Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
358 PM EDT Tue Aug 14 2018

Valid 00Z Wed Aug 15 2018 - 00Z Fri Aug 17 2018

...Heavy rain possible across New England and the northern Mid Atlantic...

...Heavy rain and thunderstorms possible across portions of the plains
through tonight, shifting eastward into the Mississippi Valley for
Wednesday...

...Fire weather concerns continue across the West with the threat of dry
thunderstorms sparking new wildfires...

A quasi-stationary front extending from parts of the Northeast southward
across coastal parts of the Mid-Atlantic into parts of the Southeast will
slowly dissipate by Wednesday morning, with most showers and thunderstorms
expected to taper off. However, the driving surface low pressure center
will remain over the Northeast during this time, coupling with a strong
upper level low. This will advect large amounts of moisture inland across
the Northeast. The Weather Prediction Center has continued a slight risk
of excessive rainfall and flash flooding across much of the Northeast and
into the northern Mid Atlantic through tonight. Flash Flood Watches and
Warnings are also currently in effect across this area.

Meanwhile, another low pressure system will continue to gain strength
across the Central Plains as it slowly shifts eastward towards the Middle
Mississippi Valley by Wednesday evening. A strong surge of warm, moist air
from the Gulf of Mexico will clash with colder air moving in from the
north, resulting in a frontal boundary and creating the epicenter for
showers and thunderstorms over the next several days. The Weather
Prediction Center has outlined a large portion of the Southern and Central
Plains, eastward into the Mid and Lower Mississippi Valley as being in a
slight risk for excessive rainfall through tonight. This risk area will
shift eastward, extending from the Low/Middle Mississippi Valley and into
the western Ohio Valley during the day Wednesday, and then into the Great
Lakes region by Thursday. Flash Flood Watches are currently in effect for
eastern Oklahoma and northwest Arkansas.

Yet another frontal boundary is currently draped across the Central and
Northern Plains this afternoon. This will couple with an upper level low
pressure system to bring forcing, instability and moisture to portions of
this region. The Storm Prediction Center has outlined Northeast Wyoming
and far southeast Montana as being in a slight risk for severe weather
today. This slight risk region will shift eastward for Wednesday, settling
across western Nebraska. A marginal risk of severe weather is also in
effect in the same vicinity.

Elsewhere, fire weather concerns continue across the west. While monsoonal
moisture moves into the Southwest, the threat of dry thunderstorms and new
fire development will extend farther northward across much of the West. A
large portion of Central California as well as much of the Pacific
Northwest, Northern Great Basin, and Northern Rockies are under an Air
Quality Alert due to smoke from ongoing wildfires. Red Flag Warnings are
also in effect across portions of Northern California and southern Oregon,
as well as much of northern Nevada and far Southeast Idaho as the threat
of dry thunderstorms looms through mid week.

Wix


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