Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KILM 271901 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 301 PM EDT WED JUL 27 2016 .SYNOPSIS... High pressure will expand across the Carolinas, maintaining uncomfortable levels of heat and humidity this week. Isolated to scattered showers and thunderstorms are possible each afternoon and evening. The chances increase heading into early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 3 PM Wednesday... What little cumulus clouds have developed have succumbed to dry mid level air. Have thus trimmed our in situ POPs out of the forecast. Storms developing to our north will tend to move eastward and stay out of the area based upon steering flow. Should a cold pool develop they may drift a bit south-enough to where some slight chance POPS seem warranted along the northern fringe of the CWA. This idea is supported by very few models other than the RAP, and storms to our north last evening tried to do so with no luck. Otherwise tonight will be mainly clear, warm and muggy. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...Heat wave not only continues but appears to peak in intensity on Thursday. Most areas well into the upper 90s and a few spots inland likely to hit 100. No relief from the sea breeze save for south facing Brunswick County, as it will remain pinned to the coast elsewhere. Solid Heat Advisory criteria with dewpoint forecast now critical to who sees Heat Warning criteria and for how long. Steeper hydrolapse rates are forecast and thus some lower values may mix down to the surface. The exception may be along the coastal counties where some slightly higher dewpoints remain intact at the surface. A few spots could hit a heat index of 110 but not for long enough or over enough real estate to justify an Excessive Heat Watch at this time. An upper impulse passes by on Friday leading to slight height falls. This will slightly temper the heat and yield about 20 percent rain chances over roughly the northern 2/3 of the CWA. Heat indices will still be solidly in advisory criteria. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 3 PM Wednesday...Weak 5h troughing over the KY/TN valleys this weekend will migrate off the coast for the middle of next week. The resulting increase in moisture and mid level cooling will lead to an increase in diurnal shower and thunderstorm coverage through the period. The main surface features and convective triggers will continue to be the Piedmont trough and the sea breeze with outflow from the initial storms spawning others. Precipitable water values will be at or above 2 inches through the period, which could lead to periods of excessive rainfall. Late in the period the steering pattern becomes rather anemic with storm motion dropping under 10 kt, so flooding could become an issue. Best precip chances look to be Mon and Tue as the trough axis moves into the region. Precip chances decrease slightly for Wed as the mid level trough axis moves offshore and weak subsidence moves overhead. High temperatures a few degrees above climo at the start of the period will trend toward climo by the middle of next week. Low temperatures will run above to well above climo. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... As of 18Z...VFR IS expected through the 24 hour TAF valid period. It is very unlikely that any convection will develop today due to very dry air aloft. However, few to scattered CU should develop this afternoon and then fade with the sunset. EXTENDED OUTLOOK...Isolated to scattered afternoon convection through Sunday may create brief periods of MVFR/IFR. Otherwise expect VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 3 PM Wednesday...High pressure at the surface and aloft will keep a southwesterly flow through the period. A few knots of wind may be added to the forecast as a weak low level jet develops. Seas will remain in the 2 to 3 ft range. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 3 PM Wednesday...Not much will change on the surface weather map through the period with high pressure remaining well offshore. A low level jet will develop Thursday night and this could add a few knots of wind to raise the forecast to 15 to 20kt. Some 4 ft seas are progged to develop but they may remain just outside of the 20nm zone border. These winds and seas may remain on Friday as though the LLJ weakens a piedmont trough may drift a bit closer to the coast increasing the gradient. LONG TERM /SATURDAY THROUGH MONDAY/... As of 3 PM Wednesday...Bermuda High will maintain southwest flow over the waters with afternoon speed enhancement via the Piedmont trough. Speeds will range from 10 kt in the morning to a solid 15 kt with higher gusts in the afternoon. Seas will run 2 to 4 ft. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Heat Advisory until 7 PM EDT this evening for SCZ017-023-024- 032-033-039-053>056. NC...Heat Advisory until 7 PM EDT this evening for NCZ087-096-099- 105>110. MARINE...None. && $$ NEAR TERM...MBB SHORT TERM...MBB LONG TERM...III AVIATION...REK is the U.S. government's official web portal to all federal, state and local government web resources and services.