Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/05/16
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1152 PM EDT Fri Nov 4 2016
.AVIATION...
Analysis of evening observations and model data indicate a somewhat
reduced potential for low clouds and fog during the night in the MBS
to FNT region compared to earlier expectations. Westerly flow around
the north flank of the Ohio Valley surface high will continue to
carry increased low level moisture over Lake Michigan and into lower
Michigan, but this air is also warmer from the surface to 900 mb and
less favorable for cloud development. Evening satellite imagery
illustrates the temperature contrast where low clouds remain over
southern Ontario and eastern Lake Erie/Ontario while conditions are
cloud free over the western Great Lakes. It is likely that the
warmer air moving in from the west will take longer to produce
clouds over Lake Michigan and Lower Michigan leading to less
coverage or shorter duration over the SE Michigan terminal corridor.
Those that are able to form will then steadily mix out during the
morning and leave VFR under high clouds by afternoon through
Saturday evening.
FOR DTW... Shallow MVFR fog remains possible for a few hours around
sunrise with an outside chance of brief entry level IFR before the
wind increases slightly. Observational evidence indicates best
potential for stratus staying north of DTW through the morning.
//DTW Threshold Probabilities...
* none.
&&
.PREV DISCUSSION...
Issued at 311 PM EDT Fri Nov 4 2016
DISCUSSION...
A dry and seasonably warm environment will mark conditions through
the upcoming weekend. Moderating thermal profile prompted by a
steady increase in upper heights through this period, the local area
immediately downstream of an elongating upper ridge slowly building
toward the Great Lakes. Deeper column warm air advection ramps up
tonight and Saturday as the flow backs to westerly, allowing for a
steady exit of the residual low level thermal trough. High pressure
anchoring across the Ohio Valley will then introduce a light
southwest low level gradient. 925 mb temperatures by Saturday
afternoon roughly 10 degrees warmer than readings noted today /10-
11C/. This profile will support afternoon highs reaching into the
lower 60s. There is the potential for a fog/very low stratus
component to emerge late tonight, which could subsequently provide
an early day disruption to the diurnal temperature response. Dense
fog formation this past night across WI/IL centered near the
surface high. Downstream advection of this moisture will commence
tonight within backing flow, with higher resolution model guidance
(HRRR, RAP & 4km NAM) displaying very low surface condensation
pressure deficits with saturated near surface conditions per
sounding data by 09z-12z. A high degree of uncertainty here, with
the maintenance of a light SW gradient north of the high perhaps
maintaining just enough mixing to mitigate a larger fog issue.
Will simply provide an introductory patchy fog mention at this
stage.
High pressure eases northward into the region by Sunday as the upper
ridge axis enters the western Great Lakes. Existing air mass
similar to that noted Saturday /maybe a touch warmer/, so highs of
low-mid 60s attainable under a high degree of insolation. More
favorable positioning of the high nearby may provide a greater
opportunity for fog development late Saturday night/Sunday morning.
Surface high pressure and an amplified upper-level ridge will
continue to push east across the eastern half of the U.S., bringing
another round of dry conditions to the region. Temperature highs
will continue to sit steady in the lower 60s as light S/SW winds
advect warmer air into the region. The next chance for precipitation
will come Tuesday night into Wednesday morning as an upper-level
disturbance moves through, however, with weak forcing and dry low-
level conditions, we`re leaving the PoPs low. Otherwise, high
pressure will continue to be the main story for the week, leaving us
relatively dry through the better part of the week.
MARINE...
Northwest winds of 10 to 15 knots will back to the west-southwest
this evening and increase to 20 knots or so over Lake Huron as the
pressure gradient tightens for a short time between high pressure
over the Ohio Valley and a shortwave trough passing just north of
the Great Lakes. Wind gusts will approach 25 knots, especially from
03z-09z. The most persistent gusts will exist where wind funnels up
Saginaw Bay and also through the Straits. Winds will gradually
weaken and become light and variable Sunday as a warmer airmass
works into the area. Light southerly winds will then develop on
Monday as this high settles southeast of the region.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory until 8 AM EDT Saturday FOR LHZ421-441.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....BT
DISCUSSION...MR/AM
MARINE.......DG
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Northern Indiana
731 PM EDT Fri Nov 4 2016
.SYNOPSIS...
Issued at 252 PM EDT Fri Nov 4 2016
High pressure over northern Illinois will move slowly southeast
to the Ohio Valley tonight, and then to the eastern seaboard on
Monday. This will provide fair weather across the area through
early next week. Lows tonight in the upper 30s and lower 40s.
Temperatures will warm a bit over the weekend with highs in 60s
and lows in the 40s expected.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 252 PM EDT Fri Nov 4 2016
Main focus of short term will be potential for stratus/fog
development.
Stratus decks at or below 2000 ft have been slow to erode across
portions of northern Ohio as well as eastern Iowa/NW Illinois/SW
Wisconsin on the periphery of sfc high pressure centered over N
Illinois. The center will drift slowly south through the period with
trajectories of trapped low level moisture seeming to push the
moisture currently NW of the area into portions of Lower Michigan
with Ohio moisture dropping south. HRRR appears to laugh at this
scenario bringing in stratus into NW areas overnight.
Given crossover temperatures will be in the middle to upper 30s in
many locations and forecasted lows will be at least a few degrees
warmer as well as winds around 5 knots suggests fog potential may be
quite limited. Will have a few clouds in the grids but at this point
think mostly clear to clear skies should prevail.
Dry conditions will prevail into Saturday with mostly sunny to sunny
skies and highs reaching into the lower to middle 60s.
&&
.LONG TERM...(Saturday Night through Friday)
Issued at 252 PM EDT Fri Nov 4 2016
Conditions will not feel anything like early November normally
would with all signs still pointing towards above to much above
normal temperatures for the area and limited chances for rainfall.
Upper level ridge will move into the area over the weekend with 582
dm heights edging north by Sunday evening. Mixing will take place
through at least 925 mb and possibly 900 mb yielding afternoon highs
Sat through Monday well into the 60s and possibly a few 70s southern
third or so. Northern stream energy will try to force a front south
into the region Tuesday with ECMWF/GFS varying on handling. Will
continue with dry forecast for the time being.
Ridging will build back in with heights of 579 to 582 in place once
again. Decreasing sun angle will keep full mixing from taking place
with highs in the low to middle 60s. Towards the end of the period,
models show a somewhat more significant trough trying to move into
the Great Lakes with large differences in scenarios (both for
temperature and precip). Will hold dry forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 729 PM EDT Fri Nov 4 2016
Continued VFR conditions through the forecast period. Isolated
ground fog is possible in some of the more sheltered and low lying
areas. Do not expect to have this affect the TAF sites.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...JT/NG
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Lewis
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Area Forecast Discussion
National Weather Service Lubbock TX
927 PM CDT Fri Nov 4 2016
.UPDATE...
Forecast overnight into the day Saturday looks to remain on track.
Low cloud development is underway across the southern South
Plains and Rolling Plains as easterly flow above the surface
increases and advects higher dewpoint air into the region.
Meanwhile water vapor shows a shortwave trough lifting northeast
around the ejecting upper low over eastern AZ. Lift associated
with this wave is creating scattered showers and storms from the
foothills of the Sangre de Cristos to north of El Paso. This
activity is expected to remain west of the Texas state line
overnight. The latest short range models are indicating however
some light QPF across the Rolling Plains and portion of the South
Plains after midnight. Feel this will mostly be realized as areas
of drizzle as deep isentropic ascent occurs in the absence of
instability. Areas of fog will also be more common as higher level clouds
associated with earlier shortwave exit into OK and north TX and
light easterly surface winds advect upper 50 dews into the Rolling
Plains. Very low clouds, fog and drizzle are expected to start the
daylight hours Saturday and be slow to give way to improving
conditions as the afternoon begins. This should limit instability
and keep thunderstorm chances very low.
