Alert archive / New Jersey / Winter Weather Advisories in 2017

Winter Weather Advisory 16, NWS Philadelphia/Mount Holly

December 13, 201710 counties in New Jersey; 10 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this winter weather advisory at Dec 13, 2017, 3:28 PM EST for 10 counties in New Jersey; 10 counties in Pennsylvania. It took effect at Dec 13, 2017, 8:00 PM EST. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
Dec 13, 2017, 3:28 PM EST (20:28 UTC)
In effect from
Dec 13, 2017, 8:00 PM EST
Expired
Dec 14, 2017, 7:44 AM EST
In force
12 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 79 km from the middle of the area, began a volume at 20:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.5 hours before the alert went out and 196 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2017-12-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2017-12-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -185 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1287 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-185 m²/s²
0-3 km storm-relative helicity
-98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

878 
WWUS41 KPHI 132028
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
328 PM EST Wed Dec 13 2017

NJZ001-007-009-PAZ054-055-060>062-103-105-141100-
/O.NEW.KPHI.WW.Y.0003.171214T0100Z-171214T1500Z/
Sussex-Warren-Hunterdon-Carbon-Monroe-Berks-Lehigh-Northampton-
Western Montgomery-Upper Bucks-
Including the cities of Newton, Washington, Flemington, 
Jim Thorpe, Stroudsburg, Reading, Allentown, Bethlehem, Easton, 
Collegeville, Pottstown, Chalfont, and Perkasie
328 PM EST Wed Dec 13 2017

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
10 AM EST THURSDAY...

* WHAT...Snow expected. Temperatures are cold enough for snow to 
  stick on contact on untreated roads, resulting in slippery 
  travel conditions. Total snow accumulations of 2 to 3 inches are
  expected.

* WHERE...Portions of northwest New Jersey and eastern 
  Pennsylvania.

* WHEN...From 8 PM this evening to 10 AM EST Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times. Most of the snow will fall prior to daybreak Thursday. Be
  prepared to add extra travel time in the morning. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

PAZ070-071-101-102-104-106-141100-
/O.NEW.KPHI.WW.Y.0003.171214T0100Z-171214T1500Z/
Delaware-Philadelphia-Western Chester-Eastern Chester-
Eastern Montgomery-Lower Bucks-
Including the cities of Media, Philadelphia, Honey Brook, Oxford,
West Chester, Kennett Square, Norristown, Lansdale, Morrisville, 
and Doylestown
328 PM EST Wed Dec 13 2017

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
10 AM EST THURSDAY...

* WHAT...Snow expected. Temperatures are cold enough for snow to
  stick on contact on untreated roads, resulting in slippery
  travel conditions. Total snow accumulations of 1 to 2 inches 
  are expected.

* WHERE...Portions of southeast Pennsylvania.

* WHEN...From 8 PM this evening to 10 AM EST Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at
  times. Most of the snow will fall prior to daybreak Thursday. Be
  prepared to add extra travel time in the morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

For more information from the National Weather Service visit
www.weather.gov/phi/winter
4 follow-up statements
269 
WWUS41 KPHI 132335
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
635 PM EST Wed Dec 13 2017


NJZ008-010-012-015-141145-
/O.EXA.KPHI.WW.Y.0003.171214T0100Z-171214T1500Z/
Morris-Somerset-Middlesex-Mercer-
Including the cities of Morristown, Somerville, New Brunswick, 
and Trenton
635 PM EST Wed Dec 13 2017

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM EST THURSDAY...

* WHAT...Snow expected. Temperatures are cold enough for snow to
  stick on contact on untreated roads, resulting in slippery
  travel conditions. Total snow accumulations of 2 to 3 inches 
  are expected.

* WHERE...Morris, Somerset, Middlesex and Mercer counties.

* WHEN...Until 10 AM EST Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.Most of the snow will fall prior to daybreak Thursday. Be
  prepared to add extra travel time in the morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

NJZ017>019-141145-
/O.EXA.KPHI.WW.Y.0003.171214T0100Z-171214T1500Z/
Gloucester-Camden-Northwestern Burlington-
Including the cities of Glassboro, Camden, Cherry Hill, 
Moorestown, and Mount Holly
635 PM EST Wed Dec 13 2017

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM EST THURSDAY...

