textproduct: Raleigh

WHAT HAS CHANGED

As of 1255 AM Saturday...

* Pre-frontal showers and isolated thunderstorms are expected Sunday morning in the Piedmont. The associated cloudiness and showers will limit instability in the warm sector there Sunday. There still appears to be adequate instability for the development of scattered thunderstorms in the Coastal Plain and Sandhills, and possibly the eastern Piedmont Sunday afternoon. Marginal risk continues.

* Frost/Freeze possible Tuesday night.

* Potential elevated fire danger risk again this week.

KEY MESSAGES

As of 631 AM Saturday...

1) Showers and possibly a few thunderstorms are expected Sunday ahead of a cold front. There continues to be a marginal risk of a severe wind gust, especially if enough instability can develop in the eastern Piedmont eastward to the coast Sunday afternoon.

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

3) A period of elevated fire danger is possible Tuesday through Thursday next week

DISCUSSION

As of 1255 AM Saturday...

KEY MESSAGE 1... Showers and possibly a few thunderstorms are expected Sunday ahead of a cold front. There continues to be a marginal risk of a severe wind gust, especially if enough instability can develop in the eastern Piedmont eastward to the coast Sunday afternoon. QPF of 0.25 to locally 0.60.

It appears that a pre-frontal trough or convective outflow will arrive as a boundary that produces showers and isolated thunderstorms well ahead of the cold front Sunday morning. There is adequate moisture return for a narrow window of 3-5 hours of much needed rainfall with this event. To the east of the Triad region, a Marginal Risk of severe still exists for the potential for isolated strong to locally damaging wind gusts with any thunderstorms Sunday from late morning through the afternoon. The warm sector should be characterized with dew points of 60-65 with temperatures in the upper 70s to lower 80s (potentially). Thus Sbcape of up to 500 to 1000 j/kg expected mainly east of Raleigh. The big question will be if the pre-frontal convection moves quickly through late morning into the early afternoon stabilizing the region, and how far east this stabilizing shower activity gets. New storms should develop along the pre-frontal trough / convective outflow somewhere over the NE-E Piedmont late morning and move eastward during the afternoon. QPF of 0.25 to 0.60 appears to be the most likely outcome, with the greater than 0.50 localized.

The front will move through later in the day with another narrow convective line (likely not severe due to previous overturning) with additional light QPF.

The front will clear the region Sunday night and this will set the stage for colder week, with dry weather all week.

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

An anomalously strong 1038 mb continental polar high over Wisconsin and the Upper MS valley Tuesday will settle into the Mid-Atlantic states midweek Wednesday, resulting in a favorable period of frost or freeze conditions. The high is forecast to migrate off the New England coast by Thursday, but its influence is expected to persist into the early part of next weekend with east-southeasterly flow. That should keep most of central NC dry through much of next week. The coldest lows are forecast to still be Wednesday and Thursday mornings, where low to mid 30s are favored, especially in the typically cooler spots. The airmass is typical for what we usually see in mid-February. The lowest values from the EPS statistical guidance indicate some upper 20s to low 30s are possible, particularly for areas along and north of US-64, where NBM probabilities for 36F or lower are highest. Highs should generally be below normal in the 60s around the middle of next week, with the coolest values expected Wednesday. Gradual moderation of the airmass should push highs back into the 70s by next Friday.

KEY MESSAGE 3... A period of elevated fire danger is possible Tuesday through Thursday next week

As the anomalously strong polar high builds down from the Great Lakes Tuesday and settles to our northeast on Wednesday, there will be the potential for elevated fire danger. With a tightened pressure gradient as the high builds down into the region, gusts of 20-25 mph are possible in the afternoons Tue and Wed. The flow will be likely be NNW Tue and NNE Wed. Correspondingly, with precipitable water values near the 10th percentile, the airmass will be quite dry, with ensemble guidance suggesting upper 20s to low 30s dewpoints. With highs in the 60s, that would easily support minimum RH values during the day in the upper 20s to lower 30s percent. Depending on how much rain we get Sunday with the front and how fast we can dry out, these conditions would support a possible increased fire danger. These conditions could persist into late-week with slow moisture recovery.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

As of 630 AM Saturday...

An area of locally higher low-level moisture around and southwest of FAY may also result in sub-VFR conditions through 14z-15z, and with some ground fog as well. Otherwise, some IFR cigs early in the Triad will dissipate by late morning. Generally VFR conditions are expected this afternoon. The SSW winds will increase to 10-15 kt today and become gusty in the west this afternoon to 22 kt. Winds will become gusty tonight in all areas as the prefrontal trough approaches (expect some gusts to 20-25 kt).

Outlook: A pre-frontal trough will focus showers and possibly a few thunderstorms and flight restrictions as they move across cntl NC Sunday into Sunday evening (east). A return to VFR expected Sunday night into next week.

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.