Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
422 AM EDT Thu Oct 14 2021

Valid 12Z Thu Oct 14 2021 - 12Z Sat Oct 16 2021

...Tropical moisture from former hurricane Pamela continues to bring heavy
rain and flash flooding today from south-central Texas to southeastern
Oklahoma...

...Threat of severe weather increases later on Friday for the Ohio Valley
ahead of a developing low pressure system...

...The cold in the West and the warmth in the East will shift eastward
heading toward the weekend...

The weather pattern across the mainland U.S. is forecast to undergo a
noticeable change during the next couple of days.  This pattern change
will shift the prevailing cold pattern in the West and the persistent
warmth in the East eastward as we head toward the weekend.  First of all,
the intense low pressure system that has brought heavy snow and high winds
across the northern/central Rockies into the High Plains is getting ready
to depart into southern Canada.  The remaining snow and rain over the
northern Plains should come to an end by this afternoon although the winds
will remain rather strong and gusty.  This intense storm plays a key
initial role in eroding the persistent warm ridge that has been anchoring
in the eastern U.S.  Meanwhile, another low pressure system is brewing
over the southern High Plains ahead of an upper trough sliding across the
western U.S.  This system is forecast to intensify while tracking toward
the lower Great Lakes along a frontal boundary during the next couple of
days.  Showers and thunderstorms are expected to form ahead of the system
with the best chance for the thunderstorms to become severe later on
Friday across the Ohio Valley.  By Saturday morning, the showers/storms
will likely reach western New England as the intensifying storm moves into
Ontario, Canada.  In the wake of this system, the cold air in the West
will be ushered into and through the Plains states.  The coverage of
warmth in the East will then shrink as southerly winds spread the warmth
further north toward New England.

In the shorter term though, ample tropical moisture associated with former
hurricane Pamela surging into the southern Plains will continue to create
an environment ripe for thunderstorms capable of producing intense
downpours.  Several inches of rain are possible between south-central
Texas and southeast Oklahoma where a Moderate Risk of excessive rainfall
is expected for this morning.  The heavy rain threat may also extend into
parts of western Arkansas and the Middle Mississippi Valley as well.  By
later today, the heavy rain threat is forecast to diminish quite a bit as
the main energy is forecast to shift into the southern High Plains where a
new low pressure system is forming.  Meanwhile, moisture associated with
the upper trough moving across the western U.S. is expected to spread
high-elevation snows across the Intermountain region and into the central
Rockies for today and into tonight.  By Friday, a strengthening high
pressure system will bring drier and colder than normal conditions across
the vast majority of the West.  The exception will be near the Pacific
Northwest coast where a stream of Pacific moisture will bring persistent
rain into the region.

Kong


Graphics are available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php