Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/22/16
Area Forecast Discussion
National Weather Service Albany NY
1049 PM EDT Fri Oct 21 2016
.SYNOPSIS...
A large slow moving storm system will continue to impact the
region through the weekend bringing much needed rainfall to the
area. Mild conditions ahead of the storm will be replaced much
cooler and blustery conditions for the weekend. Some light
accumulations of snow are possible across the higher terrain of
the southern Adirondacks, southern Green Mountains and eastern
Catskills Saturday night into Sunday.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 1049 PM EDT...Frontal boundary appears to be through the
region with winds now switching to the northwest and drier low
level dewpoints starting to advect into the region. Although most
of the evening has been dry, some rain showers on the backside of
the low pressure area are starting to spread across the Mohawk
Valley and Adirondacks. It may take until late tonight for eastern
parts of the area to see the rainfall return, as the rainfall on
the backside of the storm will be slow to move eastward. Most of
the rainfall will be fairly light in intensity, but 3km hrrr
suggests coverage will be increase by the late night hours.
Some patchy fog developed due to the moist low levels and light
winds. However, this fog should start to dissipate as winds
continue to increase in the wake of the front. However, lingering
low level moisture and showers will continue to allow for plenty
of low clouds through the overnight hours. As colder air starts to
work into the region, temps will start to tumble down in the 40s
and 50s.
Expecting temperatures to fall through the night bottoming out
from the upper 30s across the western Adirondacks to the around 50
degrees in the mid Hudson Valley.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
The stacked system will deepening as short waves rotate about the
low. The system will move slowly northward across New England and
into the Canadian Maritimes Sunday/Monday. The low will begin to
fill and weaken on Sunday.
Rain will swing across the area during the day Saturday especially
during the morning. The region will then be under cyclonic flow
as the storm heads northward with wrap around showers occurring.
Additional rainfall amounts of about 3/4 to 1 1/2 inches are
expected tonight through Sunday with the highest totals across the
northwest portion of the forecast area.
Winds on the back side of the deepening system will become brisk
and gusty Saturday night and Sunday. At this time, it appears wind
gusts should fall short of wind advisory criteria (gusts 46+ mph).
The strongest winds will be over the area Saturday night, however
do not expect all the wind will mix to the surface. Mixing will be
better during the day Sunday. Will keep mention in the Hazardous
Weather Outlook.
Temperatures will recover little if any on Saturday from Friday night
lows in cold air advection. Plus the brisk and gusty northwest
winds will only make it feel even colder.
As colder air is ushered Saturday night and temperatures fall the
rain should change to snow across the higher terrain of the
southern Adirondacks and southern Green Mountains with some
snowfall accumulations possible Saturday night.
Conditions will gradually improve Sunday as the storm weakens and
moves farther away. Temperatures will be seasonable and winds
still brisk and gusty.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
An upper level trough will be moving across the Northeast for Monday
night into Tuesday. Temps aloft are rather chilly (850 hpa temps
around -4 to -8 degrees C) and the the cyclonic flow over the
eastern Great Lakes will allow for some lake-enhanced precip to
occur for parts of the western Adirondacks, western Mohawk Valley,
Schoharie County and eastern Catskills. Precip will generally be
light rain showers due to the boundary layer temps being fairly
warm, although there could be some snow showers at times for the
higher elevations during the overnight hours. Little to no snow
accumulation is expected. Outside of this lake enhanced precip,
skies will generally be partly to mostly cloudy, along with breezy
conditions. Lows on Monday night will be in the upper 20s to mid 30s
and highs on Tuesday will only be in the upper 30s to upper 40s.
As the upper level trough departs, brief ridging both at the surface
and aloft will build into the area for the mid-week period. Although
temps aloft will still be cool, it should be dry with some sunshine.
Lows will be in the mid 20s to mid 30s and highs on Wednesday will
only be in the 40s.
By late in the week, another storm system looks to approach from the
Great Lakes for Thursday into Friday. The latest 12z GFS and ECMWF
have somewhat different solutions, so the forecast is rather low
confidence at this time. For now, will go with Thursday may be
starting off dry, but some rain may move in by later in the day
thanks to the warm front. Showers are then expected across much of
the area for Thursday night into Friday as the storm`s cold front
heads towards the area, although this all will ultimately depend on
the exact storm track and timing. Temps will still be cool in the
40s for Thursday, but behind the warm front may warm up into the 50s
ahead of the cold front for Friday.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Mainly dry for now with variable flying conditions, but periods
of IFR/MVFR conditions possible overnight thanks to plenty of
lingering low level moisture in place. Light or calm winds will
become N-NW behind a departing cold front around 03z-06z and
increase to 5-10 kts.
Additional rainfall to return to the region late tonight into
early tomorrow morning (generally beginning 09z to 12z) on the
backside of the departing low pressure area. IFR conditions for
both vsby/cigs is expected with this rainfall, which looks to last
into a good part of the day on Saturday. Rainfall will taper off
from south to north during the afternoon hours, although lingering
showers into the evening will still keep at least MVFR conditions
in place. W-NW winds will increase to 10 to 15 kts by afternoon
with some higher gusts, especially for KALB.
Outlook...
Saturday Night: High Operational Impact. Windy With Gusts To 30.0 Likely SHRA.
Sunday: Moderate Operational Impact. Windy With Gusts To 32.0 NO SIG WX.
Sunday Night: Moderate Operational Impact. Chance of SHRA.
Monday: Low Operational Impact. Breezy NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
A large slow moving storm system will continue to impact the
region through the weekend bringing much needed rainfall to the
area. Mild conditions ahead of the storm will be replaced much
cooler and blustery conditions for the weekend.
