textproduct: Wakefield

WHAT HAS CHANGED

A Dense Fog Advisory has been issued for portions of central VA (north of Richmond) through 9 AM this morning.

Marine Dense Fog Advisories are in effect for much of the VA and MD waters.

KEY MESSAGES

1) Areas of fog prevail this morning, mainly across the north, but also in the vicinity of the Bay and Ocean (for VA-MD).

2) A stretch of very warm, but changeable weather will prevail through the middle of next week. However, a slow- moving front will linger near and north of the area, bringing about periodic bouts of onshore flow along the coast. This will likely result in significantly cooler temperatures near the coast, particularly across the Lower Eastern Shore.

3) Chances for showers (and possibly a few thunderstorms) increase later this weekend.

DISCUSSION

As of 340 AM EST Thursday...

KEY MESSAGE 1...Areas of fog prevail this morning, mainly across the north, but also in the vicinity of the Bay and Ocean (for VA-MD).

Early morning analysis shows a sfc boundary nearly stationary across southern VA, roughly along the US-460 corridor. Light southerly winds are in place to the south of this so fog will be minimal for NC and far southern VA. However, along and N of the front, at least patchy dense fog can be expected through the next several hrs. At this time, a Dense Fog Advisory has been issued for portions of central VA to the N of metro RIC. Fog has been locally dense over the Peninsula and middle Peninsula as well as the lower eastern shore along the Atlantic coast. These areas will continue to be monitored for additional fog products as conditions warrant. Overall, conditions should begin to improve after sunrise, but at least patchy fog is likely to persist through 8-10 AM (lingering thr longest over the north and eastern shore).

KEY MESSAGE 2...A significant warmup will continue through this weekend and into the middle of next week. However, a slow- moving front will linger near and north of the area, bringing about periodic bouts of onshore flow along the coast. This will likely result in significantly cooler temperatures near the coast, particularly across the Lower Eastern Shore.

Later today, the front is forecast to move back north, as the H5 flow (that is current zonal), becomes more WSW to SW as the next shortwave over the midwest moves to the east and the upper level ridge to our south amplifies off the SE US coast. This should allow for increasing SW low level flow, and high temperatures getting even warmer than yesterday for most of the region. Expect the sky to become partly to mostly sunny later this morning, although this will take longer to the N and on the eastern shore where low clouds could linger into the early aftn. Highs should reach into the upper 70s to around 80F for areas W of the Bay and along/S of I-64. Highs will be cooler on the eastern shore (generally in the 60s). That next shortwave passes by N of the region overnight and on Friday. This will again likely push the boundary back to the SW on Friday, earliest on the ern shore where highs may not get out of the 50s, but much later for south central VA and interior NE NC. The 00Z models continue to vary with respect to how far south and west and with the timing that the cooler air evolves on Friday. The GFS/NAM are the most aggressive with cold air extent vs the warmer ECMWF and CMC/HRRR. For now, highs are forecast into the lower 80s for much of the CWA, with a sharp gradient to the N/NE of I-64. Much of east central VA and even SE VA at the coast could see a fast warmup well into the 70s with temps falling significantly by mid to late aftn. Aftn shower chances are mainly across the northern 1/2 of the area, shifting to the eastern shore Fri night. There is decent instability to the south of the front, but the precip looks ana-frontal at this time so did not add any tstms to the forecast.

KEY MESSAGE 3...Chances for showers (and possibly a few thunderstorms) increase later this weekend.

After the warmup (for areas that trend cooler Friday), a more prominent upper trough dives SE and flatten the ridge for the 2nd half of the weekend. Rain chances increase more significantly late Saturday through Saturday night, with the highest chances (30-50% PoPs Sat night NW, pushing to the S on Sunday (40-60%) as a frontal boundary pushes across from the NW. Tstms Sun aftn are most likely for southern VA and NE NC, though there does not appear to be much if any SVR threat at this time. This front likely stalls or dissipates over the area early next week, which will potentially lead to additional chances of rain into Monday. Ensembles are not showing a heavy rainfall signal at this time, generally averaging ~0.1" to 0.3" through the period. It remains very warm through the middle of next week, with some record highs possible (records are mostly only in the low 80s).

AVIATION /08Z THURSDAY THROUGH MONDAY/

As of 100 AM EST Thursday...

Variable conditions early this morning, with local IFR-LIFR and still many sites at VFR. Guidance is split regarding how quickly conditions will improve at SBY Thursday morning. For now, have cleared to MVFR by midday, but potential that IFR could linger a bit longer, and this will need to be monitored for the next issuance. Some reduced visibility/ceilings at PHF and RIC continue (at RIC right around sunrise) this morning. Winds are light and variable, with SW flow resuming with onset of diurnal heating later this morning.

Outlook: The front will linger across the north and bring some potential for isolated to scattered showers, mainly impacting SBY but low chance for RIC as well. A backdoor cold front is expected to shift the winds to the E-NE on the Lower Eastern Shore Fri aftn, with additional flight restrictions possible. It is uncertain how much progress farther south the boundary makes Friday afternoon but in general, the chances are lower at the remaining terminals. Saturday should be mainly VFR, then rain chances increase, possibly with a few tstms Saturday evening through Sunday.

MARINE

As of 240 AM EST Thursday...

Key Messages:

- Marine fog remains a concern today and additional rounds are possible through the rest of the week.

- A sub-SCA wind and sea state is expected through Saturday. The next potential for SCAs is Saturday night into Sunday.

A wavy backdoor cold front resides just N of the NC-VA border this morning. S of the boundary, light southerly flow is observed. Light flow is also observed N of the boundary, though the wind direction is E-NE. A persistent area of marine fog has developed in the lower Chesapeake Bay and James and York Rivers, with areas of fog also in the northern coastal waters. Dense Fog Advisories have been issued where cameras, observations, and satellite data corroborate ongoing fog. Fog could expand northward as the boundary slowly lifts N this morning, but confidence is not particularly high in these light flow setups. Will monitor through the day and adjust advisories as necessary.

As mentioned above, the boundary will slowly lift northward today and tonight. This will shift winds to the S or SW for the entire marine area by this afternoon. While wind speeds stay sub-SCA, could see occasional gusts to 20 kt by the evening hours and especially tonight as weak low pressure passes N of the area. The boundary again drops SW Friday and winds likely become E-NE 10-15 kt by the afternoon and evening. Southerly flow returns Saturday and increases to 15-20 kt Saturday afternoon through early Sunday morning. SCAs appear probable for the coastal waters Sat night as sustained winds increase to around 20 kt with ~5 ft seas (especially N), with SCAs also possible on the Chesapeake Bay and rivers due to 20-25 kt gusts. Lighter winds return Sunday-Monday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...Dense Fog Advisory until 9 AM EST this morning for VAZ048-062- 064-509>511. MARINE...Dense Fog Advisory until 10 AM EST this morning for ANZ630-631- 635-636-650-652-654-656. Dense Fog Advisory until 7 AM EST this morning for ANZ632-634- 637. Dense Fog Advisory until 4 AM EST early this morning for ANZ638.