The mid and upper-level
trough and associated cold
front will
approach the area Monday night into Tuesday, with significant
uncertainty as to whether a
shortwave will round the base of the
trough or if it will remain positively tilted. This has
ramifications for whether there are any
height falls ahead of the
front and whether or not a surface low deepens to our northwest
which will determine the degree of low-level mass response. What
models currently agree on, however, is that as is typical for this
time of year
shear will be high but
instability will be weak. An
easterly component to surface winds due to high pressure over New
England will be attempting to pinch off the warm sector with time,
with a tendency for the 850mb
jet axis to try to out-run the warm
sector. Will continue to indicate a conditional marginal severe risk
across our far western and southern counties, which will be
conditional on whether parameters can line up just ahead of the
QLCS.
Risks will include gusty to isolated damaging winds, with
isolated weak tornadoes possible if the QLCS can remain or become
surface-based before low-level shear weakens through the day on
Tuesday. Some 25 to 30 mph
gradient wind gusts will be possible as
well. Probabilities of at least an inch of beneficial
rainfall
are also high across much of the area.
