Rainy and Cold in the Bay Area
Permalink | Comment (0)Somewhat of an unusual weather pattern in the Bay Area recently. A cut-off low (that is, cut off from the jetstream) has been stubbornly lodged along the coast with enough over-water fetch to pump moisture in the form of rain and snow into central California. Here’s the Pacific surface analysis for today showing the location of the low.

More cold air will be heading down the west coast on Friday. Expect more precipitation which will be locally heavy in the typical wintertime orthographically-enhanced areas (e.g., the North Bay, San Lorenzo river valley, Santa Cruz mountains, etc.). The tropopause temperature map below shows this new (and bigger) blob of cold air currently off the coast of British Columbia.

And to keep your inner meteorological geek happy, here’s a snippet from today’s Area Forecast Discussion:
bq.. DIFFERENT RUNS OF SAME MODEL…SPECIFICALLY GFS…INDICATING SOME REFORMATION AND ULTIMATE RETROGRESSION OF THE CLOSED LOW CENTER TONIGHT ALONG W130. THIS WILL RESULT IN THE AFOREMENTIONED RISE IN THE FREEZING LEVEL AND CONTINUED MODERATION OF THE TEMPERATURES ALOFT INTO SATURDAY. MOISTURE CONVEYOR MOVES SLIGHTLY NORTHWARD HITTING MORE TOWARD THE CENTRAL PART OF THE FORECAST AREA…AROUND S.F.BAY LATE FRIDAY AND SATURDAY. THE CONTINUED MOIST AIRMASS ALONG WITH DYNAMICS AND OROGRAPHICS WILL ENHANCE PRECIPITATION ALONG THE SOUTHWEST SLOPES. OBSERVED PRECIPITATION AMOUNTS OVER THE LAST FEW DAYS RUNNING 3/4 TO 1.5″…AND FORECAST AMOUNTS UP TO 3-7″ MORE RAIN OVER THE NEXT 3 DAYS…HYDROLOGIC PROBLEMS ARE LIKELY FOR CENTRAL COAST STREAMS. FURTHER STATEMENTS WILL BE ISSUED LATE TODAY IN REGARD TO THE ANTICIPATED PROBLEMS.
HEAVY RAINS AND GUSTY SOUTHERLY WINDS TO CONTINUE INTO SATURDAY BEFORE THIS LOW MOVES TO THE SOUTH AND EAST. SHOWERY CONDITIONS WILL CONTINUE ACROSS THE DISTRICT THROUGH SUNDAY.
p.. Zoinger says… get an umbrella
