Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/08/17
Area Forecast Discussion
National Weather Service Taunton MA
938 PM EST Tue Nov 7 2017
.SYNOPSIS...
Low pressure passing south of the region will bring a period of
light rain mainly south of the Mass Pike this evening into the
overnight. High pressure will result in dry conditions and
seasonably cool temperatures Wednesday into Thursday. An
approaching arctic front may trigger a few rain/snow showers
Thursday evening and then usher much colder air into the region
for Friday and Saturday. There is a chance of precipitation for
Sunday night into Monday, but confidence is low at this time.
High pressure then builds into the area for mid week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
935 PM update...
While sfc low tracks well to the south, deep moisture plume
ahead of sharpening mid level trough and right entrance region
of upper jet moving through northern New England providing
enough moisture and synoptic lift for area of rain moving across
SNE this evening, especially near the coast. Along the northern
edge of the precip shield across interior MA, getting reports
of some snow mixing in. RAP low level temps below 850 mb
indicate potential for some mix with snow southward into
higher terrain of northern CT and NW RI through midnight. Temps
above freezing so no accum expected, except perhaps a coating on
the grass over higher elevations.
As system is progressive and moving eastward, precip already
ending in NW MA and will end south of the Pike after midnight
from W to SE with Cape/Islands the last to dry out late tonight.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
For Wednesday, the low will continue its eastward movement away
from the coast, with the pressure gradient gradually decreasing
across the area as high pressure builds in. A much cooler, drier
air mass will be advected southward in weakening northerly flow,
with highs in the the 40s to near 50. Cool temperatures will
continue into Wednesday night with freezing temperatures across
all areas, with the exception of perhaps the immediate coast.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Highlights...
* Much colder and coldest temperatures so far this season
expected Friday into the weekend with a winter feel
* Chance for precipitation late Sunday into Monday but low confidence
Cool temperatures continue into Thursday though with some
moderation in return flow along the coast as high pressure moves
offshore. A cold front will approach by evening, and although
there will be little moisture, a brief return of low-level
moisture may be supportive of a brief passing shower or light
drizzle overnight.
Following the frontal passage, strong cold advection follows
with gusty winds and the coldest air mass of the season so far
settling across the area. Highs will only reach into the 30s for
most areas, with 40s closer to the coast. Cold temperatures will
continue into Friday night, with a hard freeze expected even at
the coast as temperatures plummet into the teens to the upper
20s.
Dry conditions will continue into Saturday and much of Sunday as
high pressure builds across the area, though with temperatures
subtly increasing each day as the air mass begins to moderate.
Thereafter confidence decreases as the southern stream jet begins
to shift northward. Precipitation chances late Sunday into
Monday depend largely on the phasing of two embedded short wave
troughs. The developing system will need to be monitored. By
Monday or Monday night, the system will begin to move eastward,
with high pressure and drier conditions by mid week.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Wednesday Night/...
Overnight...Moderate confidence. A mix of VFR/MVFR conditions
in light rain mixed with snow over higher elevations in interior
MA and northern CT. Precip ending south of the Pike from W to
SE 04-09z. NE gusts to 20-25 kt developing Cape/Islands after
midnight.
Wednesday...Moderate confidence. Areas of MVFR cigs across
eastern New Eng improving to VFR, but lower cigs may lingering
across Cape/Islands into the afternoon. NE gusts to 20-25 kt
Cape/Islands diminishing in the afternoon.
Wednesday Night...High confidence. VFR.
KBOS Terminal...High confidence. Onset of light rain and
development of a marginal CIG this evening should be within an
hour either side of TAF. Wet Runway.
KBDL Terminal...Moderate confidence. BKN025-035 may move in
1-3 hours earlier than forecast. Timing of the arrival of light
rain could be earlier than forecast by an hour or so.
Outlook /Thursday through Sunday/... High confidence.
Thursday: VFR.
Thursday Night: VFR. Breezy. Slight chance SHRA.
Friday: VFR. Windy with local gusts to 30 kt.
Friday Night through Veterans Day:VFR. Breezy.
Saturday Night: VFR.
Sunday: VFR. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Wednesday Night/...High confidence.
N/NE winds increasing tonight into Wed morning as low pres
intensifies to the south. Gusts to 25-30 kt developing over the
south coastal waters with some higher gusts reaching into the NE
MA waters. Winds diminishing Wed afternoon. Small craft
advisories extended into Wed for increasing winds and seas.
Vsbys lowering tonight in rain and patchy fog, improving Wed.
Outlook /Thursday through Sunday/...Moderate Confidence.
Thursday: Winds less than 25 kt. Areas of seas approaching
5 ft.
Thursday Night: Low risk for Small Craft Advisory winds with
local gusts up to 30 kt. Local rough seas. Chance of rain
showers.
Friday: Strong winds with local gusts up to 30 kt. Rough seas
up to 10 ft.
Friday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas.
Veterans Day: Winds less than 25 kt. Seas locally approaching
5 ft.
Saturday Night: Winds less than 25 kt.
Sunday: Winds less than 25 kt. Slight chance of rain showers.
&&
.CLIMATE...
High temperatures Friday Nov 10 may approach record cold max
temps.
Here are the current record coldest max temps:
Boston 37 (1873)
Providence 34 (1956)
Hartford 37 (1914)
Worcester 32 (1956)
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 PM EST Wednesday for ANZ232>235-
237.
Small Craft Advisory from 4 AM to 4 PM EST Wednesday for
ANZ231.
