Alert archive / Pennsylvania / Winter Weather Advisories in 2012

Winter Weather Advisory 7, NWS Philadelphia/Mount Holly

December 20, 2012Carbon County, Monroe County, Pennsylvania

NWS Philadelphia/Mount Holly issued this winter weather advisory at Dec 20, 2012, 9:00 PM EST for Carbon County, Monroe County, Pennsylvania. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Dec 20, 2012, 9:00 PM EST (02:00 UTC)
Expired
Dec 20, 2012, 11:00 PM EST
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly

Counties Carbon County, PA, Monroe County, PA

The radar

The Binghamton radar (KBGM), 140 km from the middle of the area, began a volume at 02:03 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 00:00Z, 2.0 hours before the alert went out and 224 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 2012-12-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 joules per kilogram.LCLEL10008507005003002001001 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 2012-12-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 square meters per square second.1939587897Sfc1 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
3 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
671 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

369 
WWUS41 KPHI 210200
WSWPHI

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
900 PM EST THU DEC 20 2012

PAZ054-055-210400-
/O.CAN.KPHI.ZR.Y.0005.000000T0000Z-121221T0400Z/
/O.NEW.KPHI.WW.Y.0007.121221T0200Z-121221T0400Z/
CARBON-MONROE-
INCLUDING THE CITIES OF...JIM THORPE...STROUDSBURG
900 PM EST THU DEC 20 2012

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 PM EST THIS
EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WINTER
WEATHER ADVISORY FOR SPOTTY FREEZING RAIN CHANGING OVER TO ALL SNOW...WHICH
IS IN EFFECT UNTIL 11 PM EST THIS EVENING. 

* ACCUMULATIONS...SNOW ACCUMULATION OF UP TO 1 INCH...ALONG WITH 
  AROUND A TRACE OF ICE.

* LOCATIONS...HIGHER ELEVATIONS IN CARBON AND MONROE COUNTIES... 
  MAINLY ABOVE 1200 FEET.

* HAZARD TYPES...LIGHT FREEZING RAIN CHANGING OVER TO ALL SNOW SHORTLY.

* ICE ACCUMULATIONS...AROUND A TRACE.

* SNOW ACCUMULATIONS...UP TO 1 INCH.

* TIMING...FOR THE NEXT COUPLE OF HOURS.

* IMPACTS...A LIGHT COATING OF ICE HAS DEVELOPED ON SOME AREA
  ROADWAYS THIS EVENING. THE LIGHT FREEZING RAIN WILL COME TO AN
  END SHORTLY AND CHANGE OVER TO ALL SNOW WHICH WILL COVER THE
  ROADWAYS AND ANY OTHER UNTREATED SURFACES. VISIBILITIES IN THE
  SNOW WILL BE REDUCED TO LESS THAN 1 MILE.

* WINDS...SOUTHEAST 10 TO 15 MPH.

* TEMPERATURES...IN THE LOW TO MID 30S.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR
FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

HEAVENER
1 follow-up statement
153 
WWUS41 KPHI 210404
WSWPHI

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1104 PM EST THU DEC 20 2012

PAZ054-055-210515-
/O.EXP.KPHI.WW.Y.0007.000000T0000Z-121221T0400Z/
CARBON-MONROE-
INCLUDING THE CITIES OF...JIM THORPE...STROUDSBURG
1104 PM EST THU DEC 20 2012

...WINTER WEATHER ADVISORY HAS EXPIRED...

TEMPERATURES ACROSS THE REGION HAVE RISEN ABOVE FREEZING AND WILL
REMAIN SO FOR THE REST OF TONIGHT. SNOW HAS CHANGED OVER TO RAIN.
THEREFORE THE WINTER WEATHER HAS BEEN ALLOWED TO EXPIRE.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 20, 9:11 PM ESTWind AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia12 hr
Dec 21, 12:27 AM ESTCoastal Flood WarningPHIDelaware, Philadelphia11 hr
Dec 21, 4:44 AM ESTAreal Flood WarningPHIChester, Montgomery14 hr
Dec 21, 5:17 AM ESTAreal Flood WarningPHIDelaware4 hr
Dec 21, 5:39 AM ESTAreal Flood WarningPHIBucks10 hr
Dec 21, 7:15 AM ESTRiver Flood WarningPHIDelaware4 hr
Dec 21, 7:36 AM ESTAreal Flood WarningPHIMonroe, Northampton15 hr
Dec 21, 7:49 AM ESTAreal Flood WarningPHIPhiladelphia11 hr
Dec 21, 9:24 AM ESTAreal Flood WarningPHIDelaware4 hr
Dec 21, 9:36 AM ESTRiver Flood WarningPHIBucks10 hr
Dec 21, 12:08 PM ESTRiver Flood WarningPHIChester, Delaware5 hr
Dec 21, 3:16 PM ESTWind AdvisoryPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more27 hr

Nearby

Winter Weather Advisories in Pennsylvania, 2012Every winter weather advisory in 2012

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.