textproduct: Raleigh

WHAT HAS CHANGED

* Increased Fire Danger has expired.

KEY MESSAGES

As of 255 PM Tuesday...

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

2) A second cold front is likely to bring another round of rain early next week.

DISCUSSION

As of 255 PM Tuesday...

KEY MESSAGE 1... A cold front will bring showers and isolated strong storms Wednesday and Thursday.

A slow-moving cold front will keep at least a chance of precipitation in the forecast for the next few days. Although the front extends from Lake Ontario southwest into Texas early this afternoon, the rain shield should begin to extend into the Triad after midnight tonight. After running into some drier air, Wednesday morning and early afternoon should be relatively dry before a more concentrated area of rain begins to push into the region from the west Wednesday afternoon. The heaviest rainfall and greatest chances of rain are expected overnight Wednesday into Thursday, with coverage subsiding late Thursday night. A minimal chance of showers will continue across southern counties Friday, and another wave of low pressure lifting along the front could bring a chance of showers back into the region from the southeast Friday night into Saturday. Precipitation totals could range from as low as half an inch of rain across southeastern counties to an inch and a half across the Triad between Wednesday morning and Friday afternoon.

The possibility remains for a few strong to severe thunderstorms. The limiting factor continues to be whether there will be instability to generate thunderstorms. Model soundings continue to show a capping inversion somewhere in the mid-levels of the atmosphere, although the exact layer is different depending on the particular model. If thunderstorms are able to develop, effective wind shear could be anywhere between 30-50 knots, so the environment is certainly leaning towards a high-shear, low cape (HSLC) scenario. Will continue to monitor how much instability could be realized. Instability values appear to be the highest across the west on Wednesday afternoon and across the south on Thursday afternoon. Central North Carolina remains in a general thunderstorm outlook for both Wednesday and Thursday.

KEY MESSAGE 2... A second cold front is likely to bring another round of rain early next week.

Another cold front appears likely to cross the Appalachians on Monday, bringing a second round of showers to the East Coast early next week. Several days out, there are still timing differences with exactly when the greatest rain will arrive, but right now it appears that showers could begin as early as Sunday afternoon, Monday afternoon has the highest chances, and rain should come to an end sometime Monday night.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

As of 800 PM Tuesday...

Primarily VFR conditions are forecast through Wed, though with a chance of light, probably VFR rain/showers mainly over the NC Piedmont Wed morning. Nocturnal cooling should cause sly to sswly surface winds to lessen and only infrequently gust overnight, before they strengthen and become gusty once again with daytime/diurnal heating on Wed. In the interim, a low-level jet will intensify from srn New England and the coastal Middle Atlantic sswwd and across cntl and wrn VA and NC tonight, with an associated good chance of LLWS over the NC Piedmont.

Outlook: Scattered convection and associated flight restrictions will probably move into the NC Piedmont around and especially just after 00Z Thu, then continue at times throughout cntl NC, ahead of and along a cold front and surrounding band of IFR-MVFR ceilings that will sag swd and across the forecast area on Thu. There will be another chance of showers/storms and flight restrictions with the approach and passage of another frontal system Sun-Mon.

RAH WATCHES/WARNINGS/ADVISORIES

None.