Area Forecast Discussion
Issued by NWS Newport/Morehead, NC
Issued by NWS Newport/Morehead, NC
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387 FXUS62 KMHX 100257 AFDMHX Area Forecast Discussion National Weather Service Newport/Morehead City NC 1057 PM EDT Thu May 9 2024 .SYNOPSIS... A cold front moves through the area on Friday, followed by high pressure over the weekend. Another front will come through around the middle of next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 1045 PM Thursday... On the regional surface analysis this evening, a stationary front is draped west to east across central VA, with a broad warm sector to the south across the Carolinas. However, moisture quality within the warm sector is questionable due to effects from the expansive MCS that moved out into the Atlantic earlier this evening. The combination of questionable moisture, a plume of drier air expanding east from the TN and OH Valleys, and limited forcing, continues to favor limited thunderstorm potential, and I have continued to trim back pops (no only to 5% or less). In light of this, we can give the all clear for severe weather potential tonight. PREVIOUS DISCUSSION...Latest obs show a diffuse seabreeze pinned close to the coast. The forecast for the remainder of the period has trended even drier, so PoPs have been decreased across the board. The greatest chance for showers or thunderstorms will be east of Highway 17, but coverage will be isolated. The environment is still capable of supporting strong to severe storms with gusty winds and small hail, but confidence in them developing is low. Tonight, SW winds will be 5-10 kt with lows in the mid/upper 60s across the FA. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... As of 3 PM Thu...A cold front makes its final approach tomorrow. The area should stay dry through the morning but PoPs will begin to increase in the early afternoon. The CAMs are showing fairly widespread showers and thunderstorms through the evening hours, but the best environment to support strong to severe storms will be south of Highway 70. MLCAPE around 500-1000 J/kg, deep layer shear around 45-50 kt, and mid-level lapse rates of 6.5-7 C/km could support strong wind gusts and hail. Highs will reach the low 80s across the coastal plain and upper 70s along the beaches. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As 3 PM Thu...Cold front pushes offshore Friday night with drier and cooler weather forecast for this weekend as high pressure ridging builds in from the south and west. More unsettled weather then approaches ENC on Tue/Wed. Friday Night...While instability will be marginal at best with guidance suggesting somewhere around 250-750 J/kg of MLCAPE across the region, shear will remain quite potent persisting at 40-50 kts as a low and cold front move through. This may end up promoting a few stronger to marginally severe storms into the evening with a few stronger gusts and some small hail possible, though given the limited instability across the region current thinking is we may see more general thunder. Decent low level forcing in place with a cold front developing with sfc low. Sat and Sun...Cold front will have pushed offshore by morning with blustery nrly winds in it`s wake in the morning. Upper troughing remains over the eastern CONUS this weekend while a cutoff upper low over the Four Corners region begins to push E`wards towards the Plains. Yet another shortwave will round the base of this troughing on Saturday before ridging finally begins to build in from the west on Sun. At the surface low pressure with attendant fronts will be diving SE`wards across the Ohio River Valley and into the Mid-Atlantic on Sat before moving offshore on Sun and pulling away from the region while high pressure ridge will gradually build in from the south and west. Capped precip to mostly around 10% with dry downsloping nwrly flow. Cloud cover should mainly be over the coastal locales, esp OBX, but may be some bkn diurnal strato cu all areas with the cold air aloft. Highs only getting into the 70s each day while lows dip down into the 50s each night. Mon through mid week next week...Upper ridging finally builds over the Eastern Seaboard and quickly pushes offshore by Tue as previously mentioned cutoff low opens into a trough and tracks E`wards towards the Mid-Atlantic Tue and Wed. Associated shortwave also quickly pushes E`wards bringing our next threat for unsettled weather to the area around Tue/Wed. As s/w makes its way E`wards surface cyclogenesis occurs across the Plains with low pressure and its associated fronts quickly approach the Carolinas from the south and west Tue. There remains considerable differences in the exact timing and location of this low next week but it is looking like this will bring our next threat for measurable precip Tue into Wed. Went below NBM guide due to these differences and capped pops at 50% for now. Temps remain about avg across the region next week. