Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/16/17
Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Sun Oct 15 2017
.UPDATE...
Issued at 1042 PM EDT Sun Oct 15 2017
Conditions really quieting down this evening, with winds becoming
rather light and minimal shower activity. Upstream largely
moisture starved wave will arrive during the early morning,
perhaps kicking off a few more lake induced showers. Not a big
deal for sure. Temperatures will continue their slow descent,
bottoming out well into the 30s across interior areas, with just a
bit warmer readings near the big waters.
&&
.NEAR TERM...(Tonight through Monday)
Issued at 329 PM EDT Sun Oct 15 2017
...Cool but quieting down...
High impact weather potential...winds diminishing quickly this
evening.
993mb surface low is quickly scooting eastward across southern
Quebec. The associated cold front has exited MI. Final area of
wraparound synoptic precip is pushing across central/eastern
portions of northern MI, and will exit over the next few hours. Some
lake enhanced showers are noted upstream on MQT radar. In general,
our wx is quieting down during the near term period, with wind and
precip trends the primary concern.
Winds have not lived up to their billing today. Gusts to around
35mph are relatively common, but we are struggling to get much more
than that. Expect winds to remain relatively steady state thru 6 pm
or so, with a very rapid falloff as we hit dusk and beyond. Per
coord with GRR/DTX, will cancel the wind advisory a bit early.
As mentioned above, widespread rain will exit to the east before
sunset. We are plenty unstable enough for lake effect, with 850mb
temps -2 to -4c. But inversion heights are dropping below 5k ft this
evening, with plenty of dry air above that. This should make it
difficult to get more than spotty showers. Rap runs have generally
been pretty dry for the 1st half of the night, and then spit out
some QPF south of TVC after 2 am. Will have some slight chance to
sct pops in western Chip Co, nw lower MI, and between Rogers City
and APN. Is there a chance to get something besides rain? Perhaps,
though the modified marine layer will make that a challenge. Still,
a few snowflakes could sneak in overnight, especially in western
Chip Co.
Will stretch slight chance pops into Monday morning in parts of nw
Chip Co and nw lower MI. Otherwise, 1000-850mb winds will be backing
and 850mb warm advection will develop. That will eliminate any lake-
induced precip. Diurnal heating in the chilly and marine-moistened
airmass will contribute to substantial cu/stratocu by afternoon.
Min temps tonight mainly in the 30s, around 40f along the nw lower
MI coast. Max temps Monday primarily in the mid 50s.
&&
.SHORT TERM...(Monday night through Wednesday)
Issued at 329 PM EDT Sun Oct 15 2017
...Moderating temperatures...
High Impact Weather Potential: None.
Pattern Forecast: By Monday night, a mid level wave and attendant
surface reflection are expected to be crossing the northern Ontario/
Hudson Bay region with high pressure anchored over the Ohio Valley.
Northern Michigan will lie in somewhat of a transition zone with
ongoing warm air advection expected to continue right through the
middle of the week.
Primary Forecast Concerns/Challenges: Little in the way of sensible
weather; however, occasionally gusty winds (not nearly as strong
as Sunday) are possible at various times through midweek.
As aforementioned low pressure over Ontario passes by to our north,
occasionally gusty winds are expected Monday night...especially over
the waters of the Great Lakes. Gustiness continues early Tuesday as
ongoing warm air advection aids to boost temperatures several
degrees warmer than Monday. High temps anticipated to top out in the
low-mid 60s area-wide Tuesday, although it`ll feel cooler than that
with wind gusts approaching 20 mph midday into the afternoon.
A similar story is expected Wednesday with another, more potent,
wave passing through southern Canada. High pressure anchored to the
south should yield another precip-free day under partly to mostly
sunny skies locally, but again may feature a bit of midday and
afternoon gustiness as a tighter gradient sags in from the north.
High temps another few degrees warmer...ranging from the low-mid 60s
north and from 65-70 degrees south of the bridge.
.LONG TERM...(Wednesday night through Sunday)
Issued at 329 PM EDT Sun Oct 15 2017
High pressure over the eastern CONUS will bring a rather quiet
extended period. Warming temperatures will once again be the main
story heading into the weekend. Highs over the weekend are expected
to be 10 to 20 degrees above normal. A cold front approaching the
area early next week will bring the next chance for rain.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1144 PM EDT Sun Oct 15 2017
Lake effect clouds and a few light showers expected to continue
tonight, although conditions are expected to remain mostly VFR.
More shallow VFR producing cumulus/strato-cu expected to develop
again later this morning and afternoon. Winds become light
tonight, increasing in speed some out of the west later today.
&&
.MARINE...
Issued at 329 PM EDT Sun Oct 15 2017
Low pressure is rapidly heading east across Quebec. Pressure
gradient will relax rapidly, especially after sunset. Gale force
gusts are still seen occasionally, but those should transition to
small craft advisories this evening. West to sw winds will ramp up
again late Monday and especially Monday night, and additional
advisories will be needed by then.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 5 AM EDT Monday for LHZ347>349.
LM...SMALL CRAFT ADVISORY until 5 AM EDT Monday for LMZ323-342-
344>346.
LS...SMALL CRAFT ADVISORY until 5 AM EDT Monday for LSZ321.
