Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Sat Sep 11 2021

Valid 12Z Sat Sep 11 2021 - 12Z Mon Sep 13 2021

...Surge of tropical moisture in the Gulf of Mexico to deliver Excessive
Rainfall to the western Gulf Coast late Sunday and into next week...

...Sizzling temperatures in the the Nation's Heartland and Southwest...

...Severe weather possible from the Northern Plains to the Great Lakes;
Air Quality Alerts continue in the Northwest...

Focusing on the tropics, attention turns to a tropical wave near the
Yucatan Peninsula tracking into the Bay of Campeche on Sunday and into the
northwestern Gulf of Mexico by early this week. The NHC currently gives
this feature a 70% chance for development over the weekend and an 80%
chance over the next five days. Rounds of showers and thunderstorms arrive
along the Texas Coast on Sunday and continue into the upcoming week. As
the atmosphere becomes increasingly favorable environment for shower and
thunderstorm development, excessive rainfall rates and areas of flash
flooding are likely to transpire by Monday. A Day 3 Slight Risk for
Excessive Rainfall has been issued for the Texas Coast in anticipation of
the growing threat for flash flooding on Monday. There remains uncertainty
in whether this tropical wave becomes a named storm early next week and
where the axis of the heaviest rainfall sets up. No matter the tropical
wave's classification, this feature will deliver rich tropical moisture
into southeast Texas and as far north as southwest Louisiana. Interests
along the western Gulf Coast should monitor this situation closely in the
coming days.

Elsewhere, an expansive dome of upper level ridging stretching across the
southern two-thirds of the U.S. mainland means more stifling heat from the
Southwest to the East Coast. Today, the hottest temperatures are focused
in the Central Plains where high temperature anomalies look to range
between 15-20F above normal. Record high temps will also be challenged
throughout the region as temperatures soar above the century mark in
spots. Some record warm minimum temps are expected as far west and the
Great Basin and the Desert Southwest. By Sunday, August-like temperatures
arrive in the Mid-Atlantic and sultry conditions return to the Desert
Southwest. In fact, Excessive Heat Warnings have been issued in parts of
Arizona and the Lower Colorado River Valley for both Sunday and Monday.
The coolest temperatures will be confined to the Pacific Northwest and the
Northern Plains.

An elongated frontal boundary stretching from southeast Canada to the
northern High Plains is set to trigger daily episodes of showers and
thunderstorms today and Sunday. The Upper Great Lakes and central High
Plains/Rockies have the best odds for witnessing scattered showers and
storms today. The front progresses east into the Northeast by Sunday,
leading to a renewed chance for storms across the region while the central
and northern High Plains remain at risk for additional severe weather.
Farther south, a lingering frontal boundary over Florida helps to spawn
hit-or-miss showers and storms each day across the Sunshine State. Last
but not least, raging wildfires in the West continue to generate massive
amounts of smoke that is sweeping across the country. Air Quality Alerts
remain in effect in the Northwest and northern High Plains while smoke
high up in the atmosphere will make for discolored skies and potentially
vivid sunrises and sunsets from the Plains to the East Coast.

Mullinax

Graphics are available at www.wpc.ncep.noaa.gov/basicwx/basicwx ndfd.php