textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated aviation section.

KEY MESSAGES

1...A warming trend will prevail through mid-week as a warm front lifts northward across the region, though clouds and spotty showers will accompany the front.

2. A Cold Front comes through on Wednesday Night, bringing some showers and thunderstorms in the afternoon and evening ahead of the front.

3. While temperatures fall in the wake of the front on Thursday, things have trended warmer as Wednesday Night's cold front stalls over our area or lifts north as a warm front. Still looks unsettled through the end of the week though.

DISCUSSION

KEY MESSAGE 1...A warming trend will prevail through mid-week as a warm front lifts northward across the region, though clouds and spotty showers will accompany the front.

High pressure has slid off the east coast and will remain to our southeast through mid-week. Meanwhile, a warm front will start lifting northward across the region today through early Tuesday. This front will bring increased cloud cover today through Tuesday, along with some spotty showers potentially arriving later today and lingering into Tuesday. There may even be a rumble of thunder as the system pushes northward across the region later tonight, but overall, impacts look minimal, with little if any severe risk and only modest amounts of rain, perhaps a couple tenths of a inch. The other main impact will be the aforementioned increasing warmth. Today's highs should be mostly in the 60s, with a few spots possibly reaching 70, except of course colder near the ocean (a theme which will prevail through the forecast because, after all, its early Spring still). Lows tonight will mostly stay in the 50s, with highs on Tuesday rising well into the 70s to near 80. Lows Tuesday night appear likely to stay in the muggy 60s, with highs into the 80s for most on Wednesday. This may challenge records, so see the climate section below.

KEY MESSAGE 2...A Cold Front comes through on Wednesday Night, bringing some showers and thunderstorms in the afternoon and evening ahead of the front.

A warm and humid day on Wednesday (perhaps with some record highs) is expected. However, some showers and thunderstorms are anticipated ahead of a cold front, mainly later in the day and into the overnight hours. While we cannot rule out some strong to severe thunderstorms, the threat is overall low as model soundings show some instability but not overwhelming. Shear is also relatively weak. Will have to continue to monitor how things trend and once we get within range of CAM guidance, but SPC currently does not have any area outlooked in the Day 3 Severe Weather Outlook.

Still expecting some rain though, mainly in the mid to late afternoon/early evening, continuing into the overnight hours. Current QPF is anywhere from a tenth to half an inch of rain, with the highest amounts north and west of the I-95 corridor. No flooding concerns expected.

KEY MESSAGE 3... While temperatures fall in the wake of the front on Thursday, things have trended warmer as Wednesday Night's cold front stalls over our area or lifts north as a warm front. Still looks unsettled through the end of the week though.

The cold front will stall over our area and remain as a stalled boundary or lift north as a warm front. The main change with this forecast package was having warmer temperatures for the end of the week and into the weekend. Yesterday, it was looking like temperatures Friday-Saturday would be in the 50s. However, with the front now failing to clear the area, it could lift north as a warm front, ushering in a warmer airmass. Temperatures on Thursday will only fall into the mid to upper 60s or low 70s, but ramp back up to widespread 70s Friday through Sunday. Cannot say there is high confidence in this occurring as some guidance has the front stalling over the area, which would keep temperatures cooler with more cloud cover and showers over the area.

However, the unsettled pattern likely will continue into the weekend until a sweeping strong cold front comes through Sunday or Sunday Night. Thursday through Sunday won't be a washout any day, but each day features PoPs. However, the threat for any severe weather or flooding is low to none Thursday through Saturday Night.

AVIATION /12Z MONDAY THROUGH FRIDAY/

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

Today...VFR. Low-level wind shear ends early. Southwesterly winds increase to 10 to 15 with gusts up to around 20 kt. Could be a stray shower around in the afternoon but kept VCSH out of the TAFs for now. High confidence.

Tonight...Primarily VFR. Sub-VFR conditions are possible at times in any scattered showers, with a slight chance of a thunderstorm late tonight. Added in VCSH, but keeping TS out of the TAFs for now. Winds SSW 5-10 kts. Southwesterly low-level wind shear expected to return tonight.

Tuesday...Primarily VFR. Sub-VFR conditions are possible at times in any scattered showers. Winds SSW 10-15 kts with gusts to 20 kts.

Outlook...

Tuesday Night through Wednesday Morning...VFR. No significant weather.

Wednesday Afternoon through Wednesday Night...Sub-VFR conditions likely (70-80%) with widespread showers and scattered thunderstorms moving through. Wind gusts out of the southwest around 20 kt.

Thursday through Friday...Sub-VFR conditions possible (50-60%) with low clouds and scattered showers around with a stalled boundary nearby.

MARINE

A Small Craft Advisory is in effect for the ocean waters through Tuesday. Winds will generally be S to SSW at 10-20 kts with occasional gusts to 25 kts, with seas of 4-5 feet today building to 5-7 feet Tuesday. No headlines for the Delaware Bay where gusts should mostly stay below 25 kts thru Tuesday.

Outlook...

Tuesday Night through Wednesday...A Small Craft Advisory is in place for all ocean zones. Wind gusts out of the southwest will be around 25 kt with seas 5 to 7 feet. No marine headlines on Delaware Bay as wind gusts are currently projected to be below 25 kt.

Wednesday Night...SCA conditions possible (40-50%) as winds diminish but seas could linger near 5 feet.

Thursday through Friday...SCA conditions possible (40-50%) as seas hover near 5 feet and wind gusts could get to 25 kt at times out of the east/southeast.

CLIMATE

The warmth is forecast to surge into our area during the first half of this week, with it peaking on Wednesday. Given the current forecast, some inland areas could challenge their record high temperatures on Wednesday, April 1st.

Location Record High 4/1 -------- --------------- ACY Atlantic City, NJ80/1978 PHL Philadelphia, PA81/1978 ILG Wilmington, DE 81/1978 ABE Allentown, PA84/1978 TTN Trenton, NJ81/1986 RDG Reading, PA82/1917 GED Georgetown, DE80/1979 MPO Mount Pocono, PA81/1998 55N AC Marina, NJ72/1955

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 6 PM EDT Wednesday for ANZ450>455.