Small Craft Advisory until 6 AM EST Thursday for ANZ250-
254>256.
Small Craft Advisory from 1 AM Wednesday to 6 AM EST Thursday
for ANZ251.
&&
$$
SYNOPSIS...WFO New York
NEAR TERM...KJC
SHORT TERM...WFO New York
LONG TERM...WFO New York
AVIATION...Belk/WFO New York
MARINE...Belk/WFO New York
CLIMATE...
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
921 PM CST Tue Nov 7 2017
.DISCUSSION...KCRP radar indicates the cold front has moved into
the northern portion of the forecast area, from Victoria to Choke
Canyon Lake to Dilley. Front continues to move south at around 15
mph. Latest MSAS analysis shows the strongest pressure rises from
the Hill Country to the I-10 corridor between San Antonio and
Houston. Derived image from GOES 16 shows higher moisture over the
coastal plains in advance of the front with PWAT values around 1.5
inches. But radars are showing only very weak showers forming in
the post-frontal area. Latest HRRR and Texas Tech WRF along with
GFS expected a bit more coverage of light showers with the front
by this time. Will lower PoPs to slight chance for the overnight
hours. With front pushing south a little quicker, made adjustments
to temperatures. With cloud cover and cold air advection, the
northern part of the forecast area should not make it out of the
50s. A refreshing change for Wednesday after spell of well above
normal temperatures in the 90s. No changes made to PoPs for
Wednesday but lift may not reach the area until the afternoon with
the approaching short wave trough.
&&
.PREVIOUS DISCUSSION... /Issued 552 PM CST Tue Nov 7 2017/
DISCUSSION...See Aviation section for 00Z TAFs.
AVIATION...Cold front just south of the I-10 corridor continues
to move south at around 15 mph. Expect frontal passage at VCT
around 03Z. Low MVFR ceilings from 1000-1500 feet will be
prevalent behind the front. Scattered light showers will be
possible for a few hours behind the front as well. The front is
expected to reach the CRP-ALI area around 09Z and LRD by 11Z.
Ceilings will persist around 1500 feet after the front Wednesday
with gusty north winds. Isolated showers will be possible Wednesday
morning with coverage increasing from the west during the
afternoon as an upper level disturbance moves into the Hill
Country.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 61 63 54 64 53 / 20 30 60 30 20
Victoria 56 58 51 65 49 / 20 20 60 20 10
Laredo 61 64 52 60 53 / 20 30 40 20 10
Alice 60 62 51 63 51 / 20 30 60 20 20
Rockport 61 63 54 67 54 / 20 30 60 20 10
Cotulla 57 59 51 64 50 / 20 40 40 10 10
Kingsville 63 64 53 63 53 / 20 30 60 30 20
Navy Corpus 65 67 56 65 58 / 20 30 60 30 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
TMT/89...SHORT TERM
Area Forecast Discussion
National Weather Service Green Bay WI
541 PM CST Tue Nov 7 2017
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Wednesday
Issued at 148 PM CST Tue Nov 7 2017
The latest RAP analysis and satellite/radar imagery show high
pressure centered from the northern Rockies to the Great Lakes
early this afternoon. Mid and high clouds have moved out of
Wisconsin and into northern Illinois, while backing winds have
caused lake effect clouds to retreat north out of north-central
WI. The next cold front is digging southeast across central
Canada, with mid and high clouds already approaching the northern
MN border. Because impacts from this next system are not expected
to arrive until Wednesday night, concerns mainly revolve around
cloud cover and temps in this part of the forecast.
Tonight...High pressure will slide to the southeast into the
Central Plains at the same time as the next cold front approaches
northern Minnesota by early Wednesday morning. Will see cirrus
increase from northwest to southeast starting around late in the
evening. Because the pressure gradient will remain relatively
tight, chances for the wind to decouple look low. So think temps
will not have an opportunity to tank despite the very dry arctic
airmass in place. Have therefore remained conservative with temps,
with lows ranging from the mid teens in the north to the mid 20s
in the southern Fox Valley.
Wednesday...The cold front will move into northwest Wisconsin by
late in the afternoon. Deeper cloud cover will reside behind the
front, so the threat of precip should hold off until evening. Will
otherwise see periods of scattered to broken cirrus overhead for
much of the day. High temperatures will range from the low 30s in
Vilas County to the lower 40s near the Lake.
.LONG TERM...Wednesday Night Through Tuesday
Issued at 148 PM CST Tue Nov 7 2017
An active weather pattern is in store for Wednesday night into
Thursday as the upper level trough moves through, accompanied by
very strong cold air advection. A shortwave will help lend some
instability to the region, making Snowfall likely for much of
northeastern Wisconsin in the early morning hours on Thursday.
The primary focus during this time period and into Friday however,
will be far northern Wisconsin where the mesoscale influence of
Lake Superior will make snow fall totals higher, especially for
Vilas County. Higher snow totals will be possible in far northern
Wisconsin if the winds currently forecast to be northwesterly take
a more northerly turn.
Strong cold air advection continues through Thursday, as 850mb
temperatures are pushed to the -15C and colder range. Expect
relatively minimal warming during the day on Thursday as cold air
continues to flow across the region, keeping high temperatures
well below normal. High pressure will rotate off towards the east
by late Friday night, bringing a chance to see temperatures rise
once more towards the beginning of the weekend.
