Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/04/16
Area Forecast Discussion
National Weather Service Albany NY
1047 PM EDT MON OCT 3 2016
.SYNOPSIS...
Some additional rain showers are possible into tonight
as an upper level low departs the region. Behind the departing
storm system, skies will clear out with comfortable temperatures on
Tuesday. High pressure will allow for dry weather through Friday,
with temperatures moderating above normal.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1030 PM EDT...Not much change from previous forecast.
Variable cloud coverage and some fog has developed where breaks
are more prevalent. Minor update based on current trends.
As of 730 PM EDT...H2O vapor loop reveals the upper low slowly
track east-southeast across southern New England. A few showers
remain but an overall diminishing trend is expected overnight with
the loss of the daytime heating. Latest HRRR still suggests with a
broad easterly flow around the periphery of the surface high
across Maine that lingering showers/sprinkles may impact our
western New England counties as we will retain the slight chance
to chance PoPs across these areas. Otherwise, per the enhance IR
Satellite imagery, several breaks in the overcast have been
observed but expectations are for additional low clouds/stratus
and patchy fog to evolve overnight.
Overnight lows will generally be in the 50s thanks to all the
clouds around. Some upper 40s are possible across the high
terrain.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Dry weather is expected through the entire short term period.
The upper level low that has been impacting the region will continue
to move eastward out to sea. At the same time, strong ridging over
the Great Lakes/Ohio Valley will translate eastward into the
Northeast behind the departing upper level low.
On Tuesday, surface high pressure will be situated over New England.
This should allow clouds to break for some sun, although it may
take until the afternoon hours for this to occur across the high
terrain of western New England and the Taconics. With 850 hpa
temps around 7-8 degrees C, high temps look to be in the 60s for
much of the region.
With mainly clear skies and light winds, temps should fall into
the 40s for Tuesday night. Some fog/mist will likely occur in the
typical areas, such as valleys and near bodies of water.
With high pressure directly over the area and warming temps aloft,
even warmer weather is expected for Wednesday into Thursday. There
should be plenty of sunshine each day thanks to the strong
subsidence in place. Max temps look to reach the upper 60s to near
70 on Wednesday for valley areas and into the low to mid 70s on
Thursday. It will continue to be seasonably cool with the good
radiational cooling for Wed night with lows in the 40s, but it
should remain warm enough to prevent any frost in the region.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Considerable uncertainty remains in the forecast as we continue to
watch the progress of `Matthew`. Please refer to the latest
outlooks and statements from the National Hurricane Center.
Through the long term, general model consensus is to build the ridge
along the mid-Atlantic and northeast corridors through the end of
this week. Meanwhile, a digging and somewhat progressive trough
moves through the Plains States, however, amplitude remains in
question (the ECMWF is rather flat and progressive with the GFS/GGEM
more amplified and a little slower).
We will follow the blended consensus with a dry and unseasonable
mild afternoon temperatures through at least Saturday morning with
seasonable overnight low temperatures with good nocturnal cooling.
We will increase clouds and PoPs later Saturday into Saturday night.
Depending on the track of `Matthew`, a period of rain is possible
Saturday night into Sunday morning.
Conditions should improve through Sunday as the aforementioned
trough upstream tracks through the region and what is left of
`Matthew` tracks off to our east or northeast. A shot of cold
advection is expected through Sunday into Sunday night where some
lake effect clouds/showers and maybe even some wet snow across the
higher terrain as H850 temperatures drop toward or just below 0C.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
While winds will generally be 5 knots or less from the northeast
or east direction, the main challenge tonight will be VIS and
CIGS. While conditions early this evening should remain VFR, there
is a wide range of CIGS from SKC into the mid-Hudson Valley to
BKN-OVC elsewhere. Trends are for more clouds to evolve as well as
low stratus/br/fg where more breaks occur. This will be reflected
in the TAFs with IFR probabilities increasing toward midnight.
VIS and CIG should improve within a couple of hours of sunrise
Tuesday for VFR conditions to prevail under a SCT-BKN clouds.
Outlook...
Tuesday Night-Friday: No Operational Impact. NO SIG WX.
Friday Night: Low Operational Impact. Slight Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.
&&
.FIRE WEATHER...
Some rain showers are possible this evening into tonight as an upper
level low departs the region. RH values will be near 100 percent
tonight with dew formation and some fog in spots as well. Winds will
be very light and variable.
Some breaks of sun are expected on Tuesday, but RH values will
generally remain above 60 percent through the day. East to southeast
winds will be around 5-10 mph. Dry weather is expected for Tuesday
through Friday.
&&
.HYDROLOGY...
The latest US Drought Monitor continues to show drought
conditions across much of the region. Precipitation departures
this calendar year have been 3 to 12 inches below normal, with the
greatest departures across southeastern parts of the HSA. As a
result, streamflow and ground water levels have been running below
normal.
As an upper level low departs the region, some additional rain
showers are possible this evening into tonight. While many
locations will stay dry, areas that see rainfall are only expected
to pick up to an additional quarter of an inch. This rainfall will
have little to no impact on area rivers and streams.
With high pressure returning to the region, dry weather is expected
tomorrow through Friday. This will allow rivers and streams to hold
steady through much of the week.
The next system to watch will be Hurricane Matthew, which is
currently in the Caribbean Sea. It is still too early to say if
this storm will have any impact on the HSA. If there was to be any
impact, it would be over the weekend.
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...Frugis
NEAR TERM...Frugis/BGM
SHORT TERM...Frugis
LONG TERM...BGM
AVIATION...IAA/BGM
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service La Crosse WI
631 PM CDT Mon Oct 3 2016
.UPDATE...
Issued at 631 PM CDT Mon Oct 3 2016
Have tweaked our cloud forecast into the evening and overnight in
the upward direction per satellite trends. Stratus is fairly
widespread at the moment into southwest WI and northern/eastern
IA, and this time of year, that`s not usually a good thing at the
sunset hour if you like clearer skies. Per RAP trends, suspect
strengthening southerly flow above 900mb will aid in transporting
that stratus northward through the night, perhaps filling in as
well as we continue to advect higher moisture through the 850mb
layer overnight. RAP has a pretty solid handle on the idea through
09Z, though confidence in how far north clouds will expand the
next few hours with some initially drier air in place remains
somewhat on the lower side. Will continue to follow trends through
the evening.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 221 PM CDT Mon Oct 3 2016
The upper level ridge extending from the Gulf of Mexico into the
the Great Lakes will continue to get pushed east into Tuesday as
the upper level low over western Wyoming lifts northeast onto the
High Plains. This low will then lift slowly north into Canada as
the first of several short wave troughs rotates underneath it.
This first wave is expected to come out of the central Rockies
Tuesday afternoon and move northeast to Lake Superior through
Wednesday morning. With this track, it should be able to produce
moderate pv advection in the 500-300 mb layer across the local
area Tuesday night. In the low levels, the warm air advection
ahead of the short wave trough should be able to produce 2 to 4
ubar/s of up glide on the 300K isentropic surface. The main axis
of moisture transport will be aimed well to the north of the area
ahead of the short wave trough and upper level low, but as the
whole system moves to the east, the convergent side of this
transport axis will work across the local area. A cold front will
move east with the short wave trough with a band of weak to a
times moderate frontogenesis in the 1000-500 mb layer. All this
forcing is expected to be enough to generate a line of shower and
storms along and ahead of the cold front for mainly Tuesday night.
The CAPE looks to be rather limited ahead of the front, but feel
the dynamics will be enough to overcome this and produce a fair
amount of thunder. Severe weather does not look to be a concern
because of the lack of CAPE though.
This system then moves quickly off the northeast with the rain
chances diminishing from west to east Wednesday morning with much
of Wednesday afternoon then looking to be dry. The next short wave
trough is then expected to rotate around the upper level low late
Wednesday night and just produces some weak pv advection in the
500-300 mb layer as it zips by to the northwest. This wave is not
expected to be able to produce much additional rain as it does not
track over the baroclinic zone, but may generate some showers
north of the front. Will carry a small rain chance late Wednesday
night across the southern sections for this.
The third short wave trough will come out of the Rockies and into
the Missouri River Valley Thursday. This will cause a surface low
to form along the the front and move into southwest Iowa or
northwest Missouri by late in the day. The front will start to
move back north as a warm front ahead of the surface low. The warm
air advection ahead of the surface could result in up to 2 ubar/s
of up glide on the 300K isentropic surface coming back over the
area. The instability north of the front looks to be rather
limited Thursday but both the 03.12Z NAM and GFS bring in at least
1000 J/Kg of MU CAPE across the south for a general shower and
storm threat. For now, will show rain chances across the entire
area Thursday with 30s in the north up to 60s across the south.
.LONG TERM...(Thursday night through Monday)
Issued at 221 PM CDT Mon Oct 3 2016
Models in fair agreement with a longwave trough extending from
Saskatchewan/Manitoba to the Four Corners region Thursday night. A
mid-level disturbance rotating around the base of the longwave
trough along with an attendant surface low will provide the focus
for precipitation across the area Thursday night. PWAT values of 1-
1.5 in. along with MUCAPE approaching 500 J/kg could pose a brief
heavy rain threat Thursday night. The surface low will move off
to the northeast Friday morning, leaving the region under a CAA
regime into the weekend. Highs will likely only top out in the 50s
Friday and Saturday. With overnight lows looking to drop into the
30s, the first frost of the season will be possible in some areas.
Both the GFS and ECMWF hint at ridging early next week, with a
weaker disturbance approaching the region on Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 631 PM CDT Mon Oct 3 2016
Lower stratus just south of LSE/RST has held firm through the
afternoon and per satellite trends now appears on track to arrive
much faster than earlier expected - generally in the 01-03Z time
frame for both sites. Ceilings are expected to remain VFR but
could briefly touch MVFR at RST later this evening. With
strengthening southerly flow, those lower clouds should gradually
work northward later tonight into Tuesday morning, leaving some
scattered cumulus and cirrus through midday as winds become gusty
from the south, with gusts perhaps briefly at high as 30 knots at
RST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
UPDATE...Lawrence
SHORT TERM...04
LONG TERM...MH
AVIATION...Lawrence
Area Forecast Discussion
National Weather Service Bismarck ND
943 PM CDT Mon Oct 3 2016
.UPDATE...
Issued at 937 PM CDT Mon Oct 3 2016
Main area of showers with some thunderstorms continue to lift
through south central into western North Dakota while a secondary
weaker line has formed further east over the James River Valley.
Storms will continue to lift northerly with a gradual eastward
drift. This is leading to some heavier rain concerns over northern
portions of the area. With that said, the threat for hail/wind has
diminished with the loss of instability and lack of deep layer
shear. For evening update have increased precipitation chances
pushing east through the area overnight with the system.
UPDATE Issued at 626 PM CDT Mon Oct 3 2016
Showers and thunderstorms continue to lift through many parts of
the area. Still some concern for severe storms over portions of
western North Dakota though chances of this remain slim due to the
lack of heating. Main concern at this point is shifting towards
the stronger storms moving in from western South Dakota. Will
keep a close eye on it this evening.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 121 PM CDT Mon Oct 3 2016
A severe thunderstorm threat highlights the short term period.
A negatively tilted upper level trough will lift northeast from
the central rockies into the northern high plains this
afternoon/evening and into southeast Montana tonight. This results
in cyclogenesis along the northern and central high plains and a
surface low lifting into southeast Montana this evening.
The latest iterations of short term models have become more
impressive with the low level shear over southwest into west
central ND from mid afternoon into this evening. 17 UTC iteration
of the RAP indicates the Significant tornado parameter and 0-1km
helicity maximized from 22-24 UTC Today over west central ND,
combined with low LCL values. High shear and low LCL values
continue into northwest and north central ND but surface heating
will be limited compared to the southwest/west central. The
thunderstorm threat also diminishes as you move east into south
central ND with the decrease in forcing associated with the strong
upper trough.
In addition to the severe threat this afternoon and evening, the
NAEFS ensemble situational awareness table is showing a strong
southerly transport of moisture into the region with an all time
maximum of precipitable water compared to climatology, over the
far northwest and north central. With the fast movement expected
with this dynamic system...will not issue any flood highlights
but will pass along. Heavy rain will be more of a threat as you
move into the deformation area over northwest and north central
ND.
After this evening...large dry slot swings across the area
bringing an end to the precipitation tonight
.LONG TERM...(Tuesday night through Monday)
Issued at 121 PM CDT Mon Oct 3 2016
Winds and rain or snow showers Tuesday through Wednesday then
Freezing temperatures highlight the long term forecast.
On Tuesday the surface and upper lows lift northward through
western ND and eastern MT with a significant dry slot over most of
the forecast area. There may be a little lingering showers early
Tuesday from the turtle mountains area into the James River
Valley. Then by the afternoon the wrap around moisture associated
with the upper low works its way into western Nd. This moisture
remains confined to mainly northwest ND Tuesday night. There is
enough cold air wrapping around the system to perhaps change
precipitation over to snow over the northwest late Tuesday night.
as the upper low tracks east...there may be a period of light snow
or rain and snow along the northern tier counties Wednesday
morning. The low finally exits the area late Wednesday bringing an
end to any light precipitation. If we do see any snow Tuesday
night through Wednesday, at this time it does not look like
anything more than a mix of rain and snow to a light dusting.
Wednesday night through Friday night will bring a stretch of
mainly dry but much colder weather. For the most part daytime
highs will be in the 40s and 50s with overnight lows in the mid
20s to mid 30s. We anticipate Freeze headline over the west
Wednesday night into Thursday morning. Then across most if not all
of western and central ND Thursday night and again Friday night. A
hard freeze will likely be experienced by most by the end of the
upcoming weekend. No highlights at this time but will continue a
mention within the HWO.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 626 PM CDT Mon Oct 3 2016
Showers and thunderstorms will continue to move through the area
tonight bringing scattered MVFR ceilings and visibilities, with
localized IFR in heavier precipitation. A few storms could be
severe over portions of western North Dakota for a brief period
early this evening. Quieter weather expected on Tuesday although
lower cigs could develop resulting in areas of MVFR conditions.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...JJS
Area Forecast Discussion
National Weather Service Charleston SC
1032 PM EDT Mon Oct 3 2016
.SYNOPSIS...
High pressure will build over the eastern United States through
mid week. Hurricane Matthew is expected to move north of the
Bahamas later this week and remain just off the Southeast U.S.
coast. However, there remains considerable uncertainty in the
strength and track of the storm. Refer to the latest advisory on
Matthew issued by the National Hurricane Center.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Overnight: A rather sharp N/NW to S/SE moisture gradient will
persist. Where deeper moisture persists, expect scattered/numerous
showers and occasional thunderstorms across far southern counties
and over adjacent coastal waters. Recent guidance, including the
00 UTC NAM, suggests that showers will spread north at least
along the southeast Georgia coast and perhaps even into SC coastal
locales as far north as Hilton Head Island. However, recent runs
of the HRRR depicting showers pushing onshore farther north along
the SC coast and deeper into the forecast area appear overdone
given the relatively dry air mass sampled by the 00Z KCHS
sounding.
Otherwise, under thick mid/high level clouds temps should bottom
out in the mid 60s inland and around 70F closer to the coast, even
mid 70s on the beaches.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Sfc high pressure will continue to build from the north/northeast
for the next couple days, while a stalled front remains well off the
Southeast Coast. Aloft, a mid/upper lvl low will gradually weaken
over the Northeast while Hurricane Matthew tracks north over Cuba
and the Bahamas into mid week. The forecast calls for slightly
cooler conditions as a north flow gradually becomes northeast.
However, precip chances should increase through the period, mainly
near coastal locations as moisture advects onshore. Given the setup,
have maintained a slight chance to chance of showers on Tuesday,
slight chances of precip on Wednesday, then increasing chances of
showers and thunderstorms on Thursday as the flow becomes more
directly onshore and PWATs approach 1.5 to 2.0 inches. Greatest
chances of precip are anticipated to be near coastal regions as we
head into late week.
