textproduct: Raleigh

WHAT HAS CHANGED

As of 1215 PM Monday...

* Higher confidence in weekend storm

KEY MESSAGES

As of 1215 PM Monday...

1) Very cold temperatures are expected tonight and again Tuesday night with lows in the teens to low 20s.

2) Below normal temperatures for much of the week, with record cold high temperatures possible on Sunday.

3) A significant winter storm is possible this weekend.

DISCUSSION

As of 1215 PM Monday...

KEY MESSAGE 1... Very cold temperatures are expected tonight and again Tuesday night with lows in the teens to low 20s.

A secondary cold front will move through the region late tonight and early Tuesday. Cold high pressure over the Central Plains will settle into the TN valley on Tuesday and be centered over central NC Tue night into early Wednesday. This pattern will favor a continued cold stretch into the middle of the week. Very cold temperatures will be felt the next few nights, coldest on Tuesday night. Lows Tuesday night will range from the mid to upper teens in most places. Some outlying areas could dip easily into the lower teens under strong radiational cooling. Temperatures will start to moderate around midweek.

KEY MESSAGE 2... Below normal temperatures for much of the week, with record cold high temperatures possible on Sunday.

The warmest day out of the next seven appears to be Thursday, with temperatures in the 50s, and even these temperatures are 'only' near normal (low to mid 50s). The rest of the week shows below normal temperatures, and temperatures may not even rise above freezing on Saturday and Sunday. The coldest temperatures are forecast on Sunday night, with temperatures as low as the single digits.

KEY MESSAGE 3... A significant winter storm is possible this weekend.

With any impacts from this storm at least four days out, will not attempt to get into specifics at this time. However, it appears that a front will be nearly stationary along the Gulf coast through much of the weekend, which should allow for both lift and precipitation. Strong high pressure moving from the Northern Plains across the Great Lakes into the Northeast would be the continual source for cold air with northerly flow (unlike yesterday when less cold air was available). While precipitation could move into the region as early as Thursday and remain as long as Monday, Saturday and Saturday night currently appear to have the highest chances for any precipitation. Snow and freezing rain are both possibilities, although again, it would be unwise to get into specifics at this time. There is a chance that precipitation continues into Sunday, and if it does, forecast temperatures below freezing in all locations would automatically mean that a precipitation type other than liquid rain occurs. The forecast will likely change between now and the weekend.

AVIATION /18Z MONDAY THROUGH FRIDAY/

As of 1215 PM Monday...

There is reasonably high confidence in VFR conditions through the 24- hour TAF period. W to SW winds this afternoon and this evening of 10 to 20 kt will become light tonight before switching out of the north overnight with a cold frontal passage. Ahead of the cold front, there is a very low-end chance of some sub-VFR visibilities near FAY/RWI. Most of the guidance shows limited fog potential, so confidence is low. WNW winds Tue will range from 5 to 10 kt.

Outlook: VFR should prevail most of Wed, Thu, and Fri, though cannot rule out a stray shower in the Triad early Thu. A potential winter storm could bring a wintry mix and adverse aviation conditions Sat into Sun. Confidence on details is low but bears watching.

RAH WATCHES/WARNINGS/ADVISORIES

None.