Southerly flow into the weekend will herald the next approaching
trough for the region, as the next chance to see some active
weather arrives. Snow is expected to return to the region on
Saturday with the upper level trough, along with a fairly
saturated column thanks to the southerly flow through the earlier
parts of the day. Warming near the Fox Valley and lakeshore
through this period may be sufficient for a switch to rain in the
afternoon, before any lingering precipitation once again returns
to snow towards the end of the day. Quieter conditions return by
Sunday into Monday.
Well below normal temperatures start on Thursday and linger on
into Friday before southerly flow gets temperatures closer to
normal by the end of the weekend.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 500 PM CST Tue Nov 7 2017
VFR conditions will continue through Wednesday afternoon.
Gusty winds also expected on Wednesday after 16z, with gusts
to around 20 knots possible from the west. Winds will subside
by 23z. Snow removal/salting operations will be needed Wednesday
night into Thursday morning across northern Wisconsin. Snow
arrives across the northern Wisconsin Wednesday evening and
overspreads the remainder of the area early on Thursday morning.
Highest snowfall totals expected across the far north with a
dusting south of highway 10.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Uhlmann
AVIATION.......Eckberg
Area Forecast Discussion
National Weather Service Wilmington NC
931 PM EST Tue Nov 7 2017
.SYNOPSIS...
A slow moving cold front nearly overhead tonight, will drop south
of the area before stalling during Wednesday. Weak surface lows will
move along the stalled front bringing unsettled conditions through
late Thursday. Strong Canadian high pressure will finally bring cool
and dry conditions as it wedges strongly down the coast Friday thru
the upcoming weekend. This will be the coolest weather so far
for this Fall season with low temperatures this weekend near
the freezing mark especially west of the I-95 Corridor.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 900 PM Tuesday...Embedded mid-level s/ws moving within
fast 500mb flow, will help drive a sfc cold front, currently
across the northern portions of the FA from Cherry Point across
Lumberton to Bennettsville, southward across the FA and local
waters overnight to a Charleston to Augusta line. The majority
of the pcpn will be north of the front as it drops southward.
Looking at overrunning type pcpn in the form of light rain
and/or drizzle. Dynamics from one of those embedded s/ws will
result in the best chances for pcpn occurring from late this
evening through daybreak Wed, with the highest rainfall amounts
of up to 0.15 inches, running along the northern border of the
ILM CWA. Have worked the POPs close to the latest runs of the
HRRR model. Temperatures will drop to their lows by daybreak Wed
and not push much hier from there for Wed maxes.
Previous...................................................
As of 300 PM Tuesday...H5 zonal flow, with embedded impulses,
will persist through tonight into Wed ahead of a positively
tilted trough positioned to the west and northwest. A nearly
stationary front was located just north of the forecast area.
The zonal flow will inhibit any significant southward push of
this boundary through the early evening. Developing low pressure
off the Mid-Atlantic coast tonight will finally allow the front
to push north to south across the area from 06-12Z Wed. While
the post-frontal air-mass will not be dry much cooler
temperatures are on tap. In fact, tomorrow`s high temperature
will occur in the morning as cold air advection allows
temperatures to fall during the day. Overall, Wednesday`s high
temperature will be several categories below normal (normal is
around 70 at the coast to the upper 60s inland). Rainfall
chances will increase through the evening, but more-so
overnight. Scattered to numerous showers, with isolated tstms
possible will become increasingly stratified Wednesday.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...Chief weather caption this period, `cool
and wet`, as widespread, post-frontal over-running strengthens
Wednesday night, ahead of an approaching short-wave. Upper
support and deepening moisture will bring the heart of QPF
tallies on Thursday as the short-wave axis transits the area.
Damp and blustery NE winds and overcast conditions will lessen
diurnal temperature ranges this period and we essentially are
looking at 40s and 50s most of this period to accompany the rain
and periods of drizzle. Rain amounts Wednesday night through
Thursday night will range from 3/10ths to 6/10ths, which after a
period of relative dryness will be welcomed by the ground.
Winds will on occasion gust to 25 mph at the beaches and ICW
this period and the surf will be rough.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 300 PM Tuesday...Very fall-like this period with high
pressure dominating the synoptic regime. However, this high will
likely develop as a wedge during the weekend bringing low
clouds, abnormally cool temperatures, and periods of
mist/drizzle possible, especially late Saturday into Sunday.
Ahead of this wedge, Friday will likely be a pleasant day with
temps near seasonable norms and abundant sunshine as the
relatively low- amplitude flow blocks the cold air across New
England from flooding into the Southeast. On Saturday, the
surface high wedges down the coast while the mid- level flow
amplifies downstream from a shortwave digging into the OH VLY.
This creates much cooler temperatures and mins Saturday morning
will fall into the low 30s, with frost possible away from the
coast. Additionally, this setup supports an overrunning wedge,
and while soundings and time-heights show only shallow moisture,
some light showers are possible late Sat into Sun, along with
temps well below climo. This shortwave will push a weak front
across the Carolinas late Sunday into Monday eroding the wedge.
The GFS/ECM diverge at this point with the GFS faster and drier
with the FROPA, while ECM is slower and more moist. The key
difference appears to be strength of the trough, but in the fast
flow expect the GFS may be more correct and is preferred attm.
Behind this front, cool and dry conditions will return with
temps recovering to near climo by Tuesday.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
As of 00Z...A fairly significant cold front will drop south through
the region through the overnight hours. Look for post frontal
conditions of a moderate north wind, ceilings lowering to IFR, with
deteriorating visibilities on Wednesday. FLO observations will be
missing the visibility, so will not be amending for this condition.