Given increasing precip coverage and cloud cover, mid 80s temps on
Tuesday should trend cooler to upper 70s to lower 80s Wednesday and
Thursday. Overnight lows will likely range between the low/mid 60s
inland to upper 60s/lower 70s near the coast.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Uncertainty continues higher than normal this period, although there
seems to be more agreement amongst the latest model runs which track
Matthew closer to the Southeast U.S. coast late week into this
weekend. For now, we have followed the latest NHC/WPC forecast which
shows Matthew moving north from the Bahamas through late week,
remaining off the Southeast Georgia and just off the Southeast South
Carolina coast. Impacts will be largely dependent on the
track/intensity of Matthew and given the forecast uncertainty we
urge everyone to stay tuned to the latest forecasts. At the very
least, we will likely see breezy/showery conditions across the area,
especially near the coast, until Matthew moves northeast of the area
late week into the weekend.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
VFR through Tuesday. Showers/thunderstorms could impact KSAV
late tonight into Tuesday but potential remains too low to
mention within 00Z TAFs.
Extended Aviation Outlook: VFR conditions will generally prevail
through Tuesday outside brief showers and/or an isolated
thunderstorm that shift onshore. Flight restrictions due to low
clouds/showers along with breezy/gusty winds are possible Wednesday
through Friday, especially if tropical cyclone Matthew tracks close
to the Southeast U.S. coast late in the week.
&&
.MARINE...
Overnight: Ongoing forecasts remain on track. East to northeast
winds will continue with speeds 10-15 kt with gusts to 20 kt. Seas
will average 3-4 ft nearshore and 4-5 ft offshore.
Tuesday through Saturday: Winds will begin to increase Tuesday as
the pressure gradient tightens between high pressure building from
the north and tropical cyclone Matthew moving north toward the
Bahamas. Small Craft Advisories will therefore go into effect for
all coastal waters starting at 18z Tuesday and will likely persist
at least up to the time Matthew tracks near the Southeast coast late
week and weekend. Later in the week, deteriorating conditions will
depend greatly on the track and strength of Matthew, which is
forecast by the NHC/WPC to track north from the Bahamas while
remaining off the Southeast Georgia and Southeast South Carolina
coast. However, considerable uncertainty remains in the forecast at
this time for late week/weekend so mariners should regularly check
the latest forecast. As of now, sustained tropical storm force winds
could start over coastal waters as early as Wednesday night,
especially beyond 20 nm, then continue through at least Friday night
for all waters. Seas will also build significantly Thursday night
into Friday, possibly reaching 20 feet beyond 20 nm from the coast.
Rip Currents: Increasing swell and stronger onshore winds this
afternoon warrant a moderate risk for the GA coastline on Tuesday.
An enhanced risk is expected mid to late week due to increasing
winds/swells associated with tropical cyclone Matthew shifting along
the Southeast coast.
&&
.TIDES/COASTAL FLOODING...
Tide levels are expected to increase into at least Friday or until
tropical cyclone Matthew moves north of the area. At this time, the
storm is expected to remain offshore, so the risk of a significant
storm surge associated with a landfall is not likely. However,
uncertainty in the track and intensity of Matthew could result in
significant forecast changes. Regardless of the track, tides could
still get high enough to produce at least minor saltwater inundation
due to persistent strong northeast winds, especially along the SC
coast.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory from 2 PM Tuesday to 4 PM EDT Saturday
for AMZ350-352-354-374.
&&
$$
NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service State College PA
1136 PM EDT Mon Oct 3 2016
.SYNOPSIS...
A weakening upper low over New Jersey will push off the coast
later tonight. A ridge of high pressure will build east into
Pennsylvania behind this system, and will likely remain over the
area through the end of the work week, bringing mainly dry and
slightly milder conditions across Central Pennsylvania.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Mostly clear skies and a light wind will promote areas of fog
late tonight. Latest SREF, HRRR and downscaled NAM all suggest
the fog will be most prevalent over the Northern Mtns, but also
expect some valley fog toward dawn in the central/southern
valleys.
Lows will drop back into the upper 40s across the Allegheny
Plateau, to the low 50s over the Susq Valley.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Tuesday should start off partly to mostly sunny (other than for
patches of early morning fog and stratus), but as sfc high drifts
off the New England coast, a strengthening easterly flow off the
Atlantic will likely cause low clouds to work into the area from
the east. Model RH fields suggest the eastern counties stand the
best chance for becoming clouded over.
Have edged temps down a bit based on developing easterly flow and
cloud cover, with max temps likely ranging from the mid to upper
60s across most of Central Pa.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Upper ridging is forecast to build over the eastern United State
through the weekend. This will support high pressure at the
surface, providing the state with a stretch of fair and warmer
weather for much of the work week. The surface high is forecast
to move off the New England coast during the weekend.
Developing and eventually deepening east-serly flow around the
surface high will bring a return of llvl moisture and possibly
periods of stratus/strato cu clouds during the Wed-Friday period.
The target area for the most clouds (and even some drizzle or
even a brief shower) during the middle and end of the week will
be across southern PA and the Laurel Highlands.
How extensive the cloud cover will be (and if it will be
sufficient to generate drizzle or even rain) is still a tough
question. Part this will depend on the northward influence of
Hurricane Matthew.
The 00Z GFS brings a potent Matthew across the Western Bahamas
then has it paralleling the SE U.S. and Carolina coast late in the
week...before projecting it to get captured by a deepening upper
trough and accelerating north into Long Island next Sat/Sat night.
GEFS has roughly the same track, but as expected becomes more
diffuse through time with the location and intensity of the
storm`s center just off the East Coast.
The 30/12z operational ECMWF parked the storm over or just to the
north of the Bahamas for a prolonged period during the middle to
latter part of the upcoming week, which was a low confidence
solution.
A significant northern stream trof and associated cold front are
forecast to pushed east through the state late in the weekend.
This will be a push of noticelby cooler air for the start of next
week.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Just a few clouds left. Already some dense fog at times at sites
such as IPT, UNV, and BFD. Nothing at the office at 1130 PM.
03Z TAFS sent.
Earlier discussion below.
Showers gone as of 830 PM.
00Z TAFS sent.
Dewpoints are quite hight still, and expect clouds tonight to
fall apart, unlike last night, so expect some fog. Some fog
will be on the dense side, given recent wet spell. Nights fairly
long now as well.
Expect fog to burn off by 15Z. There could a period of MVFR
cigs across the east as the fog burns off, given the easterly
flow. Expect any low clouds to become more scattered later in the
day.
Outlook...
Wed-Fri...Possible restrictions with low clouds and easterly flow.
Becoming VFR each afternoon.
Sat...Chance of showers with cold front.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Fitzgerald/La Corte
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Lambert
LONG TERM...Lambert/Gartner
AVIATION...Martin
Area Forecast Discussion
National Weather Service Quad Cities IA IL
638 PM CDT MON OCT 3 2016
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 308 PM CDT Mon Oct 3 2016
18Z surface data has high pressure from the Great Lakes to the Gulf
Coast while a storm system was organizing in the Rockies. Dew points
were in the 50s from the Great Lakes and Plain with 60s in the lower
Mississippi Valley.
&&
.SHORT TERM...(This Evening through Tuesday)
ISSUED AT 308 PM CDT Mon Oct 3 2016
Dry conditions expected from late this afternoon through Tuesday.
The persistent inversion aloft is keeping the clouds in place across
the area. RAP trends indicate clouds should remain in place for much
of the area tonight. The exception appears to be the northwest third
of the area which may see the diurnal clouds break up after sunset.
Some patchy fog may or may not develop late tonight where skies
briefly clear.
Gradually increasing flow aloft should help break up the clouds
starting late Tuesday morning and continuing through the afternoon.
How long the clouds remain in place will half an impact on
temperatures. However, it does appear that Tuesday will be warmer.
.LONG TERM...(Tuesday Night through Monday)
ISSUED AT 330 PM CDT Mon Oct 3 2016
Main forecast concern for the long term are the chances for rain and
thunderstorms starting tomorrow night through part of the day
Friday. A series of trofs will affect the area leading to multiple
rounds of showers and thunderstorms. Some of these storms could be
strong to severe, especially on Wednesday and Thursday. The SPC has
the area in a marginal risk of severe weather Wednesday and a 15%
risk across the far south on Thursday.
At the beginning of the long term the guidance suggests convection
will be ongoing across western Iowa. These showers and storms will
slowly progress to the east through the overnight hours as the wave
moves east. A warm front will try to lift through the area. Deep
layer shear is close to 50 kts across the area. The bulk of this
shear exists in the lowest 0-3km layer, where values of 35 to 40 kts
are forecast. While storms should be coming in with the lowest
instability, these strong shear values suggest a HSLC environment.
This will need to be monitored for potential wind and tornado
threat. The NCAR 3-km ensemble suggests the potential for rotating
storms across western IA during the afternoon and evening.
Wednesday, have continued with drier forecast with ridging moving
into the area. Latest guidance suggest MCS development that will
run across the CWA overnight. This MCS will be contingent on where
the front is across the area. With this detail tied to mesoscale
phenomena, the forecastability of this MCS location remains low. If
this MCS occurs across our area, there may be residual OFBs that
could affect Thursday`s severe weather potential.
Thursday, the main wave moves across the CWA, bringing with it a low
and the renewed threat for severe weather. Current guidance pulls
the low and warm front north of the area. This may be difficult if
an MCS forms the night before. Regardless, shear and instability
parameters suggest possible strong to severe storms again. It is
imperative to note that these threats are completely contingent on
what occurs the day before as the mesoscale features will dictate
what happens.
After this, high pressure moves into the area and suggests a quiet
weekend. Models diverge in solutions for next week, so confidence
is low in the current forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
ISSUED AT 635 PM CDT Mon Oct 3 2016
The persistent stratocumulus deck may last another 24 hours, with
a few breaks for clear skies possible. This has a good potential
to save our area from having fog and low cloud development
overnight, so the gloomy conditions aren`t all bad. Expected cigs
to vary between 3500 and 4500 ft will be forecast in all sites,
expect for some 3000 MVFR stratus around DBQ overnight, as the
light southeast flow supports upslope cloud saturation as a
slightly lower level in that area of northeast Iowa.
ERVIN
&&
.DVN Watches/Warnings/Advisories...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...Gibbs
AVIATION...Ervin
Area Forecast Discussion
National Weather Service Grand Forks ND
949 PM CDT Mon Oct 3 2016
.UPDATE...
Issued at 948 PM CDT Mon Oct 3 2016
Based on coordination with WFO BIS did up pops a bit to likely
overnight as there will be some precipitation as band of showers
move northward from eastern SD. O/w no changes.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 311 PM CDT Mon Oct 3 2016
Precipitation timing and strength will be the primary headaches
for the period.
The upper low currently over WY will lift north and eastward
towawrds western ND tonight and tomorrow. The surface low will
come up along the MT/ND border tonight, keeping southeasterly
winds over our CWA that will remain fairly breezy. With the
increasing clouds and good mixing from the winds, lows tonight
will be very warm for the season, staying in the 50s to low 60s.
A few of the short range models have a preliminary round of
showers and storms moving into the western CWA this evening,
although the HRRR and RAP have been backing off on this idea and
are drier. The global models are evenly split between those
bringing in precip this evening and the later solutions. Given the
current track of convection over western ND is nearly due north,
think the best chances will be later tonight as the low pressure
system gets a bit closer and 850mb warm air advection picks up.
Have some low POPs in the far western tier this evening for any
stray showers out ahead of the main system, but think the main
show will be after midnight. There is some weak elevated CAPE so
kept thunder mention going.
Tomorrow, the surface trough axis and a cold front will move into
the CWA as the low center wraps up to our northwest. The models
show signs of the first round of activity in the morning fizzling
out and redevelopment across the MN counties by afternoon as the
frontal boundary approaches. Going forecast had highest POPs in
our east Tuesday afternoon and this seems to fit the latest runs.
Depending how much destabilization we get ahead of the afternoon
development, some storms could become strong to severe and a
marginal risk now includes our southeastern counties. NAM
currently has CAPE values around 500 J/kg or less, but with deep
bulk shear up around 40 to 50 kts by Tuesday evening stronger
cells are possible.
.LONG TERM...(Tuesday night through Monday)
Issued at 311 PM CDT Mon Oct 3 2016
Wednesday through Thursday...Still looks like a dry slot situation
will develop later Tue night as stacked low hangs way back over
NW North Dakota. Some def zone pcpn is possible during part of
Wednesday as the low structure moves toward Winnipeg. Best area
for this round of pcpn will be along a tract well north of US 2 .
Attention will then shift to the much cooler air mass diving in
behind this system evidenced in part by subzero 850 mb temps
showing up the far west forecast area early Thursday morning. Not
showing any pops for the day on Thursday, although patchy to areas
of frost should start showing up during the morning over the
Devils Lake basin.
Friday through Monday...Minimal if any pcpn is likely for the Friday
through Monday time interval. More widespread frost certainly
likely Friday and Saturday morning with freeze risks increasing as
surface temps drop to near 32 over a substantial portion of the
region. Chilly highs mostly in the 40s on Friday will moderate
only a couple of degrees on Saturday. Manitoba high pressure
should drift to Minnesota late Sunday setting up weak return flow
and milder temps by late afternoon. Stronger warm air advection
Monday lofting 850 mb levels into double digits above zero would
be reflected at surface with highs in the 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 656 PM CDT Mon Oct 3 2016
VFR for the tonight...though showers and a few t-storms will
impact DVL TAF site area later this evening-overnight. Activity
will reach GFK-FAR late tonight-Tuesday morning and spread east
into BJI area Tues midday-aftn. Overall VFR initially but
trending toward some MVFR cigs as the rain saturates the lower
levels more. Gusty south-southeast winds into Tuesday. Note DVL
AWOS data is not representative. FAA maintenance has been
notified.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Riddle
SHORT TERM...JR
LONG TERM...WJB
AVIATION...Riddle
Area Forecast Discussion
National Weather Service Hastings NE
953 PM CDT MON OCT 3 2016
.UPDATE...
Issued at 951 PM CDT Mon Oct 3 2016
Updated the forecast overnight to significantly reduce chance of
precipitation, especially west/central. Convection that was coming
toward us has died off significantly and the HRRR seems to be
handling this quite well. If the HRRR continues to be correct,
most of the CWA should be dry for much of the night, except
perhaps our far north and our east toward dawn with redevelopment.
I have trended POPs toward this scenario.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 330 PM CDT Mon Oct 3 2016
Very windy conditions across the forecast area this afternoon will
be slow to subside this evening...as a strong pressure gradient
remains in place across the region thanks to a deepening low
pressure system on the lee side of the Rockies. Expect this
surface low to eventually shift into the plains overnight as the
upper level low lifts into the northern Rockies and the longwave
trough becomes more negatively tilted...forcing the low level
trough and associated frontal boundary across the region.
While the overall synoptic progression is fairly well understood
over the next 12 to 24 hours...the details of potential
thunderstorms...their coverage and chance for embedded severe
cells...still has quite a bit of uncertainty. Due to the timing of
this front...only weak elevated instability...and modest forcing
from the front itself...there is definitely the potential that
most areas will remain dry overnight...with the best chance for
any convective/severe activity only across the western most
portion of the forecast area as the high plains convection may
hold onto its intensity just long enough to affect areas primarily
west of highway 183. Further east...models are in less agreement
keeping convection going...although the modest LLJ indicated by
the NAM may be enough to bring a swath of non-severe thunderstorms
across the entire forecast area after around midnight...with
further intensification of this line as the front moves into
eastern Nebraska during the morning hours Tuesday. With better
instability and better timing of the front affecting eastern
Nebraska tomorrow...any severe thunderstorms should only brush the
easternmost fringes of the local area at best.
