Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/30/17
Area Forecast Discussion
National Weather Service Albany NY
1021 PM EDT Fri Sep 29 2017
.SYNOPSIS...
A low pressure system and associated potent upper level
disturbance approaching from the Great Lakes, will bring some
showers to the region tonight into Saturday morning.
Temperatures will be even cooler on Saturday, with plenty of
clouds around through much of the day. High pressure will build
in Saturday night resulting in some frost. The high will
strengthen further Sunday into early next week. This will allow
temperatures to gradually moderate back to above normal levels
with continued dry conditions.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 1020 PM EDT...Potent upper wave well depicted in the H2O
vapor imagery this evening across Lake Ontario. Showers have
quickly redeveloped across eastern NY with impressive lift per
the RAP hourly analysis. This should continue to overspread the
region overnight as we will tweak the PoPs/Wx per radar and
radar-forecast trends. Otherwise, minimal changes to the
forecast at this time with excellent details below...
Prev Disc...The clouds/showers are associated with a vigorous
upper level trough approaching from the eastern Great Lakes.
Textbook swirl noted in GOES-16 visible satellite imagery over
the southern end of Georgian Bay associated with the main
vorticity max embedded in the trough. Lightning also noted with
some of the showers over western Lake Ontario.
Clouds and showers will move into our area from west to east
this evening and mostly after dark. A few showers may sneak into
the western Adirondacks and Mohawk Valley just before sunset.
Otherwise, the main batch of showers will move through the
majority of eastern NY and western New England later this
evening and into the overnight hours. Steepening mid-level lapse
rates (700-500mb LR 6.5-7.0 C/Km) and negative Showalter values
will result in isolated thunder embedded in the showers from
around I-90 southward. Wouldn`t be surprised if some brief
graupel or small hail in some spots.
The pivot point/track of the main vort max looks to be right
across the central part of the area near the Mohawk Valley and
Capital District, so areas to the south will experience less
persistent showers, with more coverage to the north. Will
mention highest pops from around Albany northward. Showers
should start to taper off from northwest to southeast on
Saturday, although plenty of clouds/showers will linger through
much of the morning/early afternoon due to the upper level
trough axis moving through. Will continue to mention isolated
thunder across southern areas. As a result, temperatures will be
quite cool with highs only in the 50s. Some breaks of sunshine
expected to occur late in the day, especially for areas north
and west of Albany.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
Surface high pressure will quickly build in behind the
departing trough Saturday night. This will result in clearing
skies and light winds. With already cool temperatures in place
and good radiational cooling conditions, lows expected to be in
the 30s. Frost is possible across many areas, especially across
higher terrain areas outside the Capital District. Freezing
conditions may occur across parts of the western Adirondacks.
Will continue to mention frost potential in the HWO.
Surface high pressure will then remain entrenched over the
region through Monday, with ridging aloft also occurring. This
will result in continued dry conditions Sunday and Monday.
Temperatures will also gradually moderate, as the air mass warms
in place. Temps should be near normal through Sunday night,
then warming to slightly above normal readings Monday afternoon.
In general, abundant sunshine is expected although there could
be some fog and/or low stratus clouds developing typical
locations in river valleys and other sheltered spots.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As per the previous excellent long term discussion, an
anomalously strong ridging (1-3 standard deviations above normal
at 500mb) will dominate through the mid week period. This will
bring above normal temperatures (H850 temperatures are 1-2
standard deviations above normal per the 12Z GEFS) and mainly
dry conditions through at least Wednesday.
Surface temperatures will average about 5-10 degrees above
normal to start the period, reaching 15 degrees above normal by
the mid week period. Dewpoints will be lower than earlier this
week with mainly 40s then climbing into the low-mid 50s,
although these values will be above normal by later in the week.
Despite warming temperatures, high temperature records look
safe at this time. With the highest readings expected by
Thursday to be near 80 at Albany, the record is 91 (The highest
record high on the books for October).
For the most part, dry conditions will prevail. Some
indications of a cold front approaching for Wednesday
night/Thursday that would impact the CWA. At this point, low
chance pops are all that is warranted as global models differ
significantly on timing (ECMWF remains the fastest timing when
compared to the GFS/GGEM).
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected to lower to MVFR by late this
evening as showers move in from the approach of impressive
compact wave approaches. Even after the showers move through,
MVFR conditions due to ceilings will persist through most of
remainder of the TAF period; 00Z/Sunday.
