textproduct: Raleigh

WHAT HAS CHANGED

* No significant changes.

KEY MESSAGES

As of 215 PM Thursday...

1) Less thunderstorm coverage this afternoon and Friday afternoon compared to Wednesday afternoon, while heat concerns persist across the southern Coastal Plain this afternoon.

2) Continued warm Sat, with increased chances for diurnally driven convection through the weekend. Best chances shift south through mid- week, with near to below normal temperatures Sun through Tue.

DISCUSSION

As of 215 PM Thursday...

KEY MESSAGE 1... Less thunderstorm coverage this afternoon and Friday afternoon compared to Wednesday afternoon, while heat concerns persist across the southern Coastal Plain this afternoon.

While one or two very light radar echoes have developed along the US- 1 corridor this afternoon, overall thunderstorm coverage is expected to be less than yesterday. The bulk of convective-allowing models show the most widespread coverage of showers and thunderstorms well to the north across the DC metro area down to Richmond, as well as across the western half of North Carolina. Although diurnal cumulus has developed across the entire forecast area, the deepest clouds are along and to the west of US-1. Despite these early radar echoes along US-1, still believe that the greatest coverage for precipitation will remain contained to the Triad during the mid to late afternoon, with all convection coming to an end around sunset. Friday's pattern looks similar to today, although by the end of the afternoon, a slight chance of showers and thunderstorms should expand across the entire forecast area.

Air temperatures are a couple degrees cooler than this time yesterday, although dewpoints remain in the upper 60s and lower 70s. However, neither the air temperature nor the dewpoints have come down much across the southern Coastal Plain, where heat index values around 105 degrees still remain possible through the afternoon. A Heat Advisory is in effect for Sampson and Hoke Counties until 8pm.

KEY MESSAGE 2... Continued warm Sat, with increased chances for diurnally driven convection through the weekend. Best chances shift south through mid-week, with near to below normal temperatures Sun through Tue.

Aloft, a s/w will help amplify the longwave trough as the former progresses esewd across the OH Valley and mid-Atlantic over the weekend. Meanwhile, a mid-upper level anticyclone will strengthen and lift nwd across the Rockies, then shift ewd over the nrn/cntl Plains. The trough will push south and east of the region next week as the high builds across the nrn/n-cntl CONUS. At the surface, a trough will remain in place until a backdoor cold front pushes swd- sswwd across the area Sun/Sun night. High pressure will ridge swd across and remain over the area through early-mid week, while an area of low pressure develops off/along the Carolina coast, though details remain uncertain. Expect the greatest chances and coverage of convective activity as the trough moves across the region Sat and Sun. Specific details wrt instability and available moisture vary between the NAM and GFS forecast soundings, with the GFS more moist and NAM more unstable, but overall the airmass is not expected to change significantly until after the fropa Sun. As for temperatures, the warmest day should be Sat, with highs ranging from upper 80s north to mid 90s south. Mon should be the (relatively) coolest day, with highs ranging from low 80s NW to mid 80s SE.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

As of 749 PM Thursday...

TAF period: Generally VFR conditions are forecast for the next 24 hours. However, isolated thunderstorms are possible Friday afternoon and evening.

Outlook: Scattered thunderstorms are expected Saturday and Sunday, mainly in the PM hours.

There will be a lower chance of a shower or storm Monday, mainly confined to southern and western areas from INT/GSO/FAY, with all locations expected to be VFR Tuesday.

CLIMATE

Record High Temperatures:

July 10: KRDU 99/1993 KFAY 103/1986

Record High Minimum Temperatures: July 10: KGSO 77/1981 KRDU: 77/2024 KFAY: 77/1998 July 11: KGSO 75/1992 KRDU: 77/1981 KFAY: 77/2024

RAH WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 8 PM EDT this evening for NCZ088-089.