textproduct: Wakefield

WHAT HAS CHANGED

Updated aviation discussion.

KEY MESSAGES

1) Scattered showers and storms are expected today and Saturday. Some storms may be severe with damaging wind gusts and isolated large hail possible.

2) Hot and humid conditions continue today with Heat Advisories in effect for portions of central and SE VA as well as NE NC along and east of I-95.

DISCUSSION

As of 400 AM EDT Friday...

KEY MESSAGE 1...Scattered showers and storms are expected today and Saturday. Some storms may be severe with damaging wind gusts and isolated large hail possible.

Aloft, the ridge remains in place today from the Great Lakes into the Southeast with a trough across SE Canada into New England. The trough slides farther south today while the ridge become more amplified into the Northern Plains. As such, the belt of NW flow aloft shifts a bit south over the local area. This will place the entire local area under the favorable corridor for storms which stretches from the southern Great Lakes and Ohio SE into VA. Will note that clusters of storms have already formed across Wisconsin (E and NW). These storm complexes may continue to follow the NW flow and approach the local area later this afternoon into this evening. As is typical in NW flow MCS patterns, CAMs may not have a good handle on how long this convection persists and especially whether or not it can survive crossing the mountains. As such, will need to monitor the mesoscale environment as well as satellite and radar trends through the day to get a better idea as to whether or not the convection looks like it can make it here.

With falling upper heights and the approaching front, scattered to potentially numerous storms are expected to develop during the afternoon and spread southeast through the evening. Given the overall favorable severe parameters of adequate CAPE and 0-6km shear of 30-45 kt, any storms that do form have the potential to become severe with damaging winds and isolated large hail the primary hazards. DCAPE will likely also be high, further supporting the damaging wind potential. The lack of low level shear and generally high LCLs will likely limit any tornado threat. Given the favorable synoptic setup, SPC has maintained the Slight Risk (Level 2 out of 5) for severe weather across the entire area today. Convection should taper off this evening, however, SPC does note the potential for an overnight round of convection moving into WV which may need to be watched in case it can make it across the mountains.

By Sat, the trough builds closer to the local area, pushing a cold front slowly through. However, recent trends have been for a slower FROPA with the front potentially stalling just south of the FA. As it stands, the current forecast maintains N/NNW winds Sat afternoon which is generally unfavorable for severe weather. Nevertheless, a sufficient overlap of CAPE and shear will likely remain across the FA with higher instability across southern portions of the area. As such, forcing from another shortwave embedded within the NW flow aloft should be enough for at least scattered showers and storms Sat afternoon into Sat evening with the best chance across the SW/S portions of the area. SPC has a Marginal risk for severe storms Sat generally along and south of I-64 with a Slight risk across NE NC and extreme S VA. The main threat will once again be damaging winds, although, isolated large hail is also possible if more discrete convection/supercells are able to form.

Severe weather will not be the only potential hazard. WPC has placed the entire FA under a Marginal Risk for Excessive Rainfall (ERO) today with most of the area (apart from portions of the Northern Neck and Eastern Shore) under a Marginal Risk again on Sat. In fact, WPC has even placed a small Slight ERO across extreme SE VA and NE NC Sat (including portions of the Hampton Roads) given the potential for heavy rain and localized flooding. Fortunately, given the shear in place, individual showers/storms should be moving both days which should help limit the flooding potential outside of training. Shower/storm chances decrease Sun (15-40% PoPs) to mainly the SW half of the FA. Beyond Sun, dry conditions are expected for early next week.

KEY MESSAGE 2...Hot and humid conditions continue today with Heat Advisories in effect for portions of central and SE VA as well as NE NC along and east of I-95.