&&
.HYDROLOGY...
A large slow moving storm system will continue to impact the
region through the weekend bringing much needed rainfall to the
area. Mild conditions ahead of the storm will be replaced much
cooler and blustery conditions for the weekend.
Rainfall have varied across the region. Areas that did not get
rain last night got some today. The rain is much needed. Additional
rainfall amounts of about 3/4 to 1 1/2 inches are expected tonight
through Sunday with the highest totals across the northwest
portion of the forecast area. As the colder air is ushered in
rain is expected to change to snow across the higher terrain of
the the southern Adirondacks, southern Green Mountains and eastern
Catskills Saturday night into Sunday.
Mainly fair weather is then expected through mid week with
unsettled weather later in 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/Frugis
SHORT TERM...IAA
LONG TERM...Frugis
AVIATION...Frugis
FIRE WEATHER...IAA
HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service State College PA
1125 PM EDT Fri Oct 21 2016
.SYNOPSIS...
A cold front moved southeast through Pennsylvania Friday. Blustery
northwest winds will usher in much colder air overnight and
Saturday. Occassional like showers are possible through Saturday
night especially across the mountain areas and the north. The
first bout of lake effect and upslope rain and snow showers are
possible over some of the higher ridge tops.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Made adjustments for the timing of the colder air which is
alreading sweeping into the lower Susq Valley and minor tweaks to
winds and dew points for the overnight period across the region.
Light showers or drizzle continues mainly over the western and
northern zones associated with the upper level trough with a few
spotty showers elsewhere. This is expected to coninute to diminish
overnight as the trough slowly pushes east.
Flooding abated and the smaller streams are receding with water
moving down the mainstem rivers now. No additional flooding
anticipated.
Something to consider for later tonight into early Saturday will
be the potential for the season`s first accumulating snows over
the RIDGETOPS of the Laurels and Northern Mountains. The guidance
has been persistent in bringing the coldest 850mb temps of the
season to date in behind our deep upper low. The potential for a
light slushy inch over the ridges is shown in the HRRR and NCAR
ensemble. The deterministic NAM and GFS are showing chances for
light accums over larger more general areas of the west and north,
this seems too generous given surface temps will be relatively
warm. Am thinking we will try to emphasize a light slushy accum
over the higher elevations only.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
A cool and unsettled day is in store Saturday as persistent
northwest flow and progressively cooler boundary layer air is
forced into the region. In fact 850 mb temps remain
below 0 throughout the day throughout central PA...and we`ll
certainly be looking at a few wet snowflakes mixing in at times
with some of the showers over the higher terrain of the northwest
and northern mountains. Under scenarios such as what we expect,
the best chance for measurable precipitation usually favors these
western and northern higher terrain areas with little more than
sprinkles elsewhere.
Maxes will range from the lower 40s northwest to the lower to
middle 50s southeast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As the surface and mid level systems track through eastern Quebec,
a broad cyclonic/northwest flow pattern will continue into early
next week. Models forecast lingering deformation or lake-enhanced
pcpn to come to an end by early Sunday morning. Gusty winds will
should weaken a bit with peak gusts not as strong as Saturday.
Focus will shift upstream to a series of shortwaves diving
southeast from the Upper Midwest/Great Lakes through the Northern
Mid Atlantic region. Models show some varying QPF solutions with
these features, but with limited moisture look for max amounts in
the 0.10 to 0.25 range over north-central PA. Following a brief
moderation in sfc- 850mb temps on Sunday, the aforementioned
shortwaves will bring a reinforcing shot of chilly air into the
area with below normal temps forecast into the middle of next
week. High pressure should provide dry weather Tue-Wed with pcpn
probs increasing toward the end of the week, with GFS/EC models
and ensembles showing a low pressure system reaching the Great
Lakes/Ohio Valley by Thursday.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
For the 03Z package, adjusted the timing of the patchy
rain to the west some.
Across the southeast, left VCSH in, given more activity lifting
northward from MD.
Earlier discussion below.
00Z TAFS sent.
Problem will go from low clouds tonight to gusty winds
on Saturday. A few rain showers tonight, may mix with
some snow at JST and BFD by early morning.
Improving conditions for the later part of the weekend.
Visibility overall not expected to be very low over the next
few days, except for brief time periods in heavier rain and
snow showers.
Outlook...
Sun...No sig wx.
Mon...Mainly VFR. MVFR with rain showers possible NW.
Tue-Wed...No Sig Wx.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Watson/La Corte
NEAR TERM...Watson/La Corte
SHORT TERM...La Corte
LONG TERM...Steinbugl
AVIATION...Martin
Area Forecast Discussion
National Weather Service Green Bay WI
1050 PM CDT FRI OCT 21 2016
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Saturday
Issued at 247 PM CDT Fri Oct 21 2016
The latest RAP analysis and satellite/radar imagery show a surface
ridge axis extending from north-central Ontario, across central WI
to central Texas early this afternoon. But despite the close
proximity of the surface high, a cold airmass and steep low level
lapse rates continues to lead to widespread low clouds, similar to
yesterday. Think this cloud cover will persist through the rest of
the afternoon, and likely into much of the evening over eastern WI.
Not out of the question that a spotty shower could occur over
Marinette and Door counties. Looking upstream, broken mid and high
clouds are pushing east over the northern Mississippi Valley in a
region of warm advection. A few weak returns are showing up over
eastern North Dakota and northern Minnesota. Forecast concerns
revolve around light precip chances and cloud trends.