* WHAT...Snow expected. Temperatures are cold enough for snow to
  stick on contact on untreated roads, resulting in slippery
  travel conditions. Plan on slippery road conditions. Total 
  snow accumulations of up to two inches are expected.

* WHERE...Gloucester, Camden and Northwestern Burlington 
  counties.

* WHEN...Until 10 AM EST Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at
  times. Most of the snow will fall prior to daybreak Thursday. 
  Be prepared to add extra travel time in the morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

NJZ001-007-009-PAZ054-055-060>062-103-105-141145-
/O.CON.KPHI.WW.Y.0003.171214T0100Z-171214T1500Z/
Sussex-Warren-Hunterdon-Carbon-Monroe-Berks-Lehigh-Northampton-
Western Montgomery-Upper Bucks-
Including the cities of Newton, Washington, Flemington, 
Jim Thorpe, Stroudsburg, Reading, Allentown, Bethlehem, Easton, 
Collegeville, Pottstown, Chalfont, and Perkasie
635 PM EST Wed Dec 13 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM EST
THURSDAY...

* WHAT...Snow expected. Temperatures are cold enough for snow to 
  stick on contact on untreated roads, resulting in slippery 
  travel conditions. Plan on slippery road conditions,
  including during the morning commute on Thursday. Total snow
  accumulations of 2 to 4 inches are expected.

* WHERE...Portions of northern and northwest New Jersey and east 
  central, northeast and southeast Pennsylvania.

* WHEN...Until 10 AM EST Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at
  times. Most of the snow will fall prior to daybreak Thursday. 
  Be prepared to add extra travel time in the morning. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

PAZ070-071-101-102-104-106-141145-
/O.CON.KPHI.WW.Y.0003.171214T0100Z-171214T1500Z/
Delaware-Philadelphia-Western Chester-Eastern Chester-
Eastern Montgomery-Lower Bucks-
Including the cities of Media, Philadelphia, Honey Brook, Oxford,
West Chester, Kennett Square, Norristown, Lansdale, Morrisville, 
and Doylestown
635 PM EST Wed Dec 13 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM EST
THURSDAY...

* WHAT...Snow expected. Temperatures are cold enough for snow to 
  stick on contact on untreated roads, resulting in slippery 
  travel conditions. Plan on slippery road conditions. Total 
  snow accumulations of up to two inches are expected.

* WHERE...Portions of southeast Pennsylvania.

* WHEN...Until 10 AM EST Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at
  times. Most of the snow will fall prior to daybreak Thursday. Be
  prepared to add extra travel time in the morning. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

For more information from the National Weather Service visit
www.weather.gov/phi/winter
531 
WWUS41 KPHI 140836
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
336 AM EST Thu Dec 14 2017

NJZ001-007>010-012-015-PAZ054-055-060>062-103-105-141500-
/O.CON.KPHI.WW.Y.0003.000000T0000Z-171214T1500Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Carbon-
Monroe-Berks-Lehigh-Northampton-Western Montgomery-Upper Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, New Brunswick, Trenton, Jim Thorpe, 
Stroudsburg, Reading, Allentown, Bethlehem, Easton, Collegeville,
Pottstown, Chalfont, and Perkasie
336 AM EST Thu Dec 14 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM EST THIS
MORNING...

* WHAT...Snow occurring. Plan on slippery road conditions, 
  including during the morning commute. Additional snow 
  accumulations of up to one inch are expected.

* WHERE...Portions of central and northwest New Jersey and
  southeast Pennsylvania.

* WHEN...Until 10 AM EST this morning.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

NJZ017>019-PAZ070-071-101-102-104-106-141500-
/O.CON.KPHI.WW.Y.0003.000000T0000Z-171214T1500Z/
Gloucester-Camden-Northwestern Burlington-Delaware-Philadelphia-
Western Chester-Eastern Chester-Eastern Montgomery-Lower Bucks-
Including the cities of Glassboro, Camden, Cherry Hill, 
Moorestown, Mount Holly, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, Kennett Square, Norristown, Lansdale, 
Morrisville, and Doylestown
336 AM EST Thu Dec 14 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM EST THIS
MORNING...

* WHAT...Snow occurring, possibly during the morning commute. 
  Additional accumulations of a dusting to around an inch may 
  occur.

