textproduct: Raleigh

WHAT HAS CHANGED

As of 330 PM Saturday...

* Nothing significant

KEY MESSAGES

As of 330 PM Saturday...

1) Scattered showers and possibly a few thunderstorms are expected Sunday along a pre-frontal trough and cold front. A Marginal risk (Level 1 of 5) for severe storms with damaging wind gusts remains, especially where pockets of stronger heating and destabilization may occur from the eastern Piedmont ewd to the coast Sunday afternoon- early evening.

2) Cooler temperatures next week may result in the potential for frost/freeze headlines Tuesday/Wednesday nights.

3) The potential for heightened fire weather concerns returns next week.

DISCUSSION

As of 330 PM Saturday...

KEY MESSAGE 1... Scattered showers and possibly a few thunderstorms are expected Sunday along a pre-frontal trough and cold front. A Marginal risk (Level 1 of 5) for severe storms with damaging wind gusts remains, especially where pockets of stronger heating and destabilization may occur from the eastern Piedmont ewd to the coast Sunday afternoon-early evening. QPF of 0.25" to locally around 0.75".

A mid/upr-level cyclone will lift across the upr Great Lakes tonight, while a trailing shortwave perturbation now over srn AB/SK will dig across the nrn Plains and mid MS Valley. The trailing feature will then lift quickly newd across the upr OH Valley and nrn Middle Atlantic through 00Z Mon. Net, 40-60 meter 500 mb height falls will result across cntl NC from late tonight through much of Sunday night, while related, swly flow through the mid-levels will gradually strengthen through the 35-50 kt range, but with the stronger ranges of that flow that will likely exist just behind the warm/moist sector over e-cntl and ern NC. Preceding those features, a convectively-amplified mid-level trough and band of vorticity maxima, related to a large area of deep convection and trailing stratiform rain now stretching from the mid-South to south-cntl TX, will progress into the srn Appalachians and wrn Carolinas by 12Z Sun and then reach the srn Middle Atlantic coast by around 00Z Mon. That trough and related mid-level moist/cloud band, and probable remnants of upstream convection, will likely modulate instability and forcing influences over the warm/moist sector over cntl NC.

At the surface, a synoptic cold front will extend through, or just west of, the Blue Ridge at 12Z Sun, then progress ewd and into the nw Piedmont during the afternoon and the remainder of cntl NC through early to mid-evening. Preceding the front and with lesser predictability, the remnants of an upstream QLCS and associated composite outflow will probably be in the process of moving into the srn/wrn Piedmont around 12Z Sunday. While it remains unclear to what degree this feature and convection will be maintained as it progresses ewd throughout day, the most likely scenario will be for continued weakening of this convective/precipitation band as it progresses into a diurnal minimum of instability during the morning hours, with probable redevelopment in a differential heating zone and subtle surface trough/confluence axis as it progresses into a diurnally-destabilizing environment over e-cntl and ern NC through the afternoon-evening. This activity will likely occur in an environment characterized by weaker mid-level flow noted above, and effective shear magnitudes of perhaps 30-35 kts, amid generally unidirectional flow. Strong to locally damaging wind gusts may nonetheless result from the most intense cells, particular where pockets of stronger surface heating and steeper low-level lapse rates may occur. Behind this activity and along/immediately ahead of the advancing synoptic front, forcing for ascent will be focused and mid-level flow stronger. However, instability will likely be lower there from cooler/less warm surface temperatures in the wake of the earlier day convection and clouds; and as such, a shallow band of frontal, probably sub-severe convection will result and progress ewd across cntl NC through the evening.

While rainfall amounts will likely average a quarter to half inch over cntl NC, localized maxima of around three quarters of an inch or more will result along the track of stronger and more sustained cells, most likely from the ern Piedmont/Sandhills through the Coastal Plain. And some areas that get grazed or missed from those cells may rely more on remnant stratiform rain that may only total several hundredths to a tenth of an inch.

KEY MESSAGE 2... Cooler temperatures next week may result in the potential for frost/freeze headlines Tuesday/Wednesday nights.

While one cold front will bring the potential for severe weather on Sunday along with cooler weather for Monday, a second cold front crossing the region Monday night will bring a reinforcing shot of cold air to North Carolina. Sunday and Monday night's lows will be near normal for early April, in the 40s. However, widespread lows in the 30s are forecast for Tuesday night, with slightly warmer temperatures expected Wednesday night. The current forecast still calls for the wind to be between 5-10 mph Tuesday night, but the wind could be lighter Wednesday night, which would allow for ideal radiational cooling conditions and resulting in the temperature forecast decreasing Wednesday night. Frost/freeze headlines began across central North Carolina on April 1, and may be needed each of these two nights.

KEY MESSAGE 3 ... The potential for heightened fire weather concerns returns next week.

With high pressure settling in behind the second cold front, relative humidity values will be low across much of the area. All of central North Carolina will have minimum RH values in the 20s on Tuesday, with 20s/30s on Wednesday and 30s/40s Thursday through Saturday. Although wind gusts shouldn't be above 15-20 mph through the extended forecast, nearly 90% of the state is under a severe drought, and low relative humidity values will heighten any potential fire danger conditions. Sunday will be the only potential day for rain out of the next seven days, and it will do little to improve the worsening drought situation.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

As of 150 PM Saturday...

This morning's area of MVFR cumulus clouds have lifted to VFR. VFR conditions should continue to prevail through the day today. Southwesterly winds are expected to continue gusting to around 22kts until around sunset, with a low end chance of a few showers in the Triad this afternoon. Overnight, winds look to remain elevated at the surface at around 8-12kts, with some gusts in excess of 18kts remaining possible in the overnight period, reducing the risk of LLWS. Additionally, MVFR to IFR ceilings will start to move into the region late tonight, bringing flight restrictions to the Triad and potentially RDU by sunrise. With these lower ceilings, continued gusty winds and rain are expected as a cold front approaches and starts to move through the region. Ceiling restrictions look to hold off until around 18Z at FAY and RWI tomorrow.

Outlook: Flight restrictions from the cold front are expected to continue through Sunday evening. VFR conditions should then prevail Sunday night into next week.

CLIMATE

Record High Minimum Temperatures:

April 5: KFAY: 67/2025

RAH WATCHES/WARNINGS/ADVISORIES

None.