textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated wording for Key Point 1. Aviation and Marine sections updated.

KEY MESSAGES

1. The remnants of Isaias will continue to move away through this evening.

2. Widespread minor tidal flooding expected Monday morning for much of the Atlantic Ocean coasts in New Jersey and Delaware.

3. Increasing temperatures and humid conditions through midweek with some shower chances. The pattern becomes more active towards the end of the week and into the start of the weekend. By the weekend, temperatures get much cooler.

DISCUSSION

KEY MESSAGE 1...The remnants of Isaias will continue to move away through this evening.

The remnant low of what was Hurricane Isaias is well offshore now and will continue to move away from our region. High pressure aloft and at the surface will build in through the middle of the week. Increasing amounts of sunshine today and some gusty winds will be around for the afternoon.

KEY MESSAGE 2...Widespread minor tidal flooding expected Monday morning for much of the Atlantic Ocean coasts in New Jersey and Delaware.

While we will be moving away from the New Moon, and winds will begin to turn with the passage of the remnant low, tidal levels will remain elevated Monday morning as winds will remain shore parallel in many locations. This will trap water along the coast, and particularly in the back bays, resulting in a round of widespread minor tidal flooding across most of the Atlantic Ocean coast in New Jersey and Delaware as well as along the Delaware Bay shore in Kent County, Delaware.

Spotty minor tidal flooding is also possible Monday morning along the remainder of the Delaware Bay coasts, the tidal Delaware River, the Raritan Bay coast, and the Atlantic Ocean coast in Monmouth County.

No tidal flooding concerns expected along the Chesapeake Bay.

KEY MESSAGE 3...Increasing temperatures and humid conditions through midweek with some shower chances. The pattern becomes more active towards the end of the week and into the start of the weekend. By the weekend, temperatures get much cooler.

An expansive mid and upper-level ridge well to our south will keep the flow more zonal through much of this coming week. There will be multiple pieces of upper-level energy moving through the region along with a cold front leading to some shower chances this week. A cold front sinks south into the area Tuesday night and into Wednesday as a mid-level shortwave also moves through the region. This may lead to some isolated showers Tuesday evening into Tuesday night. However, any precipitation currently looks limited. The cold front may not fully clear our area until later in the day Wednesday. Additional isolated showers are possible Wednesday evening into Wednesday night as more upper-level energy moves through the region. By Thursday, it is drier as high pressure builds in. In terms of temperatures, on Tuesday highs reach the 70s for many with humid conditions. On Wednesday, highs mainly reach the mid 70s to mid 80s with humid conditions continuing. Behind the cold front, highs on Thursday are in the 60s for most with lower humidity values.

By Thursday night, the upper-level pattern begins to become more amplified. An upper-level trough approaches the region from the west for the end of the week and moves into the Northeast this weekend. There is a large amount of variation among model guidance given this being towards the end of the long term period. As of right now, at the surface, a deepening low pressure system in Canada will continue to move eastward as it strengthens. This low pressure system currently looks to bring rain to the area during the time period of Thursday night through Friday night. A strong cold front looks to move through sometime Friday leading to much cooler conditions this weekend. Right now, highs on Friday are mainly in the upper 60s to mid 70s. Over the weekend, forecast highs are mainly in the 50s. It will also be a windy period due to the deepening low to the north and an expansive high building in from the west leading to a tight pressure gradient across the region.

AVIATION /14Z MONDAY THROUGH FRIDAY/

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

This afternoon...A continuation of improving conditions at the remaining terminals to VFR by 15-17Z. N winds 10 to 15 kt with gusts up to 20 kt. Winds back to the NW at 10 kt or less late. Moderate confidence.

Monday night...VFR. Light and variable winds. No significant weather. High confidence.

Outlook...

Tuesday through Thursday...VFR. No significant weather.

Thursday night through Friday...Sub-VFR possible with rain showers. Gusty southwest to west winds on Friday.

MARINE

SCA conditions continue today with decreasing clouds. Seas remain elevated around 5-7 feet but will subside to 3-4 feet Monday night. Winds will be from the North around 15-20 kts with gusts up to 25 kts before subsiding later in the afternoon and becoming NNW around 10 kts.

Outlook...

Tuesday through Thursday...No marine hazards expected.

Friday...SCA conditions probable with Gales possible. Increasing southwest winds of 25-30 kts and seas building to 5-7 feet.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...Coastal Flood Advisory until 2 PM EDT this afternoon for NJZ020-022>027. DE...Coastal Flood Advisory until 2 PM EDT this afternoon for DEZ002>004. MD...None. MARINE...Small Craft Advisory until 4 AM EDT Tuesday for ANZ450>452. Small Craft Advisory until 2 AM EDT Tuesday for ANZ453>455.