Alert archive / Pennsylvania / Winter Storm Warnings in 2018

Winter Storm Warning 4, NWS Philadelphia/Mount Holly

February 17, 20187 counties in Pennsylvania; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this winter storm warning at Feb 17, 2018, 7:41 PM EST for 7 counties in Pennsylvania; 5 counties in New Jersey. It was in force for 4 hr. 34 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Feb 17, 2018, 7:41 PM EST (00:41 UTC)
Expired
Feb 18, 2018, 12:05 AM EST
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 00:40 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.

What was reported inside it

TimeReportWhereRemark
Feb 17, 7:58 PM ESTSNOW 6Spring Twp, PA
Feb 17, 7:58 PM ESTSNOW 6.3Danielsville, PA
Feb 17, 8:03 PM ESTSNOW 5.4Butler, NJ
Feb 17, 8:04 PM ESTSNOW 6.2Stewartsville, NJ
Feb 17, 8:07 PM ESTSNOW 6.3Bushkill Twp, PA
Feb 17, 8:08 PM ESTSNOW 3Perkasie, PA
Feb 17, 8:09 PM ESTSNOW 1.3Trevose, PA
Feb 17, 8:09 PM ESTSNOW 5.5Green Lane, PA
Feb 17, 8:09 PM ESTSNOW 6.8Laurys Station, PA
Feb 17, 8:11 PM ESTSNOW 4Newton, NJ
Feb 17, 8:11 PM ESTSNOW 6New Tripoli, PA
Feb 17, 8:12 PM ESTSNOW 6.3Allentown, PA
Feb 17, 8:13 PM ESTSNOW 7.1S Allentown, PA
Feb 17, 8:14 PM ESTSNOW 5.7Hellertown, PA
Feb 17, 8:43 PM ESTSNOW 6Douglassville, PA
Feb 17, 8:44 PM ESTSNOW 3Pottstown, PA
Feb 17, 8:44 PM ESTSNOW 8Roxbury Twp, NJ
Feb 17, 8:47 PM ESTSNOW 4Graterford, PA
Feb 17, 8:48 PM ESTSNOW 5.9Upper Nazareth Twp, PA
Feb 17, 8:49 PM ESTSNOW 3.9Readington Twp, NJ
Feb 17, 8:53 PM ESTSNOW 6.81 Ese Franklin, NJ
Feb 17, 8:54 PM ESTSNOW 7.2Martins Creek, PA
Feb 17, 8:55 PM ESTSNOW 7Rockaway, NJ
Feb 17, 8:56 PM ESTSNOW 5.5Newton, NJ
Feb 17, 8:57 PM ESTSNOW 5.5Columbia, NJ
Feb 17, 8:57 PM ESTSNOW 7Hamburg, PA
Feb 17, 8:59 PM ESTSNOW 2.73 N Wantage, NJ
Feb 17, 9:03 PM ESTSNOW 6.5Hamburg, PA
Feb 17, 9:03 PM ESTSNOW 7.5Walnutport, PA
Feb 17, 9:04 PM ESTSNOW 6.3Emmaus, PA
Feb 17, 9:05 PM ESTSNOW 6Hellertown, PA
Feb 17, 9:07 PM ESTSNOW 7.2Stewartsville, NJ
Feb 17, 9:07 PM ESTSNOW 7.4S Allentown, PA
Feb 17, 9:08 PM ESTSNOW 6.6New Tripoli, PA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.7 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 00:00Z on 2018-02-18Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2018-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 334 square meters per square second.1939587897117136Sfc1 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
620 m above ground
0-6 km bulk shear
106 kt
0-1 km storm-relative helicity
334 m²/s²
0-3 km storm-relative helicity
517 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

999 
WWUS41 KPHI 180041
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
741 PM EST Sat Feb 17 2018


NJZ001-007>010-PAZ054-055-060>062-103-105-180900-
/O.UPG.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
/O.NEW.KPHI.WS.W.0004.180218T0041Z-180218T0900Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Carbon-Monroe-Berks-
Lehigh-Northampton-Western Montgomery-Upper Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, Jim Thorpe, Stroudsburg, Reading, 
Allentown, Bethlehem, Easton, Collegeville, Pottstown, Chalfont, 
and Perkasie
741 PM EST Sat Feb 17 2018

...WINTER STORM WARNING IN EFFECT UNTIL 4 AM EST SUNDAY...

