Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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543 FXUS61 KPHI 291217 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 817 AM EDT FRI JUL 29 2016 .SYNOPSIS... Low pressure near the Delmarva will strengthen as it moves east off the New Jersey coast today. Another area of low pressure will develop near the Delmarva Saturday night and slowly drift out to sea through Monday. Drier and less humid weather is expected by the middle of next week as high pressure builds over the region. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 8 AM update...have cancelled the flash flood watch for locations where the heaviest rain has moved out. The watch remains in effect for portions of the NJ coastal plains through noon. previous near term discussion...Surface low pressure was located off the Delaware coast around 6:00 AM. The feature will move east northeastward and it should pass farther off the coasts of Delaware and southern New Jersey this morning before moving quickly out to sea. A band of moderate to heavy rainfall was located in the lift to the northwest of the low. It extended from the upper Delmarva up into southeastern Pennsylvania and New Jersey around 6:00 AM. As the low makes its way out over the ocean, the precipitation will pull away to our northeast and east during the late morning and afternoon hours. The cloud cover is forecast to lift and break gradually with some sunshine developing during the afternoon. The wind is anticipated to favor the northeast to northwest quadrant for today. Speeds may increase to 10 to 15 MPH on the coastal plain and 5 to 10 MPH inland. The cloud cover and the northerly flow should keep temperatures from rising above the 80s this afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... We should remain between weather systems for tonight with the low moving farther out to sea. Weak areas of low pressure are forecast to be over the Ohio River Valley and eastern Virginia and North Carolina. High pressure is expected to be to our north. We are anticipating a partly to mostly cloudy sky with a light wind. A few light rain showers may begin to push into our region from the west after midnight. Minimum temperatures are forecast to be in the middle and upper 60s in the north and in the lower 70s in the south. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Highlights... * Scattered showers and thunderstorms with potential for locally heavy rainfall this weekend * Transition to drier and less humid weather trending a bit slower during the early to middle part of next week Details... Saturday and Sunday... A couple of additional shortwaves will move across our region this weekend along with a frontal boundary in the vicinity. Right now,it appears that the timing for the increased threat of showers and thunderstorms will be from Saturday afternoon through Sunday evening. Plenty of moisture will linger through the weekend, so the threat will remain for locally heavy rainfall. Cloud cover and showers and thunderstorms will help hold temperatures in the 80s across much of the region. But, humid conditions will persist with dew point temperatures hovering around 70 in many locations. Monday through Thursday... Each model run is trending a bit slower with the eventual transition to a drier weather pattern and the 29/00Z guidance is no different. Will keep at least a slight chance of showers and thunderstorms in the forecast through Tuesday. Likely will see diurnally driven showers and thunderstorms on Monday and then potentially another uptick on Tuesday as an upper level trough finally pushes through to sweep the stagnant frontal boundary to our south. High pressure will build over the region, bringing us drier and somewhat less humid weather. Look for high temperatures in the lower to mid 80s and dew point temperatures in the lower to mid 60s, which will be quite a change from the week to 10 days preceding it. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. An area of moderate to heavy rain will continue to move eastward across our TAF sites early this morning. It was already east of KRDG and KABE at 1000Z. Conditions will favor the IFR and MVFR categories. The rain is forecast to begin moving out of our region and to our northeast and east during the mid to late morning. Conditions should begin to improve gradually at that time and we are anticipating VFR conditions for the afternoon hours. VFR conditions are forecast to continue into tonight. However, some MVFR visibility restrictions may develop. The wind is expected to favor the northeast to northwest quadrant for today at speeds of 6 to 12 knots. Outlook... Sat through Sun...Shra/tsra will lower cigs/vsbys at times Moderate Confidence. Mon...Mainly VFR. Moderate Confidence. && .MARINE... Rain with embedded thunderstorms is anticipated for this morning. The precipitation should move to our northeast and east during the afternoon. Low pressure was passing off the coast early this morning and it will move out to sea. A northeast to north wind is expected for today on the coastal waters of New Jersey and Delaware with speeds increasing to 10 to 20 knots. Wave heights are anticipated to build to around 3 feet on our ocean waters. Wind speeds are expected to diminish to 10 knots or less for tonight and the direction may go variable for a time. Outlook...Saturday through Tuesday... Winds come up a bit with the weak low pressure development nearly over the waters on Sunday, otherwise expect generally a light wind flow for much of the period. Biggest concern for mariners will be the risk for thunderstorms this weekend. RIP CURRENTS...The prevailing risk category for the development of dangerous rip currents along the coasts of New Jersey and Delaware for today is low. However, a northeast to north wind may bring periods of moderate risk. The probably risk for the development of dangerous rip currents on Saturday is low && .CLIMATE... GED: a record daily rainfall of 2.80 inches occurred for the 28th. PHL: heading for top 10 warmest July on record. July avg temp for PHL will be about 80.9F, 8th warmest July in the period of record since 1874. ACY: already is at least 7th wettest July on record with its monthly record of 13.09 set in 1959. The por is back to 1874. Total for the month as of the 28th: 8.35". && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...Flash Flood Watch until noon EDT today for NJZ012>015-018>027. DE...None. MD...None. MARINE...None. && $$ Synopsis...99 Near Term...Iovino/Johnson Short Term...Iovino Long Term...99 Aviation...Iovino/99 Marine...Iovino/99 Climate... is the U.S. government's official web portal to all federal, state and local government web resources and services.