Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Thu May 23 2024 Valid 12Z Thu May 23 2024 - 12Z Sat May 25 2024 ...Heavy rain and severe weather threats across the Arklatex region today will expand northward across the northern and central Plains tonight... ...Heavy rain and severe weather threats will shift east into the Midwest and remain across the Arklatex region on Friday... ...Heavy snow expected today across the higher elevations of the northern Rockies... As a low pressure system continues to move further away from the Great Lakes into southeastern Canada, showers and thunderstorms ahead of the associated cold front will push farther eastward across New England and the Mid-Atlantic states today. Meanwhile, the trailing portion of the front will become nearly stationary across the Mid-South where the focus of heavy rain and severe thunderstorms will be the greatest today. These thunderstorms may reform across the Arklatex region as the frontal boundary meanders in the vicinity, along with the arrival of some additional lifting mechanisms from an upper-level jet stream from the west-southwest. The jet stream winds will tend to carry the showers and storms downstream across the Mid-South toward the Appalachians and the Mid-Atlantic states, keeping the weather unsettled for these areas through the next couple of days with modest rainfall amounts although locally heavy rain can be expected in some of the embedded thunderstorms. Meanwhile, a rather deep and compact upper-level low from Alaska a couple of days ago is now sweeping across the northwestern U.S. This system will continue to usher a cold air mass through the western U.S. with a round of heavy wet snow across the higher-elevations of Idaho, western Montana, and into northwestern/northern Wyoming today. The energy from this system will help develop another low pressure system across the northern and central High Plains today. The low pressure system is forecast to further intensify on Friday as the upper low exits into northern Plains and begins to lift toward the northeast. Another round of showers and possibly severe thunderstorms will develop and expand across many locations up and down the Great Plains later today, and will begin to lift east and northeastward into the Midwest, and along the Mississippi Valley on Friday. A swath of cold rain is forecast across North Dakota, southeastern Montana, and into northwestern Minnesota as the low pressure center tracks just to the south. Temperatures could be cold enough for some wet snow to mix in with the rain later tonight near the Canadian border. Increasingly strong and gusty winds will also add to the chill as the low pressure system intensifies and wraps the precipitation around the center of circulation. By Saturday morning, the showers and storms should progress into the Great Lakes and down across the Midwest ahead of and near the cold/occluded fronts. Meanwhile, scattered showers and storms will linger across the Mid-South into the Southeast where the old front lingers. Across southern Texas an early-season heat wave is forecast to gradually intensify through the next few days into the Memorial Day weekend. Record or near-record warm overnight temperatures will provide little to no relief to those without adequate or reliable cooling. By this weekend, record daily high temperatures and heat index readings over 115 degrees in South Texas will also be possible. Check local media and government websites for cooling center locations and hours, especially if you encounter or are dealing with a loss of power. If you use a portable generator, do so safely to avoid carbon monoxide poisoning. Never use a generator inside a house, garage, or other enclosed space! Finally, a critical fire danger is forecast for the southern Rockies into the southern High Plains per the Storm Prediction Center. Kong/Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php