textproduct: Wakefield

WHAT HAS CHANGED

Marginal risk of severe weather continues this afternoon and for tomorrow.

KEY MESSAGES

1) Showers and thunderstorms continue through the evening potentially producing a strong to severe wind gust.

2) Showers and Thunderstorms chances continue for Saturday with seasonable temperatures.

3) Slightly below temps are possible through the first half of the week before warmer temperatures potentially return by the end of the week.

DISCUSSION

As of 327 PM EDT Friday...

KEY MESSAGE 1...Showers and thunderstorms continue through the evening potentially producing a strong to severe wind gust. .

Afternoon weather analysis shows multiple 700mb shortwaves moving across the area. These waves have helped initiate showers and storms across the Piedmont along a Lee-trough. The environment for these storms remains quite weak. With downsloping winds occuring today it has caused dew points to mix into the upper 60s to low 70s (primarily across the far SE. However, with adequate day time heating it has allowed temps to rise into the upper 80s to low 90s creating enough DCape (1000-1300J/kg) to where if any storm is able to become mature could pose the risk of a strong to severe wind gust. Through the evening storms are progged to continue tracking primarily along and south of I-64 before dying out by late this evening when daytime heating is lost and storms lose their energy. By tonight, the storms will have lost their energy and the severe threat will have diminished but models continue to hint on multiple showers across the east tonight so decided to add a slight chance of POPs 15-20%. Otherwise, temperatures tonight will be in the upper 60s to low 70s inland and middle 70s across the far SE.

KEY MESSAGE 2...Showers and Thunderstorms chances continue for Saturday with seasonable temperatures.

A stronger cold front is progged to move through the area Saturday. With a stronger surface forcing this may provide better chances for a higher coverage in showers and thunderstorms. However, there still remains the question of the severity of the storms. Both the shear and instability look meager. Guidance continues to just enough bulk- shear 25-35kt to where storms could maintain themselves. In addition, as the sub-tropical airmass is in place dews are progged to be in the low 70s and day time temps to be in upper 80s to low 90s this should allow ML cape to build between 1000-1500J/kg. This is just enough atmosphere ingredients for any storm to become mature to poise the risk of a strong to severe wind gust. Will also mention there is a risk for flash flooding given PWATS ~2". However, the flash flooding will be very isolated in nature given storm motions are slight too fast and models having disagreement on storm convergence. By Saturday evening storms will diminish as energy is lost.

KEY MESSAGE 3... Slightly below temps are possible through the first half of the week before warmer temperatures potentially return by the end of the week.

Models continue to show a drier pattern returning to the area by the Sunday as high pressure returns to the region. The majority of the are will remain dry. However, there is a chance of showers and storms across the south as models do hint on a cut-off low across the southern Appalachians that may help fire storms. By the afternoon Sunday the high will usher in slightly below temperatures with highs nearing the low 80s and lows in the low to middle 60s. By the middle of next week, the recent ensemble guidance shows an upper ridge building over the upper Midwest and pivoting into the Mid- Atlantic. This will potentially allow temps to bounce back into the upper 80s to low 90s. In terms of rain chances, they remain quite low next week as models hint on a drier pattern.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

As of 800 PM EDT Friday...

VFR conditions prevail for the 00z/11 TAFs. Scattered light rain showers linger across the eastern half of the area, but am not anticipating any flight restrictions with this activity. The strongest thunderstorms will remain south of the TAF sites this evening-overnight. Mid to high level clouds will prevail throughout the sites tonight into Saturday morning. By Saturday afternoon and evening, another round of additional scattered showers/storms is once again possible. PROB30 groups have been introduced at RIC and SBY for later Saturday afternoon. Showers/storms may hold off until the evening for the southeastern TAF sites.

Outlook: Another round of afternoon showers/storms is possible Sunday. Trending drier Monday into the middle of next week. Predominately VFR conditions are expected outside of any thunderstorms.

MARINE

As of 250 PM EDT Friday...

Key Messages...

- Elevated onshore flow develops Sunday into Monday with Small Craft Advisory conditions possible.

- There is a moderate risk for rip currents today across all area beaches and only across the northern beaches on Saturday.

- Tidal anomalies increase into early next week with widespread nuisance to minor flooding possible by the Sunday night high tide.

Winds were generally W/S 5-10 kt early this afternoon. Winds are expected to become S/SE late this afternoon with the sea/bay breeze, becoming SW once again tonight with the land breeze. SW winds increase to 10-15 kt overnight before diminishing Sat as a cold front approaches from the north. A cold front crosses the local waters from late Sat morning through Sat afternoon, allowing winds to become N behind the front. Winds gradually become NNE 10-15 kt Sat night. High pressure builds in from the north behind the front early next week. As it does so, the pressure gradient between the high to the north and a weak surface low along a stationary front to the south should allow for a strong enough pressure gradient for a prolonged period of elevated onshore flow from Sun through Mon. During this time, NE/ENE winds of 15-20 kt with gusts up to 25 kt are increasingly likely. Additionally, seas build to 4-6 ft (highest across the NC coastal waters) with 3-4 ft waves possible across the lower Ches Bay. As such, SCAs will likely be needed for at least a portion of the local waters. Winds diminish Mon night as the high builds in with generally benign marine conditions returning.

Rip Currents: A moderate risk for rip currents continues today across the local waters. However, will note that the rip current threat is lower across the southern beaches than the northern beaches. For Sat, have maintained a moderate risk for rip currents across the northern beaches and have a low risk across the southern beaches. This fits the distribution of rip currents reported from lifeguards over the past couple of days. Additionally, the period remains higher in the morning around low tide (8-9 seconds) across the northern beaches. By Sun, winds become elevated and onshore, lingering into Mon. However, periods are modeled to be low on Sun (~5 seconds) with periods increasing to 7-8 seconds on Mon. As such, have a moderate rip current risk everywhere on Sun and a high rip current risk across the southern beaches on Mon (moderate north).

Coastal Flooding: Tidal anomalies increase into early next week as we head into a period of King Tides. This will allow for the higher of each daily high tide (the evening high tide) to rise into action or minor flood stage each day over the next several days. Tonight is the lower tide with mainly nuisance flooding expected (locally minor at Bishops Head) across the middle Ches Bay. By Sun night, elevated NE/E winds combined with the higher tidal anomalies should allow for widespread nuisance to minor coastal flooding across the Ches Bay and local rivers and perhaps even at Duck.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...None.