Key MESSAGE 1, Hot and humid conditions will continue today. Heat Adv in place for most of the area with heat index values 105-110 deg through early evening. We will see a dip in heat MON with greater cloud coverage through the day and more rain helping bump down MaxTs into the upper 80s and low 90s, but SWern zones may still require heat headlines. Tue and WED MaxTs climb back into the low 90s for most and afternoon Tds approaching 80deg will bring heat headlines back into play.
KEY MESSAGE 2, There are several factors expected to support an increasingly active pattern into next week.
Upper level troughing will continue to strengthen over the Eastern U.S. With ridging shifting away from the area. Persistent S-SWerly flow E of the trough, potentially with a subtropical connection, should act to enhance low-mid level moisture across the area. Meanwhile, heating of a moistening boundary layer should lead to sufficient instability and reduced inhibition in support of periods of convection. Lee- side troughing and, eventually, a frontal boundary that will reach the FA by MON should provide areas of enhanced low- level forcing today with gradually improving mid and upper level flow becoming more conducive to organized storm modes as trough aloft sharpens.
Today, the SFC front currently draped through central VA will approach the FA. General trend appears to be a slight slow down of the front entering the Nern FA, sometime this evening or the first half of tonight. Spc's outlook for today features a Slight Risk (lvl 2/5) for the bulk of the area. Scattered showers and storms blossoming across the area quickly this afternoon. Latest mesoanalysis shows SBCAPEs on the order of 4-5 kJ/kg across the area with bulk shear 20-30 kt. Moisture pooling and low level convergence will be maximized this afternoon into tonight as the cold front approaches. Pwats peak on the order of 2 and 3/4in in conjunction with increasing afternoon and evening instability. Main concerns will be the potential for damaging wind gusts, heavy rain and freq lightning late afternoon into tonight. Wpc continues its Slight Risk for excessive rainfall today, highlighting the potential for localized flash flooding.
The National Hurricane Center has begun issuing advisories for TD Two. Though no explicitly tropical impacts are expected from this system locally, this low could act to enhance rainfall along the SE coast by further increasing Gulf moisture transport from its Eern half through early next week while the stalled lingers across the region.
Tropics aside, deterministic and machine learning guidance continue to show a good signal for some strong to marginally severe thunderstorm potential during this period of active weather. This afternoon and eve remains the strongest signal for severe potential through TUE. Given increased forcing from the approaching front and the potential tap of subtropical moisture, heavy rain and some hydro impacts may eventually be realized.
MON, the stalled boundary located somewhere between the Neuse River and the NC/VA border, inland troughing persisting, and plenty of moisture influx from the S and SW will keep cloudy and active forecast in place. Fortunately, the mid and upper level trough over NECONUS will be pushing offshore, ending the little mid and upper level dynamic support system for organized convection. Iso strong storms with damaging wind gusts will be possible, along with the threat for heavy rain which could lead to localized flooding. Mon night, the boundary lifts back N, "warm- sectoring" the FA once again for TUE and WED.
A stronger front is forecast to approach and cross the area WED into THU, posing the next threat for severe weather later in the forecast period. Upper level pattern for this FROPA appears more supportive of stronger storms with a sharper trough aloft digging further S than the weekend trough, with the base of this trough actually crossing directly overhead.
KEY MESSAGE 3, WED/THU stronger front is forecast to make it through the entirety of the land area of ENC, but still stall offshore. This will lead to mostly N-NEerly flow late week into the weekend, cutting down on the heat (mid to upper 80s/upper 60s splits into the weekend). Severe threat appears minimal behind the midweek front, but the multi day period of showers in the forecast could lead to hydro issues.
00z Monday through Friday Predominantly VFR conditions in place across area terminals but still a healthy amount of convection all around the eastern half of NC. Near term threats are highest for OAJ and PGV, with attention turning to a renewed band of showers and storms developing from roughly KIWA to KRDU along the main front as it pushes east. This will advance across the coastal plain between 00-02z bringing a low risk of stronger gusts up to 35-40 kt and torrential rainfall briefly lowering visibilities below a mile. Coverage of showers and storms likely to become much more isolated after 04-05z.
Guidance still suggesting post-frontal low stratus development overnight starting around 08-09z, although placement of the boundary at this time is uncertain. Most likely terminals to see MVFR are ISO and PGV, with low (20%) odds of seeing IFR. Some locally dense fog is also possible given likely light winds, but higher odds for this are north of the NC/VA border where skies will be clearer.
VFR expected to return by late tomorrow morning. Scattered to numerous showers and storms expected again, with potential for iso stronger storms producing gusty winds.
Outlook (Monday night through Friday): Another approaching front, this one looking stronger, renews stronger shower and thunderstorm chances WED into THU.
Latest surface and buoy obs indicate SW winds 10-20 kt gusting 20-30 kt, strongest over the Gulf Stream, with seas 2-4 ft north of Hatteras and 4-7 ft south. Scas continue for Pamlico Sound and nearshore coastal waters through tonight. Approaching cold front will stall across the northern waters late tonight into Monday, keeping light easterly flow north of the boundary and moderate to breezy S-SW winds south. Seas will peak this afternoon and evening, grad subsiding to 3-5 ft Monday morning.
Scattered to numerous showers and thunderstorms expected across the waters through Monday. Sct strong to severe storms likely with damaging wind gusts, heavy rain and freq lightning.
Outlook (Monday night through Friday): For the outer waters, elevated winds and seas may last for much of the week. A stronger front is forecast to approach and cross regional waters mid to late week, bringing another round of strengthening SW winds and tstorm chances, mainly later Tue and Wed. Sca conditions likely to develop later Tue cont into Wed night.
Nc, beach hazards statement until 8 pm EDT this evening for ncz195- 196-199-204-205. Marine, small craft advisory until 2 am EDT Monday for amz135. Small craft advisory until 6 am EDT Monday for amz152-154-156- 158.
