Webberweather53
Meteorologist
Storm5 link said:
Yeah, I'm personally getting tired of seeing the EPS produce a semi-permanent trough over the Rockies and SE US ridge which fails to materialize. The GEFS has been doing this as well to an extent although it's been considerably better wrt recognizing when the SER breaks down and the trough over the west comes east.
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that was big shift in the EPS. As you have been mentioning , the 10-12 day eps seems to have been on repeat with the trough over the rockies and holding onto the the SER. The question for me becomes , how stable will the pattern be IF it pays out as advertised. The EPO looks like it's going to at least hang on for a few weeks. The -NAO seems kinda transient which we have become numb to at this point .
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I personally wonder what's up with the EPS because this isn't the first time this year it's held a trough too long (w/ too much amplitude) in the Rockies & western US, granted I sorta thought it was legitimate given the ENSO/QBO background)... Yea the -EPO will be a mainstay for at least a few weeks, and as far as I'm concerned there are a few ways this could evolve going into the middle portions of the month. If the North Atlantic blocking is transient, then we'll have a stretch of seasonably cool/variable wx with perhaps a decent threat for wintry wx somewhere down the line, and the Northeastern pacific & Alaskan block, (as is usually the case) will retrograde westward towards the Bering Sea & far eastern Siberia and lead to an appreciable -WPO, and the SE US will progressively intensify. (the observed retrogression of the Northestern Pacific block occurs because the anomalous rossby waves in the North pacific tends to have a very large latitudinal width, and therefore the difference in Coriolis forcing across the wave allows for its own self-perpetuating, westward advection that's a function of the differential in f (coriolis parameter) to overwhelm the mean westerly flow. Therefore it retrogrades westward despite the fact that the mean flow is westerly (this same physical concept also can apply to other rossby waves that retrograde westward, I just used the North Pacific as an example because this behavior occurs so often and has been observed so frequently of late)). Oth, if this north Atlantic block is stronger than modeled and is able to bridge over the top with the Alaskan block, then most of the US and Canada will get stupid cold as a massive PV lobe gets trapped over North America and we'll probably have some fun this month. Yea there's some uncertainty, but it's getting progressively harder for us to at least not get temporarily sideswiped by this PV lobe. Pardon for the technicalities in explaining the canonical (typical) retrogression of the North pacific block, there's no easy way to explain that lol...
