Area Forecast Discussion
Issued by NWS Newport/Morehead, NC
Issued by NWS Newport/Morehead, NC
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142 FXUS62 KMHX 301752 AFDMHX Area Forecast Discussion National Weather Service Newport/Morehead City NC 152 PM EDT Tue Apr 30 2024 .SYNOPSIS... A weak cold front will move through the area on Wednesday. High pressure then builds in for a couple of days before yet another cold front impacts the area over the weekend. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... As of 1010 AM Tuesday...No changes needed to the previous forecast. Mid-level ridge axis is beginning to shift offshore as shortwave trough, currently digging into the Gulf States, continues to migrate eastward into tonight. Despite continued low-level moisture advection, the combination of residual subsidence and warm temps aloft are expected to keep the risk of showers at a minimum again today as the seabreeze moves inland. Yesterday the chance of showers was close to zero. Today it will be about 5-10%. Once again, temperatures this afternoon will top out in the mid 80s inland(~10 degrees above normal), and the 70s along the coast (close to normal). && .SHORT TERM /7 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... As of 200 AM Tuesday... SFC low pressure is forecast to pass south of Southern New England tonight, with an associated weak frontal boundary moving slowly east from the Appalachians to the Carolinas and Virginia. A modest LLJ is forecast to develop ahead of the advancing front, with steady low- mid level moistening expected through the night. Mid-level lapse rates will be weakening with time, but a deepening layer of moisture appears supportive of a zone of modest instability, especially on the nose of the strongest elevated moisture transport. Within this zone, SREF probs give a 50-70% chance of MUCAPE > 500j/kg developing ahead of the front and an upper level shortwave approaching from the west. Large-scale forcing for ascent is forecast to be on the weak side, but a weak coastal trough moving inland plus modest low-mid level convergence appears supportive of scattered showers and thunderstorms developing from coastal SC northeast through SE NC after midnight. Weak effective shear (~20kt) is expected to limit any severe weather potential tonight. Where thunderstorms manage to develop, rainfall amounts as high as 0.25-0.50" will be possible. Otherwise, amounts are forecast to be less than 0.10". With increasing clouds, and steady boundary layer moistening, temperatures tonight are expected to be very mild for late April, only dropping into the mid 60s. For perspective, normal lows this time of year are in the mid to upper 50s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As of 330 AM Tuesday... KEY MESSAGES - Inland highs in the low to mid 80s for the rest of the week - Best rain chances Wednesday and then an unsettled weekend and start to the new week FORECAST DETAILS A shortwave trough will move east across the area on Wednesday and support shower and thunderstorm chances (30-60%). As for severe potential, the threat appears low but non-zero with the high CAPE/low shear environment being painted by the CAMs. Highs will reach the low 80s with dew points in the low 60s, which will generate plenty of instability to support thunderstorms. The CAMs are showing large MUCAPE of 1500-2000 j/kg but weak effective shear. However, it should be noted that the CAMs are showing a higher amount of shear than they were 24 hours ago. This is especially true along counties south of HWY 70 near the coast, so this will be a trend to keep an eye on. We return to warm, dry weather on Thursday and Friday with a ridge building over the southeast US. Highs will be in the mid 80s across the coastal plain and low 70s at the beaches. Unsettled weather returns this weekend with multiple chances for showers and thunderstorms. Surface high pressure will be gradually washed out as a surface low forms due to a shortwave trough moving across the southeast. At the same time, a cold front associated with a deep low over south-central Canada will move into our area and stall. PoPs increase west to east on Saturday with shower and thunderstorm activity possible through Monday (15-30% chance). && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SHORT TERM /through 18z Wednesday/... As of 150 PM Tue...The probability of sub-VFR conditions in the next 24 hours is low - between 10-20%. VFR conditions prevail across terminals today as high pressure remains off the southeastern coast and broad diurnal cu field continues to build inland. Dry conditions expected for the rest of today in gusty southwesterly winds, which will turn southerly late tonight as sea breeze advances northward. Precipitation forecast has changed a bit since last night. Guidance has become more bearish on precip coverage overnight as weak trough of low pressure approaches from the west. OAJ and to a lesser extent EWN would be most at risk of seeing overnight shower activity, as well as an isolated thunderstorm, primarily after 06z. Isolated to scattered coastal activity will be ongoing after sunrise on Wednesday, but main focus will turn to the end of the TAF period as sea breeze converges with trough and brings scattered to numerous showers and thunderstorms across the area. Bulk of activity is expected around and after 18z. LONG TERM /Wednesday through Saturday/... As of 330 AM Tuesday...Pred VFR expected through the period but a few instances of unsettled weather are expected. An approaching disturbance will bring chances for showers and thunderstorms on Wednesday (30-60%). By Saturday, a cold front will be moving into the area and bring another chance for showers and thunderstorms (15-30%). Lowered CIGs and VIS are expected during these times. && .MARINE... SHORT TERM /through tonight/... As of 200 AM Tuesday... Background northeasterly long-period swell continues through tonight, and will combine with a modest southerly wind swell, producing seas of 3-5 ft. Like yesterday, breezy southwesterly winds of 10-20kt will be common through tonight, with a few gusts to near 25kt where the thermal gradient in maximized. Because of the marginal nature of the winds, we`ll continue to run headline-free. Late tonight, an upper level disturbance and a developing weak coastal trough is expected to support an increasing risk of showers and thunderstorms, especially for the southern waters/rivers/sounds. LONG TERM /Wednesday through Saturday/... As of 330 AM Tuesday... KEY MESSAGES - Sub-SCA conditions with multiple chances for showers and thunderstorms FORECAST DETAILS Although marine conditions are forecast to remain below SCA criteria, opportunities for showers and thunderstorms are possible Wednesday and this weekend. Winds will be variable through the period due to several systems moving through but will remain around 5-10 kt with 2-4 ft seas. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...MHX NEAR TERM...RM/MS SHORT TERM...RM LONG TERM...OJC AVIATION...MS/OJC MARINE...RM/OJC