* WHERE...Portions of western New Jersey and southeast 
  Pennsylvania.

* WHEN...Until 10 AM EST this morning.

* ADDITIONAL DETAILS...Be prepared for slick roads during the
  morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for blowing snow means that
visibilities will be limited due to strong winds blowing snow
around. Use caution when traveling, especially in open areas. The
latest road conditions for the state you are calling from can be
obtained by calling 5 1 1.

$$

For more information from the National Weather Service visit
www.weather.gov/phi/winter

CMS
504 
WWUS41 KPHI 140951
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
451 AM EST Thu Dec 14 2017

NJZ017>019-PAZ070-071-101-102-141100-
/O.CAN.KPHI.WW.Y.0003.000000T0000Z-171214T1500Z/
Gloucester-Camden-Northwestern Burlington-Delaware-Philadelphia-
Western Chester-Eastern Chester-
Including the cities of Glassboro, Camden, Cherry Hill, 
Moorestown, Mount Holly, Media, Philadelphia, Honey Brook, 
Oxford, West Chester, and Kennett Square
451 AM EST Thu Dec 14 2017

...WINTER WEATHER ADVISORY IS CANCELLED...

Though some flurries or a light snow shower may occur early this
morning, accumulating snowfall has generally ended. Therefore, the
winter weather advisory has been cancelled. However, slick roads
should be expected for this morning's commute. Use extra caution
traveling.

$$

NJZ001-007>010-012-015-PAZ054-055-060>062-103-105-141500-
/O.CON.KPHI.WW.Y.0003.000000T0000Z-171214T1500Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Carbon-
Monroe-Berks-Lehigh-Northampton-Western Montgomery-Upper Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, New Brunswick, Trenton, Jim Thorpe, 
Stroudsburg, Reading, Allentown, Bethlehem, Easton, Collegeville,
Pottstown, Chalfont, and Perkasie
451 AM EST Thu Dec 14 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM EST THIS
MORNING...

* WHAT...Snow occurring. Plan on slippery road conditions, 
  including during the morning commute. Additional snow 
  accumulations of up to one inch are expected.

* WHERE...Portions of central and northwest New Jersey and
  southeast Pennsylvania.

* WHEN...Until 10 AM EST this morning.

* ADDITIONAL DETAILS...Slick roads can be expected for the morning
  commute. Use extra caution traveling. Be prepared for reduced 
  visibilities at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

PAZ104-106-141500-
/O.CON.KPHI.WW.Y.0003.000000T0000Z-171214T1500Z/
Eastern Montgomery-Lower Bucks-
Including the cities of Norristown, Lansdale, Morrisville, 
and Doylestown
451 AM EST Thu Dec 14 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM EST THIS
MORNING...

* WHAT...Snow occurring, possibly during the morning commute.
  Additional accumulations under an inch are expected.

* WHERE...Eastern Montgomery and Lower Bucks Counties.

* WHEN...Until 10 AM EST this morning.

* ADDITIONAL DETAILS...Slick roads can be expected for the morning
  commute. Use extra caution traveling.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for blowing snow means that
visibilities will be limited due to strong winds blowing snow
around. Use caution when traveling, especially in open areas. The
latest road conditions for the state you are calling from can be
obtained by calling 5 1 1.

$$

For more information from the National Weather Service visit
www.weather.gov/phi/winter

CMS
537 
WWUS41 KPHI 141244
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
744 AM EST Thu Dec 14 2017


NJZ001-007>010-012-015-PAZ054-055-060>062-103>106-141345-
/O.CAN.KPHI.WW.Y.0003.000000T0000Z-171214T1500Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Carbon-
Monroe-Berks-Lehigh-Northampton-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, New Brunswick, Trenton, Jim Thorpe, 
Stroudsburg, Reading, Allentown, Bethlehem, Easton, Collegeville,
Pottstown, Norristown, Lansdale, Chalfont, Perkasie, Morrisville,
and Doylestown
744 AM EST Thu Dec 14 2017

...WINTER WEATHER ADVISORY IS CANCELLED...

