Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/28/16
Area Forecast Discussion
National Weather Service Bismarck ND
940 PM CST Sun Nov 27 2016
.UPDATE...
Issued at 933 PM CST Sun Nov 27 2016
No significant changes with this update. Based upon trends in the
12-00 UTC global suites and the high resolution iterations through
02 UTC, have increased the wording to isolated areas of 15 inches
of storm total snowfall by Wednesday evening. This is in line with
the WPC afternoon forecast. Through 0330 UTC precipitation per
reports and webcams is transitioning from rain through sleet and
now snow in Glen Ullin, New Salem and Bismarck. This is generally
on time with the previous forecast thinking of change over.
UPDATE Issued at 647 PM CST Sun Nov 27 2016
As of 0045 UTC...rain is the predominant precipitation type across
south central North Dakota. Road temperatures are holding in the
34-36 degree range. Thus, at the time the freezing rain potential
seems somewhat lower given the road temperatures expected take a
few more hours at least to cool to freezing. However, by that time
across the south central, the 22-23 UTC RAP and HRRR suggest
precipitation is expected to begin its transition to mostly snow
in the 04-06 UTC timeframe. A mix is favored through the night and
and through much of Monday across the James River Valley. Given a
slightly quicker onset of precipitation, did adjust the Winter
Storm Warning start time to 01 UTC for south central North Dakota.
&&
.SHORT TERM...(This evening through Monday Morning)
Issued at 236 PM CST Sun Nov 27 2016
A major winter storm will impact western and central North Dakota
beginning tonight.
A negatively tilted upper level trough will swing into the
Northern Plains tonight. This will induce rapid cyclogenesis over
the central and northern plains with a 975-980MB surface low
situated somewhere near the ND/SD/MN border by 6 AM Monday. Ahead
of this, abundant moisture will stream into the eastern Dakotas,
with strong forcing from the leading shortwave inducing
precipitation over the James River Valley as early as this
evening, but certainly by midnight tonight.
As the system deepens and becomes stacked tonight, a well defined
trowal develops, spreading precipitation westward into central and
eventually western ND by Monday morning. Models continue to
indicate a brief period of warmer temperatures aloft and the
potential for freezing rain and sleet over portions of the James
River Valley this evening. Temperatures will remain near the
critical freezing threshold for much of the overnight and daytime
hours of Monday across the James Vally. Eventually colder air will
advect in and change the rain/freezing rain to all snow by Monday
night. For these areas a Winter Weather Advisory has been issued
to highlight the potential for freezing rain tonight and
accumulating snow tomorrow through Wednesday. Due to the delay in
switching over to snow, portions of Foster, Stutsman, LaMoure and
Dickey Counties will see less snow than locations further west.
.LONG TERM...(Monday through Saturday) Issued at 236 PM CST Sun
Nov 27 2016
Deterministic and ensemble model guidance have come into pretty
good agreement in the evolution of this storm. The deep low near
the ND/SD/MN border Monday morning moves very little through
Tuesday morning. The stacked system moves slowly east across
Minnesota through Wednesday morning, and finally lifts into the
Great Lakes region by Thursday.
With such a deep and slow moving system there is the potential for
significant snowfall across most of western and central ND Sunday
night through Wednesday night. The brunt of the snowfall is
expected from late Sunday night through Tuesday morning as the
warm moist air continues to feed into western and central ND via
the TROWAL. Winds with this strong system will increase over
western ND on Monday and spread into central ND Monday night and
Tuesday. At this time it looks the snow will be wet enough and
winds will be low enough to keep Blizzard conditions from forming,
but this could change if temperatures are little cooler and winds
a little higher. Regardless winds around 30 mph will cause some
blowing and drifting of snow, limiting visibility and making
travel hazardous. Therefore, a Winter Storm Warning has been
issued for all of western and most of central North Dakota. The
heaviest snow is expected across central North Dakota where 6 to
12 inches could accumulate by Wednesday. The TROWAL begins to
break down Tuesday evening, but synoptic forcing will remain
sufficient to produce light snow through Wednesday night.
Accumulations will become much lighter during this period, but
winds will remain strong through Tuesday evening.
There are still some uncertainties with this storm system. The
biggest being snowfall accumulations, and the potential for
blowing and drifting snow. Due to our very warm November, soil
temperatures remain in the mid 30s to lower 40s. Road surface
temperatures will also be warm during the beginning portions of
this storm. A heavy wet snow is expected initially with a reduced
threat of widespread blowing snow. This combination may initially
limit the severity of impacts, but later as temperatures drop and
surfaces freeze widespread travel impacts are expected.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 933 PM CST Sun Nov 27 2016
A winter storm will impact all of western and central North Dakota
tonight through Wednesday. Significant hazards to aviation are
expected. Flight categories will to fall to LIFR for all
terminals.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 PM CST /5 PM MST/ Wednesday for
NDZ019>023-034>036-042-045>047-050.
Winter Storm Warning until 6 PM CST /5 PM MST/ Wednesday for
NDZ001>005-009>013-017-018-031>033-040-041-043-044.
Winter Weather Advisory until 6 PM CST Wednesday for NDZ025-037-
048-051.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...AYD
Area Forecast Discussion
National Weather Service State College PA
958 PM EST Sun Nov 27 2016
.SYNOPSIS...
A narrow north to south ridge of high pressure will slide east
across Pennsylvania tonight and Monday, accompanied by dry weather
with light wind. A frontal system will develop over the plains
states and push a cold front through PA on Tuesday. A second storm
will follow shortly after. It will be mild and wet in the middle
of the week, with cooler air and lake effect snow showers
returning for the end of the week.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
A NNW-SSE stripe of stratocu clouds will exit our far eastern
zones by 05Z followed by just a brief hour or two period of
mainly clear skies...that will allow temps to dip several degrees
or more and into the 20s.
Patchy dense valley ground has formed in this ribbon of clearing
across the NW mtns where moist ground from snowmelt has added the
necessary near sfc moisture. Last few HRRR runs captures this fog
formation best via its sfc RH field and near 100 percent values
across the nrn mtns. This area of high RH advects steadily to the
east and out of the northcentral mtns by 08Z, as a cirrus/cs
shield overspreads the region and a light serly breeze develops.
The high cloud shield will also help to level off temps late.
Min temps look rather seasonable in the mid 20s to around 30F.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
8H temps rise early in the day, and Monday seems like the best
day for quite a few. High clouds will thicken-up from the west,
but it should remain dry until the evening. A sprinkle may occur
over the nrn mtns late in the day as moisture associated with warm
advection from the next system spills over the migratory upper
ridge. Maxes will get 5 to 10F above normal (m40s-l50s) thanks to
the light southerly wind and despite the meager mixing which
limits our tap into 9H temps of +2 to 5C.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Storm system centered over Minnesota will bring unsettled/stormy
weather through midweek. Models agree with an occluded front
swinging through the area Mon night/Tuesday accompanied by an area
of widespread light to occasionally moderate rain. Behind that on
Tue night, a brief period of relative drying out as shortwave
ridge slides through. Some minor differences in detail arise
thereafter, but models showing another significant wave forming on
the trailing front and spreading another slug of rain up over the
area by early Wednesday. Heaviest rain looks to be over the SE in
highest PWAT air, where a period of moderate rain is likely.
By late week, the upper low morphs eastward across southern
Canada, ushering in a prolonged period of cold NW flow aloft and
breezy conditions at the surface. The airmass doesn`t look
especially frigid, but it should be cold enough to provide an
extended period of widespread cloudiness and frequent lake effect
snow showers over the the NW mountains down into the Laurel
Highlands, possibly lasting all weekend long.
Temps become mild Tue/Wed with highs back up into the 50s/lower
60s. Thu will be a transition day back to colder temps with late
week/weekend just a shade below normal.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Main concern this evening is at KBFD, where clearing skies have
resulted in dense fog. 00Z obs reporting 1/4SM visibility, but
based on surrounding obs and satellite view, it appears to be an
isolated pocket of fog. Difficult to determine how long the dense
fog will persist, as a developing southerly breeze and increasing
high clouds could lead to improving conditions later this evening.
For now will go with the idea of improvement later this evening,
but there is a lot of uncertainty and low vsbys could potentially
persist well into the night.
Elsewhere across Central Pa, high pressure building into the
region will bring clearing skies and light wind overnight. Will
have to watch for the possibility of some patchy valley fog
around dawn at KIPT. However, GLMP MELD suggests the odds are
fairly low.
Any early fog should lift shortly after 12Z, then model data
supports a high confidence of widespread VFR conditions the rest
of the day, as high clouds overspread the state in advance of an
approaching storm system.
Outlook...
Tue...Low cigs/rain, mainly in the morning.
Wed...Rain/low cigs possible.
Thu-Fri...Restrictions possible KBFD/KJST in scattered snow
showers.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Dangelo
LONG TERM...La Corte/RXR
AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service Hastings NE
543 PM CST Sun Nov 27 2016
.SHORT TERM...(This evening through Monday)
Issued at 318 PM CST Sun Nov 27 2016
Current radar has showers and maybe an isolated thunderstorm moving
through the central to northeast part of the forecast area.
Satellite shows clearing in or near the southwest portion of the
area this afternoon. Surface analysis still has the low pressure
system near the Nebraska/Kansas/Colorado borders.
The main question for the remainder of the afternoon and into the
evening is if there will be enough instability near the clearing
line to start a few thunderstorms. The HRRR has been consistent with
having some convection that starts in the north central Kansas
counties and moves to the northeast from there. There is also a
small area that starts up in the west before moving to the
northeast. The best timing for the thunderstorms will be from about
3pm to 6pm. There is still a question as to how much instability
there will be. The RAP brings a small area of 500 to 1000 j/kg into
the southwest and pushes it across as it weakens. Once the sun goes
down this evening, that should effectively cut off chances for
thunder.
The precipitation should move off to the northeast of the forecast
area during the evening hours and there should be some clearing
behind the precipitation. As the surface low moves to the
east/northeast into this evening. The winds should turn to the west
and bring in drier air to the area during the evening hours. The
clearing skies and drier air should allow temperatures to fall off
into the mid 30s.
A little wrap around moisture will bring some clouds back to the
area for a time on Monday, but the clouds will move out during the
afternoon. Temperatures will warm back into the lower 50s during the
afternoon.
.LONG TERM...(Monday night through Sunday)
Issued at 318 PM CST Sun Nov 27 2016
There will be mostly northwest flow across the area through this
period. There are a few waves that move through the area. Have kept
the forecast dry through the period, but each of the waves brings an
increase in cloud cover and a weak cold front. The first wave moves
through Monday night. Temperatures will be cooler Tuesday and there
will be a few more clouds around. Temperatures will remain cooler
than normal with in and out clouds Wednesday through Friday. A
surface high moves through the area on Friday and when it moves to
the southeast Friday night, winds will turn back to the south and
temperatures will start a slow increase back to near normal for the
weekend.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday evening)
Issued at 539 PM CST Sun Nov 27 2016
The main issue with this forecast is low-level wind shear this
evening and into the early overnight. Most showers/thunderstorms
have moved off to the east and we should be dealing with VFR
conditions. Wind speeds will initially be quite gusty, but should
let up somewhat as the cold front approaches. Wind speeds will
pick back up again behind the cold front later on tonight and into
Monday.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...JCB
LONG TERM...JCB
AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Lincoln IL
902 PM CST Sun Nov 27 2016
.UPDATE...
Issued at 902 PM CST Sun Nov 27 2016
Initial wave of rain has progressed eastward slightly ahead of
model projections, and there appears to be a back edge of the rain
approaching from across Missouri ahead of previous forecasts as
well. The faster pace may be partly due to the intense low and mid
level winds out of the southwest that have developed this
evening. Winds 1-2K ft above the ground are up to 40-50kts based
on VWP plots from the ILX radar. Surface winds have sustained up
around 20 mph with gusts over 30 mph at times. HRRR and RAP
updates are showing the faster progression of the first wave of
rain, so we have followed suit in the PoP and weather grids for
the next 12-18 hours.
Thunder has not materialized in Illinois, nor Missouri for that
matter, so we removed any mention of storms from the rest of the
night.
Low temps will be help warmer due to blanket of clouds, periodic
rains, and strong ground level winds. Forecast lows are not much
below current air temps, so expect relatively steady temps
overnight.
Updated forecast info is already available.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 230 PM CST Sun Nov 27 2016
Early afternoon surface map shows surface low organizing across
northwest Kansas, as the upper low takes shape over eastern parts of
Montana and Wyoming. The earlier stratus continues to lift
northeastward and the southern half of the forecast area is mainly
seeing mid and high level clouds at this point. A few showers have
grazed the western CWA as of late, but the more organized
precipitation is steadily advancing across southern Iowa and
northern Missouri and should reach the middle Illinois River Valley
by late afternoon.
Morning model suite continues to indicate a rapid intensification of
the surface low as it lifts into eastern South Dakota this evening,
before it begins to occlude later Monday over eastern North Dakota.