Tonight...High pressure at the surface will be moving across the
region tonight. The high is not exactly clean however, so will keep
scattered wording over north-central WI into the evening. Otherwise,
think the broken cloud cover will persist over eastern WI through
much of the evening and possibly overnight over the Door. Deep upper
troughing will finally depart the area overnight, and the resultant
warm advection will bring a swath of broken mid and high clouds
across the area. The saturated layer is not really deep, so at best
think only a few sprinkles will be possible. Confidence is too low
for an inclusion of sprinkles into the forecast though, and will
leave the area dry instead. Lows mainly ranging from the mid 20s to
mid 30s.
Saturday...A layer of 5-6 kft clouds will shift east across the
region through the morning and into early afternoon with warm
advection lowering. The atmosphere becomes really dry above this
layer, so precip chances will be too small to mention. As the
clouds depart in the afternoon, should see the sun return along
with warmer temps. Highs in the mid to upper 50s.
.LONG TERM...Saturday Night Through Friday
Issued at 247 PM CDT Fri Oct 21 2016
Northwest flow will prevail into early next week, with generally
dry quiet weather expected. The main exception will be Sunday when
a mid level disturbance tracking through the northern Great Lakes
brings the chance for showers across the extreme northern cwa. The
next significant chance for widespread rain arrives during the
middle of next week as a low pressure system develops across the
central plains on Tuesday. This low will track to the south of the
area on Wednesday and Wednesday night, bringing rain to much of
the area. Being on the cold side of the system there could be a
few snowflakes mixed in with the rain at times Monday night and
Tuesday night across north-central Wisconsin, however the impact
is expected to be minimal. Although the low will be east of the
area late next week, additional shortwaves embedded in northwest
flow will bring a small chance for showers during this period.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1050 PM CDT Fri Oct 21 2016
As high pressure drifts slowly east overnight, a weak
frontal system will move into the western Great Lakes region.
A period of mainly vfr clouds will pass over tonight into
Saturday morning.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kurimski
AVIATION.......TDH
Area Forecast Discussion
National Weather Service Gray ME
1010 PM EDT Fri Oct 21 2016
.SYNOPSIS...
A slow moving frontal boundary and a developing low pressure
center will bring wet weather and a cool onshore flow to the
region into Saturday. Later Saturday and Saturday night...the low
will gradually lift north into Quebec. On the backside of this
system...colder air will arrive on gusty northwest winds for the
latter part of the weekend and early next week. Some accumulating
snow will be possible in the mountains Saturday night into Sunday
night. A large Canadian high pressure system will then dominate
the region through midweek next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
10PM UPDATE...Narrow band of intense convective rainfall formed
along a developing trough as it moved across southern New England
this evening. This intense rainfall led to flash flooding in
several locations along its path, extending up into southern New
Hampshire. As this rain has made its way north, it has fanned out
into a broader area of heavy rainfall which is now impacting most
of western Maine as the primary line has moved into the seacoast
of New Hampshire. We have made significant updates to
precipitation chances and total rainfall amounts based on how we
expect this event to unfold going forward. Flood Advisories have
been issued for much of western Maine and Flash Flood Warnings
will be issued for any areas which see prolonged heavier rainfall.
Much of western Maine has already had an inch or more of rain
which has caused street flooding in spots, so additional rainfall
could cause more significant issues.
530pm update... Main update at this time was to the PoP to more
closely reflect the radar returns showing rain pushing into
western new hampshire and keeping eastern sections lower.
Region of stronger convection /as seen by -60C IR cloud tops/ now
moving over the 70W/40N benchmark. Satellite trends and high res
guidance continues to point to it moving northwards into our area
around midnight. Heaviest rainfall would be from portland
eastwards to penobscot bay. While the rain looks to move through
relatively quickly, there is a slight chance for it to get hung
up along the coast which will need to be monitored.
Previous Discussion:
There are two main wx concerns for tonight...rnfl and fog.
For starters marine fog is already creeping back SWwd along the ME
coastline. Inland vsbys have improved slightly...but will trend
back down after dark and likely stay that way as low pressure
moves overhead. NARRE-TL hints at dense fog moving towards the
forecast area from the S after midnight...so at this point will
keep fog in the forecast and monitor for a potential dense fog
advisory.
Regarding the rnfl...the area to watch is developing S of Cape Cod
at this hour. A large area of convection continues to peel off of
the sub-tropical low pressure off the Carolinas...heading towards
New England. The low level moisture has already arrive across Srn
New England...with showers moving N thru the area. I have
increased PoP across Srn NH in the next couple of hours for these
showers. Satellite cloud patterns already suggest low pressure
circulation is developing within this convection...and model
guidance pivots this into Wrn ME this evening. Global guidance of
the GFS and ECMWF have finally come around to the idea of
potentially heavy rnfl along and E of the low pressure track. This
matches hi-res guidance like the HRRR and NCAR ensembles. Most
favorable area will be the border of NH and ME...and on Ewd thru
the night. Best period for potential heavy rnfl will be 00z to 06z
this evening...as the low level jet pivots NEwd.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Band of rnfl exits the forecast area early Sat...but with surface
trough overhead I do not expect much clearing. Stratus should
linger...and there may be drizzle in the early part of the day
with weak lift continuing in the dry slot.
Upper trof swings thru the region in the afternoon. An area of
showers is likely to be forced out ahead of this
feature...sweeping SW to NE across the forecast area in the
afternoon. It is near and after this time that winds will begin to
increase...especially as colder air filters into the area. Behind
the upper trof strong pressure rises may help to bring some gusty
winds...though that potential looks best across Srn New England.
