Tropics & The Long Range Weather Outlook Summer Continues
This is good time to take a look at the tropics & the long range weather pattern. It seems that the current pattern we are in with fronts coming through on a semi regular basis will continue. We continue to see a rather active jet stream pattern across Canada which continues to send weather systems along in the flow. The southern extent of that jet stream has been moving back and forth from just along the Canadian border to the Middle Atlantic States.
This has kept stretches of heat relatively short as we saw with last weekend. That was one of those stretches where the jet stream pulled up well north only to drop back south with severe weather and then a shot of dry nice air. This is what we are seeing today and this stretch takes into the weekend. Humidity will be coming back over the weekend and early next week as we set the table for the next cold front. Temperatures will be climbing to the upper 80s to near 90 beginning Saturday and upper 80s to lower 90s will be dominating the scene Sunday through at least Tuesday. Another trough is going to be dropping into the East for the middle of next week.
Not every thing is exactly the same but there is a sense that it rhymes somewhat with what we just went through. This would time out for later Wednesday into Thursday with a chance for thunderstorms again. Whether it would a severe weather risk or not remains to be seen and is a short range issue. Nothing in the overall pattern suggests this scheme we are in is going to change over the long haul.
As far as the tropics are concerned the area of interest is in the Gulf of Mexico. This is the southern end of the frontal boundary that found its way into the Gulf and you can see a large area of thunderstorms elongated from South Texas to Florida. There is nothing tropical about the frontal boundary. Under certain conditions as the differences between the air mass to the north and the tropical air to the south begin to lessen and disappear, the frontal boundary falls apart but the convection and thunderstorms remain. A low could form on the dying boundary and gradually acquire tropical characteristics. We saw this happen a couple of weeks ago with Barry which formed on the southern end of a frontal boundary that dropped into the Northeast Gulf of Mexico.
The Nam model today shows a weak low developing in the Western Gulf of Mexico over the next 2 days but it doesn’t do much with it but it does illustrate how such a low comes about in a set up like this. It is a long shot at this point because the air to the north of the frontal boundary is very dry and that is an inhibiting factor. Notice on the surface map you have the temperature and the dew point for reporting stations along the Gulf Coast. We have dew points in the 50s and lower 60s right down to the coast. The tropical air is to the south of the orange line.
Also upper air winds are not that favorable for development over the next few days. Watch the satellite loop for clues as to whether something is going to try and form here. Elsewhere in the tropics activity is subdued across the Atlantic and subtropical Atlantic which is not at all unusual for late July. I would expect tropical activity to pick up in the coming weeks as we head into the seasonal peak in September.
MANY THANKS TO TROPICAL TIDBITS FOR THE USE OF MAPS
Please note that with regards to any tropical storms or hurricanes, should a storm be threatening, please consult your local National Weather Service office or your local government officials about what action you should be taking to protect life and property.