&&
.PREV DISCUSSION... /issued 631 PM CDT Fri Nov 4 2016/
AVIATION...
Rapidly deteriorating flying conditions expected later this
evening as southeasterly winds above the surface strengthen and
advect higher dewpoint air northwestward into the region. Only
real uncertainty is with onset of stratus so have kept previous
timing around 06Z which is consistent with latest short range
models.
Cloud cover will lower with time as diurnal cooling and moistening takes
place with fairly widespread visibility restrictions by daybreak.
Areas of drizzle brought about by deep isentropic lift will add to
the cause. LIFR conditions forecast at all TAF sites through the
morning with slight improvement in ceilings during the afternoon.
PREV DISCUSSION... /issued 334 PM CDT Fri Nov 4 2016/
SHORT TERM...
Nicely stacked cyclone was creeping ENE across SE Arizona early this
afternoon upstream of an upper ridge axis poised over the middle of
the Lone Star State. A weak trough was attempting to erode this
trough, but so far ascent and low level saturation have been
lackluster with this wave. Worse, visible satellite shows clear
skies already expanding into our western zones in the wake of this
wave and its shield of high clouds. This clearing is likely to be
consumed by thick stratus tonight as widespread upslope/easterly
winds transport richer mixing ratios westward. Model soundings
support this otherwise ideal pattern of widespread stratus and even
saturate the column deep enough for drizzle at times. This drizzle
could quell the dense fog potential, but RAP, HRRR and MOS indicate
otherwise.
Background ascent looks to remain very muted on Saturday over all
but our far western tiers of counties. Lift there will be aided by a
zone of weakening upper diffluence ahead of the cyclone lifting NE
across the Four Corners. Slight uptick in isentropic ascent could
garner some convective showers near the NM state line, but profiles
are looking less and less promising for any thunder with surface and
elevated CAPE largely absent for much of the day. Farther east, the
bases of very low stratus may rise just enough through the day to
allow for some reprieve from drizzle, but max temps continue to
trend lower toward the coolest guidance given minimal insolation.
LONG TERM...
Showers and thunderstorms remain in the forecast late Saturday
into Sunday as a relatively weak trough lags behind the center of
an upper low interacting with the northern jet across the Rockies
and into the northern Plains. As the trough axis shifts east of
our longitude we will see a narrow swath of drier air briefly
fill in from the Texas/New Mexico border east through the South
Plains to the edge of the Caprock. Another closed low splits from
amplifying ridge across Canada and begins to shift due south out
of the central Rockies toward West Texas on Monday. Surface
pressure falls across a cold front pushing south out of the Texas
Panhandle through the South Plains early Tuesday will increase
chances for more widespread light rainfall Tuesday and Wednesday.
Rain chances continue through the end of next week as the upper
low stalls to our west. Not much confidence in details beyond the
middle of next week until we see how the strongly amplified ridge
to our north begins to break down. Overall the model guidance is
in good agreement with the evolution of the low tracking south out
of the Rockies and parking to our west.
After a warm October and beginning of November we we will see
plenty of clouds and precipitation chances to help drop
temperatures below normal values over the next week or so with
Monday near 70 in our brief window of drier air. Otherwise we`ll
see highs in the low to mid 60s and overnight lows gradually
cooling from 50s this weekend into the low 40s by the end of the
week.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
24
Area Forecast Discussion
National Weather Service Norman OK
954 PM CDT Fri Nov 4 2016
.UPDATE...
Updated temperature/dew point/wind forecast.
&&
.DISCUSSION...
Dew points have remained anomalously high across central/southern
Oklahoma and western north Texas, so opted to increase them based
on trends. However, light east to northeast winds should result in
some drier air to slowly advect eastward across parts of central
Oklahoma tonight. Temperatures were also increased based on the
increased moisture/cloud cover.
The HRRR/HRRRX indicates low stratus and/or fog will
continue/expand primarily across western Oklahoma and parts of
western north Texas. A weak QPF signal on the HRRR/RAP/NAM also
suggests some drizzle is possible. Based on the weak
upslope/easterly flow that is coincident with some moisture
advection, this seems reasonable.
Mahale
&&
.PREV DISCUSSION... /issued 625 PM CDT Fri Nov 4 2016/
DISCUSSION...
AVIATION...
Low clouds are expected to redevelop across western Oklahoma and
adjacent parts of Texas tonight. IFR ceilings will form and some
places will have fog as well. Clouds will stay low over western
Oklahoma most of Saturday with light upslope winds.
PREV DISCUSSION... /issued 224 PM CDT Fri Nov 4 2016/
DISCUSSION...
Overcast conditions have prevailed across mainly southern portions
of the area. Winds will gradually veer to southeasterly this evening
and overnight resulting in moisture moving into northwest Oklahoma
which may lead to fog there. Further southwest across southwest
Oklahoma and portions of western north Texas, visibility is already
slightly reduced and stratus is more extensive. Visibility may fall
as we cool tonight but the better chance of fog seems to be further
northwest where cooling initially this evening may a little quicker
(drier boundary layer and only modest cirrus coverage). RAP forecast
soundings suggest enough depth to the saturated layer for some
drizzle, as was observed across potions of the area this morning.
Have highlighted the most likely areas for patchy drizzle later
tonight through the morning based on latest short term model data,
but spatial adjustments may be needed based on trends.
A cut off low will gradually move northeast and accelerate as it
opens this weaken. The time period for maximum forcing for ascent
and moisture advection that will lead to the highest precipitation
probabilities will be late Sunday through early Monday. Have
deemphasized thunder in the public forecast by limited
thunderstorms to slight chance during this period given lack of
instability seen in model forecast soundings.
Starting the beginning of next week and into the middle of next
week, typical uncertainties arise. Deterministic output is similar
in the overall pattern of departing wave to our east and a
south/southwest moving increasingly closed upper low to our west.
The individual GFS ensemble members show a myriad of possibilities
with how this will evolve and consequently where any areas of
noteworthy ascent are positioned. Until confidence increases,
probabilities will be limited to low-mid range chance and spread
across several days. Adjustments to model blends were minimal for
this forecast issuance. Temperatures should be close to normal
through the forecast period.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 55 68 50 69 / 0 0 0 30
Hobart OK 58 65 53 65 / 10 10 10 50
Wichita Falls TX 59 68 53 67 / 10 10 10 60
Gage OK 49 65 50 66 / 0 10 30 50
Ponca City OK 50 70 48 70 / 0 0 0 10
Durant OK 55 71 49 70 / 0 0 10 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
10/09
Area Forecast Discussion
National Weather Service Tucson AZ
835 PM MST Fri Nov 4 2016
.SYNOPSIS...A few showers may occur across the White Mountains
Saturday morning. Otherwise, dry conditions will prevail into early
next week. The next low pressure system may bring some showers to
eastern areas around mid week. Daytime highs will be near or
slightly above seasonal averages, with seasonably cool overnight
low temperatures.
&&
.DISCUSSION...A weakening low pressure system aloft was centered
over northeast AZ this evening. Clear skies prevailed across
southeast AZ at this time, except for some cirriform clouds mostly
near the International border south-to-southeast of Tucson. Temps at
lower elevations valid 8 PM MST had cooled into the mid 50s-mid 60s,
and winds were light wly/nwly at less than 10 mph.
The upper low will continue to fill while drifting toward the Four
Corners region tonight, then will become an open-wave system with
the mid-level trough axis Saturday afternoon extending from western
Colorado southward into far southeast AZ. 05/00Z NAM suggests that
measurable rain may occur mainly across the White Mountains Saturday
morning with precip-free conditions elsewhere.
