Key MESSAGE 1, A positively tilted upper-level trough will move across the Midwest THU, becoming neutral to slightly negatively tilted over NE CONUS THU night. At the surface, a slow moving cold front will move into ENC, pushing S of the FA by THU night. Timing differences still in place across avail HiRes guidance due to development of weak lows along the boundary upstream. Depending on the depth of these waves, FROPA could start as early as THU morning in the Nern FA, or as late as THU evening. These timing differences could have significant impacts on T/Td, Max temps, and available instability for storm development.
THU, moisture convergence from Sern stream system over SWern CONUS and the approaching system to the N will be aided by weak areas of SFC low pressure along the front upstream will lead to an increase in clouds and rain chances after midnight tonight into the early morning hours THU. Forcing is expected to be relatively weak locally with greater dynamics and stronger jetting N of the FA. However, there is still a low, but non- zero, chance for some storms to be strong to marginally severe with ample bulk shear building through the day, albeit mostly speed shear which would favor more multi-cellular storm-modes. Instability available for convection associated with FROPA will depend heavily on the coverage of showers and thunderstorms early and the exact timing of the front. Current QPF for 6Z THU-6Z FRI ranges from 0.25-1" with highest totals over NWern zones of the FA. In addition to showers and storms, Thursday will bring gusty SW winds with gusts to 20-25 mph inland and 25-35 mph along the coast. Storms with greatest vertical development may mix down some of the stronger winds aloft, making strong wind gusts the greatest threat for the area.
KEY MESSAGE 2, Surface high pressure will briefly build in on Friday leading to a mild, mostly dry day with MaxTs in the low 70s. The high shifts offshore FRI night ahead of a shortwave to move through the Carolinas Saturday. This will lead to warmer, cloudier conditions to start the weekend with moisture advection ramping up in the Serly flow developing on the W side of the high.
KEY MESSAGE 3, Rain chances increased again later SUN into MON ahead of another front and wave of low pressure that is currently forecast to cross the FA through the day MON. Right now it looks like another potential high shear/low CAPE setup, so will continue to monitor the potential for stronger storms.
06z Wednesday through Sunday Increasing low-level moisture along a confluent axis near, and to the south, of ENC will continue to support areas of low stratus (4k ft) streaming off the western Atlantic through early Wednesday morning. Some guidance even show a few SHRA developing within this area, but it's likely that any of that activity should stay east of the TAF sites.
During the day Wednesday, a steady stream of mid-level moisture from the west should lead to a gradual increase in mid-level cloudcover. This will then be followed by a renewed surge of increasing low- level moisture Wednesday evening. This should support gradually lowering CIGs during that time. Additionally, increasing large-scale lift should lead to a gradual increase in the risk of SHRA and TSRA, especially just beyond the current TAF cycle.
Light southerly winds overnight will give way to increasing winds during the day Wednesday in a typical summer-like pattern with gusty winds along and behind the developing seabreeze.
Outlook: A cold front will slide south through ENC on Thursday with a continued risk of SHRA and TSRA. Additionally, there will be a risk of IFR CIGs (40-60% chance). A northerly wind shift will occur along the front. Drier air moving in behind the front should support improving aviation conditions by Friday. Looking ahead, the next opportunity for sub VFR conditions looks to be over the weekend. There will be a risk of TSRA over the weekend as well.
Latest obs show SSW winds at 5-15kt inside, 10-20kt offshore with choppy seas 2-3 ft@5-6sec. Moderate to gusty SSW winds will continue as a slow moving cold front approaches and finally crosses THU. Light showers possible over Gulf Stream waters during peak heating today. Have added a SCA for coastal waters S of Ocracoke Inlet to the already existing central waters SCA for the strengthening winds reaching criteria this afternoon. Sw winds will increase to 15-25 kt with gusts to 25-30 kt tonight into Thu, building seas to 5-7ft coastal waters, 7-9ft offshore waters. Showers and storms likely ahead of the front THU.
Outlook: Winds will veer to the NW Thursday night behind the front with seas peaking at 5-8 ft. Winds will decrease to 15-20 kt with gusts to 20-25 kt by Friday morning with good boating conditions returning by the afternoon as high pressure builds in. The improvement will be short lived with showers and storms expected again SAT with troughing traveling over regional waters behind the high pressure sliding further offshore. Another brief lull expected early SUN before conditions deteriorate yet again ahead of a front to cross early next week.
Nc, none. Marine, small craft advisory from 5 pm this afternoon to 5 am EDT Friday for amz152-154. Small craft advisory from 8 pm this evening to 2 am EDT Friday for amz156-158.