Showers will continue to steadily advance across the forecast area
this evening and have gone with categorical PoP`s at most locations
tonight. Have added some isolated thunder mention as well. The
initial dry slot behind this band of showers will spread across the
western CWA late tonight, and rain chances will be somewhat minimal
for a time over a large area west of I-55 early Monday. The higher
PoP`s for the afternoon still look good though, as a wave ejects
northeast out of the Desert Southwest and sends another surge of
moisture northward ahead of the cold front. Precipitable water
values approach 1.1-1.2 inches south of I-70, which will help with
some healthy rain totals near an inch during the daytime.
The mild temperatures -- lows in the lower 40s and highs in the
lower 50s -- will be offset by wind gusts of 30-35 mph at times over
central Illinois overnight and Monday.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 230 PM CST Sun Nov 27 2016
The main cold front associated with the weather system moving
through the area, will quickly move through the remainder of the CWA
Monday evening. As it does, most areas will see an end to the precip
by midnight, with just a chance of precip in the eastern parts of
the CWA. Dry weather is then expected behind this front. However,
central IL will remain in a cyclonic flow pattern through most of
the week, with the associated surface low slowly moving east
northeast across the Great Lakes region. The models do develop a
secondary surface low that moves across northern IL; but, since
there will also be another weather system in the southern Miss
valley at the same time, moisture will be limited for the northern
system in our area. So, for Tue night, when this moves through, dry
weather is still expected over most of the CWA, with a slight chance
of precip in southeast IL from the southern system. The upper level
low will finally move into eastern Canada toward the end of the
week, bringing a change in the pattern for the weekend. The
resulting pattern seems to be one with a split flow as an upper
level low sets up in the southwest US and a northwest flow pattern
sets up over the norther US and Great Lakes region. This should keep
things somewhat quite over the area, but the ECMWF brings a weather
system across Illinois for Sunday. Since this is the first run with
that and the GFS is dry, pops for Sunday will only be slight chance
for now.
Colder air will lag behind the weather system Mon night so high
temps Tuesday will still be above normal, reaching the 55 to 60
degree range. Given the pattern, the colder air does not really make
into the CWA until Wed night. So, Wed highs will be slightly above
normal for end of November. Normal to slightly below normal temps
can then be expected Thur through next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 603 PM CST Sun Nov 27 2016
Rain has already reached SPI and PIA and will overspread the
remainder of the TAF sites by 03z. VFR clouds ahead of the rain
will drop to MVFR a couple of hours after rain onset. Periods of
light to moderate rain are expected this evening. Radar images
upstream indicate we will see breaks in the rain after the first
2-3 hours of steady rain at the onset. A warm front will lift
northeast through Illinois later this evening, prompting a
lowering of ceilings to IFR and possible MVFR fog development at
all terminals tomorrow morning. Cloud heights and visibility in
fog are projected to drop even further tomorrow afternoon, with
1-2SM BR and OVC004 become widespread.
South winds will increase this evening and remain strong the
remainder of this TAF period, in response to a tightening pressure
gradient and LLJ winds mixing to the surface. We are expecting
sustained winds of 18-20kt with gusts over 30kt at times.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Geelhart
LONG TERM...Auten
AVIATION...Shimon
Area Forecast Discussion
National Weather Service Marquette MI
640 PM EST Sun Nov 27 2016
.SHORT TERM...(This evening through Monday)
Issued at 356 PM EST SUN NOV 27 2016
WV imagery and RAP analysis indicated a mid/upper level trough over
much of the wrn CONUS, from the Rockies into the wrn plains. A
vigorous lead shortwave was lifting northeast into wrn IA. At the
surface, se winds were increasing between a 989 mb low over sw
Nebraska and a ridge from Quebec into the ern Great Lakes. With
daytime warming, low level moisture trapped below a 1k-2k ft
inversion has lifted to a low stratus deck over most of the cwa
except over portions of the west where downslope se flow was
strongest.
The short range models were in good agreement with the
progression/onset of the rain ahead of the IA shrtwv and surge of
295k-305k isentropic lift. Expect the rain developing from sw to ne
between 06z-12z to taper off during the morning after the initial
band moves through. Although the mid level moisture will depart
during the day, continued low level isentropic lift will maintain
some light rain or drizzle through most of the day, with lower
amounts and coverage near Lake Superior where the strongest
downslope wind prevails. Fog may thicken again tonight with the loss
of sfc heating but with the rain moving in, should not be as dense
into Monday as it was this morning. Temps will remain steady or
slowly rise tonight and then climb just a few degrees to the lower
to mid 40s Monday.
.LONG TERM...(Monday night through Sunday)
Issued at 405 PM EST SUN NOV 27 2016
Positive height anomalies currently dominating much of the east half
of Canada will expand across most of Canada by midweek, then
diminish in magnitude/coverage next weekend. To the s, energy
flowing off the ne Pacific will carve out the long advertised
central CONUS trof over the next few days. This trof will then
evolve to a positive tilt from se Canada/New England to the sw CONUS
by late week. Next weekend, lower amplitude flow looks to develop
briefly across the northern CONUS/southern Canada prior to trof
development in the vcnty of far western N America in the 8-10day
period. This trof development will herald a potential pattern change
across N America heading into mid Dec that will initially lead to
advection/build up of arctic air into western Canada. Ahead of the
developing central CONUS trof in the shorter term, southerly flow
will push temps well above normal across the area over the next
couple of days. While temps will fall back closer to normal later in
the week as the trof axis drifts e, readings should remain a little
above normal as the positive height anomalies across Canada prevent
any arctic air from developing or dropping s thru Canada and into
the CONUS. As for pcpn over the next 7 days, the developing central
CONUS trof will bring a wet period into early Tue with all of the
pcpn in the form of rain. Pcpn will then transition to ocnl lighter
snow mid and late week with troffing over the area, though there
will be potential of lake enhanced snow that may provide some
accumulations. Looking farther ahead beyond this 7 day fcst,
CPC/NAEFS outlooks in the 8-14 day period, out to Dec 11, now show
diminishing probabilities of above normal temps as the start of the
potential pattern change moves into that time period. Farther out,
CFSv2 runs continue to show the pattern change toward colder weather
heading into mid Dec as positive height anomalies that have
dominated Canada for many weeks give way to negative height
anomalies. The changes shown are consistent with GFS/ECMWF trends
for early next week which show western N America trof development
initially which leads to advection/build up of arctic air in western
Canada. Could be an active period of weather as this cold air shifts
farther e and se. However, it is noted that the majority of Canadian
ensembles valid Dec 13 have a mild look for the Upper Lakes.
Beginning Mon night/Tue, the second of 3 significant pieces of
energy moving thru the central CONUS trof will lift into the Great
Lakes. This second wave will have stronger jet dynamics/upper
diffluence and stronger deep layer forcing compared to the first
wave that generates pcpn tonight/Mon. Result will be heavier
rainfall affecting the fcst area Mon night into early Tue morning,
especially across the central and eastern fcst area. Potential is
there for 1+ inch of rainfall over roughly the e half where stronger
forcing better overlaps warm conveyor belt deep moisture ribbon
which has precipitable water around 0.80 inches/250pct of normal.
Passage of occluded front to the n and ne Tue morning will then
bring an end to the steadier/heavier rain. Models have been trending
more toward a dry period following fropa under mid level drying.
Fcst will follow suit, but will retain a schc mention over the far w
Tue aftn, closer to mid level low center over MN. Expect low temps
Mon night in the upper 30s/lwr 40s. High temps on Tue may reach 50F
over the e, especially if clouds break, while low/mid 40s will be
the rule w.
It now appears that the 3rd piece of significant energy moving thru
the central CONUS trof will probably have a track far enough w to
spread deep layer forcing and deep moisture back into Upper MI on
Wed, especially across the e. Given multi-model trends, fcst will
show chc pops spreading across the e and much of the central fcst
area on Wed. Wetbulb zero heights support only rain as ptype. Over
the far w, deep moisture in the vcnty of the decaying mid level low
may support some -shra, perhaps mixed with snow.
Thu into Fri, fcst area will be under the influence of the gradually
weakening mid/upper level trof that will extend from se Canada to
the sw CONUS at the end of the week and the associated sfc trof.
With deep moisture and 850mb temps gradually falling to -5 to
-8C, expect some -shsn/-shra transitioning to mainly -shsn across
the area. There is the potential of lake enhanced snow off Lake
Superior, dependent on location/movement of the sfc trof across the
Upper Lakes. ECMWF is much sharper with this trof, offering
potentially mdt snow accumulations in the Lake Superior snow belts
Wed night/Thu. Not a lot of consistency run-to-run and btwn models
with the details, but this will be a time period to monitor for some
snow accumulations in the Lake Superior snow belts, especially
across the higher terrain of western Upper MI and then e toward
Marquette. Light LES will then continue into Fri.
Model trends are quicker toward a transition to a lower amplitude
more zonally oriented flow over the weekend. There will likely be a
shortwave passing during this transition period, but any pcpn that
might occur should be light.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 639 PM EST SUN NOV 27 2016
Continuing moist SE flow ahead of the approaching sfc low will keep
ceilings low across the three TAF sites overnight an into Monday. SE
flow favors keeping ceilings LIFR/IFR at KSAW and IFR at KCMX. KIWD
to see low end MVFR/IFR as SE flow is downslope there. Ceilings do
improve to MVFR late in the forecast at KIWD and KCMX but KSAW will
remain IFR/LIFR.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 356 PM EST SUN NOV 27 2016
High pressure over the ern Great Lakes will shift to the east
tonight as low pressure deepens across the northern plains into the
upper midwest. This will result in a tight pressure gradient
developing across the northern Great Lakes creating gales overnight.
Gales to 40kt are expected across all of Lake Superior spreading
west to east, but the gradient will slacken earliest across the far
west. Further east the gradient will remain tight, with gales
lingering through Mon night. The low pressure system will linger
over the upper midwest Tuesday into Wednesday. However the pressure
gradient is not expected to be as tight and allow winds to diminish
below 25kt by Tuesday evening. Northerly winds to around 25 knots may
develop Thursday as the slow moving low moves to the east of Lake
Superior into Quebec.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Warning from midnight tonight to 10 AM EST Tuesday for
LSZ249>251-266-267.
Gale Warning from midnight EST /11 PM CST/ tonight to 10 AM EST
/9 AM CST/ Monday for LSZ162.
Gale Warning from midnight tonight to 4 AM EST Tuesday for
LSZ243-244-264.
Gale Warning from midnight EST /11 PM CST/ tonight to midnight
EST /11 PM CST/ Monday night for LSZ240>242-245>248-263-265.
Lake Michigan...
Gale Warning from 4 AM Monday to 4 AM EST Tuesday for LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...Rolfson
AVIATION...RJT
MARINE...JLB
Area Forecast Discussion
National Weather Service Norman OK
909 PM CST Sun Nov 27 2016
.DISCUSSION...
Recent runs of the HRRR develop convection southwest of Wichita
Falls between 1 and 2 am with further develop to the north and
east through 7 am. However, some weak returns around Big Springs
and Synder may indicate storms may form before midnight.
Regardless, it appears south central and southeast Oklahoma will
have a good opportunity for showers and storms tonight with strong
winds and hail possible with the strongest storms. Storms will
move very quickly and storm tops should be below 30k feet.
&&
.PREV DISCUSSION... /issued 244 PM CST Sun Nov 27 2016/
DISCUSSION...
Latest water vapor satellite imagery reveals one lead shortwave
trough emerging from the Central Rockies onto the Central High
Plains, and another moving through Nevada. The first shortwave
trough has resulted in strong surface pressure falls in the lee of
the Rockies and latest surface analysis shows a 988 mb surface low
in far northwest Kansas. Strong winds have resulted across
Oklahoma and western north Texas. Maximum gusts have been around
40 mph across northwest Oklahoma. The stronger winds have been
confined to the Oklahoma and Texas panhandles where deeper mixing
is occurring and gusts over 50 mph have been common. The strongest
winds in our area through sunset will be where partial clearing
and deeper mixing has occurred across far northwest Oklahoma. As a
Pacific cold front moves east and winds veer, gusts approaching 50
mph may be possible across this area until mixing subsides early
this evening. Otherwise, low stratus has been persistent across
the entire area all day and this will continue into the night with
gradual clearing from the west.
Short term model guidance continues to show a low-level theta-e
corridor ahead of the front slowly moving eastward. As
aforementioned lead shortwave lifts northeast the front/moisture
axis will linger and slowly move eastward. Cooling aloft/ascent
ahead of the next shortwave trough (now over Nevada and moving
quickly east) will overspread this moist axis and should result in
isolated/scattered convection developing late this evening and
continuing into the night. Low level moist advection beneath
steepening mid level lapse rates should contribute to at least 500
J/kg to perhaps 1,000 J/kg MUCAPE from parcels that should
originate just above the surface. This combined with strong deep
layer shear in excess of 60 knots should lead to organized/intense
thunderstorms and a few may be marginally severe. Marginally
severe hail is the most likely severe threat given somewhat
stable boundary layer limiting the wind/tornado threat. Having
said that, given the very strong momentum aloft, a few severe wind
events are possible. Spatial details of convection are not quite
clear but it does appear the potential exists further northwest
than originally thought, possible as far northwest as north-
central Oklahoma, by late evening. Convection will probably expand
in coverage toward the south and east and be most numerous later
in the night across south-central and especially southeast
Oklahoma.
