textproduct: Wakefield

WHAT HAS CHANGED

Slight Risk for today has been pushed south and now only encompasses NE NC (Marginal Risk elsewhere).

KEY MESSAGES

1) Shower and thunderstorm chances trend higher today along with high humidity. Slight Risk today for NE NC/Marginal risk elsewhere.

2) Marginal Risk for Severe storms along and S of I-64 Sunday. Dry with seasonable temperatures Monday-Tuesday.

3) A significant heat wave leading to Headlines is likely later in the week into the Holiday weekend, especially Thu-Fri. Shower/thunderstorm chances remain very low through Thursday.

DISCUSSION

As of 330 AM EDT Saturday...

KEY MESSAGE 1...Shower and thunderstorm chances trend higher today along with high humidity. Slight Risk today for NE NC/Marginal risk elsewhere.

A westerly upper level flow prevails early this morning with a sfc frontal boundary nearly stationary from the OH Valley ENE into western PA. With the upper flow staying nearly W-E today, expect the front to generally stay north of the FA, potentially close enough for some scattered AM showers (iso tstms) brushing our northern zones, while conditions remain mainly dry elsewhere. The latest 00Z RRFS as well as the 06Z HRRR have backed off a bit on convective coverage later today, with the stabilizing convective outflows/debris cloudiness across the area this morning, along with some lingering cloud cover and a reinforced stable outflow pool across at least the northern half of the FA. SPC has downgraded the Slight Risk that had been over southern VA to a Marginal for today, with the Slight now confined to NE NC.

Farther south, minimal impacts over the southern half of the area will allow for more in the way of sunshine, and subsequent late day destabilization ahead of an approaching (stronger) afternoon shortwave, which will trigger convection. A very warm to hot and moderately humid airmass will drive DCAPE values into the 1000-1500 J/kg range S of the VA-NC border, making this area a bit more conducive to severe weather. For that reason, a Slight Risk (Level 2 of 5) remains for NC. Given decent W-WNW flow aloft and 20-30 kt of 0-6km bulk shear, organized clusters or line segments, capable of producing localized damaging wind gusts will be the primary threat. Storm motions should generally be progressive enough (15-20 kt) to limit the widespread flash flood threat, though brief hydro issues cannot be ruled out if convection coalesces over urban areas.

KEY MESSAGE 2...Marginal Risk for Severe storms along and S of I-64 Sunday. Dry with seasonable temperatures Monday-Tuesday.

Convective coverage is expected to be a bit less on Sunday for northern areas, but still expect high chc to low-end likely PoPs across southern and western portions of the FA as the front begins sinking south through the area and the low- level flow becomes N-NE across northern portions of the FA. Though once again, potential for damaging wind gusts persists across Hampton Roads into NE NC, albeit a bit earlier in the day through around sunset. Dry and slightly less humid Monday and Tuesday, with temps in the mid- upper 80s Monday and upper 80s to lower 90s Tuesday as high pressure builds toward the area from the NNE.

KEY MESSAGE 3...A significant heat wave leading to Headlines is likely later in the week into the Holiday weekend, especially Thu-Fri. Shower/thunderstorm chances remain very low through Thursday.

A strong upper ridge slowly drifts east from the OH Valley to the central Appalachians later in the week. There are some subtle differences in the precise location, but confidence is high that this setup will lead to a significant heat wave for the local area. The MEX numbers with highs peaking only in the mid to upper 90s locally look to be too cool given a strong consensus for H5 heights >595 dm and 850 mb temps of 21-23C, this is likely being too influenced by climo. With that said, have continued to cut a few degrees off of the NBM temperatures for highs Wednesday- Friday; current forecast is for highs Thursday- Friday ranging from the upper 90s to the low 100s area-wide (with the highest temperatures for the interior MD eastern shore and central and south central VA). The weak sfc pressure gradient will tend to allow some aftn seabreeze development, locally bringing steady or falling late day temperatures. The caveat will be the higher dew pts along the coast so peak heat indices may be similar. Also continued to make some adjustments downward with aftn dew P's from the NBM (especially from the I-95 corridor and P's west). The latest forecast shows heat indices of 105-110 F fairly widespread for Thursday and Friday (with pockets of 110+ possible).

The only real opportunity for showers and storms in this pattern would be with "ring of fire" type convective complexes, but given the latest location of the upper ridge this does not appear very likely so rain chances are quite low Wed-Thu, with some slight chc to low chc PoPs by late Friday. This will all be better resolved as we get closer. The bottom line is that preparations should be made now for a period of hot temperatures/heat indices late next week.

AVIATION /07Z SATURDAY THROUGH WEDNESDAY/

As of 200 AM EDT Friday...

VFR conditions prevail as of 06z. A weak boundary settles in from the N through sunrise, and this has the potential to produce some MVFR CIGs, especially after ~10Z, lasting through ~15z. There is a better chc of showers/tstms later this aftn. Confidence in timing is still rather low. However, periods of sub- VFR conditions are likely in any showers/tstms. The wind will generally be light out of the S to SW tonight through Saturday, and could shift to easterly along the coast later this aftn. Any stronger tstms this aftn into the early evening could produce some locally stronger wind gusts.

Outlook: MVFR/IFR cigs are possible once again late tonight through early Sunday morning. Shower/tstm chances return Sunday aftn (lowest chance for SBY, highest southern VA and NE NC terminals). Prevailing conditions will be VFR outside of convection. VFR conditions are expected to return by the beginning of next week and continue through the middle of next week as high pressure builds S across the area and then settles offshore.

MARINE

As of 330 AM EDT Saturday...

Key Messages:

- Benign marine conditions are expected to prevail through much of the week. Scattered thunderstorm activity is expected for the next two days ahead of a weakening cold front.

Early morning weather analysis shows high pressure off the coast and a weak stationary front across PA. The pressure gradient ahead of the weak front remains weak allowing winds to be light out of the WSW around 10kt. Seas remain low this morning with 1ft seas in the bay and 2-3ft across the ocean. Through the day winds will shift more out of the south as the decaying front approaches the area. Winds will be around 10 kt with gusts nearing 15kt. In addition, scattered showers and thunderstorms are expected today across the waters. Some of these storms maybe strong to severe potentially producing gusts over 34kt. Seas will likely remain the stagnant through day with around 1-2ft across the bay and 2-3ft across the ocean. The decaying front will pass through the area by Sunday but the pressure gradient will be weak and winds will likely to hover around 10kt out of the NE. Additional storms are forecasted for Sunday afternoon and some maybe strong to severe potentially producing wind gusts above 34kt. Through the rest of the forecast period Sub-SCA conditions are expected to prevail. However, will not that Monday winds shift out of the NE and decided to up the waves to 4ft near shore as some guidance continues to hint on a slightly tighter pressure gradient.

Rip Currents: Low rips are forecasted for today and Sunday. However, Sunday there is a possibility of the Northern beaches being upgraded to moderate due to onshore flow, but that is all depending on the timing of the front and when winds will shift. There was not enough confidence at this time for an upgrade. Continues with Moderate Rips for all beaches Monday due to onshore flow and 9-10 sec periods.

AKQ WATCHES/WARNINGS/ADVISORIES

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