textproduct: Raleigh

WHAT HAS CHANGED

As of 200 AM Saturday...

* No appreciable changes to the going forecast

KEY MESSAGES

As of 200 AM Saturday...

1) There remains a marginal risk of hail and strong gusty winds this evening over our southwest counties. There is a non-zero threat of storms Monday in our southeast but confidence remains low.

2) The combination of unseasonably hot temperatures, low humidity, and a passing cold front favors an elevated fire danger risk on Monday.

DISCUSSION

As of 200 AM Saturday...

KEY MESSAGE 1... There remains a marginal risk of hail and strong gusty winds this evening over our southwest counties. There is a non-zero threat of storms Monday in our southeast but confidence remains low.

A cold front presently draped over the OH valley and northern Mid- Atlantic will move into our region today and stall out somewhere near the NC/SC border. The actual boundary once it makes it into NC will more or less be a wind shift, with no real change in the airmass as highs reach about 15 degrees above normal in the upper 70s to lower 80s. However, the boundary will set up a convergence and theta-e axis stretching from western NC into Charlotte and into the southern Piedmont. A shortwave over the Mid MS and TN valley region will track into AL/GA this evening.

Central NC will likely be on the stable side of this theta-e boundary, with dewpoints only in the lower 50s in our southern Piedmont. However, the 850-mb WAA will help generate lift atop the boundary, feeding on PW's about 180-percent of normal of an inch. The latest 00z HREF members still vary quite a bit as to coverage and location, but the general consensus shows a cluster of showers/storms developing over eastern TN into the NC mountains and Charlotte area before tracking ESE into the NC/SC region. The HRRR/NSSL are the further north solutions, with activity perhaps reaching the southern Triad and Triangle areas, while other solutions keep the activity over the southern Piedmont and Sandhills. It would appear the best chance is over the southern Piedmont into the Sandhills, but all will depend on the location of the moist boundary. The main time frame looks to be from about 5-6 pm until 11p-12a. A Marginal Risk remains in place for the southern Piedmont and Charlotte region. While the surface is largely stable, parcels elevated to 850-mb can feed on 500-1000 J/kg of CAPE given fairly steep mid-level lapse rates of 7 C/km and 30-35 kt of effective shear. Some guidance suggests a meso-low or MCV may form to enhance this lift above the inversion. Given these conditions and elongated hodographs, hail is a primary risk if a few supercells can develop. But locally damaging winds are also possible given several point soundings indicating inverted-v profiles for evaporatively enhanced wind gusts. All in all, this is a conditional threat, given the lack of appreciable moisture but something we will be watching closely later today.

We continue to also watch a strong cold frontal passage during the day and evening on Monday. There still appears to be some differences in timing and orientation to the front. Some model solutions show the front sliding through from the NE, while other solutions such as the GEM and its regional RDPS show a passage more from the WNW. If the GEM were to verify, it could favor that non- zero threat of storms in our southeast counties Mon afternoon to early evening. However, moisture and instability remains a limiting factor, with much of the moisture transport focused along the coast during peak heating. As such, while a few AI models still suggest a severe risk, our confidence remains low at this time.

KEY MESSAGE 2... The combination of unseasonably hot temperatures, low humidity, and a passing cold front favors an elevated fire danger risk on Monday.

Whatever is left of the ill-defined boundary Saturday night will be long gone Sunday as southwest flow ramps up with low pressure over the northern Mid-Atlantic and high pressure over the eastern Gulf to western Atlantic. This pattern will be in place into Monday ahead of the cold frontal passage. The low-level temperature airmass will be typical for late June on Sun and partially in our southeast on Monday. Highs at all three of our climate sites will likely tie or break the record on Sun. Combined with southwest gusts of 15 to briefly 25 mph and RH dipping into the upper 20s to low 30s over the Piedmont could favor a low-end fire risk during the afternoon Sunday. The more heightened fire risk will be Monday afternoon to early evening over the western Piedmont. Although differences remain in the front orientation, a high fire danger remains in the SACC outlook for this time, along with a 40-percent or greater risk from SPC. If the flow is more WNW, the downslope flow combined with warm and dry temps and RH in the middle 20s would warrant this fire risk. It is too early to issue a Fire Weather Watch but will highlight in our HWO.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

As of 650 AM Saturday...

VFR conditions should prevail for the whole 24 hour TAF period. This morning, southwesterly winds up to around 10kts are expected to veer to northwesterly. Tonight, winds will become light and continue to veer to southeasterly. The best chance for any restrictions will come tonight as a few showers or thunderstorms may form in the southern Piedmont. Confidence remains low on exactly how far west showers may track, but included a PROB30 for -SHRA and associated gusts at FAY. Additional showers may also impact the Triad terminals and RDU tonight.

Outlook: VFR conditions should generally prevail. Showers and gusty winds up to 30 kts will be possible Monday afternoon and evening as a cold front moves through the region, with the best chance at FAY.

CLIMATE

Record High Temperatures:

March 22: KGSO: 85/1948 KRDU: 89/1907 KFAY: 88/1948

March 23: KFAY: 86/1948

Record High Minimum Temperatures:

March 22: KFAY: 63/1948

RAH WATCHES/WARNINGS/ADVISORIES

None.