Area forecast discussion
National Weather Service Mount Holly New Jersey
948 am EDT Wednesday Jun 19 2013
Synopsis...
high pressure from the Great Lakes will spread into the northeast
and Middle Atlantic States, before moving east and offshore during
Thursday. Another area of high pressure from southeastern Canada is
then forecast to build over our region Friday before moving offshore
on Saturday. A return southwesterly flow around this high pressure
will then likely take shape over our area, bringing increasing
warmth and humidity into early next week.
&&
Near term /until 6 PM this evening/...
930 am update...current forecast appears to be on track. Overall
pressure rises show high pressure building in from the north. North-northeast
winds are bringing in cooler/drier air at low levels. Low clouds
are generally clearing/dissipating southward with most clouds at this time
confined to Delaware-Maryland-Virginia and extreme southern New Jersey. Some afternoon cumulus is possible
with diurnal heating of moist ground. Morning soundings from iad
and apg suggest forecast maximum temperatures in upper 70s or around 80 degree f
should be OK.
Today...leftover NE gradient stratus over the southeast 11.2 New Jersey into
vicinity kphl-kilg at 10z clears southward steadily and should be gone
by 15z. Dry northerly flow during the day with plenty of sunshine and
southeast seabreezes developing most coastal locations during middle and
late afternoon. Exception to the sunshine might be vicinity kilg where SC
near 5000 feet may persist.
50 50 blended 00z/19 NCEP MOS guidance.
&&
Short term /6 PM this evening through 6 am Thursday/...
any afternoon SC clears by midnight. Patchy fog in the Countryside is
in the gridded forecast after 08z Thursday...especially del valley seaward
in radiation cooling conditions. Enjoy this very fine sleeping weather
Wednesday night. Its difficult to foresee it any better for many-many
days into the future.
Generally 50 50 blended 00z/19 NCEP MOS guidance except GFS temperature/dew point
was used since it appeared a bit more realistic.
Temperatures tonight will be about 5 degrees below normal in the urban centers
ranging to about 12 degrees below normal in the Countryside!
&&
Long term /Thursday through Tuesday/...
a fairly quiet start to the long term period is anticipated Thursday
with an area of surface high pressure stretching across the middle
Atlantic and northeast states. Ample sunshine is expected with near
average late June high temperatures and comfortable humidity levels,
as dewpoints will mainly be running in the lower 50s. Through the
course of Thursday, this surface high pressure will gradually be
progressing east and offshore, but little change in our overall
sensible weather is anticipated for Friday, as another area of high
pressure is expected to spread into our region from southeastern
Canada. This will again yield pleasant conditions across our area
for Friday, with comfortable humidity levels and maximum
temperatures again ranging from the middle to upper 70s north and
along the coast to the lower 80s elsewhere.
By Saturday, surface high pressure will once again shift to our
southeast and offshore, but overall this system will still influence
the Middle Atlantic States and lead to another mainly quiet and warm
day. We have, however, kept slight chance probability of precipitation in place for our
northwest zones Saturday as isolated showers/T-storms may develop
around the periphery of the high pressure over the elevated terrain.
For the latter part of the weekend and into early next week, this
nearby surface high pressure to our south and east will continue to
influence our region, with a middle level ridge also spreading into the
region. A southwesterly return flow around the surface high will
bring increasing warmth and humidity to the middle Atlantic region,
with above average maximum temperatures by Monday and Tuesday,
mainly into the middle and upper 80s across the area and dewpoints
well into the 60s. In addition, the potential for scattered
showers/T-storms will be present each day from Sunday through Tuesday,
mainly during the afternoon to evening hours.
&&
Aviation /14z Wednesday through Sunday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
VFR conds noted at all taf sites except miv. Current MVFR ceilings at
miv should lift to VFR or partially clear by late morning. North-northeast
winds prevail with high pressure building in from the north.
After 13z...VFR with scattered clouds at or above 6000 feet during the day.
Northerly wind around 10kts becomes southeast late in the day in many
areas.
Tonight...any VFR scattered-broken at 6000 feet clears during the evening.
