108
FXUS01 KWBC 230813
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 AM EDT FRI AUG 23 2024
VALID 12Z FRI AUG 23 2024 - 12Z SUN AUG 25 2024
...MONSOONAL THUNDERSTORMS COULD LEAD TO EXCESSIVE RAINFALL FOR
MUCH OF THE FOUR CORNERS REGION TODAY AND INTO THE WEEKEND...
...RECORD HEAT BEGINS TO RELENT OVER THE SOUTHERN PLAINS THIS
WEEKEND BUT NEAR RECORD COOL IN THE EASTERN U.S. AND CALIFORNIA...
...CRITICAL FIRE RISK AND RED FLAG WARNINGS IN EFFECT ACROSS MUCH
OF THE GREAT BASIN...
AN ANOMALOUSLY AMPLIFIED WEATHER PATTERN ACROSS NORTH AMERICA WILL
CONTINUE TO BRING SHARPLY CONTRASTING WEATHER CONDITIONS ACROSS
THE U.S. AS WE HEAD INTO THE WEEKEND. THIS WEATHER PATTERN WILL
FEATURE A WARM UPPER HIGH OVER THE SOUTHERN PLAINS SANDWICHED IN
BETWEEN TWO DEEP AND COLD UPPER LOWS/TROUGHS ON EITHER SIDE OF THE
WEST AND EAST COASTS. A DEEP AND UNSTABLE SOUTHWESTERLY FLOW
BETWEEN THE RIDGE AND THE UPPER LOW NEAR THE PACIFIC NORTHWEST
WILL SUPPORT MONSOONAL SHOWERS AND THUNDERSTORMS ACROSS THE FOUR
CORNERS REGION THROUGH THE NEXT FEW DAYS, ESPECIALLY EARLY THIS
MORNING WHEN SEVERE THUNDERSTORMS ARE ADVANCING FARTHER DOWNSTREAM
INTO THE CENTRAL PLAINS. SLOT CANYONS AND BURN SCARS ARE
PARTICULARLY VULNERABLE TO FLASH FLOODING. THE FLASH FLOODING
THREAT DWINDLES A BIT HEADING INTO THE WEEKEND AS THE UPPER-RIDGE
SHIFTS SLIGHTLY EASTWARD AND THE MAIN ENERGY ASSOCIATED WITH THE
UPPER LOW WILL BE DIRECTED FARTHER NORTH TOWARD THE NORTHERN HIGH
PLAINS WHERE A NEW LOW PRESSURE SYSTEM IS FORECAST TO FORM BY
SATURDAY NIGHT. MEANWHILE, CRITICAL FIRE WEATHER DANGER IS
FORECAST FOR THE GREAT BASIN UNDER GUSTY AND DRY CONDITIONS BEHIND
A COLD FRONT.
THE LARGE UPPER LOW DIPPING INTO THE PACIFIC NORTHWEST WILL
CONTINUE TO PROVIDE VERY COOL AND DAMP CONDITIONS INTO THE WEST
COAST TODAY. IN FACT, RECORD COOL HIGH TEMPERATURES CAN BE FOUND
TODAY ACROSS CALIFORNIA. THE ANOMALOUS COOL CONDITIONS WILL
PENETRATE FARTHER INLAND DURING THE WEEKEND, OVERSPREADING MUCH OF
THE WESTERN U.S. BY SUNDAY MORNING. IN CONTRAST, ANOTHER
AFTERNOON OF RECORD HIGH TEMPERATURES ARE FORECAST FOR PORTIONS OF
TEXAS INTO OKLAHOMA UNDER THE WARM UPPER HIGH WHERE 110S ARE
POSSIBLE IN PORTIONS OF TEXAS PANHANDLE INTO NEARBY OKLAHOMA.
THIS HEATWAVE IS SHOWING SIGNS OF RELENTING BY THIS WEEKEND AS THE
COOL AIR FROM THE WESTERN U.S. UPPER TROUGH BEGINS TO ERODE THE
UPPER RIDGE. HOWEVER, HEAT INDICES ARE FORECAST TO REACH INTO THE
UPPER 90S TO THE MID 100S DURING THE WEEKEND WHILE THE HEAT BEGINS
TO SPREAD NORTHWARD INTO THE CENTRAL PLAINS.
MEANWHILE, VERY COOL AND PLEASANT WEATHER FOR AUGUST WILL CONTINUE
TO PREVAIL ACROSS MUCH OF THE EASTERN U.S. UNDER THE COOL UPPER
TROUGH TOGETHER WITH A COOL HIGH PRESSURE SYSTEM AT THE SURFACE.
IN FACT, RECORD COOL TEMPERATURES ARE POSSIBLE THIS MORNING ACROSS
PORTIONS OF THE MID-ATLANTIC, CENTRAL APPALACHIANS, AND INTERIOR
SOUTHEAST WITH TEMPERATURES DIPPING AS COLD AS THE 40S. A GRADUAL
WARMING TREND IS EXPECTED THROUGH THE WEEKEND FOR THE EASTERN HALF
OF THE COUNTRY AS THE HIGH PRESSURE SYSTEM BEGINS TO SLIDE OFF THE
EAST COAST.
KONG
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