the area but there
may be some more patchy stratus starting to develop. Will take
one last look but might just carry a scattered ifr layer, with no
ceiling to hint at the possibility if ifr cigs until we see
something more definitive. HRRR has this low stratus through
around 15-16 UTC before burning off. Otherwise today after any
fog/stratus burns off this morning, we expect VFR conditions with
mainly mid and high level clouds and an increasing southeast flow,
becoming gusty this afternoon. A system moves in late tonight with
perhaps a few showers at KBIS and KJMS after 06 UTC but ceilings
are forecast to remain VFR through 12 UTC Tuesday. Ceilings do
appear to lower rapidly across central ND after 12 UTC Tuesday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...JV
LONG TERM...JV
AVIATION...TWH
Area Forecast Discussion
National Weather Service Goodland KS
518 AM MDT Mon Oct 24 2016
.SHORT TERM...(Today through Wednesday Night)
Issued at 241 AM MDT Mon Oct 24 2016
Early morning WV imagery and RAP analysis shows large scale
ridging continuing to dominate the pattern across the central
US. At the surface as front is stalled along the front range, with
high pressure centered over the northern Mississippi River Valley
extending south and west towards our CWA.
H5 ridge flattens as a shortwave trough (currently over the Pacific
NW) propagates eastward through the Northern Plains then through
central KS Tuesday-Tuesday night. Ridging then rebuilds over the
Central Rockies and Plains Wednesday. While temps are slight cooler
today (upper 60s/lower 70s) they are still above normal (by about
10F)...and temps will only trend upwards over the next few days.
This pattern will tend to keep very dry conditions in place through
these periods.
Return flow ahead of this upper level shortwave trough and
associated (weak) cold front is still advertised tonight and
Tuesday morning, and should bring bountiful BL moisture to our
CWA. SREF/NAM/ARW/NMM all show fog/stratus developing and there is
potential for dense fog to develop as moisture pools along the
prefrontal surface trough. Drier BL air may begin to move eastward
due to shift in flow to the southwest behind surface trough, which
could help erode the western extent of the fog/stratus or help
clearing from the west to the east. For now I kept fog mention in
place with no major changes midnight tonight through Tuesday
morning.
Regarding shower/thunderstorm chances Tuesday: The upper
level shortwave trough and H3 jet streak that move through our
region Tuesday will lead to good forcing in our east. Air mass below
600mb remains dry, and main CAPE axis will remain ahead of of
surface trough. This surface trough would also act as main focus for
initation Tuesday afternoon/evening and guidance continues to trend
eastward. Due to limited instability in our east and the very dry
low levels confidence is low in any measurable showers or
thunderstorms. Guidance still has a very small area in our
southeast, but considering trends I wouldn`t be surprised if even
this is pulled east with next run of models.
.LONG TERM...(Thursday through Sunday)
Issued at 241 AM MDT Mon Oct 24 2016
H5 ridge dominates the long term pattern with above normal
temperatures and generally dry weather. Northwest flow aloft on
Thursday will become westerly as the ridge axis pushes eastward
out of the central Rockies and into the central Plains on
Friday. A deep trough will traverse the northern Plains and the
southern Canadian Plains Friday afternoon and turn the upper flow
northwestward once more. No precipitation is expected as the
associated weak cold front and trough traverse the region. The
ridge amplitude increases as we head into Saturday and Sunday with
dry conditions continuing into the beginning of next week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 518 AM MDT Mon Oct 24 2016
VFR conditions will prevail through this evening, with the main
aviation concern during the day being 12-18kt winds during the
afternoon at both terminals. Fog and stratus is expected to
develop after midnight, with IFR conditions likely at both KGLD
and KMCK by 12Z Tuesday morning. VLIFR conditions are possible if
dense fog develops as a lot of guidance is beginning to indicate.
There will be drier air to the west trying to filter eastward
towards KGLD and then eventually KMCK, so I am not confident that
VLIFR conditions will prevail at this point. Subsequent updates
will be able to fine tune the timing/duration of these lower
conditions as confidence increases and the fog/stratus event is
closer in time.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...DR
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1026 AM EDT Mon Oct 24 2016
.SYNOPSIS...
A dry cold front will cross the Carolinas today from the northwest.
