Area Forecast Discussion
Issued by NWS Mt. Holly, NJ-- Remove Highlighting --
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FXUS61 KPHI 271328
Area Forecast Discussion
National Weather Service Mount Holly NJ
928 AM EDT FRI MAY 27 2016
High pressure off the middle Atlantic coast will settle over our
region through the weekend, gradually giving way to a cold front,
that is expected to move through our area Tuesday. Canadian high
pressure is expected to settle over our region by mid week, while
a persistent area of low pressure lurks off the southeast coast.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
High pressure off the coast will continue to influence our
weather today. The circulation around the high will keep our
region in a southerly flow of very warm and humid air. We are
expecting a good deal of sunshine for today even with the
development of afternoon cumulus. Maximum temperatures around 90
degrees are anticipated except in the elevated terrain and along
The focus for the greatest instability in our vicinity is
forecast to develop from around Lancaster County and Berks County
up into the Poconos during the afternoon. Mixed layer CAPE values
may rise into the 1500 to 2000 J/kg range there. As a result, we
anticipate that any convective development this afternoon will be
in that area. The potential for rain will decrease to less than 15
percent toward the coast.
Dew point readings will remain in the 60s for this afternoon.
Precipitable water values should be around 1.6 to 1.7 inches. The
steering winds will be relatively light so any thunderstorms that
develop should be slow moving leading to the potential for locally
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
Any late day convection should diminish and end by midnight.
Otherwise fair and mild. Looks like haze and/or patchy fog early
tomorrow morning with the fog in your typical spots...northwest NJ
and also vcnty KRDG and KMIV. Min temps about 10 to 15F above
Forecast basis: a 50 50 blend of the 00z/27 GFS/NAM MOS.
.LONG TERM /SATURDAY THROUGH THURSDAY/...
The main story will continue to be above average temperatures
thru Sunday with high temperatures near 90 degrees, as well as
uncomfortable humidity levels into early next week. Temps will
remain above average into the middle of next week
The main uncertainty will be the interaction between an
approaching cold front early next week and an early season
tropical/sub-tropical system modeled to develop in the Bahamas.
The models continue the trend of drawing a plume of moisture
northward along the east coast, with PW values nearing 2.00
inches, or 2 to 3 Standard Deviations above normal by Monday. With
the approach of a cool front and weak steering currents aloft,
there is the potential for heavy downpours on Monday. Otherwise,
there is a chance of diurnally driven showers and thundershowers
Saturday and Sunday. For Saturday, this activity should be focused
northwest of I-95, while Delmarva may see an increase in activity
by late Sunday.
A cold frontal passage is anticipated Tuesday, with a drying
trend for Wednesday and Thursday. But with low pressure off the
southeast US coast, this front may get hung up close to our
region, which would lead to a more pessimistic forecast.
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Today...VFR with sct-bkn aoa 5000 ft. South to southwest wind
gusting around 15-18 kt during the afternoon. Chance of a shower
or tstm but not in the TAFS till more convinced of nearby passage
of any convection. For now we have prob30 of a mdt afternoon
shower in KRDG and KABE.
Tonight...VFR to start . Any evening convection diminishes and
ends early and am thinking mostly north of our TAF sites. Patchy
IFR conditions in stratus/fog anticipated near 09z/28 vcnty
KABE/KRDG, otherwise a bit hazy early Saturday morning. Light
south to southwest wind.
Predominantly VFR during the day through the period, with MVFR
possible Sunday night thru Monday night.
No marine headlines through tonight.
Southerly flow persists...at times gusty to 15 or 20 kt. Seas
generally 1-3 ft. More conservative NWPS wave heights were used
for this 330AM forecast.
Winds and seas are expected to remain below SCA criteria during
the Saturday thru Tuesday time frame. Some maritime fog is
possible Sunday night.
RIP CURRENTS: Issued low risk for the formation of dangerous rip
currents except for Monmouth County - moderate. Gusty southerly
winds to around 20 mph late in the day may enhance the rip current
risk elsewhere along the NJ coast.
Warmer than normal temperatures, appears to be one part of the
recipe for heightened surf zone danger. Another part: unguarded
beaches. Be smart and safe. Unless you`re an accomplished
swimmer... unguarded beach swimming is ill advised.
The water temperatures were still only in the lower 60s southern
NJ and Delaware Atlantic coasts, and the upper 50s along much of
the northern NJ coast.
The record maximum temperature today at allentown is 91, set in
1991 and 1965. It should be near record this afternoon. All other
record maximum temperatures in our county warning area (CWA) for
May 27 appear out of reach.