textproduct: Newport/Morehead City

WHAT HAS CHANGED

The Gale Warning has been expanded to include the Pamlico Sound.

KEY MESSAGES

1) Strong cold front to impact the area today with scattered showers and thunderstorms

2) Another frontal system to impact ENC late-week

Marine: Elevated winds and seas expected through Tuesday, with a period of gale-force winds expected for a portion of the area late today into tonight.

DISCUSSION

KEY MESSAGE 1...A strong cold front, currently oozing southeast across the Ohio Valley, is expected to reach ENC late this morning, then continue southeast through the day. The front may slow down some as the strongest frontal forcing shifts away from the area, but should move offshore by early this evening. A warm westerly flow ahead of the front will lead to one more day of well above normal temperatures. In fact, some areas along the immediate coast, especially the Crystal Coast, could be warmer today than yesterday thanks to a pinned seabreeze and the westerly flow. I would not be surprised if a few areas just inland of the Crystal Coast flirt with 90 degrees (ie. Jacksonville to New Bern/James City).

Modest moisture advection ahead of the front should allow PWATs to exceed 1" across the area. The westerly flow will tend to offset low- level moisture advection, but dewpoints should manage to reach the upper 50s to low 60s. These values beneath modestly steep mid-level lapse rates should support an area of pre-frontal weak instability (MLCAPE of 250-500j/kg). Meanwhile, modest westerly flow aloft should support effective shear of around 40kt. This combination is supportive of thunderstorm organization. However, the lack of higher instability plus warm low-level temps and some residual capping should tend to offset deeper convection from developing. With this in mind, scattered thunderstorms are still expected, but the risk of severe weather continues to look low. The greatest risk looks to be strong downburst winds (40-45 mph) thanks to very steep low-level lapse rates. A reasonable worst case scenario is for a few 50-60 mph wind gusts to occur should stronger instability develop.

Behind the front, a much colder and drier airmass will move in on gusty northerly winds. Across the northern half of ENC, temperatures are expected to fall through the afternoon as the front moves through there first. In fact, the NRN OBX may fall into the 40s by the afternoon (after starting the day near 70).

KEY MESSAGE 2...Another cold front is forecast to ooze south across the Carolinas later this week (mostly likely on Friday). Similar to today's front, above to well above normal temperatures are expected just ahead of the front, followed by noticeably cooler conditions behind it. Scattered showers and thunderstorms may accompany that front as well, although guidance has trended a bit drier. A period of breezy northerly winds can be expected along and behind the front as well.

AVIATION /12Z MONDAY THROUGH FRIDAY/

A cold front, currently moving through the central Appalachians/Virginia area, is still on track to reach ENC by this afternoon. The latest guidance continues to point towards the front passing through ENC between 15z and 21z. Some guidance have slowed down with the front just a touch, but not drastically so. Ahead of the front, gusty SW to W winds are expected, with peak gusts of 20- 25kt. A northerly wind shift will occur with the front, and will be followed by a period of gusty N to NE winds. Peak gusts behind the front are expected to be in the 25-35kt range. Of note, SCT TSRA along the front may lead to areas of enhanced wind gusts as high as 40kt. Brief reductions to VIS and CIGs will be possible with any SHRA or TSRA as well.

Outlook: There may be another risk of sub-VFR conditions Tuesday night into Wednesday night associated with a coastal trough that may develop offshore and attempt to migrate inland. Guidance is mixed on whether or not this trough will develop, though. If the trough does, indeed, develop, there would also be an accompanying risk of SHRA, especially along the coast. After mid-week, the next opportunity for sub-VFR conditions looks to be Friday or Saturday as another cold front moves in with SCT SHRA and TSRA.

MARINE

A strong cold front, currently moving through the Ohio Valley, will reach the ENC waters by early this afternoon, then push south of the area by this evening. Moderate southwesterly winds (15-25kt) ahead of the front will continue into this afternoon. Behind the front there will be a stout northerly wind shift, with winds building to 20-30kt. Frequent gusts up to 35kt are expected for a portion of the area. A Gale Warning remains in effect where the risk of frequent 35kt gusts is the highest. Of note, the water temperatures in the Pamlico Sound have warmed well into the 50s and 60s, and wind gusts have been over- performing in the pre-frontal regime this morning. With strong mixing expected over the warmer waters behind the front, it appears the risk of frequent gale-force gusts has increased over the sound, and the Gale Warning has been expanded. Outside of the Gale Warning, occasional gusts to 35kt will be possible, but not as frequent or as long in duration.

Ahead of the front, seas of 3-5ft are expected. Behind the front, seas are forecast to build to 6-9ft north of Cape Lookout. South of there, seas of 3-6ft are expected.

Scattered thunderstorms are expected to accompany the cold front, with areas of enhanced wind gusts possible.

Outlook: High pressure builds in on Tuesday with winds and seas gradually laying down. Coastal troughing may develop mid-week, eventually leading to southerly winds returning as the trough moves inland. The next notable cold front is forecast to move through the ENC waters on Friday, with very similar impacts to today's front.

CLIMATE

Record High temps for 03/23 (Monday)

LOCATION TEMP/YEAR Morehead City 75/2012 (COOP - Not KMRH ASOS)

MHX WATCHES/WARNINGS/ADVISORIES

NC...None. MARINE...Small Craft Advisory from 2 PM this afternoon to 11 AM EDT Tuesday for AMZ131-230-231. Gale Warning from 5 PM this afternoon to 2 AM EDT Tuesday for AMZ135. Small Craft Advisory from 8 PM this evening to 8 AM EDT Tuesday for AMZ136-137. Small Craft Advisory from 2 PM this afternoon to 8 PM EDT Tuesday for AMZ150. Small Craft Advisory until 5 PM EDT this afternoon for AMZ152- 154-156-158. Gale Warning from 5 PM this afternoon to 8 AM EDT Tuesday for AMZ152-154-156-158.