Rain chances will end early tomorrow as the second shortwave
trough departs. A period of mean westerly/downsloping flow should
result in slightly above normal temperatures tomorrow. The
combination of a drier air mass and breezy conditions may lead to
elevated to near critical fire weather conditions across western
portions of our area (see Fire Weather Discussion below).
The weather will be uneventful through Thursday with the only
notable change being a cold front forced by head another shortwave
trough rotating around large/deep Midwest closed low. This cold
front will arrive on Tuesday and keep temperatures from warming
nearly as much as is anticipated tomorrow. Highs in the 50s will
be common in all but the southern portion of the area where the
front will arrive later. Even colder temperatures are expected
Wednesday as northerly flow and cold advection keep temperatures
in the 40s across the northern portion of the area. Low amplitude
ridging aloft will bring moderating temperatures (to near late
November normals) on Thursday.
A complicated scenario develops by Friday and especially this
weekend. Inconsistencies and disagreements among medium range
guidance leads to a low confidence forecast. Beginning late
Friday and persisting through the night, most of the deterministic
and ensemble guidance shows a broad/weak isentropic ascent
scenario with sufficient moistening for precipitation. This
occurs ahead of a deepening increasingly closed off mid-upper low
that will be positioned to our west. Variances in the synoptic
scale details with the pattern across the Midwest into the
Northeast have implications for precipitation type for us. Some
solutions are more robust with a cold surge into our area early on
that would be sufficient for snow across at least the northern
portion of the area. However, the GEFS mean and ECMWF
deterministic have trended less anomalously negative with 500 mb
heights across the northeast indicated that the first cool surge
may be less significant and confined to just the northern portion
of the area. The new 12z ECMWF is the most concerning for our area
with regards to cold/snow and potential winter weather impacts. It
shows the Southwest closed low phasing with northern stream wave
and accelerating east, passing to our south. This scenario would
bring a second more defined cold surge southward coincident with
large scale ascent spreading over the area. The GFS and its
ensembles as well as the Canadian are more closed off with this
system and have it out of phase with this northern stream wave,
however. If medium range guidance trends toward the latest ECMWF,
this would necessitate higher precipitation probabilities for
Saturday and more potential for snow.
BRB
FIRE WEATHER...
Mimimum relative humidity values are expected to fall to between
20 and 25 percent across much of western north Texas and perhaps
far southwest Oklahoma tomorrow afternoon. This may be somewhat
mismatched with when the highest winds are expected (earlier in
the day) thus limiting the fire weather concern. Still, 15 to 20
mph sustained 20 foot winds will lead to elevated to near critical
fire weather conditions across this area.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 50 66 40 56 / 30 10 0 0
Hobart OK 45 66 38 56 / 20 10 0 0
Wichita Falls TX 52 70 45 64 / 30 10 0 0
Gage OK 37 63 32 51 / 10 0 0 0
Ponca City OK 48 64 36 54 / 40 10 0 0
Durant OK 59 70 46 65 / 80 40 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
Area Forecast Discussion
National Weather Service Bismarck ND
1250 AM CST Mon Nov 28 2016
.UPDATE...
Issued at 1250 AM CST Mon Nov 28 2016
Inherited forecast is mainly on track. I did increase winds Monday
night into Tuesday. We start to see pressure rises develop west
into central Monday night along with an increase in gradient
forcing, which continues Tuesday. 1000-850mb geostrophic winds
range from 50-60KTs as well during this time frame.
UPDATE Issued at 933 PM CST Sun Nov 27 2016
No significant changes with this update. Based upon trends in the
12-00 UTC global suites and the high resolution iterations through
02 UTC, have increased the wording to isolated areas of 15 inches
of storm total snowfall by Wednesday evening. This is in line with
the WPC afternoon forecast. Through 0330 UTC precipitation per
reports and webcams is transitioning from rain through sleet and
now snow in Glen Ullin, New Salem and Bismarck. This is generally
on time with the previous forecast thinking of change over.
UPDATE Issued at 647 PM CST Sun Nov 27 2016
As of 0045 UTC...rain is the predominant precipitation type across
south central North Dakota. Road temperatures are holding in the
34-36 degree range. Thus, at the time the freezing rain potential
seems somewhat lower given the road temperatures expected take a
few more hours at least to cool to freezing. However, by that time
across the south central, the 22-23 UTC RAP and HRRR suggest
precipitation is expected to begin its transition to mostly snow
in the 04-06 UTC timeframe. A mix is favored through the night and
and through much of Monday across the James River Valley. Given a
slightly quicker onset of precipitation, did adjust the Winter
Storm Warning start time to 01 UTC for south central North Dakota.
&&
.SHORT TERM...(This evening through Monday Morning)
Issued at 236 PM CST Sun Nov 27 2016
A major winter storm will impact western and central North Dakota
beginning tonight.
A negatively tilted upper level trough will swing into the
Northern Plains tonight. This will induce rapid cyclogenesis over
the central and northern plains with a 975-980MB surface low
situated somewhere near the ND/SD/MN border by 6 AM Monday. Ahead
of this, abundant moisture will stream into the eastern Dakotas,
with strong forcing from the leading shortwave inducing
precipitation over the James River Valley as early as this
evening, but certainly by midnight tonight.
As the system deepens and becomes stacked tonight, a well defined
trowal develops, spreading precipitation westward into central and
eventually western ND by Monday morning. Models continue to
indicate a brief period of warmer temperatures aloft and the
potential for freezing rain and sleet over portions of the James
River Valley this evening. Temperatures will remain near the
critical freezing threshold for much of the overnight and daytime
hours of Monday across the James Vally. Eventually colder air will
advect in and change the rain/freezing rain to all snow by Monday
night. For these areas a Winter Weather Advisory has been issued
to highlight the potential for freezing rain tonight and
accumulating snow tomorrow through Wednesday. Due to the delay in
switching over to snow, portions of Foster, Stutsman, LaMoure and
Dickey Counties will see less snow than locations further west.
.LONG TERM...(Monday through Saturday) Issued at 236 PM CST Sun
Nov 27 2016
Deterministic and ensemble model guidance have come into pretty
good agreement in the evolution of this storm. The deep low near
the ND/SD/MN border Monday morning moves very little through
Tuesday morning. The stacked system moves slowly east across
Minnesota through Wednesday morning, and finally lifts into the
Great Lakes region by Thursday.
With such a deep and slow moving system there is the potential for
significant snowfall across most of western and central ND Sunday
night through Wednesday night. The brunt of the snowfall is
expected from late Sunday night through Tuesday morning as the
warm moist air continues to feed into western and central ND via
the TROWAL. Winds with this strong system will increase over
western ND on Monday and spread into central ND Monday night and
Tuesday. At this time it looks the snow will be wet enough and
winds will be low enough to keep Blizzard conditions from forming,
but this could change if temperatures are little cooler and winds
a little higher. Regardless winds around 30 mph will cause some
blowing and drifting of snow, limiting visibility and making
travel hazardous. Therefore, a Winter Storm Warning has been
issued for all of western and most of central North Dakota. The
heaviest snow is expected across central North Dakota where 6 to
12 inches could accumulate by Wednesday. The TROWAL begins to
break down Tuesday evening, but synoptic forcing will remain
sufficient to produce light snow through Wednesday night.
Accumulations will become much lighter during this period, but
winds will remain strong through Tuesday evening.
There are still some uncertainties with this storm system. The
biggest being snowfall accumulations, and the potential for
blowing and drifting snow. Due to our very warm November, soil
temperatures remain in the mid 30s to lower 40s. Road surface
temperatures will also be warm during the beginning portions of
this storm. A heavy wet snow is expected initially with a reduced
threat of widespread blowing snow. This combination may initially
limit the severity of impacts, but later as temperatures drop and
surfaces freeze widespread travel impacts are expected.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1250 AM CST Mon Nov 28 2016
A winter storm will impact all of western and central North
Dakota through Wednesday. Significant hazards to aviation can be
expected. Flight categories will fall to IFR-LIFR all terminals.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 PM CST /5 PM MST/ Wednesday for
NDZ001>005-009>013-017>023-031>036-040>047-050.
Winter Weather Advisory until 6 PM CST Wednesday for NDZ025-037-
048-051.
&&
$$
UPDATE...NH
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...NH
Area Forecast Discussion
National Weather Service Lincoln IL
330 AM CST Mon Nov 28 2016
.SHORT TERM...(Today and tonight)
ISSUED AT 328 AM CST Mon Nov 28 2016
A large and slow moving storm system will continue to impact central
and southeast Illinois through the period and beyond. The deep 976
mb surface low is currently centered over eastern South Dakota and
will move little over the next 24 hours. A tight pressure gradient
to the east of this system is providing gusty southerly winds across
the area, and these should persist through the period, with gusts to
40 mph possible at times.
While showers are moving out of the forecast area early this
morning, the break in the rainfall will be short lived. A second
strong short wave will help produce another round of showers from
midday today into this evening. The short wave that brought us
rainfall late yesterday to now tracked west of the forecast area,
while today`s wave is progged to track directly across the forecast
area. This track is supportive of better dynamics locally, as well
as steeper lapse rates. These factors favor including a mention of
thunder with today`s rainfall. The track of the wave will also
provide more of a gradient of QPF, with the eastern half of the
forecast area receiving more significant rainfall totals than the
west. Southeast Illinois is likely to see rainfall totals in excess
of 1 inch before the rain ends later tonight.
Much like in the past 24 hours, the next 24 hours will see
relatively small diurnal temperature ranges due to the clouds and
rainfall. Expect highs today in the lower 50s and lows tonight in
the 40s, both of which are well above normal for late November.
&&
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 328 AM CST Mon Nov 28 2016
The 00Z forecast models continue to show a fairly nice late fall day
on Tuesday over central and southeast IL, as a partly to mostly
sunny day unfolds. Breezy southerly winds bringing milder highs
in the upper 50s and lower 60s. MET guidance even as warm as 65F
at Jacksonville and Lawrenceville and if we get enough sunshine,
that could be achievable. Large low pressure system over the upper
MS river valley Tuesday will pivot a short wave trof and cold
front eastward across IL Tuesday night. The 00Z NAM model
continues to have some light qpf over areas along and north of a
Rushville to Bloomington line, where SPC day2 again shows general
risk of thunderstorms. Plume of steep mid level lapse rates will
advect over central IL Tue evening and be over a somewhat unstable
air mass with MUCAPES of several hundred J/kg. Have added slight
chance of showers/thunderstorms to northern CWA Tue evening.
Large upper level low/trof tracks east across the northern Great
Lakes Wed and Wed night and into southern Quebec and northern New
England on Thursday. This will bring more low clouds (especially
north of I-70) and cooler temperatures. Brunt of light rain/snow
showers, should mostly stay north of central IL, but get closest to
far northern counties Wed afternoon and early Wed evening. Highs Wed
range from mid 40s over IL river valley, to lower 50s in southeast
IL. Highs Thu in the lower 40s, with Lawrenceville near 45F. About 2
degrees cooler on Friday with highs in the upper 30s from I-74 north
and lower 40s south. Seasonably cool temperatures to continue Friday
and this weekend with dry weather Friday and Saturday. Some big
differences continue between the ECMWF and GFS model solutions on
Sunday, with ECMWF showing large area of qpf lifting northward over
IL while GFS model is dry and colder over IL. Made no changes to the
blended model guidance due to lack of confidence in forecast that
far out. Have slight chances of light rain/snow over southeast IL
overnight Sat night and across most of area on Sunday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1147 PM CST Sun Nov 27 2016
Despite steady rains all evening, cloud heights remained VFR. A
warm frontal boundary along the Illinois Missouri border is poised
to lift northeast through our forecast area the rest of the night.
Behind the front, ceilings drop to MVFR, as rainfall coverage
decreases significantly. Have introduced an extended period of
VCSH at all terminals starting at 07z for SPI and eventually
reaching CMI around 10z. HRRR and RAP show spotty showers still
possible during that time due to continued synoptic lift in the
warm sector. However, a band of dry mid-level air should limit
precip development until the next main push of moisture and
forcing for precip Monday afternoon. Have continued a downward
trend in ceilings and visibility with the onset of steady rains
Monday afternoon, with IFR and possibly LIFR ceilings and
visibility becoming widespread. Precipitation is projected to
quickly come to an end from SW to NE Monday evening, as VFR
conditions return.
Strong south winds will continue through Monday afternoon, with
20G30kt common. Winds will shift to the southwest Monday evening
with diminishing gusts somewhat, but we still expect sustained
winds of 15-19kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bak
LONG TERM...07
AVIATION...Shimon
Area Forecast Discussion
National Weather Service Miami FL
448 AM EST Mon Nov 28 2016
.DISCUSSION...
At 430 AM, doppler radar continued to show scattered light
showers avecting slowly westward from the Atlantic waters towards
portions of the east coast metro. However, little in the way of
accumulation is expected with this activity. The latest HRRR and
WRF model runs generate spotty light showers through the remainder
of this morning and into the afternoon across the CWA. Have
included a slight chance pops over nearly the whole CWA to
account for this. Surface high pressure will continue to build
across the western mid Atlantic waters today. This will help to
maintain breezy east southeast winds, especially along the east
coast metro, where gusts would reach around 15-20 mph.