Light northwest to northeast flow at less than 10 mph will
become light/variable to calm overnight with a north to
northeast flow developing Saturday morning increasing to 7 to 10
knots.
Outlook...
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
&&
.FIRE WEATHER...
A low pressure system and associated potent upper level
disturbance approaching from the Great Lakes, will bring some
showers to the region tonight into Saturday morning.
Temperatures will be even cooler on Saturday, with plenty of
clouds around through much of the day. High pressure will build
in Saturday night resulting in some frost. The high will
strengthen further Sunday into early next week. This will allow
temperatures to gradually moderate back to above normal levels
with continued dry conditions.
Relative humidity values will increase to between 90 and 100
percent tonight, dropping to minimum values of around 50 to 65
percent Saturday afternoon. RH values will increase to around 90
to 100 percent Saturday night.
Winds tonight will be northeast around 5 mph, becoming north at
5 to 10 mph on Saturday. Winds will be northerly less than 5
mph Saturday night.
&&
.HYDROLOGY...
A prolonged dry stretch has been in place. Little to no
precipitation has fallen over eastern New York and western New
England over the last two weeks. The US Drought Monitor has
reintroduced some areas of D0 (Abnormally Dry) conditions in
parts of the area with this weeks Drought Monitor update.
A sharp upper level trough will move across the region tonight
into tomorrow. Some showers will accompany this system and most
areas look to pick up measurable precipitation. Amounts will be
fairly light, generally one to two tenths, with some spots in
the Adirondacks getting as much as a third of an inch. This
rainfall will have little to no impact on rivers and streams.
Behind this storm system, another stretch of dry weather looks
to be in place through much of the upcoming week. As a result,
rivers and streams will be holding steady through the next week.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...JPV
NEAR TERM...BGM/JPV
SHORT TERM...JPV
LONG TERM...BGM/OKeefe
AVIATION...IAA/BGM
FIRE WEATHER...JPV
HYDROLOGY...Frugis/JPV
Area Forecast Discussion
National Weather Service Denver/Boulder CO
956 PM MDT Fri Sep 29 2017
.UPDATE...
Issued at 922 PM MDT Fri Sep 29 2017
The showers are mostly over across the CWA at this time. Satellite
pictures are showing an upper level circulation over north
central Wyoming right now. There is still quite a bit of status
over the plains. Will make appropriate adjustments to those GFE
grids. Fog is again indicated on some of the models over night, so
will leave it in.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 347 PM MDT Fri Sep 29 2017
Stratus on the far eastern plains has held temperatures back
today, while sun closer to the foothills has warmed temperatures
into the mid 60s. Scattered showers are moving over the north-
central mountains with a few thunderstorms embedded. The threat of
showers will continue out onto the plains through the early
morning. Overnight, showers will end as the moist airmass
remains in place. Areas of stratus and fog are forecast by the
latest HRRR model runs, with the most likely areas to be up in
Weld County.
Tomorrow, models indicate the leading edge of an upper trough will
be moving over northwest Colorado in the afternoon. Showers are
likely to develop over the mountains which could be moving out
onto the plains in the late afternoon or early evening.
Temperatures are expected to be a few degrees warmer than today,
depending on how much stratus develops overnight.
.LONG TERM...(Saturday night through Friday)
Issued at 347 PM MDT Fri Sep 29 2017
Scattered showers and thunderstorms that develop tomorrow
afternoon will gradually decrease from west to east across the
plains Saturday evening as airmass stabilizes and weak subsidence
builds in behind departing wave. A few of the storms on the
eastern plains may be strong early in the evening with CAPES
pushing 1000-1500 J/kg. Hail and gusty winds the main threats.
Meanwhile, in the mountains, we should see an uptick in shower
coverage as orographic flow improves and cold advection kicks in,
and we`ll still have upper level divergence on the nose of the
powerful Pacific jet stream. We should see at least a couple
inches of snow on the higher mountain passes with some travel
impacts possible with slushy conditions in the heavier snow
showers. Snow levels are expected to lower to about 9000 feet by
Sunday morning, but snow is expected to decrease by then.
