Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Tue Jul 11 2023

Valid 12Z Tue Jul 11 2023 - 12Z Thu Jul 13 2023

...Additional rounds of severe weather and flash flooding persist across
the Plains and Midwest over the next few days...

...Anomalously hot Summer weather forecast throughout much of the Southern
Tier...

...Near average temperatures and generally tranquil conditions for the
Northeast and portions of the West...

A lingering frontal boundary that has led to days of active weather over
portions of the Central/Southern Plains and the Lower Mississippi Valley
will once again be the focus for more showers and thunderstorms and the
risk for heavy rainfall Tuesday in the Lower Mississippi Valley. Ongoing
organized convection early this morning as well as additional development
expected along the front and any lingering outflow boundaries has promoted
a Slight Risk of Excessive Rainfall (level 2/4). Scattered showers and
storms will continue into Wednesday across the Southeast as the
quasi-stationary boundary remains in place. Further north, energetic
northwesterly flow over a southeastward moving frontal boundary will bring
showers and thunderstorms across portions of the Northern/Central Plains
Tuesday and the Midwest Wednesday. Moderately strong flow aloft will lead
to sufficient shear for organized storm development. In accordance, Slight
Risks of severe weather (level 2/5) have been issued by the Storm
Prediction Center for the potential of one or more convective systems
capable of producing large hail and damaging winds. In addition, high
surface moisture and subsequent CAPE will lead to heavy downpours with
high rain rates. There are Slight Risks of Excessive Rainfall for the
Mid-Missouri Valley Tuesday and the Middle Mississippi Valley to Lower
Great Lakes Wednesday for the threat of widespread heavy rainfall totals
from the combination of repeated rounds of storms along the frontal
boundary and the potential development of organized convective systems.
Highs will generally be below average following the passage of the system
over the Northern Plains into the Great Lakes, with highs ranging from the
upper 60s to low 80s. 

An upper-level high over Texas and the Southwest will begin to expand in
coverage over the next couple of days with subsequent
continuation/expansion of anomalously hot Summer heat for the Southern
Tier of the country. Numerous heat-related advisories/watches/warnings are
in effect from Florida to Texas to California. Starting in Florida, highs
in the mid-90s are not significantly above average but relatively
anomalous, with near record-tying/breaking temperatures for some
locations. When combined with the humidity, heat indices will range
between 105-110 degrees. Highs will be in the upper 90s to low 100s for
eastern Texas Tuesday, spreading northward into additional portions of the
Southern Plains and Central Plains Wednesday. High humidity will lead to
heat indices up to 110 here as well. Further west into west Texas as well
as the Desert Southwest, humidity will not be as high but the air
temperature will be hotter, ranging between the mid-100s to mid-110s,
posing a similarly high risk of heat-related impacts. While there may be
some daily fluctuations, the heat is forecast to continue through this
week and into the following week as the broadening upper-level high
remains in place.

Elsewhere, showers will push north and eventually come to an end through
the day Tuesday for New England after multiple days of significant
rainfall over the Northeast. Conditions will clear out in general
following a frontal passage and ahead of increasing precipitation chances
late Wednesday ahead of another system moving in from the west. Highs will
generally be near to just above average for the Mid-Atlantic and
Carolinas, ranging from the upper 80s to mid-90s. After a cool rainy day
in the 70s for portions of northern New England, highs will rebound into
the mid- to upper 80s on Wednesday. Highs will be around average broadly
across the West outside of the Desert Southwest, ranging from the upper
80s to low 90s for the Pacific Northwest and Great Basin to the upper 90s
for the central California Valleys. Highs will be mostly in the 60s and
low 70s for locations along and close to the West Coast.

Putnam


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