Temperatures this afternoon should remain mild with highs in the
the upper 70s to around 80 degrees along the immediate east coast
to lower 80s further the west.
Tuesday through Wednesday, high pressure will maintain the east
southeast flow. Dry weather should prevail during this timeframe,
with the exception of a few brief light showers over the Atlantic
waters and east coast metro. Expect a slight warming trend with
maximum temperatures Wednesday and Thursday forecast to range from
the low to mid 80s across the entire region, around 5 degrees
warmer than normal for this time of year.
Thursday into Friday, both the GFS and ECMWF push yet another cold
frontal boundary southwards across the region. Ahead of this
feature, low level moisture and instability appear sufficient enough
to include a slight chance of scattered showers. Late this
weekend, models diverge with the GFS maintaining zonal flow and
the ECMWF developing a long wave trough and wetter pattern over
south Florida. Will a keep a slight chance of pops in the forecast
for Sunday, but confidence remains low.
&&
.MARINE...
Winds will shift to the east southeast today as high pressure
builds to the north of the region. Small craft advisories are in
effect for the Atlantic waters outside Biscayne Bay through this
evening for winds 15 to 25 KT and seas 5-7 feet, highest in the
Gulf Stream.
&&
.AVIATION...
VFR conditons through the TAF period. High pressure, currently to
the north, will slide to the east for the next several days. This
will cause the wind to turn more to the southeast on Monday.
Also, the wind will increase to around 15kts, and may have gusts
to around 25kts for a good part of the day. The wind is forecast
to subside in the evening hours.
In the easterly flow, some brief isolated showers may impact the
TAF sites along the Atlantic coast. However, they should have
little impact on flight conditions.
&&
.BEACH FORECAST...
There will be a high risk for rip currents through Tuesday morning
along the east coast beaches, due to the increasing onshore flow.
The risk may drop to moderate by midweek with weakening easterly
winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 81 72 83 74 / 20 20 10 10
Fort Lauderdale 80 73 81 75 / 20 20 10 10
Miami 81 72 83 73 / 20 20 10 10
Naples 83 66 85 68 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Tuesday morning for FLZ168-172-173.
AM...Small Craft Advisory until 1 PM EST this afternoon for AMZ651-
671.
Small Craft Advisory until 7 PM EST this evening for AMZ650-670.
GM...None.
&&
DISCUSSION...27/JT
MARINE...27/JT
AVIATION...13
BEACH FORECAST...27/JT
Area Forecast Discussion
National Weather Service Marquette MI
424 AM EST Mon Nov 28 2016
.SHORT TERM...(This evening through Monday)
Issued at 356 PM EST SUN NOV 27 2016
WV imagery and RAP analysis indicated a mid/upper level trough over
much of the wrn CONUS, from the Rockies into the wrn plains. A
vigorous lead shortwave was lifting northeast into wrn IA. At the
surface, se winds were increasing between a 989 mb low over sw
Nebraska and a ridge from Quebec into the ern Great Lakes. With
daytime warming, low level moisture trapped below a 1k-2k ft
inversion has lifted to a low stratus deck over most of the cwa
except over portions of the west where downslope se flow was
strongest.
The short range models were in good agreement with the
progression/onset of the rain ahead of the IA shrtwv and surge of
295k-305k isentropic lift. Expect the rain developing from sw to ne
between 06z-12z to taper off during the morning after the initial
band moves through. Although the mid level moisture will depart
during the day, continued low level isentropic lift will maintain
some light rain or drizzle through most of the day, with lower
amounts and coverage near Lake Superior where the strongest
downslope wind prevails. Fog may thicken again tonight with the loss
of sfc heating but with the rain moving in, should not be as dense
into Monday as it was this morning. Temps will remain steady or
slowly rise tonight and then climb just a few degrees to the lower
to mid 40s Monday.
.LONG TERM...(Tuesday through Sunday)
Issued at 424 AM EST MON NOV 28 2016
Tuesday: The most significant issue Tuesday morning will be a
reinforcing shot of energy that will slide north and eastward from
northern Lower Michigan into southern Ontario. This wave of energy
will drag an associated surface lobe of low pressure across the same
area. The occluded front, stretching between the aforementioned
feature and the vertically stacked low over MN, will slide from
southwest to northeast, clearing the area between 15Z/29 18Z/29. The
better forcing will be will be over the east half and Lake Superior
before 15Z and then quickly slide out of the area with the
aforemention features. At this point, not expect more than an
additional 0.1 to 0.2 inches of additional rainfall over the east
half and the Keweenaw through the morning hours. The deep layer
moisture exits the area with the occluded front through the
afternoon, which should make for a dry afternoon with some breaks in
the clouds expected, especially across the south central and east.
Highs will be well above normal over the east half with most
locations expected to be in the upper 40s to around 50, while the
west half stays mainly in the low to mid 40s.
Tuesday night into Wednesday night: As the occluded front continues
to slowly slide north and east, the area should continue to remain
dry Tuesday night with increasing cloud cover once again ahead of
the next system. The next shot of energy is progged to slide near
the eastern U.P. late Tuesday night through Wednesday
evening.Theadded deeper moisture along with increased forcing, will
allow for another chance of showers moving through the area.
Additionally, the aforementioned occluded low will begin to slide
across the western U.P. by Wednesday afternoon, which will begin to
introduce precip chances over the far west once again. By that time,
cooler air will begin to move in aloft which may allow some snow to
mix in with the rain at times over the far west late Wednesday
afternoon into Wednesday night.
Thursday through the extended: The closed low will slowly meander
through the Upper Great Lakes region through Friday morning before
sliding out of the area Friday night into the weekend. As this
happens, colder air will begin to filter into the region, at the
surface and aloft, allowing the rain to transition to snow.
Currently it looks like the north to northwest wind favored
snowbelts would be most likely to see the best chances for
precipitation. It does look like temperatures overall will trend
colder during this time period and 850mb temperatures are progged to
cool to the -6C to -8C range. Models begin to differ beyond Friday
afternoon, with the EC placing a ridge over the area while the GFS
has a trough over the area Saturday into Sunday, before both
aligning with a slight troughing pattern form Monday. At this point
will stick with a consensus of the models for the late part of the
extended.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1235 AM EST MON NOV 28 2016
IFR/low-end MVFR conditions to prevail at KSAW and KCMX through the
forecast with KSAW and KIWD experiencing some LIFR ceilings at times
during the daylight hours, but especially once the sun sets Monday
evening. Areas of rain continues to spread toward the region and
will persist through Monday evening as a very moist SE flow
continues. Winds to be gusty through the daylight hours with the
highest gusts reaching near 28 knots at KCMX due to channelized flow
there. Gusts to reach into the 20-25 knot range at KSAW and KIWD
during the day before diminishing in the late afternoon.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 356 PM EST SUN NOV 27 2016
High pressure over the ern Great Lakes will shift to the east
tonight as low pressure deepens across the northern plains into the
upper midwest. This will result in a tight pressure gradient
developing across the northern Great Lakes creating gales overnight.
Gales to 40kt are expected across all of Lake Superior spreading
west to east, but the gradient will slacken earliest across the far
west. Further east the gradient will remain tight, with gales
lingering through Mon night. The low pressure system will linger
over the upper midwest Tuesday into Wednesday. However the pressure
gradient is not expected to be as tight and allow winds to diminish
below 25kt by Tuesday evening. Northerly winds to around 25 knots may
develop Thursday as the slow moving low moves to the east of Lake
Superior into Quebec.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Warning until 10 AM EST Tuesday for LSZ249>251-266-267.
Gale Warning until 8 AM EST /7 AM CST/ this morning for LSZ162.
Gale Warning until 4 AM EST Tuesday for LSZ243-244-264.
Gale Warning until midnight EST /11 PM CST/ tonight for
LSZ240>242-245>248-263-265.
Lake Michigan...
Gale Warning until 4 AM EST Tuesday for LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...RJT
MARINE...JLB
Area Forecast Discussion
National Weather Service Pocatello ID
212 AM MST Mon Nov 28 2016
.SHORT TERM...Today through Tuesday night. The story the day for
many will be snow and wind. The focus for snow continues to be
across portions of the central mountains, eastern and southern
highlands plus along the interstate corridor from Idaho Falls
through Burley. The main band will swing through during the early
to mid morning hours, with winds either staying pretty gusty or
increasing along/behind it depending on location. While there may
not be a lot of snow with this band, the wind and timing during
the morning drive will make it a bit tricky in many locations. By
late morning and afternoon, many areas will see a decrease in
widespread snow and things becoming more showery. The EXCEPTION
will be across the southern/southeastern highlands and along the
interstate corridor from Idaho Falls to Coldwater. Snow will
continue across those highlands areas especially where upslope is
favored in northwest flow. The higher resolution models like the
NAM and HRRR indicate a convergence band combined with upslope
will keep some snow going across portions of the Snake Plain. The
strongest winds still look to be from Pocatello westward and south
into the south central highlands. Winds in these areas will peak
between 25-35mph sustained with gusts of 40+mph. They will be
higher off the valley floor south of the Snake River, with some
places briefly exceeding 60mph based on the latest forecast.
Headlines will remain in place although we may be able to adjust
some timing during the day based on how things progress. Based on
how much snow falls across the Magic Valley, blowing snow may not
be an issue and the impacts end up being purely based on wind and
not blowing snow. Snow amounts will generally be 1-2 inches for
the Upper Snake Highlands and central mountains. For the Snake
Plain, expect up to 2 inches along the travel corridor with
locally higher amounts on the benches. For the southern and
eastern highlands, look for 1-3 inches down low and 3-6 inches at
mid and upper slopes. Locally higher amounts are possible.
Tonight, some showers will continue especially across the
southeast highlands. Through this evening, the models still point
to lingering snow from around Blackfoot to Coldwater associated
with the dying convergence band and upslope. Winds will die down
but still remain a bit gusty coming across portions of the central
mountains and the south central highlands.
Conditions will dry out more on Tuesday ahead of the next storm.
It will remain cold as we stay in northwest flow. Tuesday night,
it looks like we could see some fog and light snow/flurries across
portions of the Upper Snake Plain and Highlands. Keyes
.LONG TERM...Wednesday through Monday. Models in much better
agreement tonight. Upper ridge still expected to fold across the
region Wednesday though weak upslope could keep precip going in
northeast corner. Stronger shortwave drops through PacNW states into
Idaho Wednesday night into Thursday with snow spreading across the
region. Low appears to close off somewhere over Idaho Thursday
though there are still minor differences in location. Low drops
through four corners area Friday with next ridge folding over Idaho.
Moist northwest flow sets up with Friday night through Sunday
though models keep moisture spread through panhandle into MT. Have
kept weak pops over northern zones and across eastern highlands.
Stronger feature drops into Idaho Monday with ECMWF stronger than
GFS and further south with precipitation. Opted for blend with
increased precip chances most areas. DMH
&&
.AVIATION...Precipitation gradually filling in across the region
this morning though northwest flow aloft keeping most portions of
Snake Plain dry so far. Expect cigs/vis to lower to MVFR as snow
begins with occasional IFR in heaviest bands. Conditions improve to
mainly scattered MVFR snow showers this afternoon. Winds remain
strong through the day with Snake Plain terminals KPIH/KBYI
sustained around 25kts. Depending on how much snow accumulates
early, this could limit visibilities this afternoon in BLSN.
Gradient turns north late today with winds decreasing during the
evening. Isolated showers could continue overnight at terminals but
overall conditions should improve to VFR with occasional MVFR. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM MST this evening for IDZ017-
020>025.
&&
$$
Area Forecast Discussion
National Weather Service Portland Oregon
903 PM PST Sun Nov 27 2016
.SYNOPSIS...A strong cold front moved onshore from the northwest into
southwest Washington and northwest Oregon late this afternoon and
evening and will move out of the forecast area overnight tonight.
Gusty winds and fairly heavy rains with snow in the mountains
accompany this strong cold front. Northwest onshore flow behind the
front will spread plenty of showers through the area later tonight
and on Monday, with heavy snow continuing in the Cascades. High
pressure will bring a short break from the wet weather later Monday
night and Tuesday, though some locally dense fog may form in the
valleys. The next system is likely to bring more valley rain and
mountain snow to the forecast area later Tuesday night and Wednesday.
&&
.SHORT TERM...Tonight through Wednesday...After getting some snow in
the Cascades Saturday night with 6-7 inches reported at Willamette
Pass, another strong cold front was moving across southwest
Washington and northwest Oregon this evening, being pushed along by a
strong northwest jet up around 150 kt. The front began moving onshore
near Astoria around 5-6 pm and near Newport around 715 pm. Winds have
approached warning criteria at a couple of headland locations, with
widespread 40 to 50 mph gusts elsewhere along the coast. We are also
seeing some gusts to 35 mph in the Willamette Valley south of
Portland. The front will be through the Portland area around or just
after 8 pm, and past Eugene by around 9 pm.
The front has some heavy rain with it as it moves through, which will
translate to heavy snow in the Cascades, which combined with the wind
will lead to areas of blowing and drifting of snow, translating to
difficult travel conditions.