The official forecast was updated earlier this evening with this
scenario in mind. Thus, dry conditions will prevail the rest of
tonight, and a slight chance of showers exists across the White
Mountains Saturday morning. Otherwise, dry conditions elsewhere
Saturday with the sky condition ranging from clear to partly cloudy.
High temps Saturday will be nearly identical to temps achieved this
afternoon across eastern sections, but will be a few degs warmer
from Tucson westward into western Pima County and south-central
Pinal County.
Please refer to the additional sections for further detail.
&&
.AVIATION...Valid through 06/06Z.
There is a slight chance of -SHRA mainly across the White Mountains
northeast of KSAD Saturday morning. Otherwise, SKC especially west
of KTUS, and a FEW clouds around 8k-12k ft AGL with FEW-SCT clouds
above 20k ft AGL elsewhere into Saturday evening. Surface wind
variable in direction less than 12 kts. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Dry conditions into Monday except for a few showers
across the White Mountains Saturday morning. The next low pressure
system will then bring a slight chance of showers east of Tucson
around the middle of next week. 20-foot winds through Monday will be
terrain driven less than 15 mph, then gusty east winds should occur
by Wednesday due to the influence of the low pressure system.
&&
.PREV DISCUSSION /257 PM MST/...The low has lifted just north of our
area near the central Arizona border with New Mexico. A partial
clearing trend with some cumulus popping up on recirculated boundary
layer moisture. Greenlee county will still be going for a few more
hours, but most of the activity will be north and east of our area.
Patchy fog possible in eastern areas Saturday morning.
The latest HRRR shows diminishing dew point trends, and along with
the partial clearing, a few spots will drop a degree or two lower
tonight. Tonight and Saturday night we will see chilly seasonal
temperatures with coldest isolated eastern valley locations in
Cochise county dropping into the middle to upper 30s.
Daytime highs will climb a few degrees as a shortwave ridge phases
across the area from the west over the weekend, but not far from
seasonal averages for early November. However, the main strength of
the ridge will probably stay west of our area with impulses sagging
back into the front of the ridge and into New Mexico. Some easterly
spill-over from that could bring a few showers to eastern areas the
second half of the new week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Francis/Meyer
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Lincoln IL
234 AM CDT Sat Nov 5 2016
.SHORT TERM...(Today and tonight)
ISSUED AT 232 AM CDT Sat Nov 5 2016
Main concern initially is the extent of fog early this morning. RAP
soundings in Bufkit indicate we could spike down with some locally
dense fog again around sunrise in many locations of central and
southeast Illinois. Hydrolapse plots show increasing moisture with
height in the lowest layer of the air mass, which is one primary
indicator of fog formation. HRRR and RAP visibility forecasts are
focusing fog west of Decatur to Bloomington and south of Peoria to
Canton. Therefore, have expanded fog into a majority of the forecast
area for the first couple of hours of the morning. Not confident
enough to issue a dense fog advisory at this point due to
uncertainty on coverage, but will monitor closely as the night
progresses.
High surface pressure will dominate the remainder of the short term
forecast, with mostly sunny skies today and mostly clear skies
tonight. Light fog will be possible again late Saturday night due to
little change in air mass, and have included patchy fog in many
areas again.
High temperatures today look to climb above normal, with the help of
southerly winds and nearly full sunshine. Guidance numbers were
generally followed with highs expected to reach the upper 60s west
of I-55 and the mid 60s east of I-55. Lows tonight should bottom out
in the lower 40s, based on expected lowest afternoon dewpoints.
&&
.LONG TERM...(Sunday through Friday)
ISSUED AT 232 AM CDT Sat Nov 5 2016
Main theme for next week continues to be with temperatures remaining
well above normal for early November. While the GFS and ECMWF have
some significant differences with the Tuesday wave, both keep the
colder air over Canada. By late in the week, a pattern change starts
to set up, with a slug of colder air dropping into the Great Lakes.
Will watch this for the upcoming forecast cycles as this is largely
beyond the current forecast range, but current indications are that
it would be short lived.
Regarding the wave in question, the latest models are in reasonable
agreement through Monday evening, with the wave extending across the
eastern Dakotas to along the Manitoba/Ontario border. However, the
latest ECMWF breaks off a piece of energy along the southern part of
the wave early Tuesday, and drops it southwest into Texas by
Thursday morning. This is a significant shift from the morning run
and rather suspect at the moment, so went with a blend of the
current GFS and the old ECMWF instead. With the greater lift near
the Great Lakes, have kept PoP`s in the slight chance range for
Tuesday and Tuesday night. The late week short wave passage
currently appears dry.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1110 PM CDT Fri Nov 4 2016
Some patchy fog with MVFR vsbys still possible in the 09z-13z
time frame, otherwise VFR conditions will prevail for the
remainder of the forecast period. High pressure centered over
east central Illinois will drift slowly away from the area
through Saturday. A band of cirrus clouds was tracking east
out of west central Missouri and will push into west central
Illinois by morning, otherwise a mostly clear sky is expected
overnight. Forecast soundings indicate the most favorable
moisture profile in the low levels will be near SPI by dawn
Saturday with the current dew point spreads the lowest in that
area this hour as well.
Not entirely convinced the remainder of our forecast sites won`t
see any shallow ground fog form towards dawn, but the fact that
the low levels of the atmosphere mixed out well this afternoon and
some high level clouds were expected to push into west central
through central Illinois by morning should keep any development
patchy at best and not as dense as what we saw in parts of our
forecast area Friday morning. Light and variable winds tonight
will become southwest at less than 10 kts on Saturday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...Geelhart
AVIATION...Smith
Area Forecast Discussion
National Weather Service Morristown TN
341 AM EDT Sat Nov 5 2016
.SHORT TERM (Today and Tonight)...
A much cooler start to the morning than just 24 hours ago.
A wide range of temperatures at 3 am generally ranging from the
upper 30s to the mid 50s. These values are still above normal for
early November but much cooler than yesterday morning. Expect there
could be a few isolated areas of frost in the cooler portions of SW
VA and NE TN but do not anticipate anything widespread. Current
water vapor imagery and RAP upper air analysis indicates a ridge
across much of the Central U.S. with a trough just off the Atlantic
Coast. PW values remain in the 0.3-0.4 inch range throughout the
short-term forecast with sunny skies expected today. Upper level
heights will continue to increase today as the ridge builds in from
the southeast. With plenty of insolation and continued dry
conditions, went towards the higher side of guidance with highs
today in the upper 60s to low 70s for most valley locations. Ideal
radiational cooling conditions will setup once again tonight with
clear skies, light winds, and high pressure. However, expect lows
will be similar to slightly warmer than this morning with lows in
the mid 30s to upper 40s. Again, any frost tonight should be
isolated and limited to SW VA and NE TN.
.LONG TERM (Sunday through Friday)...
Little change in the weather pattern early in the extended with a
strong ridge of high pressure remaining in control. This will
maintain the dry and unseasonably warm conditions. Highs will
continue to climb into the upper 60s to mid 70s range with relative
humidities lowering to 35 to maybe around 25 percent Sunday through
Tuesday. This will continue to impact the fire danger potential.