Overall...did not drastically change the inherited short term
forecast as there is still quite a bit of uncertainty...but did
trim the western edge of convection during the daytime hours
tomorrow...as model consensus has the front track eastward a bit
quicker than previously forecast. Otherwise...temperature/wind
wise...expect much calmer winds tomorrow across the local area
with a drop in afternoon temps of 5-10 degrees from todays
readings.
.LONG TERM...(Tuesday night through Monday)
Issued at 330 PM CDT Mon Oct 3 2016
Southwesterly flow aloft and a cooler airmass will be in place to
start the extended periods...with temperatures returning to near
normal values on Tuesday and Wednesday. Expect the next embedded
upper level system and surface cold front to bring another chance
for showers and thunderstorms to the local area Wednesday night
into Thursday...with much cooler air in its wake. This should take
afternoon temperatures down to near or below 60 degrees for the
latter half of the work week...with the potential for some frost
early both Friday and Saturday mornings. While not a sure
thing...with light winds...mainly cloud free skies and dew points
currently forecast near freezing...opted to add the wording for
frost primarily northwest of the tri-cities early Friday
morning...with much more widespread frost potential expected
Saturday morning.
Otherwise...expect the low level flow to shift and become more
southerly late in the weekend...ushering in a warmer and more
seasonable airmass...with the next upper level disturbance in
southwesterly flow bringing another chance for some precipitation
early next week.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday evening)
Issued at 642 PM CDT Mon Oct 3 2016
Main concern will be low-level wind shear, especially when surface
wind slacks off a bit this evening. With a developing low-level
jet, this appears to be a near certainty for KGRI, but KEAR may be
just far enough west to not technically make low-level wind shear
criteria. Nevertheless, KEAR was included, since this would be a
very close call. Keeping ceilings VFR, despite some numerical
models indicating the KGRI could briefly dip to MVFR Tuesday as a
cold front swings through.
&&
.GID Watches/Warnings/Advisories...
NE...None.
KS...None.
&&
$$
UPDATE...Heinlein
SHORT TERM...Rossi
LONG TERM...Rossi
AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Lincoln IL
903 PM CDT MON OCT 3 2016
.UPDATE...
Issued at 855 PM CDT Mon Oct 3 2016
Surface high pressure continues to edge slowly away from the
Midwest this evening with the extensive cloud cover that was over
our area through much of the day starting to slowly erode.
Forecast soundings continue to show clouds around 3500-4500 feet
overnight at a few locations with the HRRR continuing to depict a
cloud band especially across west central Illinois overnight
before shifting to our north by morning. None of the soundings or
short term forecast solutions were very aggressive with fog
overnight but with our gradient still expected to be weak and
several periods where there will be clear skies overnight, patchy
fog still appears possible. Only made some minor tweaks to the
early evening temperature trends, otherwise, the rest of the
forecast has a good handle on the evening and overnight trends. As
a result, no ZFP update will be needed at this time.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 247 PM CDT Mon Oct 3 2016
Weak upper level ridging continues to dominate much of the Midwest
with an upper low spinning over the Rockies. The sfc system
associated with that low is still developing well to the west. For
the mid Mississippi River Valley and the Great Lakes, sfc ridge is
bringing quiet weather overall. However, some llvl moisture is
trapped and has given some patchy dense fog across the area in the
overnights, and enough to develop a cu field during the day. These
are the same concerns that will run through at least the next couple
days.
A substantial cu field today has limited daytime heating and
moisture mixing out. As a result, so far the dewpoints have not
dropped much at all. Although clearing is anticipated for the
evening...how much of the llvl moisture/cloud cover will actually
dissipate is questionable. Southeasterly winds should remain up a
bit overnight, ushering in warmer air and moisture. However, the
winds and the cloud cover should limit most of the vis drop. The
area that may see the exception is along and south of I-70 where the
winds are lighter closer to the ridge axis. Tomorrow is a similar
day, with max temps a few degrees warmer, and the cu field
developing before mid day.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 247 PM CDT Mon Oct 3 2016
A longwave trough developing over the western half of the U.S. will
begin to affect the area starting late Tuesday night as an initial
embedded shortwave ejects from the southern Plains into the upper
Midwest. This feature looks to primarily affect northwestern
Illinois and have the highest chance of precipitation (30-40
percent) from near I-55 northwestward. Behind this feature...a moist
warm advection pattern will set up later Wednesday into Thursday
bringing continued chances for showers and thunderstorms as a cold
front begins to take shape and approach from the NW. The cold front
looks to cross central IL during the day Friday with a better chance
for thunderstorms ahead of the feature and showers tapering off
behind. Chances for thunderstorms generally remain northwest of I-70
until just before the frontal passage...with some slight chances to
the southeast. Dry weather and cooler temperatures look on track
behind the front for the weekend and into early next week as high
pressure moves over the area.
SPC day-3 outlook has a marginal risk of severe thunderstorms for
late Wed afternoon into Wed evening over the IL river valley where
stronger wind shear and CAPE is forecast with warm air advection
pattern and dewpoints rising into the low to mid 60s. For Thursday
afternoon and evening...another shortwave looks on track to eject
through the mid-Mississippi valley and could bring another focus for
stronger storms over west central IL.
Temperatures will be quite warm prior to the cold frontal passage
with highs generally low to mid 80s Wednesday and Thursday, and lows
in the lower to mid 60s. Highs Friday will range from around 64 in
Galesburg to near 80 in Lawrenceville. Lows in the 40s and highs in
the 60s will then take over for the weekend...likely warming
slightly by Monday.
Powerful Category 4 Hurricane Matthew with sustained winds of 140
mph was located near latitude 15.9 North and longitude 74.8 West,
drifting slowly north at 6 mph at 2 pm EDT. Hurricane Matthew is
forecast by the National Hurricane Center (NHC) to move northward
through the Caribbean to near the southeast US Coast through the
upcoming week. Stay tuned to forecasts from the National Hurricane
Center (www.nhc.noaa.gov) if you have travel plans to the the
Caribbean or the east coast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 647 PM CDT Mon Oct 3 2016
Stratocu with bases around 6k ft should erode over the next
several hours, similar to last night. The potential exists for
some broken ceilings to linger through 06z at some sites however
the overall trend should be decreasing overnight. The next
question is potential for fog development late tonight. Guidance
suggests some light fog may be possible towards sunrise but with
ridge axis shifting farther east overnight, feel enough wind will
keep mixing up and limit fog. Southeast winds will increase
around 10-12 kts after 15z as pressure gradient tightens ahead of
low pressure over the Plains.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...HJS
LONG TERM...Onton
AVIATION...25
Area Forecast Discussion
National Weather Service Sioux Falls SD
328 AM CDT Tue Oct 4 2016
.SHORT TERM...(Today and Tonight)
Issued at 322 AM CDT Tue Oct 4 2016
Current shower and storm bands drifting east toward Interstate 29
are being handled fairly well by the short term models, including
both HRRR models and the RAP. These bands should continue moving
east at a slowing pace with activity expected to decrease in
coverage for a few hours. Showers and storms will then start to
increase again later this morning through this afternoon as strong
upper support approaches, and the approach of the somewhat diffuse
surface cold front will contribute to an increase in activity. This
redevelopment during the day will likely happen over and even west of
the current activity, although do not see much redeveloping over the
far western part of the area, meaning Gregory to Chamberlain to
west of Huron.
Late today and this evening, after redeveloping, the showers and
storms will again do an overall east push, slowly at first, then
accelerating tonight, with an increasingly fast clearing out of
showers and storms by late tonight. It appears that the most
organized and concentrated activity will spend the greatest amount
of time over the area east of Interstate 29 late this afternoon and
this evening, so the greatest heavy rainfall potential will be in
southwest MN and northwest IA. Modest CAPE and the lack of summer
type moisture availability should limit rainfall intensity, and
adding some recent dry weather, a flash flood watch is not being
considered. However, over the span of 6 to 12 hours, figure there
could be local areas of 2 to 3 inches of rain.
Severe storms today seem unlikely with MLCAPE probably staying in
the triple digits. Decent low level wind fields and directional
shear could give rise to a surprise or two in the form of
marginally damaging gusts, most likely I29 and east late in the day
into the early evening when the well defined strong short wave
maximizes those wind parameters.
High temperatures today should be in the mid 60s to low 70s, with
the warmer readings far west and east, on either side of the most
concentrated late morning and early afternoon precipitation. Winds
will be tolerably below wind advisory levels, with the limited
heating and decreasing low level speeds. Lows tonight should be int
he mid 40s to lower 50s, with cooling and decreasing clouds allowing
temperatures to cool that much late tonight.
.LONG TERM...(Wednesday through Monday)
Issued at 322 AM CDT Tue Oct 4 2016
Medium and extended range forecasts needed only minor adjustments
tonight, as model guidance is rather consistent in advertising two
primary risks. Increased rain chances Thursday afternoon and
night, and potential frost/freeze conditions Friday, Saturday, and
Sunday mornings.
Expected a dry Wednesday as a surface cold front begins to settle
southward into the area. There is a layer of mid-lvl moisture that
is hanging around the region, generally at or above 700 mb. Can a
sprinkle be ruled out? Probably not, but the chances are too low to
include at this time.
Medium range guidance has slowed down the arrival of deeper moisture
and larger scale lift expected to move across the region on
Thursday. Strong synoptic lift provided by mid-lvl shortwave energy
and a favorable upr jet structure, overtop increasing 700:600 mb
frontogenesis should produce increasing risk of light rain falls
through Thursday morning. The highest risks arrive Thursday
afternoon and evening as deformation rain band slides through the
CWA. Have bumped PoPs to likely levels (and these will likely
continue to climb), with the biggest uncertainty on the northwestern
edge of the rain band. Dry air intruding from the northwest will
make this a very sharp precipitation gradient. PoPs from Huron to
Chamberlain may be in a higher level of flux than normal.
The Friday-Sunday period will feature dry conditions, despite model
differences in the synoptic level features. The primary differences
fall with the progression of an upr trough through the region on
Friday. A sharper trough axis on the GFS pulls stronger high
pressure southeast, and results in less cloud cover and colder
nights. The ECMWF is slowly with the trough, more positively tilted
and results in a lingering of stratus through Saturday. The end
result is a large differential in daybreak sfc temperatures. This
will obviously impact any risk of frost or freeze at the end of the
week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1032 PM CDT Mon Oct 3 2016
Southeasterly winds will continue to gust 20 to 25 kts through
early Tuesday afternoon. Otherwise, showers and isolated
thunderstorms will develop from west to east across the area
tonight, decreasing some by Tuesday morning, then become more
widespread from the I-29 corridor and eastward by mid to late
morning on Tuesday. Ceilings will lower into the MVFR and IFR
range by Tuesday morning with the intensification of the
precipitation. Conditions will begin to improve by Tuesday
evening.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
SHORT TERM...
LONG TERM...Dux
AVIATION...JM
Area Forecast Discussion
National Weather Service Marquette MI
435 AM EDT Tue Oct 4 2016
.SHORT TERM...(Today and tonight)
Issued at 433 AM EDT TUE OCT 4 2016
Water vapor imagery and RAP analysis show a trof over the Rockies
with a vigorous shortwave over se MT and a downstream ridge over the
Great Lakes. Ahead of the trof and its associated cold front,
shra/tsra are lined up from the eastern Dakotas/western MN to the
southern plains. Closer to home, with the Upper Lakes now in the the
southerly flow btwn the Plains cold front and high pres centered in
the vcnty of northern ME, low level moisture that was over Lower MI,
IN, IL 24hrs ago has advected into the fcst area. Added
warmth/moisture from Lake MI and upsloping is further aiding the
cloud expansion early this morning. So far, not much in the way of
fog has been indicated at obs sites, but cigs are falling in central
Upper Michigan where upsloping is strongest.
With dwpts in the upper 50s at KMNM/KESC/KISQ and sse flow advecting
these higher dwpts upslope into areas where current temps are in the
low/mid 50s, cigs should continue to lower this morning, and may yet
see fog and perhaps some patchy -dz develop. This is most likely to
occur in central Upper MI where upsloping is more pronounced.
Otherwise, it appears quite a bit of cloud cover will mostly prevail
today given upstream cloud cover per satellite imagery. Areas that
see downsloping under southerly winds will have the best shot at
seeing more sun than clouds today. Despite less sunshine today, max
temps will be similar to yesterday due to the mild start to the day,
mostly mid 60s to 70F.
Tonight, the vigorous shortwave now over se MT will drift ne to the
ND/Saskatchewan border while a shortwave trof pivots ne thru the
Plains toward the Upper Mississippi valley. This shortwave trof will
help to propel cold front to ne MN/western WI by 12z Wed. With
excellent multi-model agreement on timing pcpn associated with
shortwave/cold front, including the 10 member NCAR ensembles, there
is little reason to deviate from that guidance. Fcst will show schc
to low chc pops reaching only western Gogebic County/far western
Ontonagon county 10-11z. Tight pres gradient/southerly winds and
precipitable water of 0.8 to 1 inch will lead to an unseasonably
warm night for early Oct. Min temps in the mid 50s to around 60F
will be around 20 degrees above normal and will be more typical of
normal max temps at this time of year.
.LONG TERM...(Wednesday through Monday)
Issued at 357 AM EDT TUE OCT 4 2016
A vigorous shrtwv/sfc lo pres lifting ne fm the Plains into scentral
Canada wl drag a weak cold fnt acrs the Upr Lks on Wed, accompanied
by a band of showers. Although there wl be a drying trend on Wed ngt
into Thu behind the fropa, another disturbance/lo pres lifting newd
within the larger scale sw flow alf btwn a rdg over the se CONUS and
troffing over the w wl bring another round of showers Thu ngt into
Fri. Temps wl remain above normal until Fri when much cooler air wl
arrive behind the cold fnt attendant to the exiting lo pres in
Ontario. The arrival of this cooler air behind the lo pres could
cause some lk effect showers Fri ngt into Sat ngt before hi pres
blds into the area later in the weekend and causes a drying trend.
Warmer air wl return early week once this trailing hi pres shifts to
the e and there is a wshft to the sw.
Wed...Deep shrtwv/lo pres over far sw Manitoba on Wed mrng are fcst
to move slowly to the ne thru the day. The attendant weak cold
fnt/warm conveyor belt mstr ribbon/axis of deep lyr qvector cnvgc wl
cross the Upr Lks on Wed accompanied by a band of showers/perhaps a
TS. Even though pwat near 1.50 inches wl be 200-250 pct of normal,
passage of the stronger shrtwv/forcing well to the nw and quick
moving fnt/warm conveyor belt wl limit pcpn totals. Vigorous deep
lyr drying/qvector dvgc in the wake of the fropa wl end the pcpn and
even allow a return of some sunshine by late in the day over the w.
Since the airmass following the fropa wl be Pacific in origon under
a sw flow aloft btwn the lingering wrn trof and the persistent upr
rdg over the se CONUS, max temps into the 60s up to 70 wl remain
above normal.
Wed ngt...Weak rdg of hi pres/mid lvl dry air following the fropa wl
bring a period of dry wx. But with h85 temps falling no lower than
8C over the w, temps wl remain above normal despite expected clr-
pcldy skies. A steady wsw wind wl further limit the diurnal temp
drop, especially over the w where a sharper pres gradient is fcst to
prevail.
Thu...Most of the models indicate Thu wl be a dry day despite some
incrsg clds in the sw flow alf to the ne of a shrtwv/dvlpg lo pres
in the central Plains. Some recent models, including the 18Z GFS and
12Z ECMWF, have hinted a weak shrtwv riding newd along the stalled
fnt just to the se of Upr MI could cause some showers over the se
cwa, so wl retain some lo chc pops in that area as this scenario is
not unreasonable considering the persistent hi amplitude upr rdg
over the se CONUS and sw flow alf. Even if there are more clds over
the se that would limit the diurnal temp rise there, fcst h85 temps
btwn 10C over the w and 12C over the e indicate another unseasonably
warm day is in store. If and where there is more sunshine, temps
could rise aoa 70.
