textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

The Coastal Flood Advisories are no longer in effect.

KEY MESSAGES

1. The major winter storm that has been impacting the region is winding down, but cold temperatures and blowing snow will remain in place through Tuesday.

2. Areas of minor tidal flooding may linger with the high tide tonight into early Tuesday.

3. Unsettled weather will impact the region during the middle of the week with light snow Tuesday night and then rain and snow Thursday through Thursday night.

DISCUSSION

KEY MESSAGE 1...The major winter storm that has been impacting the region is winding down, but cold temperatures and blowing snow will remain in place through Tuesday.

A very potent upper trough is now centered just off the Northeast coastline, and is shifting east. Subtle height rises are expected to begin tonight and more rapid height rises are anticipated through the day on Tuesday. At the surface, a potent surface low is located off the New England coast, and will continue to lift northeastward. Weak high pressure will build into the region briefly on during the day Tuesday.

The last of the steady snow has moved offshore and thinning clouds from SW to NE are expected overnight. Temperatures are near or slightly above freezing for most of the area attm with mid 20s for the far N/W areas. Even though the snow is done, breezy conditions are expected to continue well into this evening with gusts 20-30 mph, so patches of blowing snow and reduced visibilities will be possible across the entire area.

With the snowpack in place in addition to cold air advection continuing across the area through tonight, temperatures are expected to fall fairly quickly tonight. The expectation is for temperatures to bottom out the teens northwest of I-95, and in the low 20s southeast. Tuesday looks to feature some sunshine, but it will remain breezy and cold. Winds could gust as high as 30 mph across the area, and high temperatures are only expected to rise into the 20s to low 30s.

KEY MESSAGE 2...Areas of minor tidal flooding may linger with the high tide tonight into early Tuesday.

The times of high tide have passed, and water levels will continue to subside. Some spotty minor coastal flooding is possible on the back bays of Barnegat Bay in Ocean County, NJ and the Little Assawoman Bay in Sussex County, DE with the high tide cycles later tonight.

The Coastal Flood Advisories are no longer in effect.

KEY MESSAGE 3...Unsettled weather will impact the region during the middle of the week with light snow Tuesday night and then rain and snow Thursday through Thursday night.

A clipper system approaches from the west Tuesday night. Precipitation will mostly be snow throughout the region, but the highest snowfall totals will be across the southern Poconos and far northwest New Jersey. Farther south, QPF amounts will be lighter, so not as much snow will accumulate. In addition, rain should mix with the snow, and eventually change to rain Wednesday morning before ending. Overall, about 1 to 3 inches is possible north and west of the Fall Line, with 3 to 4 inches in the southern Poconos. Less than an inch of snow will accumulate elsewhere. Winter Weather Advisories may be needed for the southern Poconos.

As this system lifts to the northeast, winds take on a southwest flow behind this departing system. With warm air advection underway, highs should get into the 40s on Wednesday under clearing skies, allowing for at least some of the snowpack to start melting.

Following that, an upper trough digs into the Midwest, then lower Great Lakes and Ohio Valley. Surface low pressure develops somewhere over the Tennessee Valley on Thursday, then takes a run at the Northeast Thursday night, departing on Friday. Precipitation develops on a warm front extending out from that low on Thursday, and then the bulk of the precipitation falls Thursday night, ending Friday morning. Precipitation may start out as all snow or a rain/snow mix before changing to plain rain south and east of the Fall Line, while precipitation remains as snow to the north and west. A return to a wintry mix is possible Thursday night as the system departs. Uncertain at this time how much snow will accumulate from this system, as there is low confidence with the timing and placement of this system. Temperatures should top off in the 40s once again on Friday.

Highs will get into the 40s to around 50 for the weekend, allowing for further melting of the snowpack over the area.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Rest of tonight (through 12Z)...VFR with decreasing amounts of low clouds. Northwest winds around 10 kt with some lingering gusts near 20 kt. Moderate confidence.

Tuesday...VFR. Northwest winds 10-15 kt with gusts 20-25 kt after 14-16Z. High confidence.

Outlook...

Tuesday night...Sub-VFR in SN.

Wednesday through Wednesday night...Sub-VFR in SN in the morning, changing to RA by midday, then ending. VFR thereafter.

Thursday through Thursday night...Sub-VFR in RA and SN, mostly changing to plain RA by evening, possibly ending as RA and SN late Thursday night.

Friday through Friday night...Sub-VFR possible in RA or SN early in the morning then VFR.

Saturday...VFR.

MARINE

Small Craft Advisories have been issued for the overnight period and into Tuesday for the coastal waters and Delaware Bay. A few Gale gusts may occur into the evening, but the trend for winds is slowly decreasing overnight.

Regarding the river/marine ice, Delaware Bay continues to be mainly ice free outside of shallow near-shore areas. Ice coverage remains around 10-30% from the the Delaware Memorial Bridge up to the Commodore Barry Bridge. North of that up through Philadelphia, ice coverage is around 30-70%.

Outlook...

Tuesday night...SCA conditions developing late. VSBY restrictions in snow and rain.

Wednesday through Wednesday night...SCA conditions. Winds will gust to 25 kt or higher with seas 5 to 6 feet during the day, then sub-SCA conditions Wednesday night. VSBY restrictions, mostly in rain, Wednesday morning.

Thursday through Thursday night...Mostly sub-SCA conditions. VSBY restrictions in snow and rain.

Friday through Friday night...SCA conditions possible, mostly for elevated seas, during the day. Sub-SCA conditions at night. Any VSBY restrictions should end by afternoon.

Saturday...Sub-SCA conditions.

CLIMATE

For Sunday, February 22nd, Trenton and Wilmington experienced daily record snowfall amounts. Trenton's observed snowfall of 7.9" broke the record of 6.3" from 2001. Wilmington's observed snowfall of 5.4" broken the record of 5.0" from 1935.

The daily snowfall records for February 22 and 23 from our climate sites listed below:

February 22 Site Record/Year Allentown (ABE) 8.6"/1948 AC Airport (ACY) 8.0"/2001 Philadelphia (PHL) 7.0"/2001 Reading (RDG) 6.5"/1948 Trenton (TTN) 6.3"/2001 Wilmington (ILG) 5.0"/1935

February 23 Site Record/Year Allentown (ABE) 6.5"/1987 AC Airport (ACY) 6.5"/1987 Philadelphia (PHL) 6.5"/1987 Reading (RDG) 6.5"/1994 Trenton (TTN) 11.4"/1987 Wilmington (ILG) 12.4"/1987

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ430- 431. Small Craft Advisory until 6 PM EST this evening for ANZ450>455.