&&
$$
UPDATE...MB
NEAR TERM...JZ
SHORT TERM...MG
LONG TERM...AM
AVIATION...MB
MARINE...JZ
Area Forecast Discussion
National Weather Service Taunton MA
1032 PM EDT Sun Oct 15 2017
.SYNOPSIS...
A strong cold front sweeps across the region overnight and will
bring scattered showers into early Monday morning. Behind the
front, it turns sharply cooler and brisk Monday afternoon with
temperatures dropping down close to freezing by daybreak
Tuesday. Gradual warm up through the week, possibly into the
weekend, while overall dry and quiet with scattered cloud decks
and breezy winds from time to time.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1015 PM Update...
Line of showers continues progress SE out of NY state, reaching
the northern Berkshires at 02Z. Noting gusty SW winds along the
southern near shore waters. Gusts up to 32 kt at KEWB, 34 kt at
KFMH and 32 kt at KPVC, with a peak wind of 35 kt at KPYM and 31
kt at KCQX. Also noting gusts to around 30 kt across portions of
E Mass into RI, so very good low level mixing continues this
evening.
Noting the showers ahead and along the approaching cold front
have been tending to slowly weaken, but bands of stronger
reflectivity still seen. Short range and high res models do
continue the trend of weakening this line further as it crosses
the region overnight.
Near term forecast pretty much on track so far with temps
mainly in the mid-upper 60s across the region, which will remain
steady through around 06Z or so, then will fall pretty quickly
as the cold front pushes across through the remainder of the
night.
Previous Discussion...
As the fine-line progresses E there less instability to work
with. However riding the cold front along and ahead of which the
activity is maintaining is stout. A very fine thermal
discontinuity met with a decent pressure couplet as discerned
from the latest SPC / high- res mesoanalysis. A lot of
frontogenetical convergence along the line that with heavier
precipitation outcomes coupled with both the isallobaric and
gradient winds is lending to mechanical mix-down of very fast
westerly winds, in excess of 40 mph observed over the E Great
Lakes Region. Some question as to the inversion over our region
and a limited threat, however RAP sounding profiles highlight
that along the front the inversion is somewhat eroded.
In all, the expectation is for the fine-line to weaken, but
closely keeping an eye give the associated synoptics. Expect the
cold front to sweep across after midnight, and could see winds
amplify with a brief period of 35 to 45 mph gusts, more likely
behind the cold front out of the W/NW.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Monday...
A few left over showers will be possible across the far SE New
England coast during the first part of Monday morning. Otherwise,
expect some strato-cumulus to work into the region in the cool
advection pattern but will also see some peeks of sunshine.
Temperatures late Monday morning and afternoon will mainly be in
the upper 50s to the lower 60s, but a bit cooler in the higher
terrain. Northwest wind gusts of 20 to 30 mph will make it feel
chilly compared to our recent mild weather.
Monday night...
High pressure will build in from the west allowing winds to
gradually diminish, except across the southeast New England
coast. Cool airmass in place should allow overnight low temps to
drop to around 30 to the lower 30s in the normally coolest
outlying locations. Some frost/freeze headlines will likely be
needed where the growing season is technically still in place.
Lastly, it will be milder across the Cape/Nantucket as NNW winds
will result in ocean effect cloudiness and holding low temps in
the 40s. 850T to seas surface temperature differential around
20C may even yield an isolated shower or two.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
*/ Highlights...
- Gradual warm-up through the week into the weekend
- Perhaps a pattern change into late October, more active, cooler
*/ Overview and Discussion...
Change is on the horizon. A deeper polar low upstream shifting from
the Siberian Peninsula E into Alaska diminishes downshearing
storm development over the W CONUS and rather promotes ridging
into late October. Concurrent with a strong MJO phase 4/5/6
signal, and the expectation is for mild, moist Pacific air to
pump into the W CONUS ahead of deep troughing over the NE
Pacific. Meanwhile this also promotes downshear deeper troughing
over the E CONUS.
But prior to, as the polar low matures E into Alaska, individual
upstream Pacific origin waves continue to slam into the
Cascades later emerging downstream and undergoing cyclogenesis
NE into Canada. High pressure is promoted over the SE CONUS
beneath preferred H5 ridging. Subsequent SW pump of warmer air
across the Central into E CONUS as far N/E into NE Canada.
Looking at a suppressed environment over S New England.
Aside from a series of weak frontal passages concurrent with
breezy winds, Tuesday night into Wednesday, and again Thursday
night into Friday with light shower activity over N New England
high terrain, otherwise little to no wet-weather activity given
abundant dry air through the following weekend. Main story is
the warming temperature trend for late October beginning near-
seasonable with highs around the low to mid 60s warming into the
70s, possibly into the 80s by the weekend.
Consensus of model guidance preferred which signals the low to
mid level high situated over the SE CONUS out to Bermuda round
which the heat pump flows, breaking down early next week as
Pacific energy shears off into the SW CONUS as high pressure
builds around the coast of CA. The pattern flips and troughing
becomes promoted into the NE CONUS. Looking at the next cold
frontal passage and chance of wet weather potentially beginning
around Monday night into Tuesday.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Monday Night/...High confidence.
Overnight...
MVFR-IFR CIGS linger over SE terminals, with SCT-BKN clouds
around 2-3Kft elsewhere. Mainly VFR VSBYS across the region. SW
wind gusts up to 30 to briefly 35 kt along the S coast, Cape Cod
and the islands and 20-30 kt elsewhere. Expect winds to quickly
shift to W-NW with the frontal passage. Could see brief gusts
up to around 35 kt or so with the front.