In the front`s wake, strong high pressure will quickly build back
over the region and linger through the middle of the week. Another
frontal passage is expected on Thursday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1020 AM EDT: The main adjustment to the forecast this morning
has been for hourly temperature trends in areas just in the lee of
the mountains - where mixing and downsloping have led to fast
warming. Otherwise, the forecast remains on track with a dry
backdoor cold front expected to slip southward across the NC
Foothills and Piedmont during the late morning to midday period,
passing across Upstate SC during the early afternoon. Sfc winds will
veer as the front approaches through late morning. Only a few cirrus
clouds will be possible with the passage of the front. The timing of
weak CAA in the wake of the front will favor temps climbing up to
two categories above normal, but still well below records. High
pressure will build back in from the NW behind the front tonight,
but temps are not expected to be as cool as the air mass was behind
the last front. At this point, the frost threat looks minimal.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 305 am Monday, the short term fcst picks up at 12z on Tuesday
with broad upper trofing gradually moving off the New England Coast
as upper ridging slowly spreads farther east in the trof`s wake. The
guidance suggests that the ridge will deamplify as it spreads
eastward resulting in a more zonal pattern over the fcst area for
much of the period. By early Thurs, another upper trof will begin to
develop to our NW as the upper ridge amplifies over the Western
CONUS. At the sfc, a reinforcing Canadian high will be spreading
over the region by early Tuesday bringing more dry air to the
Carolinas. As the center of the high slides farther SE late Tues and
into Wed, a weak wedge pattern will briefly develop over the CWFA.
This pattern won`t persist for long as the next cold front will move
into the area by early Thurs and break down any lingering wedge
bndy. As for the sensible fcst, we can expect a dry fcst thru
Wednesday with POPs ramping up from the west as the front approaches
early Thursday. Temps should remain near, if not just below, normal
for late October on Tues and Wed.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 255 am Monday: the medium range fcst picks up at 12z on
Thursday with a fairly progressive upper lvl pattern expected thru
the period. By early Thurs, an upper trof axis will be crossing to
our north as strong upper ridging dominates the Western CONUS.
As we move into Friday, the upper trof is expected to lift NE and
up over New England as more zonal flow briefly sets up over our
region. Beyond this point, the long range models differ significantly
wrt the upper pattern evolution. The latest 00z GFS digs another,
deeper upper trof down across the Eastern CONUS over the weekend
and then develops an embedded H5 shortwave in the trof`s wake early
Monday. The 12z ECMWF keeps relatively zonal flow over the southeast
well into Sunday and then generates a stronger looking H5 shortwave
over the Northern Plains and moves it across the fcst area by early
Monday.
At the sfc, a cold front will be moving into the CWFA from the west
Thursday morning. Models indicate a fairly quick fropa with weak
reinforcing high pressure moving in behind the front by late Thurs/
early Friday. Beyond this, the models diverge with the GFS bringing
another cold front down from the Great Lakes on Sat with strong high
pressure overspreading the region after the fropa and lingering well
into next week. The ECMWF is much slower developing a low and and does
not bring its associated front to our doorstep until late Sun/early
Monday. As for the sensible fcst, no significant changes were made
owing to the pattern uncertainty beyond Friday. I kept slight to solid
chance POPs for Thurs and early Fri with the best chances over the
higher terrain and foothills with forecasted QPF amounts remaining below
0.5 inches.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR conditions expected through the TAF
period. A dry cold front will slide southward across the western
Carolinas during the afternoon, complicated by the development or
presence of a lee trof. With little moisture to work with, only a
wind shift is expected with the fropa. Winds will shift from SW to W
or WNW by midday, then veer further to NW this evening. The biggest
problem will be a cross-wind at KCLT through the middle part of the
day. Have opted to keep wind direction WSW thru much of the daytime
hours because of the lee trof, with a shift to WNW after 18Z based
on LAMP and RAP guidance. Only a few wisps of cirrus will stream by
from the west periodically through the period. The other trouble
spot has been KAVL. Strong winds aloft this morning above a strong
temperature inversion resulted in a few hours of low level wind
shear. However, the shear now appears to be going away as the
boundary layer continued to deepend and NW gusts begin.
Outlook: Dry high pressure will persist over the Southeast through
Wednesday. Then a fast-moving cold front will cross the area
Thursday or Thursday night, but with limited moisture. Dry
conditions return for next weekend.
Confidence Table...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% High 100% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...JPT
NEAR TERM...HG/PM
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...HG/PM
Area Forecast Discussion
National Weather Service Blacksburg VA
711 AM EDT Mon Oct 24 2016
.SYNOPSIS...