Moist northwest onshore flow will spread in behind the front, with
breezy conditions continuing, especially along the coast and in the
higher terrain. This will lead to showers over the area that will
continue through Monday and perhaps into early Monday evening, with
heavy orographic snows continuing in the Cascades. The current Winter
Storm Warning still seems reasonable with 1 to 2 foot accumulations,
the passes on the lower end of the range.
An upper ridge will bring drying to the forecast area going through
Monday night and Tuesday, though the models suggest a few residual
showers are possible Monday night and Tuesday. The building ridge
could lead to some areas of fog later Monday night and Tuesday
morning.
The next decent front spreads more rain onto the coast Tuesday
evening with valley rain and Cascade snow over the inland areas
during the second half of Tuesday night. Plenty of showers will
continue during the day Wednesday with snow continuing in the
Cascades. Snow amounts could reach the 4 to 8 inch range Tuesday
night and Wednesday, though a brief bump up in the snow level at the
beginning of this event might lower those numbers a touch. Tolleson
.LONG TERM...No Changes. Previous discussion follows...
Wednesday night through Sunday...Shower chances - in the form of
valley rain and Cascade snow, with snow levels remaining around 3,000
feet - continue Wednesday night through early Thursday. Heights then
begin to rise later Thursday as an upper ridge builds into the
Pacific NW. Some model differences remain for late Thursday and early
Friday with both the position of the ridge and the strength of a
system riding over the top of the ridge, but regardless, generally
drier conditions can be expected in between systems. Maintained
slight chance PoPs for the northern and northwestern portions of the
forecast area through this time. Flow aloft begins to become zonal by
early in the weekend as the next disturbance approaches the area, but
still some uncertainty as to where this will track across the region.
Expect showers to then persist through Sunday, when a stronger front
will push into the Pacific NW by late in the day, bringing sharply
lowering snow levels and another round of more significant and
widespread precipitation.
&&
.AVIATION...Cold front will likely have worked across the taf
terminals by the time 06z arrives. Cigs around 015 only lasting a
short time behind the front with a fairly rapid improvement to
VFR thereafter. A showery pattern will continue into Mon, but
expect conditions will remain VFR during most of this time. Strong
westerly flow into the Cascades will bring heavier showers and
keep the mountains mostly obscured through Mon.
KPDX AND APPROACHES...VFR cigs will return shortly as the trailing
edge of the cold frontal rains move east. Showers under westerly
flow will likely prevail for the period. JBonk/Pyle
&&
.MARINE...Cold front crossed earlier this evening bringing a
solid period of gales. Trailing northwesterly winds are somewhat
disappointing at 20-25kt with gusts around 30 kt. Was tempted to
drop the gale warning but winds at buoy 36 have stayed around 30
kt with frequent gusts around 40 kt. Additionally, the HRRR and
other convective allowing short term models allude convective
gusts will also remain around 40 kt for at least the next several
hours. So, will leave the gale warning in place as planned for the
time being.
Winds remain breezy early Mon, but will gradually subside through
the day. Weak high pres will build over the waters later Mon and
Tue, bringing winds below 15 kt. Another front will move through
the waters Tue night. The fcst models suggest solid or high end
small craft advisory winds are likely with this front, with an
outside chance at gales. Weak high pres will bring more benign
conditions for the second half of the week.
Seas continue to run around 12-14 feet and didn`t see an
appreciable increase with the frontal passage. Have seen plenty of
indications seas will build as the dynamic fetch from a strong low
in the northern Gulf of Alaska sends a large swell train towards
our waters on a parallel track to the BC coast. Seas will
gradually build through the day. Buoy 46004, well offshore the
southern tip of Haida Gwaii, saw seas peak at 32 feet/14 seconds
earlier this evening. The standard wave decay model would bring
seas near 22 feet/16 seconds to the area Monday evening. This is a
couple feet above the 18z WW3 guidance. Have increase our NW swell
by a couple feet covering Monday afternoon with a gradual decay
through Tuesday afternoon. Would expect little overall impact on
the High Surf Advisory. /JBonk
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory from noon Monday to 1 AM PST Tuesday for
Central Oregon Coast-North Oregon Coast.
Winter Storm Warning until 6 PM PST Monday for Cascades in Lane
County-Northern Oregon Cascades.
WA...High Surf Advisory from noon Monday to 1 AM PST Tuesday for
South Washington Coast.
Winter Storm Warning until 6 PM PST Monday for South Washington
Cascades.
PZ...Gale Warning until 7 AM PST Monday for Coastal Waters from Cape
Shoalwater WA to Florence OR out 60 nm.
Small Craft Advisory for Rough Columbia River Bar until 10 AM
PST Tuesday.
&&
$$
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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...Corrected
National Weather Service Tampa Bay Ruskin FL
301 AM EST Mon Nov 28 2016
.SYNOPSIS...
08Z water vapor and H4 RAP analysis showing a complex upper level
pattern over North America early this morning. Simplifying the
longwave pattern shows strong jet energy arriving over the
Oregon/northern California coast into the backside/base of
troughing covering the inter-mountain west and mid-section of the
country. Southern stream energy is also lifting across northern
Mexico into the base of this trough and then advancing into the TN
valley over-top weak longwave ridging that is providing generally
fair and warm conditions to the Florida peninsula. This ridge
will be the dominant force in our weather for the next 24-48
hours.
At the surface...1020+mb ridge centered over the mid-atlantic
states will shift eastward today and tonight over the Atlantic as
a cold front shift eastward from the central plains states toward
the Appalachians. Our local winds will veer from east to
southeast and eventually south by later tonight in response to
these mass-field changes.
Conditions are benign and seasonable across the region early this
morning...with temperatures generally in the 50s to lower 60s. A
few normally cooler spots north of the I-4 corridor may briefly
dip into the upper 40s by dawn...but readings this low will not be
widespread.
&&
.SHORT TERM (Today through Tuesday)...
Upper ridging holds position over the FL peninsula today. Weak
large scale subsidence under the ridge above 700mb keeps the
majority of the troposphere dry. Below 700mb...things are a bit
more complex. Veering low level winds to the southeast will
introduce a swath of WAA and weak isentropic upglide along the
295-305K surfaces beginning this morning and lingering into the
afternoon hours. While shallow...RUC/NAM/GFS all show a gradual
southeast to northwest moistening of the lowest 10KFT of the trop
due to this upglide. So...would at the very least anticipate the
development of a BKN cu/statocu deck as we advance into the late
morning and especially afternoon hours. Would also anticipate some
sct sprinkles to be around this afternoon...moving quickly south
to north. Once again...the moisture is relatively shallow...and so
sprinkles/light showers are all we are going to see. However...it
is worth mentioning that a few raindrops can not be ruled out.
Would say..most spots do not even measure...but a few hundredths
would not surprise me in spots either. Have a swath of low 20-30%
Pops with very low QPF this afternoon to account for this
potential. Otherwise...partly to mostly cloudy skies by this
afternoon with highs in the mid/upper 70s north and around 80
central and southern zones.
Few sprinkles fade away this evening as the overall WAA/upglide
shifts northward and we loose diurnal heating. The overnight
forecast will feature partly cloudy skies...a light southeast to
south breeze...and warm temperatures for the the end of November.
Most spots tonight are unlikely to drop out of the 60s. SREF and
statistical guidance suggesting some fog potential late at
night...most likely in response to the boundary layer moisture
and ridging aloft. However...gradient may stay just tight enough
to keep boundary layer at least partially mixed and prevent
significant areas of fog. Will add patchy fog to the grids after
06Z tonight...but allow day shift time to re-evaluate before going
to aggressive on the low visibility.
Tuesday shaping up to be a rather warm and seasonably humid day.
Warm low levels (14-15C at 850mb) and decent gradient to support
diurnal mixing should allow temps to easily reach the lower 80s
for a large portion of the region. Some spots reaching the middle
80s certainly possible from the I-4 corridor southward if we can
get sufficient insolation. Southerly flow may even shift southwest
at the coast for a time in response to the strong terrestrial
heating. This onshore component off the relatively "cooler" shelf
waters of the eastern Gulf should limit the diurnal heating at the
immediate coast...and hold beach temps in the 70s. The
WAA/upglide component we have today is not forecast to be repeated
tomorrow...and will keep all shower/sprinkle mention out of the
forecast for this cycle.
&&
.LONG TERM (Wednesday through next Monday)...
A highly amplified pattern continues over the CONUS. A strong
upper level low sits over the Midwestern states with a positively
tilted trough extending southwest through New Mexico. This is
supporting a major storm system moving through the Great Lakes
region and the eastern half of the U.S. Upper level ridging
extends northeast over the western Atlantic from an upper high
located over Cuba. This ridge will prevent any significant
movement of the upper trough through mid week. The trough will
slowly progress eastward on Thursday as the ridging weakens and
moves east of the Bahamas. By the end of the week and into next
weekend, a more zonal pattern sets up over the southeast U.S.
On the surface, the high pressure that had been sitting over the
eastern U.S. has slipped eastward and it now located near Bermuda.
This will keep dry conditions and a southeast wind flow over the
area through mid week. Over the central U.S., the upper parent low
pressure system is located over Minnesota with another low pressure
center developing over Lake Superior. The associated frontal
boundary extends south along the Appalachian Mountain chain. The low
will be located over Nova Scotia by Wednesday morning with the front
extending along the eastern seaboard. Another low pressure system
develops over Mississippi and extends a cold front into the Gulf of
Mexico. This is the system that will give us our highest rain
chances through the period. This system moves rapidly to the
northeast and will trail a cold front across the area beginning late
Wednesday. The front will push completely south of the area by early
Friday morning. In the wake of this front, cooler and drier air will
filter into the area through next weekend as high pressure builds to
the north. By late Sunday next week, models are hinting at another
low developing along the northern Gulf and moving eastward.
As for weather during the period, dry conditions can be expected
through mid week. The frontal boundary moving through the area late
Wednesday into Thursday will bring us our highest chances of rain in
the period with 40-50 POPs over the northern coastal waters/Nature
Coast and 20-30 POPs from Tampa Bay southward. The front exits the
area by early Friday morning with clearing conditions expected
through the weekend. Late Sunday into Monday, the developing low
over the northern Gulf will bring us a second round of rainfall with
30-40 POPs region wide. Daytime highs will be at or above normal
through Thursday, then dropping down 3-5 degrees below normal on
Friday and Saturday, then warming back up once again to average on
Sunday and into early next week.
&&
.AVIATION (28/09 through 29/06Z)...
No significant aviation concerns expected across west-central and
southwest Florida through the TAF period. Potential for brief MVFR
patchy fog toward dawn at KLAL/KPGD...otherwise VFR prevailing
through Monday with a sct-bkn cumulus field (bases at or above
4KFT). Widely sct light and brief showers/sprinkles possible after
18Z...but no associated restrictions. light east winds becoming
moderate southeast (9-12kts...gusts 15-18kts) by late morning.
&&
.MARINE...
High pressure over the eastern states shifts into the Atlantic
through Tuesday as a cold front advances eastward through the
Appalachians. In response...winds over the eastern Gulf of Mexico
will shift from east to southeast and then south through Tuesday.
Periods of cautionary level winds between 15 and 20 knots can be
expected away from the coast through tonight. Another period of
cautionary winds is forecast for Tuesday night into Wednesday away
from the coast.
&&
.FIRE WEATHER...
No significant fire weather concerns expected through the middle
of the week across west-central and southwest Florida. Low level
moisture will be on a steady increase into Tuesday...preventing
any areas of critical low relative humidity. Wind profiles will
support elevated dispersion indices Today and Tuesday. Widely
scattered sprinkles/light showers are expected across the region
this afternoon...however the potential for a wetting rainfall is
low for most areas.
&&
.Preliminary Point Temps/PoPs...
TPA 79 66 81 69 / 30 20 0 10
FMY 81 65 83 67 / 30 20 10 10
GIF 79 63 83 66 / 30 20 10 10
SRQ 79 66 78 67 / 20 10 10 10
BKV 80 63 82 63 / 30 20 0 10
SPG 77 66 79 68 / 20 10 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...Beach Hazards Statement through this evening for Coastal
Sarasota.
Gulf waters...None.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX..Mroczka
MID TERM/LONG TERM/DECISION SUPPORT...Wynn
Area Forecast Discussion
National Weather Service Albany NY
547 PM EST Mon Nov 28 2016
.SYNOPSIS...
An active period of weather for the region as a couple of storms
are set to impact the region. While most of the precipitation will
fall as rain, a period of wintry type weather is possible across
the Adirondack Region and Southern Vermont overnight into early
Tuesday morning. In the wake of these storm systems, brisk and
cooler weather is expected for the end of this week.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 545 PM EST...Skies remain mainly clear across the eastern
half of the forecast area with high clouds starting to stream in
across western areas. Temperatures have fallen quickly early this
evening with the lack of cloud cover and should continue to fall
quickly for the next few hours before leveling off. A deep cyclone
over the center of the nation remains quasi- stationary with an
impressive plume of moisture racing from Baja California into the
mid and lower Mississippi River Valley. The low level jet
increases quickly toward sunrise close to 50kts with strong
isentropic lift and impressive omega signatures. Question is just
how low temperatures will get before the cloud coverage arrives
and temperatures slowly moderate as the precipitation arrives. At
this time, low level ageostrophic flow per the latest RAP remains
and increases in magnitudes from the northeast. This would place
portions of the Adirondacks, Lake George Region and southern
Vermont (mainly eastern Windham County) under the threat of
keeping the low level sub-freezing temperatures in place for a
period of time as strong warm advection is underway. Per
collaboration with other WFOS, we will withhold any headlines as
the period of wintry type precipitation should be less than 3
hours which we can issue a SPS.