* WHAT...Heavy snow. Total snow accumulations of around 6 inches 
  are expected.

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

* WHEN...Until 4 AM EST Sunday.

* ADDITIONAL DETAILS...Plan on difficult travel conditions. Be
  prepared for significant reductions in visibility at times. The
  snow may fall at 1 to 2 inches per hour at times in parts of the
  region, resulting in rapidly deteriorating road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions will make travel very hazardous or impossible. If you
must travel, keep an extra flashlight, food and water in your
vehicle in case of an emergency. The latest road conditions for
the state you are calling from can be obtained by calling 5 1 1.

&&

$$

NJZ012-015-PAZ101-102-104-106-180900-
/O.CON.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
Middlesex-Mercer-Western Chester-Eastern Chester-
Eastern Montgomery-Lower Bucks-
Including the cities of New Brunswick, Trenton, Honey Brook, 
Oxford, West Chester, Kennett Square, Norristown, Lansdale, 
Morrisville, and Doylestown
741 PM EST Sat Feb 17 2018

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM EST
SUNDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 5 
  inches are expected.

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

* WHEN...Until 4 AM EST Sunday. The heaviest snow is expected 
  through the evening hours.

* ADDITIONAL DETAILS...Plan on difficult travel conditions. Be 
  prepared for reduced visibilities at times. The snow may fall 
  at up to an inch per hour at times in parts of the region, 
  which would result in rapid deteriorating road conditions.

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.

&&

$$

DEZ001-MDZ008-NJZ013-016>019-PAZ070-071-180900-
/O.CON.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
New Castle-Cecil-Western Monmouth-Salem-Gloucester-Camden-
Northwestern Burlington-Delaware-Philadelphia-
Including the cities of Wilmington, Elkton, Freehold, Pennsville,
Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Media, 
and Philadelphia
741 PM EST Sat Feb 17 2018

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM EST
SUNDAY...

* WHAT...Snow expected. Total snow accumulations of around 2 
  inches, with localized amounts up to 4 inches, are expected.

* WHERE...Portions of central and southern New Jersey, southeast 
  Pennsylvania, northeast Maryland and northern Delaware.

* WHEN...Until 4 AM EST Sunday. The heaviest snow is expected 
  through the evening hours.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Be 
  prepared for reduced visibilities at times. A burst of heavy 
  snow this evening would allow for more efficient accumulations 
  and deteriorating road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for wet snow means periods of wet 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
2 follow-up statements
643 
WWUS41 KPHI 180251
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
951 PM EST Sat Feb 17 2018


PAZ060-103-180400-
/O.CAN.KPHI.WS.W.0004.000000T0000Z-180218T0900Z/
Berks-Western Montgomery-
Including the cities of Reading, Collegeville, and Pottstown
951 PM EST Sat Feb 17 2018

...WINTER STORM WARNING IS CANCELLED...

Heavy snow has ended. Light snow or snow showers may continue for
a few more hours.

$$

DEZ001-MDZ008-NJZ016>018-PAZ070-071-101-102-104-180400-
/O.CAN.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
New Castle-Cecil-Salem-Gloucester-Camden-Delaware-Philadelphia-
Western Chester-Eastern Chester-Eastern Montgomery-
Including the cities of Wilmington, Elkton, Pennsville, 
Glassboro, Camden, Cherry Hill, Media, Philadelphia, Honey Brook,
Oxford, West Chester, Kennett Square, Norristown, and Lansdale
951 PM EST Sat Feb 17 2018

...WINTER WEATHER ADVISORY IS CANCELLED...

Heavy snow has ended. Light snow or snow showers may continue for
a few more hours.

$$

NJZ001-007>010-PAZ054-055-061-062-105-180900-
/O.CON.KPHI.WS.W.0004.000000T0000Z-180218T0900Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Carbon-Monroe-Lehigh-
Northampton-Upper Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, Jim Thorpe, Stroudsburg, Allentown, 
Bethlehem, Easton, Chalfont, and Perkasie
951 PM EST Sat Feb 17 2018

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM EST SUNDAY...