Attention then turns toward next and potentially stronger weather
maker. Models are becoming better aligned, but the details are
still hard to pin down. GFS is still the driest and warmest model
for our forecast area by a longshot, but we`ll lean toward the
colder and wetter ECMWF and Canadian for this package. There
should be a sharp gradient associated with the upper level jet,
with widespread banded precipitation near and north of the jet
axis, and drier conditions farther south. This may very well end
up straddling our forecast area, and areas generally along/north
of the I-70 corridor most favored for precipitation at this time.
The colder air arrives Sunday night, and then should remain
entrenched over most of the forecast area Monday. Models usually
struggle with the first southward push of cold air and
reinforcement associated with surface cyclone development and
increasing baroclinicity. That`s the reasoning for the much
colder forecast than GFS for Monday. Band of precipitation should
also shift farther southward than GFS indicates. Given the longer
duration event from Sunday night into Monday and Monday night,
along with potential for jet induced banding and lower snow
levels, significant amounts of snow will be possible over the
mountains. Again, this would favor mountains north of I-70 but
will continue to monitor southward progression over the next
couple days.
By Tuesday and Wednesday, we expect a piece of energy to shear off
and settle into the Desert Southwest. A drier southwesterly flow
may develop during this period with some moderation in temps. We
might actually return to normal temperatures by Thursday and
Friday as long as upper level trough shears out as expected
resulting in a continuation of drier west/southwest flow aloft.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 922 PM MDT Fri Sep 29 2017
Drainage has already kicked in at DIA, but speeds are pretty low.
on the 00Z tafs I left the fog in after 11Z. Visiblities will
likely not get below 2SM BR. Ceilings of BKN- OVC010-020 are
possible at DIA overnight into Saturday morning.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...RJK
SHORT TERM...Dankers
LONG TERM...Barjenbruch
AVIATION...RJK
Area Forecast Discussion
National Weather Service Taunton MA
1006 PM EDT Fri Sep 29 2017
.SYNOPSIS...
A fast moving low pressure system will bring a round of showers
and thunderstorms as well as unseasonably cool temperatures late
tonight into Saturday. Large high pressure will follow with dry
weather and cool nights and mild afternoons Sunday, Monday and
Tuesday. As the high drops south of our region, dry weather will
continue but with unseasonably warm afternoons Wednesday and Thursday.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
10 pm update...
Blanket of clouds on the increase from the W per latest satellite
imagery as well as light scattered shower activity. Chance PoPs
initially becoming more likely towards morning as the associated
low pressure center sweeping S/W of the region begins to emerge
over the warmer waters S of New England latching into low-level
warm-moist sub-tropical air well offshore and the column begins
to saturate (noting the 0z Albany sounding and surface dewpoint
depressions, how dry it is, how difficult it will be for initial
rains to reach the surface). Winds becoming more easterly as clouds
limit cooling. Looking at lows into the upper 40s to low 50s.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
*/ Highlights...
- Threat of thunderstorms and associated downpours possibly
over S-coastal New England, over the S waters especially
- Potential for seeing 0.50 up to an one-inch of rainfall in a
short period of time, more specifically, around RI and
S-coastal MA
- Risk of waterspouts over the S-waters associated with
thunderstorms
*/ Discussion...
As the surface low and associated positively-tilted trof axis and
cold pool aloft emerge S/W of the region over the warmer ocean
waters, anticipate the low to latch into low-level warm-moist
higher theta-E sub-tropical air well offshore. Beneath the cold
pool, lapse rates steepen (6-7 C/km) as LCLs remain low. Would
expect a greater isallobaric response per pressure / height falls
more so than the latest suite of high-res forecast guidance lead
on. This would subsequently increase the E component of low-level
winds beneath strong mid to upper level SW flow. An increasing
measure of 0-1 km shear and helicity in an environment of
potentially increasing instability on up to 1k J/kg. Storm
rotation can not be ruled out given low-level hodograph profiles.
Thus the concern that with any developing low-topped convection
that there is the risk of downpours, even the potential threat
of waterspouts given a more favorable environment of low-level
shear / helicity out over warmer sea-surface temperatures. This
in addition to the possibility of graupel / small hail given how
cold it is aloft, low wet-bulb freezing level heights, and the
likelihood of moisture being lofted pretty high up per expected
dynamics and strong omega forcing. Have enhanced thunderstorm
wording over the S-coast of RI and MA, especially around Block
Island, and collaborated with SPC, WPC, and OKX.