Thu ngt/Fri...Models are in fairly good agreement showing the Plains
shrtwv/lo pres riding newd within the sw flow alf thru the Upr Lks
on Thu ngt and into Ontario on Fri. A period of vigorous dpva/deep
lyr qvector cnvgc/upr dvgc with pwat aoa 1.50 inch wl support hi
likely/categorical pops and some mdt rain/perhaps a TS over mainly
the se cwa before mid lvl subsidence/ drying in the wake of the
shrtwv/lo pres lifting to the ne and passing attendant cold fnt
diminish the pops w-e on Fri. Recent GFS runs have been slower to
push the cold fnt too far to the e and thus end the pcpn over the se
cwa under a more ssw flow alf, not unreasonable considering the hi
amplitude upr rdg over the se CONUS that would tend to slow the ewd
progression of the deep drying. Fri wl be a much cooler day as h85
temps are fcst to fall to arnd -1C over the w toward 00Z Sat behind
the fropa.
Extended...After some initial drying under a more acyc nw flow into
Fri ngt in the wake of the exiting lo to the ne, the arrival of
colder air/h85 temps as lo as -3 to -4C on Fri ngt/Sat and aprch of
another shrtwv/some deeper mstr fm the w on Sat, a period of lk
effect showers wl be psbl and focused on a lk induced trof that some
of the models dvlp over the relatively warm waters of Lk Sup on Sat.
While the fcst h85 temps sug some snow could mix with the pcpn over
mainly the hier terrain of the nw cwa, fcst unstable llvl lapse
rates/warmer sfc temps indicate this ptype is too unlikely to
include in the fcst attm. The arrival of hgt rises/more acyc flow in
the wake of the passing shrtwv on Sat ngt/Sun wl diminish the lk
effect pcpn. However, some of the longer range models maintain lower
hgts and show another shrtwv aprchg on Sun that would bring more
clds and some sct showers. But even these models show rising hgts/
more acyc flow arriving on Mon that would support a drying trend
early next week. As the hi shifts to the e on Tue, a return sw flow
wl bring a return of warmer air. Since some of the guidance has
shown a cold fnt wl aprch on Tue, the fcst wl include a lo chc of
some showers on Tue.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 129 AM EDT TUE OCT 4 2016
Expect MVFR cigs to gradually lower at KSAW overnight with upslope
sse flow. However, confidence is lower with potential of IFR/LIFR
cigs late in the night into the morning hrs. With daytime heating,
cigs should improve to MVFR by late morning. The low level flow will
be less favorable for stratus at KIWD and KCMX where VFR conditions
should prevail.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 433 AM EDT TUE OCT 4 2016
SE to S winds will generally be on a gradual increase thru Wed
morning as a cold front approaches from the west. Winds will become
strongest over central and eastern Lake Superior, reaching the 20-
30kt range late tonight/Wed. The cold front will sweep across Lake
Superior Wed aftn/evening. While SW winds as high as 15-25kt should
occur behind the front Wed night into Thu morning, strongest between
Isle Royale and the Keweenaw Peninsula, the pressure gradient and
winds will weaken for a time Thu aftn and night as a low pressure
trough develops over the Upper Lakes ahead of a low pressure wave
developing over the southern Plains. After this low pressure wave
passes late Thu night/early Fri morning, NW winds up to 20-25kt will
develop on Fri, strongest over the e half of Lake Superior. NW winds
up to 20kt will linger on Sat.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...KC
AVIATION...JLB
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Morristown TN
345 AM EDT TUE OCT 4 2016
.SHORT TERM (Today and Tonight)...
Current water vapor imagery and RAP upper air analysis indicate a
closed low across the Mid-Atlantic and a ridge across the Great
Lakes. A decent upper level jet of 80-100 kts exist just off the
Atlantic coast. This puts the Carolinas in the entrance region of
the jet and so far have seen more cloud cover to the east of the
mountains. Closer to home, there are a few clouds thanks to some
weak cyclonic flow in the mid-levels. At the surface, there appears
to be an inverted trough across the forecast area with easterly
winds in SW VA and northeasterly winds across the Central valley.
PW values range from 0.8-1.0 inches. These values are around to
slightly below normal for early October. Therefore, have only seen
an uptick in cloud cover with this surface inverted trough. Surface
highs pressure is currently in place across New England and this
high is forecast to shift further to the east today. With this, low
level winds will take on a more southeasterly direction today.
These winds will provide a downsloping component across the region.
Due to this, increased highs by a degree or two across most of the
valley locations. Expect high temperatures will top out in the
upper 70s to mid 80s across most valley locations. Dry conditions
will persist into the overnight hours with lows in the mid 50s to
low 60s.
.LONG TERM (Wednesday through Monday)...
Warm and dry conditions continue Wednesday and Thursday with ridge
over the eastern seaboard into the southern Appalachians. Highs will
continue to be several degrees above normal with lows in the upper
40s to mid 50s Thursday and 50s Friday and highs in the upper 70s to
mid 80s. On Friday moisture from Hurricane Matthew will approach the
Carolinas and spread as far west as the Appalachians. A few showers
are possible through Friday night along the western edge of Matthew.
On Saturday a cold front and associated shortwave trough will move
across the forecast area. With limited moisture only a few showers
across northern sections. Warm temperatures several degrees above
normal will continue Friday and Saturday but cool to the mid 60s to
mid 70s Sunday and Monday behind the front.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 85 61 86 57 / 0 0 0 0
Knoxville McGhee Tyson Airport, TN 84 58 83 54 / 0 0 0 0
Oak Ridge, TN 84 58 84 55 / 0 0 0 0
Tri Cities Airport, TN 79 54 81 48 / 0 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&
$$
MA/TD
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
346 AM CDT TUE OCT 4 2016
.SHORT TERM...(Today and tonight)
Issued at 324 AM CDT Tue Oct 4 2016
Elevated showers and thunderstorms have developed across central
Kansas and into north central Kansas this morning since 06Z. The
storms have developed within the 50 to 55kt low level jet and
corresponding moisture axis and instability axis. Water vapor loop
this morning shows main upper low moving northeast across Montana
with trailing energy moving through the upper trough across southern
Colorado and associated mid level jet. Area of upper level
diffluence was noted across central Kansas into south central
Nebraska at 07Z. Short term high resolution models keep elevated
showers and thunderstorms going through mid to late morning across
northeast Kansas. Models also show persistent isentropic lift
through the day which could prolong the convection and clouds into
the afternoon hours which would temper the instability in northeast
Kansas. Dew point temps should increase into the lower 60s this
afternoon. Clearing is expected mid afternoon across central and
south central Kansas which will lead to increasing instability.
Forcing for ascent will increase with the approach of the mid level
moving out across the Central Plains. Forcing will be aided by the
left exit region of the upper level jet across north central and
northeast Kansas late this afternoon and evening. Shear and
instability will be sufficient for strong to severe storms with
large hail and winds the main hazards. A tornado or two is also
possible into the early evening hours. Storms should initially fire
near the surface front and dryline across central Kansas in the late
afternoon hours then move northeast. Models suggest a line will form
in the evening hours then move southeast across the area, exiting
southeast of I-35 during the overnight hours. Given precipitable
water values of 1.50 or higher locally heavy rainfall will also be
possible.
.LONG TERM...(Wednesday through Monday)
Issued at 324 AM CDT Tue Oct 4 2016
By Wednesday morning, a broad mid-level trough will be stretched
across the western and central U.S., with a surface cold front
tracking eastward across the CWA. Precipitation ahead of the front
should be out of the CWA by Wednesday morning, and with a strong cap
in place have stayed with a dry forecast for the daytime hours. This
cold front should lift northward as a warm front over the area again
by Wednesday night, with some scattered thunderstorms possible
overnight. Despite some modest instability of 1500-2000 J/kg of
CAPE and strong 0-6km bulk shear values of 40-50kts, model soundings
show a cap remaining in place during the evening, albeit weakening
though. So the question becomes whether or not the cap can weaken
enough for thunderstorms to develop and tap into the decent
instability and shear conditions in place. Due to the conditional
situation, a marginal risk for strong to severe storms remains in
place for Wednesday night.
The primary trough axis will finally shift into the Rockies on
Thursday and advance into the central U.S. Thursday night into
Friday. This advancing trough will help to push the boundary that
lifted northward as a warm front back eastward once again over the
CWA as a cold front. Some strong to severe storms may be possible
with this frontal passage as the cap weakens with 1000-2000 J/kg of
CAPE and 30-40kts of 0-6km bulk shear in place. The primary
concerns with any stronger storms will be large hail and strong
winds.
Cooler and drier conditions are expected by Friday as surface high
pressure surges into the central U.S. behind the exiting cold front.
High temperatures Friday and Saturday will only be in the 60s with
low temperatures plunging into the 40s and even into the upper 30s
Friday night. Surface high pressure will shift east of the area by
Sunday, with southerly winds boosting high temperatures back into
the lower 70s. Mid-level flow will become more zonal late weekend
into early next week, however models are showing the potential for
an embedded wave to develop within this flow Sunday night into
Monday. Models are different though in the strength of this wave
and, thus, the potential for scattered precipitation to develop. At
this time, have slight chance PoPs in place, but confidence is low.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday)
Issued at 1139 PM CDT Mon Oct 3 2016
Not much change in forecast thinking from the prev discussion.
Think that eventually isentropic assent and mid level lapse rates
around 7 C/km will lead to elevated showers and storms. Main
question is whether they linger though much of the day Tuesday.
RAP and NAM progs keep the upglide going through the afternoon
within the warm air advection pattern. So there is less confidence
in a break from precip late morning and early afternoon and will
keep a VCTS through the afternoon, trying to time the best
opportunity for storms with a TEMPO based off of high resolution
solutions.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...Wolters
Area Forecast Discussion
National Weather Service Denver/Boulder CO
920 AM MDT Tue Oct 4 2016
.UPDATE...
Issued at 912 AM MDT Tue Oct 4 2016
Conditions in the high country finally showing signs of
improvement this morning but have extended slgt chc of snow
through the rest of the morning. also lowered the max
temperatures slightly this aftn for the high country as well.
Some minor adjustments regarding the wind across the plains
otherwise rest of the grids okay.
&&
.SHORT TERM...(Tonight through Tuesday evening)
Issued at 400 AM MDT Tue Oct 4 2016
The decent westerly low level winds have only made as far east
into the plains to central Arapahoe and central Adams counties.
Weak north and northeasterly winds cover the rest of the plains.
The radars indicate some snow showers along the divide right now.
Models do bring an upper trough axis across the CWA today. The
flow aloft by mid afternoon is west-northwesterly. This increases
this evening and tonight with a westerly jet maximum over the
state. West winds aloft at about 100 knots are progged over the
CWA at 12Z Wednesday morning. There is fairly strong downward QG
motion today into this evening. Overnight, near neutral QG
vertical velocity is progged. The boundary layer flow will be
mostly downsloping today into early evening for most areas. Normal
drainage patterns kick in by mid evening. Speeds are fairly light
both periods. For moisture, there is not much, just a tad in the
mountains today and tonight, with a bit here and there over the
plains in the mid and upper levels. Precipitable water values are
in the 0.15 to 0.40 inch range today and tonight. There is no CAPE
progged over the CWA today or tonight. The QPF fields show a tiny
bit of measurable precipitation over the far northwestern corner
of the CWA today and nothing anywhere tonight. For pops, will go
with 10-20%s mainly just in the mountain zone today. For
temperatures, today`s highs are 2-7 C colder than yesterday`s.
.LONG TERM...(Wednesday through Monday)
Issued at 300 AM MDT Tue Oct 4 2016
Southwest flow aloft will be increasing Wednesday as another upper
trough digs south from the Pacific Northwest down into the
Northern and Central Rockies. A surface low will deepen over
southern Colorado in response, bringing northeasterly winds into
the forecast area. This will keep temperatures moderated and
similar to todays readings. Some mid-level moisture will push in
to bring scattered showers over the northern mountains in the
afternoon. Then low level moisture wrapping around combined with
QG ascent and an area of frontogenesis pushing into the state from
the north on Wednesday night will bring a chance for scattered
showers over the northern foothills and plains, with snow levels
around 7000 feet. A stronger cold front will push south into the
area overnight.
The upper trough axis will pass over the forecast area on
Thursday. Models are trending quicker with the trough passage,
although the EC seems to weak. Consensus shows areas of
precipitation spreading south over the area, though 700 mb flow is
almost too west of northerly to be good upslope, even though
surface flow will be northeasterly upslope. Given the 700mb flow,
confidence isn`t all that great on widespread precipitation, but
moderate upward QG motion may be enough to counteract that drying.
In terms of snow levels, another strong push of cold air is
expected Thursday along the plains. Wet-bulb zero heights range
from 6800 ft to 8500 ft between models. Dropping this 1000 feet
may allow to see some snow mixing as far down as over the
foothills, far western suburbs and Palmer Divide, but confidence
that we`ll see it over the rest of the plains is low. However
both the GFS and NAM have snow accumulations over the plains
during thursday morning and afternoon, up to 5 inches of the
higher spots. Think this is way over done. Could see some
accumulating snow over the far western suburbs and the Palmer
Divide, but it will likely melt on contact or quickly elsewhere
due to recent warm temperatures and it being during the day. The
mountains will likely see appreciable accumulations from this
storm, maybe in the 2 to 6 inch range at the higher elevations.
The upper trough will quickly push east with subsidence spreading
across the area late Thursday night to clear conditions quickly.
Clearing skies will mean temperatures likely falling below
freezing across the plains. Have cooled the forecasted minimums by
a degree or two with the trend of a faster departing trough.
An upper ridge will build over the area for Friday through the
weekend for warm and dry conditions under mostly clear skies.
Friday and Saturday will likely still be cooler than average
before the readings reach and warm above normal for Sunday and
Monday. The EC wants to bring some moisture into the central
mountains for Monday and Tuesday, will have a slight chance for
this.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 912 AM MDT Tue Oct 4 2016
VFR conditions expected through the period. southwest winds at
KDEN this morning will transition to northwest by 17z. latest
HRRR shows the wind transitioning to northeast this aftn...so have
included this in the tafs as well. Back to normal drainage wind
this evening.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Cooper
SHORT TERM...RJK
LONG TERM...Kriederman
AVIATION...Cooper
Area Forecast Discussion
National Weather Service Charleston SC
1022 AM EDT Tue Oct 4 2016
.SYNOPSIS...
High pressure will build over the eastern United States through
mid week. Hurricane Matthew is expected to move north from the
Bahamas later this week, possibly bringing significant impacts to
southeast South Carolina and southeast Georgia.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Confidence is increasing that Matthew will bring direct impacts to
the area. Recent model trends continue their westward jog with
Matthew, which is obviously concerning. Updated grids/text
products will be updated to reflect the 11 am NHC advisory.
Otherwise, RAP soundings show dry air remaining in place today as
inland high pressure wedge holds. Only exception is at the coast
where deeper moisture is present. Maintain 20-30% pops for coastal
areas, highest along the Georgia coast. Might need to bump up to
40% for coastal McIntosh where trajectories of marine activity
moving inland is the most ideal. Warmest conditions will be found
well inland where near near full insolation is occurring.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
High pressure will remain north of the area while tropical cyclone
Matthew moves north from the Bahamas. Expect a general deterioration
in conditions through Thursday night as Matthew draws closer to the
area, then a more rapid deterioration on Friday as the Category 2 or
potentially major hurricane approaches. Some uncertainty regarding
the track/strength of the storm remains and this will determine how
quickly and how much winds increase but based on the latest NHC
forecast sustained tropical storm force winds /39-73 mph/ are likely
to begin Friday, mainly near the coast.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Significant impacts from Hurricane Matthew are becoming more likely
late this week across southeast SC/GA!
