textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Rainfall amounts for Wednesday and Thursday have decreased.

KEY MESSAGES

1. There is a limited risk for fire weather conditions Tuesday.

2. A few systems bring showers to the area Wednesday into Thursday. Another weak system could bring some showers on Saturday.

DISCUSSION

KEY MESSAGE 1...There is a limited risk for fire weather conditions Tuesday.

The overall breezy pattern that we've been in will persist for Tuesday. SW winds will start to ramp up again by late morning due to diurnal mixing and by afternoon generally expect winds 15 to 20 gusting 25 to 35 mph. The relative humidity Tuesday during peak heating will drop into the 25-35 percent range for many areas. Fuel moisture will decrease Tuesday with significant heating and a gusty breeze, although surface dew points should be higher than Monday. Full green-up has occurred in much of our area however we will continue to coordinate with the State Fire Partners on fuel moisture conditions to determine if a Special Weather Statement is needed for Tuesday.

KEY MESSAGE 2...A few systems bring showers to the area Wednesday into Thursday. Another weak system could bring some showers on Saturday.

An area of low pressure well to the north in Canada will drag a cold front through the Great Lakes and move towards our region on Tuesday Night. Showers begin to move in early Wednesday but the bulk of the rain comes through midday on Wednesday. The front tries to move through but will eventually stall out near or just east of our area. Another area of low pressure will develop over the southeast and lift towards the Mid-Atlantic coast along the stalled front. The trend with the secondary area of low pressure has been a bit further south and east, and think there is a decent chance areas north and west of the I-95 corridor stay dry. Still have PoPs of 50-70% south and east of the I-95 corridor, but PoPs were lowered to slight chance/chance (20-40%) north and west of I-95. Rainfall has trended down a bit which isn't a surprise with the further east track of the second system. Rainfall amounts for most likely end up near a half inch, with at most an inch anticipated. NBM Probabilities for over 1 inch have declined pretty starkly compared to last night. Most areas are now less than 10%, with some isolated pockets of up to 25% over far southeast zones in Delmarva and Southeastern NJ and then the Poconos.

While some guidance still attempted to bring some convective elements to the region, the consensus is that we will see low instability and limited to zero severe/flooding threat. Overall, this will be more beneficial rain for the area with an isolated thunderstorm possible.

For Saturday, a weak area of low pressure will move into the region, potentially producing some showers. This appears to be nothing more than a potential weekend spoiler with no significant impacts expected at this time.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

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

Rest of overnight...VFR. South to SW winds around 5 knots or less and with a modest southwesterly low-level jet moving through expect LLWS. High confidence.

Tuesday...VFR. South to southwest winds 10-20 knots with gusts 25-30 knots, with the strongest winds occurring during the afternoon. Moderate confidence.

Tuesday night...Primarily VFR. Some showers possible north and west of the I-95 terminals. Gusty south/southwest winds gradually diminishing with another period of LLWS possible overnight. Moderate confidence.

Outlook...

Wednesday through Thursday...MVFR/IFR conditions with showers, especially Wednesday midday into the afternoon and then a second round on Thursday daytime. KRDG/KABE may not see any showers on Thursday and things have trended further east away from the I-95 corridor for Thursday as well. If things continue to trend further east, Thursday could have conditions improving to VFR. An isolated thunderstorm possible. Southerly wind gusts 20-25 knots on Wednesday.

Thursday night through Friday Night...VFR. No significant weather.

Saturday...Sub-VFR conditions possible (30-50%) with some showers and potential low clouds moving in.

MARINE

A Small Craft Advisory remains in effect through Tuesday night and beyond for our ocean waters. South to southwest wind gusts will increase up to 30 knots into Tuesday. Seas will also build. For the Delaware Bay, expect a period of Small Craft Advisory conditions Tuesday afternoon through Tuesday evening.

Outlook...

Wednesday...A Small Craft Advisory is in place for all ocean zones. Wind gusts up to 30 knots out of the south/southwest and seas 4 to 7 feet. May need to extend the SCA for Delaware Bay into Wednesday but have winds staying below 25 kt currently.

Wednesday night through Friday Night...No marine headlines expected.

Saturday...SCA conditions possible (25-35%) as seas especially in northern marine zones could get near 5 feet.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory from 2 PM this afternoon to 2 AM EDT Wednesday for ANZ430-431. Small Craft Advisory until 6 PM EDT Wednesday for ANZ450>455.