537
FXUS01 KWBC 211905
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
304 PM EDT WED AUG 21 2024
VALID 00Z THU AUG 22 2024 - 00Z SAT AUG 24 2024
...RECORD HEAT CONTINUES INTO THE END OF THE WEEK ACROSS THE
SOUTHERN PLAINS...
..RECORD COLD DEVELOPS ACROSS CALIFORNIA FRIDAY INTO SATURDAY
...ACTIVE MONSOONAL SHOWERS FOR THE SOUTHWEST INTO THE SOUTHERN
ROCKIES...
...SHOWERY WEATHER ON TAP FOR FLORIDA INTO THE COASTAL SOUTHEAST
AND ACROSS NORTHERN NEW ENGLAND...
THE MID TO UPPER LEVEL FLOW IS EXPECTED TO REMAIN HIGHLY AMPLIFIED
ACROSS THE LOWER 48 OVER THE NEXT TWO DAYS, COMPRISED OF A DEEP
UPPER LOW MOVING SLOWLY ACROSS NEW ENGLAND INTO THE CANADIAN
MARITIMES, ANOTHER STRONG CLOSED LOW DROPPING SOUTH ALONG THE
PACIFIC NORTHWEST COAST AND THE SEEMINGLY EVER PRESENT CLOSED
UPPER HIGH ACROSS THE SOUTHERN PLAINS. THIS MID TO UPPER LEVEL
PATTERN WILL BE SETTING THE STAGE FOR SOME BIG TEMPERATURES
CONTRASTS ACROSS THE CONUS OVER THE NEXT FEW DAYS.
THE PERSISTENT CLOSED UPPER HIGH OVER THE SOUTHERN PLAINS WILL
KEEP THE DANGEROUS HEATWAVE GOING ACROSS THE SOUTHERN PLAINS AS
THE WEEK ENDS THE WEEKEND BEGINS. THE RECENT BATCH OF RECORD HIGH
TEMPERATURES OVER THE SOUTHERN PLAINS WILL CONTINUE OVER THE NEXT
TWO DAYS WITH NUMEROUS RECORD HIGHS POSSIBLE FROM SOUTHEAST NEW
MEXICO INTO LARGE PORTIONS OF TEXAS. HIGH TEMPERATURES ACROSS
THIS REGION WILL BE IN THE 100 TO 110 DEGREE RANGE PRODUCING
WIDESPREAD AREAS THAT WILL EXPERIENCE MAJOR TO EXTREME HEAT RISKS
OVER THE NEXT TWO DAYS. EXCESSIVE HEAT WARNINGS AND HEAT
ADVISORIES ARE CURRENTLY IN EFFECT ACROSS LARGE PORTIONS OF THE
SOUTHERN PLAINS, AFFECTING NEARLY 25 MILLION PEOPLE.
IN CONTRAST TO THE HEAT, BOTH THE EASTERN U.S. AND WESTERN U.S.
WILL SEE BELOW AVERAGE TEMPERATURES OVER THE NEXT TWO DAYS. FOR
THE EAST, AN AREA OF HIGH PRESSURE WILL STRETCH FROM THE
MISSISSIPPI VALLEY TO MUCH OF THE EASTERN SEABOARD, EXCEPT FOR THE
COASTAL SOUTHEAST AND FLORIDA AND NORTHERN NEW ENGLAND. THIS WILL
PRODUCE BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS, ALTHOUGH
TEMPERATURES WILL BEGIN TO MODERATE BACK TOWARD SEASONAL NORMS BY
THIS WEEKEND. THE EXCEPTIONS TO THE DRY WEATHER ACROSS THE
EASTERN HALF OF THE NATION WILL BE ACROSS FLORIDA INTO THE COASTAL
SOUTHEAST AND OVER NORTHERN NEW ENGLAND. A STATIONARY FRONT IS
EXPECTED TO LIE ACROSS NORTH CENTRAL FLORIDA THROUGH THE END OF
THIS WEEK AND INTO THIS WEEKEND, SUPPORTING SHOWERY CONDITIONS FOR
FLORIDA INTO THE COASTAL SOUTHEAST. SHOWERY CONDITIONS ALSO
LIKELY ACROSS NORTHERN NEW ENGLAND NEAR THE AFOREMENTIONED STRONG
CLOSED UPPER LOW MOVING SLOWLY EASTWARD ACROSS THIS REGION OVER
THE NEXT TWO DAYS.
WHILE THE BELOW AVERAGE TEMPERATURES WILL BE WANING ACROSS THE
EAST OVER THE NEXT FEW DAYS, THE MAGNITUDE OF BELOW AVERAGE
TEMPERATURES WILL BE INCREASING ACROSS MUCH OF THE WEST TO THE
WEST OF THE ROCKIES. THIS IS IN ASSOCIATION WITH THE ABOVE
MENTIONED STRONG CLOSED LOW MOVING SOUTHWARD ALONG THE PACIFIC
NORTHWEST COAST. THIS CLOSED LOW WILL HELP PUSH A STRONG COLD
FRONT INLAND FROM THE EASTERN PACIFIC INTO THE PACIFIC NORTHWEST
ON THURSDAY-FRIDAY AND SOUTHWARD INTO CALIFORNIA AND THE GREAT
BASIN FRIDAY AND SATURDAY. MUCH BELOW AVERAGE TEMPERATURES LIKELY
ACROSS THESE AREAS THURSDAY, FRIDAY AND CONTINUING INTO THIS
WEEKEND. THERE IS THE POTENTIAL FOR RECORD COLD AFTERNOON HIGH
TEMPERATURES ACROSS LARGE PORTIONS OF CALIFORNIA ON FRIDAY,
CONTINUING INTO SATURDAY.
BETWEEN THE PACIFIC NORTHWEST CLOSED UPPER LOW AND THE CLOSED
UPPER HIGH OVER THE SOUTHERN PLAINS, ABOVE AVERAGE MONSOONAL
MOISTURE VALUES WILL BE TRANSPORTED NORTHEASTWARD BETWEEN THESE
TWO CIRCULATIONS, BRINGING THE POTENTIAL FOR WIDESPREAD SCATTERED
MONSOONAL SHOWER AND THUNDERSTORMS FOR PORTIONS OF THE SOUTHWEST,
GREAT BASIN AND SOUTHERN ROCKIES. LOCALLY HEAVY RAINS ACROSS THESE
AREAS WILL ALSO POSE THE RISK OF FLASH FLOODS, ESPECIALLY IN AREAS
OF STEEP TERRAIN AND IN SLOT CANYON REGIONS.
ORAVEC
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