Area Forecast Discussion
Issued by NWS Mt. Holly, NJ
Issued by NWS Mt. Holly, NJ
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
498 FXUS61 KPHI 111901 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 301 PM EDT Tue Jun 11 2024 .SYNOPSIS... High pressure will be in control through Thursday. A gradual warming trend is expected for the remainder of this week ahead of a cold frontal passage on Friday into Friday night. High pressure will then return on Saturday and build across the region through early next week with above normal temperatures. && .NEAR TERM /THROUGH WEDNESDAY/... 200 PM...An upper level low remains situated to our north over eastern NY State with a SW to NE oriented surface trough offshore and an area of high pressure west of us over the midwestern states into the lower Great Lakes. The upshot of this is that there`s considerable cloud cover across the area due to the upper low and associated cold pool aloft combined with diurnal heating. There`s also some low level convergence that`s been setting up near the coast due to a generally NE flow coming onshore (aided by sea breezes) with NW winds trying to build in from the west with the high pressure. This will bring some isolated to scattered showers and perhaps even a few thunderstorms developing this afternoon over southern NJ, Delmarva, and perhaps as far north as the I-95 corridor by later in the day. These won`t be too widespread though as POPs are only in the 20 to 30 percent or so range for these areas. Our northwest zones from Berks County into the Lehigh Valley and the southern Poconos remain precip free. It will be an otherwise relatively cool afternoon (by June standards) with low humidity levels. Tonight, the upper low starts to migrate to the northeast and heights rise rapidly. This should cause convection to die quickly by sunset with mostly clear to partly cloudy skies overnight. Lows will be mostly in the 50s to low 60s. Enjoy it, as we`re about to flip the page to summer in a big way. For Wednesday, high pressure will be centered near the area early in the day before starting to shift offshore causing winds to turn light westerly. Expect a partly to mostly sunny day with highs mainly in the low to mid 80s as our warming trend begins. Humidity levels will remain comfortable though as dew points will still be in the 50s. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... Quasi-zonal flow will develop through the end of the week with increasing heights and thicknesses. Another trough axis will approach and cross through the region by Friday night. At the surface, high pressure will shift offshore on Wednesday night but remain in control through early Friday. A cold front will then arrive from the north and west on Friday into Friday night. This pattern will translate to a gradual increase in temperatures and dewpoints each day along with a dry forecast until Friday. Highs on Thursday will be in the 80s to around 90 degrees for most inland locations. Temps on Friday will be a bit warmer with a mix of 80s and low 90s away from the shore, however with the earlier arrival of the cold front, temps have trended a bit downward compared to yesterday. Near the shore temps will mostly be in the 70s to around 80 degrees both days. While dewpoints will be on the rise, they should top out in the 60s. This will keep heat indices close to the air temperature, so at this point, it looks like we will remain below Heat Advisory Criteria on Friday. With respect to the cold front on Friday and Friday night...there continues to be support from medium range guidance that there will at least be some convection around in the afternoon and evening. Exact convective details remain unclear especially since we are outside the timeframe of the CAMs. However, CSU-MLP guidance does have most of our area highlighted in a 5-14% corridor of severe probs. So, we will need to keep an eye on Friday`s heat and potential severe weather threats over the coming days. && .LONG TERM /SATURDAY THROUGH TUESDAY/... The upper trough will depart the region by Saturday giving way to a large and expansive upper ridge that will build across the eastern CONUS through early next week. High pressure will be located near the Great Lakes on Saturday and over the Mid-Atlantic on Sunday. This will result in near-normal temperatures for the weekend with mostly sunny skies. Surface high pressure will shift offshore early next week as upper ridge builds further resulting in increasing temps through the middle of next week. This is supported quite well by both the Climate Prediction Center and most ensemble guidance where temps may flirt with records. Little in the way of precipitation is expected other than a stray thunderstorm during the afternoon. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. This afternoon...VFR overall. Scattered showers may impact all terminals except KRDG/KABE, with an isolated t-storm possible as well, most likely at KMIV. A heavier storm could briefly reduce vsby to MVFR or even IFR, but it should be very transient should it occur. Winds this afternoon becoming mainly light NW, at around 5 knots or less, except east to southeast at KMIV and KACY. Moderate confidence. Tonight...VFR. Winds becoming NW 5 kts or less. High confidence. Wednesday...VFR. Winds mainly west around 5 knots except potential for seabreeze to affect KACY in the afternoon with winds shifting to south. Outlook... Wednesday night through Thursday night...VFR with mostly clear skies. No significant weather expected. Friday through Friday night...Sub-VFR conditions possible with a chance of thunderstorms during the afternoon and evening. Saturday through Sunday...VFR with mostly clear skies. No significant weather expected. && .MARINE... No marine headlines thru Wednesday. Winds generally below 10 kts. Seas 1-2 ft. An isolated thunderstorm possible, mainly this afternoon. Outlook... Wednesday night...No marine headlines expected. Winds around 10 kt and seas 2 feet or less. Thursday through Friday night...SCA conditions possible Thursday into Friday due to winds gusting up to 20-25 kt and seas of 3-5 feet. Fair weather expected through Thursday night with a chance of thunderstorms on Friday and Friday night. Saturday through Sunday...No marine headlines expected. Winds up to 10-15 kt with seas around 2-3 feet. Fair weather. Rip Currents... Low risk of rip currents in place for today and Wednesday. Winds will be onshore today, but with winds weak, and a short to medium period swell combined with 1 to 2 foot breakers, there is a low risk for rip currents. Similar conditions on Wednesday, though winds go more shore parallel, still less than 10 MPH. For specific beach forecasts, visit weather.gov/beach/phi && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ SYNOPSIS...DeSilva NEAR TERM...Fitzsimmons/RCM SHORT TERM...DeSilva/Staarmann LONG TERM...DeSilva/Staarmann AVIATION...DeSilva/Fitzsimmons MARINE...DeSilva/Fitzsimmons