Wednesday will be a rather raw day with continued IFR conditions and
northerly winds.
Extended Outlook...Mainly MVFR ceilings/tempo IFR Wed with
showers through Thursday. MVFR becoming VFR Friday and
continuing through Sunday.
&&
.MARINE...
NEAR TERM /THROUGH WEDNESDAY/...
As of 900 PM Tuesday...At the moment, the WSW to ENE oriented
sfc cold front has reached the Cape Hatteras to Cherry point to
Lumberton line. The front will continue to sink southward
overnight, reaching the Charleston to Augusta line a few hours
after daybreak Wed. The sfc pg will tighten after it`s passage
and combined with CAA, looking at northerly winds in the 15 kt
range occasionally to 20 kt and hier gusts due to the air-sea
interaction with local SSTs still around 70 degrees. Significant
seas will start off 1 to 3 ft and build only to 2 to 4 ft due
to a limited fetch to build upon under northerly winds.
Previous...................................................
As of 300 PM Tuesday...Variable winds 10 knots or less will
become southwesterly during the afternoon and evening. The wind
will turn north-northeasterly and increase overnight for the
Cape Fear waters, and toward day break for the southern waters.
North to northeast flow will persist during Wednesday all waters
as a ridge of high pressure takes hold across the Southeast U.S.
Seas around 2 ft will prevail this afternoon, then increase in
the wake of the front through Wednesday. Scattered to numerous
showers possible tonight, with isolated tstms.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...`Exercise Caution` or `Small Craft
Advisory` conditions possible this period, as NE winds behind a
cold front produce rough ocean conditions. Seas at a minimum of
3-5 feet expected, and closer to 3-4 feet SC waters, with
occasional gusts to 25 KT certainly believable given relatively
warm waters still in place. Not expecting an improving trend
this period, as winds remain elevated 15-20 KT and gusty.
Occasional rain and drizzle with mist may reduce visibilities to
1 NM or less at times. Dominant wave periods of 5-6 seconds
will produce steep wave conditions.
LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 300 PM Tuesday...High pressure ridging down the coast will
keep N/NE winds ongoing across the waters late week and through the
upcoming weekend. The strongest of these winds will occur late
Friday and through Saturday, as the gradient pinches around the
periphery of a short lived wedge setup. During this timeframe, wind
speeds will climb to 20-25 kts and drive seas to 4-6 ft, and an
SCA is likely. Otherwise, during Friday and Sunday, wind
direction remains N/NE but with speeds at 10-15 kts and slightly
lower amplitude wave heights, with a NE wind wave likely the
dominant wave group in the spectrum.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH/SRP
SHORT TERM...MJC
LONG TERM...JDW/CRM
AVIATION...DL
Area Forecast Discussion
National Weather Service Jackson MS
956 PM CST Tue Nov 7 2017
.UPDATE...
Updated for evening discussion.
&&
.DISCUSSION...
Main focus tonight continues on the cold front slowly trudging
southward through our area. Latest surface analysis and obs
indicate the front located over far southeastern areas of the
region, continuing its movement southward out of the CWA
overnight. Cloudiness extending behind the front across most of
the CWA along with a few showers will remain likely throughout the
night. HiRes guidance suggests potential for shower development
in areas along/near the I-20 corridor in association with a subtle
disturbance embedded in the flow aloft swinging through during
the hours just before daybreak. Fog does not appear to be as
widespread a threat as previous nights but low stratus will be
possible near the frontal boundary in southern locations. Cooler
air has begun to filter in behind the front, with temps in the
northern counties already in the low to mid 50s. Expect overnight
low temps ranging from lower 50s in northern locations to upper
50s to around 60 in southern locations. Winds will become
northerly areawide as the front clears the region.
Prior discussion below:
Tonight through Tuesday: Latest Rap and Satellite imagery showed
flat ridging through the atmosphere. A slow moving cold front was
slowly making its way across the region. Temperatures to the north
of the front were in the 60s and upper 50s. To the south of the
boundary readings were in the 70s to lower 80s. Area radars had
showers just ahead of the front near TVR to approaching JAN to
around GTR.
For tonight latest CAM guidance shows some light rain developing
from west to east overnight. The front will be positioned south of
the region. Isentropic lift will bring back the rain ahead of an
approaching shortwave. There may be some patchy fog in the
southeast near the frontal boundary prior to dawn, but will lift
by 14z. The light rain will increase in coverage on Wednesday as
the shortwave pushes into the Lower Mississippi Valley. Rainfall
amounts do not look very impressive. It should be a steady light
rain that should soak into the soil some. Looking at temperatures
lows will be in the lower 50s north to the lower 60s southeast.
Highs on Wednesday will be more seasonable with readings from the
middle 50s northwest to the middle 60s southeast. /17/
Wednesday night through early next week:
The shortwave will be on our western doorstep by 00Z Thursday.
Rain from this system will spread eastward overnight and will exit
our region Thursday after dawn. The overall setup of this system
suggests a more stratiform rainfall vs. convective and the models
continue their downward trend of potential rain intensity.
Therefore, the total precip amounts are not expected to be more
than an inch across the area. As the system clears the area on
Thursday, northerly surface flow continues to bring cooler
temperatures to the region. Upper level flow shifts to zonal and
through the rest of the week, temps remain very seasonal. On
Sunday the next system is projected to affect us. Models continue
to show some slight differences in evolution but agree that a cold
front will pass through with some rain on Sunday at this point.