A dry cold front will slide southeast across the mountains this
morning before passing to the south of the area this afternoon.
High pressure builds in behind the front later today into
Wednesday bringing continued dry and cool weather. Another cold
front looks to cross the region on Thursday with the next chance
of showers.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 230 AM EDT Monday...
Deepening upper trough across the northeast U.S. along with northwest
flow aloft will propel a reinforcing cold front through the region
by this afternoon. Main concern continues with stronger westerly
winds just ahead of the boundary this morning, and perhaps with
northwest trajectories for a while behind the front across the
north/west with mixing this afternoon. However given the best jet
aloft early this morning and weakening subsidence this afternoon
as better dynamics pass north, expecting to stay below wind advisory
criteria, but quite breezy/windy espcly northern sections.
Moisture along the front remains quite limited with mostly upslope
aided low clouds that could spill east out to the Blue Ridge this
morning before enhanced post frontal drying occurs. Cant totally
rule out a light shower/sprinkle far northwest mountains as a
shortwave swings by within the upper trough and the better cool
advection develops per latest HRRR but quite iffy. Otherwise
becoming mainly sunny and still rather mild espcly south/east
given lagging cool advection that looks to hang up across the
mountains until later this afternoon. Since this in light of good
downsloping, bumped up highs a good category or more in spots
today with 72-78 east and 61-68 west.
Decent surface ridge builds in behind the front from the northwest
overnight which should allow any lingering upslope clouds to fade and
winds to diminish this evening. However how fast winds decouple and to
what degree remains in question given the parent high still back in the
Ohio Valley around daybreak. Models do attempt to develop a bit of a
bubble high across the mountains where likely to see the deeper valleys
espcly northwest sections lose the gradient for a longer period late.
Also dewpoints look rather low for much frost so given this
combination, cut back frost to more patchy nature in the valleys and
without any advisory headlines at this point. Otherwise mostly clear
with lows ranging from the mid 30s to lower 40s excluding localized
near 30 readings in deepest valleys.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
As of 215 AM EDT Monday...
During the first half of this portion of the forecast, surface high
pressure will dominate the weather pattern our our region.
Concurrently, a broad upper level ridge will strengthen across the
central portion of the United States. A persistent upper low/trough
will continue to spin across the Pacific Northwest. By Wednesday
night into Thursday, a piece of energy from the low/trough across
the Pacific Northwest will eject eastward and push through the top
of the upper ridge.
By Thursday morning, the low will progress eastward from the Great
Lakes region into PA/NY/NJ. Its associated cold front will cross
our area during the day. The latest guidance offers a solution with
a faster arrival and departure times than previously advertised. As
such, have increased the coverage across the western parts of the
area late Wednesday night, and adjusted the peak of coverage across
the area to the forenoon hours Thursday. By late Thursday night,
coverage is expected to be confined to southeast West Virginia
within the upslope flow in the wake of the exiting system.
Average daily temperatures will trend a little cooler through
Wednesday, and then increase slightly Thursday. As a whole, readings
will be near normal for this time of year.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 300 PM EDT Sunday...
An area of weak high pressure builds in behind the front from the
northwest on Friday.
Models are not in agreement with next weekends weather. The GFS
quickly brings the next cold front across the region Saturday. The
ECM has high pressure lingering into Friday night, with a warm
frontal passage Saturday followed by a cold front on Monday.
Temperatures will moderate toward normal on Friday. Next
weekends temperatures will depend on timing of each frontal
passage. For now, will carry seasonal temperatures.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
As of 645 AM EDT Monday...
Weak cold front pressing in from the north/northwest should push
across the mountains this morning and elsewhere during the
afternoon if not sooner. Given dry air in place, still expecting overall
VFR to prevail today and tonight. Could continue to see periods
of scattered to broken strato-cu near the KLWB-KBLF corridor, along
and espcly behind the front as cool advection/upslope kick in
through early this afternoon. However expecting most of this
canopy to have bases above 3k feet before all moisture mixes out
later this afternoon given mixing of very dry air behind the
front.
Main issue continues with the lingering low level jet early this
morning and subsequent wind shear per near calm surface winds in
spots to start. Guidance suggests enough weakening of the winds
aloft combined with mixing to help alleviate wind shear issues by
mid or late morning. Thus will keep LLWS in until mixing occurs
along and just behind the front by later this morning.
Behind the front winds should gust at times to 20-25kts, then
weaken again by the end of the day as high pressure starts to
build in from the northwest by tonight.
