Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 190550 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1250 AM EST Sun Nov 19 2017 .SYNOPSIS... A strong cold front will pass through the area late tonight and Sunday morning. The front may be accompanied by some gusty late night showers. The front will usher in much colder and drier air with Monday seeing the lowest daytime highs with the possibility for a freeze or frost late Sunday night and Monday night. Temperatures will moderate Tuesday and Wednesday. Forecast uncertainty increases mid to late next week as another cold front moves into the area. The weather could turn unsettled and will hinge on the track of developing low pressure in the Gulf of Mexico. && .NEAR TERM /THROUGH TONIGHT/... As of 9 PM Saturday...A quiet evening before the cold front descends upon us. Warm advection in advance of the cold front keeping temperatures quite elevated as compared to yesterday at this time, with readings in the mid 60s most places. Latest from SPC has out counties west of I-95 in a thunderstorm risk area, but not in a severe category. At the pace of the approaching line of convection, still looks like an early morning arrival at the earliest. Forecast looks good to go, no changes anticipated. Previous discussion from this afternoon follows: A potent shortwave as seen on water vapor imagery across Kansas will rapidly move across the area tonight all the while shearing out. This will bring a moisture challenged cold front across the area with timing a couple of hours either side of 12 UTC. Models have trended drier with the front with at most a broken line of fast moving showers moving from west to east. Winds will crank up tonight ahead of the front at 15-25 MPH with higher gusts. With the fast moving flow, clouds and what few showers there are will clear out quickly Sunday. Lows tonight will not fall off much with the gradient increasing with middle to upper 50s common. For Sunday there is some cold air advection but certainly not overwhelming with highs in the lower to middle 60s. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 300 PM Saturday...With PW values a mere 0.2" for much of the period there will likely not be a cloud in sight. The exception may be some wisps of cirrus Monday night as some upper jetting strengthens off the coast and the Carolinas end up near the left entrance region. Mid level clouds may also be lurking close by to our SW in a tongue of enhanced warm advection. While moisture will be in short supply cold air will not. Forecast soundings show as little as 2000ft of vertical mixing through Monday afternoon, keeping high temperatures mired in the 50s even as moderate warm advection will be occurring at higher levels. Both nights will feature an inland light freeze while temperatures closer to the water remain in the upper 30s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 300 PM Saturday...A couple of short wave troughs in the southern stream will have some impact on area weather in much of the extended period though confidence is currently low in exactly what those impacts will be due to model divergence. The first upper trough will bring a chance of showers to the area Tuesday into Wednesday as a cold front moves through the area. After this fropa, the second upper trough could spawn low development along the front off shore and bring rain to the area Thursday into Friday. For now...the forecast reflects slight chance to chance pops Tuesday into Wednesday with slight chance pops for Wed night into Friday. Temperatures will be near seasonal normals of the mid 60s Tuesday and Wednesday before falling back into the mid to upper 50s for Thursday and Friday. Slightly warmer temperatures are expected Saturday with highs in the upper 50s to lower 60s. Mins will see a similar trend falling from the mid to upper 40s Tuesday night to the mid 30s to around 40 Thursday night before rebounding to the 40s by Saturday night. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/...
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As of 06Z...Weakening squall line apparent on regional mosaic is associated with a cold front crossing the Appalachians this morning. This front will move quickly eastward, crossing all the terminals overnight, and be offshore shortly after daybreak. As this occurs, a brief 2-4 hr window of showers with MVFR vsbys/cigs is likely, but should not be more than transient and have carried TEMPO MVFR at all terminals to account for this. A more steady impact to aviation will be gusty winds, from the SW ahead of the front up to 25 kts, and from the NW on Sunday with only a slow decrease in speeds. Wind gusts will likely persist to near 20 kts all day Sunday from the NW, before easing late in the valid period as high pressure ridges in from the west. Cloud cover will dissipate rapidly on Sunday such that SKC will become the rule by late morning and persist through Sunday night. Extended Outlook...VFR conditions are expected Sunday through Tuesday morning. Possible MVFR in showers Tuesday night through Wednesday. VFR Thursday.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 9 PM Saturday...Winds are increasing and seas building according to the latest obs. For now estimate that seas are 3 to 5 ft over a majority of the waters with winds of 15 to 20 kts gusting to around 25 kts. Still expect conditions to deteriorate further as the night goes on. No changes needed with the latest forecast update. Previous discussion follows: Quiet enough over the coastal waters currently with with winds in the lower teens and seas three feet or so. Winds and seas will rapidly increase this evening through the overnight hours well into a 25-30 knot range. This, as strong low level jetting precedes a cold front. There may be some gusts into Gale criteria but since the strongest winds will be in warm air advection, the need for a Gale warning isn`t a given. Winds turn offshore early Sunday, from the north, northwest at 15-20. Significant seas ramp up quickly from the current three feet to well over small craft criteria by midnight and continue through most of the day Sunday. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 300 PM Saturday...Sunday night brings a moderately strong yet relaxing gradient as chilly high pressure airmass builds in from the west. Flow will veer slightly from NW to N or even NE and advisory- worthy wind speeds should be outside of the 20nm zones. On Monday expect a more pronounced relaxation of winds and seas due to the high moving overhead. The high remains over the area Monday night while elongating to the east. Winds will remain minimal and turn onshore while seas smooth into the 1-2 ft range most areas. LONG TERM /TUESDAY THROUGH THURSDAY/... As of 300 PM Saturday...Return flow behind the departing high Tuesday will buckle as a coastal trough develops along the Southeast coast. Winds should turn easterly on Tuesday, then perhaps southeasterly for a time Tuesday night as the trough makes its closest approach to shore, but by Wednesday morning the feature should retreat back offshore as high pressure advances across the Ohio Valley and shifts our winds to a more north to northeast direction. Light winds and slight seas are expected until Wednesday night or Thursday when NE winds of 15 to 20 KT could build seas to 4 to 5 FT with 6 footers possible at 20 NM. && .ILM WATCHES/WARNINGS/ADVISORIES...
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SC...None. NC...None. MARINE...Small Craft Advisory until 6 PM EST this evening for AMZ250- 252-254-256.
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&& $$ SYNOPSIS...99 NEAR TERM...REK/JDW SHORT TERM...MBB LONG TERM...RAN AVIATION...JDW MARINE...ALL is the U.S. government's official web portal to all federal, state and local government web resources and services.