Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Mon Jul 03 202

[Techman]

Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Mon Jul 03 202

3Valid 12Z Mon Jul 03 2023 - 12Z Wed Jul 05 202

3...Locally heavy rain and embedded thunderstorms over the lower Great Lakes/Ohio Valley today will taper off by July 4th but they will linger over New England...

...Excessive heat over California and Desert Southwest will become less intense as heat intensifies over the Pacific Northwest...

...Brief heat wave over the northern Plains will be ended by a period of showers and possibly strong thunderstorms followed by rapid cool down...

A low pressure wave currently moving across the lower Great Lakes is forecast to move into New England and gradually weaken through the next couple of days. Very warm and moist air ahead of the system will continue to promote scattered showers and thunderstorms throughout much of the eastern U.S. today. Areas of locally heavy rain are possible within a broad shower/storm activity especially early today with greater chances for flash flooding closer to a stationary boundary extending from the lower Great Lakes to southern New England. Lesser chances of heavy rain and thunderstorms can be expected to extend as far south as the interior Southeast and into the Deep South. Meanwhile, a cold front slowly pushing into the Ohio Valley will bring drier and cooler air toward the East Coast as we head into the 4th of July holiday. The chance of showers and thunderstorms will generally decrease through the eastern U.S. on Independence Day as the low pressure system is forecast to weaken further. However, areas from New England and down along the Eastern Seaboard and further down across the Deep South will likely see some fireworks from nature later on Independence Day where the air will remain very warm and moist.

Meanwhile, the heat wave across the South will be less oppressive today, before confining southward even more on Independence Day. Nevertheless, heat indices could approach 105-110 degrees with high temperatures into the mid-90s, which can be dangerous if spending an extended amount of time outdoors. Additionally, heat will be the main story throughout the Desert Southwest and West Coast today and Tuesday. Highs well into the triple digits are forecast throughout the Central Valley region of California and Desert Southwest. A few daily high temperature records could be challenged today, before the record-breaking heat potential shifts up the West Coast into northern California and western Oregon. Here, highs are forecast to reach into the 90s and low 100s on Tuesday.

Elsewhere, thunderstorm chances remain across the central and southern High Plains today, with potential for localized heavy rain and damaging wind gusts. A potent cold front entering the northern Plains will spark another area of scattered thunderstorms extending from south-central Montana to the Upper Midwest. Temperatures ahead of this front will be very warm, with highs into the mid-90s across parts of Minnesota and South Dakota. The thunderstorms and gusty winds will signal the arrival of much cooler temperatures as the potent front pushes across the northern High Plains toward the northern Rockies, where highs as much as 20 to 30 degrees below average are forecast on Tuesday. By Wednesday morning, these thunderstorms are forecast to reach into the upper Midwest as well as farther southwest into the central High Plains.

Kong/Snell

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