This round of models did not necessarily show a reinforcing cold
shot behind the front, but temps going into next week do appear
to be near normal for this time of year. /10/
&&
.AVIATION...
00Z TAF discussion:
A weak cold front, extending from NMM to ESF, will continue to
slowly move south, finally pushing through HBG by 08/04Z. In its
wake, MVFR/IFR ceilings with patchy fog will overspread all TAF
sites and persist through the end of the period. /26/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 55 58 48 64 / 58 66 62 24
Meridian 57 61 48 64 / 47 59 64 34
Vicksburg 53 56 47 64 / 55 73 65 14
Hattiesburg 63 65 52 65 / 15 45 59 37
Natchez 55 57 48 63 / 26 58 59 19
Greenville 50 54 44 62 / 17 75 74 4
Greenwood 51 55 44 63 / 12 75 78 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
Area Forecast Discussion
National Weather Service Melbourne FL
837 PM EST Tue Nov 7 2017
.UPDATE...
Tonight...After 3 mornings with fog/stratus and a weakening high
pressure ridge across the local area, persistence would argue for
another round overnight. Generally, air masses that produce fog
will continue to do so until replaced by different one. However,
MOS has really backed off of fog formation.
We did get a bit of an air mass change this afternoon as drier air
above the surface mixed down and produced surface dew points several
degrees lower than yesterday. The GFS forecast soundings don`t show
low level saturation late tonight, but the visibility forecast from
the HRRR model and local WRF still have a few areas of fog, so will
maintain patchy fog in the forecast.
Weakening northerly low level flow has been pushing a few light
showers down the Gulf Stream. The HRRR and local WRF don`t show
much shower activity lingering overnight, but will leave a small PoP
for the far south coast into the early morning.
&&
.AVIATION...
VFR through this evening. MOS guidance does not show visibility and
ceilings nearly as low as recent mornings. Therefore, have just a
mention of MVFR in the TAFs, except at KLEE. The fog/stratus Wed
morning will dissipate quickly again.
&&
.MARINE...
Tonight-Wednesday...Good boating conditions with weakening high
pressure ridge over the waters. Winds will be less than 10 knots
and seas 2-3 feet.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Lascody/Sedlock
Area Forecast Discussion
National Weather Service New York NY
936 PM EST Tue Nov 7 2017
.SYNOPSIS...
A weak wave of low pressure moves well south and east of Long
Island through overnight. High pressure to the north gradually
builds in Wednesday into Wednesday night. High pressure over the
area on Thursday gives way to an approaching arctic cold front,
which will pass through the area late Thursday night. High
pressure then returns for the weekend before giving way to
another frontal system late Sunday into Monday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Have continued with slight speed up of system heading offshore
to the ENE. Adjusted POPs down a little sooner as per latest
radar trends, along with latest HRRR and RAP guidance. Also
adjusted temps to go with latest trends which have been a bit
colder for the overnight in N & NW sections. Northern zones in
CT see a mix of rain and snow before precip ends with no
accumulation expected as moisture exits as colder and drier air
wraps in behind the departing system.
Minimum temperatures will range from the upper 30s to lower 40s
for NYC Metro Area and coastal regions to the lower 30s for
locations far N/W of NYC.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
In the upper levels, there is a split jet structure. Polar jet
moves into North Central U.S. Wednesday and into Great Lakes
Wednesday night and subtropical jet will be moving eastward from
Southeast into mid-Atlantic Wednesday through Wednesday night.
Dry weather will prevail for Wednesday and Wednesday night. The
surface low pressure area well southeast of the 40N/70W
benchmark will move east farther out into the Atlantic. Have
the clouds decreasing during the late morning and into the early
afternoon now with high pressure gradually building in from the
north. Have now gone with more clearing for Wednesday night
with the high continuing to build in. The downward trend with
winds will continue as well, making for more radiational cooling
Wednesday night.
Maximum temperatures Wednesday will be limited due to cold air
advection from the backing of winds from low to mid levels. The
NE flow will keep maximum temperatures in the upper 40s to lower
50s. A blend of 1/3 NAM12 and 2/3 ECS guidance was used. For
Wednesday night, a blend of 1/2 ECS and 1/2 MET guidance was
used that conveys a range of lows from mid and upper 20s for
rural interior locations to low 40s in NYC.
For Wednesday night there is forecast areas of frost and patchy
frost across much of the region. Coastal CT and Suffolk County
NY have patchy frost but there is potential this could expand
in coverage in subsequent forecasts.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
***Record Cold Friday Night***
A digging upper trough across eastern Canada and into the
northeast quarter of the nation will send an arctic cold front
through the area late Thursday night. There is a good likelihood
of record cold Friday night with daytime highs Friday struggling
to get out of the 30s most locations. Readings will be be 15 to
20 degrees below normal.
Thereafter, the upper flow flattens with a more zonal flow to
follow. This will allow for a gradual moderation of
temperatures through early next week with a return to more
seasonable temperatures. High pressure will prevail through the
first half of the weekend and then retreats offshore Sunday
ahead of a fast moving frontal system over the Midwest and Great
Lakes. There are some timing and magnitude issues amongst the
global models with this system with the GFS on the faster side
of the envelope. Preference at this time was to go with model
consensus forecast with the frontal system approaching the area
Sunday night and then slowly passing to the east on Monday.