A line of SCT SHRA will push across the terminals ahead of the
cold front which should push offshore by around 09Z or so.
Monday...
SCT SHRA ending. SW winds turning W/NW. CIGs improving, BKN to
SCT low-end VFR. Low risk MVFR early. Gusts around 20 to 25 kts.
Monday night...
VFR other than perhaps a period of some marginal MVFR ocean effect
clouds across the Cape/ACK. Winds diminish for most but NW wind
gusts of 20 to 25 knots continue for Cape/Islands.
KBOS Terminal...Strongest winds developing and likely to continue
towards midnight. Already gusts in excess of 30 kts. Will push
higher around 35 kts for tonight.
KBDL Terminal...SW wind gusts increasing. Expect strongest winds
at the beginning of the TAF period going into midnight. Monitoring
the fine-line W which will move into the terminal close to 10p
behind which winds revert NW continuing into the early morning
hours Monday, remaining gusty but around 20 kts.
Outlook /Tuesday through Friday/...Moderate confidence.
Tuesday through Friday...
VFR. W winds. Breezy at times, around late Tuesday and again late
Thursday
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Monday Night/...High confidence.
Overnight...
SW winds gusting up to 25-30 kt will continue overnight, with
brief gale force gusts across the southern near shore waters
especially Buzzards Bay, Vineyard Sound and Nantucket Sound as
well as the eastern open waters through around midnight. Small
crafts continued for all waters. Scattered showers move across
the waters after 06Z or so with the cold front. Winds quickly
shift to W-NW with the frontal passage mainly across the eastern
waters around 07Z-09Z
Monday and Monday night...
Behind the sweeping cold front, NW gusts 20 to 30 kts, close to
near gale force, especially over the open waters. Strongest
winds immediately behind the front and then into Monday night
given colder air aloft building S over the warm waters. SMALL
CRAFT ADVISORIES continue and may need to be extended.
Outlook /Tuesday through Friday/...Moderate confidence.
Overall W winds, breezy at times around late Tuesday and again late
Thursday. Waves for the most part below 5 feet, only issues worth
noting are on the S/SE outer waters early Tuesday, possibly again
Thursday night into Friday. Otherwise good boating weather.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until noon EDT Monday for ANZ231>235-237-
251.
Small Craft Advisory until 8 AM EDT Monday for ANZ230-236.
Small Craft Advisory until 8 AM EDT Tuesday for ANZ250-254>256.
&&
$$
SYNOPSIS...Frank/Sipprell
NEAR TERM...Sipprell/EVT
SHORT TERM...Frank
LONG TERM...Sipprell
AVIATION...Frank/Sipprell/EVT
MARINE...Frank/Sipprell/EVT
Area Forecast Discussion
National Weather Service Charleston SC
942 PM EDT Sun Oct 15 2017
.SYNOPSIS...
High pressure will weaken tonight into Monday. A strong cold
front will move through the region Monday evening. High
pressure will then build into the region and will prevail
through next weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The forecast is on track and only required minor adjustments.
The latest NARRE-TL (Time-lagged North America Rapid Refresh
Ensemble System) has increased the probabilities for dense fog
to 80-90% from Walterboro to near Beaufort east across much of
the Charleston Tri-County area 09-12z Monday. Have introduced
some dense fog wording into the grids and text forecasts in this
area given this trend.
The primary forecast concern for the overnight period once again
centers on the potential for fog development. Forecast soundings
show a nearly identical airmass to 24 hours ago, but the flow
atop the boundary layer is forecast to be weaker than what was
experienced this morning. Should see a combination of fog and
low stratus develop during early Monday morning with conditions
favoring areas roughly along and east of the I-95 corridor for
the better chances for dense fog. In fact, vsby output most of
the high resolution models for the past several runs now show
an increasing potential for widespread fog with vsbys 1/4 mile
or less in the 3-9 am time period, so confidence is increasing
that a Dense Fog Advisory may be needed for some areas later
tonight. RAP wind fields do show 1000 hPa winds increasing to
about 10-15 kt in the Reidsville-Allendale corridor after 09z
in response to the approach of a cold front and a thickening
mid- level cloud deck, so this may limit the fog coverage there
and support a bit more in the way of low stratus. For this
update, will continue to highlight "areas of fog" for all but
the Reidsville-Allendale corridor where "patchy fog" will be
placed. Lows from the mid 60s interior Southeast Georgia to the
lower 70s at the coast look on track.
Expect mainly dry conditions to prevail through daybreak Monday.
Isolated showers are likely to develop over the coastal waters
in the vicinity of a weak land breeze circulation that moves
offshore later tonight. A band of showers will also likely be
approaching the far western zones by 6 am. Latest guidance
suggests this will likely remain out of the far western zones
prior to sunrise.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Monday: An amplifying, positively tilted upper shortwave trough will
advance toward the region Monday and will cross the region Monday
night/Tuesday. This trough will drive the strongest cold front thus
far this season through the region late Monday into Monday evening.
