Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Wed Jun 05 2024
Valid 12Z Wed Jun 05 2024 – 12Z Fri Jun 07 2024

…Excessive Heat Warnings in effect across parts of California’s Central
Valley region as well as the Desert Southwest; Extreme Heat Risk continues
across south Texas…

…Thunderstorms and heavy to Excessive Rainfall possible from Southern
Plains to Northeast through Thursday…

A very pronounced ridge will build across the Western U.S. over the next
few days while upper-level lows influence the pattern across the lower 48
from their respective stations off the Baja and Nova Scotia Coasts. The
upper ridge will support a heat wave which will expand across the region.
High temperatures in the 90s and 100s will be 20-30 degrees above average
for this time of year, while low temperatures in the upper 60s and 70s
will offer little respite at night. Widespread high and low temperature
records may be tied or broken through Friday. There are Excessive Heat
Warnings in effect for California’s Central Valley as well as portions of
the Desert Southwest including southeastern California, southern Nevada
and western/southern Arizona. Mild night time temperatures will continue
to plague southern Texas through the end of the week. These extremely hot
conditions will affect anyone without effective cooling and/or adequate
hydration.

A pair of low pressure systems tracking across the eastern half of the
country will trigger scattered to isolated showers and thunderstorms
across much of the region today before shifting into just the East Coast
on Thursday. Deep layer moisture paired with instability will support
locally heavy rainfall over parts of the Ohio Valley, Central Appalachians
and Mid-Atlantic where a Slight Risk (at least 15%) of Excessive Rainfall
leading to Flash Flooding is in effect for today. The threat for Excessive
Rainfall shifts into parts of the interior Northeast and New England on
Thursday, where another Slight Risk of Excessive Rainfall is in effect. A
pattern change will ensue across the Eastern U.S. on Thursday, in which a
digging trough will usher in cooler air temperatures and continue through
the weekend.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Tue Jun 04 2024
Valid 12Z Tue Jun 04 2024 – 12Z Thu Jun 06 2024

…There is a Moderate Risk of Excessive Rainfall leading to Flash
Flooding over parts of southeastern Oklahoma and the ArkLaTex today…

…Severe Thunderstorms possible across parts of the Mississippi Valley
today…

…Growing Excessive Heat potential over portions of California’s central
valley region as well as the Desert Southwest; southern Texas heat risk
persists…

An amplified upper trough will swing through the Great Plains and
Mississippi Valley, bringing with it a pair of cold fronts and
thunderstorm activity over the next couple of days. Potent mid-level
energy on the southern periphery of the trough anchored over
southern-central Canada will move slowly across the Deep South today and
promote a pair of MCSs to propagate across the ArkLaTex region this
morning and then again tonight. The repeating thunderstorms (potentially
severe) over the same area prompted the issuance of a Moderate Risk (at
least 40%) of Excessive Rainfall leading to Flash Flooding over portions
of southeastern Oklahoma through the ArkLaTex for the 24 hour period
ending Wednesday morning. Frontally driven diurnal convection will also
occur across the Upper/Middle Mississippi Valley this afternoon and
evening. The Storm Prediction Center issued Slight Risks (level 2/5) of
Severe Thunderstorms over parts of the Upper/Middle Mississippi Valley and
another one across the ArkLaTex into western Mississippi. Large hail and
severe wind gusts will be the main threat for any severe storms that
develop over the Upper/Middle Mississippi Valley, while damaging wind
gusts will be the sole threat across the ArkLaTex/Lower Mississippi Valley.

A deepening upper ridge in the West and cutoff low west of Baja will
support a heat wave across much of the Western U.S. over the next several
days. Temperatures will be below average for the Pacific Northwest today
but will be overtaken by warmer conditions beginning on Wednesday. Areas
of particular concern include the low elevation regions of California’s
central valley and the Desert Southwest where high temperatures will
easily climb over 100 degrees beginning today. High temperature anomalies
of 20-30 degrees above average are likely. Widespread temperature records
are expected to be tied or broken across much of the aforementioned areas.
Excessive Heat Warnings and Watches extend from the central valley down
through southern California’s deserts, southern Nevada and
southern/western Arizona. HeatRisk will peak over California’s central
valley on Wednesday before expanding into the Desert Southwest later this
week. Little overnight relief will make for dangerous conditions for those
without effective cooling and/or adequate hydration. HeatRisk over
southern Texas peaks today but persists for the next few days.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Mon Jun 03 2024
Valid 12Z Mon Jun 03 2024 – 12Z Wed Jun 05 2024