As cold air deepens Sat night it is more likely that is when winds
begin to pick up across our forecast area. At this time it looks
to be a slow and gradual build up...before CAA really kicks in on
Sun. Snow levels will also be dropping Sat night...and some
accumulations are possible at the highest elevations late Sat. The
best shot is above 3000 feet...but elevations down to around 2000
feet may see some flakes as well. Winds and poor trajectory for
cold air delivery most likely keep the valleys well mixed enough
to preclude any snwfl.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Upcoming Potential Hazard: Strong, gusty winds on Sunday.
Winds align through a deep layer as a strong surface low (~980 mb)
exits into the Canadian Maritimes. The upper low shifts east of
New England as well, allowing for a deep, well mixed layer. Models
have shifted into agreement for the passage of the upper level
features. This passage, in combination with a strong gradient and
cold air advection will allow for very gusty winds Sunday. Wind
advisories may be needed as we continue to monitor the situation.
Wind gust over 45 mph would lead to scattered power outages.
Expect upslope rain showers to develop. Cold air advection and the
wet bulb affect will allow the rain showers to mix with and
change to snow showers at the higher elevations where a light
coating of snow is expected.
A short wave quickly races through the region Sunday evening,
bringing a reinforcing shot of cold air and continued very gusty
conditions along with moisture to the region.
The upper level low will remain over the Canadian Maritimes for
much of this upcoming work week. This will keep cool and breezy
conditions over the region as high pressure remains in control of
the Northeast.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Widespread LIFR conditions will continue thru
tonight. Some brief improvement to VFR and MVFR over parts of NH
will deteriorate again tonight as well. The low level jet lifting
over the region late this afternoon and evening will also yield
some marginal LLWS at the TAF sites. LIFR and IFR remains
widespread until late Sat when CAA will start to mix out the
wedged in low level air mass.
Long Term...Conditions will improve to VFR by Sunday morning
outside of the mountains, which will linger in MVFR to IFR briefly
in SHRA at KHIE through Sunday. Also look for NW winds of above
30+ kts on Sunday. VFR is expected at all terminals much of next
week.
&&
.MARINE...
Short Term...SCA conditions will continue into Sat...with brief
breaks in wind as low pressure center moves overhead. Eventually
CAA developing on the backside will increase winds to near gale
force on the outer waters late Sat.
Long Term...A period of gales is possible Sat night into Sunday
with winds diminishing a bit Sunday night into Monday morning.
Gale watches have been issued for the outer waters with borderline
gale conditions possible over the bays.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 PM EDT Saturday for ANZ150>154.
Gale Watch from Saturday evening through Sunday afternoon for
ANZ150-152-154.
&&
$$
NEAR TERM UPDATE... Kimble
Area Forecast Discussion
National Weather Service Northern Indiana
759 PM EDT Fri Oct 21 2016
.SYNOPSIS...
Issued at 7:57 PM EDT Fri Oct 21 2016
Lake effect clouds and scattered rain showers will persist
downwind of Lake Michigan into a portion of the overnight hours.
Most lake effect showers will begin to retreat back towards the
lake through the overnight. Outside of any cloud cover,
temperatures will fall into the 30s for overnight lows with some
patchy frost possible. Locations that remain in the clouds will
see lows in the upper 30s to around 40. Clouds will slowly break
up during the day Saturday with highs in the 50s.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 240 PM EDT Fri Oct 21 2016
Deformation zone from low pressure moving into the NE states has
finally shifted well east of the area. North to northwest flow
over Lake Michigan has allowed lake effect clouds and scattered
rain showers to develop and now shift into SW Lower Michigan and
NW Indiana. HRRR has a decent handle on uptick in coverage and
intensity of diurnally driven pockets of brief moderate rainfall.
A few showers were even making a run at NE sections courtesy NE
flow off Lk Huron/Saginaw Bay. Lake Michigan activity will persist
into the late evening and even overnight hours but should lose
some of its coverage and intensity as inversion heights begin to
lower and diurnal impacts are felt. going no more than mid to high
chc pops to cover the main band.
On Saturday deeper moisture will begin to wane with inversion
heights continuing to lower, resulting in decreasing clouds and
lake effect impacts. Highs will be on the cooler side with
temperatures ranging from the lower 50s NE near the core of the
coldest air to the upper 50s in the SW.
&&
.LONG TERM...(Saturday Night through Friday)
Issued at 240 PM EDT Fri Oct 21 2016
Generally quiet period through mid week for the area with only
sensible weather issue being weak disturbance dropping through the
northern lakes that may bring a increase in cloud cover north of
US 6. Otherwise, main system will be mid to lake week as trough
rapidly develops across the western Great Lakes and deepens with
shower (thunderstorm?) chances increasing Weds afternoon into
Weds night. Generally went with Superblend of pops through the
period with lingering precip even into Thursday and Thursday
night as trough become negatively tilted. Temperatures will warm
towards more seasonable readings late in the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 755 PM EDT Fri Oct 21 2016
Upper level low slowly moves east with some warming of the lower
levels taking shape around morning. Expecting lake effect showers
to slowly retreat back towards the lake as winds diminish and
delta t moderates. However some showers are expected to linger
around South Bend into a portion of the night. While a few cells
have lowered CIGS and VISBYS nearby South Bend, expecting CIGS and
VISBYS to mostly remain VFR. VFR conditions also expected outside
of lake effect showers.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Small Craft Advisory until 5 AM EDT Saturday for LMZ043-046.
&&
$$
SYNOPSIS...Roller
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Roller
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Area Forecast Discussion
National Weather Service Paducah KY
830 PM CDT Fri Oct 21 2016
.UPDATE...