Extended aviation discussion...
Tuesday and Wednesday...Potential for river valley fog in the
mountain valleys with local vsby restrictions between 08-14Z each
morning, otherwise widespread VFR.
Thursday...Low pressure is forecast to move across the upper
midwest and into the Great lakes with a surface front crossing the
Ohio Valley. Threat for showers and sub-VFR will be possible
along this front which would impact the central Appalachians by
Thursday. Attm, this does not appear that it will have a
significant impact to our region. Biggest impact would be from
Ohio Valley north into Great Lakes closer to the surface low.
High pressure builds in from the northwest Friday, with potential
MVFR ceilings at BLF/LWB before the high arrives.
&&
.FIRE WEATHER...
As of 300 AM EDT Monday...
Little or no rain has fallen across the northwest North
Carolina Piedmont in the last 14 days. Conditions are becoming
increasingly dry for western North Carolina, espcly just east of
the Blue Ridge. Drying conditions will continue for this region
again today, and for much of the upcoming work week. Passage of a
dry cold front by this afternoon may pose control problems for
any fires in the lee of the Blue Ridge, and especially for areas
which have not seen rainfall. Greatest concern would be from Mount
Airy, North Carolina, and areas to the southwest, including Pilot
Mountain. Wind gusts of 15 to 25 mph are possible into this
afternoon, coupled with humidity minimums in the 25 to 35 percent
range which will cause added drying of smaller fuels. Therefore
plan to include a headline for now in the fire weather forecast as
a heads up for low humidity and gusty winds today.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...DS
LONG TERM...RCS
AVIATION...AMS/JH/PM/WP
FIRE WEATHER...JH/PM
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php
Area Forecast Discussion
National Weather Service Duluth MN
322 PM CDT Mon Oct 24 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 322 PM CDT Mon Oct 24 2016
High pressure over the Northland will result in another night of
mostly clear skies and light wind speeds, so it will be another
cold night. The relatively low humidity, with dew point
temperatures in the 20s and low 30s as of this afternoon, suggest
temperatures will plummet after sunset. However, a little
concerned about increasing upper-level cloud cover later in the
night associated with blow off from low pressure and shortwaves in
the western US, which will be moving into the Plains overnight
into Tuesday. Therefore, refrained from the coldest model
guidance. May need to lower temperatures, with an update this
evening, if it looks like it will take longer for the upper-level
cloud cover to spread over the Northland. There be enough
relatively humidity amidst the strong radiational cooling later
tonight, and light enough wind speeds, to result in patchy fog for
the lower-lying areas of northwest Wisconsin and the
Arrowhead and Iron Range.
Otherwise, easterly flow will develop overnight with the passing
high pressure, and the flow will pick up in speed during the day
Tuesday. Increasing cloud cover will limit highs to the middle 40s
to low 50s. Strong east to northeast flow will develop over
western Lake Superior during the afternoon and going into the
evening, in response to the approaching low pressure, and that
wind will translate to the Twin Ports area. There could be gusts
of 20 to 25 mph by the late afternoon.
This area of low pressure will be bringing our next round of rain.
However, it will take some time for the rain to move into our
territory because of the relatively dry east to east-southeast
flow. Some of the rain will go into saturating the atmosphere. It
may reach the far southwest forecast area by evening.
.LONG TERM...(Tuesday night through Monday)
Issued at 322 PM CDT Mon Oct 24 2016
A shortwave trough will dig across the Northern Plains into
northern Minnesota at the beginning of the extended. This feature
will move into the central Great Lakes by Wednesday evening. Still
some differences between the latest guidance, with most notably
the ECMWF coming in with a weaker shortwave. At the surface, this
will develop an area of low pressure across Iowa, which will move
eastward into southern Wisconsin by Wednesday evening. This will
bring rain to much of the Northland Tuesday evening through
Wednesday. Tuesday night lows will generally be in the 30s
throughout the Northland. Highs on Wednesday will top out in the
low to mid 40s.
Rain will taper off across much of the forecast area Wednesday
evening into early Thursday morning. Light precipitation chances
will continue across northern Minnesota and eastern Wisconsin
Wednesday evening into Thursday morning as another shortwave
trough dives southeastward from Saskatchewan into western Lake
Superior. Behind the shortwave, weak high will gradually build
into the area. On the western side of the ridge, will see a
gradual warm up for Thursday and Friday as southwesterly warm
advection occurs at 850 hPa.