Otherwise, clouds increase and PoPs increase from southwest to
northeast well after midnight with overnight lows mainly into the
30s with 20s to the north of I90. Those temperatures slowly rise
after 09z toward sunrise as strength of low level warm advection
increases.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Impressive low level jet along with warm/moist advection will be
across the region through most of the day. So a rainy and breezy
day (mainly across the terrain) setting up across the region. As
is the case in these low level jet warm advection regimes, its
difficult to mix down the higher momentum air aloft. A possible
exception would be portions of the Taconics, Berkshires and
Catskills. Winds may back just enough to result in a bit more
magnitudes for these areas as we will continue to watch if those
backing of the winds materializes. South to southeast winds of 10
to 20 mph with some gusts in the 30-40 mph are possible. The 12Z
GEFS remains with southerly wind anomalies /+v-component/ of 1 to
3 standard deviations above normal with PWAT anomalies a couple
standard deviations above normal in the late morning into the
early pm. In addition, did include the slight chance mention of
thunder along the I84 corridor which is in coordination from SPC
and OKX. The showalter values drop close to +1C and per lightning
activity upstream, showalter values of +2C and lower is where
lightning activity was most prevalent. Highs Tuesday climb mainly
into the 40s with some lower 50s south of the Capital District.
Tuesday Night...A lull in the action is expected as a micro-
ridge or bubble-sfc high, but it will be short-lived as another
short-wave will be ejecting along the E/SE flank of the H500
positively tilted long-wave trough from the Southeast and TN
Valley. As a few breaks in the clouds are expected and very moist
low levels, fog could be an issue as we will add patchy fog to the
forecast/grids. The clouds will thicken again overnight from the
south and west towards sunrise. Lows will be on the mild side with
mid 30s to mid 40s.
Wed-Wed night....More rain on the way. Deep transport of moisture
from the Gulf of Mexico, as low pressure approaches from the Ohio
Valley during the morning. Strong/Impressive isentropic lift
increases ahead of the cyclone and warm front again. PWATS surge
back to 2-3 standard deviations above normal. In the area of upper
level diffluence aloft, expect periods of moderate to heavy rain
to overspread the region by the afternoon into the evening period,
especially along the enhanced FGEN band expected to lift northward
across the region. Likely to categorical pops were used again
through Wednesday into the early evening hours. An additional
two-thirds to around 1.25 inches of rainfall is expected and well
coordinated. These rain amounts should help out the drought
conditions across the region (see hydro section for additional
details). Above normal temps are likely in the mild air mass with
mid 40s to mid 50s again...and lows mid and upper 40s south and
east of the Capital Region...and mid 30s to lower 40s from Capital
District north and west.
Triple point per the NCEP model suite and ECMWF is expected to
move across the mid-Hudson Valley into northwest CT Wednesday
evening. There could be another brief period of thunder potential
for the southern portions of the region which we may add in future
forecast updates. Precipitation should taper back from southwest
to northeast as dry slot advances quickly into the region. Once
again, southeast low level jet may enhance wind gusts into the
Catskills, Taconics and Berkshires and southern Greens early
Wednesday evening.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
The long term period starts out with a departing surface low off the
New England coast. A second low over eastern Canada will be
responsible for some wrap around moisture across the northern
mountains on Thursday along with some lake enhanced pcpn downwind of
Lake Ontario. The remainder of the forecast area should be dry.
Highs on Thursday will be in the Upper 30s to lower 50s.
Thursday night through Friday night...Another weak clipper system
moves across southern Canada bringing more light pcpn to the region
with some lake enhanced pcpn continuing downwind of Lake Ontario
through Friday. Lows Thursday night are expected to range from the
upper 20s to mid 30s with highs on Friday in the mid 30s to upper
40s and lows Friday night in the mid 20s to lower 30s.
Saturday through Sunday...A mainly dry forecast is expected as high
pressure ridges into the region. There still may be a little lake
effect activity into northern Herkimer county but that should be the
extent of it. Highs on Saturday and Sunday will be in the upper 20s
to mid 40s with lows Saturday night mainly in the 20s.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR conditions with sct high level cirrus clouds expected through
the afternoon as high pressure moves eastward across the region.
Clouds will thicken overnight and ceilings will gradually lower
after midnight.
Expect VFR conditions to persist until around 12Z Tomorrow, with
light rain beginning between 09Z-12Z. Light to moderate rain
during the morning combined with a moist southeast flow off the
Atlantic Ocean should allow for MVFR/IFR ceilings and visibilities
by late morning.
Surface winds will be variable around 5 kt or less through 12Z
tomorrow before increasing from the southeast to 5 to 10 kts with
gusts to 20kts later in the morning.
Outlook...
Tuesday Night: Low Operational Impact. Slight Chance of SHRA...FG.
Wednesday: High Operational Impact. Likely RA.
Wednesday Night: High Operational Impact. Breezy Definite SHRA...RA.
Thursday: Slight Chance of SHRA.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: Low Operational Impact. Slight Chance of SHRA.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
Wet conditions will prevail through the middle of the week.
&&
.HYDROLOGY...
No widespread hydro problems are expected the next 5-7 days
ending Friday.
Diurnal snow melt will continue over the higher terrain through
the mid week period. A widespread rainfall along with milder
temperatures are expected Tuesday into Thursday with a series of
disturbances impacting the region.
The first round of rainfall with a brief light mix of sleet snow
and ice north of the Mohawk Valley and Capital Region occurs
Tuesday morning, then all rain by late morning. Rainfall amounts
of a third of an inch to three quarters of an inch are expected
with up to one inch south of Albany.
The second round of rain comes late Wednesday morning into
Thursday. Total rainfall may be three quarters of an inch to an
inch and a quarter. The runoff from the rainfall combined with
some higher elevation snowmelt may cause some elevated flows, but
a widespread flood potential is not expected at this time.
It has been quite dry in past months but vegetation and trees are not
soaking up water this time of year. MMEFS and latest NERFC
outlooks suggests no problems at this time but some areas just
west of our area are showing the potential to perhaps get solidly
into action stage (mainly southern tier of NY). Overall, the rain
should help the drought conditions across the ALY HSA.
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...BGM
NEAR TERM...BGM/11
SHORT TERM...BGM
LONG TERM...JPV
AVIATION...SND
FIRE WEATHER...BGM/Wasula
HYDROLOGY...BGM/Wasula
Area Forecast Discussion
National Weather Service Binghamton NY
557 PM EST Mon Nov 28 2016
.SYNOPSIS...
A storm system will spread rain showers and mild temperatures into
NY and PA late tonight and Tuesday. A second storm system will
ride up the east coast on Wednesday, bringing another round of
rain.
&&
.NEAR TERM /THROUGH TUESDAY/...
555 PM Update...
The timing of rain tonight looks good and so do our minimum temps.
The latest RUC has the 850 MB 0C line up across northeast, well
removed from our area. Despite some cooling in the mid levels
thanks to evaporational cooling, strong warm air advection
tonight will be enough to keep the precip all in the liquid form.
We only had a few tenths of snow in the far east but that is the
only minor change I made, removing it from our forecast. The
previous AFD is below.
210 PM update...
A large storm system spinning over Minnesota and Wisconsin will
pull moisture into NY and PA this evening. The model trend
continues to point toward slower solutions, and our current
forecast does not bring precipitation into our far western
counties until after 2z.
The slower solution also means the low stratus won`t reach our FA
until late, so minimums will be a tad lower than previously
forecast. Temperatures are forecast to rise after 6z.
With slightly cooler temperatures entrenched over the east, it is
possible the front edge of the precipitation will contain a wet
snow-rain mix, especially east of I-81. No more than a tenth of an
inch of snow accumulation is anticipated.
Precipitation will exit the I-81 corridor during the late-morning
or early-afternoon hours. Temperatures will max out in the lower
or middle 50s Tuesday.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Main concerns in the short term remain focused around the potential
for fog Tue night and Wed morning...the next batch of rain expected
during the day Wednesday...and lingering light rain showers Wed
night through the day Thursday.
Exiting system to the east will leave in its wake a weak area of
high pressure along with a brief period of ridging aloft to help
keep conditions relatively dry Tue night and Wed morning. The
potential for rain will be low during this time, but the threat for
fog will increase under this largely suppressed and nearly saturated
air mass. With the recent rain Tuesday over much of the area and waa
aloft, conditions will be favorable for patchy fog through early
Wednesday.
The ridge will be amplifying in response to a deepening trough of
low pressure cutting through the Great Lakes. There will also be
another robust supply of deep layer moisture advecting nwd along the
east coast ahead of this system, which will supply the necessary
ingredients for widespread rain, with locally heavy rain possible
from the Poconos into the srn Catskills. Large-scale dynamics
combined with a relatively strong baroclinic zone along the trailing
cold front will provide the lift needed to produce rain across the
region. PWATs close to 1 inch in ne PA will increase the potential
for around 1-2 inches of rain in this area. Locations further to the
west and north will likely see around 0.5 to 1 inch through Wed
night.
Upper low to the north will remain nearly stationary, or slow
moving, from srn Ontario into Quebec on Thursday. This upper level
support combined with weak caa in the mid levels, the potential
for scattered rain showers will exist through the day.
Morning low temperatures Wed will bottom out in the mid 40s.
Afternoon highs on Wed will rise comfortably into the mid and upper
50s. Low 40s expected again Wed night, with not much warming during
the day Thur...only into the mid and upper 40s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The extended period will remain quite active Thur night through
the weekend with high pressure over the deep south and a series of
upper waves tracking ewd through the Great Lakes into the NE under
a cool air mass regime. These waves will interact weakly with Lake
Ontario to produce periodic daytime/lower elevation rain showers,
and high elevation rain and/or snow showers. The showers will
likely become all snow by late Saturday and Sunday as the colder
air mass arrives.
Lows Thursday night will fall into the lower/mid 30s, and rise into
the upper 30s and lower 40s Friday afternoon. A bit colder Friday
night into the upper 20s/lower 30s. Temps will remain fairly steady
into the weekend with highs in the upper 30s and lows in the upper
20s.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
After a quiet early Monday evening, rain will spread into the
terminals late overnight, with MVFR restrictions developing toward
morning across much of the region.
IFR ceilings are likely to develop at KBGM before sunrise, with
the possibility for isolated IFR conditions at KAVP and KITH.
OUTLOOK...
Tuesday night-Thursday...Restrictions expected from periods of
rain.
Friday...Restrictions possible in rain/snow showers.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP/Heden
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...DJP
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
311 PM EST Mon Nov 28 2016
.DISCUSSION...
Lead batch of showers with initial moisture surge this morning
shriveled up and dissipated, as there was a lot of dry air in the
low levels to overcome, as 12z dtx sounding checked in with a 44 C
dew pt depression at 850 mb. Plenty of moisture over the Western
Ohio Valley however, as ILX sounding indicated a 7 C dew pt at 850
mb. Should be no problem to generate widespread showers this
evening/tonight as upper wave/cold pool (-26 C at 500 mb) ejecting
out of the southern Plains will slide into Southern Lower Michigan
by morning. Excellent dynamics/negatively tilted trough axis,
coupled with modest instability (sfc-850 MB going slightly negative)
supports isolated mention of thunderstorms, as thunderstorms have
also been reported upstream over Illinois, although the steep
level lapse rate (8 C/KM) arrive toward 12z, and that is
associated with the mid level dry slot, and it is likely
precipitation activity will have ended by then. Ridiculously
strong low level wind shear, as 0-1 KM bulk shear of 50+ knots
lifts through overnight, drawing concern for damaging winds and
and even non-zero tornado threat (see 17z HRRR STP fields 3-7 AM),
but near surface environment likely too stable to allow this to
happen, along with the overall limited cape/instability.
Good drying/subsidence to take place tomorrow with PW values
slipping back below half an inch, although low level moisture (2-3
kft)/clouds will likely take some time to scour out, which could
impact maxes slightly, otherwise 925 mb temps around 10 C (per 12z
nam) suggests maxes approaching 60 degrees.
Weak wave/850-700 mb Theta-E to lift through Tuesday evening, and
mid level lapse rates appear steep enough to possibility generate a
few high based showers. Despite the near zero showalter index
progged, left mention of thunder out, as soundings still indicated a
lot of dry air down low and significant cap.
Massive Upper Level Low/Trough centered over Red River Valley
will slowly wobble off to the East-Southeast, translating through
Great Lakes Region during Wednesday-Thursday Time Frame. Upper
level PV train/trough axis over Four Corners region tomorrow,
tracking through Ohio Valley on Wednesday, with cyclogensis taking
place over Eastern Ohio Valley, into the Eastern Great Lakes by
Wednesday Evening. Looks reasonable shot of rain shield clipping
southeast Michigan in this time frame, per 12z Euro.
