textproduct: Wakefield

WHAT HAS CHANGED

Extreme Heat Warnings have been issued/continued for all VA and MD Eastern Shore counties (excluding the Maryland Beaches) tomorrow through Saturday as heat indices of 110F or greater are expected.

Heat Advisories have been issued for all NE NC counties for Friday, as well as for the MD Beaches.

An Extreme Heat Watch has been issued for the NE NC counties (excluding eastern Currituck) for Saturday.

KEY MESSAGES

1) A prolonged and widespread heat wave will continue this afternoon through Sunday, before breaking down by late this weekend. This has the potential to be the most significant in both magnitude and duration since July 2012 for most of the forecast area. Additionally, strong to severe storms are possible Fri-Sun.

2) Temperatures gradually trend closer to normal by early next week, with the potentially for unsettled weather.

DISCUSSION

As of 325 PM EDT Thursday...

KEY MESSAGE 1...A prolonged and widespread heat wave will continue this afternoon through Sunday, before breaking down by late this weekend. This has the potential to be the most significant in both magnitude and duration since July 2012 for most of the forecast area. Additionally, strong to severe storms are possible Fri-Sun.

An anomalously strong upper level ridge continues to remain dominant across the eastern half of the United States today before starting to break down by late this weekend. Confidence remains high that this ridge will continue to lead to a significant heat wave for the local area, potentially the most widespread and of longest duration since July 2012. Current temperatures across the area this afternoon range between 90-99F, with the highest temperatures being observed in the NW piedmont. Similar to yesterday, dew points have not mixed out quite as much as expected and have actually increased, so heat indices have been able to easily climb to 100F, with some areas between Richmond and Louisa seeing a heat index of 110F+. GOES Visible satellite is highlighting some patches of cloud cover across portions of the area, though this cloud cover is having little impact on temperatures at this time.

As of now, Friday looks to be the hottest day as the ridge is firmly in place and high pressure remains dominant over the area, so the hot and humid airmass will be locked in place. There is good confidence that a majority of the area could see heat indices of 105F+. Due to this increased confidence in this anomalously high heat expected, have decided to expand the Extreme Heat Warning in place today to the remain of our VA counties for tomorrow and Saturday. Heat Advisories have been issued for the NE NC counties, including eastern Currituck and the Maryland Beaches. Most guidance continues to show dew points mixing out by tomorrow afternoon which has been reflected in the forecast, however, with both yesterday and today seeing increasing afternoon dew points (not typical), we will continue to adjust the forecast as necessary to more accurately represent tomorrow's heat index/WBGT. Regardless of the exact specifics, tomorrow will be dangerously hot so precautions need to be taken if venturing outdoors. While SPC has a Marginal Risk for severe storms across the northern portions of the area, this will be very conditional on if storms can actually develop. Since there is so much uncertainty in storms tomorrow, have not factored them into the temperature forecast.

While there is a little more uncertainty in Saturday's temperatures, due to the possibility of convection in the afternoon/evening hours and the ridge starting to try and break down, have decided to increase temperatures a degree or two to align with all guidance, with widespread 95-100F+ degrees currently forecast. This is the reasoning behind the extension of the Extreme Heat Warning through Saturday. Temperatures have trended higher in NE NC, so decided to issue and Extreme Heat Watch for all of those counties (excluding eastern Currituck) for Saturday. Low temperatures tonight through Saturday night will likely only drop into the low to middle 70s, with urban areas only dropping to between 75-80F. This will allow for little relief during the overnight hours from the heat. SPC has upgraded most of the aside from NE NC and far southern VA to a Slight Risk for severe weather for Saturday, with a Marginal Risk extending across the remainder of the area. The main threat with any storms will be damaging winds due to the large amount of DCAPE/instability that will be present because of the very hot temperatures expected during the day.

As the ridge continues to break down by Sunday, the heat looks to linger for one last day, with temperatures forecast to reach upper 90s to localized areas potentially seeing one last round of triple digits. There does remain some uncertainty with cloud cover and chance for storms on Sunday, so have not extended any headlines to include this day. SPC has continued to highlight our area in a Slight Risk in their extended outlook for Sunday, with the main threat once again being damaging wind gusts. While the area is still in a drought, the slow motion of storms and high PW expected on Saturday or Sunday could lead to localized flash flooding, especially in urban areas and areas with poor drainage.