Some dissenting signal from NCAR ensembles and HRRR TLE, however
the latest trends from the HRRR / RAP / RPM show convection
blossoming around 15-18z Saturday in and around Block Island that
can`t be ignored. One interesting signal comes from the HRRR TLE
with increasing probability of 0.50 and 1.00 rainfall amounts in
an hour over RI into S-coastal MA, a signal suggesting vigorous
development with deepening column moisture likely associated
with the robust dynamics and anticipated cyclogenesis emerging
off the coastline signaled by the suite of latest forecast
guidance. The inverted-trof evolution with time, increasing the
low-level convergence and ushering widespread rainfall with
locally heavier amounts per thunderstorms discussed above.
As the previous forecaster noted, tough to pin down exactly
where heavier rain may occur given convective nature but best
chance may be near the south coast where best instability lies.
Activity clearing out towards late in the day. The cold airmass
aloft and abundance of clouds with a breezy E onshore flow, it
will surely feel like Autumn and not more like Summer as of late.
Highs only into the 50s with the widespread wet weather, perhaps
only into the upper 40s along the high terrain.
Saturday night...
Any leftover showers Saturday evening will be confined to the S
coast. Otherwise, expect clearing skies from N to S during the
night as trough exits and high pres builds in from the west. Chilly
night with lows upper 30s to mid 40s.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Highlights...
* Seasonable temperatures return Sunday into Tuesday
* Well above average temps for Wednesday into Thursday
* Dry weather will prevail for the period
Pattern Overview/Confidence...
12z guidance is in good agreement for the period leading to high
confidence in the forecast. Anomolous ridge will build across the
eastern CONUS beginning late Sunday into Monday as digging low moves
over the Northern Rockies. Surface high pressure will remain in
place during the work week as upper level ridge continues to build.
In fact ensembles indicate this ridge will be near 2-3 STD above
normal. Upper level high will begin to shift south and west over the
southern Plains by the late week. This may allow for a weak front to
swing through late in the week.
Details...
Temperatures...
Surface high pressure building over the region Sunday into Tuesday
will lead to more seasonable temperatures with highs in the upper
60s to low 70s. Despite 850 mb temps warming aloft onshore flow each
day will limit heating. Clear skies each night will allow for temps
to drop into the the low 40s across the interior. Upper level ridge
will crest over the region by Wednesday/Thursday as 850 mb temps
will be 2 STD above normal. Surface winds will switch to a more W/SW
direction increasing mixing and thus warming temps well above
average. Anticipate upper 70s to low 80s across the area with a few
spots near the mid-80s. Approaching frontal system by Friday will
drop temps a few degrees but still above average for early October.
Precipitation...
Stout high pressure will keep the region dry for much of the
extended. Could see a bit of fog by Wed/Thursday as low level
moisture begins to increase but confidence in that developing is
low. Next shot for precip could be around the Friday time-frame.
However, 700 mb moisture is quiet low and model QPF is fairly light
thus will keep only a slight chc for now.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Saturday Night/...High confidence.
Tonight into Saturday...
Conditions lowering to MVFR late tonight and especially Saturday
from west to east as SHRA overspread the region. Pockets of
IFR. Greater threat of TSRA along the S-coast and over BID,
perhaps MVY, around 15-18z Saturday. +RA possible along with
small hail. E winds on the increase throughout, gusts up to 20
kts forecast.
Saturday night...
Patchy MVFR cigs near the south coast in the evening, otherwise
VFR with clearing skies from N to S. Patchy late night fog
may develop in the CT valley.
KBOS TAF...Sea breeze/onshore flow continues overnight. MVFR
conditions move in Sat morning with showers. High confidence.
KBDL TAF...High confidence.
Outlook /Sunday through Wednesday/...
Sunday through Wednesday...High confidence in mainly VFR
conditions.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Saturday Night/...High confidence.
Light winds tonight, then increasing E/NE winds developing
Saturday with gusts to 20-25 kt possible, especially S coastal
waters. Will drop the SCA as seas have subsided below 5 ft, but
may need one Saturday on the south coastal waters for marginal
wind gusts up around 20 kts and seas near 5 ft.