Will see another shortwave eject from the Pacific Northwest and
late on Thursday and into the Northern Plains by Friday. The
latest ECMWF again features a more subtle shortwave in comparison
to the GFS/GEM. Will see 850 hPa temps between 0C to +5C, so
expecting mainly rain Friday. As the system exits on Saturday will
see cooler northwest flow bringing -5C to 0C air into the
Northland. With the cool northwest flow behind low, kept some
lingering low chances of light precipitation into Saturday morning
as hinted by the latest GFS. Late in the weekend and early next
week a ridge of high pressure will build into the Northern Plains.
The latest GFS/ECWMF bring another round of warm air advection due
to southwesterly flow at 850 hPa. Once again it appears there will
another brief warm up Sunday/Monday before the next system moves
in on Tuesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1235 PM CDT Mon Oct 24 2016
VFR conditions will continue through early this evening across
the area as a surface ridge of high pressure slides eastward. An
area of VFR stratus was found over northwest Ontario and portions
of southeast Manitoba this morning. Some of the higher resolution
models, including the HRRR and NAM, suggest those clouds will move
into the INL vicinity this afternoon and linger into this evening.
Winds will go calm for a time tonight at all terminals before
veering east to southeasterly for Tuesday. With veering winds at
INL, think the stratus will retreat northwestward into northwest
Ontario by 25.10Z. An approaching shortwave trough of low pressure
will bring a high cirrus layer into the area overnight. Meanwhile,
the period of clear skies and calm winds may result in areas of
fog. Should the mid and high clouds arrive earlier, the fog
potential would diminish. As winds over western Lake Superior veer
east and southeasterly after 25.08Z, low-level moisture at HYR and
DLH should increase. Think there is a potential for the
development of an MVFR stratus deck at both terminals, but
confidence is lower at HYR since trajectories required are more
complicated. Stratus deck should advect northeast into the
Arrowhead, eventually reaching HIB and possibly INL Tuesday
morning.
Confidence in this forecast package is above average through
25.02Z and average thereafter. Greatest concerns are visibilities
with fog development overnight and timing MVFR stratus
development.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 33 47 38 43 / 0 10 70 70
INL 31 48 37 44 / 0 0 40 60
BRD 35 49 40 45 / 0 50 80 60
HYR 31 50 40 44 / 0 10 80 70
ASX 33 50 38 45 / 0 10 60 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
SHORT TERM...Grochocinski
LONG TERM...Huyck/WL
AVIATION...Huyck
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
445 PM EDT Mon Oct 24 2016
.SHORT TERM...(This evening through Tuesday night)
Issued at 445 PM EDT MON OCT 24 2016
19z sfc analysis shows a dry and mostly cloud free cold front
settling through eastern parts of the state. This boundary is
switching winds more completely to the north at 10 to 15 kts.
Plenty of sunshine on either side of the front has led to near
normal temperatures in the mid to upper 60s north to the mild
lower 70s south while dewpoints were able to mix down into the
upper 30s and lower 40s this afternoon.
The models are in good agreement aloft through the short term as
they all depict a broad trough lifting northeast and out of the
area. This will allow heights to rise for Kentucky through
Wednesday morning while energy and the next developing trough over
the plains stay well north of the area. Accordingly, will favor
the blended model solution with a lean toward the higher
resolution HRRR and NAM12 versions along with the co-op MOS
guidance.
Sensible weather will feature a clear and cool night, especially
after the post frontal winds die off. This will lead to a minor
ridge to valley temperature difference tonight and a more
significant one on Tuesday night as the sfc high shifts off to the
east. This will allow for some patchy frost to develop in isolated
spots of the deepest valleys both nights, though limited by the
dry air expected Tuesday night. As such, the vast majority of the
area of will stay frost free for another week. Additionally, both
nights could see some patchy fog along the rivers towards dawn.
Another pleasant and mostly sunny day can be expected for Tuesday
with highs similar to today - warmest southwest and 5 to 10
degrees cooler northeast.
Started with the CONSShort/ShortBlend for the bulk of the grids
with adjustments to the night-time temps revolving around terrain
differences, as well as knocking dewpoints down in the afternoon
and again Tuesday night. PoPs were again zeroed out through the
period - in line with all guidance.