…Excessive Rainfall and Severe Weather threaten portions of the
Mississippi Valley and Southern Plains today…

…Increasing Excessive Heat Risk potential over parts of the West and
southern Texas through mid-week…

Shortwave energy spinning through the Northwest will support showers and
thunderstorm activity across the region today. Rainfall rates over the
favored terrain of the Cascades and Northern Rockies will be high enough
to warrant an Excessive Rainfall threat. Thus, a Slight Risk (at least
15%) of Excessive Rainfall leading to Flash Flooding is in effect for
portions of the Northern Rockies, while a Marginal Risk (at least 5%) area
is in place over the Cascades, Olympics and Seattle Metro area. Elsewhere,
showers and thunderstorms are expected to continue over parts of the Great
Plains and Mississippi Valley today. Pockets of severe thunderstorms
capable of producing heavy to excessive rainfall may develop over parts of
the Southern Plains into the Mississippi Valley. Slight Risks of Excessive
Rainfall and Severe Thunderstorms are in effect over those areas, where a
swath of damaging wind gusts are possible. The severe thunderstorm threat
concentrates over parts of the Central Plains and Middle Mississippi
Valley on Tuesday, where a Slight Risk is in effect. Large hail is
possible at the outset when storms are more cellular, but will then be
followed by a congealing of cells into a line of storms with damaging wind
gusts eventually being the main threat.

An upper ridge is expected to develop over the West early to mid-week.
High temperatures will gradually climb into 100s by Wednesday and Thursday
with many records potentially being tied or broken on those days.
Excessive Heat Warnings are in effect for the central valley region of
California while Excessive Heat Watches are in effect for parts of the
Desert Southwest. Extreme HeatRisk is probable to continue for much of
southern Texas through Wednesday. This level of heat risk means that there
will likely be little to no overnight relief for those without effective
cooling and/or adequate hydration.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Jun 02 2024
Valid 12Z Sun Jun 02 2024 – 12Z Tue Jun 04 2024

…Excessive Rainfall and Severe Thunderstorms possible over portions of
the Great Plains and Mississippi Valley…

…Heavy to Excessive Rainfall possible across parts of the Northwest
through Monday…

…Increasing Excessive Heat threat over parts of California, Nevada and
Arizona…

A series of shortwaves will be responsible for Excessive Rainfall and
Severe Thunderstorms that develop across the Great Plains and Mississippi
Valley over the next few days. Today, showers and isolated thunderstorms
will spread from the High Plains into the Mississippi Valley. Some storms
may turn severe. The Storm Prediction Center issued an Enhanced Risk
(level 3/5) of Severe Thunderstorms across portions of the Central High
Plains this afternoon and evening. Very large hail, severe wind gusts
greater than 75 mph, and a few tornadoes are expected. Rain rates in some
of those storms could be high enough to cause flash flooding which is why
there’s a Slight Risk (at least 15%) of Excessive Rainfall over parts of
the Northern/Central Plains and Upper/Middle Mississippi Valley.

Elsewhere, a deep upper low will transport anomalous tropical Pacific
moisture into the Northwest today. Excessive Rainfall is naturally a
concern over the favorable terrain of the Cascades, Bitterrroots, Salmon
River Mountains as well as the Seattle metro, where Slight Risks (at least
15%) are in effect through Monday. Monday will be a Marginal Risk kind of
day for Excessive Rainfall and Severe Thunderstorms over parts of the
Southern/Central Plains and Mississippi Valley. Cloudy/cooler conditions
will prevail over the Northwest thanks to the Atmospheric River event set
to unfold over the next couple of days. Otherwise, the Great Plains and
Northeast are likely to experience above average temperatures this week.
Abnormal heat is expected to expand across parts of the West mid-week.