Also worth noting is the threat for thunderstorms and locally
heavy downpours over the S waters towards late morning into
midday. With thunderstorms, can not rule out the threat of
waterspouts. So a heads up for mariners Saturday morning into
afternoon.
Will see winds turn N and diminish into Saturday night. Any
elevated seas dampening.
Outlook /Sunday through Wednesday/...
Sunday through Wednesday...High confidence. Large high pressure in
control should generally keep winds/seas below small craft advisory
thresholds. We may see some easterly swell bring marginal 5 foot
seas into some of our outer-waters Monday night or Tuesday.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...KJC/Dunten
NEAR TERM...KJC/Dunten/Sipprell
SHORT TERM...KJC
LONG TERM...Dunten
AVIATION...KJC/Dunten/Sipprell
MARINE...KJC/Dunten/Sipprell
Area Forecast Discussion
National Weather Service Wilmington NC
956 PM EDT Fri Sep 29 2017
.SYNOPSIS...
A cold frontal passage early Saturday will be followed with
cooler temperatures and dry air under increasing northeast
winds through the weekend and well into next week. Any chance
for showers will occur tonight prior to the cool surge. Any
leftover clouds will scour out by midday Saturday. Modest
Canadian high pressure will ridge down the east coast this
weekend and persist well into next week. This will result in
mostly sunny days and clear nights with temperatures running at
or slightly below normal.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 930 PM Friday...Latest near term models, ie. HRRR,
indicate spotty pcpn possible ahead of the cool surge mainly
during the pre-dawn Sat hours before finally exiting east and
south of the coastal areas by daytime mid-morning. Have tweaked
POPs to 15 to 25 percent with the 25 POPs along the immediate
coast and adjacent Atl waters. The atm column moisture depth by
Sat morning will be even lower than what transpires this
evening. Thus kept the pcpn type showers with no thunder. Some
tweaking of the hourly sfc temps/dewpoints based on latest obs
trends and HRRR model runs with the min temp fcst mainly
unchanged. Latest models want to clear out the FA quicker then
what`s fcst, will make some tweaks in that general direction but
refrain from going full tilt.
Previous.........................................................
AS OF 300 PM Friday...A surface cold front lies between
Charleston and Georgetown, SC and extends offshore into the
Atlantic south of Cape Fear and Cape Lookout. North of this
boundary a shallow layer of northeasterly winds has brought in
significantly cooler air than we had yesterday, although
dewpoints have not yet dropped more than a few degrees. Over the
next few hours we could still see an area of showers and maybe
a t-storm develop across eastern South Carolina just inland from
the coast. This is the only spot in our forecast area where
surface-based instability is not capped by warm temperatures
above the frontal inversion. Should any convection develop,
storm motion is likely to be slow as surface winds are about 180
degrees out of phase with 10,000 foot winds.
A mid and upper level trough over the Great Lakes will sweep
east into New England tonight. This should induce surface low
pressure to develop near Long Island, NY. This low and 1032 mb
Canadian high pressure approaching the Great Lakes late tonight
should give our cold front a shove to the south. Accelerating
northeasterly winds late tonight into Saturday should finally
scour out the last of the moisture pooled near the front, with a
truly fall-like Canadian airmass spreading into the Carolinas
Saturday. A few late night showers are possible over SE North
Carolina and coastal South Carolina late tonight into Saturday
morning as this surge of northeasterly winds arrive, with
clearing skies and breezy northeasterly winds expected for the
rest of the day.
Models are tightly clustered with temperatures through Saturday
and I see no reason to deviate significantly. We`re expecting
lows tonight in the mid 60s inland and upper 60s at the coast,
and daytime highs Saturday in the upper 70s over SE North
Carolina and lower 80s over NE South Carolina.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 300 PM Friday...Cooler Fall-like weather through the
period as Canadian high pressure builds down from the north,
with breezy northeast winds and plenty of bright early Oct sun
on Sunday. Temps will actually start out below normal with
readings in the lower end of 50s for lows Sat night in plenty of
cool advection, except along the coast where relatively warmer
ocean temps will keep it several degrees warmer overnight. After
a cool start on Sunday, temps will only reach the lower 70s
most places inland as heights begin a slow rebound as upper
ridge shifts east.
Soundings show a bit of moisture later on Sun just under 5k ft
stuck under subsidence inversion and therefore may see some
strato cu clouds late in the afternoon into the eve but very dry
below and above. Overall a very dry and cool period with pcp
water values below a half inch and dewpoint temps bottoming out
down near 50 Sunday morning.
