VA WEEKEND WX MAY 7-8-9 and MAY 14-15-16
1105 EDT MAY 5
The main concern for the Middle Atlantic region and the commonwealth of Virginia this coming weekend will be the area of L ow pressure that develops on Thursday night and Friday over the Midwest. The Low itself is not going to track anywhere near the Middle Atlantic region. Instead the Low will track through the eastern Great Lakes and up across the Saint Lawrence river valley and then through Northern New England.
Its associated cold front will sweep through to the East coast some time during the day on Saturday. This is going to be one of the situations were forecasters are probably going to overemphasize the threat of showers and thunderstorms. This happens for number different reasons. For one there is a subset of meteorologists who loved to go bananas was severe weather events which can be a real problem with regard to ”overplaying “ or hyping these events in the northeast US. That is because a lot of times the same atmospheric conditions which will produce significant or major severe weather outbreaks in the Midwest or the Plains often has a lot less impact in the northeast US.
This bias towards over forecasting severe weather events especially early in the season can give off the wrong impression as to how much rain might fall with a cold front passage like this. In addition because a lot of meteorologists have this bias toward severe weather events they Mis read the synoptic setup.
This Low is pulling AWAY from VA NC on Saturday and it is weakening. This means WEST winds are likely Saturday…. which means DOWN SLOP which in turn means less humidity and Lowering Dew points
In any event most of Friday will be fabulous day with temperatures in the L to M 80s and low humidity. MOST of Saturday across most of the commonwealth will be rain free. The cold front will probably have already reached the Shenandoah and southwest Virginia — say interstate -81- by 10 am. It will be moving rapidly so the timing of the cold front passage will occur in the middle portion of the day… As opposed to late afternoon which is why we have maximum heating.
It would not surprise me at all IF the commonwealth did not see a single drop of rain from this cold front passage.
MAY 14-15-16
For the weekend of MAY 14-15-16… Right now it looks pretty dry. Besides this system moving through the Midwest on Friday there are s going to be two other significant Low pressure areas coming out of the mean trough located over the west coast in the next seven days. The first Low will be on MAY 11-12 followed by the second event MAY 14-15.
The systems will be forced to track through the upper Mississippi Valley and into the Great Lakes because in response to this trough the atmosphere is developing a strong ridge over the Gulf coast and southeastern states.
Temperatures will run warmer than normal for much of the Deep South but also it will turn dry.
It is possible that eventually this cold front over the Midwest on MAY 13-14 will push into the East coast by MAY 16-17… but I doubt it.
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3 MAY 1103 EDT
The clouds came into much faster than I had originally anticipated last week for this past weekend Last week I mentioned the possibility the temperatures could reach into the middle nineties on Sunday over much of central and Southern Virginia. However that was premised on the idea that the clouds would not move rapidly and until Sunday night or Monday. Clearly that did not happen.
On the other hand early last week I did correctly forecast the torrential rainfall for this past weekend over Tennessee and Kentucky.
MAY 7-8-9
The main change in the weather models on this Monday morning has to do with the development of a new system MAY 6 over the central Plains which tracks ENE into the eastern Great Lakes on May 7. That sort track means that the Middle Atlantic region will stay in southwesterly winds which will bring two fairly warm days until the Low’s associated cold front moves through late on MAY 8. This front should have some showers and thunderstorms with it on Saturday and Saturday night.
At the same time the next major piece of energy drops into the West coast over this coming weekend…MAY 7-8-9. This is going to be a major weather feature for the next 10-12 say because of this deep trough over California is going to eject several pieces of significant energy ENE in the 6-10 day.
MAY 14-15-16
The first one comes out through the central plains MAY 10-11. The Low will also Track ENE mainly be cause the models in response to this deep trough over the West coast start to develop a pretty strong ridge over the southeastern states. As a result the system as it moves through the Plains into the Midwest MAY 11-12 will track fairly far to the north.
This Low falls apart over the great lakes as the next strong piece of energy tries to come out of the West coast and Great Basin MAY 13-14. However the models continue to show a fairly strong ridge over the southeast so there’s a lot of uncertainty as to how fast this big West coast Low will come east. The European hangs this trough backed well west of the Mississippi River so that everyone East of the Mississippi is dry. The GFS is much faster with this Low and if it is correct this system will bring significant rains to portions of the Middle Atlantic states MAY 14-14-16




















