textproduct: Raleigh

WHAT HAS CHANGED

* Minimal changes to the forecast.

KEY MESSAGES

As of 205 AM Tuesday...

1) All of central North Carolina will be under a slight (level 2 of 5) risk for severe thunderstorms today, primarily in the late afternoon and evening hours.

DISCUSSION

As of 205 AM Tuesday...

KEY MESSAGE 1... All of central North Carolina will be under a slight (level 2 of 5) risk for severe thunderstorms today, primarily in the late afternoon and evening hours.

A cluster of showers and thunderstorms is currently near the Michigan/Ohio border and is forecast to drop to the south-southeast overnight, reaching West Virginia by morning and continuing to the southeast. The cluster is likely to be dissipating as it reaches North Carolina, bringing some scattered showers to the western half of the state, but the thunderstorm potential is minimal with this wave.

However, as a cold front moves to the south behind the initial cluster of showers, this will provide more widespread forcing for precipitation and is likely to bring showers to much of central North Carolina, with the highest chances for rain to the east of US- 1. It is with this second round of precipitation that severe weather will be potentially locally. The reason for noting the initial cluster of showers is that the remnant cloud cover is likely to reduce the amount of instability farther to the west, reducing, but not eliminating, the chance for severe weather in the Triad. Most of the area will have MUCAPE values at least 2000 J/kg, and the effective shear will be 30 to 40 kts, with the greatest shear to the northwest. The most likely timing for severe weather will be from 4- 8pm, moving from northwest to southeast. The 06Z forecast from the Storm Prediction Center is very similar to their forecast from Monday afternoon: the primary threat will come from damaging wind gusts, there will be a secondary threat for isolated tornadoes, greatest from the Triangle north and east, and isolated large hail cannot be ruled out to the west of US-1. All rain should come to an end shortly after midnight.

AVIATION /11Z TUESDAY THROUGH SATURDAY/

As of 650 AM Tuesday...

TAF period: While FAY has less than an hour of visibility restrictions, MVFR visibilities remain in the vicinity of the terminal. RWI has had visibilities bounce between LIFR and MVFR, and will keep them MVFR to start the TAF period. An area of showers/storms currently moving south-southeast over West Virginia will eventually pass over Virginia and across the western half of North Carolina, providing additional cloud cover if not some showers with its decay as it approaches. While this will bring a chance of showers, primarily to INT/GSO, the main threat for precipitation will come later in the afternoon ahead of the synoptic cold front crossing the region. Have maintained TEMPO groups (PROB30 at FAY) for TSRA, with some slight adjustments for timing when thunderstorms are most likely at each terminal as well as adding prevailing groups for showers at FAY/RWI. Showers/storms will end from northwest to southeast through the evening, likely ending by 06Z at FAY. There is the possibility for MVFR clouds to form near RWI after 06Z, but ceilings appear unlikely.

Outlook: The next chance of showers/storms should not be until Saturday, and most probably at INT/GSO.

RAH WATCHES/WARNINGS/ADVISORIES

None.