Toward the end of the period heading into Mon morning, there
will be a decent easterly low level push which should produce
enough moisture convergence to moisten the column between 1 and
5k ft mainly just along the coast. Should see clouds and chc of
mainly sprinkles along the coast as column remains very dry
through the mid levels with plenty of subsidence. Pcp water
values reach back up near 1 inch.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 300 PM Friday...Expect seasonal temperatures through the
long term and generally dry conditions as high pressure sinks
south from New England to the mid- Atlantic states. Exception to
the dry conditions will be along the coast where modest
convergence could bring isolated showers/sprinkles and some
increased cloud cover. A frontal system may approach/affect the
eastern Carolinas near the end of the long term, but due to
model divergence timing of this event is uncertain.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
As of 00Z...VFR/MVFR this evening, becoming MVFR with possible
IFR from the pre-dawn Sat hrs thru daylight mid-morning.
Persistent and isolated trw/rw over Marion County will continue
a slow death with the absence of insolation, as it drifts
eastward. CRE and MYR may see debris stratocu or altocu for a
few hrs this evening. Otherwise, all terminals will eventually
see stratocu or stratus in the 1500 to 2500 ft level. The
coastal terminals may see the stratus sink to around 1k ft after
08Z along with showers in the vicinity. This brief pcpn and
associated clouds will produce MVFR/IFR conditions associated
and ahead of a secondary cool surge that will push the sfc cold
front well south of the forecast area during daylight Saturday.
By midday Sat, all terminals should be in VFR mode. Winds
generally from the ENE 10 kt or less this evening backing to
NNE-NE 5 to 10 kt during the pre-dawn Sat hrs. By midday Sat,
the secondary cool surge will have commenced, with winds all
terminals generally NE 10 to 15 kt, with G20 kt especially
across the coastal terminals.
Extended Outlook...Mainly VFR conditions...except for possible
MVFR ceilings Sunday as stronger onshore winds develop.
&&
.MARINE...
NEAR TERM /THROUGH SATURDAY/...
As of 930 PM Friday...Some tweaks to wind speeds this evening
thru the overnight based on latest obs trends. Tweaked a
slightly hier windspeed to the cool NE surge during Sat and Sat
night due to the cooler and drier air advecting over the warm
Atl SSTs. Models indicate 25 to 30 kt NE winds to materialize
just off the deck by Sat aftn and continuing into Sun. This
should easily mix down to the sfc as wind gusts at times.
Previous.....................................................
As of 300 PM Friday...A surface cold front has slid as far south as
Bulls Bay in northern Charleston county. To the north of this
boundary northeasterly winds have developed, although they`ve been
pretty light south of Myrtle Beach so far. The strongest winds have
remained north of Cape Fear where 15-20 knots all morning cranked
seas up to 4-5 feet, recently confirmed by the CORMP nearshore
Wrightsville Beach buoy.
The next major change in our weather conditions should occur
Saturday morning as low pressure developing off the New England
coastline and reasonably strong Canadian high pressure over the
Great Lakes increase our northeasterly winds substantially. Winds
should increase to around 20 knots with 25 knot gusts possible. Seas
should build to 4-6 feet over open waters, and we still have a Small
Craft Advisory posted beginning at noon Saturday.
SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 300 PM Friday...Small craft conditions will persist
through the period in gusty northeast winds up to 30 kts.
Generally, expect seas 4 to 6 ft with some 7 fters in the outer
waters in shorter period wind waves and choppy conditions.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
As of 300 PM Friday...Strong high pressure dropping south from
New England will keep up a steady NEly flow of around 15 to 20
kts through the period, with seas ranging from 4 to 6 ft most
places and closer to 3 ft in sheltered locations. It is likely
that a Small Craft Advisory will need to be extended into the
middle of the week due to this.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...Beach Hazards Statement from 7 AM EDT Saturday through
Saturday evening for SCZ054-056.
NC...Beach Hazards Statement from 7 AM EDT Saturday through
Saturday evening for NCZ106-108.
MARINE...Small Craft Advisory from noon Saturday to 6 AM EDT Monday for
AMZ250-252-254-256.