Through the rest of the extended... confidence quite low. Current
run of the GFS has quickened the arrival of an approaching weak
cold front...bringing it into the region Tuesday night into
Wednesday. The ECMWF maintains and a slower movement of Thursday
night into Friday. The strength and amount of associated precip
also remains in question. For now... will keep pops on the low
side...generally 20 to 30...and go with the more consistent slower
timing. However...may begin trending faster with the system based
on future model runs.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 74 47 74 45 / 0 0 0 0
Knoxville McGhee Tyson Airport, TN 72 43 71 43 / 0 0 0 0
Oak Ridge, TN 72 43 71 43 / 0 0 0 0
Tri Cities Airport, TN 66 36 68 40 / 0 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
MA/MJB
Area Forecast Discussion
National Weather Service Denver/Boulder CO
950 AM MDT Sat Nov 5 2016
.UPDATE...
Issued at 930 AM MDT Sat Nov 5 2016
Upper low near the four corners with weak mid level qg ascent
over southwest and south central CO. HRRR runs have been
generating some pcpn over Lincoln County late this morning and
aftn as pcpn shifts gradually northward. The pcpn decreases as it
advects northward so will confine the mention of pops to zones
41..46 and 47 for now. Some adjustment to slightly less cloud
cover as well over the northern tier counties this morning...otherwise
the rest of the grids appear to be on track.
&&
.SHORT TERM...(Today and tonight)
Issued at 314 AM MDT Sat Nov 5 2016
An upper level low near the Four Corner will continue to slowly
lift north-northeast today and tonight as it weakens. Mid and
upper level moisture will increase through out the day. This is
expected to bring scattered showers to the mountains, with the
best chance south. For the Front Range and eastern plains, the low
levels look too dry for precipitation today. The airmass will
remain warm with the snow level in the mountains being 10000 to
11000 feet. High temperatures will be cooler today due to the
increased cloud cover but still well above normal for this time of
year.
Scattered mountains showers will continue into the evening and
decrease overnight. Not a lot of moisture makes it into the
northern half of Colorado. Looking at light snow amounts for the
mountains with a few locations seeing up to 2 inches. Low level
moisture will increase over far eastern Colorado. This will likely
lead to low clouds. There is just a slight chance for rain with
this. If any occurs it will be very light.
.LONG TERM...(Sunday through Friday)
Issued at 314 AM MDT Sat Nov 5 2016
An open shortwave trough is progged to make its way across
Colorado on Sunday bringing scattered light rain/snow showers to
parts of the high country and gusty nwly winds to the Front Range
and adjacent high plains. Winds appear to strengthen some through
the day with increasing subsidence displacing downward momentum
aloft on the back side of the trough. Speeds not expected to
reach high wind criteria but we could see speeds in the 30-50 mph
range on the mtn ridges and foothills. By evening...winds should
subside and the high country showers should come to an end with
drying aloft. Clearing skies and light breezes overnight will lead
to another night of chilly temperatures but readings by morning
still warmer than normal for the date.
By Monday...the upper trough moves east as the mean upper ridge
regains its strength over the Great Basin. A powerful Pacific jet
stream crossing the northern Pacific Ocean roughly between 40-60
deg latitude...will continue to buckle and produce large quasi-
stationary mid-latitude troughs off the west coast of North
America according to the models. This will help to re-establish
the upper ridge over the western CONUS consequently steering
moisture bearing maritime storms well to our north and preventing
any major intrusions of arctic air from Canada. However...models
still show a weak cold front advancing down the front side of
this upper ridge and into northeast Colorado on Monday. Could see
a 4-8 deg f cool down as well as some cloud cover with its
passage. Overnight clearing skies and light breezes are expected
to produce sub-freezing temperatures for most areas.
For the remainder of the week...the western upper level ridge
gradually gains strength and shifts east setting the stage for
above average temperatures...low relative humidity...few clouds
and virtually no chance for precipitation for the forecast area.
Temperatures will run anywhere from 5 to 10 degs f above average
for the first part of November.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 930 AM MDT Sat Nov 5 2016
VFR...with mid and high clouds over the region today. Ceilings
are expected to remain at or above 10000 feet through tonight.
There is a chance for low clouds over far eastern Colorado towards
12z Sunday. At this time, they are still expected to stay well
east of the Denver area. Winds are expected to be on the light
side through tonight. A weak Denver Cyclone may form later this
morning and produce a boundary across the Denver area. Sfc winds
west/southwesterly at this time...progged to become east/southeasterly
this aftn.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Cooper
SHORT TERM...Meier
LONG TERM...Baker
AVIATION...Cooper
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
951 AM CDT Sat Nov 5 2016
.MORNING UPDATE... Increased PoPs for the northern third of the
CWA due to the current radar and satellite trends. Latest HRRR
/TTU- WRF indicate shower development in the Austin area through
the middle afternoon as well. Increased to CHC PoPs and modified
QPF to compensate. Uncertain on coverage in the afternoon as
possible outflow may impact the current environment. May increase
PoPs farther if that indeed takes shape.
Also tweaked hourly forecast grids to ob trends.
&&
PREV DISCUSSION... /ISSUED 415 AM CDT Sat Nov 5 2016/
SHORT TERM (Today through Sunday)...
An upper level trough over Texas will pull away taking the showers
and thunderstorms currently over Central Texas with it by midday.
Patchy fog is possible early this morning. Deep moisture with PWs
averaging around 1.5 inches remains over South Central Texas. Even
though dynamics are lacking, weak upward forcing on this moisture
should generate isolated showers through this evening with
thunderstorms possible around peak heating this afternoon. An
upper level low currently near the Four Corners region opens up
and moves across the Southern Rockies tonight into the High Plains
Sunday. Upward forcing, assisted by a favorable upper level jet
quadrant, increases along the Rio Grande late tonight and across
the remainder of South Central Texas on Sunday. Showers and
thunderstorms become more numerous out west late tonight and
areawide on Sunday. PWs will rise a little and combined with the
possibility of training and slow moving cells, locally heavy
rainfall is possible. This may cause minor flooding, especially in
areas that received heavy rains over the last couple of days.
Clouds and rain will keep temperatures close to normal.
LONG TERM (Sunday Night through Friday)...
The upper level trough slowly moves across the Southern Plains
early next week. Continued upward forcing and upper level
diffluence on slightly above normal moisture levels will maintain
scattered to numerous showers and mainly isolated thunderstorms
Sunday Night and Monday with locally heavy rains possible. A piece
of energy dropping down the back side of the trough will carve out
another upper level low over the Southwestern/Plains States and/or
Northwestern Mexico mid to late week. The models show differing
tracks and evolution of this new low. Rain chances will continue
mid to late week, however, they slowly decrease as lower level
moisture decreases due to surface ridging building into South
Central Texas. Temperatures will average near normal.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 74 62 74 63 74 / 30 20 60 70 60
Austin Bergstrom Intl Airport 75 61 75 63 74 / 30 20 60 70 60
New Braunfels Muni Airport 77 63 75 64 75 / 20 20 60 70 60
Burnet Muni Airport 71 60 71 61 71 / 30 20 60 70 50
Del Rio Intl Airport 75 66 75 65 77 / 20 40 60 30 30
Georgetown Muni Airport 72 59 72 62 72 / 30 20 50 70 60
Hondo Muni Airport 79 65 75 64 78 / 20 20 60 50 50
San Marcos Muni Airport 76 62 75 64 74 / 30 20 60 70 60
La Grange - Fayette Regional 77 61 77 65 75 / 30 20 50 70 70
San Antonio Intl Airport 78 65 74 65 76 / 20 20 60 70 60
Stinson Muni Airport 79 65 76 65 78 / 20 20 60 60 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...24
Synoptic/Grids...TB3
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1008 AM CDT Sat Nov 5 2016
.UPDATE...
