742
FXUS01 KWBC 210741
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
340 AM EDT SUN MAY 21 2023
VALID 12Z SUN MAY 21 2023 - 12Z TUE MAY 23 2023
...SEVERE STORMS POSSIBLE ACROSS PORTIONS OF THE NORTHWEST AND THE
NORTHERN ROCKIES SUNDAY...
...NORTHERN PLAINS HEATS UP HEADING INTO NEXT WEEK AS TEMPERATURES
ACROSS MUCH OF THE WEST REMAIN ABOVE AVERAGE...
...PRECIPITATION CHANCES AND BELOW AVERAGE TEMPERATURES LINGER
THROUGH MUCH OF THE SOUTH...
AN UPPER-LEVEL TROUGH OFF THE NORTHWEST PACIFIC COAST WILL PUSH A
COLD FRONT EASTWARD THROUGH THE INTERIOR NORTHWEST AND INTO THE
NORTHERN ROCKIES OVER THE NEXT COUPLE DAYS, KEEPING STORM CHANCES
TRENDING UP AND BRINGING AN END TO THE MUCH ABOVE AVERAGE
TEMPERATURES THAT HAVE LINGERED OVER THE REGION FOR MUCH OF THE
PAST COUPLE WEEKS. THE STORM PREDICTION CENTER HAS OUTLINED A
SLIGHT RISK (LEVEL 2/5) OF SEVERE WEATHER AS COOLING TEMPERATURES
ALOFT WITH THE APPROACHING TROUGH OVERSPREAD WARM SURFACE
TEMPERATURES AHEAD OF THE COLD FRONT, LEADING TO ROBUST STORM
UPDRAFTS CAPABLE OF PRODUCING LARGE HAIL. ANOMALOUSLY HIGH
MOISTURE IN THE REGION MAY ALSO LEAD TO SOME HEAVY DOWNPOURS, AND
SOME ISOLATED INSTANCES OF FLASH FLOODING ARE POSSIBLE,
PARTICULARLY AROUND TERRAIN SENSITIVE AREAS AND ANY BURN SCARS.
HIGHS WILL REMAIN IN THE MID-80S TO LOW 90S AHEAD OF THE FRONT
SUNDAY BEFORE TEMPERATURES ACROSS THE REGION SETTLE INTO THE
MID-60S TO MID-70S MONDAY.
MEANWHILE, STUBBORN UPPER-LEVEL RIDGING THAT HAS BEEN IN PLACE
OVER THE WEST WILL SHIFT EASTWARD A BIT, BRINGING THE FOCUS OF THE
MUCH ABOVE AVERAGE TEMPERATURES THAT HAVE BEEN NOTED ACROSS THE
INTERIOR NORTHWEST/NORTHERN ROCKIES EAST INTO THE NORTHERN PLAINS.
HIGHS HAVE ALREADY BEEN WARMING UP OVER THE NORTHERN HIGH PLAINS,
WITH LOW TO MID-80S FORECAST SUNDAY. HIGHS WILL SOAR INTO THE LOW
90S ON MONDAY, WITH MID-80S SPREADING EASTWARD OVER THE NORTHERN
PLAINS. TEMPERATURES WILL ALSO REMAIN ABOVE AVERAGE OVER SOUTHERN
PORTIONS OF THE INTERIOR WEST OUTSIDE OF THE INFLUENCE OF THE
UPPER-LEVEL TROUGH. HIGHS WILL RANGE FROM THE MID-80S IN THE GREAT
BASIN TO THE 90S IN THE CENTRAL CALIFORNIA VALLEYS AND THE LOW
100S IN THE DESERT SOUTHWEST. COASTAL CALIFORNIA WILL BE COOLER IN
THE 60S.
HIGH PRESSURE WILL SETTLE IN OVER THE MIDWEST/NORTHEAST FOLLOWING
THE PASSAGE OF A COLD FRONT PUSHING OFF THE EAST COAST. THIS WILL
KEEP PRECIPITATION CHANCES LOW AND TEMPERATURES MILD, WITH HIGHS
FORECAST IN THE 70S TO LOW 80S. FURTHER SOUTH, THE FRONTAL
BOUNDARY WILL LINGER OVER PORTIONS OF THE SOUTHEAST/FLORIDA,
BRINGING DAILY THUNDERSTORM CHANCES. HIGH MOISTURE POOLING ALONG
THE BOUNDARY WILL LEAD TO SOME LOCALLY HEAVY RAINFALL, WITH
REPEATED ROUNDS OF STORMS POSSIBLE IN THE VICINITY OF THE
BOUNDARY. THIS MAY LEAD TO A FEW ISOLATED INSTANCES OF FLASH
FLOODING. FURTHER WEST, A WEAK WAVE ALOFT EMBEDDED WITHIN THE
LARGE-SCALE UPPER-LEVEL RIDGE WILL HELP TO TRIGGER SHOWER AND
THUNDERSTORMS FOR PORTIONS OF THE CENTRAL/SOUTHERN ROCKIES AND
INTO THE SOUTHERN PLAINS SUNDAY-MONDAY. AS IN THE SOUTHEAST, HIGH
MOISTURE CONTENT LINGERING IN THE REGION AS WELL AS
SLOW-MOVING/CLUSTERING STORMS MAY LEAD TO SOME LOCALLY HEAVY
RAINFALL AND ISOLATED FLASH FLOODING CONCERNS. TEMPERATURES WILL
REMAIN BELOW AVERAGE FOR LATE MAY ACROSS MUCH OF THE REGION
FOLLOWING THE PASSAGE OF THE FRONT, WITH HIGHS IN THE UPPER 70S TO
LOW 80S. CONDITIONS WILL BE WARMER CLOSER TO THE GULF COAST, WHERE
HIGHS WILL BE IN THE UPPER 80S TO LOW 90S.
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