While isolated showers/thunderstorms could precede the front, the
axis of deepest moisture/best precipitation will reside along/north
of the boundary. Also, a weak wave could develop along the front,
and the 850 mb front will lag behind the surface boundary. This
anafront scenario suggests that best precipitation coverage
featuring numerous/widespread showers and isolated thunderstorms
will push through the region Monday afternoon/evening, a few hours
slower than previous forecasts. The latest forecast indicates likely
POPs with timing adjusted to indicate later timing. Higher POPs and
additional timing adjustments to perhaps delayer higher POPs early
then extend higher POPs deeper into Monday evening could eventually
be needed.
Monday night through Wednesday: The axis of deep-layered moisture
will push south/east and will eventually push out of most/all areas
Monday night. Showers will linger longest across southern coastal
counties. Meanwhile, high pressure will then push much cooler air
into the region, supporting lows in the 50s most areas and 60s along
the GA coast due to onshore winds. Tuesday, temps will only top out
in the lower/mid 70s most areas, followed by mid/upper 70s
Wednesday. Tuesday night, temperatures will range from the upper 40s
well inland to the lower 60s on the GA coast where onshore flow will
continue. Also of note, long fetch northeast flow produced by high
pressure will push Atlantic moisture onshore especially across
southern counties, supporting isolated/scattered showers especially
along the GA coast.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A large surface high will yield dry weather and gradually warming
temperatures through the end of the week. A few showers are possible
over the coastal waters, possibly brushing immediate coastal
areas at times.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Primary concerns:
* Fog/low-stratus with IFR or lower conditions
* Timing of showers/tstms with a strong cold front
Biggest near term concern is for IFR or lower conditions
associate with fog and low-stratus early Monday. Confidence is
increasing that impacts will occur at both terminals. Fog
conditions look the most favorable at KCHS where dense fog could
occur for a few hours prior to daybreak and lingering to the
mid-morning hours. Seeing a fairly uniform dense fog pattern in
the various high resolution guidance which increases confidence.
Will continue to trend conditions down at both KCHS and KSAV.
For KCHS, will show vsbys and cigs right at airfield minimums
at KCHS (1/2SM FG and OVC002) in a TEMPO group from roughly
10-13z, but lower conditions, including prevailing 1/4SM FG
VV001 can not be ruled out. For KSAV, slightly less mid-level
over the boundary layer could prevent conditions from cratering
there. Will limit vsbys to 2SM (right at alternate minimum
thresholds and not establish a cig, but show SCT002. It is
still very possible that lower conditions will occur.
A strong cold front will cross the terminal late afternoon
Monday bringing a few hours of showers/tstms. Will show
prevailing MVFR vsbys in moderate rains for now from 20-24z at
KCHS and 21-24z at KSAV. Will not include a mention of TSRA
just yet as there remains some instability uncertainties.
Extended Aviation Outlook: Brief flight restrictions possible Monday
afternoon into Monday evening especially within showers/isolated
tstms. VFR later Monday night through Thursday.
&&
.MARINE...
There are increasing concerns that fog, possibly dense, could
impact the Charleston Harbor and nearby Atlantic waters out 10
nm Monday morning. Added "areas of fog" to these zones to
account for this possibility. A Marine Dense Fog Advisory may be
needed.
The coastal trough well offshore is forecast to weaken overnight
while the strong cold front upstream is expected to reaches
upstate SC and north GA late. Weak onshore winds late this
afternoon will become light and variable overnight. There will
still be some lingering 2-3 ft swells and these should make up
most of the wave component overnight. Seas 4-5 ft close to the
Gulf stream over our far outer GA waters should subside to 3-4
ft with time.
Focus centers on significant cold air advection and associated
hazardous wind/sea event expected to commence late Monday/Monday
evening and continuing to some degree into Thursday.
A strong cold front will cross the waters from north/northwest to
south/southeast late Monday into Monday evening. In the wake of cold
fropa, strong north/northeast winds will surge into the waters, and
seas will build quickly. Then, strong high pressure will build from
the north, and a tight surface pressure gradient and a mixed marine
layer tapping into elevated winds aloft will maintain elevated
winds/seas through the middle of this week. Winds will gradually
diminish around the middle of the week, but elevated seas will
persist into Thursday across near shore waters and beyond across the
outer GA waters.
Due in part to the prevalence of at least 35 knot winds within the
950-925 mb layer and the likelihood for a deeper marine mixed layer
near the west wall of the Gulf Stream, raised a Gale Watch for
AMZ374 valid Monday evening into Tuesday afternoon. Then, SCA
conditions should persist across the outer GA waters into at least
late week.
Across near shore waters, confidence is high in a solid Small Craft
Advisory event starting late Monday/Monday evening and continuing
into Thursday to account for persist 6 ft seas. However, due to some
uncertainty regarding timing and magnitude of stronger winds for
Charleston Harbor, opted not to issue an SCA here to allow later
shifts to assess updated guidance.
&&
.TIDES/COASTAL FLOODING...
Strong/persistent northeast winds will push higher water levels to
the coast this week. Minor coastal flooding will be possible around
the times of high tide beginning Tuesday morning and continuing
into Thursday. Coastal Flood Advisories could eventually be
needed.
&&
.EQUIPMENT...
Hourly observations and daily climate data from the weather
sensor along Riley Waterfront Park (KCXM) in Downtown
Charleston will not be available until further notice. The cause
of the senor outage is unknown at this time. Technicians will
assess the equipment on Monday.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory from 6 PM Monday to 5 PM EDT Thursday for
AMZ352.
Gale Watch from Monday evening through Tuesday afternoon for
AMZ374.