Other than bringing the forecast into line with observations, the
main aim of this update was to handle precipitation associated
with a passing upper trough in the far northwestern parts of the
area. Much of the earlier high res guidance had brought the
current area of rain to an end right around...now. Clearly that
isn`t the case, so keeping the afternoon rain chances in place,
and even expanding them southeast just a touch in case there is
enough heating on the edge where outflow boundaries may spark new
showers. Closer to the coast, drier northeast flow should keep
things pretty dry. But, the HRRR and RAP have been generating
light showers in this area through the afternoon. With modeled
PWATs in the 1.5-1.7 range, matching the morning CRP and LCH
soundings, I don`t have the nerve to go totally dry just yet, and
will leave just enough PoP to indicate a slight chance.
&&
.PREV DISCUSSION... /ISSUED 624 AM CDT Sat Nov 5 2016/
AVIATION...
The backdoor cold front was beginning to push in from the
northeast. However, an upper level shortwave trough was generating
showers near or at both KCLL and KUTS at 11Z. There were some MVFR
conditions just to the west of KCLL and north of KUTS. Expect that
there is a small chance MVFR or lower conditions could develop at
either site. However, that would be short lived and expect VFR
ceilings for most of the day.
40
PREV DISCUSSION... /ISSUED 406 AM CDT Sat Nov 5 2016/
DISCUSSION...
A weak s/wv over Central TX is spawning some weak showers over
the northwest half of SE TX. The disturbance should continue to
influence the region with showers mainly this morning with the
precip coming to an end this aftn after the s/wv exits the region.
Slightly drier air will work into the region from the NE this
afternoon. Max temps will trend slightly cooler but will remain
above normal over the southern zones and near normal over the
north today. Tranquil weather will dominate tonight.
Some showers will develop near the coast toward morning with some
speed and directional convergence. An upper level low over the
desert SW will will move east on Sunday. Lift will increase over
SE TX and PW values will increase to 1.60 to 1.70 inches. Fcst
soundings look semi-saturated by afternoon and would expect
showers to increase in coverage. Have tapered PoPs highest in the
SW zones and lower to the NE.
The trough nudges ever so slowly to the east Sunday night and
Monday. Fcst soundings look saturated with PW values between 1.70
and 1.90 inches. Jet dynamics still look rather impressive with SE
TX in a 75 kt LFQ and a well defined splitting jet structure.
Would expect widespread precipitation Sunday night into Monday.
The dynamics and subtle negative tilt in the upper trough axis
supports locally heavy rain late Sunday night into Monday. The
ECMWF and GEM keep the rain going on Election Day and with the
upper trough still to the west and an active jet overhead, feel
it`s best to lean toward the more aggressive and wetter ECMWF. The
upper level trough axis remains west of SE TX through the week but
both the GFS and ECMWF develop a sfc low over the northern Gulf
late Tuesday and this feature will drag most of the precip to the
north and east of the area. The upper flow also becomes more
confluent with time imparting subsidence over the region. Drier
and cooler air will filter into the region Wednesday onward.
Seasonal temps and dry weather will prevail for next weekend with
a W-NW upper flow. 43
MARINE...
Not many marine impacts are expected today. Tide levels only reached
2.6 feet last evening and the overall tides were only between one-
half and one foot higher than normal this morning.
Starting on Sunday, the early part of the new week may again see
some marine impacts. Showers and thunderstorms will return on Sunday
and become more likely Sunday night through Monday night.
Northeasterly winds are expected to reach caution levels by Sunday
night. The moderate northeast to east winds will help raise the tide
levels along the coast and may again begin affecting at least the
Bolivar Peninsula during the times of high tide late Sunday night
and Monday. Diminishing impacts are expected by late Tuesday or on
Wednesday.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 74 60 77 62 73 / 30 10 40 60 70
Houston (IAH) 80 63 80 64 75 / 20 10 40 60 70
Galveston (GLS) 78 72 79 68 77 / 20 20 40 60 70
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
Discussion...25
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
411 AM PDT Sat Nov 5 2016
.SYNOPSIS...
Above normal temperatures and dry weather will prevail across
central California this weekend and through the upcoming week.
Otherwise, patchy fog will be possible throughout the San Joaquin
Valley each morning.
&&
.DISCUSSION...High pressure aloft remains in control with clear
skies and light winds prevailing over central California. Fog is
the main concern again this morning but thus far has not formed.
Visibilities in the San Joaquin Valley have generally been in the
1-3 SM range, though Madera and Hanford have both fallen to 3/4
mile. But GOES GEOCAT LIFR probability has increased along and west
of the Hwy 99 corridor from Merced to Hanford in the last half
hour. The HRRR shows vsbys in this area dropping further through
sunrise, but it was showing the same thing yesterday and they did
not. So will continue to monitor the potential for some dense fog
but it does not seem likely at this time.
Water vapor satellite imagery shows an upper trough off the Pac NW
coast with an impressive band of moisture (PWAT ~ 1.5") ahead of
it. Models agree that this moisture will stay to our north as the
trough moves inland tonight, with just a few mid/high clouds for
our area. The trough will increase the onshore surface pressure
gradient today, resulting in windy conditions through and below
the Kern County mountain passes tonight into Sunday. Westerly wind
gusts are not expected to reach advisory levels but 30-40 mph is
likely in some areas, such as around Mojave. Winds will diminish
Sunday night as the gradient relaxes and turns offshore on Monday
with light easterly winds through the week. Dry conditions are
are also expected to prevail throughout the upcoming week as a
positively tilted upper ridge amplifies over the western CONUS.
Conditions will be favorable for fog in the SJ Valley each night.
Temperatures today will be similar to yesterday with some areas up
a degree or two. The trough tonight will knock temps down slightly
on Sunday, but they will rebound under the ridge early next week.
Highs will generally be around 7-10 degrees above climatological
norms, with the exception of Sunday when they briefly lower to
around 5 degrees above normal.
&&
.AVIATION...In the San Joaquin Valley, areas of MVFR visibilities
due to haze for the next 24 hours. However, IFR with local LIFR
visibilities will occur in fog between 12z and 18z Saturday.
VFR conditions can be expected elsewhere over the central
California interior during the next 24 hours.
&&
.AIR QUALITY ISSUES...
On Saturday November 5 2016...Unhealthy for sensitive groups in
Kings County. Fireplace/Wood Stove Burning Status is: No Burning
Unless Registered in Fresno...Kern...Kings...Madera...Merced and
Tulare Counties. Further information is available at Valleyair.org
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is high.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
NONE.
&&
$$
public...DCH
avn/fw...Riley
synopsis...DCH
weather.gov/hanford
Area Forecast Discussion
National Weather Service Lincoln IL
1023 AM CDT Sat Nov 5 2016
.UPDATE...
Issued at 1023 AM CDT Sat Nov 5 2016
See little to change in forecast this morning as high pressure
continues to dominate the region today. High clouds may temper the
MaxT forecast suggested by 12z KILX sounding which is in line with
current package. Still 5-10F above normal for early November.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 232 AM CDT Sat Nov 5 2016
Main concern initially is the extent of fog early this morning. RAP
soundings in Bufkit indicate we could spike down with some locally
dense fog again around sunrise in many locations of central and
southeast Illinois. Hydrolapse plots show increasing moisture with
height in the lowest layer of the air mass, which is one primary
indicator of fog formation. HRRR and RAP visibility forecasts are
focusing fog west of Decatur to Bloomington and south of Peoria to
Canton. Therefore, have expanded fog into a majority of the forecast
area for the first couple of hours of the morning. Not confident
enough to issue a dense fog advisory at this point due to
uncertainty on coverage, but will monitor closely as the night
progresses.
High surface pressure will dominate the remainder of the short term
forecast, with mostly sunny skies today and mostly clear skies
tonight. Light fog will be possible again late Saturday night due to
little change in air mass, and have included patchy fog in many
areas again.