Issued at 830 PM CDT Fri Oct 21 2016
Latest observations and mesoscale temp guidance indicate the current
forecast is on track. Patchy frost is still expected in the normally
colder low-lying areas outside of urban centers. Latest RAP model
places the surface ridge axis almost directly over the mid
Mississippi Valley at 12z. Conditions should be nearly ideal for
radiational cooling late tonight, aside from some high cloudiness
mainly east of the Mississippi River. Dew points at 01z were right
around 40 degrees, and they had risen since the late afternoon
hours. Overall, the current forecast of upper 30s looks very good,
and any frost should be too patchy to warrant an advisory.
&&
.SHORT TERM...(Tonight through Sunday night)
Issued at 223 PM CDT Fri Oct 21 2016
Surface pressure gradient relaxes across Southeast Missouri during
the evening and over Southern Illinois and Purchase Area of West
Kentucky, eastward to the Land Between the Lakes after midnight
tonight. Between 09z-12z, the WFO PAH CWA will be in the most
optimal range for stable boundary layer stratification, wind
decoupling, etc. Frost development is expected, but the intensity
of the frost is questionable given antecedent insolation,
evaporation, coverage of surface dewpoint depressions less than
0.5F.
If temperatures in the forecast area were to be well into the middle
30s for 2-4 hours, may have revisited an advisory, but at this time,
do not expect this to be an issue, with the possible exception of
county areas north of Interstate 64. Current Special Weather
Statement in effect addresses the specifics of frost development in
the WFO PAH forecast area tonight.
Otherwise, a gradually eastward shift in the surface high pressure
ridge on Saturday into Sunday, as the westerly tilted upper level
ridge broadens during the same time period. An increase in
thicknesses and a return to a more southerly wind component should
mitigate any return to temperatures Saturday night or Sunday night.
Dry and near seasonable temperatures will be the rule through the
short term forecast period.
.LONG TERM...(Monday through Friday)
Issued at 223 PM CDT Fri Oct 21 2016
Confidence in the extended portion of the forecast is moderate.
We will start out with a fairly amplified trough/ridge/trough pattern
aloft. The ridge will be centered over the Plains states with
troughs off the west coast and over New England. As a portion of the
east Pacific trough shears out and tops the ridge, the ridge will
effectively retrograde and become centered over the southern Rockies
and southwest. This will allow the disturbance to amplify as it
reaches our region Wednesday.
The 12Z models continue to show quite a variety of solutions for
this amplification, with the ECMWF and GFS showing a closed low over
Wisconsin with a split flow scenario. Unfortunately, they are about
12 hours apart in doing so. The CMC really digs a portion of this
energy into the southern Plains Wednesday and has a much weaker
trough moving east through the Lakes into the Ohio Valley Wednesday
night.
Prefer the CMC, where we may be stuck between the forcing with the
northern portion of the system, and the moisture being gobbled up by
the southern Plains/Arklatex system. Even if the GFS/ECMWF are
correct, moisture return ahead of it will be very meager in our
region, and figure it will be a light QPF event. The forecast has
trended a bit drier, but will maintain a mention of thunder, as the
models at least have a little bit of elevated instability, and even
surface-based instability at times.
The GFS is still trying to bring another upper-level storm system
and cold front into the region Friday afternoon and night. The ECMWF
is now dry, so there is quite a bit of disagreement here, too. Will
leave a slight chance in the northwest for Friday in case the GFS is
on to something. There will be enough elevated instability if the
GFS scenario is correct to support TS in the forecast.
Temperatures will generally remain at or above normal through the
week.
&&
.AVIATION...
Issued at 620 PM CDT Fri Oct 21 2016
High pressure over the region should provide VFR conditions for
all TAF sites through the period. Northwest winds AOB 5-6 knots
early will go calm overnight, then pick up out of the southwest
to west after 15Z AOB 5 knots.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...MY
SHORT TERM...Smith
LONG TERM...DRS
AVIATION...JP
Area Forecast Discussion
National Weather Service Goodland KS
225 AM MDT Sat Oct 22 2016
.SHORT TERM...(Today through Monday night)
Issued at 225 AM MDT Sat Oct 22 2016
Early morning WV imagery and RAP upper level analysis showing
broad ridging across the souther plains and zonal flow across
the northern plains along the northern apex of the ridge. At the
surface lee trough is in place near the front range with southerly
gradient in place over our CWA.
Today-Monday night: A very deep dry air mass remains in place
precluding any precip chances. Above normal temperatures will
prevail through these periods along with dry conditions. A weak
front will move through the region tonight. Highs today with
good WAA will be in the low 80s across our CWA. A weak cold front
tonight will bring slightly "cooler" temps Sunday and Monday in
the 70s (still 10F above normal).
A shortwave trough along the western extent of the H5 ridge moves
toward the Central Rockies by Monday night and return flow from
the southeast will allow for an increase in BL moisture/surface
Tds. This could result in fog development, and NAM/SREF are
already showing this potential late Monday night/early Tuesday
morning. I held off on introducing this to the forecast for now as
increasing mixing due to BL winds could result in mainly stratus.
If fog signal remains in place we can add as we get closer/more
confident.
.LONG TERM...(Tuesday through Friday)
Issued at 225 AM MDT Sat Oct 22 2016
The axis of a ridge will be in place just east of the CWA on
Tuesday with southwest flow at the surface and aloft. H5
shortwave will push into the area as we head into the afternoon
with dry air in place across the vast majority of the CWA with
slightly better moisture in the far eastern counties. There could
be a few thunderstorms in the easternmost counties with most of
the activity remaining well east of the region. Flow will shift
northwesterly as the shortwave passes to the east with more dry
air being advected into the area.
