2230 EDT 31 MAY
Yes Virginia we ARE going to see what could be SIGNIFICANT and widepsread severe weather outbreak affecting most of North Carolina …Virginia …West Virginia …Maryland …central and eastern Pennsylvania …and Delaware on Friday June 1. There are several reasons why this particular severe weather threat COULD be more a significant severe weather.
The Thursday evening weather map shows a area of LOW pressure developing over KENTUCKY.. There are numerous Moderate to heavy storms over IND OH KY with Moderate rain over southern MI. The LOW pressure area will track NE from KY to Cleveland then into the eastern Great Lakes. The upper level support or the Jet stream that is supporting this Low …is going to develop a certain angle as it reaches the East Coast. In the weather business this is called a NEGATIVE TILT ; that is to say the trough alignment be running northwest to southeast ( from Michigan to Virginia). This alignment in the upper level trough will enable thunderstorms to develop more rapidly than they might typically do with a Ordinary cold front . In addition this system will be pulling up a lot of warm humid air from the Deep south and from the Gulf stream off the Southeast coast. Initially skies should be clear to Partly cloudy for most of Friday and that could allow temperatures to get close to 90° or 92 especially over central and eastern Virginia …Maryland and North Carolina.
With each passing model run the data becomes stronger with regard to the severity of the thunderstorms as a cold front moves into far western North Carolina …West Virginia …and far western portions of Virginia on Friday morning.
The KEY aspect to this POSSIBLE widespread sever threat will be the developement of 2nd LOW on the Cold where the WARM front Intersect or met. This feature is a called a TRIPLE POINT Iin the weather Busioness and the 0z NAM 1JUNE model has the TRIPLE point showing up nicely. If the TRIPLE POINT develops as the NAM/ WRF is showing and tracks WEST of Richmond area thid would palce the worst storms over the Piedmont into the DCA Metro area and northwest VA.
In addition one of the aspects of severe weather here on the East Coast which often gets overlooked is the timing. In the Midwest and Plains the timing issue is often not that big of a deal… but on the East coast it is In this particular case the approach or timing of the cold front will be ideally situated to get maximum amount of heating as the thunderstorms approach and the cold front crosses these states. Most of the thunderstorm should be at or just west of I–95 in North Carolina ..Virginia ..and Maryland by 7:00 or 8:00 PM Friday.
SPC - storm prediction center—has been talking about this threat for 24 hours already. In the Thursday morning discussion they mentioned that they might raise the threat to MODERATE RISK for severe / torandic storms for most of North Carolina
…Virginia …and Maryland and this upgrade may occur this evening or Friday morning before the event actually begins.
Based upon the data I am looking late Thursday …it looks like the biggest threat areas will be from Charlottesville up towards Washington, DC including locations such as Strasburg Harrisonburg front Royal Warrenton Culpeper Leesburg and then into western and Central Maryland including all of Northern VA/
Washington, DC /Baltimore metro areas. A second area may develop from Richmond east into the Northern neck and Middle peninsula areas and perhaps into Hampton roads.
I suspect a large portion of Virginia and Maryland will be placed under a TORNADO Watch during the day tomorrow. The potential for rains up to 2 inches is pretty high especially over central and eastern portions of North Carolina …Virginia … and Maryland and the HAIL potential also quite high.
This whole system should be off the coast and done with during the predawn hours on Saturday AND this coming weekend looks spectacular… but the rains and storms will continue over NJ NYC CT and Much of New England through Saturday.
For next week JUNE 3-9…. temperatures will run below normal over the entire eastern half of the CONUS. This Low which is going to hit us tomorrow will continue to travel up the New England then stall off the southeast coast of Canada. It will be blocked from moving any further to the east the cause of a blocking feature in the Jet stream over northern and northeastern Canada.
This will force the jet stream to plunge from Minnesota down to Kentucky into North Carolina all next week. A boundary or front will set up next week from Georgia to Louisiana to Kansas and there will be numerous showers and thunderstorms over the Deep South and the Delta because of this front. But for Virginia …North Carolina …West Virginia Maryland … and Delaware …conditions will be pretty good with generally fair skies and normal or below normal temperatures for the entire week.
Beyond JUNE 2-9 the pattern and data clearly indicates that Mid and late JUNE is going to turn hotter. Once the blocking feature over northern Canada leaves …. the cooler air mass over the eastern U.S. will also leave. Heat building in over the SW conus and the Lower / central Plains will spread into the Midwest by JUNE 10 and into the Middle Atlantic by JUNE 12-13 and this hot pattern could last to JUNE 25-30. Rainfall may also become quite as scarce as well .