High temperatures today look to climb above normal, with the help of
southerly winds and nearly full sunshine. Guidance numbers were
generally followed with highs expected to reach the upper 60s west
of I-55 and the mid 60s east of I-55. Lows tonight should bottom out
in the lower 40s, based on expected lowest afternoon dewpoints.
.LONG TERM...(Sunday through Friday)
ISSUED AT 232 AM CDT Sat Nov 5 2016
Main theme for next week continues to be with temperatures remaining
well above normal for early November. While the GFS and ECMWF have
some significant differences with the Tuesday wave, both keep the
colder air over Canada. By late in the week, a pattern change starts
to set up, with a slug of colder air dropping into the Great Lakes.
Will watch this for the upcoming forecast cycles as this is largely
beyond the current forecast range, but current indications are that
it would be short lived.
Regarding the wave in question, the latest models are in reasonable
agreement through Monday evening, with the wave extending across the
eastern Dakotas to along the Manitoba/Ontario border. However, the
latest ECMWF breaks off a piece of energy along the southern part of
the wave early Tuesday, and drops it southwest into Texas by
Thursday morning. This is a significant shift from the morning run
and rather suspect at the moment, so went with a blend of the
current GFS and the old ECMWF instead. With the greater lift near
the Great Lakes, have kept PoP`s in the slight chance range for
Tuesday and Tuesday night. The late week short wave passage
currently appears dry.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 624 AM CDT Sat Nov 5 2016
Some patchy fog with MVFR vsbys are still possible in the 12z-
13z time frame, based on dewpoint depressions of 0-2F. Thin cirrus
arriving from the west will limit any dense fog formation, so will
not include any IFR visibility conditions this morning. Otherwise
VFR conditions will prevail for the remainder of the forecast
period. An axis of high pressure extending across Illinois from
east to west will only drift slowly to the E-SE today. Expect
minimal cloud cover through tomorrow, with mainly cirrus clouds
from time to time.
Winds will start out light and variable this morning, then become
southwest in the 7-10kt range by mid to late morning. Winds will
become light southwest by sunset.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barker
SHORT TERM...Shimon
LONG TERM...Geelhart
AVIATION...Shimon
Area Forecast Discussion
National Weather Service Portland Oregon
329 AM PDT Sat Nov 5 2016
.SYNOPSIS...Today will be a wet day for much of the forecast area, as
strong low pressure off the British Columbia coast drags a slow-
moving but very moist cold front across SW Washington and NW Oregon.
Areas east of Interstate 5 will probably have a dry morning, but the
rain will increase quickly after late morning or midday. Rain may be
locally heavy at times, even over the inland valleys, which may
cause some localized urban or small stream flooding issues...
especially where storm drains are clogged. An upper level trough
will finally shove the front east of the Cascades this evening, with
rain tapering to showers. A few showers will linger into Sunday,
then high pressure and offshore flow will bring another round of dry
and mild weather Monday and likely Tuesday.
&&
.SHORT TERM...(Today through Monday)...After a day of record warmth
at some locations across the CWA Friday, big changes are in store
today as a very moist frontal system slowly moves onshore and crosses
Western WA/OR. Heavy rain has already moved onshore in Washington,
where personal weather stations on the Long Beach Peninsula have
already reported around 0.50 to 0.75" of rain just since midnight.
Higher amounts have occurred on the Olympic Peninsula where 2+ inches
have already fallen near Forks. This is a testament to the moisture-
rich air mass along and ahead of the front, where precipitable water
values are up near 1.50". The surface cold front appears to be right
over KLGX radar, evident on the lower elevation velocity and
reflectivity products. Some locally gusty S winds up to 40-50 mph
will be possible along the front for the beaches, headlands, and
exposed areas in the Coast Range. The front is moving eastward/
onshore at a proverbial snail`s pace, likely less than 10 mph.
With precipitable water values at 3-4 standard deviations above
normal for the time of year, strong dynamics, but a slow moving
front, the potential is there for substantial rain totals as this
front slowly crosses the Willamette Valley. S-SW winds on the order
of 35-45 kt at 850 mb will provide good orographic enhancement on
favored slopes. The typical higher amounts will occur along the coast
and Coast Range, where 2-4 inches of rain are possible by the time
rain tapers to showers on the cold side of the front.
However, the real potential for problems may be over the interior
lowlands and urban areas as rain develops later this morning and
intensifies during the afternoon hours. Satellite water vapor imagery
shows a nice batch of convection developing along the front off the
northern CA coast, the debris of which will likely become absorbed by
the front and produce a solid steady rain as the front moves slowly
across the forecast area later today. Weak waves of low pressure
along the front - likely impossible for models to really initialize
well over the ocean - will further hold up the front`s progress as it
tries to get across the Willamette Valley today. Meanwhile, higher
resolution models such as the HRRR and WRF show excellent surface
convergence along the front, while model soundings show a
well-saturated atmosphere from the surface almost all the way up to
the tropopause. Conditional instability and favorable right- entrance
jet position/dynamics will also be in play. A sharp and slightly
negative-tilt upper trough now just north of 40N/140W will finally
shove the front eastward later this afternoon into tonight as it
approaches and pivots E-NE through Oregon.
All of this points to the potential for a 1-3 hour period of very
heavy rain rates in the Willamette Valley near the front this
afternoon, somewhat similar but probably not quite as intense as the
Halloween event in 2015. Some locations could exceed an inch in that
short time period, with some upside potential. Who gets impacted by
this will largely depend on where the front and moisture axis are as
the approaching upper trough enhances synoptic lift. The most likely
area appears to be along or just east of the I-5 Corridor, which
would likely impact portions of the Portland, Salem, and Eugene metro
areas. Areas with poor drainage, clogged storm drains, and/or flashy
small streams may have some minor flooding issues as a result. It is
highly recommended that those who live in urbanized areas take one
more look at their storm drains this morning before rain really
starts to increase. Will likely issue a Special Weather Statement, as
confidence on impacts and whether all these ingredients will come
together over urban areas is not quite high enough to warrant an
Areal Flood Watch yet.
Of important note for media and those following along with their
favorite weather apps is that the main radar for NW Oregon, KRTX on
Dixie Mtn, remains down due to a major mechanical failure. The rain
will not show up as heavy as it should on composite radar imagery, or
possibly not at all the further south one gets from Portland and
Tillamook. The main point of mentioning this is a reminder that what
you see on radar imagery may not accurately reflect the situation
this afternoon. We will monitor closely using all the other tools at
our disposal, such as rain and stream gages, satellite imagery,
weather spotters, and numerous other tools.
The steady/heavy rain will quickly taper off from west to east this
evening as the upper trough moves onshore, pushing the deepest
moisture east of the Cascades. There may be just enough instability
with the upper trough for a couple thunderstorms along the North
Coast, so left those in the forecast. Snow levels may briefly lower
enough to dust Santiam and Willamette passes with a little wet snow
Sunday, but impacts should be minor.
A warm front may spread just enough isentropic lift over the area
Sunday night/early Monday morning for some areas of light rain,
mainly for the NW portion of our CWA. Otherwise, the trend will be
for warmer and drier weather Monday as high pressure builds northward
across the area and puts us back into a similar mild and dry offshore
flow pattern to what we had Thu/Fri. Widespread 60s will be possible
again Mon/Tue, especially if skies remain partly to mostly sunny.
