962
FXUS01 KWBC 212008
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
407 PM EDT MON AUG 21 2023
VALID 00Z TUE AUG 22 2023 - 00Z THU AUG 24 2023
...THERE IS A SLIGHT OF EXCESSIVE RAINFALL OVER PARTS OF THE
WESTERN U. S. ON MONDAY AND TUESDAY AND SOUTHERN TEXAS ON
TUESDAY...
...THERE ARE AIR QUALITY WARNINGS OVER THE PARTS OF THE PACIFIC
NORTHWEST, CENTRAL ROCKIES, AND MID-ATLANTIC...
...EXCESSIVE HEAT WARNINGS AND ADVISORIES FROM PARTS OF THE
PLAINS, THE MISSISSIPPI VALLEY, AND CENTRAL/WESTERN GULF COAST...
A PLUME OF MOISTURE ASSOCIATED WITH WHAT WAS ONCE HILARY WILL
PRODUCE SHOWERS AND THUNDERSTORMS OVER PARTS OF CALIFORNIA, THE
GREAT BASIN, SOUTHWEST, PACIFIC NORTHWEST, NORTHERN INTERMOUNTAIN
REGION, AND NORTHERN ROCKIES. THEREFORE, THE WPC HAS ISSUED A
SLIGHT RISK OF EXCESSIVE RAINFALL OVER PARTS OF CALIFORNIA, GREAT
BASIN, SOUTHWEST, PACIFIC NORTHWEST, NORTHERN INTERMOUNTAIN
REGION, AND NORTHERN ROCKIES THROUGH TUESDAY MORNING. THE
ASSOCIATED HEAVY RAIN WILL CREATE MAINLY LOCALIZED AREAS OF FLASH
FLOODING, WITH URBAN AREAS, ROADS, SMALL STREAMS, AND BURN SCARS
THE MOST VULNERABLE.
IN ADDITION, THE ASSOCIATED MOISTURE PLUME WILL AID IN PRODUCING
STRONG TO SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHWEST, GREAT
BASIN, AND NORTHERN. THEREFORE, THE SPC HAS ISSUED A MARGINAL RISK
OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHWEST, GREAT BASIN,
AND NORTHERN ROCKIES THROUGH TUESDAY MORNING. THE HAZARDS
ASSOCIATED WITH THESE THUNDERSTORMS ARE FREQUENT LIGHTNING, SEVERE
THUNDERSTORM WIND GUSTS, MINOR THREAT OF HAIL, AND A MINIMAL
THREAT OF TORNADOES.
THE THREAT OF EXCESSIVE RAINFALL CONTINUES ON TUESDAY AS SHOWERS
AND THUNDERSTORMS WITH HEAVY RAIN DEVELOP OVER PARTS OF THE GREAT
BASIN, SOUTHWEST, AND NORTHERN INTERMOUNTAIN REGION. THEREFORE,
THE WPC HAS ISSUED A SLIGHT RISK OF EXCESSIVE RAINFALL WITH THESE
THUNDERSTORMS OVER TWO REGIONS, THE FIRST AREA OVER PARTS OF THE
NORTHERN INTERMOUNTAIN REGION AND THE SECOND OVER PARTS OF THE
GREAT BASIN, ON TUESDAY INTO WEDNESDAY MORNING. THE ASSOCIATED
HEAVY RAIN WILL CREATE MAINLY LOCALIZED AREAS OF FLASH FLOODING,
WITH URBAN AREAS, ROADS, SMALL STREAMS, AND BURN SCARS THE MOST
VULNERABLE.
IN ADDITION, ON TUESDAY, POTENTIAL TROPICAL CYCLONE NINE OVER THE
NORTHERN GULF OF MEXICO WILL STREAM MOISTURE INTO THE WESTERN GULF
COAST, PRODUCING SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN.
