textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated key messages.

KEY MESSAGES

1. Low pressure slowly pulls away today, resulting in lingering unsettled weather.

2. A stretch of below normal temperatures begins today, continuing through the weekend as a much colder airmass moves overhead.

3. Widespread minor and localized moderate tidal flooding expected along the New Jersey coast today.

DISCUSSION

KEY MESSAGE 1...Low pressure slowly pulls away today, resulting in lingering unsettled weather.

A vigorous upper-level trough continues to evolve across the Eastern U.S. today. This supported the surface low deepening near our CWA, which will head NE across the waters off New England today. Overall, it will be unsettled across our region today.

Not much has changed with regards to the cold air following the system and the subsequent change in p-type for NW areas. The strength of the parent upper-level trough results in a colder air mass moving in with time, however the initial air mass is not all that cold (the lack of a cold antecedent air mass). As the surface low is consolidating off the northern Mid-Atlantic coast, the winds are turning more out of the northwest and this will increase the cold air advection. This will result in some colder air seeping southeastward today and tonight. The air mass may become sufficiently cold enough mostly across our far northwestern zones for some snow across the higher elevations, confined mainly to the Pocono Plateau. Wouldn't be shocked if some higher elevations got 1-2 inches, but overall less than an inch is expected. Some locations NW of I-95, especially higher elevations, may see a few wet flakes mixing in, especially as precip winds down late today and tonight, but no accumulations are expected. Otherwise, a rain event is forecast. Additional rainfall through tonight looks to be maximized along a band from near Allentown southeast into central NJ, where a half inch or more may yet fall. Amounts look to quickly diminish toward the southwest, with little if any additional rain across northeastern Maryland and much of Delaware.

KEY MESSAGE 2...A stretch of below normal temperatures begins today, continuing through the weekend as a much colder airmass moves overhead.

In the wake of the storm, as it deepens and tracks toward the Canadian Maritimes over the weekend, a colder air mass will be in place across our area. In addition, a tightened pressure gradient coupled with deeper mixing will result in a period of breezy to windy conditions over the weekend. The strongest winds look to occur on Saturday, with peak gusts to about 30 mph, then while still gusty on Sunday it appears the speeds come down a little. Daytime temperatures today and Saturday should not get out of the 40s for many areas, with temperatures at night dropping into the 20s to 30s. There could even be some lake effect snow and/or rain showers into the southern Poconos on Saturday.

Temperatures start to moderate a bit Sunday through Tuesday. Despite that, high temperatures are only in the upper 40s to low 50s each day which is still below average for this time of year.

While we are likely to get our first freeze sometime during this stretch, the Frost/Freeze program area-wide ends on Sunday November 15th. Beyond that, no further frost/freeze headlines will be issued.

KEY MESSAGE 3...Widespread minor and localized moderate tidal flooding expected along the New Jersey coast today.

Strong easterly flow with a deepening area of low pressure resulted in a push of water towards the New Jersey coast. Winds have turned more northerly, though the direction overall will not be west enough to drain the water quickly. As a result, widespread minor tidal flooding is expected with this morning's high tide along the Raritan Bay and New Jersey shore. A Coastal Flood Advisory was issued. Higher water levels look possible along Ocean County and its back bays, so this area has been upgraded to a Coastal Flood Warning.

Flow has turned more westerly around Delaware Bay, southern Delaware, and Chesapeake Bay. As a result, only spotty minor tidal flooding at most is expected.

Tidal issues are anticipated to diminish after this morning's high tide.

AVIATION /08Z FRIDAY THROUGH TUESDAY/

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

Thru 12Z this morning...Most terminals are MVFR to start but degradation to IFR is expected at all sites shortly as stratus lowers. Winds generally out of the north/northwest around 10 kt. Moderate confidence.

Today...IFR/LIFR conditions expected with periods of rain, low clouds, and fog persisting. Winds out of the northwest around 10-15 kt with gusts 20-25 kt. Moderate confidence.

Tonight...IFR/LIFR conditions to start but conditions gradually improve as drier air moves in. Expecting VFR after 06z at most sites. Northwest winds around 10 kt. Moderate confidence.

Outlook...

Saturday and Sunday...Mainly VFR. Northwest wind gusts 20-30 knots.

Monday...VFR. No significant weather.

MARINE

Low pressure is moving offshore currently. For today, winds turn more north/northwesterly increasing to around 20-30 kt and gusts over the ocean waters up to 40 kts with seas 5 to 7 feet. Upgraded ocean zones to Gales, kept Small Craft Advisory on Delaware Bay. Once the Gale Warning expires for the near shore zones, an SCA will be needed. Outlook...

Saturday...Small Craft Advisory conditions probable. Near gale force wind gusts possible.

Sunday...Small Craft Advisory conditions possible.

Monday...Marine conditions will be below advisory criteria.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...Coastal Flood Advisory from 9 AM this morning to 3 PM EST this afternoon for NJZ012>014-022>025-027. Coastal Flood Warning from 9 AM this morning to 3 PM EST this afternoon for NJZ020-026. DE...None. MD...None. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ430- 431. Gale Warning until 6 PM EST this evening for ANZ450-480. Small Craft Advisory until 6 AM EST early this morning for ANZ451>455. Gale Warning until 6 PM EST this evening for ANZ451>455- 481>483-485.