Small Craft Advisory from 5 PM Monday to 5 PM EDT Thursday for
AMZ350.
Small Craft Advisory from 7 PM Monday to 5 PM EDT Thursday for
AMZ354.
&&
$$
Area Forecast Discussion
National Weather Service State College PA
1159 PM EDT Sun Oct 15 2017
.SYNOPSIS...
A strong cold front will push through the region tonight.
Blustery and cool weather is in store for Monday. Temperatures
will rebound to near normal on Tuesday, then continue to
gradually rise to well above normal right into this upcoming
weekend, as a large area of high pressure builds east over Ohio
Valley and Mid Atlantic states bringing an extended period of
dry conditions.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
The cold front extends from just east of Wellsville NY down to
between Indiana and Johnstown. A narrow cold frontal rain band
is just out ahead of the and is causing briefly gusty winds and
rainshowers.
The HRRR shows the line continuing quickly SE while diminishing
in intensity as cooler air begins to downslope into the forecast
area.
QPF should be on the low side, a tenth of an inch or less in
most areas where the rain moves through this evening.
After the front clears the area this evening, the cold NW flow
will make quite a dramatic difference in the temps, and
especially the apparent temps considering a brisk breeze from
the WNW overnight.
After being so warm, the drop to much below normal temps and
cold cross-lake flow...strato cu and sprinkles/light showers
will be a shock.
Min temps early Monday will vary from the U30s to L40s across
the NW mtns and Laurel Highlands, to the lower 50s in the SE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
For Monday, we expect to see maxes about 5-10F below normal
with highs ranging from the U40s to L50s across the mtns, to
around 60F in the SE.
As the mid-level thermal trough crosses the region Monday,
isolated to scattered instability (and lake effect) showers
will occur across the NW Mtns and Laurel Highlands, with just
some sprinkles accompanying expanding MDT cu clouds in the
afternoon elsewhere.
The NW wind gusting between 20-25 mph will trim another 8-10
degrees off what the air temp should feel like on our skin.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
As the upper level trough deepens as it moves eastward, cold
air, with readings of around 6C at 850 mb will move over the
region by Tuesday morning. Temperatures will be slightly below
normal with readings in the mid 30s. Frost across much of
Central and Northern PA remains likely with even sub- freezing
conditions across the perennial cold spots INVOF KBFD.
For the mid to late week period, heights gradually rise with a
multi-model consensus indicating a string of dry and
increasingly warm days and mainly clear/cool nights. We could
have a period true Indian Summer weather with high temps in the
in the low to mid 70s from mid week into next weekend.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
A strong cold front has pushed southeast of the entire region as
of late this evening. In the wake of the front, low level
moisture ascending the western mountains should produce
predominantly MVFR cigs at KBFD and KJST the rest of the night
into Monday morning. Elsewhere, the drying effect of a
downsloping northwest flow should result in predominantly VFR
conditions through tonight.
High pressure will build into the region Monday, bringing
clearing skies and gusty northwest winds. Model soundings
indicate lingering MVFR cigs at KBFD/KJST will give way VFR
conditions by around 16Z.
Outlook...
Tue-Wed...Patchy AM fog possible.
Thu...No sig wx expected.
Fri...Patchy AM fog possible.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...La Corte/Lambert
NEAR TERM...La Corte/Lambert
SHORT TERM...Lambert
LONG TERM...Ceru
AVIATION...Fitzgerald
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
341 PM PDT Sun Oct 15 2017
.UPDATE...Updated air quality issues.
&&
.SYNOPSIS...Above normal temperatures through Wednesday with a
significant cooling trend Thursday into the weekend. Showers will
be possible across much of the area Thursday through Friday.
&&
.DISCUSSION...Upper level high pressure over the desert southwest
began to build northwest into southern and central California
resulting in a warming trend. Temperatures this afternoon were
generally between 6 and 9 degrees warmer compared to 24 hours ago
and are forecast to warm to around 5 degrees above normal for the
middle of October. Continued warming is expected on Monday...which
also looks to be the warmest day of the week...with daytime high
temepratures climbing to nearly 10 degrees above normal. Above
normal temperatures will prevail across the area into Wednesday.
Breezy offshore winds were present this afternoon across the Kern
County mountains as well as near the Grapevine...where wind gusts
between 20 and 25 mph were observed. The strongest winds were
right near the Grapevine today...where gusts to 44 mph were
observed this morning and this afternoon. The HRRR has been
consistently advertising that winds will subside in the next few
hours.
Otherwise...the focus of the forecast shifts from warm and dry to
cool and possibly wet Thursday into Friday as an upper trough
begins to impact the Pacific Northwest and northern California
coastline on Thursday. The best chance for precipitation across
the area will be from Fresno county northward Thursday evening
into Friday. Snow levels with the bulk of precipitation will
generally hover between 9000 and 10000 feet.
Yesterday afternoon the forecast models indicated that the entire
region would see precipitation...where today those same models
are keeping the bulk of the precipitation from Fresno county
northward. We will continue to closely watch model trends over the
next 24 and 48 hours and hopefully nail down timing as well as
amounts of precipitation expected. Either way...we are confident
that the entire region will see a significant cooldown...as much
as 20 degrees between Monday and Friday.
Another thing to note...NCEPs Global Ensemble has decreased
predictability in the upper level pattern for Thursday and Friday
compared to 24 hours ago...adding to our uncertainty in the
extended forecast. Please continue to monitor the forecast for the
latest information.