2) Temperatures gradually trend closer to normal by early next week, with the potentially for unsettled weather.

By early next week, the upper level flow turns more NW as the ridge breaks down. As this occurs, this could potentially bring additional rounds of showers and thunderstorms and possibly a brief period of severe weather across the area. In addition, temperatures will likely fall back to seasonable early next week as the ridge breaks down, with highs finally trending into the upper 80s to lower 90s by Tuesday.

AVIATION /19Z THURSDAY THROUGH TUESDAY/

As of 155 PM EDT Thursday... VFR conditions will continue through the TAF period, with mostly clear skies and S-SW winds prevailing. Winds will range between 5-10 kts, then will become variable overnight and into tomorrow morning.

Outlook: VFR conditions will continue through most of this week and into the weekend as high pressure settles offshore. There is potential for isolated to scattered showers/storms each afternoon and evening Saturday through early next week, which could lead to briefly degraded flight conditions at any terminal that sees any of this convection.

MARINE

As of 300 PM EDT Thursday...

Key Messages:

-Sub-SCA marine conditions are expected to prevail through the weekend, with mainly southerly winds.

This afternoon, high pressure extends from off the Mid Atlantic coast into the Southeast US. With high pressure in place, S-SW winds remain generally light, averaging 5 to 10 knots. Winds increase slightly this evening into tonight, especially over the coastal waters, but will remain sub-SCA. Seas are running around 2 to 3 feet in the coastal waters and waves in the Chesapeake Bay are running around 1 to 2 feet. High pressure remains over the local area over the next few days allowing for continued, mainly light, southerly winds. Some diurnal wind speed and direction variability is likely to prevail for the next several days (mainly S-SW in the morning, becoming S-SE in the late aftn/evening). Isolated to widely scattered storms this weekend into early next week would be the only thing that would lead to brief higher winds. Waves in the Bay will remain between 1 to 2 feet, and seas across the nearshore coastal drop off to 1 to 2 feet tomorrow into the weekend.

Rip Currents: Low rip current risk Friday through the weekends nearshore waves drop to ~2ft.

CLIMATE

Record Highs:

- Site: Thu 7/2 Fri 7/3 Sat 7/4 Sun 7/5

- RIC: 100/1953 100/1954 100/2002 102/2012 - ORF: 100/1901 99/1954 98/1997 98/2012 - SBY: 99/2014 98/1954 100/1919 102/2012 - ECG: 97/1953 98/1954 100/1997 100/2012

Record High Mins:

- Site: Thu 7/2 Fri 7/3 Sat 7/4 Sun 7/5

- RIC: 76/2014 77/2014 77/1900 79/2012 - ORF: 78/2018 78/2014 79/2012 80/1999 - SBY: 77/1968 76/2014 78/2012 81/2012 - ECG: 76/2014 78/2014 78/2012 77/2024

EQUIPMENT

KAKQ radar is down due to mechanical issues without an estimated time of return.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...Extreme Heat Warning until 8 PM EDT Saturday for MDZ021>024. Heat Advisory from 10 AM to 8 PM EDT Friday for MDZ025. NC...Heat Advisory from 10 AM to 8 PM EDT Friday for NCZ012>017- 030>032-102. Heat Advisory until 8 PM EDT this evening for NCZ012>017- 030>032. Extreme Heat Watch from Saturday morning through Saturday evening for NCZ012>017-030>032. VA...Extreme Heat Warning until 8 PM EDT Saturday for VAZ048- 060>062-064-067>069-075>078-080>086-088>090-509>523. Heat Advisory until 8 PM EDT this evening for VAZ065-066-079- 087-092-097>100-524-525-528>531. Extreme Heat Warning from 10 AM Friday to 8 PM EDT Saturday for VAZ065-066-079-087-092-097>100-524-525-528>531. MARINE...None.