Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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
629 FXUS62 KRAH 040149 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 949 PM EDT Mon Jun 3 2024 .SYNOPSIS... A series of mid level disturbances will move east across the area through mid week, as a weak surface trough and unseasonably moist air mass holds over the region. A cold front will approach from the west Thursday and move across the area Thursday night and Friday, bringing drier and less humid conditions for the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 945 PM Monday... No meaningful chances where made to the overnight forecast with the evening update as the inherited forecast remains on track. Regional radar shows a weakening trend with convection over central NC. A weak mid-level ridge axis will pivot across the Mid-Atlantic tonight with only 10-20m height rises but will usher in drier mid- level air from the Ohio Valley and northern Mid-Atlantic. These features should act to limit overnight scattered overnight showers and result in most locations remaining dry. Isolated light showers can not be ruled out however as a continued highly moist, unstable, and weakly capped regime remains in place overnight. Hi-Res guidance understandably struggles in these weakly forced regimes, but best chances (5-15%) would be where low-level instability of 100-150 J/kg will exist from upstate SC through the northeast Piedmont and northern Coastal Plain of NC through the overnight hours. Lows overnight will settle into the mid 60s by early Tues morning. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... As of 230 PM Monday... Tuesday should be a relatively average June day with a Bermuda high in place and southerly return flow beneath weak ridging aloft. A weak backdoor cold front is forecast to settle down the Mid-Atlantic coast but models have trended further north with its final push and it doesnt quite reach Halifax and Edgecombe Counties, perhaps stopping over southeast VA per NAM 925mb fields. Aloft, there is a weak circulation over TN today but it should drift more northeastward tonight and doesnt appear to have much impact on convective development tomorrow. CAMs tend to slightly favor the northeast CWA, again perhaps in closer proximity to the weak convergence associated with the weak backdoor boundary. PW will increase to around 1.6, which is around the daily 90th percentile, and thus will support a little better coverage or storms, which will be slow moving given very weak tropospheric flow under the ridge. Will trend 30-50 POPs toward the northeast CWA during the afternoon, with otherwise partly to mostly cloudy skies once possible morning stratus in the Piedmont burns off. Highs will be in the mid to upper 60s, falling only into the mid and upper 60s overnight with a continued slight chance of a shower. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As of 250 PM Monday... Shower/storm chances will peak mid week within warm and humid conditions. We will then trend to dry weather and lower humidity by Fri with the pattern shift to anomalously low heights over the Great Lakes region and Ontario/Quebec, lasting through the weekend, albeit with gradual air mass modification back toward normal by Sun/Mon. Wed-Thu: Still appears that pops should be highest areawide Wed and in the Coastal Plain on Thu. Northern stream troughing in the Upper Midwest early Wed will continue to deepen and dig strongly to the SE through the Great Lakes region through Thu, leading to gradually strengthening WNW steering flow at our latitude and, especially, to our W and NW, as a synoptic cold front slowly approaches from the WNW. PW is expected to climb early Wed, nearing 2", near or exceeding daily records, and we`ll have strengthening SW low level jetting drawing greater moisture in from the Gulf. Models depict one particular shortwave (perhaps an MCV from Mid Miss Valley convection) swinging through the central and S Appalachians Wed night into Thu morning, and with the in situ water content and low level mass convergence amid improving mid level flow, it won`t take much to kick off clusters of showers and storms. Will have pops peaking at likely to categorical Wed into Wed night, then good chance W to likely E Thu as 850 mb troughing pushes through the area preceded by the low level jet shifting to the coastal Carolinas. A few storms may be strong esp in the E Thu into Thu evening where moderate to high MUCAPE is possible in tandem with the strengthening mid level flow to 30-40 kts. Temps should be near to a category above normal, with warm lows and clouds muting daytime heating a bit. Fri-Mon: The overall longwave pattern will shift to anomalously low heights aloft across a large swath of the Great Lakes, adjacent Canada and the Northeast as a deep northern stream low settles over or just N of the Great Lakes. Deterministic models and ensemble modeling systems are all in pretty good agreement on the overall pattern, although differences persist regarding the amplitude, wavelength, and orientation of the longwave trough axis, and these differences show up well in the various model clusters. Generally, though, with the cold front pushing to our SE, and a cooler air mass moving in with lower dewpoints, confidence is high that we`ll have generally dry weather starting Fri and going through the weekend, although by Sun/Mon, minor perturbations within the fast NW steering flow may knock down mid level heights briefly, resulting in bouts of buoyancy along with passing DPVA, supporting a few diurnal showers or storms, and will carry below-climo isolated afternoon pops both days. Expect temps slightly below normal Sat, rebounding to near normal Sun/Mon. -GIH && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 725 PM Monday... Generally VFR conditions are expected tonight. However, isolated showers/thunderstorms will be around the KRDU area through around 02z/04 associated with old outflow boundaries. In addition, some stratus and fog will be possible late tonight, especially 09z-13z around KRWI and KRDU. A return to VFR conditions are expected between 13z and 18z, with isolated to scattered thunderstorms during the afternoon (brief sub-VFR conditions). Outlook: Intermittent Sub-VFR conditions possible Wednesday into Thursday as a front moves through the area. Drier air is expected to move into the region Friday through the weekend with VFR conditions expected. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Swiggett SHORT TERM...BLS LONG TERM...Hartfield AVIATION...Badgett