textproduct: Wakefield

WHAT HAS CHANGED

Delayed the onset of showers and storms moving into the piedmont this afternoon.

KEY MESSAGES

1) Showers and storms return this evening, with some storms potentially becoming strong to severe.

2) A more summer-like pattern takes hold Wednesday night into the weekend.

DISCUSSION

As of 235 AM EDT Monday...

KEY MESSAGE 1...Showers and storms return this evening, with some storms potentially becoming strong to severe.

A warm front is lifting through the area this morning, with winds becoming southerly and dew points increasing in its wake. Temperatures have struggled to drop lower than the upper 60s to lower 70s, making for a warmer late June morning. Despite the increasing moisture, the local radar remains echo-free, with any forcing mechanism still well to our west/northwest.

Winds will become quite breezy today as the gradient tightens between an approaching low and high pressure to our SE. Gusts of 20- 25 mph (25-30 mph on the Eastern Shore) are forecast during the afternoon. Today's convective forecast is turning out to be a little tricky due to an upstream MCS moving across the Ohio River Valley. This convection continues to track eastward overnight, despite the typically unfavorable overnight environment. If this feature can continue to push eastwards over the next few hours, cloud debris could keep temperatures a few degrees cooler and could also potentially push a more stable environment into our northern and western counties this morning. This could delay the erosion of the cap or even prematurely force early convective initiation along and remnant boundaries. If this does occur, the environment may become worked over which could inhibit much in the way of severe storms as we saw with the system last week. With some evolving uncertainty regarding the timing and coverage of any developing convection today, have decided to delay the onset of convection, with storms starting to enter the piedmont by mid-late afternoon and slowly pushing through the area through the late evening into the overnight hours.

SPC has maintained a Slight Risk (level 2/5) for severe weather for most of the area today, with damaging wind gusts being the main threat. Any tornado threat will be co-located with where the warm front, which will likely be north of our area. In terms of storm mode, multicellular storms and bowing line segments are favored at this time. Deep-layer bulk shear is not expected to be overly strong, ranging from ~25-35 kt across the far north, tapering to ~20 kt south of Interstate 64. However, low-level lapse rates will again be quite steep due to very warm surface temperatures, favoring the potential for cold-pool dominated storms with water-loaded downdrafts. Additionally, PWAT values increase to 1.75-2.25" through the day, leading to the potential for locally heavy rainfall. Widespread flooding issues are certainly not expected given very dry antecedent conditions and fast motion of the storms, but we will need to monitor urban and typical poor-drainage areas. The shower and storm threat will continue through the early overnight hours before tapering off. Due to the later expected start for convection, the SE areas may be limited as the environment becomes less favorable with the loss of daytime heating.

KEY MESSAGE 2...A more summer-like pattern takes hold Wednesday night into the weekend.

The front will move through the area on Tuesday, though it will take its time. This will allow at least SE/S VA and NE NC to warm up into the upper 80s with dew points in the upper 60s to lower 70s. Most guidance is still suggesting that there will be some instability across the area, especially near the coast, to support some shower and thunderstorm development in the afternoon/evening hours. If the front moves quicker, then these storms will struggle to develop, but with very good model consensus, have kept likely rain chances for the SE portion of the forecast area Tuesday afternoon/evening. After the front moves through, a drier airmass will replace the current muggy airmass, which will keep Wednesday dry and less humid. Even with the slightly cooler airmass, temperatures will still reach near- normal for this time of year, peaking in the mid to upper 80s. By Wednesday night, winds will quickly shift back to the SE-S and bring back normal June humidity amd temperatures. For the remainder of the week, a more typical summertime pattern sets up for late week. Mainly seasonable temperatures are expected, with diurnally driven, scattered late-day and evening showers and storms possible each day. Expect highs mainly in the upper 80s and low 90s, with overnight lows in the 60s to near 70.

AVIATION /06Z MONDAY THROUGH FRIDAY/

As of 130 AM EDT Monday...

VFR conditions will prevail through this afternoon/early evening at all terminals. Southwest winds will start to pick up by mid-morning, with gusts of 20-25 kt likely through the afternoon. There is some uncertainty regarding the arrival time of any convection today evening, so have just included PROB30 at RIC and SBY. Uncertainty increases for the SE terminals (not including ECG), so have just decided to include VCSH for when showers may start nearing the terminals late in the period. If confidence increases with the next TAF update, will include a PROB30 for the southern terminals. Winds will start to relax after sunset, but will remain southerly until the front moves through on Tuesday.

Outlook: Decent chc for periodic flight restrictions for some patchy low stratus or fog early Tuesday where it rains this evening. Mainly VFR during the day Tuesday, but with additional diurnally-driven late day/evening tstms possible. Mainly dry/VFR Wed. Additional late day showers/storms possible Thu- Fri.

MARINE

As of 235 AM EDT Monday...

Key Messages:

- S-SE winds strengthen today ahead of the next system. Small Craft Advisories remain in effect for all marine zones north of the VA/NC border from today through part of tonight.

- Benign, sub-SCA conditions are expected for much of the rest of the week.

Winds have become S at around 10 kt well in advance of a low pressure system tracking now just east of the mid-Mississippi River Valley. This low is progged to continue tracking ENE and pass by just to our north Tuesday morning. The low will drag a warm front well north of the waters today. Also, the pressure gradient will tighten ahead of the approaching low. As a result, southerly winds will increase to 15-20 kt on the rivers, and 20-25 kt across part of the bay and the offshore waters north of the VA-NC border (with gusts to 30 kt) during the day today. Winds will be a few knots less across the NC waters. Wind speeds will peak late this afternoon into the early evening before veering to the SW and diminishing to ~15 kt by early Tuesday morning. Seas will build to 3-4 ft south/4-6 ft north. Small Craft Advisories remain in effect for all marine zones north of the VA/NC border from late this morning through tonight.

Additionally, isolated strong to severe storms are possible this evening, which will likely necessitate SMWs. As the low tracks to our north, a weak cold front will cross the waters on Tuesday. Winds shift to the NW by late Tuesday afternoon/Tuesday evening behind the front, and may increase slightly Tuesday night. There are varying solutions with respect to wind speed behind the front, and while forecast wind speeds are no higher than 15 kt, a brief period of low- end SCAs can't be ruled out on the bay late Tue-Tue night. Local wind probs for sustained 18 kt winds peak between 10-25% on the bay Tue evening/night. Prevailing sub-SCA conditions are expected the rest of the week as high pressure returns.

The rip current risk increases to high across the northern beaches and moderate across VA Beach and Eastern Currituck today. The rip current risk drops to moderate north/low south on Tuesday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 AM this morning to 1 AM EDT Tuesday for ANZ630>632-634. Small Craft Advisory from 10 AM this morning to 10 PM EDT this evening for ANZ635>637-639. Small Craft Advisory from 10 AM this morning to 4 AM EDT Tuesday for ANZ650-652. Small Craft Advisory from 1 PM this afternoon to 1 AM EDT Tuesday for ANZ654-656.