Lexington Weather

Lexington, Massachusetts, USA
63°F
4/26/2025 8:17pm
Lexington Conditions: Overcast
Temperature: 63.0°F / 17.2°C
Dew Point: 61.5°F
Relative Humidity: 95%
Wind: SW Calm, 10-min avg: 1 mph, gust: 8 mph
Barometer: 29.62 in Steady
Visibility: 10 miles
Rain Today: 0.64 in
National Short Range Forecast Discussion

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
330 PM EDT Sat Apr 26 2025

Valid 00Z Sun Apr 27 2025 - 00Z Tue Apr 29 2025

...Wet snow along the Sierra Nevada, parts of the Great Basin this
weekend, and then the northern Rockies Sunday night/early Monday...

...Heavy rainfall and snowmelt will lead to a risk of flooding for
portions of the northern High Plains of Montana Sunday...

...Outbreak of severe weather, including strong tornadoes, expected for
portions of the Midwest/Plains Monday...

...Much below average temperatures continue across California, the Great
Basin, and the Southwest with much above average temperatures spreading
from the Plains into the Midwest/Southeast...

An active Spring weather pattern will continue across large portions of
the U.S. through the weekend. A deep upper-level low has brought a period
of unsettled weather to the West including both rain and periods of snow
given the much cooler temperatures in place. Showers and some
thunderstorms over California/Oregon and into the western Great Basin
today will spread northeastward across the Great Basin and into the
northern Rockies by Sunday. Winter Weather Advisories are in place for
higher elevations of the Sierra Nevada and even for some of the ranges
into southern California for accumulations generally between 3-6", locally
as much as 8-12". Winter Storm Watches are also in place for portions of
the northern Rockies in Montana for accumulations as much as 6-12".
Accumulating snowfall should be limited to higher elevations, but the
colder temperatures may result in some snow mixing in for lower elevations
of the Great Basin/northern Rockies overnight Saturday and into Sunday
morning.

A moist airmass along a quasi-stationary boundary already in place across
portions of the central/southern Plains ahead of the approaching
upper-low/trough has been responsible for multiple days of locally heavy
rainfall/flash flooding and severe weather. An ongoing complex of storms
across Oklahoma this afternoon as well as the possibility of some
additional storms later along the periphery of the complex could lead to a
few additional scattered instances of flash flooding, with a Slight Risk
of Excessive Rainfall (level 2/4) in place. Storms ahead of the complex in
southeastern Oklahoma as well as another round of isolated convection
along a dryline further west over the southern High Plains will also pose
a severe weather threat, with a Slight Risk (level 2/5) from the Storm
Prediction Center for the threat of very large hail, damaging winds, and a
few tornadoes.

The boundary will finally lift northward as a warm front overnight
Saturday and into the day Sunday as the approaching upper-low/trough
begins to overspread the Plains. The surge of strong, moist southerly flow
northward and upper-level support will lead to a broad area of showers and
thunderstorms Sunday over the northern Plains. A combination of moisture
and upslope flow along the Rockies will lead to widespread showers and
thunderstorms anchored along portions of the northern High Plains of
Montana. Locally heavy rainfall as well as Spring snowmelt across terrain
sensitive areas including burn scars has prompted a Slight Risk (level
2/4) of Excessive Rainfall for the threat of some scattered flash
flooding. Additional storms are expected further east, with sufficient
CAPE and very strong dynamics with the approaching trough leading to the
potential of some severe weather. A Slight Risk is in place along portions
of the northern/central High Plains primarily for the threat of large
hail. An eventual complex of storms moving through the Dakotas late Sunday
and into the early morning hours Monday may also lead to some isolated
flash flooding.

The upper trough and an accompanying surface low pressure/frontal system
will shift eastward from the Plains into the Midwest on Monday. The
continued impressive dynamics given the strength of the trough, with
strong winds at both upper- and lower- levels, as well as the surge of a
moist, unstable airmass northward will lead to widespread, intense
thunderstorms Monday afternoon and evening. A Moderate Risk (level 3/5) is
in effect for the Upper Mississippi Valley where an outbreak of severe
weather, including strong tornadoes, is expected. A broader Enhanced Risk
extends southwestward into the Middle Missouri Valley with a Slight Risk
into the southern Plains where more potentially significant but a bit more
isolated instances of very large hail, damaging winds, and tornadoes will
also be possible. 

Elsewhere, scattered showers and thunderstorms will continue this
afternoon ahead of a cold front across the Northeast/Mid-Atlantic, with
most storms coming to an end later this evening as the front clears the
coast. Storms will linger longer into Sunday over portions of the interior
Northeast/northern New England, with some snow potentially mixing in for
higher mountain elevations. Very dry conditions, warm temperatures, and
strong, gusty winds have prompted a Critical Risk of Fire Weather (level
2/3) from the Storm Prediction Center for northwestern New Mexico today.
Even stronger winds expected Sunday will lead to an Extremely Critical
Risk of fire weather (level 3/3) over portions of central and southern New
Mexico as well as far west Texas. The deep upper-level trough over the
western U.S. as well as a corresponding upper-level ridge intensifying
over the central/eastern U.S. will lead to an increasing dichotomy in well
above average and below average temperatures this weekend and into next
week. Well above average temperatures over the Plains Sunday will expand
eastward across the Midwest and Southeast Monday, with the
Northeast/Mid-Atlantic also seeing above average highs. California, the
Great Basin, and the Southwest will see another day of well below average
highs on Sunday before conditions moderate closer to average on Monday.
Areas of the Pacific Northwest and northern Great Basin will remain at or
above average.

Putnam


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