The beginning of December will start off with longwave troughing
over the region through the end of the week before ridging builds
back in. Periods of showers will still be possible as the low
pressure system continues to push off towards the New England area.
Drier conditions come back for the the majority of the weekend
before more unsettled weather moves back in by the end of the
weekend. Temperatures will remain consistent through the extended
period with highs hovering around 40 degrees and lows around 30
degrees.
&&
.MARINE...
Southeast winds will continue to increase into tonight as a warm
front approaches from the south. This will lead to a period of gale
force winds throughout the Lake Huron basin, as well as the Michigan
waters of Lake Erie. Peak gusts during the overnight period will
climb to between 40 to 45 knots across northern and central sections
of Lake Huron. The long southeast fetch will also support extensive
wave growth, with waves potential peaking near 20 feet. Small Craft
Advisories will transition to Gale Warnings this evening. Winds and
waves are projected to improve Tuesday night into Wednesday as
direction shifts to the southwest and milder air and more stable
conditions overspread the region.
&&
.HYDROLOGY...
Rain will overspread the area late this afternoon and continue into
tonight as abundant gulf moisture lifts north into area in advance
of approaching warm front. This rain will come to an end early
Tuesday morning as the warm front progresses north of the region.
Total rainfall amounts of one half to three quarters of an inch are
expected across the region during this time frame. While this is an
above normal amount of rainfall for this time of year, flooding is
not anticipated.
&&
.PREV DISCUSSION...
Issued at 1250 PM EST Mon Nov 28 2016
AVIATION...
Light rain will already be overspreading area by 18z-19z with rain
increasing in coverage/intensity into the 00z-06z time frame before
tapering off 06z-09z. Ceilings will lower through MVFR to IFR during
peak intensity of event. Visibilities will drop as well and at least
sporadically reach IFR this evening. SE flow will persist in advance
of warm front into tonight with 50-60 knot southerly low level jet
producing LLWS. Surface flow will then veer to SSW with passage of
warm front 08z-10z with ceilings gradually lifting thereafter as
rain shifts north of the area.
For DTW...Ceilings will fall below 5000 feet this afternoon as rain
overspreads the terminal with MVFR ceilings to follow by late this
afternoon. Still anticipate IFR conditions this evening into the
overnight as widespread rain lifts through area north of encroaching
warm front. Conditions then improve late tonight into Tuesday with
the passage of this front.
//DTW Threshold Probabilities...
* High for ceilings AOB 5000 feet into Tuesday morning.
* Low for thunderstorms affecting terminal this evening (00-06z)
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Gale Warning from 7 PM this evening to 4 PM EST Tuesday FOR LHZ363-
421-422-441-462.
Gale Warning from 7 PM this evening to 10 AM EST Tuesday FOR LHZ361-
362-442-443-463-464.
Small Craft Advisory until 7 PM EST this evening FOR LHZ421-441>443.
Lake St Clair...Small Craft Advisory from 7 PM this evening to 10 AM EST Tuesday
FOR LCZ460.
Michigan waters of Lake Erie...Gale Warning from 7 PM this evening
to 7 AM EST Tuesday FOR LEZ444.
&&
$$
DISCUSSION...SF/SS
MARINE.......DG
HYDROLOGY....DG
AVIATION.....DG
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Northern Indiana
358 PM EST Mon Nov 28 2016
.SYNOPSIS...
Issued at 357 PM EST Mon Nov 28 2016
Widespread rain will persist into the overnight hours. While
breezy conditions will prevail tonight, an isolated stronger
shower or thunderstorm on the back edge of the area of rain may
produce wind gusts to 50 mph. Rainfall amounts of one half to one
inch are expected, causing ponding of water as well as minor river
rises in some areas. Highs temperatures for the day will occur
into this evening as rising temperatures are expected. Steady
temperatures overnight will climb further on Tuesday with highs
well into the 50s to near 60. More seasonable temperatures will
return for the second half of the week.
&&
.SHORT TERM...(This Evening through Tuesday)
Issued at 357 PM EST Mon Nov 28 2016
Deep low pressure over SE North Dakota was making its impacts felt
as far east as the Great Lakes where surge of anomalously moist
air was heading north into the region. Expect widespread rain to
take over the forecast area into this evening with average
rainfall amounts of 0.75 to nearly 1 inch. While this will cause
some local ponding as well as minor river rises, somewhat larger
concern looms in the 23Z to 05Z window as dry slot rapidly works
northeast into the area. HRRR has been steadfast in developing a
narrow line of strong showers/isolated storms on the back edge of
the rain. 0-1 km shear values in excess of 50 kts and 0-1 km
helicity values in excess of 500 m2/s2 would suggest a non zero
risk for isolated tornadoes. However, low level
inversion/stability may hold just enough to keep the threat at
bay. Strong wind fields aloft may be mixed down to bring several
reports of 40 to 50 mph winds with the line. A lot of uncertainty
with regards to the evolution and amount of inhibition at the
surface warrants adding thunder mention and patching up HWO to
reflect brief wind threat. Trends will be monitored into the
evening.
Otherwise...occluded front will quickly push through and bring any
rain to an end by Tuesday morning. Rising temperatures this
evening will steady out overnight and then climb further on
Tuesday with highs into the middle 50s to around 60, depending on
amount of sunshine.
&&
.LONG TERM...(Tuesday Night through Monday)
Issued at 357 PM EST Mon Nov 28 2016
Deep upper low will slowly drift east into Wednesday night,
forcing a cold front and a series of upper level disturbances
through the area. This and bringing an end to the above normal
temperatures expected into Wednesday. Not much moisture to work
with so precip chances will be limited but still worth a mention.
Upper low will center SE of James Bay and continue to send several
additional waves through the region into the weekend with
difficult to time chances for rain and/or snow. No major systems
expected at this point so only slight chc to chc pops warranted,
mainly in the north.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1217 PM EST Mon Nov 28 2016
Secondary surge of moisture to likely bring IFR met conditions
especially due to ceilings later this afternoon/evening. Timing
of dry slot after daybreak Tuesday to bring return to VFR
conditions for much of day/later part of forecast. Mention of low
level wind shear as low level jet surges into northeast Indiana
after 00 UTC.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...Gale Warning until 4 AM EST Tuesday for LMZ043-046.
&&
$$
SYNOPSIS...Fisher
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Murphy
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Area Forecast Discussion
National Weather Service Saint Louis MO
322 PM CST Mon Nov 28 2016
.SHORT TERM... (Through Late Tuesday Afternoon)
Issued at 322 PM CST Mon Nov 28 2016
Rainfall over the eastern 1/3 of the CWFA will be ending from west to
east this evening as the "cold" front passes and drier air filters
into the area. Clouds are likewise clearing from west to east, but
are not moving out quite as fast as expected. Latest satellite pics
show the clearing line probably getting from central Missouri to the
St. Louis Metro area by 03-04Z...and then east to our CWFA border by
07-08Z. The RAP seems to have a decent handle on the clearing...so
have used it as the basis for my cloud forecast tonight. South to
southwest flow tonight into Tuesday isn`t exactly a cold wind...so
only expecting lows in the 40s tonight. Additionally there
should be a decent amount of insolation on Tuesday to go along with
the southerly flow. MOS looks reasonable with highs well above
normal again in the upper 50s to mid 60s.
Carney
.LONG TERM... (Tuesday Night through Next Monday)
Issued at 322 PM CST Mon Nov 28 2016
(Wednesday through Friday)
Still expect Wednesday through Saturday to be mainly dry. Both the
GFS and ECMWF are in good agreement that the upper low that will be
over the Upper Midwest on Wednesday morning will lift northeastward
through the Great Lakes and not bring any precipitation to the area.
In the meantime, zonal upper flow will setup at least through Friday
before the ECWMF and GFS begin showing diverging solutions to the
forecast over the weekend.
With polar cold front staying well south of the area during the
period and 850mb temperature staying around -5C, GEFS mean temps
support temperatures staying around normal values.
(Saturday through next Monday)
There continues to be great uncertainty with the forecast over the
weekend into early next week as the the ECMWF and the GFS are
showing different solutions. The GFS/GFS ensemble has shown more
continuity with bringing a northern stream trough across the area
Saturday night and Sunday which would bring some light rain/snow to
the area. The ECMWF on the other hand has not shown as much run to
run consistency, with it bringing out a larger, colder system over
the weekend that would have the potential to produce more snow.
Given the consistency of the GFS, will lean more toward it`s
solution at this point. Temperatures will continue to be close to
normal during the period.
Britt
&&
.AVIATION... (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1145 AM CST Mon Nov 28 2016
A broad area of rain with MVFR and IFR conditions is affecting
much of southeast and east central Missouri as well as southwest
and south central Illinois. A few showers are also moving over
parts of north central and northeast Missouri. The lowest ceilings
and visibilities will likely continue to be associated with the
main area of rain this afternoon. Should see this rain move slowly
east...clearing eastern sections of the area out by KSLO by
00-01Z. Expect the MVFR deck to clear as well from west to east
through the afternoon and evening hours. VFR conditions with
south-southwest flow will prevail after the low clouds clear out.
SPECIFICS FOR KSTL:
Area of rain with primarily MVFR ceilings will continue to move
over the terminal this afternoon. There will likely be a few
breaks in the rain...but just to add a little extra complexity to
the forecast there are some IFR ceilings in the vicinity and
Lambert reported SCT009 this hour. Am covering the possibility for
an IFR ceiling with a TEMPO for now. Latest guidance shows the
rain ending at Lambert between 23-01Z this evening. Ceilings will clear
from the east by mid evening and VFR flight conditions are
expected to prevail thereafter.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
258 PM CST Mon Nov 28 2016
.DISCUSSION...
Currently...A potent shortwave is pushing through the Arklatex.
Diffluent flow across the region is helping to create tremendous
lift which is resulting in widespread heavy rain. Poor lapse rates
and little surface based instability is resulting in little if
any thunder for the time being. A 995 mb mesolow has developed just
NW of Memphis in the Delta. This feature has created a very strong
pressure gradient across the Delta from the low to the south into
NW Mississippi. Many places have reported gusts over 50 mph with
trees down. This feature is forecast to track east northeast
across West Tennessee and continue to enhance surface winds as it
does so. Winds will probably will not be quite as strong outside
of the flat Delta though. A wind advisory will continue for much
of West Tennessee and North Mississippi through 6 pm. Areas to
the west of the line of strongest radar echoes....just east of a
Dyersburg through Memphis to Tallahatchie county line...have seen
winds shift to the west and start to diminish. Will be cancelling
the wind advisory for areas west of this line with forecast
issuance.
Heavy rain could cause some flooding of low lying areas especially
with leaves clogging drains.
This afternoon into early this evening...As the shortwave
continues to approach there could be some intensification of the
activity as it move east. The mesolow could also advect some
higher dewpoints into North Mississippi. Part of the problem is
that the winds in advance of the line are SE and the dewpoints in
that source region are not terribly high, maybe upper 50s. As a
result confidence in severe weather is decreasing. The enhanced
risk has been pulled from the region while a slight risk remains
for much of West Tennessee and North Mississippi along and east of
the line. If any stronger updrafts can develop and tap the
stronger winds aloft then perhaps a few bowing segments are
possible...mainly over Northeast Mississippi through about 00z.
Otherwise the main story really has been the gradient winds
produced by the mesolow.
Remainder of tonight...Rain and any thunderstorms will quickly
exit this evening early this evening with skies clearing from the
west. Temps will cool into the upper 40s and lower 50s. Model
soundings are showing a strong inversion developing with a
saturated layer near the ground. Winds will drop off quite a bit
and skies will clear. This combined with a wet ground may produce
patchy fog.
Tuesday...The main upper trough remains to the west and the Mid-
South will be between systems. Mild southerly flow will result in
much above normal temperatures in the lower 70s with a good deal
of sunshine.
Tuesday night and Wednesday...The next shortwave rotates around
the main trough positioned over the central states. This feature
will fire up showers and thunderstorms along the old
boundary...from todays activity...just southeast of our area.
Those showers and thunderstorms will push north into at least part
of our area as a surface wave moves along the stalled boundary.
Northeast Mississippi stands the best chance of seeing showers and
thunderstorms with chances diminishing to the NW. A few storms
could be strong across Northeast Mississippi since some
instability is depicted across the area though the best chance for
severe weather will probably remain SE of our forecast area.
After the shortwave kicks east cooler and drier air start to push
in from the west.
Thursday and Friday...High pressure builds in with seasonably
cool weather. Highs in the 50s and lows in the 30s.
Saturday through Monday...Looks unsettled during this time frame.
The 12z ECMWF moves a significant system into the region this
weekend while GFS cut off an upper low over Mexico and then ejects
it early next week. Will look for some more consistency in future
runs to pinpoint rain chances but for now will go with chance pops
through the period.
SJM
&&
.AVIATION...
18Z TAFs
Primary aviation concern is low level non-convective wind shear
and surface wind speeds prior to arrival of TSRA. CKM and UTA
reported gusts in excess of 40KT earlier this morning, while post
TSRA winds in south central AR were slightly weaker at 30 to 40KT.
Regarding timing of TSRA into MEM, HRRR and RAP models have dialed
back timing just a bit, around 21Z.