&&
.AVIATION...
Areas of MVFR visibilities due to smoke can be expected in the San
Joaquin Valley, foothills and higher elevations of the Sierra Nevada
for at least the next 24 hours, with VFR conditions prevailing
elsewhere across the Central California Interior.
&&
.AIR QUALITY ISSUES...
Please see SFOAQAHNX for an Air Quality Alert.
On Monday October 16 2017... Unhealthy for sensitive groups in
Kern County.
Further information is available at Valleyair.org
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
Red Flag Warning until 6 PM PDT this evening CAZ295.
Wind Advisory until 5 PM PDT this afternoon CAZ095.
Wind Advisory until 5 PM PDT this afternoon CAZ091-092.
&&
$$
public...Riley
avn/fw...BSO
synopsis...Riley
weather.gov/hanford
Area Forecast Discussion
National Weather Service Jackson MS
910 PM CDT Sun Oct 15 2017
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Scattered showers and isolated storms continue this evening as a
cold front moves through the region. Precip should end later
tonight, with lows ranging from the mid 40s north to around 60
southeast. As for the current forecast, increased evening pops for
most locations and added thunder in the south for this evening. No
other changes were needed. /27/
Prior discussion below:
Tonight and Monday: Latest RAP and satellite imagery showed a
strong upper trough moving through the mid section of the CONUS.
This was dragging a cold front toward the region from the
northwest. Area radars were picking up warm advection showers and
isolated thunderstorms. Readings across the region were in the
lower to middle 80s.
For tonight, the front will swing through the region for late
this afternoon through tonight. The rains will decrease from the
northwest in the wake of the front. The showers will end across
our southeast counties prior to dawn. A more seasonably cool
airmass will infiltrate the region with lows in the upper 40s
north to the lower 60s southeast.
For Monday, sunny skies and cool below normal readings will be
the general rule with highs from the upper 60s to the lower 70s.
The surface high pressure will build across the region from the
northwest as the upper trough swings across the region./17/
Monday night through Saturday: Light cold air advection will
continue Monday night as the pressure gradient remains tight between
surface high pressure ridge over the TN valley and the cold front
along the coast. Still, expect mins to fall into the 40s given the
dryness of the airmass.
A slow warming trend will get underway Tuesday as mid level heights
begin rising from the west. Shortwave ridge looks to develop over
the Southern Plains by midweek and will result in surface temps
climbing back into the lower 80s by Thursday. Surface ridge will
remain anchored over the southeast states with east/northeast winds
keeping the air dry. The increasing warmth by mid to late week with
the airmass remaining dry may begin to promote some afternoon fire
risks. However, winds look to remain weak. Will continue to monitor
this potential in future forecasts.
By Saturday, the surface ridge will have pushed far enough south to
begin pushing low level moisture back into the area from the Gulf of
Mexico. The mid level ridge will also have pushed east of the area
allowing PWs to increase to around 1.75 over western portions by
Saturday afternoon. These conditions should promote at least slight
chance pops over the southwest quarter./26/
&&
.AVIATION...
00Z TAF discussion:
Adjustments were made to ceilings/weather for this evening based
on frontal timing trends, but expect VFR conditions to return
quickly along with gusty northerly winds through Monday following
the front, which is expected to move through the entire area by
late tonight. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 52 72 46 74 / 30 0 1 1
Meridian 55 72 47 74 / 47 2 1 1
Vicksburg 51 72 45 75 / 52 0 1 1
Hattiesburg 61 72 48 75 / 40 9 1 1
Natchez 52 71 46 74 / 31 1 1 1
Greenville 48 71 44 74 / 25 0 1 1
Greenwood 48 71 44 74 / 47 0 1 1
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1019 PM EDT Sun Oct 15 2017
.UPDATE...
Issued at 1019 PM EDT SUN OCT 15 2017
Cold front has cleared eastern Kentucky. However, the H850 trough
is only about 125 miles behind the surface front, following close
behind and now moving to the southeast across our area. This
feature is kicking off a second band of showers which is
currently moving across our southwestern zones. HRRR has picked
up on this new development and brings it east-northeast across
the southeastern half of our forecast area over the next several
hours, though weakening with time. Consequently had to adjust
PoPs to account for this activity. Also made adjustments to the
temps and dew points as the cooler, drier air appears to be moving
in more rapidly than originally forecast, again the result of the
H850 trough which is typically a useful feature for timing the
more credible cooler and drier air into some given region.
UPDATE Issued at 759 PM EDT SUN OCT 15 2017
Strong, fast moving cold front is a little more than half way
through the forecast area. Expectations are that it will exit
eastern Kentucky between 9 and 10 p.m. this evening. Winds along
and just behind the front have been gusting as high as 40-45 mph
through the late afternoon and early evening. But there seems to
have been a decreasing trend over the last hour or so. There has
also been some isolated thunder through the evening as well. But
the threat of thunder should end in the next hour or so. Frontal
boundary will continue to push east overnight as northwesterly
winds gradually drop off. Clouds will also linger until closer to
dawn. Adjusted PoPs, sfc temps and dew points for the early
evening update, mainly in an attempt to better capture changes in
sensible elements associated with the frontal zone as it pushes
across the area.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 317 PM EDT SUN OCT 15 2017
A broken line of showers well ahead of the approaching cold front is
moving across the area. The lack of instability has limited the
strength of the convection, but instability is a little greater in
the southwest part of the area where 18Z SPC mesoanalysis has
CAPE over 1000 j/kg. Some lightning has shown up southwest of the
forecast area in far northern TN near the KY border so will
continue to carry a slight chance of thunder for the next few
hours. Other scattered showers are near the front which has passed
SDF and CVG. There are some gusty winds with the front with a
peak wind of 36 knots at CVG and 39 knots at SDF.
