Weather briefing WFO PHI – 2015-02-28 330 PMEmergency Managers and other Key Partners,
A briefing package has been issued for the accumulating snowfall and ice we are expecting Sunday morning through Monday morning. The briefing package is attached.
This will be the only briefing package for this upcoming event.
The Executive Summary is as follows:
• Winter Weather Advisory in effect for Eastern Pennsylvania, New Jersey, Delaware, and Eastern Maryland from 10 AM Sunday to 4 AM Monday.
• Snow will overspread the region from west to east, beginning in Eastern Pennsylvania late Sunday Morning, and reaching the New Jersey and Delaware Coastline by early Sunday Afternoon. Well to the north and west of I-95, snow is expected to become moderate at times, particularly late in the afternoon and evening when snowfall rates up to one inch per hour are possible. In addition to slippery roads, this will reduce visibility, and further exacerbate hazardous travel conditions.
• The heaviest snowfall is expected in the vicinity of the I-78 corridor and points to the north, and will be plowable, with storm total snowfall of 3 to 6 inches. Precipitation in this area will remain predominantly snow, although some very light sleet and freezing rain may mix in late Sunday evening.
• Further to the south between I-78 and I-95, 1 to 3 inches of snow is expected before the changeover to freezing rain by early evening. Although snowfall amounts will be less along the I-95 corridor, this is where the greatest amount of ice from freezing rain will occur, with storm total ice of 0.1 to 0.25” expected.
• For South Coastal New Jersey and Southern Delaware, snow will changeover to sleet and freezing rain sooner, with storm total snowfall of one inch or less and storm total ice of around one-tenth of an inch.
• Precipitation is expected to end from west to east late Sunday Night, prior to the morning rush hour on Monday.
• During the day on Monday, temperatures will warm above freezing, before falling back into the teens and single numbers Monday Night and Tuesday Morning. This will cause any remaining water on roads, sidewalks, driveways, parking lots, and other untreated surfaces to refreeze during this time frame.
…SNOW TO IMPACT THE THURSDAY MORNING COMMUTE…
…WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO
1 PM EST THURSDAY…
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW WHICH IS IN EFFECT FROM 10 PM THIS
EVENING TO 1 PM EST THURSDAY.
* ACCUMULATIONS…SNOW ACCUMULATION 1 TO 3 INCHES WITH LOCALLY
HIGHER AMOUNTS IN THE LOWER MARYLAND EASTERN SHORE.
* HAZARD TYPES…SNOW.
* TIMING…SNOW DEVELOPS LATE TONIGHT BEFORE TAPERING OFF LATE
* IMPACTS…ROADS WILL LIKELY BE SNOW COVERED AND SLIPPERY DURING
THE THURSDAY MORNING COMMUTE.
* WINDS…NORTH TO NORTHEAST AT 10 TO 15 MPH WITH GUSTS UP TO 25
* TEMPERATURES…MAINLY IN THE LOWER TO MID 20S WHILE ITS
A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW WILL CAUSE
TRAVEL DIFFICULTIES. BE PREPARED FOR SLIPPERY ROADS AND LIMITED
VISIBILITIES…AND USE CAUTION WHILE DRIVING. GIVE YOURSELF
WED FEB 25 2015
A PERIOD OF ACCUMULATING SNOW IS POSSIBLE THURSDAY MORNING WHICH
MAY CAUSE HAZARDOUS TRAVEL CONDITIONS.
PERIODS OF SNOW OR WINTRY PRECIPITATION ARE POSSIBLE SUNDAY
AFTERNOON INTO MONDAY MORNING.
Emergency Managers and other key partners,
Attached is a briefing package for the winter weather event expected this weekend. The Executive Summary is as follows:
• Very cold temperatures are expected again tonight, with lows ranging from 5 degrees below zero in the Poconos and northwest New Jersey to around 5 degrees elsewhere. However, there won’t be much wind, so it won’t feel quite as bad as last night.
• Then another storm will approach from the west on Saturday. Very cold temperatures in the morning will slowly warm through the day, but precipitation is expected to begin as snow Saturday afternoon across our entire County Warning Area (CWA). Then, as warmer air moves north, snow will change briefly to sleet, then rain, from south to north. By evening, rain or rain/snow/sleet mixture is expected in Philadelphia and points south, but with so much entrenched cold air, the transition will take longer further north. For instance, the Lehigh Valley and central New Jersey may not transition to rain until Sunday morning. Please see attached maps for snowfall forecasts.
• Where rain makes contact with very cold surfaces, ice buildup could occur. However, right now we don’t see this as a widespread problem.
• Precipitation will end from west to east on Sunday as another arctic cold front moves in, bringing below normal temperatures to the region for the beginning of the new week.
• Northwest winds will bring low-water conditions on the ocean front, as well as both the Chesapeake and Delaware Bays (including tidal Delaware River), at the time of low tide tonight, and perhaps again at the time of low tide on Saturday.
Bitter cold tonight through Friday night will be followed by another storm Saturday into Sunday. Temperatures on Saturday are expected to rise
through the day and night, changing snow to rain, so accumulations will be tempered. A briefing package is attached. The Executive Summary is
• Record breaking cold will continue over the area into Saturday. Tonight and Friday will be the coldest, with overnight lows 10 to 15 degrees below zero in the far north, and only in the single digits in the south. Winds in the 15 to 25 mph range will drop Wind Chill values down to the minus 25 to minus 35 degree range in the southern Poconos and northwest New Jersey, and in the minus 10 to minus 25 degree range in most other places. Wind Chill Warnings and Advisories have been posted. Friday night will be cold too, but not quite so bitter, and with less winds, it won’t feel quite so bad.
• Another storm is expected to affect the region Saturday into Sunday. Temperatures will be warming on Saturday, but not before snow starts from west to east late Saturday morning or early afternoon. Then precipitation will change from snow to rain from south to north later Saturday afternoon and evening. By Saturday night, precipitation should be all rain south and east of the I-95 corridor. This transition will take longer north and west of Philadelphia, but by Sunday morning, all rain is expected in these areas too. The transition to all rain may take until Sunday morning in the southern Poconos and northwest New Jersey. During the transition from snow to rain, there could be some sleet and a brief period of freezing rain, but ice is not expected to be a major problem with this event.