textproduct: Raleigh

WHAT HAS CHANGED

As of 310 PM Saturday...

* Confidence is increasing in a multi-day early-season heat wave next week.

KEY MESSAGES

As of 735 PM Saturday...

1) A backdoor cold front will continue to move southward tonight. The isolated showers that have developed across the western Piedmont should dissipate well before midnight.

2) Fire weather concerns will persist through next week, with continued dry weather.

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

DISCUSSION

As of 735 PM Saturday...

KEY MESSAGE 1... A backdoor cold front will continue to move southward tonight. The isolated showers that have developed across the western Piedmont should dissipate well before midnight with some clouds lingering along with near normal temperatures.

A backdoor cold front is slowly making its way through the Carolinas this evening. The presence of a weak wave of low pressure along this front along with moisture pooling (evident in RAP analysis PW fields) has aided in the development of some widely scattered showers across the western Piedmont. KEXX saw 0.02 earlier this evening with one of these showers and undoubtedly similar amounts were seen between KINT/KGSO where a shower managed to slide through the area. Elsewhere it has remained dry, and will remain as such for the rest of the night. The few showers that remain on radar should gradually weaken well before midnight as we lose daytime heating and instability.

The front will stall overnight and with increased moisture in the vicinity of the front, coupled with increased easterly winds, expect cloud cover to increase across the western Piedmont late tonight. Winds in the 5-10kt range would support stratus vs fog so we will leave fog out of the forecast for tonight. As for temps, look for lows to fall into the low/mid 50s.

KEY MESSAGE 2... Fire weather concerns will persist through next week, with continued dry weather.

Very dry conditions will persist through next week. Winds are projected to hold below criteria for red flag warnings, as gusts should peak at around 15 mph with infrequent afternoon gusts up to 20 mph. But fuels remain extremely dry, and little to no rain is expected in the region through the next several days, with minimum RH values forecast to be in the 2530% range Tue through Fri. National forestry officials are indicating a moderate to high risk for significant fire potential early next week, highest from the NC mountains through the western Piedmont. A statewide burn ban remains in effect for all of NC until further notice. All burning, including with previously-issued permits, is prohibited.

KEY MESSAGE 3... Dangerous heat wave possible next week, with several consecutive very hot days. Near record temperatures possible Tue through Sat.

Concern is increasing regarding the potential for a dangerous early- season heat wave across the Carolinas next week. Mid level ridging now over Mexico and the Gulf will steadily build and amplify across the Southeast states through next week as a Bermuda surface ridge remains in place, deflecting 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 as much as 50 m into next Sat. Periods of clouds remain possible, including on Fri when deterministic models take a weak Baja-source shortwave trough across the region. But, overall, sunshine will 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, and the latest NBM's 75th percentile for highs at RDU is 95-100 degrees F every day Wed-Sat. 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 /00Z SUNDAY THROUGH THURSDAY/

As of 735 PM Saturday...

The passage of a weak backdoor cold front (and the presence of a weak area of surface low pressure along this front) has supported the development of a few showers across the western Piedmont as of early evening. Showers have threaded the needle between INT/GSO and managed to avoid the remaining terminals outright. Any lingering showers that develop should be confined to the INT/GSO vicinity and quickly dissipated after 02Z. Dry weather thereafter.

The aforementioned front will stall across the Carolinas overnight. Weak moisture pooling near the front will support the development of MVFR stratus across the western Piedmont, potentially dropping briefly to IFR around daybreak but this should be short lived. Also, there should be a brief increase in the winds later tonight as the BL briefly deepens as the 925mb front slides to our south. Expect winds to gradually veer through the day tomorrow with breezy southerly winds developing by late morning.

Outlook: Morning stratus is possible Mon in a return flow regime, most favored at GSO/INT and RDU. VFR should otherwise prevail through Thursday.

CLIMATE

Record High Temperatures:

April 11: KFAY: 90/2001

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

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

RAH WATCHES/WARNINGS/ADVISORIES

None.