The front will move quickly southeast across the area late this
afternoon and early evening and be southeast of KY by around 00Z.
The shower chance will diminish quickly after the frontal passage
and much cooler air will spread into the area. While fog will
likely limit frost formation Monday night, there may still be some
scattered frost in some areas.
.LONG TERM...(Tuesday through Sunday)
Issued at 317 PM EDT SUN OCT 15 2017
There is good model agreement with the evolution of the overall
upper level flow across the United States during the coming week.
Initially there will be weak troughing in the east, and weak ridging
over the southwest U.S. This will transition to a slightly wavy
zonal flow, but by the end of the week as troughing develops in the
west, upper ridging will build in the east. Overall this means an
extended period of dry weather for us, with warming temperatures.
At the beginning of the period we will still be under the influence
of the cool air mass which will overspread the area Sunday night,
and frost remains a possibility in a few spots Wednesday morning.
However on Tuesday the surface high will begin a gradual shift to
the east and this will combine with a building upper level ridge
late in the week to bring a warming trend, with temperatures well
above normal by the end of the week. Very warm weather will continue
through next weekend with readings around 10 degrees above normal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 759 PM EDT SUN OCT 15 2017
Strong, fast moving cold front is a little more than half way
through the forecast area. Expectations are that it will exit
eastern Kentucky between 9 and 10 p.m. this evening. Winds along
and just behind the front have been gusting as high as 40-45 mph
through the late afternoon and early evening. But there seems to
have been a decreasing trend over the last hour or so. There has
also been some isolated thunder through the evening as well. But
the threat of thunder should end in the next hour or so. Frontal
boundary will continue to push east overnight as northwesterly
winds gradually drop off to around 5 kts and shower activity comes
to an end. Generally MVFR CIGS will linger until around dawn.
Northwest winds will increase again as diurnal effects kick in,
generally about 10 kts.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...SBH
LONG TERM...SBH
AVIATION...RAY
Area Forecast Discussion
National Weather Service Mount Holly NJ
927 PM EDT Sun Oct 15 2017
.SYNOPSIS...
A cold front will progress to the east and move through our region
later tonight. High pressure is then expected to settle over the
eastern part of the country for the period from Monday through
Sunday. There may be a weak cold frontal passage Thursday night.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
930 pm update: Cold front continues to blast eastward across the
Northeast this evening. Objective 01Z surface analysis shows the
front positioned from a 991-mb surface low near the Quebec/New
Brunswick border to near Burlington, VT, to near Altoona, PA
with very strong 3-hour pressure rises continuing upstream of
the front/low. Front should reach the western CWA within 2 to 3
hours. Thin line of low- topped convection is slowly diminishing
along the front, but there has been increasing lift and
precipitation echoes (albeit quite light) upstream of the band
recently. As synoptic- scale lift increases via upper-jet
dynamics and differential cyclonic vorticity advection
downstream of a potent vort max in the Great Lakes region, more
light rain/showers should develop just behind the front. Latest
HRRR and NAM Nest are quite consistent with this signal,
especially southeast of the I-78 corridor, late tonight. Current
PoP/Wx grids look OK for now, though they still might be timed
a little on the fast side.
Main changes to the grids were more edits to winds/sky cover
given latest trends (finally some clearing in the area) and to
increase dew points in the pre-frontal regime.
Portions of previous discussion included below...
Subjective 22Z surface analysis indicates a 992-mb surface low
in far southeastern Quebec with a trailing cold front near
Watertown, NY, to just west of Pittsburgh with substantial (7-9
mb) 3-hour surface MSLP rises on the upstream side of the
front/low. Frontal lift is aiding in the generation of low-
topped convection along the front, and with very strong winds
aloft, some damaging wind gusts have occurred with the line this
afternoon in western NY and northwest PA. This convection will
wane rapidly this evening as what little instability is present
will nocturnally diminish. However, synoptic-scale lift will get
a boost from a strong vort max rapidly progressing eastward
through the Ohio Valley and Great Lakes region tonight. Aided by
upper-level divergence via the right entrance region of a
250-mb jet streak atop the Mid-Atlantic, post-frontal light
precipitation should develop across the area late this evening
through early tomorrow morning. The rapid progression of the
system and unimpressive vertical profiles of moisture suggest
accumulations should be light (generally near or below a tenth
of an inch).
Winds should turn northwest as the front moves through the area
after midnight and may become gusty, especially in the vicinity
of showers. The increased winds and continued mixing upstream
of the front should hinder a rapid drop in temperatures after
frontal passage. Instead, this should just prevent much of a
diurnal rise in temperatures tomorrow.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
High pressure will begin to build over the area Monday. Clearing
will continue to progress NW to SE over the area. Winds will remain
gusty through the day as decent cold air advection continues.
