textproduct: Wakefield

WHAT HAS CHANGED

Marginal Risk for strong to severe storms across the northern half of the area today with a Slight Risk over most of the region on Thursday.

KEY MESSAGES

1) A bit warmer and more humid today with scattered showers/storms possible.

2) Hot and humid Thursday-Friday, along with the chance for isolated to scattered showers and storms.

3) A cold front crosses the area early Saturday, bringing drier, and somewhat cooler temperatures to the region.

DISCUSSION

As of 305 AM EDT Wednesday...

KEY MESSAGE 1...A bit warmer and more humid today with scattered showers/storms possible.

High pressure remains centered well off the Southeast coast early this morning. Aloft, ridging will persist across the Gulf Coast eastward into the SE CONUS. A belt of stronger westerly flow will continue across the northern half of the area today, which will allow clouds and showers from decaying convection over the Midwest to creep into western portions of the area this morning. This potential complicates the temperature forecast as well as the possibility of renewed convective development later this afternoon. The latest guidance has trended toward weakening showers moving into the Piedmont around sunrise with associated clouds moving east and thinning by the afternoon hours. If a period of moderate to strong heating is realized, additional showers and thunderstorms are possible, mainly across the northern half of the area by mid to late afternoon into the evening. Some of these cells could be strong if enough instability is able to materialize with gusty winds the main threat. Given the above considerations, decided to knock a few degrees off the blended temperature guidance this afternoon, resulting in high temps in the mid to upper 80s (highest S where any potential showers/storms will not arrive until well after peak heating). Showers and storms linger near the coast late this evening with lows only falling into the low 70s overnight.

KEY MESSAGE 2...Hot and humid Thursday-Friday, along with the chance for isolated to scattered showers and storms.

Surface high pressure anchors offshore as an upper ridge builds across the Southeast Thu-Fri. The upper ridge will be centered south of the local area with stronger flow aloft impinging on the Mid- Atlantic, allowing for the potential for upper level disturbances to traverse the region and spark mainly diurnal chances for showers and storms. SPC has introduced a large Slight Risk (level 2/5) for strong to severe storms over most of the region on Thursday. Guidance shows a shortwave aloft translating eastward to our north on Thursday. A lee surface trough will also be in place across the region Thursday afternoon. Forecast soundings show decently steep mid level lapse rates for this part of the country along with ample low level moisture. Deep layer shear appears to be the limiting factor for most of the area on Thursday but some robust pulse-type cells with gusty winds are certainly possible given the thermodynamic environment. Somewhat stronger shear is progged across the northern third of the CWA where the potential exists for more organized convective structures.

The upper ridge amplifies to our south Thursday and Friday with neutral or slowly rising heights aloft. High temperatures likely rise into the mid and upper 90s each afternoon but cloud cover and continued chances for showers and storms lend some lingering uncertainty to the temperature forecast. Low level moisture is expected to tick up late this week which will result in the potential for heat index values to rise mainly into the 100-105 range Thursday and Friday, depending on coverage and timing of any convection or thicker cloud cover. Heat Advisories may be needed for at least some of the region. At this time, Friday has a slightly better chance for seeing dew pts mix down into the 60s across inland areas during peak heating hours. Additional showers and potential for strong storms continues Friday afternoon and evening as upper heights fall ahead of the next cold front approaching from the N.

KEY MESSAGE 3...A cold front crosses the area early Saturday, bringing drier, and somewhat cooler temperatures to the region.

Latest guidance continues to depict the upper level ridge breaking down Friday night into the weekend as a strong upper trough/low gradually drifts E-SE from northern Ontario towards the St Lawrence Valley. While the airmass in the wake of the front will remain warm, the wind shift to N-NE should lead to cooler conditions Saturday, especially at the coast, along with lower dew pts area-wide. ECMWF ensemble and GEFS show the PWAT anomalies dropping to below normal before a modest return flow starts late Sunday into Monday ahead of another front. Latest guidance has backed off on the potential for showers or storms across the region on Saturday. Southerly winds return on Sunday with increasing low level moisture and the chance for diurnal showers and storms continuing into early next week.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

As of 700 AM EDT Wednesday...

VFR conditions continue to be favored though BKN-OVC high clouds persist this morning. Some potential still exists for lowering CIGs as a batch of showers move in from the W over the next few hours. Model guidance varies with the placement of these lower clouds (and showers), but marginal MVFR is possible in the northern Piedmont and potentially near RIC and SBY in the 12-17z timeframe. Morning showers are favored at RIC and SBY before a lull arrives in the early afternoon. Otherwise, mainly VFR is expected this afternoon and evening, though another round of showers, with a better chance of storms, is possible in the late afternoon and evening. Have PROB30 groups at SBY, RIC, ORF, and PHF for locally reduced VSBY and CIGs, generally after 20z. Winds average 5-10 kt out of the S this morning, shifting to the SW with gusts to ~20 kt.

Outlook...Mainly VFR conditions Thu-Fri, but with a chc of mainly diurnal showers/tstms. A few stronger storms are also possible. A weakening cold front slowly approaches from the NW Friday and Saturday with a chc of mainly diurnal showers/tstms continuing SE (with lower coverage to the N for the weekend).

MARINE

As of 245 AM EDT Wednesday...

Key Messages:

- A period of elevated southerly flow continues into tonight. Small Craft Advisories have been issued for all coastal waters from late this afternoon into tonight.

- Another period of elevated southerly winds is possible late Sunday into Sunday night.

- There is a moderate risk for rip currents today across all area beaches.

Latest surface analysis depicted high pressure offshore with S winds 10-15 kt with gusts up to 20 kt. Winds increase to 15-20 kt with gusts up to 25-30 kt across the coastal waters late this afternoon into tonight, becoming SW late. This will allow for seas to build to 4-5 ft across the coastal waters. As such, SCAs have been expanded to include all of the coastal waters. However, will note that SCA conditions appear to be more marginal across the coastal waters south of Cape Charles Light. While a brief increase in SW winds to 15-17 kt with gusts up to 20 kt is possible across the Lower Ches Bay this evening into tonight, confidence in sustained 18 kt winds and SCA conditions remains too low for SCAs at this time (winds probs for 18 kt sustained winds were only 20-25%). Winds and seas diminish Thu with generally benign marine conditions (outside of any convection) likely from Thu into Sun. Another period of elevated S winds is possible from late Sun into Sun night.

There is a moderate risk for rip currents today across all area beaches.

CLIMATE

Record High Temperatures:

- Date: Thu 6/11 Fri 6/12

- ORF: 98 (1911) 99 (1986) - RIC: 97 (1984) 100 (1914) - SBY: 96 (1914) 98 (1914) - ECG: 99 (1947) 97 (1947)

Record High Min Temperatures:

- Date: Thu 6/11 Fri 6/12

- ORF: 75 (2020) 76 (2016) - RIC: 75 (1914) 74 (1986) - SBY: 73 (2013) 75 (1947) - ECG: 75 (2020) 76 (2016)

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 4 PM this afternoon to 4 AM EDT Thursday for ANZ650-652-654-656-658.