Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 181209 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 809 AM EDT Mon Mar 18 2024 .SYNOPSIS... A reinforcing cold front moves through the region today. Several upper level disturbances and cold fronts will pass through the region this week as surface high pressure builds to the west. Developing low pressure approaches for the end of the week and weekend. && .NEAR TERM /THROUGH TONIGHT/...
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Snow showers have made their way into the Poconos so have upped sky cover and POPs for today. No other changes at this time. An upper trough to the west of our area will push east today and move offshore tonight. High pressure builds across the area thru the period. Overall, a dry forecast today as west to northwest winds increase over the area. Cooler and much drier air will continue to arrive today and then winds will diminish tonight. We have undercut much of the dew point guidance with dew points dropping in to the teens or low 20s by this afternoon. Winds will increase to 10 to 15 mph with gusts to 25 mph. Sky cover will be mostly sunny early, but then increasing clouds for the afternoon, especially for North/West areas. Highs will be close to normal with upper 40s/low 50s in many areas. For tonight, the upper trough crosses the area and high pressure ridges in from the Ohio Valley. After some evening clouds, skies will become mostly clear. Cold temperatures are expected with readings dropping to the mid/upper 20s for the N/W areas to near freezing across Philly metro and Delmarva. Winds will be West to Northwest around 5 mph.
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&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... A deep upper trough will encompass the Northeast, Mid-Atlantic, and Great Lakes for the Short Term period. Several disturbances will push weak cold fronts through the region Tuesday afternoon, then again on Wednesday afternoon and evening. Canadian high pressure then builds into the Northern Plains and western Great Lakes Wednesday night. Conditions will mostly be dry on Tuesday, although Lake Effect streamers will develop off of Lake Erie and may dip down into the southern Poconos Tuesday afternoon. A gusty westerly flow of 15 to 20 mph with gusts as high as 30 mph will be in place, and cold air advection will keep temperatures generally in the 40s to around 50, which are 5 to 10 degrees below normal for this time of the year. By Wednesday, some weak warm air advection will allow temperatures to climb by a few degrees compared to Tuesday. Another cold front will pass through the region late Wednesday and Wednesday night as low pressure passes north of the region. This may touch off some more rain showers down to the I-95 corridor and snow showers in the southern Poconos. QPF will be minimal. A gusty west flow will turn northwest Wednesday night with speeds 15 to 25 mph with 25 to 35 mph gusts. && .LONG TERM /THURSDAY THROUGH SUNDAY/... High pressure passes north of the region Thursday through Friday. Cold air advection redevelops on Thursday with potentially the coldest day of the week with highs in the low to mid 40s. Northwest winds will continue to range from 15 to 25 mph with 25 to 35 mph gusts, though a few peak gusts could reach 40 mph. With high pressure moving offshore Friday, return flow sets up and temperatures begin to warm back up to normal levels for the end of the week and weekend. Unsettled conditions on tap for the upcoming weekend as developing low pressure looks to take a run at the Mid-Atlantic and Northeast. However, there is much uncertainty among the models as to the track the low will take. Will follow the NBM and cap PoPs at chance. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas... .Rest of Today...VFR expected. Mostly high clouds early then increasing Cu/Sc clouds for the late morning and into the afternoon. Northwest to West winds increasing to 10 to 15 kts with gusts to 25 kts. High confid. .Tonight...VFR expected. Decreasing clouds and winds. Northwest to West winds 5 to 10 knots. High confid. Outlook... Tuesday through Friday...VFR overall. A few SHRA or SHSN Tuesday afternoon, and again Wednesday afternoon and evening could result in brief sub-VFR conditions. A prolonged period of W-NW winds will range from 15 to 20 kt with 25 to 35 kt gusts. && .MARINE... Low pressure moving along the front to the south will move offshore early today. High pressure builds in later today and tonight. Winds will increase thru the day as colder air arrives across the waters. We`ll probably remain below SCA much of today but some gusts around 20 kts are possible early this morning. Late this afternoon and for tonight, SCA winds and seas are expected to develop. SCA will be issued with the 330 AM fcst. Fair weather is expected today and tonight. Outlook... SCA continues into Tuesday, and SCA conditions expected through Thursday with persistent W-NW winds. Gales are possible from time to time, especially Wednesday or Wednesday night. Conditions could subside below SCA levels Friday. && .FIRE WEATHER... Lowering humidity levels and increasing winds this afternoon could lead to fire weather concerns across our region. The lack of rainfall during the past week has led to dry fuels over the region. After coordination with the fire weather partners later this morning, the fire weather products will be updated and there is a possibility of an SPS being issued. A few rain or snow showers are possible across the Poconos from time to time this week. Aside from that, dry conditions on tap. Although most of the area is above normal for precipitation since March 1, it has been a week since the last significant rainfall, and no significant rainfall is expected this week. Min RH values this week will generally range from 25 to 35 percent, and stronger westerly flow occurs over the area as well with winds generally 15 to 20 mph with gusts 25 to 30 mph. The day of highest concern looks to be Thursday, where surface dew points drop into the upper single digits to low teens. Min RH values may be as low as 20 to 25 percent, and west to northwest winds could gust as high as 30 to 35 mph. By then, it will be almost 2 weeks since the last significant rainfall. Depending on how fast and how efficiently fine fuels dry out will add to possible concerns for the rapid spread of any fires that may develop. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory from 6 PM this evening to 6 PM EDT Tuesday for ANZ430-431-450>455. && $$ SYNOPSIS...MPS NEAR TERM...OHara/RCM SHORT TERM...MPS LONG TERM...MPS AVIATION...MPS/OHara/RCM MARINE...MPS/OHara FIRE WEATHER...

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