The snow is ending across the area this morning. No additional
snowfall is expected today. However, untreated and less traveled
roads will still be slick. Use extra caution if traveling during
the morning commute.

$$

For more information from the National Weather Service visit
www.weather.gov/phi/winter

Klein

What forecasters said that day

The local office's own words before this winter weather advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this winter weather advisory went out at Dec 13, 9:31 AM EST, 5 hours 57 minutes earlier.

Area forecast discussion, Dec 13, 9:31 AM EST, 5 hours 57 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
931 AM EST Wed Dec 13 2017

.SYNOPSIS...
High pressure will slide across to the south of the region
today. A clipper system will cross the region late tonight into
Thursday. High pressure will return for Thursday night and
Friday. A low pressure system will move up the Mid Atlantic
coast on Friday, remaining well offshore. A brief return to high
pressure is expected for the weekend. Another system will
affect the region early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
With wind gusts across southern Delaware and parts of southeast
New Jersey falling below Wind Advisory criteria, will go ahead
and cancel the Wind Advisory. Will still have wind gusts 30-40
MPH through lunchtime, though.

Also, isolated snow showers will continue over the Poconos
through the late morning hours. Light accumulations are
possible, generally less than 1/2".

Otherwise, cold air advection continues with west-northwest
winds gusting 25-30 mph through this afternoon. Quite dry with
surface dewpoints generally in the single digits. Temperatures
in the 20s this morning will only top out around 30 this
afternoon, except for the Poconos, which is in the teens and may
only top out around 20. The resulting wind chill will stay in
the teens for most of the region, except for as low as 10 below
in the Poconos this morning, and then in the single digits this
afternoon.

Clouds may hang around the northern CWA for much of the day,
but the rest of the area should see some sunshine. Increasing
cloudiness near sunset will be possible as the next system makes
a rapid approach to the area.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
Clipper low should be entering the Mid-Atlantic region at the start
of the period, just downstream of a pivoting midlevel vort max in
the Great Lakes region. The surface low will weaken as it approaches
the spine of the Appalachians and redevelop offshore during the
overnight period, which suggests that the attendant precipitation
shield should be weakening as it approaches the CWA and
strengthening once it leaves the CWA (sorry, snow lovers).

Nevertheless, there will be snow overnight, but the combination of
waning dynamics, dry antecedent near-surface air, and orographic
shadowing should preclude snow amounts from exceeding a couple
inches to the northwest of the Fall Line and should generally be
under an inch to the southeast. Little if any snowfall is forecast
south of the Mason-Dixon Line. The snow should enter the region late
in the evening and be on the decrease by daybreak. Despite the light
amounts, the timing (and the subfreezing temperatures) suggests that
there will be impacts with the morning commute on Thursday. For
messaging purposes, it is important to stress that the lack of a
winter weather advisory (owing to light snow amounts) does not
equate to a lack of impacts. Some slick roads and treacherous travel
can be expected should the snow materialize as currently forecast.

Temperatures will not fall much from highs on Wednesday but should
drop a little bit during the evening hours, especially before the
denser cloud cover invades the region. Temperatures may reach their
minima prior to midnight before a slow rise in the warm-air
advection preceding the surface low's trek/redevelopment offshore
through the night.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
An unsettled pattern continues through the extended period with
several waves of low pressure slated to move through the region.

Thursday...The clipper system quickly crosses the region early
Thursday, along with a strong shortwave. Snow will be falling early
and may make for a slick morning commute. The snow will start to
taper off through Thursday morning and we should see it end by early
afternoon across the forecast area. Winds may be gusty along the
coast, especially in the morning, but should subside through the day
as the low moves further offshore. Daytime highs will be fairly
cold across the area. Highs will range from the lower 20s across the
southern Poconos and northwest New Jersey to lower 40s across
southern Delaware and extreme southern New Jersey.

Thursday night through Friday night...High pressure will make its
way into the area overnight and cross the region on Friday. A
coastal low develops along the Carolina coast and makes its way up
the Mid Atlantic coast. Additionally, a couple of shortwaves will
rotate through the area on Friday. The models continue to show this
system remaining offshore and out of our area. However, so moisture
may reach into our area and we could see some snow fall towards the
afternoon and into the evening. Some mixing along the coast will be
possible but it looks cold enough that the majority of the area will
see only snow fall. Snow should end from west to east Friday night
and fairly quickly as the system moves further away from the area
and out to sea.