Northwest flow once more becomes southwesterly as we head into
Thursday with a ridge building into central and western Texas.
Several weak shortwaves will rapidly move across the CWA along the
northwest periphery of the ridge with no PoPs expected with the
passage of these disturbances. As we head into Friday and Saturday,
a deep trough and area of low pressure will move northeastward out
of the southwestern States. The GFS weakens this feature rapidly
as we head into Saturday; however, there is a bit of
disagreement with regards to the timing and strength of the low.
Temperatures during the extended period will remain above average
with highs in the 70s and lows generally in the 40s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1044 PM MDT Fri Oct 21 2016
VFR expected at both KGLD and KMCK through the TAF period. Surface
winds will be light and variable overnight but increase a bit
Saturday afternoon from the south as a lee trough develops in
eastern Colorado.
&&
.FIRE WEATHER...
Issued at 225 AM MDT Sat Oct 22 2016
A warm and dry air mass in place will result in RH values dropping
to near 15 percent or lower across the western half of our CWA this
afternoon. At the same time a LLJ maximum will translate from our
central CWA around midday eastward through the afternoon.
With increasing daytime mixing there will be a brief period of winds
around 25 mph from midday through the early afternoon that could
last 1-2hr.
Lower RH values will tend to correlate with areas where winds are
much lighter in the west, or will trend eastward as the winds are
trending below critical fire weather criteria in our central CWA.
At this point only 1 hr of possible critical fire weather
conditions may occur between highways 25 and 27 in the early
afternoon. Due to the lack of confidence in 3hr crossover of
RH/wind I will not be issuing RFW, but will keep near critical
fire weather mention in HWO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...024
FIRE WEATHER...DR
Area Forecast Discussion
National Weather Service Goodland KS
527 AM MDT Sat Oct 22 2016
.SHORT TERM...(Today through Monday night)
Issued at 225 AM MDT Sat Oct 22 2016
Early morning WV imagery and RAP upper level analysis showing
broad ridging across the souther plains and zonal flow across
the northern plains along the northern apex of the ridge. At the
surface lee trough is in place near the front range with southerly
gradient in place over our CWA.
Today-Monday night: A very deep dry air mass remains in place
precluding any precip chances. Above normal temperatures will
prevail through these periods along with dry conditions. A weak
front will move through the region tonight. Highs today with
good WAA will be in the low 80s across our CWA. A weak cold front
tonight will bring slightly "cooler" temps Sunday and Monday in
the 70s (still 10F above normal).
A shortwave trough along the western extent of the H5 ridge moves
toward the Central Rockies by Monday night and return flow from
the southeast will allow for an increase in BL moisture/surface
Tds. This could result in fog development, and NAM/SREF are
already showing this potential late Monday night/early Tuesday
morning. I held off on introducing this to the forecast for now as
increasing mixing due to BL winds could result in mainly stratus.
If fog signal remains in place we can add as we get closer/more
confident.
.LONG TERM...(Tuesday through Friday)
Issued at 225 AM MDT Sat Oct 22 2016
The axis of a ridge will be in place just east of the CWA on
Tuesday with southwest flow at the surface and aloft. H5
shortwave will push into the area as we head into the afternoon
with dry air in place across the vast majority of the CWA with
slightly better moisture in the far eastern counties. There could
be a few thunderstorms in the easternmost counties with most of
the activity remaining well east of the region. Flow will shift
northwesterly as the shortwave passes to the east with more dry
air being advected into the area.
Northwest flow once more becomes southwesterly as we head into
Thursday with a ridge building into central and western Texas.
Several weak shortwaves will rapidly move across the CWA along the
northwest periphery of the ridge with no PoPs expected with the
passage of these disturbances. As we head into Friday and Saturday,
a deep trough and area of low pressure will move northeastward out
of the southwestern States. The GFS weakens this feature rapidly
as we head into Saturday; however, there is a bit of
disagreement with regards to the timing and strength of the low.
Temperatures during the extended period will remain above average
with highs in the 70s and lows generally in the 40s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 526 AM MDT Sat Oct 22 2016
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. SOUTHERLY WINDS WILL INCREASE MIDDAY TODAY WITH
STRONGEST GUSTS AT KGLD 20-25 KT. WINDS WILL DECREASE AT KGLD BY
MID AFTERNOON AS SURFACE GRADIENT WEAKENS OVER NORTHWEST KANSAS
FROM THE WEST TO THE EAST. LIGHT AND VARIABLE WINDS ARE EXPECTED
AT BOTH TERMINALS BY SUNSET.
&&
.FIRE WEATHER...
Issued at 225 AM MDT Sat Oct 22 2016
A warm and dry air mass in place will result in RH values dropping
to near 15 percent or lower across the western half of our CWA this
afternoon. At the same time a LLJ maximum will translate from our
central CWA around midday eastward through the afternoon.
With increasing daytime mixing there will be a brief period of winds
around 25 mph from midday through the early afternoon that could
last 1-2hr.
Lower RH values will tend to correlate with areas where winds are
much lighter in the west, or will trend eastward as the winds are
trending below critical fire weather criteria in our central CWA.
At this point only 1 hr of possible critical fire weather
conditions may occur between highways 25 and 27 in the early
afternoon. Due to the lack of confidence in 3hr crossover of
RH/wind I will not be issuing RFW, but will keep near critical
fire weather mention in HWO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...DR
FIRE WEATHER...DR
Area Forecast Discussion
National Weather Service Spokane WA
517 AM PDT Sat Oct 22 2016
.SYNOPSIS...
