textproduct: Raleigh

WHAT HAS CHANGED

* A Frost Advisory has been issued for tonight across most of central NC.

KEY MESSAGES

As of 145 PM Monday...

1) A Frost Advisory is in effect from 1 AM to 8 AM Tuesday across much of central NC, with the exception of our far SE.

2) Cold front will bring low-end rain chances on Thursday, followed by the coldest air so far this season for the weekend.

DISCUSSION

As of 145 PM Monday...

KEY MESSAGE 1... A Frost Advisory is in effect from 1 AM to 8 AM Tuesday across much of central NC, with the exception of our far SE.

Cool surface high pressure will remain over the Southeast US through tonight, with any cloud cover associated with a shortwave disturbance remaining well to our north over the Northeast US. Given W/NW winds turning mainly calm and a stout surface inversion developing after dark, the stage should be set for ideal radiational cooling conditions tonight. Low temperatures this morning were in the mid-30s in some outlying areas (including 33F at Burlington and Siler City), and while low-level thicknesses will be about 5-10 m higher tonight, winds should be calmer given the surface high nosing farther NE into the region. So expect lows in the mid-to-upper-30s across most of central NC outside of urban areas and the far SE where they should be closer to 40. Thus issued a Frost Advisory from 1 AM to 8 AM Tuesday for all our counties except the far SE from Scotland east to Sampson counties.

KEY MESSAGE 2... Cold front will bring low-end rain chances on Thursday, followed by the coldest air so far this season for the weekend.

A cold front will sweep across central NC during the daytime Thursday. Given the antecedent dry air and modest pwat and limited prefrontal moisture advection, PoPs assoc with the fropa will remain sub-50%. For areas that do receive some rainfall, amounts will be less than 1/2 inch.

Vigorous CAA is expected behind the cold front, with H8 temps falling from around +10C pre-frontal to around -4C post-frontal by Friday night. This will be the coldest airmass so far this season. With high pressure building over the Carolinas by Sunday, low temps Sunday morning will be the coldest in this string of cold days, with at- or sub-freezing low temps expected Sunday morning which will end the growing season across central NC. To summarize post-frontal temps... look for highs in the 50s Friday through Monday, with low temps in the lower 30s Saturday morning, Sunday morning and Monday morning.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

As of 1230 AM Tuesday...

VFR conditions are generally expected over the 24 hour TAF period. There is a very low, but non-zero chance of some shallow, patchy fog overnight in the southeast. If restrictions do occur the best chance would be at FAY. Otherwise, very little to no clouds are expected today. Winds will be generally calm tonight, with light southwesterly to northwesterly winds through the day.

Outlook: VFR conditions are expected through at least Wednesday. Rain may return Thursday into Friday, bringing the next chance of sub-VFR restrictions. Gusty winds are also expected Friday after a cold frontal passage.

RAH WATCHES/WARNINGS/ADVISORIES

Frost Advisory until 8 AM EST this morning for NCZ007>011- 021>028-038>043-073>078-083-084.