top border

Please note, not all links may be active. This site is a snapshot of an earlier time.

Lots of food for thought...

Josh Larson @ 12:00 PM

TOPIC ONE: 7-10 Outlook - Atmospheric Background
We have remained locked into a general pattern over the past month a mean ridge over the western US and a mean trough over the eastern US.  As such, there have been no significant, prolonged heat waves or periods of well above-average temperatures over the past month.  As Jason pointed out, we're running below average for 90-degree days this summer.  A relatively amplified flow pattern over Canada, as well as some hints of blocking, has all but shunted the development of significant ridging east of the Rockies recently, and the source region for air masses aloft has generally been from the west or northwest, instead of the south or southwest. 
TOPIC TWO: 7-10 Outlook - What this means for DC 
My thinking: (1) near-normal temperatures continue through Friday, with highs near 90. (2) A period of below-average temperatures will develop Saturday through at least the middle of next week, as a trough reloads over the East.  I expect high temperatures from 80-85 through the middle of next week. (3) Near-average to slightly below-average temperatures hold for the rest of the month. (4) Going out on a limb here, but after Friday, I think it is unlikely we will see temperatures above 90 for the rest of the month.
TOPIC THREE: Precipitation??
Though parts of the region have seen above-average precipitation this month, much of the storminess this month has been very hit-and-miss.  I wrote about this last week, referring to it as "The Washington Split."  I haven't seen a drop of rain here in Chevy Chase, MD in about 10 days now.  Unfortunately, I do not anticipate too much in the way of frequent, widespread, or significant rainfall over the next week.  There is about a 50/50 chance your location will see rain today (Thursday), and a slight chance on Friday.  Saturday largely looks dry, though Sunday through Tuesday a front may stall to our south, bringing at least the chance of widely scattered precipitation, though I don't expect it to be widespread at this point.  As we head into the start of August, we may have to look to the tropics to quench a rainfall thirst....
TOPIC FOUR: Ahhh...the tropics
I would say, subjectively, that the tropics have been somewhat on the quiet side over the past few weeks.  However, at present we note a tropical wave (storminess) over the Central Caribbean not too far from Hispanola.  The wave looks pretty unimpressive at the moment, and lacks surface circulation.  However, convection has been quite variable over the last 72 hours, at times looking decent, at other times looking puny.  However, this wave is entering a particularly favorable area of low-shear and good upper-level winds.  At this point, I won't sound any alarm bells, but we still need to keep our eyes on this one, as it may very well develop into a tropical depression, and perhaps tropical cyclone over the next 3-5 days....
Why the weather sometimes locks itself into a pattern over the summer
Tropical Weather Outlook from the Tropical Prediction Center

Comments are closed for this archived entry | Link | email post Email this post