California's March Miracle Is Non Over

Some telephone phone it the "March Miracle"--the large amounts of atmospheric precipitation as well as snowfall that fallen over California the past times month.  The Sierra Nevada got hitting past times 2-5 feet this calendar week alone. And this is a miracle that is non over, alongside a strong atmospheric river poised to occur over the side past times side week.

Here are snowfall H2O equivalent maps (amount of H2O inward the snowpack) from the National Snow Analysis for Feb 17 as well as March 17.   A huge growth inward both depth as well as coverage.

The beginning of the wet bounty over California was a shift inward the large scale atmospheric circulation, alongside high describe per unit of measurement area moving farther offshore as well as persistent troughing (low pressure) developing over the West Coast.   To illustrate, hither is hateful upper marking (500 hPa, most 18,000 ft) heights for March 10-16th. The left shows the heights (analogous to pressure) as well as the correct shows the divergence (or anomaly) from normal.  Influenza A virus subtype H5N1 trough (low heights) is institute correct off the West Coast...that is culprit.

Well, this designing is non going away...and inward fact, it volition amplify inward a few days as well as our friends inward California postulate to instruct prepared.  Influenza A virus subtype H5N1 trough volition shape westward of California alongside strong southwesterly menses on its S side, which volition entrain large amounts of tropical wet (see map for eleven PM Tuesday below)

As a result, a strong atmospheric river volition develop, which volition choose tropical wet into primal as well as southern California (see plot of full wet inward the vertical for v PM Tuesday)

How much atmospheric precipitation volition those folks inward California enjoy?   Here is the forecast accumulated atmospheric precipitation over California for the side past times side vii days from the European Center Model:  upwards to 6-8 inches inward the Sierra Nevada as well as coastal mountains.

And enough around southern CA, such every bit the mountains that environment LA.

 Snowfall?  Up to 3- four feet inward the Sierra Nevada (see below)

With all the recent snow, the Sierra Nevada snowpack is most 60% of normal.  It volition instruct much closer to normal subsequently the side past times side few weeks.  And the reservoirs, already around 100% of normal, volition instruct topped off for the upcoming dry out summer.

The precisely negative of all this atmospheric precipitation is that it volition encourage the growth of grasses, which tin heighten the potential for burn danger side past times side autumn subsequently it has dried out.  

Here inward the Northwest, our province of affairs volition last far less exciting than for California, alongside much of the large activeness going S of us.  The 7-day totals demo the heaviest atmospheric precipitation over western Oregon but precisely lite atmospheric precipitation over the Puget Sound expanse as well as the San Juans.