textproduct: NWS Wilmington

SYNOPSIS

High pressure will bring rain-free conditions and a slight warmup through Wednesday. A cold front will bring seasonable temperatures but no rain Thursday, and then a warmup for the weekend. A stronger cold front arrives late Sunday bringing much cooler temperatures and possibly the first freeze of the season across spots inland early next week.

NEAR TERM /THROUGH TONIGHT/

Yesterday's upper trough is well offshore and a broad, flat upper ridge covers the southeastern quarter of the country. Surface high pressure will move eastward today, reaching the coast of the Carolinas this afternoon. Expect almost 100 percent sunshine and temperatures rising into the upper 60s.

Monday evening's 00z upper air sounding at Greensboro measured 30 degree F dewpoints at 2500 feet AGL and 25 degree F dewpoints at 3000 feet. We're forecasting mixing heights to reach 3000-3500 feet this afternoon meaning we'll likely drag down a portion of that dry air, diluting our boundary layer moisture. I've adjusted forecast dewpoints a little below NBM with a 50:50 blend with the HREF. Minimum relative humidity could fall below 30 percent in spots, but fortunately for fire weather concerns there won't be any significant wind.

Calm winds and clear skies tonight should yield impressive radiational cooling. Lows should fall into the upper 30s to around 40 inland with lower to mid 40s limited to the coast. Normally colder locations (pocosins and peat soils mainly across SE North Carolina) could dive several degrees colder with frost possible.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Center of high pressure right along the coast early Wed will shift farther off the coast Wed through Wed night. This will allow a southerly return flow to develop and as the gradient tightens with approaching cold front, SW winds should increase and become gusty. This will be fairly short-lived as we remain in a fairly progressive flow with front dropping south by Thurs morning and a shift to northerly flow into Thurs. The front moves through lacking much in the way of moisture with soundings showing any moisture below 5k ft and therefore do not expect much more than some clouds and a wind shift with this one. High pressure will reach down behind the front as the center migrates from the Ohio Valley to the NC/VA line by Fri morning.

Temps Wed will be on the warmer side with readings into the mid 70s in a southerly return flow while Thurs will see a drop in temps back toward normal, around 70 behind a weak cold front. Overnight lows will be in the mid 40s to around 50 near the coast, but Thurs night may see some lower 40s inland.

LONG TERM /FRIDAY THROUGH MONDAY/

As the high moves off the coast to the north of local area on Fri, it will continue to ridge back into the central Carolinas as a weak coastal trough develops on Fri. Could see potential for a shower moving on shore Fri aftn as an onshore to southerly return flow develops, but not much energy aloft as flow remains rather flat. The southerly flow will bounce temps back into the mid 70s. The southerly return flow should last a bit longer this time as we head into the weekend with above normal temps and increasing dewpoints. Slightly better upper dynamics should produce a greater chc of shwrs on Sat, but looks like best shortwave energy will remain north and west on Sat. GFS keeps a more unsettled weekend with more in the way of clouds and potential for shwrs, especially heading into the latter half of the weekend into Mon as mid to upper trough digs south pushing a stronger cold front through. Latest guidance shows potential for temps to push 80 inland over the weekend with a sharp drop in CAA for Mon whereby temps may not reach 60 and could see widespread 30s for overnight lows early next week with possibly our first freeze inland in spots.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

There is high confidence for VFR conditions over the coming 24 hours. Northwesterly winds will turn northerly after 12z. A weak seabreeze may develop at the KMYR and KCRE airports late this afternoon turning wind directions onshore. Although the HRRR and AWCGFA models both develop areas of fog late tonight, the atmosphere appears it will remain too dry to support fog.

Extended Outlook....VFR conditions should prevail through the period. Brief IFR/MVFR conditions are possible in early morning ground fog Thursday and Friday.

MARINE

Through Tonight...With low pressure now well out to sea, attention is shifting to an area of high pressure approaching from the west. Breezy northwest to north winds this morning could gust over 20 knots before 11 AM, but should diminish substantially this afternoon as the high reaches the coast. Light and variable winds this evening through midnight should turn south to southwesterly after midnight as the high moves offshore.

Seas should consist of 2-4 ft short period waves this morning, diminishing to 2-3 feet this afternoon and down to 1-2 feet this evening.

Wednesday through Saturday...Center of high pressure right along the coast early Wed will shift farther off the coast Wed through Wed night. This will allow a southerly return flow to develop and as the gradient tightens with approaching cold front, SW winds should increase and become gusty. May see gusts up to 25 kts, but it looks like we should remain below SCA thresholds and seas will only bump up to 3 to 4 ft Wed night.

A cold front will drop down Thurs with a shift to northerly winds with gusts up to 20 kts. A fairly progressive flow will continue with high pressure to the north shifting off the NC/VA coast by Thurs night with an onshore return flow over the local waters. A weak coastal trough will develop early Fri before southerly flow takes over Fri aftn into the weekend. Seas will basically range from 2 to 4 ft.

ILM WATCHES/WARNINGS/ADVISORIES

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