* WHAT...Heavy snow. Total snow accumulations of 6 to 8 inches 
  are expected.

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

* WHEN...Until 4 AM EST Sunday. Heavier snow should end by
  midnight. 

* ADDITIONAL DETAILS...Plan on difficult travel conditions. Be 
  prepared for significant reductions in visibility at times. 
  The snow may fall at 1 to 2 inches per hour at times in parts 
  of the region, resulting in rapidly deteriorating road 
  conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions will make travel very hazardous or impossible. If you
must travel, keep an extra flashlight, food and water in your
vehicle in case of an emergency. The latest road conditions for
the state you are calling from can be obtained by calling 5 1 1.

&&

$$

NJZ012-015-PAZ106-180900-
/O.CON.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
Middlesex-Mercer-Lower Bucks-
Including the cities of New Brunswick, Trenton, Morrisville, 
and Doylestown
951 PM EST Sat Feb 17 2018

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM EST
SUNDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 5 
  inches are expected.

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

* WHEN...Until 4 AM EST Sunday. The heaviest snow is expected 
  through the late evening hours.

* ADDITIONAL DETAILS...Plan on difficult travel conditions. Be 
  prepared for reduced visibilities at times. The snow may fall 
  at up to an inch per hour at times in parts of the region, 
  which would result in rapid deteriorating road conditions.

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.

&&

$$

NJZ013-019-180900-
/O.CON.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
Western Monmouth-Northwestern Burlington-
Including the cities of Freehold, Moorestown, and Mount Holly
951 PM EST Sat Feb 17 2018

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM EST
SUNDAY...

* WHAT...Snow expected. Total snow accumulations of around 2
  inches are expected.

* WHERE...Portions of central and southern New Jersey, southeast 
  Pennsylvania, northeast Maryland and northern Delaware.

* WHEN...Until 4 AM EST Sunday. The heaviest snow is expected 
  through the late evening hours.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Be 
  prepared for reduced visibilities at times. A burst of heavy 
  snow this evening would allow for more efficient accumulations 
  and deteriorating road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for wet snow means periods of wet 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
863 
WWUS41 KPHI 180505
WSWPHI

URGENT - WINTER WEATHER MESSAGE
National Weather Service Mount Holly NJ
1205 AM EST Sun Feb 18 2018

NJZ001-007>010-PAZ054-055-061-062-105-180615-
/O.CAN.KPHI.WS.W.0004.000000T0000Z-180218T0900Z/
Sussex-Warren-Morris-Hunterdon-Somerset-Carbon-Monroe-Lehigh-
Northampton-Upper Bucks-
Including the cities of Newton, Washington, Morristown, 
Flemington, Somerville, Jim Thorpe, Stroudsburg, Allentown, 
Bethlehem, Easton, Chalfont, and Perkasie
1205 AM EST Sun Feb 18 2018

...WINTER STORM WARNING IS CANCELLED...

Some light snow showers may persist for a couple more hours,
however the accumulating snow has ended. While the warning has
been cancelled, still use caution while traveling tonight as 
untreated surfaces can be slippery.

$$

NJZ012-013-015-019-PAZ106-180615-
/O.CAN.KPHI.WW.Y.0008.000000T0000Z-180218T0900Z/
Middlesex-Western Monmouth-Mercer-Northwestern Burlington-
Lower Bucks-
Including the cities of New Brunswick, Freehold, Trenton, 
Moorestown, Mount Holly, Morrisville, and Doylestown
1205 AM EST Sun Feb 18 2018

...WINTER WEATHER ADVISORY IS CANCELLED...

While the advisory has been cancelled, use caution while 
traveling tonight as untreated surfaces can still be slippery.

$$

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

Nearby

Winter Storm Warnings in Pennsylvania, 2018Winter Storm Warnings in New Jersey, 2018Every winter storm warning in 2018

Sources

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