.LONG TERM...(Wednesday through Monday)
Issued at 325 PM EDT MON OCT 24 2016
The extended period will feature a series of shortwaves embedded in
the northern stream moving through the Ohio Valley. The first
shortwave will make its way from the central plains across the Great
Lakes late Wednesday night/Thursday, dragging a cold frontal
boundary through Eastern Kentucky. This system will bring our next
chance for precipitation by dawn on Thursday. However, operational
models have continued to back off on the QPF potential with this
frontal passage so most locations will only see a tenth of an inch
or less.
The upper level pattern becomes a bit messy beyond Friday with
several additional impulses dropping through the Ohio Valley in west-
northwest flow. Differences exist between the GFS and ECMWF with how
far south and how strong these impulses become so have remained
close to the CR Superblend solution from Saturday forward. That
being said, there is the potential for a few showers Saturday
afternoon and evening and again late Sunday night. Ridging builds
back into the Tennessee Valley on Monday setting the stage for a few
more days of dry and mild weather.
Temperatures will remain near seasonable values through the period
with highs in the upper 60s and low 70s. Morning lows will vary a
bit more with potential cloud cover and passing showers. But most
mornings, lows should be near climatology, in the mid and upper
40s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 230 PM EDT MON OCT 24 2016
Aside from some scattered clouds with the front at 3-4k feet, VFR
conditions will continue through Tuesday afternoon. Winds will be
up between 5 and 10 kts through this fropa with a turn more
northerly. Look for the winds to subside to light and variable
after 23z and pick up again from the north on Tuesday at around 5
kts.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JVM
AVIATION...GREIF
Area Forecast Discussion
National Weather Service Marquette MI
432 PM EDT Mon Oct 24 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 404 PM EDT MON OCT 24 2016
WV imagery and RAP analysis indicated nw mid/upper level flow
through the nrn Great Lakes between a trough from ern Canada into
New England and a ridge from the srn plains into Saskatchewan. At
the surface, a ridge extended from Manitoba into the Upper MS valley
resulting in anticyclonic nw flow into Upper Michigan. Although 850
mb temps around -6C (water temps near 11C) provided enough
instability for isolated lake effect rain showers over the east,
with daytime warming and an influx of drier air, the pcpn has
diminished this afternoon.
Tonight: As high pressure continued to build into the region,
veering winds to the nne and 850 mb temps remaining near -6C will
push the lake effect westward toward n cntrl Upper Michigan.
Inversion heights near 4k-5k ft and continue acyc flow will limit
intensity. Wet-bulb zero heights suggest pcpn will remain mainly as
rain. Otherwise, mostly clear skies inland west will allow temps to
fall into the upper 20s. Temperatures in the lower 30s are expected
over the rest of the cwa.
Tuesday: Confluent mid upper level flow, high pressure building over
the region with low level dry air, and inversion heights lower to
near 3k ft will bring an end to the lake effect pcpn by afternoon.
However, the 925-850 mb thermal trough will remain close enough to
support extensive stratocu development keeping highs in the mid 40s
north and upper 40s south.
.LONG TERM...(Tuesday night through Monday)
Issued at 432 PM EDT MON OCT 24 2016
Surface ridge will slowly lift northeast away from the Great Lakes,
allowing flow to turn easterly by late Tue night. Guidance continues
to prog a shallow channel of moisture lingering overhead Tue ngt
into Wed, but feel this is likely overdone and could end up with
less shallow cloud cover Tue ngt. Upstream weak diffluent flow
across the upper midwest will slow the arrival of a mid-lvl
shortwave from pushing into the Dakotas until early Wed.
This should all point towards precip not arriving over the Western
Upper Pensinula until after midnight, and that too could be slower
due to a weak downstream mid-lvl ridge over eastern Quebec. Wed
morning the diffluent flow will begin to weaken, allowing the
surface wave to strengthen across Iowa and produce a much tighter
pressure gradient along the lee-side lifting north from Wisconsin
towards Upper Peninsula. But the challenge will be on timing of
cloud cover which could dampen the mixing of higher winds to the
surface Wed. Profile will be moistening more Wed morning, with
thermal profiles showing considerable cool air within the column and
could support light snow mixing with rain. Accumulations should be
difficult given the warm surface conditions; however, could see some
minor slushy mix on grassy surfaces along the eastern forecast area
with temps struggling to warm from the mid/upr 30s to lower 40s.
The shortwave will be slow to push through the forecast area Wed
ngt, and with a downstream weak ridge in place, this could result in
a longer duration of a rain/snow mixture early Thur before the
profile should warm enough to push it over to all liquid p-type.