Drier weather will develop today across most of the Inland
Northwest after a weak upper level disturbance tracks through the
Idaho Panhandle this morning. The drier weather is expected to
persist through the weekend for most locations, but the next
weather system is expected to push a threat of rain into the
Cascades late tonight and Sunday. Meanwhile dry weather will
likely persist over most of the area until late Monday or
Tuesday. Wet and unsettled weather will then continue through most
of the week.
&&
.DISCUSSION...
Today through Sunday...2 distinct systems will impact the
Inland NW today. The first is the remnants of the atmospheric
river which moved into the area 2 days ago. According to the
blended precipitable water tool it was still entrenched over
extreme SE Washington and extended into the central Idaho
Panhandle. Decent isentropic ascent was continuing to produce
light to moderate precipitation along this boundary, but it won`t
likely do that for much longer. The reason is a more progressive
trough axis was plowing rapidly eastward through the eastern third
of Washington and will soon move into Idaho. This feature also was
producing some precipitation along a line from Davenport to
Colville, but it was relatively light and fast moving.
Extrapolation of this trough places it into western Montana before
mid-morning. We should see a drier weather picture develop once
this trough moves through the forecast area with little threat of
precipitation for the remainder of the day. The difficult part of
the forecast will then deal with what will happen to the stratus
entrenched over much of the region. Will it burn off or persist
through most of the day? Unlike yesterday at this time there is
quite a bit more stratus than fog and that trend should likely
continue with a gradual drying trend expected in the boundary
layer with a little bit stronger winds.
By late this afternoon and tonight the relatively dry weather will
continue as the low-level winds turn more east to northeast with
the next low pressure area approaching the coast. According to the
NAM model this will take most of the low-level moisture and pile
it toward the Cascades. The dewpoints are also expected to fall
quite a bit given this offshore flow. This suggests fog (if any
forms) will be much less prevalent that what we`ve been seeing
lately. The exception could be over the protected valleys of
northeast and north-central Washington. While most locations will
be dry, the one exception will develop near the Cascades as the
low level moisture piling will coincide with deepening mid-level
moisture associated with the offshore low. This will result in an
increasing threat of light precipitation, mainly west of a
Wenatchee to Omak line. This threat will continue through Sunday.
Any precipitation which forms should be much lighter than what we
have seen lately as there are no signs of an atmospheric river
intrusion. fx
Sunday night through Wednesday night....A prolonged interval of
general warm southerly flow marks most, if not all of this time
interval. Numerous weather systems with fairly well maintained
moisture taps extending toward the south/southwest move through the
forecast area and allow the general trend of forecast temperatures
to remain generally on the warm side of normal with any snow still
confined to the higher mountains. Per the most recent GFS run the
most significant weather features of note to pass include an
occluded front sweeping through Monday night with a slow exit
Tuesday followed by a warm front Wednesday morning which is followed
by another occluded front that moves in and stalls out over the
forecast area Wednesday and on through Wednesday night. /Pelatti
Thursday through Saturday...Multiple features of interest at
the start of this period with a closed low in the Gulf of Alaska
and then either an open wave or closed low along the California
coast shown by the GFS/GFS ensemble and ECMWF respectively.
Models diverge even further after that with how they handle
pieces of energy being spun around the main Gulf of Alaska low
and a new low digging off the CA/OR coast. In any event, it looks
like the rainy pattern will continue with some breaks in the
precip thrown in, although it`s too early to get into the
specifics of when that may occur. Thus at least slight chances of
rain were included throughout the entire extended forecast. With
no major influx of cold air evident, temperatures will likely not
deviate much from what we have been seeing with 50s being fairly
common for highs. /Kalin
&&
.AVIATION...
12Z TAFS: Once again most of the forecast sites will be influenced
by a broad blanket of low clouds covering much of NE WA and N ID.
Winds have picked up quite a bit over extreme E WA behind a passing
upper level disturbance. While this should greatly lower the threat
for dense fog and LIFR conditions, the SW direction will still
likely lead to MVFR cigs and even some IFR conditions (mainly at GEG
and PUW). Confidence is good that conditions will improve to VFR by
midday. The most difficult forecast this morning is for MWH. Dense
fog and LIFR conditions reformed over the past hour and it appears
to be expanding per satellite. The HRRR model depicts this fog and
its been consistently suggesting it will be gone by 18-20z as the
inversion is shallow. After the fog is gone the odds of it reforming
tonight are much smaller than they have been over the past few
nights. This is due to a transition to drier E-NE winds in the lower
atmosphere. While the NE winds should deter fog, it could deepen
moisture at EAT late tonight while an upper level disturbance
approaches the Cascades. This will result in an increasing chance of
precipitation near the Cascade. Not confident this will impact EAT,
but at a minimum there should be lowered cigs with a small chance
of MVFR conditions. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 39 54 45 58 45 / 10 0 10 10 20 60
Coeur d`Alene 52 40 56 44 58 45 / 20 0 10 20 20 60
Pullman 54 43 57 46 62 46 / 0 0 10 10 10 60
Lewiston 59 45 61 48 65 49 / 0 0 10 10 10 40
Colville 53 36 54 41 56 44 / 20 0 10 30 30 80
Sandpoint 50 36 52 40 55 42 / 40 0 10 20 20 60
Kellogg 49 39 56 42 57 42 / 30 0 10 10 20 50
Moses Lake 57 41 59 43 58 43 / 0 0 10 20 20 60
Wenatchee 57 43 55 43 55 42 / 0 10 10 20 40 70
Omak 55 40 55 42 55 44 / 0 10 10 30 40 80
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php
Area Forecast Discussion
National Weather Service Bismarck ND
340 PM CDT Sat Oct 22 2016
.SHORT TERM...(This evening through Sunday)
Issued at 315 PM CDT Sat Oct 22 2016
A low pressure system continues to push west to east across the
northern plains. Short range models have handled the precipitation
well. Rain for the most part has stayed in the northern tier
counties of North Dakota. Chances for rain will diminish as the
system pushes further east tonight.