THEREFORE, THE WPC HAS ISSUED A SLIGHT RISK OF EXCESSIVE RAINFALL
WITH THESE THUNDERSTORMS OVER PARTS OF THE WESTERN GULF COAST
(SOUTHERN TEXAS) ON TUESDAY. THE ASSOCIATED HEAVY RAIN WILL CREATE
MAINLY LOCALIZED AREAS OF FLASH FLOODING, WITH URBAN AREAS, ROADS,
AND SMALL STREAMS THE MOST VULNERABLE.
ELSEWHERE, A FRONT OVER THE NORTHEAST WILL SETTLE OVER THE
MID-ATLANTIC BY TUESDAY. THE SYSTEM WILL PRODUCE SCATTERED SHOWERS
AND THUNDERSTORMS OVER PARTS OF THE NORTHEAST ON MONDAY EVENING.
IN ADDITION, A WAVE OF LOW PRESSURE OVER THE UPPER MISSISSIPPI
VALLEY WILL PRODUCE SCATTED SHOWERS AND THUNDERSTORMS OVER PARTS
OF THE UPPER MISSISSIPPI VALLEY AND UPPER GREAT LAKES ON TUESDAY.
AS THE WAVE MOVES EASTWARD, SHOWERS AND THUNDERSTORMS WILL DEVELOP
OVER PARTS OF THE GREAT LAKES/OHIO VALLEY ON WEDNESDAY. FURTHER,
ONSHORE FLOW OFF THE ATLANTIC WILL CONTINUE TO PRODUCE SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN TIP OF FLORIDA THROUGH WEDNESDAY.
MOREOVER, WILDFIRE SMOKE OVER PARTS OF THE PACIFIC NORTHWEST,
CENTRAL ROCKIES, AND MID-ATLANTIC HAS PROMPTED AIR QUALITY ALERTS
OVER PARTS OF THE PACIFIC NORTHWEST CENTRAL ROCKIES AND
MID-ATLANTIC ON MONDAY EVENING INTO TUESDAY MORNING.
MEANWHILE, AN UPPER-LEVEL HIGH OVER THE CENTRAL PLAINS/MIDDLE
MISSISSIPPI VALLEY WILL CREATE OPPRESSIVE DAYTIME HEAT, LIMITED
OVERNIGHT COOLING, WHICH WILL ALSO CONTRIBUTE TO THE EFFECTS OF
HEAT, PROMPTING EXCESSIVE HEAT WARNINGS AND HEAT ADVISORIES OVER
PORTIONS OF THE CENTRAL/SOUTHERN PLAINS, THE UPPER/MIDDLE/LOWER
MISSISSIPPI VALLEY, CENTRAL/WESTERN GULF COAST.
IN ADDITION, EXTREMELY DANGEROUS HEAT WILL EXPAND AND INTENSIFY
ACROSS MUCH OF THE CENTRAL U.S., WITH NUMEROUS DAILY
HIGH-TEMPERATURE RECORDS EXPECTED, ESPECIALLY IN TEXAS AND THE
LOWER MISSISSIPPI VALLEY. PARTS OF THE UPPER AND MIDDLE
MISSISSIPPI VALLEY AND CENTRAL PLAINS WILL EXPERIENCE HEAT INDEX
READINGS NEAR OR ABOVE RECORD LEVELS THIS AFTERNOON THROUGH
THURSDAY THIS WEEK. THE EXCESSIVE HEAT THREAT WILL BEGIN TO
RETREAT FROM THE UPPER AND MIDDLE MISSISSIPPI VALLEY LATER THIS
WEEK BEFORE SETTLING OVER THE GULF COAST THIS WEEKEND. TAKE THE
HEAT SERIOUSLY AND AVOID EXTENDED TIME OUTDOORS. TEMPERATURES AND
HEAT INDICES WILL REACH LEVELS THAT WOULD POSE A HEALTH RISK AND
BE POTENTIALLY DEADLY TO ANYONE WITHOUT EFFECTIVE COOLING AND/OR
ADEQUATE HYDRATION.
ZIEGENFELDER
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page