Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service Newport/Morehead City NC
104 am EDT Friday Apr 25 2014

Synopsis...
high pressure will be centered off the coast tonight. A weak cold
front will move through from the west Friday night. A secondary
stronger cold front will cross the area Saturday night stalling
south of the region Sunday. Developing low pressure in the plains
will push a warm front north into the area Tuesday...with a cold
front approaching late Wednesday into Wednesday night.

&&

Near term /until 6 am this morning/...
as of 1 am Friday...only minor adjustments to current forecast.
Based on current observations...have lowered minimum temperatures
overnight a couple of degrees...except have raised several degrees
Outer Banks. Temperatures may level off later tonight as flow
becomes more southerly toward morning. The 3 km hrrr tries to
bring some light showers into the far southern counties by around
11z but will hold off for now.



&&

Short term /6 am this morning through 6 PM Saturday/...
as of 300 PM Thursday...dampening short WV trough and assctd surface cold
front will move in during the day. Storm Prediction Center upgraded severe outlook to
slight risk over area and concur on marginal severe threat during afternoon
with forecast sounding convective available potential energy to around 1200 and shear around 40 knots.
Continued previous forecast probability of precipitation with 20% over SW half of area during
morning with initial warm air advection...then 30-50 probability of precipitation for thunderstorms during
afternoon...highest over western sections. Temperatures will be able to rise to
around 80 inland sections even with some cloudiness...and around 70
Outer Banks.

&&

Long term /Saturday night through Thursday/...
as of 230 PM Thursday...scattered rain showers/thunderstorms and rain will be ongoing early Friday evening
ahead of approaching cold front...espcly NE tier closer to short
wave and better forcing. Could still be small chance of strong to severe
storm early but with instability waning threat shld end quickly after
sunset. All precipitation shld exit by around midnight as front/short wave
move offshore with clearing skies and lows middle 50s inland to around
60 beaches. Weak high will pass offshore to the S Sat with plenty of
sun and mild temperatures around 80 inland to upper 60s/lower 70s beaches.
Secondary dry cold front will sag S through the region Sat night and
stall to the S Sunday. Thicknesses drop a bit behind this front
espcly NE tier with highs ranging from lower 60s NE CST to middle/upper
70s SW. Ridge of high pressure near region Sun night into early Monday will
slide offshore later Monday. Will start to see moisture increase later
Monday espcly inland and continue small pop mainly west of Highway 17 in the
afternoon. Isent lift will increase Monday night as frontal zone stalled to
the S becomes more defined. Although fairly far out in time both
GFS/European model (ecmwf) focus precipitation across northern tier Monday night and followed this
with chance probability of precipitation north and west to slight chance southeast.

Tuesday through Thursday looks unsettled as stacked upper low stalls near southern
Great Lakes with frontal zone extending from this low to near or
just north of the region. Moist SW flow aloft will lead to bouts of rain showers
and poss thunderstorms and rain through the period and have probability of precipitation mainly in the chance to
good chance range this far out. Some indication that wave will develop
on front and push bulk of moisture off the CST later Thursday but too
early to really jump on that. Will be mainly in warm sector Tuesday into
Thursday however clouds and precipitation will keep temperatures near normal with highs
in the 70s inland to upper 60s/near 70 beaches.

&&

Aviation /06z Friday through Tuesday/...
short term /through 00z Saturday/...
as of 1 am Friday...will continue previous trend showing some MVFR
ceilings late at kewn/koaj as low-level moisture increases. The 3
km hrrr model shows some showers trying to sneak into the region
but will hold off for now. May mix out the lower cloud layers
before midday Thursday but scattered showers/thunderstorms will develop
during the afternoon and bring periods of possible sub-VFR. Will
just have vcsh for now until better timing of precipitation and lower
ceilings can be resolved. S/SW winds increase Friday with gusts near
25 knots likely during the afternoon.

Long term /Friday night through Tue/...
as of 230 PM Thursday...scattered MVFR poss early Friday evening with rain showers/thunderstorms and rain
then VFR from M Idaho evening on as moisture slides offshore. High pressure
will dominate Sat though Monday with mainly VFR expected. Warm front
will lift north through the region later Monday night and Tuesday with increasing
chance of rain showers and poss thunderstorms and rain with some reduced flight categories
likely.

&&

Marine...
short term /through Friday/...
as of 1 am Friday...no big changes made to marine forecast. Winds
continue southeast at 5 to 10 knots with seas generally 2 to 3
feet on all waters. An approaching cold front will then produce
increasing S-SW winds on Friday. Model blend indicates winds 15-20
kts with gusts to 25 knots likely for southern and central waters by late
afternoon...and posted Small Craft Advisory there at 5 PM and continuing into Friday night.

Blend of nwps and Swan used for seas. Heights will subside to 2-3 feet
tonight...then build again Friday with 4-6 feet likely outer portions
of southern and central waters by Friday evening.

Long term /Friday night through Tue/...
as of 230 PM Thursday...brief Small Craft Advisory expected first part of Friday night central
and southern tier with gusty SW winds 20 to 25 kts ahead of cold front in
the evening. These winds will build seas to 6 feet outer waters S of
Oregon Inlet. Winds will gradient shift to northwest 15 to 20 kts in wake of
front later Friday night with seas subsiding to 3 to 5 feet by Sat morning.
Weak high will cross to the S Sat with winds becoming SW at or below 15 kts
and seas subsiding to mainly 2 to 3 feet. Secondary cold front will
sag south-southeast through the region later Sat night. West-southwest winds could reach 15 to
20 kts ahead the front Sat night with north-northeast winds close to 15 to 20
kts central and northern tier behind front early Sunday. Seas mainly 2 to
4 feet Sat night and Sunday...poss some 5 footer outer central and northern
waters. High pressure will linger near the region Sun night through Monday with
light winds and seas dropping to 2 to 3 feet. Warm front will lift north
through the area Tuesday with S winds increasing to near 20 kts and seas
building 3 to 5 feet.

&&

Mhx watches/warnings/advisories...
NC...none.
Marine...Small Craft Advisory from 5 PM this afternoon to 6 am EDT
Saturday for amz152-154-156-158.

&&

$$

Synopsis...jbm
near term...ctc
short term...jbm
long term...rf
aviation...ctc/btc/bm
marine...ctc/btc