textproduct: NWS Wilmington

WHAT HAS CHANGED

Issued a Frost Advisory for the coastal areas, and plan to maintain the current Freeze Warning for the inland areas. The aviation discussion was updated for the 18Z TAFs.

KEY MESSAGES

1) Dry weather will persist for most of the upcoming week. Below normal temperatures with frost and/or freeze conditions are expected each night and early morning through the middle of the upcoming week.

DISCUSSION

KEY MESSAGE 1...Dry weather will persist for most of the upcoming week. Below normal temperatures with frost and/or freeze conditions are expected each night and early morning through the middle of the upcoming week.

The mid/upper trough will deamplify but linger across the eastern U.S. through at least Tuesday with the axis shifting toward the east as a well amplified ridge extends from the Gulf Coast across the OH Valley and into the Great Lakes region. Moisture will remain very limited given this pattern especially with the surface high also helping to suppress any return flow through the upcoming week. This period of dry weather will add to the rainfall deficiencies the area has experienced so far this year. ILM's departure from normal is more than 11 inches, Florence and Lumberton more than 10 inches, and more than 20 inches in the Myrtle Beach area!

In addition to the dry conditions the swath of cold air supported by high pressure over the MS valley will result in freezing temperatures tonight into early Sunday morning. Coastal areas are expected to be slightly warmer, but will experience areas of frost, especially away from the beaches. As a result, plan to maintain the current Freeze Warning for inland areas, and introduce a Frost Advisory for the remaining coastal areas. Frost looks likely again Sunday night into early Monday morning, with a few spots reaching freezing again. Frost is a good bet late each night into the early morning, especially inland areas through the middle of the upcoming week.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

High confidence in VFR conditions prevailing through the TAF period. While water vapor imagery shows a large swath of dry area in this part of the mid/upper trough there is just enough lower level moisture to squeeze out some diurnal cumulus. Cloud bases are expected to be above 5kft through the afternoon, with SKC conditions developing by early this evening. Some sporadic gusts to 20 kt+ are possible, especially at KILM, with speeds diminishing with the loss of heating by early this evening. Light flow and mostly clear skies are expected during Sunday.

Extended Outlook...High confidence in VFR conditions prevailing Sunday afternoon through Thursday.

MARINE

Through Thursday...High pressure will ridge into the area from the MS Valley through Sunday maintaining manageable offshore flow. The limited fetch will create a large range in seas from the inshore waters to the offshore waters during this time. The high will slowly shift toward the OH Valley during Monday which will equate to some veering of the flow. As the high shifts farther east N-NEly winds will become established with the stronger part of the fetch becoming situated across the SC/GA/FL waters by mid-week. Low pressure far off the GA/FL coast and the high settling across the western Carolinas will keep the pressure gradient tight during Thursday, especially to the waters south of the ILM marine forecast area. During the latter parts of the forecast seas will be highest (5'+ across the southern 20-60 nm waters, and will likely be steep since the dominant waves will be counter to the Gulf Stream. Minimal chances for showers by the middle of next week, especially near the Gulf Stream.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Freeze Warning from 1 AM to 9 AM EST Sunday for NCZ087-096-099- 105-109. Frost Advisory from 1 AM to 9 AM EST Sunday for NCZ106>108-110. SC...Freeze Warning from 1 AM to 9 AM EST Sunday for SCZ017-023-024- 032-033-039-055-058-059. Frost Advisory from 1 AM to 9 AM EST Sunday for SCZ054-056. MARINE...None.