Weagle
.LONG TERM...Strong upper level ridging is expected to build across
the Western CONUS behind Monday morning`s weak warm front. 00z
deterministic models are coming into better agreement on holding off
rain associated with the next frontal system well into Tuesday, which
is somewhat expected considering the strength of the downstream ridge
and the drying offshore flow Mon/early Tue. The past couple days,
most models have been trending toward keeping the Western CONUS ridge
strong through midweek, which would likely make it difficult for the
midweek front to pack much punch rain or wind-wise. Best chances for
rain will be along the North Coast, with lesser chances to the SE Tue
through early Wed. Given this, decided to decrease PoPs a good bit
south and east of the Coast Range Mon/Tue. The upper ridge then
reasserts itself after this system, with another round of mild and
dry offshore flow expected Thursday before upstream jet energy from
the Pacific forces the ridge to lean over with a positive tilt
Friday...possibly enough for the next front to bring a decent chance
for rain by Fri/Sat. Weagle
&&
.AVIATION...Very slow moving cold front offshore will push inland
this am, and will be over the Cascades by late afternoon. Will see
and abrupt lowering of cigs as the rain spreads inland this am,
with VFR transitioning to MVFR over much to the interior after
16z. Generally, MVFR and areas of IFR conditions will remain
along the coast through the day, though may see slow improvement
to VFR towards evening. Expect mtns to become obscured in precip
and clouds most of the day.
KPDX AND APPROACHES...VFR this am, but as rain increases after
16z, expect MVFR cigs to increase soon after. Still thinking that
17Z to 01Z will be generally MVFR conditions, mainly as CIGS but
occasionally with rain. Showers tonight, but think may take bit
longer for CIGS to increase to VFR. Typical with slow moving
fronts to have CIGS slow to respond after frontal passage mainly
due to lingering low level moisture behind the front. rockey.
&&
.MARINE...Getting gusts in the 30 to 35 kt range this am, so
current Gale warning looks on track. With the front moving rather
slowly, now sure if will see Gales completely diminish by 5 am.
Still think that front will be close enough to the coast that
strongest winds will have eased, with gusts 20 to 30 kt likely
for rest of this morning.
Seas running up to 15 to 16 ft this am, but as winds ease, so
will the seas somewhat. But baseline westerly swell of 14 to 15
ft will build later today, with mostly 16 to 18 ft tonight into
Sun am. Higher swell will be over the outer waters.
Another system approaches late Sunday and into Monday will
possible gales again. But seems to be a repeat of what have seen
on Fri, with south to southeasterly winds being the stronger well
offshore. Will trend forecasts in that direction.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Gale Warning until 5 AM today on all coastal waters.
Small Craft Advisory for Rough Columbia River conditions
today through Sunday am.
&&
$$
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. The area is
commonly referred to as the forecast area.
Area Forecast Discussion
National Weather Service Denver/Boulder CO
243 PM MDT Sat Nov 5 2016
.SHORT TERM...(This evening through Sunday)
Issued at 130 PM MDT Sat Nov 5 2016
An upper low located near the Four Corners region this aftn is
progged to move slowly east/northeast through Sunday. For tonight
the flow aloft will continue to be southerly, then the flow aloft
will weaken and become west/northwesterly on Sunday as the trough
moves eastward. Weak mid level qg ascent coupled with some aftn
instability has allowed for sct to nmrs rain and snow showers in
the high country today, especially south of interstate 70. Overall
will maintain sct pops in the mountains overnight. Not much in
the way of accumulating snowfall expected at this time. Across the
northeast plains, isold showers from around denver southward are
progged to weaken as they move northward this aftn and evening.
The latest HRRR runs continue to reflect this trend. Will keep
isold pops in the grids mainly along and south of the interstate
70 corridor. The mdls continue to show low level moisture/stratus
over the eastern plains tonight...and continue to keep it east of
Denver Sunday morning. On Sunday, weak qg ascent will continue
ahead of the upper trough axis with increasing mid level
subsidence fm west to east. Will keep scattered pops in the
mountains through early aftn with isold pops on the far eastern
plains, should see them all decreasing in the afternoon.
.LONG TERM...(Sunday night through Saturday)
Issued at 130 PM MDT Sat Nov 5 2016
The potential for showers will diminish over the high country and
far eastern plains Sunday night as a shortwave ridge moves in,
however following close on its heals a shortwave trough will push
in Monday morning. Due to the limited depth of moisture and
downward QG motion, have kept out any chance of precipitation over
the high country, however there may be a few flurries/sprinkles
Monday morning.
A cold front will push south over the plains Monday for highs to
be about 5 degrees cooler. Some clouds in the morning should give
way to mostly clear skies later in the day.
The rest of the week and into the weekend will feature abnormally warm
and dry weather as the strong upper ridge over the western
states and into the Northern Rockies prevails. A weak cool push is
expected Thursday to surge down the plains for a slight cool down.
Otherwise temperatures will be 10 to 15 degrees warmer than
average for this time of year.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 130 PM MDT Sat Nov 5 2016
VFR conditions expected through the period. Generally southerly
winds this aftn and overnight. Weakening showers moving across
Denver from south to north not expected to impact the terminals as
they pass across the Denver area. Could see brief bkn cigs in the
080-10kft range this aftn, but overall cigs will be much higher.
Mdls continue to show stratus over the plains of northeast and
east central CO tonight into Sunday morning, but this remains well
east of the Denver area.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Cooper
LONG TERM...Kriederman
AVIATION...Cooper
Area Forecast Discussion
National Weather Service Buffalo NY
412 PM EDT Sat Nov 5 2016
.SYNOPSIS...
High pressure ridged from the Ohio Valley to the Upper Great Lakes
will slowly drift eastward to the Atlantic coastline through Tuesday...
while maintaining dry and seasonably mild weather across our region.
A weak cold front will then cross the area Tuesday night along with
some scattered showers...with dry and quiet weather then returning
for Wednesday and Thursday.
&&
.NEAR TERM /THROUGH SUNDAY/...
High pressure will persist across Western New York tonight, providing
another mainly dry night. A weak shortwave is forecast to track
across the North Country tonight, but with limited moisture this
will should bring only an increase in cloud cover this evening,
before drier air moves in later tonight. HRRR and other higher
resolution models show a cloud streak across the eastern end of Lake
Ontario to the Tug Hill Plateau area, but no indication of
precipitation. Even with a northwesterly wind overnight, expect
neutral temperature advection so there will not be substantial
cooling. Low temperatures in many areas will be in the upper 30s to
lower 40s.
High pressure remains across the region on Sunday, with the center
of surface high pressure settling in across the easter Great Lakes
and Western New York. Some thin high clouds may stream across the
region on a north-northwest flow far aloft, but otherwise it will be
a mostly sunny and dry day. High temperatures will climb to the
lower 50s across Western New York west of the Genesee Valley with
mid to upper 40s over Central and Northern New York where
temperatures aloft will be a little cooler.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Monday into Tuesday will be characterized by fairly quiet weather
and a warming trend to above normal temperatures again. By late
Tuesday into Wednesday night a cold front will cross the region,
bring some scattered showers followed by a return more normal high
temperatures Wednesday.
Looking at the details, Sunday night will be quite chilly across the
region. As we get caught between the departing low pressure system
off the New England Coast and the amplified ridge axis building in
across the upper Great Lakes, the surface high will settle over the
area Sunday night. This cool, dry airmass, along with light winds
under the center of the surface high will result in optimal
radiational cooling conditions. Freezing temperatures are likely
across most locations expect for the lake plains locations, which
are more likely to remain just above freezing in the mid 30s. Areas
of frost will likely develop overnight, especially east of Lake
Ontario and across the Southern Tier.