Patchy Countryside fog near 09z Thursday. Light wind.
Outlook...
Thursday and Friday...some sub-VFR conditions possible each morning
in fog/haze, otherwise VFR conditions expected.
Saturday...sub-VFR possible in the morning in fog/haze, otherwise a
mainly VFR day. Isolated late-day showers/T-storms possible.
Sunday...mostly VFR conditions; although, sub-VFR is possible in
early fog/haze or afternoon/evening shwrs/T-storms.
&&
Marine...
probably sub-advisory conditions to persist across our waters through
tonight but with concern for a period of near Small Craft Advisory conditions
between now and 9 am EDT this Wednesday morning along the S New Jersey
coast and Delaware coasts as the gradient NE flow north of surface low
sweeps southward behind the seaward departing Delaware-Maryland-Virginia surface low.
Monitoring for a possible short fuse Small Craft Advisory anz454-455 and possibly
lower Delaware Bay anz431.
Outlook...
surface high pressure will be influencing the middle Atlantic region
and our coastal waters from Thursday through the weekend. We
therefore expect sub-Small Craft Advisory levels for our coastal waters and Delaware
Bay through this period. Wind gusts through this time frame will
primarily be at 20 knots or less, with seas mainly in the 2 to 3
foot range for the coastal waters and 1 to 2 feet into Delaware Bay.
&&
Rip currents...
cautions...even if we forecast a low risk for the formation of
rip currents... low does not mean no risk!
To ensure safety...always swim in the presence of a lifeguard...
especially for weak swimmers or those not skilled at swimming in
the ocean which is far far different than the relative calm of pool
swimming.
Also alcohol and/or being tired for any reason is not a safe mix
for ocean swimming.
Participating in a National usla/NWS/sea Grant rip current meeting
yesterday...most rip current related drownings occur in 2-3 feet of
wave/swell...probably because the weather is good enough to go out
into the ocean water. Unfortunately...many are unprepared how to
handle being drawn briefly away from the beach surf zone into
deeper water.
Daily semi permanent structural generated currents always persist-
recur along jetties and piers and no one should swim there without
the supervision of a lifeguard.
Water temperatures along our New Jersey and Delaware coasts are near or a bit
above normal as of June 18.
Risk rip current formation projection the next several days is
generally low though have run with MDT along the New Jersey coast today due
to a marginal projection between low and MDT. It gets close to
moderate on Sunday along the New Jersey coast as we approach full moon.
Data into the projections are as follow
Today.....2 feet 10 second 030 13kt
tomorrow..2 feet 9 second 090 10kt
Friday....2 feet 9 second 130 9 knots
Saturday..2 feet 9 second 170 10kt
Sunday....2 feet 9 second 180 10kt
&&
Climate...
rerged...daily rer rfall ydy of 2.10 posted.
Rerilg "june" monthly rainfall posted.
Ilg 9.99 so far...prior record 9.90 in 2003. Por back to 1894.
Phl 8.31 so far...second wettest. Record is 10.06 in 1938. Por
1872.
Acy 7.19 so far...third wettest behind the 7.57 in 1935 and 8.45
in 1920. Por 1874
Abe 6.47 so far...eighth wettest. Record 10.51 in 1938. Por 1922
Ged 11.5 so far...record 14.07 in 2006. Por very short.
Ttn 7.2 so far...record 13.80 in 1996. Por 1865.
Ridge 4.99 so far...record 15.73 in 1972. Por 1869.
Mpo 7.06 so far...record 12.10 in 2006. Por 1901.
By the way...ydy-June 18 kmpo .02 and krdg only .04 .. while 1 to 3 inches
was common vicinity kphl through S New Jersey...Delaware and east Maryland. Kdov had 3.59 inches.
It also appears June temperatures will average above normal.
&&
Phi watches/warnings/advisories...
PA...none.
New Jersey...none.
Delaware...none.
Maryland...none.
Marine...none.
&&
$$
Synopsis...Kline
near term...amc
short term...drag
long term...Kline
aviation...drag/Kline
marine...drag/Kline
rip currents...
climate...
