textproduct: Wakefield

WHAT HAS CHANGED

The forecast remains on track this afternoon. There is a marginal risk of severe weather through this evening, followed by a slightly drier and seasonable day for Saturday. Heat and humidity, as well as increasing shower/storm chances return Sunday and Monday.

KEY MESSAGES

1) A wave of low pressure along a weakening frontal boundary brings scattered showers and storms to the area this afternoon into tonight. There is a Marginal Risk of severe storms across much of the forecast area this afternoon.

2) Seasonable on Saturday, becoming more unsettled again for Sunday.

3) Hot and humid with afternoon storms Monday ahead of the next cold front.

DISCUSSION

As of 245 PM EDT Friday...

KEY MESSAGE 1...A wave of low pressure along a weakening frontal boundary brings scattered showers and storms to the area this afternoon into tonight. There is a Marginal Risk of severe storms across much of the forecast area this afternoon.

This afternoon, a weak, diffuse frontal boundary is located from roughly central VA over to the Middle Peninsula. South of the boundary, a very hot and humid airmass is in place with temperatures ranging from the upper 80s to mid 90s and dewpoints in the mid to upper 70s. The hot temperatures combined with the high humidity have allowed for heat index values to climb to ~100 to 105 degrees, with readings of 105+ across northeast North Carolina where a Heat Advisory remains in effect until 7 PM.

Convective initiation has started along and just north of the boundary where we have already seen a couple of severe storms, one near Newport News and one just south of Salisbury, MD. Strong diurnal heating has destabilized the airmass, with MLCAPE values ~2000-3000 J/kg south of the boundary. Deep-layer shear is fairly weak along and south of the boundary (~20 to 25 knots) and strongest across the far northeast (~35 to 40 knots). Expect mainly pulse activity with potentially a few bowing segments as we head through the afternoon/evening. Damaging wind gusts of 50 to 60 mph are possible with the strongest storms. SPC has a majority of the area in a Marginal (1 out of 5 risk) for severe storms this afternoon. In addition, high moisture content (PWATs 2.0+") will yield high rain rates and local urban or poor drainage flooding. Any storms push SSE into North Carolina this evening before gradually tapering off after ~02z (10 PM).

KEY MESSAGE 2...Seasonable on Saturday, becoming more unsettled again for Sunday.

Surface high pressure north of the Great Lakes ridges south into the Mid-Atlantic on Saturday, pushing the surface boundary off to our S/SW. Light E-NE flow will usher in a slightly drier and more seasonable airmass with highs in the upper 80s. Most areas stay dry on Saturday, but isolated to scattered showers/storms will be possible in the afternoon, especially near the NC border. On Sunday, the expansive ridge over the Southern US begins to break down as a trough digs over the Midwest. Return southerly flow brings the heat and tropical moisture back into the region. Scattered to widespread afternoon/evening thunderstorms return for Sunday. Thunderstorms will again have the potential to produce strong to severe wind gusts, with SPC placing the entire forecast area in a Day 3 Marginal (1 out of 5) risk for severe storms. Locally heavy rainfall will also be possible with any of these storms and isolated instances of flooding, especially in urban or poor drainage areas, will be possible.

KEY MESSAGE 3...Hot and humid with afternoon storms Monday ahead of the next cold front.

Hot, humid conditions likely peak on Monday ahead of an approaching cold front. Highs in the low to mid 90s, combined with elevated humidity will likely necessitate additional Heat Advisories for at least our southern/southeastern counties. Scattered showers and storms are also expected Monday afternoon/evening along the frontal boundary. Drier and slightly cooler conditions arrive Tuesday into midweek.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

As of 150 PM EDT Friday...

Early this afternoon, a weak surface boundary stretches from central Virginia over to the Middle Peninsula. Showers and thunderstorms have started to develop along and north of the boundary this afternoon, with the strongest storm currently just south of PHF. Any storms will have the potential to produce gusty winds and brief IFR VSBY restrictions. Outside of storms, VFR conditions prevail this afternoon. Surface winds ahead of the boundary are light out of the W/SW ~5 to 10 knots, shifting to the WNW/N behind the boundary. Scattered showers and storms will continue to build in coverage across the area this afternoon and gradually progress S/SE. Activity gradual tapers off from north to south after sunrise, eventually moving south of the area overnight. Localized MVFR/IFR stratus and/or ground fog may develop later tonight into the early morning hours of Saturday, but confidence is low. Quieter conditions return on Saturday, with most of the shower activity west of the main terminals.

Outlook: Scattered aftn/evening showers/storms are possible Sunday through Monday bringing the potential for occasional sub-VFR conditions. Lower shower/storm chances Tuesday through Wednesday.

MARINE

As of 245 PM EDT Friday...

Key Message:

- Sub-SCA marine conditions are expected to prevail through the upcoming weekend.

- Marginal Small Craft Advisory conditions could develop as southerly flow increases early Monday morning.

Generally benign conditions in place this afternoon. Surface analysis places a weak stationary boundary and low pressure system near the waters and these features will focus showers and storms for portions of the local area this afternoon and evening. Locally higher winds and waves would be expected in any storm core.

Sub-SCA conditions are expected to prevail through most of the weekend. The boundary drops south tonight with a NE wind direction developing and persisting through most of Saturday. Wind speeds will generally be 10-12 kt with gusts upwards of 15 kt or so. Seas bump up closer to 3 ft Saturday, but remain well below any SCA thresholds. Winds become easterly Saturday night and then S-SE Sunday. A period of elevated winds is possible in the southerly flow period later Sunday night into Monday morning, though again, likely remaining predominately sub-SCA. Still, a brief period of low-end SCA gusts cannot be completely ruled out for late Sun night/early Monday morning. Thereafter, light flow (10 kt or less) is generally favored Monday through the middle of next week.

Rip Currents: A low rip current risk continues today. NE flow and choppy surf conditions could allow for a moderate risk on Saturday, but it really depends on the height of the nearshore waves.The northern beaches could then also approach "moderate" Sunday as southerly flow increases.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...Heat Advisory until 7 PM EDT this evening for NCZ015-030>032. VA...None. MARINE...None.