Good morning and Happy Sunday!
This week, the Western half of the country will continue to heat us as the Monsoon action in the Southwest refuses to slow down. For the eastern half of the country, the oppressive summer heat that tortured the region through much of June and July has finally come to an end as cooler temperatures continue to stick around this week.
Current Synoptic Picture
From west to east, there current exists some slight troughing in the Northwest, followed by a large upper-level high centered over the Texas and Oklahoma panhandles, and an upper-level low in another region of troughiness in the Northeast.
Once again, we will take a look at the weather in more localized regions in the country, starting from west and moving eastward.
Western United States
Much of the West Coast is, at the moment, experiencing some upper-level riding – which in general will help to keep temperatures warmer than average. The exception to this is the weak, disipating upper-level low over the Pacific Northwest, which will continue to exit the region through the end of the weekend. This will leave the entirety of the West Coast underneath a strengthening upper-level ridge, leading to widespread warmer-than-normal conditions.
One notable exception to the expected above-average temperatures will be made across portions of the Desert Southwest. This can be explained by the active Monsoon pattern, that will increase clouds and precipitation across the area, thus keeping temperatures cooler in the process. This relation can be seen by looking at a map of the precipitation anomalies through the next 7 days, where the Southwest is likely to receive above-average rainfall this coming week.
Southern, Central United States
Across the Central and Southern United States, however, the story is a little bit different. Thanks in part to a developing upper-level trough over the eastern half of the US, this part of the country (that has seen its fair share of extreme heat this summer) will likely experience normal to slightly below normal temperatures this week.
Where this cooldown is the most apparent is along the Ohio River Valley, where the mean temperatures could be as much as 10F below average.
With exception to parts of Texas, the only positive temperature anomalies can be found in Florida, where the temperature will likely be slightly above average this week.
This can be explained by an expected drier-than-normal week for parts of Florida, where afternoon showers and thunderstorms tend to limit the high temperatures. The American GFS model is showing a slightly drier week ahead, with rainfall departures approaching an inch for much of the Sunshine State.
Elsewhere on this map, you may notice the much higher-than-normal precipitation expected for other regions in the Southeast. This is due to the increased risk of showers and thunderstorms induced by shortwave troughs flowing around the larger upper-level trough.
Northeastern United States
Lastly, we arrive in the Northeast, which will follow a similar pattern of cooler-than-average temperatures this week, much like the Central and Southern parts of the country. Once again, this is because of the developing upper-level low that will be dominating the eastern half of the country this week. However, cooler weather and drier air associated with the upper-level low will help things stay drier across the Great Lakes and the Mid-Atlantic, the GFS model has been continuously hinting at a developing coastal storm bringing much needed rain to New England.
As of the 00z GFS late yesterday evening, the GFS was bringing a healthy 1 to 4 inches of rain to the region in the Tuesday evening through Thursday morning timeframe, resulting in some above-normal precipitation anomalies for the region.
Looking Further Ahead
Next, let’s take a look at the National Weather Service’s Climate Prediction Center is expected for the next 8-14 days…
For the last full week of August, the Climate Prediction Center has their highest probabilities of above-average temperatures for the the Northwestern and Northeastern Untied States, with the highest probabilities for below-average temperatures for the Desert Southwest – likely as a result of enhanced Monsoon activity in the region.
For precipitation, the chances of above- or below-average rain are weaker than that of the temperature probabilities, however the Climate Prediction Center determines that the Northern Great Plains will likely experience below-average rain, while much of the rest of the country is either expected to receive near normal, or slightly above-average rainfall.