Current thinking is that temps will be cooler for Thur highs, and
could see the lower 40s trending into the upper 30s away from the
marine environment.
The trough axis will then push east Thur ngt/Fri, with ridging
returning to the upper midwest and eventually the Northern Great
Lakes Fri. This may only be short-lived as operational guidance is
indicating the Pac-NW system will be lifting north through the
Canadian Rockies and arriving over the Upper Midwest/Great Lakes
late Fri/early Sat. In between the mid-week system and weekend
system, temps could rebound into the lower 50s before turning colder
and into the low/mid 40s. Confidence in the extended periods for
Sat/Sun is low at this time, given the spread amongst ensemble
forecasts.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 712 AM EDT MON OCT 24 2016
Lake clouds will linger today bringing MVFR to VFR ceilings across
the area today. Drier air moves in this afternoon and should
decrease the cloud cover. Lake clouds could roll back into SAW late
tonight as winds shift from NW to N-NE over Lake Superior.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 406 PM EDT MON OCT 24 2016
Winds will remain below gales through the period. A tightening
gradient between a deep low pressure system moving through Quebec
and a high pressure ridge building into the Plains will lead to NW
winds gusting to 30 knots over eastern Lake Superior into this
evening. High pressure will then build across the area overnight
into Tuesday, keeping winds generally light across Lake Superior.
Southeast winds will increase again to 20 to 30 knots Wednesday into
Wednesday evening as a low pressure system passing just south of the
area. There will be a trough passage on Thursday but winds should
still remain fairly light. Friday will see south winds increase to
20 to 30 knots again over the east half of Lake Superior as another
low pressure system approaches from the Northern Plains.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Beachler
AVIATION...Voss
MARINE...JLB
Area Forecast Discussion
National Weather Service Phoenix AZ
231 PM MST MON OCT 24 2016
.SYNOPSIS...
A low pressure system northwest of the region continues to draw a
considerable amount of subtropical moisture into the Desert
Southwest. This will lead to a threat of isolated showers and
thunderstorms through tonight. Drier and warmer conditions will
return by the middle of the week.
&&
.DISCUSSION...
Latest MRMS shows isolated showers and thunderstorms across northern
Arizona struggling to backbuild southwestward into the deeper
moisture (PWATs > 1.0 inch). Meanwhile, an anomalous jet streak (95th
percentile) across the Baja Peninsula precedes a southern-stream
short-wave trough further west in the Eastern Pacific. Mostly cloudy
skies have persisted throughout the day across much of the Desert
Southwest which has limited diabatic heating and subsequent
instability.
Conditions will become more favorable for precipitation to develop
this afternoon and this evening as the low pressure system tracks
eastward. Best chance for showers and even a thunderstorm will be
later this afternoon and this evening across La Paz, northern
Maricopa and southern Gila County where favorable upslope flow from
the approaching jet and vorticity forced ascent ahead of the trough
are maximized. Hi-res WRFs including the latest runs of the HRRR
indicate that any rain that develops will be quite light. Low-
reflectivity depiction in the models also suggests sprinkles are
certainly possible as well. With instability lacking, the chance for
a thunderstorm will be slim, however given the cooler temperatures
aloft, negative LIs suggest the potential for an isolated in-cloud
flash.
&&
.PREVIOUS DISCUSSION...
Much drier air aloft will overtake the region from west to east
starting late this evening as the jet max shifts into New Mexico.
Low level moisture will remain over most of Arizona into Tuesday
which may give rise to a few showers or maybe a thunderstorm over the
higher terrain of east-central Arizona. Flow aloft turns out of the
northwest as upper level ridging pushes northward out of Mexico.
500mb heights rebound quickly with 585dm heights already over the
area by Tuesday afternoon. This will lead to another warming trend
for the middle of this week. Highs may approach record levels in some
areas with readings likely topping out into the 90-95 degree range
starting Wednesday. This upper level ridge will get displaced
slightly to the east late Thursday into Friday as a strong upper
level low moves east northeastward toward the central California
coast. Much of the moisture with this system will remain over
California with only slight chances of showers over southeast
California. The displaced upper level ridge is forecast to remain
just to our east through the coming weekend keeping temperatures well
above normal with little to no chance of any rain.