The latest NHC forecast for Matthew indicates a Category 2
hurricane, possibly a Category 3 storm, impacting the area Friday
night into Saturday. Of course, there is still some uncertainty in
the track/strength of Matthew and thus pinpointing exact impacts is
impossible at this time. However, folks across southeast SC/GA
should prepare for hurricane force sustained winds /74+ mph/,
coastal flooding, heavy rainfall-induced freshwater flooding and
isolated tornadoes, especially near the coast. There is also the
potential for the center of Matthew to cross the coast and this
would increase the coastal flooding due to a potentially significant
storm surge, mainly to the north and east of the landfall
location.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
VFR through today. Low chances for MVFR ceilings later tonight
mainly at KSAV due to showers/tstms.
Extended Aviation Outlook: Flight restrictions likely due to low
clouds/showers Wed/Thu with at least tropical storm force /34+ kt/
winds mainly Fri night into Sat due to Hurricane Matthew as it
tracks north near the Southeast U.S. coast.
&&
.MARINE...
Today: Winds/seas will continue to increase within a tightening
pressure gradient. Small craft advisory in effect for all zones
except Charleston Harbor. Looks borderline in the Harbor right
now, but an advisory may be needed later today.
Wednesday through Sunday: Conditions will be going downhill ahead of
the approach of Hurricane Matthew moving north from the Bahamas.
There remains some uncertainty regarding the track/strength of
Matthew but dangerous conditions are becoming increasingly likely.
Sustained tropical storms force winds will likely start early Friday
across the GA waters and then spread northward before ending from
south to north Saturday. Sustained hurricane force winds are most
likely Friday night. Seas could reach near 20 feet in the eastern
portions of the nearshore waters and near 30 feet in the offshore GA
waters. Conditions will then slowly improve later this weekend as
winds turn offshore.
Rip Currents: Increasing swell and stronger onshore winds this
afternoon warrant a moderate risk for the GA coastline today.
Life-threatening rip currents are expected mid to late week due
to strong winds and large swells associated with Hurricane
Matthew.
&&
.TIDES/COASTAL FLOODING...
Tide levels are expected to increase until Hurricane Matthew
passes the area late this week. Anomalies are already running as
high as about 1 foot and these will continue to increase as
northeast winds strengthen across the area even well ahead of the
storm. Then, as Matthew approaches late this week there is a risk
that tide levels will be much higher, enough to produce significant
coastal flooding. This will especially be the case on the northern
side of where Matthew potentially makes landfall due to the storm
surge, or inland push of ocean water.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 10 AM EDT Sunday for AMZ350-352-354-
374.
&&
$$
ST
Area Forecast Discussion
National Weather Service Sioux Falls SD
647 AM CDT Tue Oct 4 2016
.SHORT TERM...(Today and Tonight)
Issued at 322 AM CDT Tue Oct 4 2016
Current shower and storm bands drifting east toward Interstate 29
are being handled fairly well by the short term models, including
both HRRR models and the RAP. These bands should continue moving
east at a slowing pace with activity expected to decrease in
coverage for a few hours. Showers and storms will then start to
increase again later this morning through this afternoon as strong
upper support approaches, and the approach of the somewhat diffuse
surface cold front will contribute to an increase in activity. This
redevelopment during the day will likely happen over and even west of
the current activity, although do not see much redeveloping over the
far western part of the area, meaning Gregory to Chamberlain to
west of Huron.
Late today and this evening, after redeveloping, the showers and
storms will again do an overall east push, slowly at first, then
accelerating tonight, with an increasingly fast clearing out of
showers and storms by late tonight. It appears that the most
organized and concentrated activity will spend the greatest amount
of time over the area east of Interstate 29 late this afternoon and
this evening, so the greatest heavy rainfall potential will be in
southwest MN and northwest IA. Modest CAPE and the lack of summer
type moisture availability should limit rainfall intensity, and
adding some recent dry weather, a flash flood watch is not being
considered. However, over the span of 6 to 12 hours, figure there
could be local areas of 2 to 3 inches of rain.
Severe storms today seem unlikely with MLCAPE probably staying in
the triple digits. Decent low level wind fields and directional
shear could give rise to a surprise or two in the form of
marginally damaging gusts, most likely I29 and east late in the day
into the early evening when the well defined strong short wave
maximizes those wind parameters.
High temperatures today should be in the mid 60s to low 70s, with
the warmer readings far west and east, on either side of the most
concentrated late morning and early afternoon precipitation. Winds
will be tolerably below wind advisory levels, with the limited
heating and decreasing low level speeds. Lows tonight should be int
he mid 40s to lower 50s, with cooling and decreasing clouds allowing
temperatures to cool that much late tonight.
.LONG TERM...(Wednesday through Monday)
Issued at 322 AM CDT Tue Oct 4 2016
Medium and extended range forecasts needed only minor adjustments
tonight, as model guidance is rather consistent in advertising two
primary risks. Increased rain chances Thursday afternoon and
night, and potential frost/freeze conditions Friday, Saturday, and
Sunday mornings.
Expected a dry Wednesday as a surface cold front begins to settle
southward into the area. There is a layer of mid-lvl moisture that
is hanging around the region, generally at or above 700 mb. Can a
sprinkle be ruled out? Probably not, but the chances are too low to
include at this time.
Medium range guidance has slowed down the arrival of deeper moisture
and larger scale lift expected to move across the region on
Thursday. Strong synoptic lift provided by mid-lvl shortwave energy
and a favorable upr jet structure, overtop increasing 700:600 mb
frontogenesis should produce increasing risk of light rain falls
through Thursday morning. The highest risks arrive Thursday
afternoon and evening as deformation rain band slides through the
CWA. Have bumped PoPs to likely levels (and these will likely
continue to climb), with the biggest uncertainty on the northwestern
edge of the rain band. Dry air intruding from the northwest will
make this a very sharp precipitation gradient. PoPs from Huron to
Chamberlain may be in a higher level of flux than normal.
The Friday-Sunday period will feature dry conditions, despite model
differences in the synoptic level features. The primary differences
fall with the progression of an upr trough through the region on
Friday. A sharper trough axis on the GFS pulls stronger high
pressure southeast, and results in less cloud cover and colder
nights. The ECMWF is slowly with the trough, more positively tilted
and results in a lingering of stratus through Saturday. The end
result is a large differential in daybreak sfc temperatures. This
will obviously impact any risk of frost or freeze at the end of the
week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 647 AM CDT Tue Oct 4 2016
West of HON/MHE/PKS areas ceilings 1-3k feet until 15z otherwise
vfr through 05/12z. East of this line Ceilings 3-6k feet variable
to 1-3k feet. Scattered shra/tsra...becoming numerous near and
east of BKX/FSD/YKN...with areas vsby 3-5sm. Conditions slowly
becoming vfr from the west 04/18z-05/03z over SD...and 05/03z-12z
over southwest MN and northwest IA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
SHORT TERM...
LONG TERM...Dux
AVIATION...
Area Forecast Discussion
National Weather Service Wilmington OH
1013 AM EDT Tue Oct 4 2016
.SYNOPSIS...
High pressure centered to the northeast will keep dry weather
over the region today through Friday. Above normal temperatures
are forecast to persist in the southerly flow around the high.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A couple of areas of AC developed across srn locations early this
morning. Most models did not anticipate this, however I did find
some H7 moisture on the HRRR which is in the correct location. The
HRRR lifts this moisture north, while gradually mixing it out, so
followed that scenario for today.
Previous forecast temperatures in the upper 70s still look good.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
In general, surface high pressure and a dry airmass will stay
centered near New England through Thursday while the upper ridge
axis translates eastward a bit and flattens in response to a
potent upper low far to the northwest.
After another mostly clear and dry night tonight, a weakening
frontal boundary will be moving toward the area Wednesday from the
west before dissipating on Thursday. Went with a dry forecast
Wednesday, though humidity and clouds will increase and a few
sprinkles over western locations cannot be ruled out. Thursday
should be free from precip under a renewed surge of dry air from
the south.
Warm weather will continue with highs reaching 80 in most
locations. Normal highs are around 70.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Upper ridge influencing the region at the beginning of the period
will get shunted east as Matthew moves north along the south Atlantic
coast and a short wave approaches from the west. Continuing
uncertainty with Matthew has a ripple effect into the Ohio Valley.
12Z models have slowed the progression of the short wave and
associated cold front. So it now appears that the front will cross
the region on Saturday with some showers along and behind the front.
High pressure will build in Sunday and Monday with temperatures at
or slightly below normal.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
Surface high pressure centered over the eastern Great Lakes
will provide dry weather conditions through the forecast period.
Although skies were clear with light winds, slightly drier air
mitigated the develop of widespread fog. Fog only developed at
KLUK valley location.
The fog will improve quickly after sunrise. After some early mid
level clouds, expect only few to sct cumulus clouds with some
thin high level clouds through the afternoon. Light east winds
early will become southeast at less than 10 kts during the day.
Fog development is likely again tonight at KLUK. Have a mention of
MVFR vsby restriction after 04Z.
OUTLOOK...No significant weather is expected.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Coniglio
NEAR TERM...Sites
SHORT TERM...Coniglio
LONG TERM...
AVIATION...AR
Area Forecast Discussion
National Weather Service Lubbock TX
631 AM CDT TUE OCT 4 2016
.AVIATION...
Shower chances appear to have cleared the area to the east with
mostly VFR the rule. However, still enough shallow moisture on the
Caprock where we are experiencing small dewpoint depressions and
satellite indicating probably fog forming right now from near
Littlefield towards Plainview. Added scattered low cloud and light
visibility restriction at KPVW, and also for KLBB as latest HRRR
runs have indicated potential for fog forming near or just
southwest of KLBB as well in the next hour or two. Westerly
breezes expected to kick in by 14z-15z and scour the low level
moisture off to the east. Solutions still showing only modest
winds today, on the order of 18 knots plus or minus at TAF sites
before winds taper early this evening. RMcQueen
&&
.UPDATE...
Added mention of patchy fog on the caprock through 15z. RMcQueen
&&
.PREV DISCUSSION... /issued 341 AM CDT TUE OCT 4 2016/
SHORT TERM...
Upper level low pressure continues to spin out to our north through
the northern and central high plains early this morning, with an
extension of mid and upper level vorticity advection currently
crossing the Texas panhandle and northern South Plains. Shower
activity has developed within a zone of deep layer subsidence over
the Rolling Plains and on track to exit the area by daybreak. But
given the passage yet of the vorticity lobe we will allow a very low
mention of thunder to linger across the eastern part of the Rolling
Plains until 15z. From then, the convergence on the east side of the
surface trough will be and should remain east of our area so
additional shower prospects will have dwindled further.
Up on the Caprock, we will see the onset of downslope westerly
breezes on the order of 20-23 knots across northern areas and 15-20
knots over southern areas. Passage of a Pacific Cold front should
not necessarily bring noticable cooling, with the downslope offset,
very dry replacement airmass, and full sunshine. We continue to
forecast highs today around 5-10 degrees above normal. Tonight will
continue the dry trend with veered low level flow holding on for the
most part, perhaps shallow moisture recovery over the southern part
of the Rolling Plains late tonight. But a weaker surface pressure
gradient should let winds lie down mostly under 10 mph later
tonight, facilitating a decent diurnal temperature drop. Favoring
slightly lower than guidance tonight. RMcQueen
LONG TERM...
Models are still suffering from the same inconsistencies as
yesterday making the long term forecast uncertain by the weekend.
Until the weekend, models do agree in pulling back low level
moisture into at least the Rolling Plains on Wednesday in response
to another long wave trough moving across the Rockies. Whether we
will see measurable precipitation out of this moisture is not
clear in model guidance. There will be some upper level diffluence
overhead on the south side of an upper level jet streak. Without
much more large scale lifting, there may be little development
from late Wednesday through early Thursday. The main differences
in the models is the degree of sharpness in the upper wave on
Thursday with the GFS and NAM being quite a bit sharper than the
ECMWF. The latest ECMWF model has come in a little sharper but not
nearly to the degree of the GFS/NAM. Better chances of
precipitation may exist Thursday night as we are closer to the
upper level entrance region. Furthermore, we will see added lift
from a strong cold front that will move through.
The sharpness of the trough will have effects on the
aforementioned front. A stronger cold front advertised by the GFS
will allow the lower atmosphere to dry out much more quickly on
Friday shutting down precipitation chances. Therefore, the ECMWF
does not dry out the lower atmosphere as much with a much weaker
surface ridge. Also, the ECMWF is not as cold as the GFS post
frontal with the weaker surface ridging. If we do see the stronger
surface ridging shown by the GFS, temperatures could easily drop
into the 30s on Saturday morning.
The next short wave will strengthen as it moves on shore in
western Mexico this weekend but then weaken as it moves across the
southwestern US. Moisture availability is in question all tied to
the strength of the front. The GFS would not likely leave enough
time for the atmosphere to recover moisture to introduce
precipitation early next week while the ECMWF would allow more low
level moisture to stream into the region.
&&
.LUB Watches/Warnings/Advisories...
None.
&&
$$
05/99/05
Area Forecast Discussion
National Weather Service Marquette MI
729 AM EDT Tue Oct 4 2016
.SHORT TERM...(Today and tonight)
Issued at 433 AM EDT TUE OCT 4 2016
Water vapor imagery and RAP analysis show a trof over the Rockies
with a vigorous shortwave over se MT and a downstream ridge over the
Great Lakes. Ahead of the trof and its associated cold front,
shra/tsra are lined up from the eastern Dakotas/western MN to the
southern plains. Closer to home, with the Upper Lakes now in the the
southerly flow btwn the Plains cold front and high pres centered in
the vcnty of northern ME, low level moisture that was over Lower MI,
IN, IL 24hrs ago has advected into the fcst area. Added
warmth/moisture from Lake MI and upsloping is further aiding the
cloud expansion early this morning. So far, not much in the way of
fog has been indicated at obs sites, but cigs are falling in central
Upper Michigan where upsloping is strongest.
With dwpts in the upper 50s at KMNM/KESC/KISQ and sse flow advecting
these higher dwpts upslope into areas where current temps are in the
low/mid 50s, cigs should continue to lower this morning, and may yet
see fog and perhaps some patchy -dz develop. This is most likely to
occur in central Upper MI where upsloping is more pronounced.
Otherwise, it appears quite a bit of cloud cover will mostly prevail
today given upstream cloud cover per satellite imagery. Areas that
see downsloping under southerly winds will have the best shot at
seeing more sun than clouds today. Despite less sunshine today, max
temps will be similar to yesterday due to the mild start to the day,
mostly mid 60s to 70F.
Tonight, the vigorous shortwave now over se MT will drift ne to the
ND/Saskatchewan border while a shortwave trof pivots ne thru the
Plains toward the Upper Mississippi valley. This shortwave trof will
help to propel cold front to ne MN/western WI by 12z Wed. With
excellent multi-model agreement on timing pcpn associated with
shortwave/cold front, including the 10 member NCAR ensembles, there
is little reason to deviate from that guidance. Fcst will show schc
to low chc pops reaching only western Gogebic County/far western
Ontonagon county 10-11z. Tight pres gradient/southerly winds and
precipitable water of 0.8 to 1 inch will lead to an unseasonably
warm night for early Oct. Min temps in the mid 50s to around 60F
will be around 20 degrees above normal and will be more typical of
normal max temps at this time of year.
.LONG TERM...(Wednesday through Monday)
Issued at 357 AM EDT TUE OCT 4 2016
A vigorous shrtwv/sfc lo pres lifting ne fm the Plains into scentral
Canada wl drag a weak cold fnt acrs the Upr Lks on Wed, accompanied
by a band of showers. Although there wl be a drying trend on Wed ngt
into Thu behind the fropa, another disturbance/lo pres lifting newd
within the larger scale sw flow alf btwn a rdg over the se CONUS and
troffing over the w wl bring another round of showers Thu ngt into
Fri. Temps wl remain above normal until Fri when much cooler air wl
arrive behind the cold fnt attendant to the exiting lo pres in
Ontario. The arrival of this cooler air behind the lo pres could
cause some lk effect showers Fri ngt into Sat ngt before hi pres
blds into the area later in the weekend and causes a drying trend.
