textproduct: Raleigh

WHAT HAS CHANGED

* No major changes were made to the going forecast.

KEY MESSAGES

As of 133 PM Saturday...

1) Unseasonably hot, near record temperatures today.

2) Noticeably cooler Sunday with little if any wetting rain.

3) Patchy frost possible Tuesday morning. Otherwise, a warming trend mid to late week is expected with little rain chances till end of the extended period.

DISCUSSION

As of 133 PM Saturday...

KEY MESSAGE 1... Unseasonably hot, near record temperatures today

Temperatures as of 1pm are already running in the upper 80s to some low 90s across central NC. Temperatures will continue to climb up until the early evening, likely tying or breaking record highs today. Some afternoon fair weather cumulus is favored but will not be enough to limit the unseasonably hot weather.

Dewpoints have continued to mix out this afternoon, similar to the past few days. Readings are presently in the middle 40s over the Piedmont. We adjusted the forecast to account for these critically low RH levels in the upper teens to middle 20s. Remember, the statewide burn ban issued by the NCFS remains in effect.

KEY MESSAGE 2... Noticeably cooler Sunday with little if any wetting rain.

A strong cold front will push through during the morning hours. Just immediately behind the front, NW winds of 15 to 20 mph will reach gusts in the 25 to 30 mph range, with even some infrequent gusts to 35 mph over the Piedmont. As such, highs will likely be felt during the early morning hours over the NW Piedmont and mid-morning hours in the southeast with upper 60s NW to low/mid 70s SE. Once the front moves through, we will see temperatures briefly fall into the mid 50s to low 60s before briefly recovering late in the day in the low to mid 60s.

As for rain chances, not much has changed compared to the prior forecast package. The 12z HREF has continued the low-end rain amounts, with only a few hundredths of an inch at best over most areas, with little to none over the southern Piedmont and Sandhills. The best chance of rain will be during the morning to early afternoon. Some enhanced frontogenesis along the front over the northeast Piedmont and northern Coastal Plain should favor some isolated amounts of a tenth of an inch of rain, in line with the latest ensemble guidance. But overall, this is not a wetting rain to limit fire potential. The NW wind gusts over the western Piedmont will combine with dewpoints crashing into the lower to mid 20s post- frontal, resulting in RH in the 20-25 percent range late Sun afternoon. This will promote rapid fire spread, so the public is again urged to heed the NCFS fire ban.

Winds should turn calm Sun night, resulting in some colder lows from the upper 30s to low 40s, in line with the latest statistical guidance.

KEY MESSAGE 3... Patchy frost possible Tuesday morning. Otherwise, a warming trend mid to late week is expected with little rain chances till end of the extended period.

A strong sfc high is expected to traverse over the Mid-Atlantic Monday into Tuesday. This will lock in nely flow Monday night with low-level thicknesses generally ranging between 1300 to 1330 m. Statistical guidance continues to suggest possible near to just below freezing lows in our traditionally cooler spots along the NC/VA border. There is some uncertainty wrt to how much mixing might persist overnight, but overall looks to be a decent signal for at least frost producing temperatures to be reached Tuesday morning.

After a few cooler afternoon Tuesday and Wednesday (highs in the upper 60s to mid 70s), the offshore ridge will re-establish itself across the southeast pumping temps back up into the mid to upper 80s by Friday/Saturday.

Precipitation wise, some high-res guidance is suggesting a few isolated showers may accompany the passage of an upper trough Monday afternoon. However, forecast soundings appear to be a bit too dry in the lower levels. As such, virga seems more favorable than measurable rain at this point, if anything at all.

Ensembles remain dry through early Friday, with some signal for better rain chances sometime in the late Friday to Sunday period.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

As of 750 PM Saturday...

VFR conditions are likely to hold through the next 24 hours across central NC terminals, although a passing cold front is expected to bring a period of bkn-ovc clouds just above MVFR thresholds (topped by mid and high clouds as well), with this lower deck mainly very late tonight through Sun morning. We'll also have some wind concerns aloft: A nocturnal inversion plus a low level SW jet at 1500-2000 ft AGL over N and E NC may bring borderline low level wind shear conditions to RDU/RWI/FAY this evening/tonight, mainly 02z-09z. Then, as the front pushes WNW-to- ESE through central NC during roughly 08z-14z, winds will shift to be from the NW, sustained 12-17 with frequent gusts to 22-30 kts, lasting at least into the mid afternoon, with a slight decrease in speeds toward the end of the TAF period. Clouds will clear out between 18z (in the NW) to 22z (in the SE).

Looking beyond 00z Mon, wind speeds will continue to lower with diminishing gusts by mid evening. VFR conditions are likely to hold through Thu, under high pressure.

CLIMATE

All-time records for April:

KGSO: 95 on 4/28/1915 KRDU: 95 on 4/23/1980 and 4/18/1896 KFAY: 96 on 4/12/1930

Record High Temperatures:

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

April 24: KRDU: 93/1960 KFAY: 95/1925

Record High Minimum Temperatures:

April 18: KRDU: 63/1941

April 24: KGSO: 62/2004

RAH WATCHES/WARNINGS/ADVISORIES

None.