Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPHI 300742 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 342 AM EDT SAT JUL 30 2016 .SYNOPSIS...
-- Changed Discussion --
As a weak frontal boundary remains near our area today into early next week, a few weak low pressure systems will track along it. High pressure will build across our area Tuesday through Wednesday before shifting offshore Thursday, then a cold front is scheduled to arrive Friday night.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
The rain showers that developed along a convergence zone late yesterday persisted well into the overnight hours. Their motion and redevelopment have been difficult to forecast being that they seem to have been generating and feeding off mesoscale boundaries. The showers were located between Hershey, Hazleton and Allentown around 3:30 AM. We expect them to weaken as they continue to drift northeastward early this morning. We will mention patchy fog for the early morning hours due to the light wind and the abundant low level moisture. We are anticipating a break in the potential for showers in our forecast area for a few hours around and shortly after daybreak. The chance of showers will begin to spread into our region from the west during the mid to late morning. Showers are expected to become more numerous during the afternoon as an impulse traveling in the mid level flow begins to approach from the west. A developing south to southeast surface flow will draw additional moisture into our region. Precipitable water values are forecast to increase to around 2.0 to 2.1 inches. As a result, the rain may become heavy at times. Marginal instability is expected to develop for this afternoon so we have mentioned scattered thunderstorms. We are expecting an increase in overall cloud cover today and temperatures should not get above the 80s.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
-- Changed Discussion --
We continue to expect showers and scattered thunderstorms for tonight as a couple of mid level impulses affect our region and as a warm front approaches from the southwest and south. We will keep the mention of rain, heavy at times, due to additional low level moisture advecting into our region on a southeasterly flow off the ocean. Overnight minimum temperatures are forecast to be in the upper 60s in the Poconos and far northern New Jersey and mainly in the lower 70s in the rest of our region.
-- End Changed Discussion --
&& .LONG TERM /SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
The synoptic setup is comprised of general troughing in the Northeast to start that then becomes more amplified during early next week. This should shift offshore midweek as some ridging starts to migrate eastward from the Plains. The ridge axis may not arrive until Friday, therefore a cooler airmass is for a few days next week. We used a model blend for Sunday into Tuesday, then mostly went with the 00z WPC guidance. Some adjustments were then made however following additional collaboration with our neighboring offices. For Sunday and Monday...A couple of short waves will move across our region as a frontal boundary remains in the vicinity. The result will be some showers and thunderstorms. While the specific timing of the short waves is less certain, the more widespread convective activity should occur during peak heating and potentially be more focused initially along a weak surface convergence zone. The PW values are forecast to be around 2.00 inches and therefore locally torrential downpours can occur. While any flood threat should be localized Sunday, weak low-level flow may result in slow movers and back building of any thunderstorms. Any robust convection may produce quite a bit of lightning. Overall, the severe weather threat looks rather low at this time. For Monday, an upper-level trough sharpens and with some cooling aloft and increase in the wind fields, a few locally stronger storms may occur during the afternoon. For Tuesday through Thursday...A cold front should be south and east of our area to start Tuesday, as high pressure builds in. This surface high is forecast to be in place through Wednesday before it shifts offshore Thursday. We are anticipating some lowering of the dew points and also the temperatures. Some return flow however starts to develop on Thursday, which should allow the dew points to inch back up some. For Friday...High pressure to our south and east will yield to a warm front lifting well to our north. This will help assist in a more south-southwest flow as a cold front approaches in the afternoon, then the front should start settling across our area at night. An area of warm air advection ahead of the front will allow for afternoon temperatures to approach 90 degrees especially from the Interstate 95 corridor on south and east. The overall timing of the front will govern any convective threat as it appears that a lee side trough may not be present. We carried slight chance to low chance pops from west to east Friday afternoon and night.
-- End Changed Discussion --
&& .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Scattered showers will continue to affect areas around KRDG and KABE early this morning. Also, we are anticipating early morning ceiling and visibility restrictions at most locations. Most spots should drop into the MVFR range for a time. However, IFR conditions are possible at KRDG which received moderate rainfall during the night. The daylight hours are forecast to be mainly VFR. However, showers and scattered thunderstorms are expected to be on the increase as the day progresses. Ceilings and visibility values are anticipated to lower to MVFR and perhaps IFR tonight as a warm front approaches from the southwest and south. The wind direction should favor the south for today and it will likely become southeast for tonight. Speeds are forecast to be mostly less than 10 knots. Outlook... Sunday and Monday...Potential for MVFR ceilings to start each morning, otherwise VFR with scattered to broken cloud cover. Some showers and thunderstorms will be around especially Sunday and this will lead to mainly local and brief restrictions. Tuesday and Wednesday...VFR overall as high pressure builds in.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
The wind is expected to settle into the south and southeast for today around 5 to 10 knots. The wind is forecast to favor the southeast for tonight and speeds may increase to 10 to 15 knots as a warm front approaches from the southwest and south. Wave heights on our ocean waters are expected to be 2 to 3 feet for today and tonight. Waves on Delaware Bay should be 2 feet or less. Showers and scattered thunderstorms are anticipated from this afternoon into tonight. Outlook... Sunday through Wednesday...An onshore flow Sunday should increase some especially across the northern coastal waters, with gusts to about 20 knots. It appears at this point that that conditions remain below advisory criteria. Otherwise, a weak pressure gradient should keep winds and seas mainly below Small Craft Advisory criteria through Wednesday. Main concern will be the threat of some thunderstorms Sunday and Monday, however the greatest concentration of storms may be inland. Rip Currents... For today, there is a low risk for the development of dangerous rip currents along the coasts of New Jersey and Delaware. The wind direction should favor the southeast at 5 to 10 MPH with wave heights in the 2 to 3 foot range. We are anticipating a southerly swell with a wave period around 6 seconds. For Sunday, a low risk overall. However a moderate risk is possible mainly along the northern New Jersey coast although this will be dependent on the strength of an onshore flow.
-- End Changed Discussion --
&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...Gorse Near Term...Iovino Short Term...Iovino Long Term...Gorse Aviation...Gorse/Iovino Marine...Gorse/Iovino

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.