textproduct: Raleigh

WHAT HAS CHANGED

As of 732 PM Friday...

* Updated Aviation discussion.

KEY MESSAGES

As of 223 PM Friday...

1) A cold front will move through the area late this afternoon into the evening, bringing scattered showers and thunderstorms between about 5 PM and 8 PM followed by lighter patches of rain through about 1 AM.

2) Increased fire danger for Saturday.

3) Widespread frost is likely early Sunday morning, with a few spots possibly dropping low enough for a light freeze.

4) Dry weather with steadily increasing temperatures through mid/late week. A potential shift into a wetter pattern is possible late week/next weekend.

DISCUSSION

As of 223 PM Friday...

KEY MESSAGE 1... A cold front will move through the area late this afternoon into the evening, bringing scattered showers and thunderstorms between about 5 PM and 8 PM followed by lighter patches of rain through about 1 AM.

While most of the t-storms invof the front between 5-8 PM will be sub-severe, one or two of them could briefly become stronger with a small chance of hail and gusty winds. The risk for stronger storms is very limited though due to marginal instability, but non-zero chances due to 30+ kts of shear, esp north near the VA border. As the evening progresses, the thunderstorms will give way to patchy light rain that could last for several hours from the mid-evening to early overnight hours. Rainfall amounts will generally be 1/4 inch or less with locally higher totals where thunderstorms occur. Behind the front, winds will shift to the north and northeast, becoming gusty and advecting in noticeably cooler air through the night. Lows tonight will range from the upper 30s NW and Triad region to mid 40s elsewhere.

KEY MESSAGE 2... Increased fire danger for Saturday.

With sfc dewpoints dropping into the teens to lower 20s on Saturday, RH values will bottom out between 18 and 25% during the afternoon across much of central NC. Meanwhile, wind gusts of 25-30 mph are possible early Saturday, but are expected to diminish some during the afternoon as the pres gradient relaxes as high pressure continues building eastward. Since the wind gusts are expected to drop below RFW criteria by the time the RH meets criteria in the afternoon, we will forego issuing a RFW attm and instead go with an increased fire danger statement for all of central NC. That IFD statement is in effect between 11 AM and 8 PM on Saturday.

KEY MESSAGE 3... Widespread frost is likely early Sunday morning, with a few spots possibly dropping low enough for a light freeze.

A large area of high pressure moving in from Canada will settle over the region by around sunrise Sunday. Overnight temperatures are expected to fall into the upper 20s to mid-30s, which will produce frost in many areas and freezing conditions in the usual colder spots that drop below 32. Its worth noting that the regions official frost and freeze alert program doesn'tt begin until April 1st. Until then, the risk will still be mentioned in forecasts, but formal frost or freeze advisories and warnings will not yet be issued.

Key Message 4: Dry weather with steadily increasing temperatures through mid/late week. A potential shift into a wetter pattern is possible late week/next weekend.

Mid/upper level ridging will remain in place across much of the eastern CONUS to start the week. This will persist through Wednesday before it gradually migrates offshore Thursday into Friday. This will open the door to a series of weak shortwaves which will traverse the western periphery of the ridge. Moisture return within this regime will be modest with best moisture transport west of the mountains to start, although this axis will gradually pivot eastward by late in the week. All in all precip chances remain low or near zero through mid week, with a gradual increase Thursday and Friday. Ensemble mean QPF remains relatively low, with no drought-busting precip events on the horizon.

Following below normal temps this weekend, temps will be above normal (if not well above normal) next week with highs ranging from the mid 70s Monday to the mid 80s Wednesday. Forecast highs are a bit more uncertain later in the week given the potential for increased cloud cover and precip, and could conceivably retreat into the upper 60s/lower 70s if precip does in fact materialize.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

As of 731 PM Friday...

Showers and a few tstorms have popped up across northern areas this evening along and just ahead of the cold front which has just cleared KRWI/KINT/KGSO. Expect some additional isolated convection to possibly impact KRDU/KFAY/KRWI the next few hours. Otherwise, post-frontal light rain will spread north to south through ~08Z Saturday morning. A period of IFR/MVFR ceilings will accompany the post-frontal light rain, generally scattering to VFR from ~12 to 15Z. Lastly, expect gusty nnwly winds to peak overnight/early Saturday morning before subsiding mid afternoon.

Outlook: Patchy fog and/or stratus will be possible amid a return flow regime, and associated increase in low-level moisture over cntl NC, by Tue morning.

RAH WATCHES/WARNINGS/ADVISORIES

None.