The previous few HRRR runs have shown the potential for some fog
to develop overnight in the northwest. However with minimal low
level moisture and the potential for cloud cover in the area have
held off on the mention of fog at this time.
.LONG TERM...(Sunday night through Saturday)
Issued at 315 PM CDT Sat Oct 22 2016
Dry and mild as upper level ridging develops over the area late
Sunday. With the peak of the ridge in place over the northern
plains Monday, southerly flow will be breezy with gusts near 25
mph across central and western North Dakota.
A short wave and low pressure system looks to develop on Tuesday
over the central plains with some wrap around rain entering
eastern North Dakota Tuesday into early Wednesday. As of now the
ECMWF is slower and favors a more northern track of the central
plains low and is wetter than the GFS solution. Upper level
ridging again builds over the region behind these two waves,
bringing mild and mainly dry conditions through the remainder of
the work week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 218 PM CDT Sat Oct 22 2016
Surface low pressure in central South Dakota will move northeast
today. VFR at all tafs initially. MVFR ceilings expected to
develop KMOT-KJMS after 08z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...MM
AVIATION...WAA
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
440 PM EDT Sat Oct 22 2016
.SHORT TERM...(This evening through Sunday night)
Issued at 345 PM EDT SAT OCT 22 2016
19Z sfc analysis shows high pressure building into the area as low
pressure pulls away to the east. This is working to clear the sky
from west to east as the drier air advects in on northwest winds.
In general, the winds are running at 5 to 10 mph with a few gusts
to 15 mph, or so, thanks to good mixing. The return of sunshine
helped temperatures this afternoon climb into the mid 50s for
most locations while dewpoints mixed down to the low and mid 30s.
These lower dewpoints should make it tougher to get fog late
tonight but may hint at a potential for valley frost.
The models are in good agreement aloft through the short term
portion of the forecast as they all depict a large trough
gradually pivoting out of the Ohio Valley. The core of the initial
trough will depart tonight with heights rising locally, but
additional energy does dive into the Great Lakes, though on a
more shallow trajectory, Sunday night. Given the good model
agreement will favor a blended solution with a lean toward the
higher resolution HRRR and NAM12.
Sensible weather will feature a chilly night with mostly clear
skies and good radiational cooling. This should be enough for
some upper 30s in the valleys and a spot or two of mid 30s where
patchy frost is possible. Do not anticipate the frost being
extensive enough for an advisory tonight as it will be confined
to just the deepest, most sheltered valleys. Accordingly, will
highlight it in the HWO with a the potential for an SPS left to
the following shift. Saturday will be a very nice mid autumn day
with plenty of sunshine, breezy conditions, and temps in the mid
60s. A few wind gusts will approach 30 mph Sunday afternoon over
western parts of our area. Another cool night follows with mostly
clear skies and another ridge to valley temperature split, but
likely not quite cold enough for any frost.
Used the CONSShort and ShortBlend as a starting point for the
grids with some adjustments each night for lows - enhancing the
ridge to valley differences. PoPs are essentially zero - in line
with all guidance.
.LONG TERM...(Monday through Saturday)
Issued at 440 PM EDT SAT OCT 22 2016
The models are in fairly good agreement aloft through the bulk of
the extended. A flat ridge will spread through the South during
the first part of the week before another wave starts developing
over the Northern Plains moving east. It is this wave that leads
to a greater spread in the models as it moves into the Upper
Midwest with the GFS outpacing the ECMWF and both stronger than
the Canadian. The wave deepens into a strong trough Wednesday
into Thursday - deepening substantially as it moves into and
through the Great Lakes to end the work week. Its energy brushes
by the Ohio Valley with its trough axis passing through Kentucky
early Friday. Heights will then rise for next weekend, more so
from the GFS, and quicker, than the ECMWF. Given the broad
agreement through the majority of the period a blend looks to be a
reasonable starting point for the grids.
Sensible weather will feature a fairly nice stretch of weather
through mid to late week with dry conditions and moderating
temperatures. A dry front will shift east of the area Monday with
little change in air mass. The next cold front will move toward
and through the area on Thursday with a decent shot at showers
into Friday morning. Cannot rule out a stray thunderstorm with
this, but given the time of year will wait until it gets closer
to further evaluate the thunder threat. Dry weather follows into
the weekend, but there may be another front worthy of some PoPs by
Saturday afternoon per the GFS and that night in the ECMWF. For
now, will keep it dry Saturday while the models work this
difference out.
The main adjustments to the CR init was to hit the terrain effects
more each night and tighten up the PoPs late in the upcoming work
week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 150 PM EDT SAT OCT 22 2016
VFR conditions will be the rule throughout the period. Scattered
to broken stratocu in the 4-6k feet agl range will break up and
thin from west to east during the rest of the afternoon - SKC
conditions then follow through the night. Any fog will be
confined to the deepest river valleys towards dawn and not impact
the TAF sites. Northwest winds will continue at 5 to 10 kts, with
an occasional gust to 15 kts, through early this evening, before
diminishing thereafter. Winds will pick up again after mid morning
on Sunday with some gusts approaching 20 kts by afternoon under
clear/sunny skies.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...GREIF
AVIATION...GREIF