There is a chance of showers from Sunday afternoon into Monday.
Rainfall amounts appear to be light at this time. The 12Z ECMWF
places more emphasis on the southern branch energy, with a
slower progression of the system and higher rainfall amounts (up
to half an inch). Model trends will be watched, but the nature
of flow is more progressive and less amplified.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Low pressure tracks well to the southeast of Long Island
tonight. Weak high pressure builds in from the west on
Wednesday.
Primarily VFR this evening, with occasional periods of MVFR.
Cannot rule out a few flakes of snow or sleet pellets mixed in
with predominate rain through around 4-5z at northern/city
terminals and 6-7z at Long Island/Eastern CT Terminals. Should
then see a period of MVFR ceilings overnight, giving way to VFR
throughout by around 12z Wednesday.
Winds N-NNE mainly around 10KT overnight/Wednesday morning.
Winds diminish and back slightly to more N-NNW by late Wednesday
afternoon. Winds should become light and variable at inland
terminals by late afternoon as well.
.OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
.Wednesday night-Thursday night...Most likely VFR, with a low
chance of MVFR conditions Thursday afternoon/evening. S-SW winds
G15-25KT possible Thursday evening. W-NW winds G20-30KT possible
late Thursday night.
.Friday-Saturday night...VFR. NW winds G20-30+KT possible
Friday and Friday night.
.Sunday...MVFR or lower possible. SW winds G15-25KT possible.
&&
.MARINE...
The pressure gradient tightens as a low pressure area moving
well south of Long Island deepens tonight. The low tracks
farther into the open Atlantic Wednesday while slightly
deepening. Weak high pressure to the north will gradually build
in Wednesday into Wednesday night.
A gusty N-NE flow develops going into tonight with SCA wind
gusts becoming likely for all waters. On the ocean, boundary
layer winds mixing down could result in a few spots with some
brief gales but not enough temporal or spatial coverage to
warrant any gale headlines. Otherwise, expect SCA conditions to
continue tonight and then lingers mainly on the ocean for
Wednesday, although expect some SCA gusts on Eastern Long
Island Sound and Eastern Long Island Bays for Wednesday
morning. Conditions lower to below SCA Wednesday night with
winds as the pressure gradient decreases with high pressure
gaining control but the ocean seas will likely remain elevated
in SCA range.
So SCA headlines are as follows: All waters for tonight, ocean
and Eastern Long Island Sound and Eastern Long Island Bays
Wednesday morning, and then just the ocean for the rest of
Wednesday and Wednesday night.
Conditions should remain below SCA on the waters Thursday as
weak high pressure continues to be across the waters. An arctic
front will cross the region late Thursday night, with SCA
conditions expected on all waters into Friday evening. There is
a low potential for gale gusts.
Conditions will improve Saturday as high pressure builds into
the region with conditions forecast to return to sub SCA.
&&
.HYDROLOGY...
QPF is expected to range between 1/3 and 3/4 inch through early
Wednesday with no hydrologic impacts expected.
Rainfall amounts Sunday night into Monday are forecast to be
under a quarter inch. The 12Z ECMWF is more aggressive with a
slower frontal wave with the potential for higher rainfall
amounts. Model trends will be watched, but the nature
of flow is more progressive and less amplified.
&&
.TIDES/COASTAL FLOODING...
In spite of a northerly flow, an average of guidance plus
current anomalies points to the likelihood of minor coastal
flooding during Wendesday`s late morning to early afternoon high
tide cycle as low pressure pulls away to the southeast. Minor
coastal flooding is expected along the South Shore Back Bays of
Nassau County, Queens and Brooklyn as well as along parts of
southern NY Harbor. An advisory has been issued for these
locations, and a statement has been issued for southwestern
Suffolk county where minor flooding is expected to be isolated
and barely met.
Statements or possibly even advisories may be needed for the
high tide cycle near noontime for Southern Nassau and Southern Queens.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Coastal Flood Advisory from 10 AM to 1 PM EST Wednesday for
NYZ074-075-178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST Wednesday for ANZ335-338-
345.
Small Craft Advisory until noon EST Wednesday for ANZ330-340.
Small Craft Advisory until 6 AM EST Thursday for ANZ350-353-
355.
&&
$$
SYNOPSIS...JM/DW
NEAR TERM...JE
SHORT TERM...JM/JE
LONG TERM...DW
AVIATION...Maloit
MARINE...JM/DW
HYDROLOGY...JM/DW
TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Mount Holly NJ
951 PM EST Tue Nov 7 2017
.SYNOPSIS...
Low pressure emerges off the Mid-Atlantic coast early this evening,
then moves out to sea through tonight. High pressure builds into our
region Wednesday before weakening during Thursday. A strong cold
front moves through Thursday night followed by cold Canadian high
pressure on Friday and Saturday. The next cold front moves through
late Sunday into Monday, then high pressure returns for Tuesday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Precipitation continues to move to the east this evening and
should gradually move towards the coast and offshore through
tonight.
Snowfall totals have been around an inch in parts of the
Southern Poconos with snow reported mainly in the higher
elevations.
The surface low remains to our south and will continue to lift
northeast and away from the region through the overnight
period. The low appears to be in good agreement with the GFS and
RAP and we continue to follow that guidance.
