Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Wakefield Virginia
636 am EDT Sat Aug 23 2014

Synopsis...
a frontal boundary across the Middle Atlantic States will move southwest
of the area today. High pressure from New England slowly builds
into the area tonight into Sunday...before settling over the
Piedmont early next week.

&&

Near term /until 6 PM this evening/...
latest surface analysis reveals hi pressure centered over New England and a
disorganized pressure field over the middle Atlantic region coinciding
with a weak stalled frntal boundary. Aloft...northwest flow continues with
an upper-level ridge centered over the east-central Continental U.S.. the surface front
will sag S into the Carolinas today. Expect another day with scattered
shras/tstms...especially over the Piedmont closer to the front. The
potential for thunder will be confined away from the csts due to
NE flow with hi pressure building over New England. Not expecting any severe
weather but heavy rain is possible in some areas. Afternoon hi temperatures will range
from the upper 70s to near 80 over the lower Eastern Shore to the low-middle 80s
elsewhere.

&&

Short term /6 PM this evening through Monday/...
the high surges south-southwest over the area tonight into Sunday with the
surface ridge axis settling over the Piedmont by Monday. This will
produce a drying trend along with a NE wind that should be rather
breezy along the coast. Partly to mostly sunny conditions are
expected by Sunday...with mostly clear/sunny conditions by Sunday
night and Monday.

Highs will be below seasonal averages through Monday (around -1
St dev). Highs Sunday and Monday will range from the upper 70s to
low 80s. Lows should be in the middle/upper 60s Sunday morning...with
mainly low/middle 60s expected Monday morning.

&&

Long term /Monday night through Friday/...
surface high pressure and upper level ridging along the eastern Seaboard
is expected to continue through middle next week. This pattern will
maintain a cooler airmass over the area through Wednesday before the
ridge axes at the surface and aloft aloft begin to shift just east of
the forecast area...and moving offshore by Thursday. The forecast is generally dry
through the extended forecast periods due to well-established
subsidence through the atmospheric profile...however a few showers
cannot be ruled out near the far southeast Virginia/NE NC coast on Wednesday due to
the potential for wraparound moisture from the tropical system
passing well to the east. High and low temperatures will run below
normal from Monday night through Wednesday night (lows in the 60s...upper
50s far western counties/highs in the low-middle 80s...mid-upper 70s
beaches) and then rebound toward seasonal normals Thursday/Thursday night
(highs in the middle-upper 80s...upper 70s-lower 80s beaches/lows in
the middle-upper 60s...around 70 beaches).

&&

Aviation /12z Saturday through Wednesday/...
kept a tempo group for -ra next few hours at kric as the batch of
rain crosses the Piedmont. Otw...high prs to the NE allowing for
dryer air along the coast with mainly VFR cndtns this am. Expect
VFR ceilings today with tsctns showing plnty of moisture around the area
for a broken SC deck (3-4k ft) through much of the forecast prd with MVFR
ceilings returning after 00z. Scattered convection possible after 18z...but
timing of any shower/tstrm problematic at this point so kept precipitation
out of forecast after 18z.

Outlook...MVFR/IFR conditions possible due to stratus/fog Sun morning.
Otw...dry weather is forecast for several days beginning Sunday.

&&

Marine...
frontal boundary now south of the area with high pressure building
south from New England. Despite the ongoing east-NE winds...latest
guidance not as bullish with the winds thus creating some doubt
when Small Craft Advisory conditions will start. Toughest call will be southern ches
Bay where only minimal conditions will be meet. Mouth of the Bay
will have an earlier start and later finish time. Seas (especially
out near 20 nm) are expected to build to 5 feet then remain there
through early next week...so extended the Small Craft Advisory headlines over the
waters through Sunday night. For continuity sake...went ahead and
hoisted Small Craft Advisory headlines for Currituck sand sun and Sun night as secondary
surge will likely keep winds between 15-20 kts.

Forecast next week will depend on the track of a developing
(tropical) low prognosticated to track NE but remain east of Gulf Stream
wall. Swell from this system will eventually affect the middle atlntc
beach areas.

&&

Tides/coastal flooding...
tides prognosticated to build to about 1 foot above normal early next week
as the NE flow continues. Despite the persistant onshore flow...levels
expected to remain about 1/2 foot below minor flooding thresholds.

Went with a moderate rip current threat today given nearshore waves
of 2-3 feet and a increasing NE wind flow.

&&

Akq watches/warnings/advisories...
Maryland...moderate rip current risk through this evening for mdz025.
NC...moderate rip current risk through this evening for ncz102.
Virginia...moderate rip current risk through this evening for vaz098>100.
Marine...Small Craft Advisory from 6 PM this evening to 2 am EDT Monday
for anz634.
Small Craft Advisory from 8 PM this evening to 6 PM EDT Sunday
for anz632.
Small Craft Advisory from 8 am Sunday to 6 am EDT Monday for
anz633.
Small Craft Advisory from 8 PM this evening to 6 am EDT Monday
for anz654.
Small Craft Advisory from 2 am Sunday to 6 am EDT Monday for
anz656-658.
Small Craft Advisory from 6 PM this evening to 6 am EDT Monday
for anz650-652.

&&

$$
Synopsis...ajz/mas
near term...mas
short term...ajz/mas
long term...bmd
aviation...mpr
marine...mpr
tides/coastal flooding...

National Weather Service Glossary of Abbreviations