Temperatures will mostly remain level or continue a slow fall thru
the day. Early highs in the low 60s north and low/mid 60s
south/east.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Hazards...A frost advisory was issued for a small portion of ne PA
and nw NJ early Tuesday and coverage may need to be expanded in
future forecasts. Additionally... the GFS is flagging potential
widespread freeze frost for eastern NJ early Wednesday.
Fire weather: please see that section for a brief note on elevated
fire danger potential midday and Monday afternoon.
500MB: A short wave crosses New England Monday evening. Another
trough passes by, further north across Quebec Tuesday and yet
another on Thursday, then very strong ridging (several standard
deviations above normal) develops across the Great Lakes and
northeast USA late in the week through at least next weekend.
Temperatures...
October has averaged 8 to 9 degrees above normal for the first 14
days of the month, excluding the ACY Marina where departures from
normal are less due to the tempering influence of the nearby ocean
(both warm and cold). Calendar day averages Tuesday should be a
a couple of degrees below normal, warming Wednesday to nearly 5
degrees above normal, and eventually to daily averages 10 degrees
above normal Saturday and Sunday. The daily diurnals will be larger
than usual due to the dry airmass in place and light wind fields,
nighttime lows probably a little colder than statistically modeled.
Forecast basis...This forecast was a 50 50 blend of the 12z/15
GFS/NAM MOS Monday night-Tuesday night, the 12z/15 GFS MEXMOS
Wednesday and thereafter the D4-8 WPC 15z/15 12 hourly max/min T
and POP, and the 6 hourly td, wind and sky. The very warm GFS
D4-8 was not used.
The dailies...
Monday night...Gusty northwest winds to 20 mph early, otherwise
chilling with late night decoupling aiding radiational cooling and
the likelihood of scattered to widespread frost near dawn Tuesday,
north of I-78, especially near and north of I-80. A frost advisory
was issued where temperatures appears to give us the best chance
for frost or freezing occurrence. (Isolated frost and freezing
temps have already occurred in this advisory area).
The gusty north wind may continue all of Monday night along the
coasts and there is uncertainty whether there will be enough
decoupling s of I-78 to have issued any advisories there at
this time.
Tuesday-Sunday...Surface high pressure is forecast to build
eastward, with its center settling over the Virginias on Tuesday
before sliding off the Middle Atlantic coast on Wednesday. The
center of the high is anticipated to move back to West Virginia
and vicinity for Thursday through Sunday. Our region will remain
under the influence of the high through the period. As a
result, we are expecting dry weather conditions. This flux of
the high pressure centroid may also be associated with a slight
temporary cooling Friday with the preceding possible weak cfp
Thu night.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Low-confidence forecast tonight. CIGs are beginning to scatter
out at PHL/ILG/MIV/ACY, but fluctuations between SCT/BKN from
2000-3000 feet may continue this evening at all sites. CIGs
should fill back in, though likely somewhat higher (3000-5000
feet) overnight as a cold front approaches. Scattered showers
are likely 03Z to 12Z, with brief sub-VFR VSBYs and somewhat
lower CIGs possible. Winds will veer to northwest in the 05Z to
10Z time window with potential for gusty/erratic winds near
showers. Skies should rapidly improve after 12Z, but northwest
winds will increase to 10 to 15 kts with gusts 20 to 25 kts
possible by late morning through the afternoon.
Given the low confidence in the CIGs, impacts of showers, and
timing of cold front/wind shift...expect several amendments to
the TAFs through the overnight hours.
OUTLOOK...
Monday night through Friday...VFR with mostly a light westerly
wind...possibly gusty 15-20 kt Thursday and Friday.
&&
.MARINE...
6:30 pm update: Winds have approached/exceeded advisory criteria
at buoy 44009, and are slowly increasing elsewhere. In addition,
seas are creeping toward 5 feet across the coastal waters.
Current advisory looks good and made no changes to it. Did,
however, slow the changeover to northwest winds slightly and
slowed the increase in winds this evening to account for the
latest observational trends.
Previous discussion below...
We will keep the SCA flag in place since winds will be increasing as
the front nears, and gusty winds will continue after fropa.
Scattered showers moving across the waters with the front after
midnight and probably mostly done shortly after dawn. Winds mostly
SW ahead of the front and turning NW behind it. Fair weather
expected Monday.
OUTLOOK...
Monday night...A Small Craft Advisory is in effect for a northwest
wind gusting around 25 to 30 knots.
Tuesday..There may be a leftover northerly wind SCA lingering
into the early daylight hours on Tuesday.
Tuesday night through Friday...No marine headlines are anticipated
with generally a westerly flow and gusts under 22 kt.
&&
.FIRE WEATHER...
A northwest wind 10 to 20 MPH with gusts around 25 MPH is
expected for Monday. Relative humidity values are forecast to
drop into the 30s in much of our region on Monday afternoon.
Rainfall amounts associated with tonight`s cold frontal passage
should be light. As a result, there is a heightened fire weather
concern for Monday.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Frost Advisory from 2 AM to 8 AM EDT Tuesday for PAZ054-055.
NJ...Frost Advisory from 2 AM to 8 AM EDT Tuesday for NJZ001-007-
008.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ430-431-
450>455.
&&
$$
Synopsis...Drag
Near Term...CMS
Short Term...O`Hara
Long Term...Drag
Aviation...CMS/Drag
Marine...CMS/Drag
Fire Weather...Iovino/O`Hara