textproduct: NWS Wilmington

SYNOPSIS

High pressure brings chilly weather tonight into Wednesday with seasonable weather for the late week period. Low pressure moving west-to-east across the region will bring rain Friday night and Saturday. Seasonable and rain-free conditions are then expected heading into early next week.

NEAR TERM /THROUGH WEDNESDAY/

A bone dry Canadian airmass covers most of the eastern United States, brought southward by the northwesterly flow between 970 mb low pressure over eastern Quebec and a high centered over eastern Texas. Precipitable water values are barely 0.2 inches with dewpoints in the mid-upper teens this afternoon. Winds should become calm after sunset with nearly ideal radiational cooling anticipated. Forecast lows are definitely on the chilly side with mid 20s expected for most locations. Normally cold southeastern NC locations with peat soil (like Holly Shelter Gameland) could dip into the 15- 20 degree range tonight.

High pressure should begin to move eastward along the Gulf coast Wednesday. Surface winds should turn westerly, and even southwesterly along the coast during the afternoon, with sunny skies continuing. Forecast highs range from the upper 40s for the Brunswick County beaches to the lower 50s across the Pee Dee region.

SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/

Surface high pressure will move slowly east from the Gulf to FL during the course of the short term. In the mid levels tough remains over the eastern U.S. but de-amplifies. Forecast soundings show some cirrus level moistening and with a 250mb jet spilling SE across the Appalachians this seems plausible. Tough to say when this layer acquires enough opacity to have an effects on temperatures. Currently it appears to take place after the short term so both nights will have very similar lows. Prefrontal trough pushes through right at the end of the period.

LONG TERM /FRIDAY THROUGH TUESDAY/

Low pressure nearly circular over NE TX on Friday will elongate west- to-east Saturday as it crosses our longitude. This will mean a slightly slower increase in clouds on Friday, which now looks mostly rain-free until 03Z or so. The low's change in geometry will also lead to weaker advective processes compared to yesterday which should translate into less of the drought-releif that looked possible yesterday. There has also been a southward shift in the forecast track opening up a N/S gradient in expected rainfall, highest south. Rain chances taper quickly Saturday with the exit of the low and cloud cover will follow suit soon thereafter. There is no push of cold air behind this system as low amplitude ridging develops in the nations midsection leading to a seasonable end to the period.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

VFR conditions will continue over the next 24 hours.

Extended Outlook...Low level wind shear could develop Wednesday night near the base of a westerly low level jet. MVFR to IFR ceilings and MVFR visibility are likely in rain late Friday night through Saturday as low pressure moves to our south.

MARINE

Through Wednesday...Chilly northwest winds cover a good portion of the East Coast between Canadian high pressure centered over Texas and a 970 mb low over eastern Quebec. Winds should continue to slowly diminish and should back westerly on Wednesday. Seas should average 2 feet or less. No advisory headlines will be required.

Wednesday night through Sunday... W to NW flow early in the period on the NE side weak high pressure progressing across the Gulf Coast. Pre-frontal trough and then weak front itself push through Thursday night or Friday increase winds and seas. Have held off on SCA as it's still a few periods out, the low coming from the west looks slower, and the southward shift of the track could affect where the gradient gets tightest. There are also some stability arguments to be made with SST's so cool so have relegated SCA to the HWO only. As the low moves by Sat winds veer from NW to NE decrease at first as the low passes by, then increase again with the push of the high from the north. Most of the period will be dominated by wind waves. After the low passes by however a ENE swell will start to materialize.

ILM WATCHES/WARNINGS/ADVISORIES

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