Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
245 am EDT Friday Aug 1 2014
high pressure will shift northeast this morning as a front offshore
backs toward the coast. The front will remain stationary over
eastern North Carolina through the weekend and into early next
week. The front will dissipate by midweek.
Near term /through today/...
as of 130 am Friday...surface and satellite observations indicate the
inverted trough is located well off the NC/SC coast...with showers
and thunderstorms over the Cape Fear region spreading northeast
across Onslow/Duplin counties over the next few hours and
eventually across the coastal plain counties over the next 5-6
hours. Satellite blended precipitable water illustrates a sharp
moisture gradient between the northern obx with precipitable waters near 1.40
inches...and Pender/Sampson counties where precipitable waters are above 2
inches. This moisture rich air to the SW will shift north over
eastern NC through the early morning hours as the weak inverted
trough shifts closer to the NC coast. Winds remain mostly east to east-southeast
this morning but shift SW by roughly 700 mb. Guidance also
suggests a weak shortwave helping aid shower/thunderstorm
production across Cape Fear which should slowly translate NE over
the western portions of the County Warning Area this morning. Biggest changes for
the early morning period was to increase clouds and bump minimum
temperatures up a degree or two...mainly for inland sections where clouds
will greatly inhibit radiational cooling. Expect low 70s inland to
middle 70s along the coast and obx.
The inverted trough will shift north through eastern NC today with
precipitation chances increasing this morning and afternoon. Guidance
indicates another strong vortmax approaching the coastal plain
counties from the SW after 18z today. Rain may be heavy at times
and quantitative precipitation forecast amounts range 0.25-0.75 inches across the County Warning Area...though
could see higher amounts in strong storms. Mbe vectors greater
than 20 knots most of today but fall off quickly below 15 knots by
late afternoon when back-building/training of cells may be possible.
Maintained chance probability of precipitation increasing to likely by 18z across the
region. Wide coverage of storms and limited instability should
reduce the severe weather threat although cannot rule out an isolated
damaging wind gust or even hail. Maximum temperatures will be a bit tricky
today as clouds inhibit insolation...though any breaks in the
clouds could allow temperatures to build above current middle 80s forecast.
Short term /tonight/...
as of 140 am Friday...could see a brief respite from rain for inland
locations tonight as shortwave aloft shifts off the coast...though
will maintain chance probability of precipitation inland to likely probability of precipitation along the coast
given the moisture-rich SW flow with precipitable waters above 2 inches for the
region. Heavy downpours and localized flooding concerns will
continue this evening as mbe vectors fall below 10 knots for the
short term. SW flow strengthens overnight with the surface front
located west of the County Warning Area...nearly along the I-95 corridor. Guidance
indicates channeled weak vorticity aloft will shift over the
region and may aid in maintaining scattered showers and
Long term /Saturday through Thursday/...
as of 245 am Friday...the upper trough remains to the west through the
weekend with a rich supply of deep Gulf/Caribbean moisture
continuing to train into the southeastern US. The area
continues to be in the favorable right entrance region of jet with
precipitable waters remaining above 2 inches...and conditions are expected to
remain quite wet as an inverted trough remains nearly stationary
across the area. European model (ecmwf)/wpc quantitative precipitation forecast amounts through the period are in
the 2 to 4 inch range...and as high as 5 inches. With much of
eastern NC having received copious amounts of rain over the last
several weeks...with places in the coastal plain and Crystal Coast
areas at 150-200 percent of normal rainfall...so flooding concerns
will be possible. Temperatures will be held down by the abundant clouds
and rain...which will also act to limit destabilization so no
severe weather is expected. Highs generally in the lower 80s...and
overnight lows in the 70s.
The upper trough lifts out next week with the subtropical ridge
over the western Atlantic building into the region and expect more
typical summertime diurnally driven convection to return by
midweek with temperatures climbing back to seasonable norms.
Aviation /07z Friday through Tuesday/...
short term /through 06z Saturday/...
as of 140 am...VFR conditions early this morning will lower to
MVFR in lowered ceilings late this morning for oaj/isolated then by
early afternoon for isolated/pgv as showers and thunderstorms traverse
eastern NC taf sites. The offshore inverted trough will begin to
back toward the coast this morning and shift northwest through the region
today. In addition...a shortwave in developing moist upper SW flow
will bring increasing chances for showers and thunderstorms (and sub-VFR
conditions) especially this afternoon. MVFR conditions will be
possible this afternoon through tonight given moist southerly flow
with scattered showers and thunderstorms expected across the
Long term /Saturday through Tuesday/...
as of 245 am Friday...an inverted trough of low pressure remains
across the region through the weekend...with enc in favorable
regime for widespread showers and thunderstorms with periods of
sub-VFR conditions likely through Monday. The trough begins to
weaken gradually through the middle of next week...with shower
and thunderstorm chances gradually diminishing.
short term /through tonight/...
as of 140 am Friday...latest surface and buoy data indicate east/east-southeast
flow across the waters 10-15 knots with higher gusts offshore...and
seas 3-5 feet. The inverted trough well offshore will shift north
through the waters today...shifting winds more southeast 10-15 knots today.
Winds shift more southeast/S tonight as the front stalls well inland from
the coast. Seas remain 2-4 feet range today and tonight.
Long term /Saturday through Tuesday/...
as of 245 am Friday...a coastal trough will reside across eastern North
Carolina through much of the long term bring periods of unsettled
weather in form of showers and thunderstorms this weekend into
early next week. Winds and seas should remain sub Small Craft Advisory through the
long term period with winds generally 15 knots or less. Seas will
remain the 2 to 4 foot range much of the period. Might start to
see building seas Tuesday...up to 5ft...with increasing swell from
distant tc Bertha.