textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

The Wind Advisory for Carbon and Monroe Counties in PA has been cancelled.

KEY MESSAGES

1. Gusty winds behind a dry cold front expected Today.

2. A weak cold front is expected on Monday.

3. A coastal low could lead to unsettled weather during the Wednesday through Friday time period.

DISCUSSION

KEY MESSAGE 1...Gusty winds behind a dry cold front expected Today.

The cold front is now clear of the region and continues to progress southward.

Wind gusts out of the north/northwest will continue through much of this afternoon. Gusts of 30-35 mph are anticipated. However, with winds decreasing across the Poconos, have cancelled the Wind Advisory for Carbon and Monroe Counties in PA. Winds will gradually diminish mid- afternoon into the early evening.

Outside of gusty winds, the weather this weekend shouldn't be impactful with dry weather and temperatures a few degrees below normal, but still pleasant as we get towards meteorological summer.

KEY MESSAGE 2...A weak cold front is expected on Monday.

In general, upper-level troughing will remain in place over much of the Northeastern US through early next week. At the surface, a weak cold front is expected to pass through the region on Monday.

The first chance for showers and perhaps a storm or two will be on Monday with the passage of the weak front. Chances will be greatest across the eastern half or so of the area, currently ranging from 20- 40%. No significant impacts are expected.

Temperatures through Wednesday look to be fairly close to seasonal norms across the area, with highs generally in the mid 70s and lows in the mid 50s.

KEY MESSAGE 3...A coastal low could lead to unsettled weather during the Wednesday through Friday time period.

By mid-week, an upper- low is expected to begin to close off, before tracking slowly northeastward away from the coast. A surface low will likely form in association with the closed upper-low off the coast as it pulls away.

There remain discrepancies in guidance as to how close to the coast the low will get due in part to strong high pressure building in from the northwest. A more progressive low lifting to the northwest will likely result in fewer impacts. A slower moving or even stalled coastal low could result in breezier conditions. While models generally continued on their previous trends (most depicting the more progressive solution, while the GFS appears to be the slow outlier), there was a general trend to drier conditions through this period. At most now, there is a 20% chance of showers primarily on Wednesday.

High pressure and warmer conditions should build in to the region after the low late next week.

AVIATION /15Z SATURDAY THROUGH WEDNESDAY/

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

Today...Prevailing VFR. A deck of low clouds has progressed further south than previously expected, so KABE may see brief MVFR ceilings over the next few hours, but expect its progress to slow or stall before it reaches any of the other TAF sites. The front is south of all of the TAF sites now, resulting in prevailing northwesterly winds. Peak wind gusts between 25 to 30 kt are expected through about 18Z. Winds are expected to shift to northerly after 18Z and gradually diminish. For KPHL, KTTN, KPNE, KILG, KMIV, and KACY, winds could shift to north northeasterly by 21Z. High confidence.

Tonight...VFR conditions expected. Wind speeds should diminish to less than 10kt by or shortly after 00Z. For the coastal plains, especially KMIV and KACY, wind direction could be variable overnight, but for the most part, expect the prevailing wind direction to be northwesterly.

Outlook...

Sunday...VFR. No significant weather.

Monday through Wednesday...Primarily VFR. There will be a slight chance of a few periods of sub-VFR conditions each day with a few rain showers and perhaps a thunderstorm.

MARINE

A Small Craft Advisory remains in effect for all marine zones as a cold front comes through. This will result in north/northwesterly winds around 20 to 30 kt through at least mid day today. Seas will also increase, getting into the 3 to 6 foot range.

The Small Craft Advisory expires by late this afternoon for Delaware Bay, but will continue into the first half of Tonight for all ocean zones, primarily for elevated seas.

Outlook...

Sunday through Monday night...Winds and seas should stay below SCA criteria.

Tuesday through Wednesday...There is a chance for SCA conditions primarily due to elevated seas.

Rip Currents...

We are forecasting a MODERATE risk for the formation of dangerous rip currents today and tomorrow.

For today, although winds will be blowing off shore, it will lead to breaking waves around 2-3 feet in the surf zone. Although the dominant period is wind driven waves at 5 to 6 seconds, there is an underlying longer period around 8 to 9 seconds. Although nwps rip risk suggests that the direction of the flow should keep the risk lower, local research and a legacy rip risk calculator suggest this is a moderate risk.

For Sunday, northwest winds in the morning will become southerly in the afternoon around 15 mph. Although breaking waves heights should be a little lower, around 1-3 feet in the surf zone, the wind direction shift, and the potential for stronger winds in the afternoon mean that there will be another moderate risk for rip currents tomorrow.

Ocean water temperatures are in the 50s to low 60s. These chilly water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water.

For specific beach forecasts, visit weather.gov/beach/phi

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ430- 431. Small Craft Advisory until 2 AM EDT Sunday for ANZ450>452. Small Craft Advisory until 11 PM EDT this evening for ANZ453>455.