textproduct: Raleigh

WHAT HAS CHANGED

As of 225 AM Friday...

* A slight slowing trend with the Sunday cold front. Otherwise, there's increased confidence in high rain chances mid-late morning Sun in the NW Piedmont and Sun afternoon into early evening elsewhere.

KEY MESSAGES

As of 225 AM Friday...

1) Continued quite warm today and Saturday. Widespread showers and some storms still expected Sunday ahead of a cold front. A severe risk cannot be ruled out.

2) Turning cooler and below normal early to middle of next week, with frost/freeze conditions possible midweek.

DISCUSSION

As of 225 AM Friday...

KEY MESSAGE 1... Continued quite warm today and Saturday. Widespread showers and some storms still expected Sunday ahead of a cold front. A severe risk cannot be ruled out.

Models remain consistent with highs mainly in the lower 80s today and in the lower-mid 80s Sat, roughly 10 to 15 degrees above the normal highs for this time of year. We continue to track a strong cold front forecast to move through Sun and Sun night. By Sun morning, most ensemble and deterministic guidance indicates that the front will stretch along the spine of the Appalachians from western PA into far eastern TN and into the Lower MS valley. A continued slower trend of the frontal passage appears to remain with the 12z suite of ensemble guidance, with the main cold front moving through late Sunday night. Ahead of the front, however, a pre-frontal effective front may race ahead of the main boundary and induce morning to early afternoon convection, suggested by the operational GFS/CMC solutions. Regardless, deep moisture will aid widespread showers by the afternoon to early evening as PW's approach maximum daily values for early April in the 1.3-1.4 inch range. Most ensembles suggest a range of one quarter to one half inch of rainfall across the area, not enough to make a dent in the expanding drought. Sufficient instability will ultimately depend on timing of the front and if any pre-frontal convection will develop, which would weaken any daytime instability. The severe risk, therefore, appears conditional, and bears watching with 35 to 40 kt of deep- layer shear. A suite of AI convective guidance varies on potential severe strength, but there is enough agreement signaling a 15 to 30 percent risk somewhere over central to eastern NC, with the NCAR AI most aggressive and the NSSL AI focused mainly from the Coastal Plain to the coast.

KEY MESSAGE 2... Turning cooler and below normal early to middle of next week, with frost/freeze conditions possible midweek.

In the wake of the cold frontal passage late Sunday night, a cooler airmass is forecast to build into the region. Most guidance shows that on Monday cool high pressure settles in, with highs hovering slightly below normal in the mid to upper 60s. The true cooler airmass arrives late Tuesday through early Thursday, when ensemble and deterministic guidance shows good agreement on a Continental polar high of near 1038 mb that settles down into the Mid-Atlantic states. The coolest period looks to be Wednesday when the high will nose down from PA and central NC is in a NE flow regime. Highs midweek may range from the upper 50s to low 60s, some 10 degrees below average. Of greater importance is the potential for frost/freeze conditions Wed and Thu mornings in the below normal airmass. Statistical and ensemble guidance indicate potential low to mid 30s Wed morning, when optimal radiational cooling is favored. The NBM currently indicates a 20-percent chance of 32F or lower and a 40 to 50-percent chance of 36F or lower in the typical cooler spots of central NC. Temperatures are forecast to moderate Thu onward as return flow sets back in over the southeast US.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

As of 600 AM Friday...

Areas of IFR-MVFR ceilings are expected over the Piedmont, to near or just west of FAY and RWI, through around 14z-15z before dissipating. A return to VFR conditions are expected by mid to late morning lasting into tonight. There may be additional IFR stratus by 10z tonight in the Triad.

Outlook: Low-level moisture will gradually deepen and support the development of IFR-MVFR ceilings again Sunday morning, ahead of a cold front and chance of convection and flight restrictions that will move across cntl NC Sun afternoon.

CLIMATE

Record High Temperatures:

April 4: KGSO: 87/2025 KRDU: 90/2025

Record High Minimum Temperatures:

April 5: KFAY: 67/2025

RAH WATCHES/WARNINGS/ADVISORIES

None.