textproduct: Raleigh

WHAT HAS CHANGED

As of 615 AM Tuesday...

* No major changes to the forecast, updated aviation discussion.

KEY MESSAGES

As of 1255 AM Tuesday...

1) Patchy frost possible tonight/tomorrow morning and Thursday morning, but this frost potential could be mitigated by wind tonight and clouds tomorrow night.

2) Worsening drought conditions from a dry forecast, and the prolonged influence of continental air and low relative humidity, will increase fire weather concerns through the weekend.

DISCUSSION

As of 1255 AM Tuesday...

KEY MESSAGE 1... CAA over the next 24-30 hours will set the stage for chilly temps tonight and early Wednesday morning. Our current forecast shows lows Wednesday morning from the low-mid 30s along and north of I-85 and esp along the VA border, with lows 35-40 elsewhere across central NC. Ordinarily these temps would suffice for patchy frost, which would necessitate a frost advisory tonight. However, we are expecting NE winds to remain elevated tonight along with dwpts falling through the 20s, which in this case may actually limit the frost potential. The locations with the best chance to see frost tonight will be those mentioned above with low-mid 30s (along and north of I-85 and near the VA border). Will closely monitor and the day shift can issue a frost advisory should the trends support that.

Cold readings are expected again Thursday morning with lows near to perhaps a degree colder than Wednesday morning. However this time we'll have additional cloud cover which would yet again limit frost potential. It's worth noting that if these clouds don't materialize, or if there are ample breaks in them, we could see patches of frost set up Thursday morning, esp in the colder locations north near the VA border and west of the Triangle.

KEY MESSAGE 2 ... Worsening drought conditions from a dry forecast, and the prolonged influence of continental air and low relative humidity, will increase fire weather concerns through the weekend.

The prolonged presence and influence of the cP surface high/ridge through the week will favor both a dry forecast and min RH values below 45% every day of the forecast period, lowest and mostly in the 20s percent Tue-Wed. While associated surface winds will be relatively light through most of the forecast period, they will be relatively strongest from the northeast at 10-15 kts and with gusts to around 20 or so kts Wed, when the MSL pressure gradient around the anomalously strong surface high will be maximized.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 615 AM Tuesday...

VFR conditions will prevail through the period as a dry cold front crosses the region. Current high ceilings will scatter out from northwest to southeast this afternoon and evening, leading to mostly clear skies (SKC) overnight. No visibility restrictions are expected.

The main forecast concern is the wind shift behind the front. Light morning winds will turn north-northeasterly between today, with occasional gusts up to 20kts through the afternoon. Winds will diminish and veer slightly more toward the northeast after sunset.

Outlook: VFR conditions are expected to persist through the early part of the upcoming weekend.

RAH WATCHES/WARNINGS/ADVISORIES

None.