Temperatures overnight will remain cold, especially across the
north, with lows in the upper 20s to lower 30s. As you head
south of I-78, temperatures will remain more in the mid 30 to
lower 40s, with mid 40s along the southern NJ and DE coasts.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
As the low moves further away, drier and cooler air will move into
the region. The one exception is in southern DE, where rain may
linger through the day thanks to continued onshore flow. Any
precipitation during the day tomorrow though should be light.
Temperatures tomorrow should be slightly below normal, with highs
ranging from the mid 40s to lower 50s.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Summary...Strong cold front Thursday night ushers in arctic air for
Friday and Saturday, followed by some moderation through early next
week.
Synoptic Overview...A potent upper-level trough arriving into the
Pacific Northwest Wednesday night into Thursday builds a ridge into
western Canada. This forces a significant digging trough downstream,
which overtakes the Great Lakes and Northeast at the end of the week
before lifting out over the weekend. The flow looks to briefly turn
more zonal before another upper-level trough arrives late in the
weekend into early next week. A couple of cold fronts look to move
through; a strong one Thursday night then another arrives later
Sunday into Monday. The first cold front will deliver a shot of
arctic air for a couple of days.
For Wednesday night and Thursday...A short wave trough will shift
offshore Wednesday night, allowing low pressure offshore to move
farther away. This should be far enough south and east to keep the
lingering northwestern edge of the rain pretty out of our area to
start Wednesday night. Otherwise, surface high pressure builds into
the area overnight Wednesday before gradually shifting east and
weakening during Thursday. A potent upper-level trough will be
digging across the Great Lakes Thursday and then the Northeast at
night. This will drive surface low pressure to our north, however a
strong cold front will sweep through Thursday night. The main
forcing looks to be tied to the northern part of the front closer to
the surface low, with the guidance indicating the potential for a
narrow line of low-topped convection with it. This may glance our
northwestern zones Thursday night, however the moisture with a
southern extent looks to be more limited. The main impact with this
front will be a strong surge of cold air advection in its wake,
along with substantial dry air advection. This will set the stage
for much colder air arriving.
For Friday and Saturday...As a robust upper-level trough swings
across New England Friday, deepening surface low pressure will be
north of New England while surface high pressure builds across the
Great Lakes and Ohio Valley. This will allow for a tight pressure
gradient across our region within a cold air advection regime. The
end result will be a gusty north-northwest wind during Friday with
peak gusts to around 30 mph. The airmass looks very dry,
characteristic of arctic origin, therefore dew points will be down
into the teens and even single numbers.
The center of the surface high builds in Friday night and Saturday,
allowing the winds to diminish. The airmass will be rather cold
already, however if the winds decouple enough or even faster Friday
night then temperatures will be even colder. At least the more
sheltered areas should see a drop off in the winds quicker and
therefore went a bit colder with the low temperatures. Our current
forecast places some record low temperatures in jeopardy for early
Saturday morning. Overall, a widespread hard freeze is expected
Friday night. The growing season is still technically active for
extreme southeastern Pennsylvania, southern New Jersey, Delaware and
northeastern Maryland. As a result, the need for a Freeze Watch to
Warning is expected. Daytime high temperatures for both of these
days are expected to only be in the 30s and 40s.
For Sunday through Tuesday...High pressure retreats eastward with
its center mostly becoming situated close to the Canadian Maritimes
Sunday. The earlier zonal flow amplifies with an upper-level trough
moving through the Great Lakes region on eastward Sunday into
Monday, driving a cold front across our area late Sunday. There are
some differences among the model guidance on the strength of this
feature and how much precipitation occurs. We will maintain some
chances for precipitation with it, however it may be delayed some to
allow for enough warming to prevent any frozen/freezing
precipitation up north at the onset. High pressure then builds into
our area during Tuesday as the flow may tend to become more
zonal.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Occasional MVFR/IFR visibility and ceilings will
continue through at least 03Z. After 03Z, the rain is expected
to taper off from west to east. As the rain ends, there may be a
brief period of MVFR visibilities but overall most areas should
see rapid improvement. Ceilings may take longer to
clear than the visibilities but should gradually return to VFR
by 12Z. However, at KACY and KMIV persistent onshore flow could
help to keep the low clouds through the overnight and into early
Wednesday.
North to northeasterly winds will be around 10 to 15 knots this
evening with gusts up around 20 knots possible, mainly at KACY
and KMIV.
Wednesday...MVFR conditions early should clear quickly and
become VFR. However, with the prolonged north to northeast flow,
KACY and KMIV may see MVFR conditions linger through the
morning and possibly into the afternoon, especially at KACY
where VFR may not occur until later in the day. Northeast winds
around 10 knots or less across the terminals.
OUTLOOK...
Wednesday night and Thursday...VFR with ceilings at times mainly at
and above 5000 feet. Northeast winds 5 knots or less becoming
southwest Thursday afternoon, then west to northwest Thursday night
and increasing to near 10 knots.
Friday and Saturday...Mainly VFR. North-northwest wind gusts to
around 25 knots Friday, then lighter winds Friday night and Saturday.
Sunday...Possible times of MVFR conditions with a chance of
showers.
&&
.MARINE...
SCA conditions are imminent on both the Delaware Bay and the
coastal waters. On the DE and southern NJ Atlantic coastal waters,
gale force gusts are likely after 00Z through at least 06Z. For the
remainder of the area, gusts are expected to be around or below 30
KT. Winds should begin to subside by day break, and the Bay may be
below SCA criteria as early as late Wednesday morning. On the
coastal waters however, SCA conditions are expected to continue
through the day.
