textproduct: NWS Wilmington

WHAT HAS CHANGED

Confidence remains limited in the freezing rain potential late Wednesday night into Thursday morning, with a small window for ice accumulation and light precip rates likely to keep any impacts minor.

KEY MESSAGES

1) Cold air filtering in early Thursday morning before the rain ends may lead to light ice accumulations which could affect the morning commute, mainly on elevated surfaces and primarily north of US-76.

2) Next Frontal System Brings Much Needed Rain Wednesday

DISCUSSION

KEY MESSAGE 1: Cold air filtering in early Thursday morning before the rain ends may lead to light ice accumulations which could affect the morning commute, mainly on elevated surfaces and primarily north of US-76.

Rain will continue through Wednesday night into Thursday morning as a mid-upper shortwave and associated surface low pivot through the Southeast US. Meanwhile, surface high pressure ridging northeastward from Texas into the eastern Great Lakes will send a chilly airmass seeping down from the north from Wednesday night through Thursday. Confidence remains limited with respect to how quickly this subfreezing air will arrive and whether this will overlap with the rain for long enough to produce ice accumulations on at least the most favored elevated surfaces, like tree branches and power/communication lines. With the cold air arriving at night, it is plausible that at least a few hundredths of ice accumulation can occur on favored surfaces, mainly along and north of US-76. This may result in slick spots on bridges during the morning commute, especially if minimum temperatures on Thursday morning can reach into the upper 20s while rain is still falling. Even if rain exits before temps fall below freezing, the amount of rain anticipated leading up to the subfreezing air's arrival should wash away most or all treatment on roadways, thus leading to the potential for patchy black ice formation. Although the overall impact from any freezing rain or black ice should be minor at worst and limited to the early to mid-morning hours on Thursday, this will need to be monitored closely.

By midday, thinning clouds and increasing sunshine should boost temperatures above freezing and end the ice threat. Steady north winds and falling dew points should help to dry out most paved surfaces that are not near leftover snow piles, so even with lows expected to fall into the low-mid 20s on Thursday night, the black ice threat should be very isolated.

KEY MESSAGE 2: Next Frontal System Brings Much Needed Rain Wednesday

A cold front associated with a low pressure system will approach the area Wednesday, bringing a nice dose of widespread rain. A few isolated showers will start to creep in from the west during the overnight hours tonight, before the main swath of rain starts to set up near the I-95 corridor late Wednesday morning. This main rain shield is associated with the front itself, which will very slowly move from west to east across the area. Precipitable water kicks up to near an inch along this line, aided by some decent isentropic lift from 285-300K. The slower movement will allow for some of the better rainfall totals that we've seen in the last few months. Even so, "better" does not equate to "ideal" necessarily, as we're going to need a lot more rain to alleviate the growing drought concerns. Rainfall totals generally range from 0.75-1.10" throughout this event. We'll take what we can get.

Another piece of good news is that this should help considerably with the melting of the remaining snowpack. Most of the area should remain above freezing for the next 30+ hours.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

VFR for the majority of the 18Z TAF period. BKN cirrus ceilings have been streaming in from the west ahead of the next frontal system. Ceilings will gradually come down late tonight, with a light breeze out of the SSW. -RA should start to hover near KFLO and KLBT sometime around 03-06Z tonight, getting to KILM, KCRE, and KMYR by 08-10Z. MVFR ceilings enter the inland terminals by daybreak Wednesday morning, reaching the coastal terminals towards the end of the period. Ceilings will dip down to IFR or even LIFR at KFLO and KLBT by 15-16Z, with RA overspreading the area.

Extended Forecast...IFR to LIFR restrictions will continue for the rest of Wednesday and Wednesday night. Conditions will start to improve Thursday, reaching VFR again sometime in the afternoon. VFR through the remainder of the week.

MARINE

Through Wednesday...Southwesterly winds at 5-10 kts will increase up to 15 kts by Wednesday morning ahead of a cold front. Winds may gust up to 20 kts at times. Seas linger near 2-4 ft.

Wednesday night through Sunday.. A cold front will settle southward on Wednesday night, veering winds from southwest or west to northerly with speeds around 15-20 kts on Thursday. Winds slacken and back to southwesterly on Friday ahead of another cold front. The next surge of cold air will arrive on Friday night with another round of breezy northwest winds around 15-20 kts, which continues through Saturday before slackening again into Sunday. Seas will vary considerably in tandem with the winds, but mainly hold below 6 feet through the period. Small Craft Advisory conditions may occur for the outer portion of the coastal waters east and southeast of Cape Fear due to gusts around 25 kts and seas around 6 ft over Friday night into Saturday.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...None.