NUTRIAD’S United States 30 Day Outlook (September 2018)
Author: Thomas Novak of Novak Weather Consultants
United States Overview:
In general, the Jet Stream steering winds will surge onto the northwest coast of the U.S., slice eastward into the Rocky Mountains then continue northeast into the Upper Midwest of the U.S. This jet stream pattern will likely develop a large ridge over much of the eastern U.S. In turn, warmer than normal conditions are expected anywhere east of the Mississippi River Valley (Basically the eastern ½ of the country). Meanwhile, Cooler than average conditions are expected along the northwest coast of the U.S. extending east into the northern Rocky Mountain region.
As the late summer ridge builds over the eastern U.S., DRY conditions will develop under the upper level high pressure system that anchors over the southeastern U.S., and more specifically, the Carolinas. In contrast, a strong jet stream with a Pacific tropical connection will bring plenty of rain to much of the Upper Midwest and Great Lakes regions. Of note, we will be keeping a close eye on the Gulf of Mexico states as the potential exists for a tropical system to develop over the next 30 days. This would bring heavy rains to portions of the Southern Plains and Deep South, especially along the coastlines.
The warm weather pattern will continue, especially over areas near and east of the Mississippi Valley. More importantly, an active jet stream with tropical moisture will be situated overhead much of the month. This will provide the region with plenty of opportunities for heavy rain. In fact, some areas are already experiencing flooding and the expected above average rainfall will only exacerbate an already dangerous flooding scenario in some locations. It has been feast or famine in this region as sharp moisture gradients exist due to spotty summer rains.
A strong high pressure ridge with sinking air is expected to anchor near or just south of this region during September. This weather pattern is in sharp contrast to the last several months as a mainly dry and unseasonably warm environment takes hold. Temperatures will often soar 10 to 20+ degrees above average. This will provide the region an opportunity to dry out from the copious summer rains that have fallen, especially over the northern Mid-Atlantic.
The northern sections of this region will experience a dry and warm month as a strong ridge of high pressure anchors nearby. However, all eyes will be on the Gulf and Atlantic Coasts as conditions become favorable for tropical development. If this occurs, heavy rains can be expected, especially along the coasts. Meanwhile, temperatures soar to much above levels as we continue to dry out under sinking air.
Special Note: We just can’t seem to shake the intense drought conditions over large sections of the region. Although some much needed rains occurred in pockets during the month of August, it wasn’t enough to alleviate the widespread drought conditions that continue plague this part of the country. Unfortunately, except for tropical rain potential along the Gulf Coast, it appears that much of this region will continue to be starved for moisture.
Concerns continue in this region. The big story all summer as been the prolonged and serious DROUGHT conditions, especially over portions of Kansas, Missouri and Texas. The good news is that the strong high pressure ridge responsible for these drought conditions is expected to anchor east of the region during September. In turn, moisture will have a better opportunity to surge north from the Gulf of Mexico. However, warm southerly winds will dominate which will push temperatures above average for much of the period.
piblished on Nutriad website 21/09/18.