Old Res Weather
Lexington, Massachusetts, USA
35°F
2/16/2025 7:17pm
- Clear
-
35.1°F / 1.7°C
-
32.4°F
- 90%
- Calm, 10-min avg: Calm, gust: None
-
- 10 miles
- 0.01 in
- $VPuv None
National Short Range Forecast Discussion
Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 229 AM EDT Mon Jul 27 2026 Valid 12Z Mon Jul 27 2026 - 12Z Wed Jul 29 2026 ...Dangerous heat wave continues over parts of central and southern U.S. into next week... ...Risk for severe thunderstorms and flash flooding will spread from the Upper Midwest into the Great Lakes and Northeast over the next few days... ...Active monsoonal moisture fuels thunderstorms over the Four Corners Region, Rockies, and High Plains... A broad upper ridge centered across central and southern U.S. will continue to produce widespread dangerous heat from the Plains into portions of the Mississippi Valley and Southeast. Afternoon highs will reach the upper 90s to low 100s with isolated areas within the Desert Southwest seeing up to 115-120. Additionally, record breaking overnight lows will stay within the 70s. The high temperatures combined with high humidity will lead to widespread heat indices exceeding 105-115 degrees. Much of the central/southern Plains, Mississippi Valley, and Southeast will see Major to Extreme HeatRisk levels on Monday. On Tuesday, the Major to Extreme HeatRisk levels becomes confined to the Southern Rockies, Southern Plains, and the Southeast. Areas northward will see some relief from the heat as a embedded shortwave brings thunderstorms chances across the central Plains and a cold front drops into the Midwest. Across eastern U.S., a longwave trough deepens over the Great Lakes and Northeast and several embedded shortwave disturbances rotate through the base of the trough, bringing chances for unsettled weather across the area. At the surface, a frontal boundary extending from the Upper Midwest into the Ohio Valley will sag southeastward, while a secondary cold front pushes into the Northeast by late today into Tuesday. The rich Gulf and Atlantic moisture pooling along the boundary, the strengthening low, and the unstable airmass will support organized convection that will produce heavy rainfall and severe thunderstorms along the boundaries. There is a Enhanced Risk (level 3/5) of severe thunderstorms for parts of the Upper Midwest/Upper Great Lakes into the Ohio Valley for today. These clustered storms may also produce large hail and damaging winds. Additionally, there is a Marginal Risk (level 1/4) of excessive rainfall and flash flooding for portions of the Great Lakes, Ohio Valley, and Northeast. On Tuesday, another shortwave trough will rotate into the Great Lakes, while cyclogenesis develops across the interior Northeast. This will maintain the warm moist environment, leading to a reinforcement of widespread showers and thunderstorms along the boundary. With the chance for training to develop, slow storm motion, and instability, a Slight Risk (level 2/4) of excessive rainfall and flash flooding for portions of the Mid-Atlantic into New England, while a broad Marginal Risk (level 1/4) encompasses much of the Northeast. Furthermore, there is a Slight Risk (level 2/5) of severe thunderstorms for the Mid-Atlantic into North Carolina and parts of the Appalachians that may also produce isolated hail and damaging winds. Across the Southwest into central U.S., an active monsoon pattern persist, as deep tropical moisture continues to bring chances of showers and thunderstorms across the Four Corners and portions of the Rockies/central Plains. Localized flash flooding remains a concern for the next few days, especially over burns scars, slot canyons, urban areas, and steep terrain. Additionally, there is a Slight Risk (level 2/5) of severe thunderstorms across portions of the north/central Rockies/Plains for today. These storms may also produce isolated severe wind gust across Southeast Arizona. Furthermore, repeated heavy thunderstorms across the Gulf coast/east Florida may lead to flash flooding concerns on Monday as rainfall totals may reach up to 6". Oudit Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php