Saturday through Sunday morning...High pressure will slide across
the eastern United States on Saturday, bringing us a nice day of
quiet weather. The weather should remain quiet through at least
Sunday morning. Warmer air will start to make its way towards the
region this weekend but we won't start to feel the difference until
Sunday.  Temperatures are expected to be in the 30s to lower 40s on
Saturday and in the upper 30s to upper 40s on Sunday.

Sunday afternoon through Tuesday...Another system will approach the
region sometime around Sunday night or Monday. The models diverge
with how to handle another clipper system to our north Sunday and a
developing low to our south. For now, will continue to mention the
chance for precipitation starting Sunday afternoon through Monday.
Warm air will move into the region in the southwesterly flow and we
may see a period of rain or mixed precipitation through the region.
Temperatures look to remain cold over the northwestern zones and
likely to remain all snow there. Plenty of uncertainty exists
bringing lower confidence through this period.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...VFR with west to northwest winds 15-20 kt with 25-35 kt
gusts. Winds may begin to diminish a bit after 18Z. High
confidence.

Tonight...Sub-VFR CIGs and especially VSBYs should be expected
with snow likely to most of the terminals through portions of
the night (general timing between 02Z and 10Z, with longer
durations likely north of PHL). Runway accumulations may occur,
but should be around an inch or less. Winds will begin from the
southwest around 10 kts but should become light and variable
from late evening onward. Medium confidence in CIGs/VSBYs (with
low confidence in occurrence/timing of snow); high confidence in
winds.

Outlook...

Thursday...MVFR or lower conditions possible in snow through
Thursday afternoon. Snow should clear out by 18Z and then mainly
VFR conditions expected. West to northwest winds around 10 to 15
knots. Confidence: Moderate

Friday...Mainly VFR conditions expected. MVFR or lower possible in
snow showers Friday afternoon and evening. Light winds.
Confidence: Low to Moderate

Saturday...Mainly VFR conditions expected. West to southwest winds
around 10 to 15 knots possible with higher gusts, mainly at KACY and
KMIV. Confidence: Low to Moderate

Sunday...Mainly VFR conditions expected. MVFR conditions in
snow/rain showers possible Sunday afternoon. Southwest winds around
5 to 10 knots. Confidence: Low

&&

.MARINE...
Gales continue across all marine zones at this time, with the
peak in the gusts likely through lunchtime. Latest model
forecasts a brief (around 6 hours) lull in winds (still
exceeding advisory thresholds) before increasing to near or just
above gale force off the Delaware coast again (albeit from
southwest winds rather than west/northwest), while areas farther
north likely stay at advisory levels.

Seas are running about a foot above model forecasts, so made
some adjustments to these through the late evening hours to
account for this.

At least small craft advisory conditions are expected tonight
as winds become more southwesterly in advance of the next
system. Gusts may reach gale-force again in the Delaware coastal
waters after midnight, but confidence is rather low at this
time. Some snow may develop, generally after midnight and
primarily for the New Jersey coastal waters, with visibility
restrictions likely should the snow materialize.

Outlook...

Thursday ...Small Craft Advisory conditions continue through
Thursday. Both winds and seas are expected to drop through the day,
falling below SCA criteria by Thursday evening.

Thursday night through Friday...Sub-advisory conditions are
expected.

Friday night through Saturday...Small Craft Advisory conditions
possible. West to northwest winds will gusts around 25 knots
possible. Seas will increase and near 5 feet.

Sunday...Sub-advisory conditions expected. Winds may near 25
knots and seas may near 5 feet late Sunday.

&&

.TIDES/COASTAL FLOODING...
The strong west to northwest winds occurring overnight have
lowered water levels on the tidal Delaware River. As these winds
are expected to continue through the day, water levels may be
low enough (i.e., around or below 2 feet below MLLW) to cause
some navigation issues during low tide this afternoon and this
evening. We have issued a special weather statement to address
this concern. Winds should diminish tonight, which will allow
water levels to return to more typical values.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Gale Warning until midnight EST tonight for ANZ450>453.
     Gale Warning until 6 PM EST this evening for ANZ430-431-454-
     455.