With the ridge remaining in place today and the cold front well to the north, another hot and humid day is expected. Highs this afternoon will likely reach the upper 90s SW with potentially only lower 90s NE. Meanwhile, dew points likely remain generally in the low-mid 70s apart from the SW Piedmont where mixing may allow for locally upper 60s dew points. This will allow for yet another day with heat indices at or above 100F for most of the area. The hottest conditions look to be across portions of central VA and SE VA into NE NC where heat indices of 105-109F are possible. As such, have kept Heat Advisories in place for these areas. Farther to the north into the Northern Neck, confidence is lower in reaching above 105F heat indices given the potential for lingering stability from the MCS that moved through overnight. As of the writing of this discussion, the outflow boundary from the MCS has made it nearly to Wakefield which may result in temps and/or dew points underperforming slightly across central VA. Additionally, scattered afternoon convection and cloud cover lowers confidence as well. Given the uncertainties in how the over-churned airmass will affect mixing today, have decided to not make any changes to the Heat Advisories at this time.

The trough moves into the area by Sat with a cold front slowly pushing south across the local area. This will allow for cooler conditions this weekend into at least early next week with highs in the mid 80s NE to the low-mid 90s SW Sat and low-mid 80s Sun into Mon. The ridge potentially builds back in at least briefly by the middle to later part of next week, however, confidence is low at this time given a plethora of shortwaves between now and then.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

As of 630 AM EDT Friday...

VFR conditions prevail for the terminals this morning. A few lingering SHRA will depart SBY within the next hour or two. W/NW winds will be AOB 10 kts through the TAF period. Thunderstorm chances will increase again after 04/19Z, though confidence in exact coverage is low. Currently only have a PROB30 in for ECG after 21Z since guidance continues to indicate slightly higher confidence further south. Once again, gusty, erratic winds and VIS restrictions from +RA will be likely in any storm that develops. Storm coverage should decrease overnight, but can't rule out lingering activity for SBY again. A stronger cold front will approach from the north overnight, turning winds more northerly towards the end of the TAF period.

Outlook: Storm chances continue on Saturday, with the highest PoPs S and SW of RIC. Mainly dry/VFR Sunday through Tuesday behind the front, though brief MVFR CIGs are possible near the coast with NE flow.

MARINE

As of 300 AM EDT Friday...

Key Messages:

- Cold front pushes through Friday night into Saturday morning turning winds north/northeasterly. Evening thunderstorm chances continue with gusty winds possible.

- Northeasterly winds and seas will increase Sunday into Monday as high pressure builds in from the north, potentially warranting Small Craft Advisories.

South/southwesterly winds have become 10-15kt with gusts to 20kt early this morning as expected. Guidance continues to show winds diminishing towards daybreak. Thunderstorms with gusty winds will move across the upper Bay and northern coastal waters for the next couple of hours before chances come to an end. Winds will remain light during the day today with seas of 2-3ft and waves in the Bay of 1-2ft. Another chance for storms with gusty winds is possible later this evening. A cold front will approach from the north tonight and start to turn winds northerly. Winds look to increase to 10-15kt as the front pushes through into Saturday morning, but currently expecting sub-SCA conditions to persist. Northeasterly winds subside later Saturday.

High pressure will build into the area from the north on Sunday increasing the pressure gradient over the local area. This will result in northeasterly winds becoming 15-20kt Sunday into Monday. Seas will also build to 4-5ft across the north and 5-6ft for the south, with the higher seas further offshore. Waves in the mouth of the Bay will increase to 3ft as well. A SCA may be needed to cover this for portions of Sunday and Monday. More benign marine conditions look to return later Monday into Tuesday as winds and seas both subside.

There is a Low Rip Current Risk today and Saturday for all beaches. Rip Risk becomes Moderate on Sunday as onshore winds and waves build.

CLIMATE

No records were set on Thursday, 9/3 at any of the climate sites. Record highs will be approached today (Friday, 9/4) at a few sites.

Richmond: Record High:

Fri (9/4) 98/2023

Norfolk: Record High: Fri (9/4) 96/1985

Salisbury: Record High: Fri (9/4) 95/1944

Elizabeth City: Record High: Fri (9/4) 98/1944

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for NCZ012>017-030>032-102. VA...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for VAZ080>090-092-097-098-511>520-523>525-528>531. MARINE...None.