textproduct: Raleigh

WHAT HAS CHANGED

As of 230 AM Sunday...

* High confidence in multiple days of record or near-record high temperatures through mid to late week.

KEY MESSAGES

As of 230 PM Sunday...

1) Fire weather concerns will persist through the week, with continued dry weather and low RH.

2) Dangerous heat wave likely this week, with several consecutive very hot days. Near record temperatures possible Tue through Sat.

DISCUSSION

As of 230 PM Sunday...

KEY MESSAGE 1... Fire weather concerns will persist through the week, with continued dry weather and low RH.

Dry conditions will persist across the region as minimum RH values drop into the 2530% throughout the coming week, particularly from Tuesday through Friday. While the pressure gradient remains relatively relaxedlimiting peak wind gusts to the 1520 mph range, the lack of significant moisture recovery is noteworthy. Although the forecast combination of humidity and wind is expected to remain just below official Increased Fire Danger or Red Flag Warning criteria, elevated fire concerns will persist until a wetting rain occurs. With no meaningful precipitation on the horizon, perhaps not until the tail end of the month, a statewide burn ban remains in effect for all of NC until further notice with all burning, including with previously-issued permits, prohibited.

KEY MESSAGE 2... Dangerous heat wave likely this week, with several consecutive very hot days. Near record temperatures possible Tue through Sat.

Confidence is increasing regarding the potential for a dangerous multi-day early-season heat wave across the Carolinas through the mid to late portion of the week. Mid level ridging will continue to steadily build from the Gulf across the Southeast states through the week, as Bermuda surface high pressure extends over the region, helping to deflect most fronts and precipitation systems to our W and N and keeping us generally dry under strong subsidence. Daily low level thicknesses are forecast to be well above normal (by 35-50 m) into at least Sat. Periods of clouds remain possible, including late Thu/Thu night when deterministic models bring a dampening shortwave trough (now off CA) into the region from the WSW. But otherwise, sunshine should be abundant, contributing to high heat stress and near record temps (see climate section below), with highs as much as 15 to 25 degrees above normal. The chance for several days of widespread 90s over central NC is increasing, especially for Wed to Sat, and the latest NBM's 75th percentile for highs at RDU is mid-upper 90s degrees F every day Wed-Sun, although model spread increases sharply for Sun as some models begin to dig longwave troughing over the Great Lakes region, tamping down the Southeast ridge. Regardless, these successive days of perhaps unprecedented heat may be dangerous for all populations, but particularly for those without adequate cooling and those working or exercising outdoors.

AVIATION /18Z SUNDAY THROUGH THURSDAY/

As of 200 PM Sunday...

Generally fair weather expected over the 24 hour TAF period although a few areas of marginal MVFR CIGS are possible in eastern areas this afternoon and again late tonight and early Sunday along with some marginal LLWS across the northern and western Piedmont tonight as a low level jet develops.

A backdoor cold front that moved into central NC last night and supported the development of areas of low stratus around daybreak this morning is washing out. The stratus has dissipated but a field of SCT to BKN fair weather cumulus clouds with bases of 3-4kft has developed across the eastern Piedmont and Coastal Plain this afternoon. These clouds will expand west over during the mid to late afternoon and then dissipate toward sunset. Another period of IFR to MVFR stratus is possible late tonight through just after daybreak Monday. Hard to determine how widespread the low clouds will be but they will be favored across the Sandhills (including KFAY) as well as the southern Coastal Plain and eastern Piedmont (including KRWI and KRDU). Sky conditions should improve by mid to late morning as patches of mid and high clouds spread across the area.

Surface winds continue to veer around to mainly southeast to southwesterly this afternoon at 6 to 10kts with the few gusts to around 16kts. Winds will stay up this evening and overnight and while the gusts will be less common a fairly steady south to southwest wind at 6 to 10kts is expected overnight, with the strongest winds across the northern and northwestern Piedmont (including KINT, KGSO, and KRDU). With mixing, southwest winds will range from 8 to 12kts on Monday with gusts of 16 to 22kts). A strengthening southwesterly low level jet will develop overnight with the strongest flow across northwestern areas. While not technically true LLWS as the boundary layer will generally remain mixed, there could be some marginal LLWS-like impacts overnight near the KINT and KGSO terminals.

Outlook: Generally fair weather is expected through the period as a warm southwesterly flow extends across the region.

CLIMATE

All-Time Records for April

KGSO: 95 on 4/28/1915 KRDU: 95 on 4/23/1980 and 4/28/1896 KFAY: 96 on 4/12/1930

Record High Temperatures:

April 13: KGSO: 88/1930 KRDU: 89/1922

April 14: KGSO: 90/1922 KRDU: 91/1941 KFAY: 93/1922

April 15: KGSO: 90/2006 KRDU: 92/1941 KFAY: 95/2006

April 16: KGSO: 88/2002 KRDU: 92/1941 KFAY: 94/2006

April 17: KGSO: 90/1967 KRDU: 93/1896 KFAY: 92/1941

April 18: KGSO: 90/1976 KRDU: 95/1896 KFAY: 93/1941

Record High Minimum Temperatures:

April 13: KGSO: 61/2019 KRDU: 66/1930

April 15: KGSO: 65/2006 KRDU: 64/1993

April 16: KGSO: 66/2006 KRDU: 64/1912 KFAY: 69/1934

April 17: KGSO: 63/2002 KRDU: 67/1896 KFAY: 66/1921

April 18: KGSO: 66/1909 KRDU: 63/1941 KFAY: 67/2002

RAH WATCHES/WARNINGS/ADVISORIES

None.