Warmer air wl return early week once this trailing hi pres shifts to
the e and there is a wshft to the sw.
Wed...Deep shrtwv/lo pres over far sw Manitoba on Wed mrng are fcst
to move slowly to the ne thru the day. The attendant weak cold
fnt/warm conveyor belt mstr ribbon/axis of deep lyr qvector cnvgc wl
cross the Upr Lks on Wed accompanied by a band of showers/perhaps a
TS. Even though pwat near 1.50 inches wl be 200-250 pct of normal,
passage of the stronger shrtwv/forcing well to the nw and quick
moving fnt/warm conveyor belt wl limit pcpn totals. Vigorous deep
lyr drying/qvector dvgc in the wake of the fropa wl end the pcpn and
even allow a return of some sunshine by late in the day over the w.
Since the airmass following the fropa wl be Pacific in origon under
a sw flow aloft btwn the lingering wrn trof and the persistent upr
rdg over the se CONUS, max temps into the 60s up to 70 wl remain
above normal.
Wed ngt...Weak rdg of hi pres/mid lvl dry air following the fropa wl
bring a period of dry wx. But with h85 temps falling no lower than
8C over the w, temps wl remain above normal despite expected clr-
pcldy skies. A steady wsw wind wl further limit the diurnal temp
drop, especially over the w where a sharper pres gradient is fcst to
prevail.
Thu...Most of the models indicate Thu wl be a dry day despite some
incrsg clds in the sw flow alf to the ne of a shrtwv/dvlpg lo pres
in the central Plains. Some recent models, including the 18Z GFS and
12Z ECMWF, have hinted a weak shrtwv riding newd along the stalled
fnt just to the se of Upr MI could cause some showers over the se
cwa, so wl retain some lo chc pops in that area as this scenario is
not unreasonable considering the persistent hi amplitude upr rdg
over the se CONUS and sw flow alf. Even if there are more clds over
the se that would limit the diurnal temp rise there, fcst h85 temps
btwn 10C over the w and 12C over the e indicate another unseasonably
warm day is in store. If and where there is more sunshine, temps
could rise aoa 70.
Thu ngt/Fri...Models are in fairly good agreement showing the Plains
shrtwv/lo pres riding newd within the sw flow alf thru the Upr Lks
on Thu ngt and into Ontario on Fri. A period of vigorous dpva/deep
lyr qvector cnvgc/upr dvgc with pwat aoa 1.50 inch wl support hi
likely/categorical pops and some mdt rain/perhaps a TS over mainly
the se cwa before mid lvl subsidence/ drying in the wake of the
shrtwv/lo pres lifting to the ne and passing attendant cold fnt
diminish the pops w-e on Fri. Recent GFS runs have been slower to
push the cold fnt too far to the e and thus end the pcpn over the se
cwa under a more ssw flow alf, not unreasonable considering the hi
amplitude upr rdg over the se CONUS that would tend to slow the ewd
progression of the deep drying. Fri wl be a much cooler day as h85
temps are fcst to fall to arnd -1C over the w toward 00Z Sat behind
the fropa.
Extended...After some initial drying under a more acyc nw flow into
Fri ngt in the wake of the exiting lo to the ne, the arrival of
colder air/h85 temps as lo as -3 to -4C on Fri ngt/Sat and aprch of
another shrtwv/some deeper mstr fm the w on Sat, a period of lk
effect showers wl be psbl and focused on a lk induced trof that some
of the models dvlp over the relatively warm waters of Lk Sup on Sat.
While the fcst h85 temps sug some snow could mix with the pcpn over
mainly the hier terrain of the nw cwa, fcst unstable llvl lapse
rates/warmer sfc temps indicate this ptype is too unlikely to
include in the fcst attm. The arrival of hgt rises/more acyc flow in
the wake of the passing shrtwv on Sat ngt/Sun wl diminish the lk
effect pcpn. However, some of the longer range models maintain lower
hgts and show another shrtwv aprchg on Sun that would bring more
clds and some sct showers. But even these models show rising hgts/
more acyc flow arriving on Mon that would support a drying trend
early next week. As the hi shifts to the e on Tue, a return sw flow
wl bring a return of warmer air. Since some of the guidance has
shown a cold fnt wl aprch on Tue, the fcst wl include a lo chc of
some showers on Tue.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 729 AM EDT TUE OCT 4 2016
An upslope southerly flow of moist air should lead to prevailing
MVFR cigs at KSAW today. While downslope component to the flow at
KIWD will result in VFR conditions, some brief periods of MVFR cigs
should occur this morning before daytime heating works to raise
cloud bases/mix moisture out. At KCMX, downslope flow off the Huron
Mountains should allow VFR conditions to prevail today. VFR
conditions are expected at all 3 terminals tonight. LLWS is
possible, most likely at KIWD, as winds strengthen above inversion.
&&
.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 433 AM EDT TUE OCT 4 2016
SE to S winds will generally be on a gradual increase thru Wed
morning as a cold front approaches from the west. Winds will become
strongest over central and eastern Lake Superior, reaching the 20-
30kt range late tonight/Wed. The cold front will sweep across Lake
Superior Wed aftn/evening. While SW winds as high as 15-25kt should
occur behind the front Wed night into Thu morning, strongest between
Isle Royale and the Keweenaw Peninsula, the pressure gradient and
winds will weaken for a time Thu aftn and night as a low pressure
trough develops over the Upper Lakes ahead of a low pressure wave
developing over the southern Plains. After this low pressure wave
passes late Thu night/early Fri morning, NW winds up to 20-25kt will
develop on Fri, strongest over the e half of Lake Superior. NW winds
up to 20kt will linger on Sat.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...KC
AVIATION...Rolfson
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Raleigh NC
1120 AM EDT TUE OCT 4 2016
.SYNOPSIS...
Cool high pressure will build down the East Coast into the Carolinas
through Thursday. Hurricane Matthew is expected to tracking
northeastward along the coast of the Carolinas Friday night through
Saturday night.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1120 AM Tuesday...
Forecast is on track. Cool surface high pressure centered over the
Canadian Maritimes will continue to extend SW into the Carolinas, as
weak inverted troughing sits just off the coast. The latest RAP
indicated that a few coastal showers could work westward into the
eastern Coastal Plain, however this doesn`t have support from other
CAMs nor large scale models, so will keep it dry but with
considerable cloud cover from Highway 1 eastward, along the axis of
the upper jet tail. Temps so far are trending fairly close to
forecast highs, so only minor tweaks made, 75-81. -GIH
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 307 AM Tuesday...
Surface high pressure remains across the area as upper level ridging
builds over the east coast. Shallow low level moisture will return
early Wednesday in northeasterly flow, underneath dry mid levels.
Morning stratus will lift in the afternoon, but mostly cloudy
conditions will persist through most of the day. Highs a few degrees
cooler, in the lower to mid 70s.
Low stratus will redevelop overnight Wednesday. Lows upper 50s to
lower 60s.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 335 AM TUESDAY...
...Track of Matthew will play a role in our weather conditions early
in the weekend...
An area of high pressure at the surface and aloft will maintain a
stable atmosphere across central NC Thursday and Thursday night. Due
to the orientation of the low level high (sw-ne from southern New
England-southern Appalachians)the flow around this system will
maintain a supply of Atlantic moisture over central NC, resulting in
areas of stratocu. These patchy low clouds will be more prevalent
over the east sections of our forecast region versus the west-nw.
Any precipitation that occurs will be light and very spotty, with
expected coverage less than 15 percent as moisture depth appears too
shallow to support any showers.
The low level northeast flow will maintain a seasonably cool air
mass. Highs Thursday low-mid 70s.
Latest model guidance continues to shift the track of Hurricane
Matthew further to west, and closer to Southeast U.S. coast. The
eventual track of Matthew will depend upon two elements: 1.) the
strength of the upper level ridge to its north; and 2.) the speed
and strength/amplitude of an upper level trough approaching from the
nw. While timing differences remain with the ECMWF still slower than
the GFS, the differences have narrowed compared to the last 24 hours.
Based on this current track, may see areas of rain associated with
Matthew begin to move into southern sections of central NC Friday
afternoon into Friday night.
The approach of the upper level trough will play a role in Matthew
transitioning from a purely tropical system to an extratropical
system. During this transition, we normally see a band of heavier
precip develop to the nw of the center. Based on the model trend,
this band of heavier precip may develop over sections of central NC,
possibly as far west as the nw Piedmont. Will increase PoPs from
previous forecast Friday night-Saturday night, but refrain from
increasing PoPs to likely over the southeast half of central NC
since we have plenty of time to increase PoPs based on future model
runs. In addition, have increased nly winds late Friday through
Saturday night with the apparent closer approach of Matthew, with
the main adjustment over sections of the Sandhills and the Coastal
Plain.
Expect Matthew to lift off to our northeast Sunday into Monday with
improving weather conditions. North to northwest flow behind the
departing system will advect a notably cooler air mass. High temps
Monday may be as much as 5-6 degrees cooler than normal.
For the most up to date info on Matthew please refer to the National
Hurricane Center website at http://www.nhc.noaa.gov.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
As of 733 AM Tuesday...
Sub-VFR vsbys will improve over the next few hours. High confidence
in VFR conditions thereafter through 00z Wednesday across the area
as high pressure extends in to the Carolinas from the north.
Stratus development is likely with increasing moisture in low level
northeasterly flow late Tuesday night/early Wednesday and again
Wednesday night/Thursday morning. A period of adverse aviation
conditions is possible this weekend depending on the track of TC
Matthew.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Hartfield
NEAR TERM...Hartfield
SHORT TERM...30
LONG TERM...WSS
AVIATION...30
Area Forecast Discussion
National Weather Service Albany NY
420 PM EDT Tue Oct 4 2016
.SYNOPSIS...
Mostly cloudy skies will gradually give way to more
breaks this evening as an upper level storm moves away from the
area. High pressure will then move over the region over the next few
days, allowing for dry conditions with temperatures moderating above
normal through Friday. Hurricane Matthew may impact the eastern
seaboard this weekend and its effects, if any, on eastern New York
and western New England are still unknown at this time.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 420 PM EDT...An upper level low continue to be situated
just east of the region near the coast of southern New England.
This is the same storm system that has been impacting our region
over the past week, and its finally starting to slide eastward and
lose its influence on our area. Upper level ridging is now
building over the area, with rising heights and temps aloft.
Although both water vapor imagery and the 18z KALY sounding shows
plenty of dry air in place at mid levels, there remains lots of
low stratus clouds over the area. This is thanks to some low level
moisture trapped beneath a strong inversion at 725 mb, which is
very evident on the recent sounding as well. The low-level
moisture has been supplemented by a weak easterly flow at low
levels off the western Atlantic Ocean, which has resulted in
mostly cloudy skies over much of the region.
As the upper level low continue to move away tonight, clouds
should start to break up tonight as drier air starts to move into
the region. Model soundings and 3km HRRR guidance all suggest sky
cover will improve to partly cloudy to mostly clear by later
tonight. With the clearing skies, light winds and lingering low-
level moisture, some patchy fog may develop in some spots, such as
in valleys and near bodies of water.
Overnight lows will be cooler than recent nights due to the
clearing skies. Most areas look to fall into mid to upper 40s
tonight.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Dry and quiet weather with warming temperatures is expected
during the entire short-term period.
Surface high pressure will be anchored over New England with
warming temps aloft and upper level ridging in place. 850 hpa
temps will warm from near +7 degrees C on Wednesday to as warm as
+13 C on Friday. Plenty of sunshine is expected each day with
clear skies at night. Some patchy fog is possible each night thanks
to the good radiational cooling in place.
High temps look to reach into the upper 60s to low 70s on
Wednesday, mid 70s on Thursday and mid to possibly upper 70s on
Friday. Overnight lows for Wednesday and Thursday nights look to
be in the 40s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The main forecast challenge in the long term period is where
Hurricane Matthew tracks and if it has any impact or influence on
our weather over the weekend.
Model guidance has shifted dramatically this afternoon with the
latest 12z guidance. Several major models (ECMWF, GFS, and GGEM)
and the 12z GEFS mean have all shifted with their track on the
storm. The latest GFS/GGEM/GEFS all are further east with the
storm as it reaches off the Northeast coast this weekend, while
the latest ECMWF keeps the storm spinning off the coast of the
Southeast. All of this is related to how the hurricane interacts
with a shortwave trough (and associated cold front) which moves
from the Great Lakes towards the Northeast this weekend. All of
this uncertainty within the guidance and run-to-run inconsistency
lowers the confidence on the current forecast.
For now, we have gone with a dry forecast for Friday night with
lows falling into the 40s. Over the weekend, we are currently
going with chc pops for rain showers. Even if Matthew stays
south/east, there will be chance for some rain as the northern
stream cold front moves across the area. If some tropical moisture
is able to get pulled northward, there could be some locally
heavier rainfall along or ahead of the front thanks to higher
PWAT air, otherwise, it could be just some typical frontal
showers. If the latest models are all wrong and the earlier runs
are more correct (such as yesterdays or last night`s runs), there
could be a more direct impact of the storm passing closer to the
area with more significant rainfall and wind. At this point, its
too early to pin down specifics, so we recommend to keep up with
the latest local forecasts and latest advisories from the
National Hurricane Center, which are updated every 6 hours on
their website: www.hurricanes.gov
With the current forcast for expected clouds and precip, temps
look a little cooler on Saturday with highs in the 60s. Behind
the departing cold front (and possibly coastal storm), it looks
even cooler for Sunday with highs in the low 50s to low 60s, with
clouds eventually breaking for some sunshine.
By early next week, it looks dry and cool for Monday (Columbus
Day) with high pressure nearby. High temps may only be in the 50s
with a mix of sun and clouds. Another cold front may be moving
towards the area for Tuesday with another chance for rain showers
and some passing clouds. Highs once again look in the 50s to low
60s for Tuesday.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
Clouds continue to linger across the area as moisture is trapped
under an inversion. Cloud cover is expected to gradually erode as
drier air works in with mostly clear skies developing this evening.
With clear skies and calm winds radiational fog is expected to
form. IFR conditions are expected to develop at KGFL and KPSF. The
fog will lift and burn off after sunrise with a clear day on tap
for Wednesday with ridging over region at all levels of the
atmosphere.
Outlook...
Wednesday Night through Friday Night: No Operational Impact. NO
SIG WX.
Saturday through Sunday: Moderate Operational Impact. Chance of
SHRA.
&&
.FIRE WEATHER...
RH values will be near 100 percent tonight with some dew and fog
formation. Wind will be very light or calm tonight. Clouds will
gradually break up overnight, but no precipiation is expected.
During the day tomorrow and Thursday, it will continue to be dry
with a partly to mostly sunny sky. RH values will fall to 40 to
55 percent with light and variable winds.
The next chance for a wetting rainfall may be this weekend.
&&
.HYDROLOGY...
The latest US Drought Monitor continues to show drought
conditions across much of the region. Precipitation departures
this calendar year have been 3 to 12 inches below normal, with the
greatest departures across southeastern parts of the HSA. As a
result, streamflow and ground water levels have been running below
normal.
High pressure will dominate the weather through Friday with dry
conditions and no precipitation. This will allow rivers and
streams to hold steady through much of the week.
The next system to watch will be Hurricane Matthew, which is
currently in the Caribbean Sea. It looks to track north off the
coast of Florida over the next few days and eventually northeast
off the eastern seaboard. It is still too early to say if this
storm will have any direct impact on the HSA. If there was to be
any impact, it would be over the weekend. Even without Matthew
directly impacting the area, a cold front may bring some showers
to the region for Saturday into Sunday, although the amounts of
rainfall with this front will also depend on the track of the
tropical system.