&&
.AVIATION...South-Central Arizona including KPHX, KIWA, and KSDL:
Southeast California/Southwest Arizona including KIPL and KBLH:
Moisture from a pacific weather system that is passing to the west
and north of the region to keep mid and high level cloud decks over
the terminals through this evening, with skies clearing later
tonight and Tuesday, as drier air begins to move back into the
region from the west and north. Along with the cloudiness this
evening, a few showers and thunderstorms are also expected to
develop, especially over south-central AZ, but coverage/confidence
is too low at this time to include anything more than VCSH in the
PHX area tafs at this time. Winds to remain mainly on the light
side, 8 kts or less, following typical diurnal trends, with just a
remote chance of brief stronger winds from shower/thunderstorm
outflows.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Monday...
High pressure redeveloping over the Desert Southwest will bring dry
conditions and well-above normal temperatures to the region on
Thursday. Another weather system brushes the Desert Southwest from
Friday into early Saturday for an increase in humidities and a
slight chance of showers over SE CA. Warmer and drier weather is
expected to return for next Sunday. Yet another pacific weather
system brushing by to the west and north will bring cooler
temperatures and an increase in winds/humidities from Sunday night
into next Monday. Minimum humidities to remain mainly in the 15 to
25 percent range through the entire period, with overnight
recoveries in the good range.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...Percha
FIRE WEATHER...Percha
Area Forecast Discussion
National Weather Service Charleston WV
401 PM EDT Mon Oct 24 2016
.SYNOPSIS...
High pressure mid week. Strong cold front Thursday. Another cold
front Saturday.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 130 PM Monday...
Post frontal stratocu in abundance across the area as CAA aloft
commences. It will be a chilly night tonight and with high
pressure trying to nose in from the northwest, frost possibilities
arise. However, as if often the case around these parts, nothing
is never clear cut. There is considerable concern for stratocu to
linger across the northern WV mountains and adjacent lowland
counties overnight in northwest flow. This is backed up by various
model soundings including HRRR low level profile. Experience
warrants this concern and thus frost may be mitigated across
aforementioned locations. Further to the south and west, this
should not be much of a concern so that areas of frost are likely
across portions of southeast OH and central WV with patchy frost
across the cold spots in northeast KY and elsewhere. After
coordination with surrounding offices, elected to hoist a frost
advisory for most of southeast OH and extending east into central
WV, while leaving out the mountains for the above reasoning.
Tuesday is shaping up to be a stellar Autumn day with just some
passing high clouds as temps run a little below normal for this
time of year, mainly across the north.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 400 PM AM Monday...
A high pressure system will give way to a warm front Tuesday night.
Timing of the clouds and winds with this boundary could be critical
in regards to frost occurring. Based on current models, best
chances of frost will be in the northern and eastern WV counties.
Next rain producer arrives as a strong cold front on Thursday.
Models in fairly decent agreement, so expect only minor timing
changes.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 400 PM Monday...
Good cold air advection behind Thursday`s cold front could provide
some lingering light precipitation or drizzle into Friday.
Yet another front could arrive on Saturday, with precipitation or
drizzle once again possibly lingering into Sunday. Confidence in the
timing of this system is significantly lower compared to Thursday.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
As of 130 PM Monday...
Gusty northwest winds around 20 kts will continue thru 21Z before
subsiding. Post frontal stratus will dissipate across southern
terminals this evening but linger most of the night for the
northern sites to include KEKN and KCKB, but should continue to
remain VFR. This should mitigate fog at EKN overnight. Guidance
indicates enough of a dewpoint spread to mitigate fog elsewhere
and with the lack of a strong low level inversion, have left fog
out elsewhere as well.
Tuesday will feature a light northwest flow aloft and north flow
at the surface. Just some passing high clouds are expected.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: Medium tonight and high tomorrow.
ALTERNATE SCENARIOS: Should stratus dissipate overnight, then
dense fog is likely at KEKN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY
OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL
INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT
ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH
MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE
MODEL.
UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M L M H H H H H H H M M
HTS CONSISTENCY H H H H H H H H H H M M
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY L L L L H H H H H H M M
PKB CONSISTENCY L L M M H H H H H H M M
CKB CONSISTENCY M M M M H H H H H H M M
AFTER 18Z TUESDAY...
IFR in valley fog possible Wednesday mornings. Brief IFR possible in
showers Thursday.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Frost Advisory from 3 AM to 9 AM EDT Tuesday for WVZ008>011-
016>020-027>029.
OH...Frost Advisory from 3 AM to 9 AM EDT Tuesday for OHZ066-067-
075-076-084-085.
KY...None.
VA...None.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...30