textproduct: Raleigh

WHAT HAS CHANGED

* Updated the aviation discussion to reflect the 12z TAF forecast.

* Increased winds and wind gusts and lowered relative humidity values for this afternoon based on latest forecast guidance.

* Increased chances for showers and storms Thursday.

KEY MESSAGES

As of 220 AM Tuesday...

1) Recent green-up in fuels will help mitigate widespread significant fire behavior today despite gusty southwest winds and dry conditions.

2) A cold front will bring showers and isolated strong storms Wednesday and Thursday.

DISCUSSION

As of 220 AM Tuesday...

KEY MESSAGE 1... Recent green-up in fuels will help mitigate widespread significant fire behavior today despite gusty southwest winds and dry conditions.

Between the sub-990mb surface low just south of the Hudson Bay and lingering broad surface high pressure over the western Atlantic, enhanced flow aloft is expected to mix down to the surface with daytime heating this morning into the early evening hours. Point soundings suggest sustained winds 15 to 20 mph and gusts 20 to 30 mph will become frequent across the area, strongest in the northern Piedmont. Momentum at the top of the mixed layer suggests infrequent gusts of around 35 mph can't be ruled out.

Moisture advection will be limited today to mainly the Coastal Plain as Atlantic moisture begins to advance northward, but Gulf moisture will remain delayed moving into the Carolinas and primarily directed into the Lower MS Valley today. This should allow RH values to drop below 30% over the Piedmont and may drop as low as low/mid 20s by mid afternoon. These forecast adjustments will likely result in several hours of IFD meteorological criteria (RH < 30% and gusts > 25 mph) to be met along and north of the I-85 corridor. Despite these meteorological parameters and ongoing extreme drought, coordination with the NCFS yesterday reported that fuels have greened up sufficiently to reduce widespread fire danger concerns.

A reminder: While the burn ban has been lifted in 81 counties in NC by the NCFS, it remains in place for Forsyth, Guilford, Davidson, Randolph, Alamance, Chatham, Stanly, Montgomery, Moore, Anson, Stokes, Rockingham, Davie, Rowan, Iredell, Cabarrus, Gaston, Mecklenburg and Union counties.

KEY MESSAGE 2... A cold front will bring showers and isolated strong storms Wednesday and Thursday.

The mid-week forecast concern revolves around an approaching cold front expected to bring a round of showers and isolated strong storms to the region Wednesday through Thursday. Winds will be the first noticeable impact, becoming gusty early Wednesday morning. These initial gusts of 25-30 mph will be concentrated mainly across the NW Piedmont before expanding eastward as the front nears; by Wednesday afternoon, the entire CWA could see infrequent wind gusts up to 25 mph. While the pressure gradient relaxes slightly, breezy conditions of 10-20 mph will hold on overnight and through Thursday, with locally stronger gusts occurring along the frontal boundary itself.

PoPs will begin to increase early Wednesday morning in the NW Piedmont. This initial activity is expected to be relatively light and scattered, with isolated showers focused primarily across the northern Piedmont. A second, more potent wave associated with the frontal boundary will arrive later, bringing a more organized round of showers and storms. Forecast confidence remains centered on the potential for instability; if enough surface heating occurs, some afternoon storms could become strong, with damaging wind gusts being the primary threat. Total QPF amounts for this event, spanning Wednesday morning through Friday evening, are currently between 0.25" and just over an inch, providing a beneficial soaking for most of the area. Lingering moisture will stick around Friday and possibly Saturday with max PoPs at 30%, but expect more clouds than rain. As high pressure pushes in from the west expect clouds and lingering showers to shift out of the area Saturday afternoon and evening.

Temperatures will vary from upper 70s to mid 80s Wednesday, then after the cold front passes through highs on Friday will only be in the mid 60s to near 70. Over the weekend, temperatures will range from mid 70s to low 80s as high pressure centers over NC.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 640 AM Tuesday...

VFR conditions will prevail through the TAF period. Gusty southwest winds are expected to develop with daytime heating (20 to 30 kts) with moderate low-lvl turbulence expected around the Triad terminals, given sufficient sunshine. Fair weather cu around 5 to 8 kft will likely develop by this afternoon, mostly around FAY and RWI where slightly richer low-lvl moisture will be in place.

Outlook: Decaying storms from the TN Valley may bring light, mainly stratiform rain, to the Triad terminals early Wed morning, but prevailing sub-VFR conditions are not expected. A better chance for sub-VFR conditions, showers and storms, and continued gusty conditions are expected Wed night through Thurs as a cold from traverses the region.

RAH WATCHES/WARNINGS/ADVISORIES

None.