textproduct: Wakefield

WHAT HAS CHANGED

Updated aviation discussion.

Updated climate section to include today's new record high temperatures.

KEY MESSAGES

1) A strong cold front crosses the area Thursday morning-midday, bringing a very good chance of rain, along with a low-end potential for some stronger storms during the first part of Thursday. A few snowflakes may mix in Thursday afternoon but no accumulation is expected. Cooler temperatures and dry weather return to end the week.

2) There is a low-end chance (15-25%) of isolated showers/thunderstorms across the extreme northern portions of the area. Confidence of storm initiation and severe-level impacts continues to dwindle.

DISCUSSION

As of 230 PM EDT Wednesday...

KEY MESSAGE 1...A strong cold front crosses the area Thursday morning-midday, bringing a very good chance of rain, along with a low-end potential for some stronger storms during the first part of Thursday. A few snowflakes may mix in Thursday afternoon but no accumulation is expected. Cooler temperatures and dry weather return to end the week.

A southern stream low pressure system along a cold front tracks across the Gulf today before moving into the Carolinas Thursday. The vast majority of the precipitation associated with the front is progged to fall behind the front with the best precip chances from late morning-early evening as that southern stream system tracks just to our south.

Temperatures will likely warm a couple degrees across SE VA/NE NC Thurs AM before the cold front moves through. However, as the front crosses SE VA/NE NC between 9 AM-1 PM Thursday, some destabilization is possible ahead of the frontal boundary with the onset of daytime heating (temps warm into the mid 70s). This could lead to the development of a narrow line of gusty showers just ahead of the front, which could easily bring ~40 mph gusts. However, confidence in gusts approaching severe levels (50 kt) remains very low at this time. Regardless of any convection, a few hours worth of 30-40 mph gusts are likely across much of the area as winds become NW right behind the front. Temps are expected to drop from around 70F to the 40s very quickly following the FROPA. Some areas will likely drop into the mid-upper 30s Thu aftn as the precip moves through. Did go ahead and add a brief period of snow/rain mix to the evening hours. However, no accumulation is expected given warm antecedent condition and marginal temperatures. Would need very strong rates to achieve accumulations, which are not very likely on the back end of this system. With the strong front coming through, high temperatures shown in the forecast are likely to be achieved early in the day, with rapidly falling temps through the day.

Looking through the extended, seasonably cooler and dry weather returns Friday, with highs dropping back into the 50s despite plentiful sunshine. Milder conditions with temps approaching 70 F are forecasted by the weekend as transient high pressure slides over, also supporting continued mainly dry wx. Another low pressure system and cold front brings a good chance of showers (with perhaps an isolated tstm) to the area on Monday.

KEY MESSAGE 2...There is a low-end chance (15-25%) of isolated showers/thunderstorms across the extreme northern portions of the area. Confidence of storm initiation and severe-level impacts continues to dwindle.

Latest mesoanalysis indicates that CAPE is climbing with an area of 500+ J/kg climbing north. However, the area is still strongly capped and high level cloud cover is situated over much of the area. It does not appear that the forcing will be strong enough to break the cap this far south with the better dynamics to the north closer to the sfc low over the Great Lakes and the stronger UL flow to the NW. The CAMs have largely backed off of convection as well. As a result, the SPC did downgrade the outlook for the FA with the marginal now barely clipping the northern counties. If a storm does manage to initiate, there is a chance for damaging winds and quarter sized hail.

AVIATION /00Z THURSDAY THROUGH MONDAY/

As of 800 PM EDT Wednesday...

VFR conditions are expected throughout the night. Winds will remain gusty out of the S to SW and LLWS is possible at all sites overnight. Attention then turns to a strong cold front set to cross the area through the day tomorrow. This will bring MVFR CIGs, widespread rain, and gusty winds. Could see a few rumbles of thunder in the morning in the southeast. IFR CIGs are also possible at RIC ~18z, potentially spreading into PHF as well. A quick drop in temperatures will bring a brief changeover to snow starting around 18z at RIC and SBY and ~20-22z at the SE TAF sites. Periods of IFR VSBYs are likely with any heavier RASN or SN. SW winds quickly change to the NW behind the front with gusts of 25-30 knots possible.

Outlook: VFR conditions return Thursday night and persist into Saturday.

MARINE

As of 305 PM EDT Wednesday...

- Small Craft Advisories are in effect for the Chesapeake Bay, tidal rivers, and northern coastal waters from this evening into Thursday, and for the Currituck sound for Thursday.

- Gale Warnings are now in effect for the Ocean from Cape Charles to Currituck Beach Light NC, and for the mouth of the Chesapeake Bay on Thursday.

Low pressure is noted near the eastern Great Lakes this aftn, and expect to continue to see a tightening the pressure gradient over the local waters. The very warm airmass over cold waters has kept mixing limited so thus far, winds have been S-SW at 10-15 kt with just a few gusts to ~ 20kt. SSW/SW winds could eventually increase to 15-20 kt with gusts to 25 kt this evening into the overnight hours. SCA headlines are in effect starting this evening/tonight for the Ches Bay, rivers, and Atlantic coastal waters north of Cape Charles Light, lasting through early Thursday evening. 12z guidance timing is similar to last night's 00Z data regarding the strong cold front crossing the waters. Still expect this very strong front to be near the northern waters by sunrise Thursday and be south of the area by early Thursday afternoon. The Gale Watches for the mouth of the Bay and the Ocean S of Cape Charles have been upgraded to Gale Warnings with this forecast package, given impressive pressure rises (9-12mb in 6 hours) immediately behind the cold front and winds could gust aoa 35 kt as the boundary comes through. It still appears that the best chance for prolonged gusts in this range will be focused across the southern third of the area from mid morning through mid afternoon. This includes the mouth of the bay and Atlantic coastal waters south of Cape Charles Light. Elsewhere, the period of post-frontal 30-40 kt gusts will be shorter and will likely be handled with short-fuse SMWs as needed (this has been mentioned in the MWW). The gradient begins to relax Thursday afternoon and especially during the evening and overnight hours.

Seas will build to 4-6 ft far N and 3-4 ft S in the pre-frontal SW flow tonight, On Thu, seas will avg 4-5 ft N, and will build to 5-7 ft S (where the strongest winds will occur). Waves in the Chesapeake Bay will increase to 2-4 ft ahead of the front and reach to 3-5 ft through much of Thursday during the stronger NNW winds. Another system moves by well to the north on Friday with potential for another period of SCA conditions, as increasing S to SW winds develop.

CLIMATE

As of 800 PM EDT Wednesday...

Record highs were set at ORF (88F), RIC (89F), SBY (86F), and ECG (86F) today. Record high mins will also likely be set today.

- Record High Min Temps for today (3/11)

Location Rec High Min -------- ------------ - Richmond 56 (1955) - Norfolk 62 (1925) - Salisbury 51 (1955) - Eliz. City 58 (1967)

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 7 PM EDT Thursday for ANZ630>632- 638-650-652-654. Small Craft Advisory from 10 AM to 7 PM EDT Thursday for ANZ633. Small Craft Advisory until 10 AM EDT Thursday for ANZ634. Gale Warning from 10 AM to 4 PM EDT Thursday for ANZ634. Small Craft Advisory until 7 PM EDT Thursday for ANZ635>637. Gale Warning from 10 AM to 7 PM EDT Thursday for ANZ656-658.