textproduct: Raleigh

WHAT HAS CHANGED

* No significant changes were made.

KEY MESSAGES

As of 222 PM Friday...

1) Dangerous heat will persist and intensify across central North Carolina through the holiday weekend.

2) Mostly dry weather will persist through the weekend, then better rain chances return to start the work week.

DISCUSSION

As of 222 PM Friday...

KEY MESSAGE 1... Dangerous heat will persist and intensify across central North Carolina through the holiday weekend.

Under a building 596dm upper ridge that has shifted east over the heart of NC, heat has ramped up significantly today with 2pm temps already in the mid and upper 90s. Dewpoints are hovering in the upper 60s and lower 70s, resulting in heat indices in the 100-106F range at most observing sites, although some NC ECONet sites and other non-official weather stations report values up to 110F, especially across the Northern Piedmont and northern Coastal Plain. The Heat Advisory and Extreme Heat Warning remain unchanged for the rest of the day and tomorrow for the moment. We contemplated expanding the Extreme Heat Warning south of HWY 64, which is the current rough delineation between advisory and warning, but we will wait to see how high the heat indices end up this afternoon. Tomorrow is expected to be hotter across the board, but models indicate some drier 925mb air (evident on this mornings RNK roab) that settles over the Piedmont and keeps heat indices at least similar today.

Heat indices may not be as high on Sunday or even into Monday, as the upper ridge begins a slow weakening and low-level thicknesses nudge lower, but the cumulative impacts of multi-day highs around 100F and humid conditions will likely warrant additional Heat Advisories.

Other heat-related points:

- Overnight lows will generally remain in the mid to upper 70s, providing limited nocturnal recovery, allowing cumulative heat stress to increase as the event progresses.

- The greatest concern continues to be the prolonged duration of the heat rather than any single exceptionally hot day. Consecutive days of excessive heat and warm nights compound impacts.

- The experimental NWS Heat Risk product indicates Major to Extreme Heat Risk today through Monday. (wpc.ncep.noaa.gov/heatrisk)

- While isolated afternoon convection (particularly from Sunday on) may provide localized and temporary relief, coverage appears insufficient to significantly mitigate the overall heat hazard.

- Additional Heat Advisories will likely be needed on Sunday and Monday.

- Finally, the highest risk will be for those without effective cooling, individuals working or recreating outdoors, and other heat- sensitive populations as the prolonged stretch of above-normal temperatures continues into next week.

KEY MESSAGE 2... Mostly dry weather will persist through the weekend, then better rain chances return to start the work week.

As the deep high pressure holds over the mid-Atlantic, rain chances should remain relatively low through the weekend. An isolated shower or storm may be possible Saturday afternoon and evening in the northwestern portions of the CWA as a weak upper level disturbance is forecast to move over the region. However, if a shower or thunderstorm is able to form, it should be very isolated and brief in nature as the best forcing will be located to our north. Sunday also will have a small chance of an isolated shower or storm as the upper level ridge starts to breakdown, but most of the area should remain dry, with the best chance in the north again.

As the high weakens further and shifts southward at the beginning of the work week, rain chances will increase Monday and Tuesday afternoons and evenings. Widespread severe weather is not expected, however high PW values may allow for some stronger storms to create isolated strong to damaging winds and heavy downpours in water- loaded downdrafts. Ensemble guidance is still suggesting around 0.25 inch of rain both afternoons, however any stronger storms could locally enhance rainfall totals. A backdoor cold front looks to move through the region Tuesday night or Wednesday. This should bring the region back to a more typical summer-like pattern.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

As of 100 PM Friday...

TAF period: VFR conditions are expected through the 24 hour period. Isolated storms are possible near the NC/VA border Saturday afternoon but should remain north of TAF sites.

Outlook: Dry VFR conditions remain in the forecast through Sunday. a cold front will approach from the northwest early next week and bring unsettled weather.

CLIMATE

All-time High Temperature Record and Most Recent Date of Occurrence:

KGSO: 104/1914-07-27 KRDU: 106/2024-07-05 KFAY: 110/1983-08-21

Record High Temperatures:

July 3: KGSO: 98/1911 KRDU: 101/2012 KFAY: 102/2019 July 4: KGSO: 98/1970 KRDU: 101/twice KFAY: 98/2019 July 5: KGSO: 98/2012 KRDU: 106/2024 KFAY: 101/twice July 6: KGSO: 100/1977 KRDU: 102/1999 KFAY: 100/2024

All-time High Minimum Temperature Record and Most Recent Date of Occurrence:

KGSO: 80/2007-08-09 KRDU: 80/2025-07-18 KFAY: 84/1928-06-22

Record High Minimum Temperatures:

July 3: KGSO: 76/2018 KRDU: 79/2023 KFAY: 76/2023 July 4: KGSO: 73/2018 KRDU: 79/1902 KFAY: 78/1913 July 5: KGSO: 74/1999 KRDU: 78/2024 KFAY: 77/2005 July 6: KGSO: 76/1999 KRDU: 79/1900 KFAY: 77/2024

RAH WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning from noon today to 8 PM EDT Saturday for NCZ007>011-021>028-038>041-043. Heat Advisory from noon today to 8 PM EDT Saturday for NCZ042- 073>078-083>086-088-089.