textproduct: Raleigh

WHAT HAS CHANGED

As of 210 AM Thursday...

* No major changes to the weekend storm system. Confidence remains high in widespread beneficial rainfall this weekend, mainly from late Sat night through Sun night.

KEY MESSAGES

As of 210 AM Thursday...

1) We'll have low humidity over much of the area today, but wind gusts are likely to hold below fire weather thresholds.

2) Steady light to moderate rain expected late Sat night through Sun night. While much of the rainfall will be beneficial given the current drought conditions, isolated pockets of heavier rain could lead to standing water on roads in some locations.

DISCUSSION

As of 210 AM Thursday...

KEY MESSAGE 1... We'll have low humidity over much of the area today, but wind gusts are likely to hold below fire weather thresholds.

As yesterday's cold front settles to our S today, dry surface air filtering in from the N combined with temps reaching highs in the 50s to near 60 most places will lead to low relative humidity over central NC today. This will especially be the case over the Sandhills and S/W Piedmont, where minimum RH is likely to be in the 18% to 25% range. While it will be breezy today with winds from the NW, gusts are expected to be no higher than 20-25 mph, below thresholds that might bring about significant fire weather concerns. However, forestry officials will be consulted this morning as we further assess weather and fuel conditions, especially given the paucity of rainfall yesterday.

KEY MESSAGE 2... Steady light to moderate rain expected late Sat night through Sun night. While much of the rainfall will be beneficial given the current drought conditions, isolated pockets of heavier rain could lead to standing water on roads in some locations.

A strong mid/upper level short-wave will move across the southern Plains Saturday before moving across the Deep South/Southeast Sunday into Monday. This system will feature a swly surge of anomalous PWAT (up to ~1 to 1.25 inches; ~200 to 250 % of normal) into central NC by Sunday afternoon.

The GFS/GEFS is still the slowest solution with the upper wave diving the further south compared to the EPS/GEPS. However, given the anomalous moisture flux expected over our area, solid isentropic- driven rainfall is likely even if the GFS/GEFS solution is realized. As such, we have pretty high confidence at this point in a beneficial rain for majority of central NC during this period. The 12Z GEFS did also pivot some higher QPF further up into central NC (previous runs kept higher totals to our south). Even the 5th percentile across all ensembles paints at least a few tenths of an inch of rain across central NC. All of this adds confidence to a solid rain event for our area. While this rain will be beneficial in most areas considering the ongoing dry conditions, the latest LREF shows a nearly 50% chance of >1" in under 24 hrs over portions of the Piedmont. Locally higher rainfall totals could lead to some minor urban flooding and water on roads in some locations, but no significant or widespread flooding is expected.

Latest guidance continues to trend towards a faster retreating high to our north. As such, this will favor an in-situ CAD type. Daytime highs may warm a bit more than previously thought (highs in upper 40s to low 50s NW to around 60 SE).

AVIATION /06Z THURSDAY THROUGH MONDAY/

As of 1220 AM Thursday...

VFR conditions will hold across central NC for the next 24 hours, with high confidence. A backdoor cold front will settle to our S through today as high pressure builds in from the NW and N. A period of bkn mid clouds based at 12k-15k ft AGL is expected across the area today, mainly from 14z to 23z, but otherwise only sct mid and high clouds are expected. Sfc winds will be from the NW today, shifting to NNW and N by sunset, with speeds generally under 10 kts but will be 10-13 kts gusting to 17-22 kts from mid morning through this afternoon.

Outlook beyond 06z Fri: VFR conditions will dominate through Sat, then a trend to sub-VFR conditions is likely Sat night, persisting through Sun night, with periods of rain. Conditions should return to VFR Mon, but with gusty winds. -GIH

RAH WATCHES/WARNINGS/ADVISORIES

None.