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...Frugis
NEAR TERM...Frugis
SHORT TERM...Frugis
LONG TERM...Frugis
AVIATION...IAA
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service Dodge City KS
314 PM CDT TUE OCT 4 2016
.UPDATE...
Issued at 315 PM CDT Tue Oct 4 2016
In coordination with the frost/freeze advisories from Goodland and
Pueblo, issued a frost advisory for Hamilton county late tonight
and early Wednesday.
Severe potential is fading quickly across the SE zones. A storm is
still briefly possible across eastern Barber county over the next
hour, otherwise all zones dry through tonight.
&&
.SHORT TERM...(This evening through Tonight)
Issued at 1215 PM CDT Tue Oct 4 2016
Cold front has cleared much of the DDC CWA early this afternoon,
with gusty NW winds and cool/dry advection. Visible satellite
indicates agitated cumulus in the remaining warm sector across the
SE zones. Still a south wind at Medicine Lodge, so convergence on
the advancing boundary is substantial. Thunderstorms may still get
going for an hour or two near Medicine Lodge in a moderate
CAPE/shear enviroment. Widespread severe weather is expected to
remain in Wichita`s CWA through this evening. A clear sky expected
overnight across SW KS with light and variable winds. A wide range
in low temperatures at sunrise Wednesday, ranging from the mid 30s
in Hamilton county to the mid 50s in Barber county.
.LONG TERM...(Wednesday through Tuesday)
Issued at 130 PM CDT Tue Oct 4 2016
Wednesday...Sunny, warm and dry. Light SW winds under moderate
SW flow aloft. Highs ranging from the mid 70s NW to the mid 80s
SE.
Moderately strong shortwave trough over the Great Basin Thursday
morning phases into NW Kansas early Friday morning per the GFS,
with the 12z ECMWF offering a more progressive timing. Regardless
of the model, this synoptic pattern will result in cool
anticyclogeneis across the plains, and a stout cold frontal
passage during the Thursday timeframe. GFS forecasts some
convection along the advancing frontal boundary across the
SE zones Thursday afternoon/evening. Moisture will be rather
limited, but agree with SPC Day 3 outlook suggesting a marginal
risk for severe wind/hail across roughly the SE 1/4 of the CWA.
Otherwise, strong gusty north winds will spread over SW KS
Thursday and Thursday night. A tight temperature gradient Thursday
afternoon, ranging from the upper 60s NW to the mid 80s SE.
Surface high will be entering NW Kansas Friday morning, with
cooler low temperatures in the 30s and 40s. Much cooler Friday,
with highs in the 60s despite full sunshine. With the surface high
sliding SE and placed over SW KS, Saturday morning will offer the
coldest readings of the forecast period, with MEX guidance well
down into the 30s. Frost advisories may be necessary Saturday
morning.
Saturday through Monday...Afternoon temperatures moderate, with
continued dry weather.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1200 PM Tue Oct 4 2016
VFR through Wednesday. NW surface winds at all airports this
afternoon behind the exiting cold front. NW winds will diminish
through late afternoon. HRRR model runs develop TSRA well east of
HYS around 20z, so removed the VCTS mention in the HYS TAF.
SKC expected overnight with light and variable surface winds.
Light SW winds resume at all airports after 15z Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 82 52 79 / 0 0 0 10
GCK 41 80 46 74 / 0 0 0 0
EHA 42 79 47 75 / 0 0 0 0
LBL 43 82 48 79 / 0 0 0 0
HYS 45 78 52 70 / 0 0 10 10
P28 55 84 61 85 / 10 0 20 30
&&
.DDC Watches/Warnings/Advisories...
Frost Advisory from 3 AM to 8 AM MDT Wednesday for KSZ061.
&&
$$
UPDATE...Turner
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Turner
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
358 PM PDT TUE OCT 4 2016
.SYNOPSIS...A few light showers are possible through Wednesday
for locations generally north and west of a Leggett to Weaverville
line. High pressure will build across the region for Thursday
through the weekend. Rain chances will return to the region early
next week, as our next system approaches the area.
&&
.DISCUSSION...Rain chances remain for the next 24 hours, before
drier conditions return to the region. A few light rain showers
continue to develop across Del Norte and Humboldt counties, and
the adjacent coastal waters. They have been very small and
isolated so far, but we do expect an increase in coverage and
intensity overnight as another vort max dives southeast in the
flow aloft. Increased ascent with this feature will allow POPs to
remain the chance category or higher for these areas. Rainfall
amounts of 1/10 to 1/4 of an inch are possible nort of an Orick to
Orleans line, with amounts gradually tapering off the farther
south and east one goes.
A ridge of high pressure building across the region will put an end
to our rain chances for Thursday through the weekend, with decreased
cloud cover allowing afternoon temperatures to climb back into the
80s across the interior, with seasonal temperatures continuing near
the coast. Overnight lows will remain near seasonal values, with
upper 30s to mid 40s across the interior expected, warming to near
50 degrees closer to the coast.
Our next system of interest looks to approach northwestern
California early next week. Model consensus remains good with the
timing, track, and precipitation forecasts amongst the long range
models. The general theme is for southerly winds to develop during
the day Monday, with an increase in mid and upper-level moisture.
Rain chances will likely return to a large portion of the region,
just beyond the current forecast range. /PD
&&
.AVIATION...Convective cloudiness is several miles inland this
afternoon, leaving coastal locations mostly clear. However, low
clouds at about 3500 ft are moving SE from the Pacific and have
just made it into KCEC. Mostly VFR conditions are expected to
continue until later this evening when some MVFR ceilings are
possible along the Redwood Coast. Later tonight, both the HRRR and
NAM are indicating 2 distinct batches of light showers moving
inland along the Redwood Coast. These will mainly affect KCEC.
KUKI is expected to remain mostly VFR. /SEC
&&
.MARINE...As expected, generally light split surface flow has
developed across the coastal waters with SW winds N of Cape
Mendocino and NW winds S of the cape. However, NW swell at around 11
seconds is a foot or two higher than initially forecast, and this
already brings seas in the N waters already to advisory criteria. As
a result, issued the 3 PM package a bit early in order to include
that headline. There may be a brief period later tonight when seas
in the near shore portion drop below advisory criteria before another
batch of swell at a slightly higher period enters the area. However,
there is enough uncertainty to warrant keeping the advisory up
through Wednesday night. Have extended the S offshore advisory into
Friday. Initially, this advisory will be for seas, but winds will
increase to low end advisory criteria by Thursday. N winds are
expected to subside a bit as we head into the upcoming weekend.
/SEC
&&
.EKA Watches/Warnings/Advisories...
CA...None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 3 AM Thursday for PZZ450-470.
Small Craft Advisory from 9 AM Wednesday to 3 PM Friday
for PZZ475.
$$
Visit us at http://www.weather.gov/eureka
Follow us on Facebook and Twitter at:
http://www.facebook.com/NWSEureka
http://www.twitter.com/nwseureka
For forecast zone information
see the forecast zone map online:
http://www.weather.gov/eureka/zonemap.png
Area Forecast Discussion
National Weather Service Grand Forks ND
335 PM CDT Tue Oct 4 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 335 PM CDT Tue Oct 4 2016
Placement of precipitation as well as strength will be the main
challenges for the period.
The upper low will continue to lift northeast across the Northern
Rockies and Northern Plains. The first round of precip is entering
southeastern ND and west central MN as a lead shortwave is
rotating through and the surface cold front approaches. The HRRR
has been doing a decent job with the current convection and they
continue to have the band of rain lifting north along the RRV late
this afternoon. It then shifts the main rain area eastward into
MN, which makes sense as a more significant shortwave currently
over western SD/Neb lifts northeast and the cold front pushes
through. Current elevated CAPE values are around 500 J/kg and this
is not expected to change too much. Deep layer bulk shear values
are around 40-50 kts, and as the low level jet kicks in over the
eastern forecast area this evening some intensification of storms
is possible. However, think the greatest threat will be heavy
rainfall as the rain trains northward and some areas in the
southeastern counties could see over an inch of accumulation.
The upper low will continue to slowly move over the Northern
Plains and southern Canada tomorrow. With the front pushed most of
the way through think the overnight showers will be pushing off
through the northeastern counties at daybreak. However, wrap
around showers will begin to enter the northwestern counties by
late in the day. Temperatures will be much much cooler with highs
mainly in the 50s and some spots staying in the upper 40s.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 335 PM CDT Tue Oct 4 2016
No major precipitation chances throughout the period as winds and
frost/freeze potential will be the main concerns.
The period begins with an upper low continuing to spin across
southern Saskatchewan/Manitoba before it finally begins to propagate
off towards Hudson Bay. The associated trough will be slow to pull
away from the area so a few lingering rain/snow showers near the
international border, along with gusty west/northwesterly winds,
will persist as the trough pulls away and weak upper ridging builds
in. Cool surface high pressure building into the Northern Plains by
late in the week will keep conditions dry heading into the weekend
before northwest upper flow returns.
Below normal temperatures will persist for the first half of the
period with highs struggling to get into the 50s. Thursday night
will bring the first chance of a hard freeze to the Devils Lake
basin with chances spreading south and eastward for an even colder
Friday night. Did go a few degrees lower than guidance for Friday
night with the surface high passing directly over the area. Warmer
air will return late in the weekend and early next week with highs
back into the 50s/lower 60s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1235 PM CDT Tue Oct 4 2016
Clouds over the region have brought MVFR to low VFR ceilings for
most of the TAF sites. KDVL is down to IFR, but expecting ceilings
to come up at that site in the next hour or two to MVFR. Showers
and thunderstorms will move up from the south, impacting the Red
River Valley TAF sites this afternoon and evening with sites
further east seeing more activity later tonight. Instability is
better further south and east so kept TS mention at KFAR, KTVF,
and KBJI. There should be some recovery to VFR conditions for a
time period late tonight and into tomorrow morning as drier air
moves in from the southwest. More MVFR ceilings will arrive at
KDVL just before the end of the TAF period as lower clouds start
to move back in later tomorrow. Southeasterly winds will remain
rather breezy today with gusts in the 25 to 30 kt range, but there
should be some decrease this evening as the center of low pressure
approaches. Winds will pick up again late tomorrow morning from
the southwest with gusts again above 20 kts.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
SHORT TERM...JR
LONG TERM...Lee
AVIATION...JR
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
315 PM CDT Tue Oct 4 2016
.SHORT TERM...
255 PM CDT
Tonight...
Slow and perhaps just partial clearing of the overcast ceilings
will allow temperatures to fall into the lower 60s but
persistent southeasterly flow will keep lows considerably warmer
than average for early October. Precip chances increase from west
to east toward daybreak as an upper trough swings toward the area
ahead of the large low pressure system positioned across the
Northern Plains. The best moisture transport appears to be focused
west of the area closer to the surface boundary, so have only
carried chance to slight chances of rain locally.
Lenning
&&
.LONG TERM...
313 PM CDT
Wednesday through Tuesday...
A challenging latter half of the week presents itself with rain
chances Wednesday-Friday, including some thunder potential within
that, but definitely not a washout through that entire period. In
fact, temperatures look to be above to well above normal if some
sun can be realized, before a drop into the weekend.
The upper air pattern remains amplified and blocked on Wednesday
and Thursday, with a broad and baggy yet strong upper trough
across the western half of the U.S., and an anomalous ridge
across the east. Within the western trough, a couple potent waves
will be rotating through, one resulting in a deep surface low
across far southern Canada on Wednesday. An associated occluding
and weakening front will push east into the area Wednesday. Ahead
of this, a 40 kt low level jet and associated ribbon of moisture
transport forecast by the RAP and NAM will veer into northern
Illinois Wednesday morning. Convection expected tonight to our
west over Iowa will likely gradually weaken in the early morning
as the parent short wave translates more northeast, however
isolated to scattered showers, possibly with some storms, may
traverse across the CWA. A weak focus/confluence is left from the
dying front by Wednesday afternoon, and have maintained some low
chances of showers/storms east in the afternoon and evening, but
not particularly excited about those.
Temperatures on Wednesday are tricky with cloud cover potentially
playing a role. Have continued the gradual warming trend from
today and what is being observed upstream across southern Illinois
and Indiana (highs of 75 to 80).
The next short wave trough will round the base of the primary
upper low and move into the Central Plains by later Thursday. A
warm front is likely to lift north over the area on Thursday,
though it may be slowed/enhanced by quite a bit of morning clouds
as indicated by some guidance. The greater lift for rain is
focused to the northwest of the area given the forecast jet
placement, however moisture looks to steadily increase over the
local area with 60s dew points returning into the warm frontal
zone. So do have chances for showers and storms increasing, with
the highest chances in the northern and western CWA Thursday and
Thursday Night. The chance for stronger storms is non-zero but
depends on how deep and far east the low moves up the boundary.
Highs on Thursday could again vary quite a bit, but feeling more
confident of at least 80 being reached south of I-80 and possible
areawide.
For Friday and Friday Night, have continued to go with a blend of
the slower GFS and quicker EC with the cold frontal passage, as
can see equal chances of either at this time. Have a gut feeling a
slower solution than the EC will pan out given the ridge to the
east and even possibly to some degree the approach of Hurricane
Matthew, but unsure if as slow as the GFS. The slower the front
passes on Friday, the more likely it would be to have post-frontal
rain into Friday evening. Conditions behind the front should turn
breezy with temperatures dropping.
Highs on Saturday in northern locations still look to fall short
of 60 even with some differences in the models, and Saturday and
Sunday night both look cool. There could be some 30s in outlying
locations depending on just how cool the low-level air mass
remains as it spreads southeast.
MTF
&&
.AVIATION...
For the 18Z TAFs...
Midlevel VFR stratus has been anchored over the area for most of
the day but clearing is evident in locations south of the
terminals. However, with afternoon heating the development of
broken cumulus may delay a transition to higher ceilings until
late in the afternoon or early evening. These overcast skies also
are inhibiting gusts, though occasional speeds to around 15kt have
been seen in the 1-minute data. This relatively light
southeasterly flow will persist tonight before veering southerly
tomorrow and increasing a bit. Showers are possible toward the RFD
area early tomorrow, and perhaps in the Chicago terminals later in
the day.
Lenning
&&
.MARINE...
255 PM CDT
Relatively light southeasterly flow will gradually strengthen
overnight and turn more southerly. This will allow for a period of
greater wave growth tomorrow, especially across the north half.
Waves begin to subside again later tomorrow as winds relax
somewhat and veer more southwesterly. Friday night a frontal
passage will usher in cooler and stronger northwesterly winds.
Lenning
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Saint Louis MO
336 PM CDT TUE OCT 4 2016
.SHORT TERM... (Through Late Wednesday Afternoon)
Issued at 334 PM CDT Tue Oct 4 2016
Still expect this evening to be mainly dry across the area as
showers and thunderstorms are still out over eastern Kansas and
northwest Missouri. GFS and NAM are in good agreement that a deep
trough currently over High Plains will move northeast to near the
Mississippi River by 12Z tomorrow morning. The RAP shows low level
moisture convergence increasing over central Missouri by 06Z that
moves east towards the Mississippi River by 12Z. This will be under
mid-level ascent from the trough. Have gone with likely PoPs
overnight across central Missouri with likely and high chance PoPs
into southeast and east central Missouri as well and southwest
Illinois on Wednesday morning as the forcing begins to weaken and
move eastward. By Wednesday afternoon there will only be some weak
residual low level forcing across southeast Missouri into south
central Illinois. Will keep a chance of showers and thunderstorms
going over the southeast half of the CWA.
Stuck close to the GFS/NAM MOS guidance which matches up well
tonight and tomorrow.
Britt
.LONG TERM... (Wednesday Night through Next Tuesday)
Issued at 334 PM CDT Tue Oct 4 2016
The stacked low over south central Canada Wednesday night will
continue moving northeast. Mid and upper level parts of the system
will begin opening up which should help increase the forward speed
of the system Thursday night and Friday as it continues to lift.