OUTLOOK...
Wednesday night and Thursday...The winds and seas will be
diminishing, however a Small Craft Advisory may be needed for a time
especially for the Atlantic coastal waters zones.
Thursday night through Friday night...Small Craft Advisory
conditions are expected due to strong cold air advection and deeper
mixing. North-northwest wind gusts up to 30 knots are anticipated,
however around daybreak Friday some gusts could reach to low-end
gale force. The winds gradually diminish Friday night as high
pressure arrives.
Saturday and Sunday...No headlines are anticipated as high pressure
initially over the area shifts to our northeast and east through
Sunday.
&&
.TIDES/COASTAL FLOODING...
A Coastal Flood Advisory was issued for the NJ and DE coast,
including the DE Bay, with minor tidal flooding expected to occur
with the Wednesday morning high tide. The astronomical tides
continue to remain high. With the continued north to northeast wind
on Wednesday, we will maintain a surge of between 1/2 and 1 ft above
the astronomical tide.
&&
.CLIMATE...
Record low temperatures for Saturday morning for several of our
sites are forecast to be challenged. The extent of the cold however
will depend on how quick the winds diminish Friday night as high
pressure builds in.
The daily record low temperatures for 11/11 are listed below for all
of our climate sites.
Site Daily Record Low Year Set
Temp for 11/11 (F)
ACY 22 1973
PHL 21 1961
ILG 22 1961
ABE 19 1954 and 1956
TTN 25 1973 and 1987
GED 21 1973
RDG 18 1973
MPO 11 1956
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory from 9 AM to 4 PM EST Wednesday for
NJZ012>014-020>027.
DE...Coastal Flood Advisory from 9 AM to 4 PM EST Wednesday for
DEZ002>004.
MD...None.
MARINE...Gale Warning until 6 AM EST Wednesday for ANZ452>455.
Small Craft Advisory until 6 PM EST Wednesday for ANZ431-450-
451.
Small Craft Advisory until noon EST Wednesday for ANZ430.
&&
$$
Synopsis...Gorse
Near Term...Johnson/Meola
Short Term...Johnson
Long Term...Gorse
Aviation...Gorse/Johnson/Meola
Marine...Gorse/Johnson
Tides/Coastal Flooding...
Climate...
Area Forecast Discussion
National Weather Service Shreveport LA
1002 PM CST Tue Nov 7 2017
.DISCUSSION...
The cold front has finally cleared the region to the S into far SE
TX and Cntrl LA this evening, with the post-frontal cooler air
slowly beginning to deepen in its wake across the area. A
considerable post-frontal stratus shield will linger overnight
though, which should help limit the extent of the temp fall as
the cold advection weakens. The regional mosaic radar imagery
indicates sct areas of -RA over Cntrl TX migrating E into portions
of Deep E TX, although the sfc obs have not reflected much of any
of this actually reaching the ground. The latest run of the HRRR
suggests that this -RA should continue to spread E into Ncntrl LA
after 06Z as ripples in the zonal flow aloft over the Srn
Plains/Lower MS Valley continues to shift E. However, our focus
will shift to our W late tonight as areas of SHRA develops over
Wrn and N TX, ahead of an upper trough now entering the Four
Corners Region. Isentropic forcing along the 300-310K surfaces
will begin to spread E across N TX late tonight/Wednesday morning,
some of which will begin to spill into portions of NE TX/SE OK/SW
AR. The HRRR is most aggressive with the SHRA, although the
latest run has backed off on this (more in consensus with the 00Z
NAM/18Z GFS), and thus have maintained mid chance pops for these
areas. Did lower pops a tad elsewhere to low chance given the
lesser deep lyr forcing/lack of isentropic lift, but SHRA should
quickly ramp up from W to E Wednesday morning as the isentropic
forcing spreads E near and N of the H850 front over Deep E
TX/Cntrl LA. Given the QPF consensus amongst the short term progs,
have maxed out the categorical pops across much of NE TX/Srn
AR/Extreme Nrn LA, with temps not expected to recover much during
the day from the morning low temps.
As for min temps, did make some minor downward tweaks per the 03Z
obs, which were 1-2 degrees cooler than the gridded temps.
Otherwise, the remainder of the forecast is in good shape.
Zone update already out...grids will be available shortly.
15
&&
.PREV DISCUSSION... /issued 555 PM CST Tue Nov 7 2017/
AVIATION...
For the 08/00z TAFs, IFR flight conditions already prevail in most
areas with the exception of KTYR and locations in Texas and
Louisiana south of Interstate 20. However, ceilings and
visibilities will continue to deteriorate, and IFR conditions
should prevail areawide by 08/06z. Patchy fog, light rain, and
drizzle is also likely across much of the area. A large area of
rain will develop and spread eastward across the region after
08/12z. All TAF sites will be affected by the rain, and the
precipitation should persist through at least the end of the
period. IFR, and occasional LIFR, conditions will also persist.
CN
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 52 54 45 62 / 30 100 80 10
MLU 52 54 46 63 / 30 90 80 10
DEQ 50 50 40 62 / 40 90 50 10
TXK 49 51 43 61 / 40 100 60 10
ELD 49 52 42 61 / 30 100 80 10
TYR 48 52 46 60 / 30 100 80 10
GGG 51 53 45 61 / 30 100 80 10
LFK 55 58 49 62 / 30 90 80 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
15/09
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