Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
406 PM EDT Tue Jul 17 2018
Valid 00Z Wed Jul 18 2018 - 00Z Fri Jul 20 2018
...There is a slight risk of severe thunderstorms over parts of the
Central Plains and the Northeast States...
...Heavy rain possible over portions of Arizona, Northern New Mexico and
Southern Colorado, as well as parts of the northern High Plains and the
...Hot temperatures expected across the southern Plains and southern
Mississippi Valley, as well as for the portions of the western states...
A large frontal system currently extends from New England southward across
the Central Appalachians and westward through the Tennessee Valley into
the Southern Plains. The eastern portion of this front will continue to
shift off shore into the Atlantic through Wednesday. Meanwhile, the
southern extent of the front will push southward into the Southeast
through the remainder of the week, while a low pressure system deepens
across the Southern Plains and begins to transition northeast as a warm
front for the remainder of the week. During this time, shower and
thunderstorm development is expected along the extent of the frontal
boundary. SPC has outlined a slight chance risk for severe thunderstorm
development along the New England coast for this afternoon and tonight.
Excessive rain and flash flooding is also ongoing in this area and will
likely continue into the overnight, before the front shifts off the coast
Meanwhile, upper level energy and a low pressure system over the Northern
Plains is also resulting in the development of strong showers and
thunderstorms. A slight chance for both excessive rain and severe
thunderstorm activity will remain in place across portions of the Central
and Northern Plains through tomorrow, transitioning eastward into the Mid
and Upper Mississippi Valley by Thursday. The best threat for severe
weather and excessive rainfall will be in the afternoon and evening hours
during peak daytime heating.
A strong push of warm air from the Gulf of Mexico is making its way into
the Southern Plains and Lower Mississippi Valley ahead of the above
mentioned frontal boundary. This is leading to excessive heat and
humidity, with heat advisories in place in portions of this area through
mid week. Out west, much of the Pacific Northwest, California, and the
western portion of the Intermountain West are experiencing very dry
conditions, which is aiding in boosting temperatures across this region.
Wind is also adding to the concerns as well. Heat advisories, warnings,
and Red Flag Warnings are all in effect across portions of these areas
through at least midweek.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php