Primary change with the 18Z TAFs was to include LIFR cigs and vsby
at most terminals for the late overnight. NAM Bufr and RAP soundings
both depicted a steep moist inversion developing below FL003 toward
12Z, with moisture-laden southerly winds off the deck lifting over
the shallow and cooler near-surface air. The stronger winds aloft
should mix down by midmorning, returning VFR.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...Wind Advisory until 6 PM CST this evening for Alcorn-Benton MS-
Calhoun-Chickasaw-Itawamba-Lafayette-Lee MS-Marshall-Monroe-
Panola-Pontotoc-Prentiss-Quitman-Tallahatchie-Tate-Tippah-
Tishomingo-Union-Yalobusha.
TN...Wind Advisory until 6 PM CST this evening for Benton TN-Carroll-
Chester-Crockett-Decatur-Fayette-Gibson-Hardeman-Hardin-
Haywood-Henderson-Henry-Madison-McNairy-Weakley.
&&
$$
Area Forecast Discussion
National Weather Service Marquette MI
415 PM EST Mon Nov 28 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 413 PM EST MON NOV 28 2016
WV imagery and RAP analysis indicated a broad mid/upper level trough
over the plains with a low centered over ern North Dakota. At the
surface, a 975 mb low was located over se ND with an occluded front
looping through ern MN into cntrl IA. The combination of a shortwave
trough and strong moisture advection supported a large area of rain
over WI that was quickly spreading to the north.
Tonight, the area of strong 700-300 mb qvector supporting the
upstream pcpn over WI is expected to lift to the nne through Upper
Michigan this evening and diminish across the cwa from sw to ne
between 06z-12z. So, the area of drizzle will give way to a steadier
moderate rain. With pwat values from 0.75-0.90 inch, QPF amounts in
the 0.50-1.00 inch will be common, especially over the southeast
half. Signficant drying will then move in late over the west and
south. Temps will remain well above normal with lows in the low to
mid 40s.
Tuesday, with the occluded front lifting to the north of the area
and qvector div and subsidence taking over, expect mainly dry
weather. Some wrap-around pcpn may sneak into the far west from nw
WI late. Otherwise, expect breezy southwest winds with temps slowly
falling into the upper 30 west. However, some sunshine over the
east half will help boost readings into the upper 40s.
.LONG TERM...(Tuesday night through Monday)
Issued at 343 PM EST MON NOV 28 2016
The low pressure system currently W of the region will weaken and
slowly meander across the area through Thu, with a couple other
waves possible coming down the back side of the system later in the
week. Colder air moves in late this week into Sat as an upper trough
moves out of NE Canada and into northern Ontario and Quebec. Early
next week is quite uncertain as models show differing solutions with
a system moving through the region.
Ptype will be driven largely by wet-bulb zero height, meaning more
snow during the night and over the higher terrain, and snow chances
will increase through the end of the week as the airmass gradually
cools. Best QPF through Sat looks to be on Thu when a shortwave
moves around the back side of the departing system and the SFC
trough swings through. However, mild SFC temps will keep precip
mixed or at least limit snowfall amounts with snow melting some as
it falls. Still some uncertainty there, but not a big concern at
this time.
Looking way out there, deterministic models are suggesting a much
colder trend beyond 10 days out, which is backed up with the CFS.
CFS also builds a large mass of very cold air across AK and the NW
Territories toward the end of Dec, which would signal a significant
pattern change.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1254 PM EST MON NOV 28 2016
Low level moisture streaming into the region ahead of a deep low
pressure and frontal system will maintain the low clouds into early
Tuesday. The downslope component with the se to s flow will keep
cigs mainly in the MVFR range at IWD and CMX. However, IFR/LIFR cigs
are expected at SAW. Light rain moving in again late today and
tonight along with fog will drop vsby into the IFR range. Drier air
moving into the area behind the occluded front as winds veer sw will
bring improving conditions by mid to late Tuesday morning.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 413 PM EST MON NOV 28 2016
Southeast gales in the tight pres gradient ahead of the deep ND low
will gradually shift off to the northeast tonight into early Tuesday.
The low pressure system will linger over the Upper Midwest Tuesday
into Wednesday. However the pressure gradient is not expected to be
as tight and should allow winds to diminish below 25kt by Tuesday
afternoon. Northerly winds to around 25 knots may develop Thursday
as the slow moving low moves to the east of Lake Superior into
Quebec.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Warning until 10 AM EST Tuesday for LSZ249>251-266-267.
Gale Warning until midnight EST /11 PM CST/ tonight for
LSZ240>242-245>248-263-265.
Gale Warning until 4 AM EST Tuesday for LSZ243-244-264.
Lake Michigan...
Gale Warning until 4 AM EST Tuesday for LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...Titus
AVIATION...JLB
MARINE...JLB
Area Forecast Discussion
National Weather Service Springfield MO
312 PM CST Mon Nov 28 2016
.SHORT TERM...(This evening through Tuesday)
Issued at 241 PM CST Mon Nov 28 2016
Initial shortwave rotating around the deep upper low over the
northern Plains was pushing through the area, with the main
precipitation shield now over the eastern Ozarks. Skies were
clearing across southeast Kansas and far western Missouri just
behind a surface boundary. This clearing will continue to progress
eastward through the late afternoon and early evening hours. 17Z
RAP model does show some instability over the eastern Ozarks
early this evening, so have kept lower end probabilities going.
Cannot rule out some small hail with any of the storms that may
develop.
Otherwise, upper low will continue to meander over the northern
Plains through Tuesday pushing a weak frontal boundary through
southeast Kansas and the Missouri Ozarks Tuesday afternoon. Front
will pass through dry, with just a wind shift to the west southwest.
temperatures will again be mild with highs in the upper 50s to lower
60s.
.LONG TERM...(Tuesday Night through Monday)
Issued at 241 PM CST Mon Nov 28 2016
Surface low over the upper Midwest will gradually shift into the
Great Lakes region through Thursday. The latest NAM and GFS show
some decent moisture wrapping around the back side of this system
and clipping central Missouri Wednesday night. However all precip
remains north of our area, so will keep this portion of the
forecast dry.
Next storm system to impact the CONUS will drop southward from the
northwest Pacific into the Desert Southwest by Friday/Saturday.
The system will tap into a deep moisture fetch over the eastern
Pacific and spread it northeastward into the central US by
Saturday night and Sunday. While it looks like the main
precipitation type will be rain with this system, temperatures
will be close enough to the freezing mark to possibly support
rain/snow mix, mainly late Saturday night and early Sunday. Will
be following the GFS solution for movement of this system as the
ECMWF continues to shift the system too quickly to the east.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1134 AM CST Mon Nov 28 2016
For the KSGF/KJLN/KBBG tafs: Shortwave trough rotating through the
region has pushed the rain shield to the east of the TAF sites with
a steady progression eastward expected this afternoon. Short term
models do generate a little instability this afternoon, but
mainly over the eastern Ozarks and cannot rule out a thunderstorm
or two. However not expecting any impact at the terminals at this
time. Back edge of clouds now near KJLN and will continue to push
eastward. Expect improving conditions through the afternoon and
into the evening with VFR flight conditions prevailing. Could
still see a few hours of MVFR ceilings early this afternoon
before drier air works its way in. Southerly winds should also
begin to subside bit by mid to late afternoon.
Enough mixing tonight is expected to preclude any mention of fog
at the terminals. Better chances for some MVFR visibilities will
reside over the far eastern Ozarks well east of the TAF sites.
Otherwise, VFR conditions expected.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Raberding
LONG TERM...Terry
AVIATION...Raberding
Area Forecast Discussion
National Weather Service San Diego CA
200 PM PST Mon Nov 28 2016
.SYNOPSIS...
An upper level disturbance moving southeastward through the Great
Basin this afternoon will bring strong onshore flow with gusty west
winds in the mountains and deserts and also bring a chance of
showers to San Diego County this afternoon and evening. Gusty
northeast winds will follow near the coastal foothills late tonight
into Tuesday...weakening Wednesday. It will be warmer Tuesday. A
cold low pressure system will develop late in the week over the
southwest United States and northwest Mexico with coolest weather
around Friday and possible strong gusty northeast winds Friday
through Saturday. Some daytime warming will occur over the weekend,
but the nights will remain chilly.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Skies were mostly cloudy this afternoon with a mix of low clouds and
high clouds. Windy conditions were occurring along east/southeast
mountain slopes and some passes. Burns Canyon, a local windy spot,
had a gust of 76 MPH around 8 AM, and White Water in San Gorgonio
Pass had a gust of 66 MPH around 10 AM. We are currently under a
northwest flow pattern with a 150-knot jet over Nevada and 700 MB
winds up to about 55 knots over our area. The HRRR and WRF has the
areas of strong winds on the east slopes and into the deserts
continuing through about 5 PM with fairly rapid weakening after
that. The wind advisory looks good for most locations as most gusts
will be in the 40s and 50s MPH, but local areas will be in the high
wind warning range.
The long-wave low pressure trough covers most of the western US with
a weak wave moving southeast on the back side over Nevada. There is
a chance of showers over San Diego County late this afternoon and
this evening due mostly to the over-the-water trajectories and
residual moisture. Precip amounts should mostly be under 1/10 inch.
We will transition to moderate offshore flow by Tuesday morning with
the strongest winds from just below Cajon Pass through west parts of
the Inland Empire to the Santa Ana Mountains. There will be a
mountain crest stable layer around 750 MB and a 6 MB MSLP gradient
from Las Vegas to San Diego. Local gusts could exceed 50 MPH. Weaker
winds will occur Wednesday morning. The offshore flow will bring
drier air and clear skies, and there will be some warming to almost
seasonal norms west of the mountains, with less warming over the
mountains/high deserts. In wind sheltered valleys Tuesday/Wednesday
night there could be local frost, though MOS guidance shows this
should not be widespread.
Looking ahead to late week, there is still a strong upper low moving
down from the north, and latest model guidance keeps moisture
sufficient for precip to our south, so we should stay dry. With the
upper low cutting possibly off to our SE, there will likely be tight
height gradients aloft and strong MSLP gradients at the surface,
though the 00Z and 12Z runs of the ECMWF have had the low weakening
and trending towards an open wave versus tighter closed low and also
further east than before. Especially if the stronger GFS solution
verifies, it could be quite windy over most of the region with the
wind direction from the northeast, with strongest winds in the
normal wind areas through/below passes/canyons. Humidities will be
quite low, but recent rains should reduce the fire weather threat.
Temperatures will decrease by Friday, especially over higher
terrain, but winds may keep nocturnal temperatures from falling too
low in the valleys at least Thu/Fri nights. With an East-Pacific
ridge following the upper low over the weekend, daytime temps should
be higher, with quite a few 70s at lower elevations, but dry air
could bring a chilly night to the valleys Saturday night as the
winds decrease.
&&
.AVIATION...
282100Z...Through 29/0900 UTC...clouds becoming BKN-OVC in the 2000-
7000 ft msl layer over and W of the mountains in San Diego county
and over the Riverside county mountains, with gradually increasing
-SHRA, mountain obscuration of coastal slopes, areas of vis 2-5 sm,
and local vis 1 sm due to SHRA. Elsewhere, mainly unrestricted vis
expected to continue with SCT-FEW clouds in the 2000-7000 ft msl
layer and SCT-BKN clouds AOA 20000 ft msl. 29/0900-1500 UTC...clouds
and any remaining -SHRA clearing out quickly, with mostly SKC and
unrestricted vis expected for all areas.
Through 29/0300 UTC...W winds in the mountains and deserts becoming
20-30 kt with gusts 40-50 kt, resulting in stg-svr
uddfs/llws/rotors. 29/0300-1500 UTC...W winds and associated
uddfs/llws over and east of mountains weakening, while NE winds
increasing to 15-25 kt with gusts 30-35 kt over coastal
slopes/foothills and through/below passes/canyons will create mod-
stg uddfs/llws over and W or SW of the mountains.
&&
.MARINE...
Reports from the San Clemente Basin buoy show that northwesterly
winds are currently at 16 kt gusting to 19 kt with 9.5 foot seas.
However, hi-res models show wind gusts increasing again in the outer
waters this afternoon and evening (up to around 25 kt) as another
upper level disturbance moves near the region. Thus, a Small Craft
Advisory continues for the outer waters through 10 pm tonight. Winds
and seas will diminish late tonight.
There is the possibility of strong offshore winds (N to NE) Friday
and/or Saturday which could result in hazardous sea conditions.
However, confidence is low at the moment.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 6 PM PST this evening for Apple and
Lucerne Valleys-Coachella Valley-Riverside County Mountains-
San Bernardino County Mountains-San Diego County Deserts-
San Diego County Mountains-San Gorgonio Pass Near Banning.
Wind Advisory from 10 PM this evening to 2 PM PST Tuesday for
Orange County Inland Areas-San Bernardino and Riverside
County Valleys-The Inland Empire.
PZ...Small Craft Advisory until 10 PM PST this evening for Waters
from San Mateo point to the Mexican Border Extending 30 to
60 nm out including San Clemente Island.
Small Craft Advisory until 4 AM PST early this morning for
Coastal Waters from San Mateo Point to the Mexican Border
and out to 30 nm.
&&
$$
PUBLIC...Maxwell
AVIATION/MARINE...Harrison