&&
$$
SYNOPSIS...TRA
NEAR TERM...DCH/TRA
SHORT TERM...RGZ
LONG TERM...REK
AVIATION...DCH
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1017 PM EDT Fri Sep 29 2017
.SYNOPSIS...
A cold front will move south through the area overnight. High
pressure will build in from the north this weekend and will be
the main feature through most of next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 1010 PM Friday...Light to moderate showers with area of
stratocumulus clouds continue over the northeastern CWA this
evening. Have continue with chance PoPs over the northern CWA
per latest HRRR model. As reinforcing cold front crosses the
region toward morning, there will be a small chance of showers
over the southern zones toward morning. Made no major changes to
the overnight forecast with low temperatures tonight in the
upper 50s inland to mid 60s coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
As of 315 pm Fri...Dry air will overtake the entire forecast
area by late morning. Have carried only a slight chance along
south coast and southern Outer Banks through mid-morning, then
dry. Highs in the mid 70s northeast to upper 70s southwest.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 345 PM Friday...
Surface high pressure over the Great Lakes early in the period
will slowly move southeast over the northern Atlantic by mid
week and remain in control of our weather. This will mean mainly
dry weather through the period, especially inland. Starting
Monday maintained a slight chance to low chance for showers
mainly over the coastal water, but at times over the Outer Banks
and immediate coastline for a few spotty showers. With an upper
level high just to our west and extremely dry air above 10,000
feet, on first glance it would be hard to imagine anything but a
dry forecast next week. However with the position of the high
over the northern Atlantic, we will have a persistent onshore
flow. Model soundings for KHAT show moisture between 3,000 and
7,000 feet, with a much drier looking sounding inland. This
matches up well with a slight chance to low chance rain forecast
for the bulk of next week along the coast itself.
Temps will start out below normal Sunday and Monday or in the
70s for highs. By mid week and beyond temps recover to near
normal (around 80) if not a tad above by weeks end.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Short Term /through 00Z Sun/
As of 715 pm Fri...Will forecast prevailing VFR conditions
overnight although ceilings at the southern TAF sites of KEWN
and KOAJ may flirt with MVFR over the next few hours. A few
stray showers may also accompany a reinforcing frontal system
that will move south overnight. Drier air should arrive between
09z and 12z. Winds should be sufficient to preclude much in the
way of fog formation.
Long Term /Saturday night through Wednesday/
As of 345 PM Friday...VFR should dominate with high pressure
controlling our weather through the period.
&&
.MARINE...
Short Term /through Sat/
As of 1015 PM Friday...Winds continue generally E/NE at 5-15
knots across the region with seas 3-5 feet. No big changes made
to the current forecast. A weak cold front will move south
through the marine zones overnight, moving off the south coast
around 12Z. Winds will pick up a bit Saturday, with 10-15 knots
north of Ocracoke and 15-20 knots south. Seas Saturday 3-5 ft
throughout.
Long Term /Saturday night through Wednesday/
As of 345 PM Friday...Prolonged period of poor boating most
waters with moderate NE flow as strong high pres builds in from
the N. NE winds 15 to 25 kts expected Saturday night thru Sunday
with seas building to 5 to 7 feet. Issued a small craft advisory
for all coastal waters and the Pamlico Sound starting late
Saturday/early Saturday evening based on current forecast.
Although this is getting into the third period, confidence is
high and this will allow us to match up with surrounding offices
of ILM and AKQ.
E to ENE winds continue Mon and Tue at 10 to 20 kts. The long
fetch of onshore winds will keep seas elevated in the 5 to 6
foot range most outer waters early next week. Wave watch
guidance indicating 7 foot seas through mid week. Based on wind
speeds capped waves at 6 feet, which look to be especially high
off our central waters near Cape Hatteras.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 7 PM Saturday to 11 AM EDT Sunday
for AMZ135.
Small Craft Advisory from 6 PM Saturday to 8 PM EDT Wednesday
for AMZ152-154.
Small Craft Advisory from 6 PM Saturday to 11 PM EDT Sunday
for AMZ156-158.
Small Craft Advisory from 7 PM Saturday to 8 AM EDT Monday for
AMZ150.
&&
$$
SYNOPSIS...HSA
NEAR TERM...CTC
SHORT TERM...HSA
LONG TERM...EH
AVIATION...CTC/EH/HSA
MARINE...CTC/EH/HSA