This updated Forecast discussion is now being placed in the GENERAL weather section in addition to the Virginia weather section because the threat for MAJOR …possibly even a historic Heat Wave for the Middle Atlantic region is increasing. It also appears to be spreading into the lower portions of the Ohio Valley— aka the southern ECB – the Tennessee Valley and the Deep South.
Surprisingly the THREAT or the potential for seeing this sort of serious heat for several days in these areas is getting very little attention. I am afraid that is because there seems to be an over emphasis on the GFS and the GFS ensemble. This makes it less sense when one considers the unbelievabley BAD models performance by the operational GFS and the GFS ensemble with regard to hurricane Alex.
As we can see from this particular Image of the 6/30 run of 0z GFS for JULY 6-7-8 … The model that keeps the trough over the plains states moving straight through the Midwest. This ensures that there is no significant ridge in or dome that forms over the eastern Conus in any way shape or form. Really this is a CHICKEN vs EGG question. If we had a strong ridge over the eastern Conus the trough to slow down.. and temps would soar.
Here is the 0z 6/30 run of the operational European model from early this morning . At 500 MB we can clearly see the model continuing to form a very strong dome over the Middle Atlantic states and the Dark red shading shows 850 temperatures of +24c to +27c… which translates at the surface to temperatures well above 100°. Keep in Mind that here in Central Virginia we have already several days with temperatures above 100°.
These maps in ages shows the forecasted Max temperatures for our day afternoon of July 5 July 6 July 7 July 8 and July 9. The band of 100 plus degree temperatures is quite impressive and as you can see that there are two large areas of 105-110° over a portion of the commonwealth on July 6 and over VA into North central NC and over western TN and southeast MO on July 7.
Just in case you were wondering the record high temperature for the month of July in the city of Richmond is 105° which was set back on July 6, 1977.
1100 EDT JUNE 28
Now that I taken a week off because of my summer vacation … it is now s time to go back to work and figure out the weekend SUMMER forecasts for the commonwealth. Today will probably be the third day in the last five or temperatures reached over 100°here in Central Virginia. The cold front which is going to ride on the 30th will certainly be a welcome relief and it will ensure that the upcoming July 4 weekend will be spectacular. Friday, July 2 and Saturday, July 3 will feature and seasonal temperatures with low humidities an absolutely no friend of any sort of rain whatsoever.
Temperatures will begin to warm up of course by July 4 but this will be a great weekend so you should get out and enjoy it if you can.
However, that a weekend where facing a very interesting meteorological dilemma because the European and the gfs weather models are forecasting very different scenario as for the entire eastern Conus …. In the Middle Atlantic region …. For the period from July 5 to July 9.
Both weather models move the deep trough over the east coast out into the western Atlantic by July 4. This forces the large cool area of high pressure over the eastern Conus to move off the coast as well. In response for the trough moving off the east coast the strong ridge over the Rockies and the Plains rapidly expands the east.
The European models developing a heat dome over the eastern third of the Conus. The GFS does not.
Both models agree that another major trough will come out of Western Canada and the Pacific Northwest during the July 4 weekend which will track through the northern Rockies and into the Upper Plains by July 4. This front will undoubtedly bring widespread significant rain to the the Plains and the Upper Mississippi valley and some of the ramains /moisture of Alex will undoubtedly get pulled into the cold front so the rainfall amounts over the central Plains & the Mississippi Valley could be impressive.
The 0z Monday 6/28 run of the GFS moving right through the Midwest because the the model has no ridging or dome forming over the east coast . The Euro shows and a massive heat wave developing with temperatures rising above 100°over much of the Middle Atlantic states including the big cities of the northeast with the heat expanding into the Ohio Valley the Tennessee Valley into the Carolinas and the Deep South .
They will be interesting to follow this and see which of these very different solutions will be correct.