&&

Synopsis...Meola
Near Term...CMS/MPS
Short Term...CMS
Long Term...Meola
Aviation...CMS/Meola/MPS
Marine...CMS/Meola/MPS
Tides/Coastal Flooding...
Hazardous weather outlook, Dec 13, 9:21 AM EST, 6 hours 7 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
921 AM EST Wed Dec 13 2017

NJZ001-007>010-012-PAZ054-055-060>062-103-105-141500-
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Carbon-Monroe-
Berks-Lehigh-Northampton-Western Montgomery-Upper Bucks-
921 AM EST Wed Dec 13 2017

This Hazardous Weather Outlook is for northern New Jersey,
northwest New Jersey, east central Pennsylvania, northeast
Pennsylvania and southeast Pennsylvania.

.DAY ONE...Today and Tonight.

A period of accumulating snow is expected tonight, resulting in
hazardous travel conditions.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

DEZ001>004-MDZ008-012-015-019-020-NJZ013>027-PAZ070-071-101-102-104-
106-141500-
New Castle-Kent-Inland Sussex-Delaware Beaches-Cecil-Kent MD-
Queen Annes-Talbot-Caroline-Western Monmouth-Eastern Monmouth-Mercer-
Salem-Gloucester-Camden-Northwestern Burlington-Ocean-Cumberland-
Atlantic-Cape May-Atlantic Coastal Cape May-Coastal Atlantic-
Coastal Ocean-Southeastern Burlington-Delaware-Philadelphia-
Western Chester-Eastern Chester-Eastern Montgomery-Lower Bucks-
921 AM EST Wed Dec 13 2017

This Hazardous Weather Outlook is for central Delaware, northern
Delaware, southern Delaware, northeast Maryland, central New
Jersey, southern New Jersey and southeast Pennsylvania.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ430-431-454-455-141500-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
921 AM EST Wed Dec 13 2017

...GALE WARNING IN EFFECT UNTIL 6 PM EST THIS EVENING...

This Hazardous Weather Outlook is for Atlantic coastal waters and
Delaware Bay Waters.

.DAY ONE...Today and Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Gale Warning.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ450>453-141500-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
921 AM EST Wed Dec 13 2017

...GALE WARNING IN EFFECT UNTIL MIDNIGHT EST TONIGHT...

This Hazardous Weather Outlook is for Atlantic coastal waters.

.DAY ONE...Today and Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Gale Warning.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Local storm report, Dec 13, 11:09 AM EST, 4 hours 19 minutes before
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1109 AM EST WED DEC 13 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     SNOW             MOUNT POCONO            41.12N  75.36W
12/13/2017  M0.3 INCH        MONROE             PA   TRAINED SPOTTER

            OVERNIGHT

&&

EVENT NUMBER PHI1701934

PO
Special weather statement, Dec 13, 2:57 PM EST, 31 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
257 PM EST Wed Dec 13 2017

DEZ001-NJZ015>019-PAZ070-071-106-140300-
New Castle-Mercer-Salem-Gloucester-Camden-Northwestern Burlington-
Delaware-Philadelphia-Lower Bucks-
Including the cities of Wilmington, Trenton, Pennsville,
Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Media,
Philadelphia, Morrisville, and Doylestown
257 PM EST Wed Dec 13 2017

...LOW WATER LEVELS ON THE TIDAL DELAWARE RIVER THROUGH THIS
EVENING...

A strong west to northwest wind resulted in low water levels on
the tidal Delaware River today. The low water levels may cause
navigation problems around the time of low tide into this evening
on the tidal Delaware River and on some of its tidal tributaries.
Water levels are expected to drop to around or just below 2.0
feet below Mean Lower Low Water.

Low tide at Philadelphia takes place at 4:32 PM. Low tide at
Trenton occurs at 6:04 PM. Low tide occurred at Reedy Point at
2:01 PM.

The west to northwest wind will diminish this evening, and water
levels should gradually return to more typical readings
thereafter.

MPS

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 12, 9:37 PM ESTWind AdvisoryPHIAtlantic, Cape May, Cumberland12 hr
Dec 13, 6:05 PM ESTSmall Craft AdvisoryPHI33 hr

Nearby

Winter Weather Advisories in New Jersey, 2017Winter Weather Advisories in Pennsylvania, 2017Every winter weather advisory in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.