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... SHORT TERM /through 00z Saturday/... As of 600 PM Thursday... KEY MESSAGES - TSRA possible on Friday (40-60% chance) - Sub VFR risk associated with the TSRA risk FORECAST DETAILS An expansive area of TSRA well to our south has helped to lower the risk of TSRA across ENC, and I expect this trend to continue through the night. It appears the only real chance for a few SHRA or TSRA is in the vicinity of KFFA through about 02z/10pm tonight. Otherwise, through the evening, a plume of drier low- mid level air is forecast to spread east across ENC, leading to a reduced risk of low CIGs. With this TAF update, I`ve opted to remove all low CIGs for tonight. Additionally, it appears the drier low-level air will lead to a reduced risk of BR/FG, and I`ll continue keeping this out of the TAFs for now. Some shallow fog (MIFG) cannot be ruled out, but the risk of impactful FG appears low (<20% chance). On Friday, moisture will steadily increase ahead of a cold front approaching from the NW. The general theme with model guidance is for an increased chance of SHRA and TSRA. It should be noted that another large cluster of TSRA to the south may have an impact locally on how expansive the coverage of SHRA and TSRA is, which lowers confidence in what the impact will be for aviation interests. Despite the lowered confidence, there still appears to be enough model support for a VCTS mention Friday afternoon. LONG TERM /Friday night through Tuesday/... As of 320 AM Thu... Sub-VFR conditions will be possible on Fri in any shower or thunderstorm that impacts the region as a cold front tracks across ENC. As we get into the weekend and beyond expecting primarily VFR conditions into the end of the period. && .MARINE... SHORT TERM /through tonight/... As of 1045 PM Thursday... Winds have laid down quicker than forecast, apparently due to a weakening gradient across Eastern NC. The gradient may tighten again overnight, but it appears the risk of 25kt winds has decreased. Because of this, I have opted to cancel a portion of the SCA early. For the remainder of the SCA, I`ll keep that up due to elevated seas. PREVIOUS DISCUSSION...Latest obs show SW winds around 10-20 kt with gusts to 25 kt and seas 3-6 ft. Isolated showers and thunderstorms are possible later this afternoon/evening. The environment is capable of supporting strong to severe storms, but with the drying trend of the forecast through the today, the confidence in that happening is low. SCAs continue for the Pamlico Sound until 09Z and for the coastal waters until 12Z. LONG TERM /Friday through Monday/... As of 325 AM Thu...Cold front will push through the region on Fri with shower and thunderstorm activity expected. Locally enhanced winds and seas will be possible within any thunderstorm that impacts our waters. More benign weather then forecast this weekend into early next week. At the start of the period widespread 10-15 kt W-SW`rly winds with gusts up around 20 kts will persist across all our waters while 3-5 ft seas will be noted along the coastal waters. As we get into the afternoon and evening, cold front will have pushed offshore but a wave of low pressure will have developed along this front and have begun deepening. This will allow winds to shift from a W-SW direction to a N-NE direction Fri afternoon and evening from N-S with winds increasing to 15-25 kts with gusts up around 25-30 kts Fri night. In response to the increased winds, seas will build primarily north of Ocracoke to 4-6 ft once again promoting a brief period of SCA conditions across our waters. N`rly winds will quickly ease on Sat down to 5-10 kts with seas along our coastal waters returning to 3-5 ft and eventually 2-4 ft Sat aftn as the front and deepening low pull further away from our waters. More benign boating conditions are then forecast as winds generally remain at 5-15 kts and seas at 2-4 ft. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...Small Craft Advisory until 8 AM EDT Friday for AMZ152-154-156- 158. && $$ SYNOPSIS...MHX NEAR TERM...RM/OJC SHORT TERM...OJC LONG TERM...TL/RCF AVIATION...RM/RCF MARINE...RM/RCF/OJC