Monday into Tuesday will give a warming trend as the sharp ridge
axis over the upper Great Lakes moves across the region Monday and
across New England by Tuesday. As the surface high tracks off the
Mid-Atlantic coast, so will the shallow cool airmass, bringing a
return to southwesterly warm advection ahead of the next approaching
shortwave to cross region the Tuesday night into Wednesday. Tuesday
looks to be fairly breezy across the region as the wind is
accelerated ahead of the approaching wave and cold front, with gusts
25 to 30 mph across the typical breezy lake plains locations and
Niagara Frontier. There will be a gradient in temperatures across
the region Monday, with low 60s from the Genesee Valley westward,
tapering off to the low 50s across the North Country, which will
remain closer to troughing aloft and cooler temperatures. By
Tuesday, the deepening southwesterly flow across the area will
result in fairly mild temperatures across western and north central
NY. Downslope regions from the Genesee Valley across the northern
Finger Lakes may surge into the low to mid 60s, while most other
locations see highs in the upper 50s to low 60s.
By late Tuesday afternoon into Tuesday evening, a fast moving
shortwave trough will move from the upper Great Lakes to the lower
Great Lakes, breaking down and shunting the upper level ridging off
the East Coast. The wave and associated cold front should pick up
just enough mid-latitude moisture from the central plains to result
in at least scattered showers across the region Tuesday night. On
Wednesday, the synoptic forcing and deep moisture will already be
displaced well to our east into New England. However, the cold
advection in the northwesterly flow behind the wave, along with
shallow synoptic moisture will likely result in some lingering lake
enhanced and orographic enhanced areas of drizzle and low cloud
cover, especially southeast of the lakes. High temperatures on
Wednesday will be near seasonal normals in the low 50s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
The long term forecast is starting to trend toward a pattern more
conducive for unleashing snaps of colder air across the Great Lakes
and northeast from mid-November through probably the end of the
month. The key to this pattern change remains the anomalously strong
ridge now across the central CONUS. Global ensembles agree on
maintaining and redeveloping this strong ridging while retrograding
it slowly westward with time.
By late next week, this ridge is expected to amplify to record high
H25 heights for this time of year (per NAEFS climo) over the inter-
mountain west as far north as the arctic circle in western Canada.
The result for us here in western NY will be the development of
northerly flow from the arctic circle to the Great Lakes, allowing
for an outbreak of cold air across the Great Lakes for the weekend.
GFS and EC ensembles are coming into much better agreement on this
troughing and colder air now, with the operational runs showing 850
mb temperatures of -9 to -10 C over NY State Saturday afternoon.
Have used a consensus of the raw model guidances for temperatures
into the weekend, as much of the MOS and bias corrected guidance
will not perform well at this range and under a significant pattern
change. This could result in high temperatures in the low to mid 30s
on Saturday and in the mid 20s to low 30s for Friday and Saturday
nights.
Temperatures this cold under the upper level trough tracking from
the Hudson Bay to Maine will result in a lake response in the
northwesterly flow. This lake response will be aided by any
shortwaves rotating around the parent trough and synoptic moisture
trapped within the parent trough. Some locations southeast of the
lakes may see some of their first lake effect snow of the season,
though it is much to soon speculate on placement and intensity.
Looking farther ahead, through the end of the month, longer range
models such as the CFS are showing a more persistent pattern of
ridging across western Canada and into Alaska and along the west
coast, which would help keep the door open to colder outbreaks of
air across the Great Lakes and northeast CONUS. The most recent 3 to
4 week outlook from the Climate Prediction Center also highlights
the Great Lakes region for potential below normal temperatures to
end the month of November.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
A weak shortwave will approach this evening which will bring
increasing cloud cover to parts of Central and Northern New York.
There are also indications of lower ceilings across the Southern
Tier, with possible IFR to the east of KJHW. Have included SCT IFR
cloud at KJHW for a period from 03Z to 10Z. Expect VFR conditions
across the rest of the region, and for the entire forecast area
during the day on Sunday.
Outlook...
Sunday night through Tuesday...Mainly VFR.
Tuesday night...MVFR/IFR in showers.
Wednesday and Thursday...MVFR/VFR.
&&
.MARINE...
Winds and waves have fallen to below advisory levels on western
Lake Ontario...allowing for the cancellation of the small craft
advisory for that region. Elsewhere...brisk winds and choppy
conditions will persist across Lake Erie and eastern Lake Ontario
into this evening...for which small craft advisories remain in
place.
Winds and waves will diminish later tonight and Sunday as high
pressure builds across the region, with winds varying from northerly
early Sunday to southerly by Monday morning. Stronger southwest
winds will develop on Tuesday, then a cold front is expected to move
through on Tuesday night with a shift to northwesterly flow.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ040-
041.
Small Craft Advisory until 11 PM EDT this evening for
LOZ044-045.
&&
$$
SYNOPSIS...JJR
NEAR TERM...WCH
SHORT TERM...CHURCH
LONG TERM...CHURCH
AVIATION...WCH
MARINE...JJR/WCH
Forecast discussion for routine afternoon forecast issuance
.SHORT TERM...Tonight and Sunday
Issued at 220 PM CDT Sat Nov 5 2016
The latest RAP analysis and satellite/radar imagery show a massive
high pressure system centered over the Ohio Valley. Besides just
some wispy cirrus, skies are mostly clear across the region, and
also upstream over the northern Mississippi Valley and Dakotas. With
the surface high moving little through the end of the weekend, temps
and prospects for fog are the main forecast concerns.
High pressure through the column will remain across the region
tonight and Sunday. The airmass within this high remains very dry,
so looking at mostly clear and calm conditions over the period.
These conditions will support another night of ground fog late
tonight into early Sunday morning away from the lake. Because winds
in the boundary layer are weaker than last night, think fog has
potential to be more widespread and dense so increased wording in
the forecast.
Not much change to temps over the next 24 hours. Projected 925mb
temps on Sunday look similar to todays, so highs should continue to
top into the middle to upper 60s.
.LONG TERM...Sunday Night Through Saturday
Issued at 220 PM CDT Sat Nov 5 2016
Well above normal temperatures and a few opportunities for light
showers will be the general rule for the upcoming extended period.
A cold front will sweep through the western Great Lakes Monday
night, bringing the chance for light showers late Monday across
the northwest cwa, and through the rest of the area Monday night.
Rain chances will be relatively low given the limited moisture
available to this northern stream system, mainly in the chancy
category.
The push of cold air behind this system will be relatively
unimpressive, with temperatures on Tuesday although they will be
several degrees cooler than Monday, will still be several degrees
above normal for this time of year.
The next system of consequence tracks to the north on Thursday and
brings a cold front through the area during this time period. The
fropa itself will be dry given very limited moisture. However
there will be a chance for some showers across the northern cwa on
Friday behind the front as a mid level shortwave takes advantage
of a favorable fetch for some lake effect moisture to make it into
the column for some rain shower activity. Even with this setup
rain chances will be relatively low given the lack of deep
moisture available to the shortwave.
Some showers are possible in northern Wisconsin on Friday as a
cold front and some mid level short wave energy pass. The front
will bring the coldest daytime highs that the forecast area has
seen for a while. Even so, it will still be warmer than normal
with highs mostly in the 45 to 50 degree range. Temperatures
behind the departing cold front Friday and Saturday will be quite
cool compared to recent temperatures. Despite this cooler weather
temperatures will only cool to around climatological normals for
this time of year.
&&
.AVIATION...for 18Z TAF Issuance
Issued at 1235 PM CDT Sat Nov 5 2016
High pressure will remain in place through the end
of the weekend. Only aviation concern is the potential for fog
development late tonight into early Sunday morning away from Lake
Michigan. Like the last few nights, ground fog may form after 9 or
10z tonight and last through 14z or so, with some places falling
below airport minimums. Any fog that forms will dissipate after 15z
and then more excellent flying weather for Sunday and Sunday evening.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kurimski
AVIATION.......MPC