The longwave pattern won`t change much with Hurricane Matthew
blocking things up. Therefore warm/moist southwest flow with a
decent chance of rain...primarily across central and northeast
Missouri and west central Illinois will continue Wednesday night
and Thursday.
Meanwhile another shortwave will move southeast across the Rockies
and dig into the base of the longwave trof. The GFS and NAM move
the longwave east more slowly since they amplify the pattern more
when the shortwave digs in. The ECMWF keeps the shortwave moving
rather than using that energy to amplify the pattern which results
in the cold front passing through our area early Friday morning
rather than Friday afternoon as the NAM and GFS show. Obviously the
slower GFS/NAM solution would mean a warmer Friday for most of the
area along with a greater chance for rain and thunderstorms. This
is more consistent with our current forecast and I would prefer to
see more consensus before changing Friday`s forecast from "warm and
wet" to "cooler and dry". The GFS keeps some lingering post-frontal
precip over the area. This looks to be in response to the passing
of the mid-upper level shortwave and all of its associated broad
scale lift. Think some light rain or sprinkles look plausible.
A 1029mb high comes roaring in Saturday behind the front which
will bring us temperatures as much as 15 to 20 degrees cooler than
Friday`s were. High pressure remains in control of the weather at
least through Monday. Some weak moisture return may cause a few
showers Monday night or Tuesday according to the ECMWF, but the
GFS is dry. Slight chance PoPs on ensemble guidance look like a
good compromise given the uncertainty. Saturday and Sunday look
seasonably cool, with gradual warming back to near or above normal
temperatures on Tuesday.
Carney
&&
.AVIATION... (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 117 PM CDT Tue Oct 4 2016
Expect dry and VFR conditions at the terminals through early
evening. Then showers and thunderstorms currently over eastern
Kansas will move into central and northeast Missouri and west
central Illinois late this evening and overnight. Coverage of the
of the showers and thunderstorms will be enough to include in a
PROB30 group overnight. Showers will be more scattered by the
time they move into the St. Louis area terminals, so have only
used a VCSH tomorrow morning. There is the possibility of MVFR
ceilings and visibilities with showers and thunderstorms.
SPECIFICS FOR KSTL: Expect mainly dry and VFR conditions through
most of tonight. Then scattered showers will move into the area
late tonight and Wednesday morning. There is the possibility of
MVFR ceilings with the showers.
Britt
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 67 82 67 86 / 20 50 20 20
Quincy 62 80 65 83 / 50 30 40 60
Columbia 61 81 66 83 / 60 30 40 50
Jefferson City 62 82 66 86 / 60 30 40 40
Salem 64 81 64 85 / 10 30 10 5
Farmington 62 80 64 84 / 10 50 5 5
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
336 PM EDT Tue Oct 4 2016
.SHORT TERM...(This evening through Wednesday)
Issued at 324 PM EDT TUE OCT 4 2016
Water vapor imagery and RAP analysis show a mid-upper level trough
over the Northern Plains with a vigorous shortwave over ern MT and a
downstream ridge over the Great Lakes. Ahead of the trough and its
associated cold front, there is an area of shra/tsra from eastern
ND/western IA as noted on regional radar imagery. Closer to home,
some light shra popped up over scntrl Upper Mi this morning and
lifted north into MQT county during the day, but it appears from
webcams that much of this pcpn has now ended.
Tonight, the vigorous shortwave now over se MT will drift ne to the
ND/Saskatchewan border while a shortwave trough pivots ne thru the
Plains toward the Upper Mississippi valley. This shortwave trough
will help propel the cold front to ne MN/western WI by 12z Wed.
Models generally still in good agreement on timing of pcpn
associated with shortwave/cold front, although the 12z GFS may be
slightly faster than the rest of the model guidance. Will continue
to carry schc to low chc pops reaching only western Gogebic
County/far western Ontonagon county 10-11z. Tight pres
gradient/southerly winds and precipitable water near 1 inch will
lead to an unseasonably warm night for early Oct. Min temps in the
mid 50s to around 60F will be around 20 degrees above normal and
will be more typical of normal max temps at this time of year. May
have a good chance of breaking record high minimum temperature of 54
for date (10/5) here at NWS MQT.
Wed...Deep shrtwv/low pres over far sw Manitoba on Wed morning are
fcst to move slowly to the ne thru the day. The attendant weak cold
front and deep moisture axis/deep layer q-vector convergence assoc
with the front wl cross the Upper Lakes on Wed accompanied by a band
of showers and perhaps a TS as MLCAPEs rise 200-300 j/kg. Even
though pwat near 1.50 inches wl be 200-250 pct of normal, passage of
the stronger shrtwv/forcing well to the nw and quick moving
front/and deep moisture axis wl limit pcpn totals. Vigorous deep
layer drying/q-vector divergence in the wake of the cold fropa wl
end the pcpn and even allow for a return of some sunshine by late in
the day over the w. Since the airmass following the fropa wl be
Pacific in origin under a sw flow aloft between the lingering wrn
trough and the persistent upper ridge over the se CONUS, expect max
temps to remain above normal...well into the 60s to lower 70s.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 335 PM EDT TUE OCT 4 2016
Deep trough over the western conus gradually moves to the central
Conus by Fri morning. Trough then slides across Great Lakes and
eastern Canada through the weekend as Hurricane Matthew rides along
the east coast. At the sfc, strong low pressure system southern
Manitoba to northern Ontario slides to northern Ontario and Hudson
Bay by Thu helping to push a cold front across the Upper Great
Lakes. Even though the front will be east of Upper Michigan on Thu
another shortwave lifting ahead of the larger trough may bring some
showers to Upper Michigan. Much better chance for rain arrives Thu
night into Fri morning as stronger shortwave and deepening low
pressure system lift across the Upper Great Lakes.
GFS keeps showers or stratiform rain into Fri evening in right
entrance region of jet streak while ECMWF is more aggressive in
moving the trough aloft through and the jet farther east. Latest GFS
is quicker than 06z run in bringing in drier weather for Fri night
though. Dry punch aloft forecast Thu night into Fri will lead to
steep lapse rates aloft and possible embedded thunder/heavier rain
rates.
Low and associated cold front move through and airmass in wake of
the front does look cooler than seen for a while as H85 temps fall
blo 0c. Expect daytime highs for the weekend to stay in the 50s
across Upper Michigan. Trough axis with deeper moisture and the cool
temps should support chances for lake effect rain showers with delta
t/s over 15c. Some hint that sfc trough may be over Lk Superior and
Upper Michigan later Sat into Sat night. Convergence from the sfc
trough and over-water instabiilty and depth of convective layer
suggest there may be waterspout potential for the weekend. Too
early to get those details in there yet though.
High pressure moves in later in the weekend, then another sfc trough
will move through on Mon. Larger scale forcing looks minimal so not
looking at a lot of rain. After a cool weekend, temps will rebound
back toward normal. Could see a couple cool nights Sat night or Sun
night as the high slides across the region.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 244 PM EDT TUE OCT 4 2016
An upslope southerly flow of moist air led to a period of lower
stratus clouds and showers at SAW this afternoon, but now cigs are
lifting from MVFR toward VFR at KSAW. Expect VFR conditions to
continue at all 3 terminals through much of tonight, but then cigs
will begin to lower toward MVFR late tonight into Wed morning with
advance of frontal system and associated band of showers from Plains.
LLWS is possible late tonight, most likely at KIWD, as winds
strengthen above inversion. However, expect gusty enough southerly
winds at sfc to preclude a mention of LLWS.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 324 PM EDT TUE OCT 4 2016
SE to S winds less than 20 knots will generally be on a gradual
increase late tonight thru Wed morning as a cold front approaches
from the west. Winds will become strongest over north central and
eastern Lake Superior, reaching the 20-30kt range late tonight/Wed.
The cold front will sweep across Lake Superior Wed aftn/evening.
While SW winds as high as 15-25kt should occur behind the front Wed
night into Thu morning, strongest between Isle Royale and the
Keweenaw Peninsula, the pressure gradient and winds will weaken for
a time Thu aftn and night as a low pressure trough develops over the
Upper Lakes ahead of a low pressure wave developing over the
southern Plains. After this low pressure wave passes late Thu
night/early Fri morning, NW winds up to 20-25kt will develop on Fri,
strongest over the e half of Lake Superior. NW winds up to 20kt will
linger into Sat.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...JLA
AVIATION...Voss
MARINE...Voss
Area Forecast Discussion
National Weather Service New York NY
637 PM EDT Tue Oct 4 2016
.SYNOPSIS...
High pressure builds down from Southeastern Canada through
Friday, then slides offshore by Saturday. A frontal system moves
across the area Saturday night into Sunday, followed by high
pressure returning early next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Made minor adjustments to the near term forecast to better reflect
the latest trends.
Deep layered ridging builds in from the west tonight. The
resulting subsidence should allow for improving sky
conditions. However, there is potential for low clouds to
redevelop late tonight. Latest thermodynamic profiles from the RAP
and HRRR do not show enough moisture in the low levels for
stratus. Will continue to show improving sky conditions overnight.
Lows tonight will range from the 40s inland to the lower 50s near
the coast.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Deep layered ridging continues to build in Wednesday and
Wednesday night with a westward extension of the sub-tropical
ridge building towards the region. Subsidence under the ridge
should promote minimal cloud cover, especially by Wednesday night.
For highs Wednesday, a blend of MET/ECS/MAV guidance, NAM 2-meter
temperatures and a mix down from 950 hPa was used, with values
forecast to be near to slightly above normal. Wednesday night, a
blend of MAV/MET/ECS guidance and NAM 2-meter temperatures was
used, weighed towards the lowest guidance at a point outside of
urban/immediate coastal areas to reflect decent radiational
cooling conditions. Lows should be a few degrees above normal
outside of normally cooler locations.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Much attention this period will focus on the future track and
evolution of Hurricane Matthew. Refer to the latest NHC advisories
for official track and intensity information.
High pressure across the Mid-Atlantic region will move offshore by
Saturday as Hurricane Matthew moves north along the eastern
seaboard. The latest model runs have a eastward shift in the
forecast track for Hurricane Matthew. This brings Matthew closer
to the Florida/Carolina coast Thursday night-Saturday, then east
of the 40N...70W benchmark on Sunday.
Meanwhile, a frontal system will move across the area Saturday into
Sunday. The combination of this frontal boundary and tropical
moisture advancing northward ahead of the tropical cyclone will
result in heavy rain across the area on Saturday night into Sunday.
At this time with the latest 12z track of this tropical cyclone,
rainfall values of 1 to 3 inches are possible, with the highest
amounts expected across our eastern zones.
Be vigilant and maintain good situational awareness for the
potential impacts from Matthew this weekend. Check back frequently
for the latest forecasts, specifically from the NHC for track and
intensity information, and your local forecast office for potential
impacts.
High pressure will then return Sunday night into Tuesday with
unseasonably cool conditions.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
High pressure builds into the area tonight, and remains over the
area through Wednesday.
Ceilings are likely to remain above 3500 feet into this evening.
Thereafter, cloud cover is only expected to be minimal.
As a result, VFR has been forecast through the TAF period.
There is a low probability that ceilings around 2000 feet develop
overnight into early Wednesday morning.
Northeasterly winds can be expected through tonight. The flow then
will attempt to veer to the east northeast after 15-18Z Wednesday.
...NY Metro Enhanced Aviation Weather Support...
Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90
KJFK TAF Comments: No unscheduled amendments are expected.
KLGA TAF Comments: No unscheduled amendments are expected.
KEWR TAF Comments: No unscheduled amendments are expected.
KTEB TAF Comments: No unscheduled amendments are expected.
KHPN TAF Comments: No unscheduled amendments are expected.
KISP TAF Comments: No unscheduled amendments are expected.
.Outlook for 18Z Wednesday through Sunday...
.Rest of Wednesday...VFR. Variable wind direction possible, with
speeds generally at or below 10 kt.
.Thursday-Friday...VFR.
.Saturday...VFR to start, then conditions may deteriorate to MVFR or
lower.
.Saturday night...Tropical impacts possible. Otherwise, a chance of
rain.
.Sunday...Tropical impacts possible. Otherwise, a chance of rain.
&&
.MARINE...
A moderate pressure gradient over the region will bring winds up
to 20 kt tonight, highest over the coastal ocean waters, where
gusts to 25 kt are also forecast. The pressure gradient relaxes
through Wednesday night, with winds up to 15 kt on the ocean and
at most 10 kt by Wednesday night over the non-ocean waters.
Seas on the coastal ocean waters will remain above 5 ft through
Wednesday night, so the SCA has been extended until 10z Thursday
as a result there.
Seas up to 5 ft could linger on the coastal ocean waters on
Thursday, otherwise sub-SCA conditions are expected on area
waters through Friday night.
Depending on the future track/strength of Hurricane Matthew, seas
of at least 5 ft could return by the weekend on the coastal ocean
waters.
&&
.HYDROLOGY...
It will be dry through Friday night.
Rainfall amounts for the weekend as a frontal boundary interacts
with moisture from a tropical cyclone could range between 1 to 3
inches. With the highest amounts expected over our eastern areas.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Thursday for ANZ350-353-
355.
&&
$$
SYNOPSIS...Maloit
NEAR TERM...Maloit/DS
SHORT TERM...Maloit
LONG TERM...Fig
AVIATION...MET
MARINE...Fig/Maloit
HYDROLOGY...Fig/Maloit
Area Forecast Discussion...CORRECTED
National Weather Service Norman OK
310 PM CDT TUE OCT 4 2016
.DISCUSSION...
Isolated severe thunderstorms may develop along the dryline late
this afternoon. Various convective-allowing models (HRRR/HRRRX/4KM
NAM) are persistent in discrete supercells developing across
southwest Oklahoma and moving northeastward into central Oklahoma.
Analysis of the HRRR indicates localized backing/increased
convergence along a dryline bulge could be a factor for convective
iniation in the models. Visible satellite imagery indicates a
possible perturbation/ascent across western north Texas/southwest
Oklahoma which might be aiding in pressure falls/localized
backing. There is some evidence of this perturbation on the 700
mb flow.
Vertical wind shear will be more than sufficient for supercells with
potential for large hail and damaging wind gusts. By around 00Z, low-
level (0-1 km) vertical wind shear (~20 knots), MLLCLs (<1 km),
and critical angles (~90 degrees) will result in sufficient
environment for potential tornadogenesis with any supercells.
Tomorrow, at least isolated showers/storms will be possible with a
moist, conditionally unstable airmass still in place.
Coverage/confidence for storms is low with no significant forcing.
Coverage may increase overnight as isentropic ascent increases.
By late Thursday into Thursday night, a seasonably strong cold front
will progress from northwest to southeast across Oklahoma/western
north Texas. Severe weather will be possible; however, because of
linear forcing along the cold front, the primary hazards will be
gusty winds and locally heavy rainfall. Lingering showers/storms
will be possible Friday morning across southern Oklahoma/western
north Texas.
Much drier/cooler air is expected in the front`s wake on Friday and
Saturday. Many locations will drop into the 40Fs by Saturday
morning, and with dew points dropping into the 30Fs and light
winds, some locations across northwest Oklahoma may drop into the
upper 30Fs.
By Sunday, a shortwave trough may increase the chance of showers,
especially northwest Oklahoma. The forecast becomes more uncertain
beyond Sunday as the GFS and ECMWF become somewhat out of phase
across the Southern Plains. However, a general pattern of quasi-
zonal flow with embedded shortwaves suggests seasonable
temperatures with at least a low chance of rain.
Mahale
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 66 88 69 87 / 50 10 30 30
Hobart OK 57 88 68 87 / 10 10 20 30
Wichita Falls TX 67 92 69 90 / 10 10 30 20
Gage OK 49 86 58 87 / 0 0 10 30
Ponca City OK 63 89 69 87 / 60 10 40 40
Durant OK 71 89 69 88 / 20 10 20 10
&&
.OUN Watches/Warnings/Advisories...
OK...None.
TX...None.
&&
$$
03/10